Kingfisher Biotech

Guinea Pigs as an Animal Model of Human Disease

2012-02-05T19:40:00.000-06:00

The guinea pig was first established as a valuable biomedical model in the field of bacterial disease in the 1800s and early 1900s, with works published on tuberculosis and diphtheria using guinea pig models each earning Nobel Prizes. While guinea pigs are a bit more expensive than mice and still lack the abundance of genomic and proteomic tools currently available for mice, they do offer several unique and important advantages. [1,2]

Biologically, guinea pigs have recently been re-classified as a non-rodent species and in many ways reproduce human disease more closely than rodents in terms of pathology and histology and therefore offer a more translatable model for the development and testing of new therapies. In particular, guinea pigs have greater similarities to humans (as compared to mice) in pulmonary physiology, innate and adaptive immune system physiology, the lack of ability to endogenously synthesize vitamin C, and many other aspects. Specifically, the guinea pig immune system has been heavily studied and found (again, as compared to mice) to have complement systems more similar to humans, infection-induced IFN-γ and iNOS expression patterns more similar to humans, and a number of important immune system genes including IL-12 p35 and p40, RANTES, CD8, and Leukocyte Antigen more similar to humans at the nucleotide or amino acid sequence levels. Further, unlike mice and rats, guinea pigs express a number of human-like CD1 homologs and express both IL-8 and its receptor CXCR1. [1,2]

Experimentally, guinea pigs are docile and easy to handle and are considered one of the smallest models with immunological relevance to humans. Further, they are less expensive to purchase, house, and breed than most of the other relevant animal models and experience short disease time courses, which facilitates rapid assessment of disease progression and testing of potential therapies. [1,2]

Currently, the Kingfisher Biotech portfolio of recombinant Guinea Pig proteins, includes CCL2 (MCP-1), CCL5 (RANTES), CCL11 (Eotaxin-1), CXCL1 (GRO alpha), IL-1 beta, and IL-8 (CXCL8).

References
1. Padilla-Carlin, D. et al. (2008) The guinea pig as a model of infectious diseases. Comp. Med. 58(4):324-340.

2. Hicky, A.J. (2011) Guinea pig model of infectious disease - viral infections. Curr. Drug Targets 12(7):1018-1023.

TNF alpha Homology Across Species

2011-11-14T19:21:00.001-06:00

TNF alpha is involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction. It is produced mainly by activated macrophages.

TNF alpha is able to induce fever, apoptotic cell death, sepsis (through IL-1 & IL-6 production), cachexia, and inflammation, as well as to inhibit tumorigenesis and viral replication. Because of the broad role of TNF alpha, dysregulation has been implicated in a variety of diseases.

Rabbit as an Animal Model for Tuberculosis Research

2011-11-07T12:53:00.000-06:00

The three main animal models employed for the study of tuberculosis (TB) pathogenesis in humans are rabbits, guinea pigs, and mice. All three of these species have the advantages of closely approximating clinical observations as they can be infected by inhalation, display both innate and adaptive immune responses, and generally control the infection initially before it finally becomes fatal. Human TB pathogenesis is a very complex process and no one animal model represents all aspects of the disease. However, rabbit models of TB have the further advantages of displaying cavitation and arrested infection. [1,2]

Rabbit is the only experimental model in which pulmonary cavitation occurs. Pulmonary cavities in rabbits and humans contain huge populations of TB bacteria (~108), which have access to the bronchial tree and therefore the external environment. Given that the degree of contagiousness of TB in humans is typically judged by bacillary burden in sputum culture, the study of cavitation in rabbits is critical to our understanding of TB transmission in humans. Further, the immune systems of rabbits are capable of arresting infection such that they display a latent, or paucibacillary, state similar to humans and in some cases are capable of controlling TB infection so effectively that the bacilli appear to have been completely cleared. While reactivation from a latent state is spontaneous in humans, rabbit reactivation requires immunosuppression. These features make rabbit an important model for the study of human latent TB. [1,2]

References
1. Bosze, Z. and Houdebine, L.M. (2006) Application of rabbits in biomedical research: a review. World Rabbit Sci. 14:1-14.
2. Dharmadhikari, A. and Nardell, E.A. (2008) What animal models teach humans about tuberculosis. Am. J. Respir. Cell Mol. Biol. 39:503-508.

Rabbit as an Animal Model for Osteoarthritis Research

2011-10-30T13:51:00.000-05:00

In humans, osteoarthritis (OA) develops either idiopathically and progresses slowly with age or secondarily to trauma and progresses rapidly. OA is associated with changes to all joint tissues including articular cartilage, subchondral bone, synovium, ligaments, and muscles. Clinically, OA-mediated joint damage results in reduced mobility, pain, and fatigue. While several disease modifying OA drugs are in various stages of development, none have yet been approved for human use. Concurrent research in humans as well as experimental animal models will be important for the discovery of new therapeutics. Since no single experimental model provides the complete picture of OA in humans, a variety of animals have served to advance OA research including mouse, rat, guinea pig, rabbit, dog, and horse. [1,2]
A broad range of rabbit OA models have been used extensively and continue to offer specific advantages over other models for OA research. The gross anatomy of the rabbit knee is very similar to that of humans. Moreover, the rabbit knee joint is large enough to enable the harvest of adequate volumes of tissue for histopathological analysis, a major limitation of smaller animal models. In adult humans, the growth plates in the long bones no longer retain the capacity for growth and are termed “closed.” This is also the case in skeletally-mature rabbits. By contrast, mouse and rat growth plates do not normally close completely and longitudinal bone growth can be reinitiated even in mature animals. This is a complicating issue for data interpretation and limits the translatability of research performed using mice and rats. [2]
Most often, skeletally-mature, male, NZW rabbits are used for OA studies in an attempt to ensure bone growth plate closure, reduce hormone fluctuation, and control for potential inter-strain variability. OA does not occur spontaneously in rabbits, but can be induced via surgical intervention (i.e., meniscectomy or anterior cruciate ligament transection [ACLT]), mechanical manipulation (i.e., impact or immobilization), or chemical application (i.e., IL-1β, collagenase, etc.). The majority of rabbit OA studies employ the ACLT model as it offers several advantages. ACLT-modified rabbits very quickly develop a wide variety of cartilage lesions post-surgically, which closely approximate many aspects of human OA. The histopathology of the rabbit ACLT model has been studied extensively and a standardized nomenclature and scoring scheme for evaluating and comparing alterations in joint structures, including changes in cartilage, synovium and bone, have been proposed. Further, a sizeable body of data derived from this model has already been amassed describing OA pathogenesis including imaging studies and effects of various potential pharmacological applications. [2]
References
1. Poole, R. et al. (2010) Recommendations for the use of preclinical models in the study and treatment of osteoarthritis. Osteoarthritis Cartilage 18(Suppl. 3):S10-S16.
2. Laverty, S. et al. (2010) The OARSI histopathology initiative – recommendations for histological assessments of osteoarthritis in the rabbit. Osteoarthritis Cartilage 18(Suppl. 3):S53-S65.

Rabbit as an Animal Model for Eye Research

2011-10-23T13:29:00.000-05:00

The main advantages to using rabbits as experimental models in eye research are the large size of the rabbit eye relative to its body and the several hundred years worth of accumulated data on the anatomy and physiology of the rabbit eye and its similarity to the human eye. Added to that, the fact that rabbits are easy to handle and breed and the most economical of the larger breed models, makes them ideal for ophthalmic research. [1]

The main avenues of eye research using the rabbit as a model are related to surgical interventions including cataract removal, intraocular lens insertion, corneal transplantation, laser refractive procedures, glaucoma shunt implantation, and intra-vitreal drug delivery. Strain selection is an important consideration for these experiments as the strain most commonly available is albino (New Zealand White [NZW]). Other strains are available that more closely approximate human ocular pigmentation (New Zealand/Dutch Belt or Dutch Belt) for experiments were pigmentation is important. Though there are no differences among male and female rabbits studied using these types of procedures, there are significant age-related differences. For example, young rabbits are commonly used because they have a more robust post-operative inflammatory response, which has been described as similar to that clinically observed in small children. [1]

Other areas of active biomedical research using the rabbit eye as a model include retinal detachment and proliferative vitreoretinopathy (PVR), retinoblastoma, and retinitis pigmentosa (RP). PVR is an abnormal wound healing process that takes place commonly after retinal detachment or other ocular trauma, resulting in a highly inflammatory environment within the eye. Treatment of PVR by vitrectomy or non-specific pharmacological prevention of cell proliferation are only marginally successful. Understanding intra-ocular inflammation is critical to developing new therapeutics for PVR and the rabbit PVR model will undoubtedly facilitate that effort. [2] A new model of retinoblastoma, created by injection of cultured human retinoblastoma cells into the sub-retinal space of immunosuppressed rabbits, displays intraocular tumors after one week that are remarkably similar to those observed in humans and that continue to grow for up to eight weeks. This model also has the advantage of developing viable vitreal tumor seeds when the retinal tumor is still only mid-sized. These vitreous seeds only develop very late in mouse models and are thought to be the cause of treatment failures in humans. This model presents the opportunity to test potential novel chemotherapeutics as well as delivery methods. [3] A new model of RP has been developed via creation of transgenic rabbits bearing a point mutation in the rhodopsin gene. The model has been characterized histologically and electrophysiologically and determined to display progressive retinal degeneration as a result of loss of rod function. While other animals currently serve as models for RP, this new rabbit model will offer additional options for testing therapeutic strategies including implantation of devices or prosthetics and local delivery of drugs or gene therapy. [4]

References
1. Gwon, A. (2008) The rabbit in cataract/IOL surgery. In: Tsonis, P.A. (ed.) Animal models in eye research. Elsevier, pp. 184-204.

2. Zahn, G. et al. (2010) Assessment of the integrin α5β1 antagonist JSM6427 in proliferative vitreoretinopathy using in vitro assays and rabbit model of retinal detachment. Invest. Ophthalmol. Vis. Sci. 51(2):1028-1035.

3. Kang, S.J. and Grossniklaus, H.E. (2011) Rabbit model of retinoblastoma. J. Biomed. Biotechnol. 2011:394730.

4. Kondo, M. et al. (2009) Generation of a transgenic rabbit model of retinal degeneration. Invest. Ophthalmol. Vis. Sci. 50(3):1371-1377.

Rabbit as an Animal Model of Alzheimer's Disease

2011-10-17T09:25:00.002-05:00

As a result of the rarity of spontaneous Alzheimer’s disease (AD) development in non-human species, animal models mimicking various aspects of this disease have only recently been innovated – typically via dietary, pharmacological, or genetic manipulations. Of these new experimental AD models, the rabbit hypercholesterolemia model, originally developed for the study of atherosclerosis (described above), has a variety of advantages that make it one of the leading models for AD research as well. [1]

Physiologically at the cellular and molecular levels, rabbits fed high-cholesterol diets display many of the neuropathologies observed in humans with AD. The brains of these rabbits show increased levels of cholesterol and Amyloid β (Aβ) and decreased levels of acetylcholine, increased Aβ, tau, and ApoE immunoreactivity, Aβ plaques in the extracellular space, a breakdown in the blood-brain barrier, and an increase in microglial and decrease in neuronal cell populations. The phylogenetic proximity of rabbits and humans is reflected in the 97% amino acid sequence conservation observed between the two species’ Aβ proteins and is a major advantage over other models of AD including fruit flies, mice, and rats. Anatomically, rabbits have larger brains relative to the aforementioned species allowing for greater flexibility in testing for cognitive impairment. Cognitively, rabbits with hypercholesterolemia-induced AD display age-dependent deficits in associative learning that closely parallel those observed in humans. As measured by impairment of eyeblink classical conditioning, these deficits are beyond those observed with normal aging, are specific to AD (i.e., not observed in Parkinson’s Disease or Huntington’s disease), and are relieved upon administration of drugs that improve cognition. No other experimental animal model of AD boasts such an extensive body of existing data by which to judge cognitive impairment as the classically-conditioned eye blink response of rabbits. [1]

Reference1. Woodruff-Pak, D.S. (2008) Animal models of Alzheimer’s disease: therapeutic implications. J. Alzheimers Dis. 15(4):507-521.

Rabbit as an Animal Model for Atherosclerosis

2011-10-13T22:50:00.001-05:00

Atherosclerosis naturally occurs only in humans, a few non-human primates, and pigs. Rabbits, being herbivores, do not develop atherosclerosis naturally, but do consistently develop an atherosclerotic condition that very closely resembles clinical observations when manipulated via dietary or genetic interventions. The rabbit hypercholesterolemia model is perhaps the most well-know of the models and is typically produced by feeding intact rabbits a high-cholesterol diet. After only a few weeks on a modified diet, rabbits develop notable vascular lesions. This rabbit model is highly reproducible with minimal variation between animals in a single laboratory and between laboratories. Two spontaneous lipid metabolism mutants have been characterized and also used extensively in atherosclerosis research – the Watanabe heritable hyperlipidemic (WHHL) rabbit (LDL receptor deficient) and the St. Thomas’ Hospital rabbit (VLDL, IDL, and LDL elevated) serve as models for familial hypercholesterolemia and familial combined hyperlipidemia, respectively. Homozygous WHHL rabbits and St. Thomas’ Hospital rabbits predictably develop atherosclerotic lesions on normal diets. Finally, there are at least 19 transgenic rabbit lines now available specifically for the study of cardiovascular disease that express a wide variety of human transgenes many of which code for proteins implicated in atherosclerosis. [1-3]

These rabbit models closely approximate a variety of aspects of human atherosclerosis and are commonly used to study atherogenesis, plaque instability and rupture, and myocardial infarction. Relative to rodent models, rabbits are much more clinically relevant as many aspects of rabbit lipoprotein metabolism are very similar to humans. Perhaps the most notable differences are that rabbit vascular lesions are more fatty and more inflammatory (as measured by numbers of macrophages present) and rabbit circulating cholesterol levels are higher. An additional advantage to rabbits over rodents is that human transgenes expressed in rabbits produce the expected human-like symptoms while the same transgenes expressed in rodents fail to do so. Further, rabbits are capable of tolerating longer experimental protocols that require monitoring and/or sampling over a period of time whereas individual rodents often can only contribute to a single time point in a study. [1-3]

Rabbit is the first and classical model for human atherosclerosis research and will continue contribute pre-clinical, translational evidence for the safety and efficacy of novel therapies. Perhaps the only animal models that have in some cases surpassed the value delivered by rabbits are the swine models. [1-3]

1. Bosze, Z. and Houdebine, L.M. (2006) Application of rabbits in biomedical research: a review. World Rabbit Sci. 14:1-14.

2. Badimon, L. et al. (2008) Models of behavior: cardiovascular. In: Conn, P.M. (ed.) Sourcebook of models for biomedical research. Humana Press, pp. 361-368.

3. Kónya, A. et al. (2008) Animal models for atherosclerosis, restenosis, and endovascular aneurysm repair. In: Conn, P.M. (ed.) Sourcebook of models for biomedical research. Humana Press, pp. 369-384.

Rabbit as an Animal Model of Human Disease

2011-10-10T09:16:00.000-05:00

In the context of biomedical research, rabbits are perhaps most often thought of as bioreactors for the production of monoclonal and polyclonal antibodies and more recently recombinant proteins. However, rabbits are increasingly becoming a valuable experimental model in their own right and are in some cases, the translational model of choice. [1]

Rabbit models do not have the litany of advantages afforded by rodent, or for that matter invertebrate, models in terms of their short life spans, short gestation periods, high numbers of progeny, low inter-individual variability, low cost, advanced genomics and proteomics, and broad availability of reagents. However, rabbits do have many advantages and serve to bridge the gap between these small animal models, which are perhaps best suited for discovery phases of research, and larger animal models often required for pre-clinical, translational research. Rabbits are relatively inexpensive to purchase, house, and maintain as compared to larger animal models. They are easy to breed and handle and are a well-established model in terms of being recognized by the scientific and regulatory communities. Rabbits are phylogenetically closer to primates than rodents and further offer a more diverse genetic background than inbred and out-bred rodent strains, which makes the model a better overall approximate to humans. Further, rabbit genomics and proteomics are advancing rapidly and several transgenic lines have been created and characterized and are readily available. With more researchers using rabbits in their experiments, industry is catching up to their needs and offering an expanding range of rabbit-specific products and services to support them. [1]

Perhaps most importantly, there are some human conditions that cannot be adequately modeled by invertebrate or rodent species and in some cases, the special characteristics of rabbit anatomy and physiology make it uniquely suitable for the study of particular human diseases. [1] Some of the fields for which the rabbit often serves as a primary experimental model include atherosclerosis, Alzheimer’s disease, eye research, osteoarthritis, and tuberculosis. Below is a brief description of how rabbits are crucial to furthering research in these selected areas. This review is intended to be neither comprehensive nor definitive, rather an overview of selected biomedical research fields that employ the rabbit model.

References1. Bosze, Z. and Houdebine, L.M. (2006) Application of rabbits in biomedical research: a review. World Rabbit Sci. 14:1-14.

IL-17A Homology Across Species

2011-09-28T14:44:00.001-05:00

IL-17A is a member of the IL-17 family, which is comprised of 6 members [IL-17A, IL-17B, IL-17C, IL-17D, IL-17E (also called IL-25), and IL-17F]. IL-17 family members are involved in numerous immune regulatory functions, including inducing and mediating proinflammatory responses and allergic responses. Il-17 induces the production of many other cytokines (IL-6, G-CSF, GM-CSF, IL-1beta, TGF-beta, and TNF-alpha), chemokines, including IL-8 (CXCL8), GRO-alpha (CXCL1) and MCP-1 (CCL2) and prostaglandins from many cell types (fibroblasts, endothelial cells, epithelial cells, keratinocytes and macrophages).
Kingfisher Biotech has a growing portfolio of IL-17A products across many species.

IL-17A Homology Across Species

Canine as an Animal Model of Human Disease

2011-09-08T08:19:00.003-05:00

Domesticated dogs are increasingly being identified as good models for a variety of biomedical research fields as they have a number of unique advantages over other commonly used experimental animals. Perhaps the most interesting of these is the fact that dogs cohabitate with their owners, are kept into their old age, and generally receive a good level care including highly-trained healthcare. This modeling of the human condition offers valuable opportunities for researchers to examine complex problems such as environmental contributions to diseases, aging and its effect on disease susceptibility and progression, and the effects of long-term treatment protocols. [1-3]

Another advantage is that over the past several centuries, domestication and selective breeding of dogs has resulted in nearly 400 distinct populations and thus the most naturally occurring genetic diversity in any one species besides humans. Careful breeding for trait selection has inadvertently resulted in breed-specific disease susceptibilities and approximately 400 naturally-occurring, inherited diseases have been identified in dogs. Most predicted canine genes have known human homologs and several of these heritable canine diseases have been associated with mutations in canine and human homologous genes. The enormous genetic diversity of canine breeds (many of which have extensive pedigree information) and the broad range of spontaneously-occurring canine diseases afford researchers opportunities to examine genetic etiologies and explore the possibility of gene therapies. Unfortunately, this genetic diversity is also the main disadvantage of canine models as there are breed-specific differences in physiology and metabolism, especially idiosyncrasies in pharmacodynamics and pharmacokinetics, which can introduce complications when interpreting or translating results. However, increasing research in this area is expanding on our current understanding of these issues. [1-3]

Finally, due to the rapid aging of dogs, there is a shorter duration for disease development and progression. This is an enormous advantage in the context of drug development as clinical trial study times are significantly reduced. Potential for rapid study times along with reduced regulatory guidelines and the increasing acceptance of canine models of human diseases by regulatory bodies is resulting in the growing use of dogs as models for translational medicine. Canine models have already served to advance human medicine in a number of areas and have been instrumental in some, such as narcolepsy, hemophilia, retinal degeneration, and muscular dystrophy. [1-3] A brief overview of a selection of biomedical research fields in which canine models are used is described here. This summary should be taken as neither comprehensive nor definitive.

Cancer
Dogs are particularly good models for the study of cancer. They spontaneously and with high frequency develop the same types of cancers that humans do and are often even treated with the same therapeutic strategies. Additionally, the centuries of selective breeding of dogs confers opportunities to examine polymorphisms specific to particular breeds that have exaggerated incidences of cancer subtypes. Finally, because dogs cohabitate with their owners, they are both exposed to the same environmental factors that may potentiate the development of cancer. This offers an exceptional opportunity to look at the interactions between genetics and environment in the etiologies of various forms of cancer. A wide variety of cancers are being studied in dogs including soft tissue sarcomas, mammary carcinomas, primary and secondary lung carcinomas, malignant melanomas, and cancers of the prostate, bladder, intestine, brain, mouth, and many others. In the interest of brevity, only two forms of cancer for which canine models are used will be highlighted here. [1,4]

Non-Hodgkin’s Lymphoma (NHL)
Approximately 5% of all human cancers are one of several forms of lymphoma. Non-Hodgkin’s lymphoma (NHL), in particular, is increasing in incidence yet is still of unknown etiology. Dogs are an excellent model for human lymphomas as they spontaneously develop the disease with high frequency, accounting for nearly 25% of all life-threatening canine cancers. In dogs and humans, NHL is most commonly the diffuse large B-cell variety and is treated with the same therapeutic strategies. The canine breeds with disproportionately high incidences of diffuse large B-cell type NHL are Boxers and Golden Retrievers. Research using these breeds has led to a better understanding of lymphoma cytogenetics, which suggests the pathogenic origin of lymphoma is very similar between humans and dogs. NHL-afflicted dogs serve as models for the testing of new drugs, drug delivery methods, and immunotherapies, as well as modified diets and other treatment strategies. For example, preclinical testing of a selective, irreversible inhibitor of B-cell activation and an anti-human leukocyte antigen (HLA) monoclonal antibody are ongoing and showing promising results so far. [1,4]

Osteosarcoma (OSA)
Although relatively rare in humans, osteosarcoma (OSA) is of particular interest as it mainly affects children and adolescents and is very aggressive (80% metastatic rate) and notoriously resistant to chemotherapy (more than 30% of patients are unresponsive to available drug regimens). Sadly, the 5-year, post-diagnosis survival rate for metastatic OSA patients is only 20%. Like human OSA, canine OSA is most common in heavy individuals, is generally confined to bone (particularly long bones), and has similar metastatic rates (90% in dogs) and destinations (lungs and soft tissues). Large breeds such as Great Dane, Wolfhound, and Rottweiler are most susceptible to OSA and genetic features found in OSA-afflicted individuals of these breeds appear to be reflected in human OSA sufferers as well. For example, both human and canine OSA sufferers display similar alterations in the p53 tumor suppressor pathway. Candidate genes identified in both humans and dogs include the c-Met proto-oncogene (a.k.a. hepatocyte growth factor [HGF] receptor), the chemokine IL-8 (a.k.a. CXCL8), and several others. Elevated, co-expression of both HGF and c-Met is observed in both human and canine OSA tumors and in humans is associated with increased tumor growth, invasion, and metastasis. Over-expression of IL-8, is observed in canine OSA tumors and in human tumors from patients with especially poor outcomes. Closer examination of these and other candidate genes in dogs and in humans will undoubtedly lead to a better understanding of OSA pathophysiology and more effective, targeted therapies. [1,2,4]

Aging & Alzheimer’s Disease
There are significant breed-specific differences in canine longevity – smaller breeds having longer lifespans and larger breeds having shorter lifespans. Generally, the Beagle has been selected as the main breed used for aging studies as its median lifespan is 12 to 14 years, and Beagles over 9 years of age are considered “old,” representing humans aged 66 to 96 years. Both cognitive and neuropathological changes in aged Beagles have been well documented and seem to closely approximate human clinical observations in many aspects. These features make dogs, and in particular Beagles, well-matched for studies of human aging and age-related conditions such as Alzheimer’s disease (AD). [5]

Like humans, aged dogs naturally suffer from AD that is characterized by the deposition of significant amounts of Amyloid β (Aβ) protein and the development of diffuse plaques, the extent of which quantifiably correlate with cognitive decline. However, AD-afflicted dogs do not appear to naturally develop neurofibrillary tangles as observed in humans. This may be explained by the fact that while the Aβ amino acid sequence is identical in dogs and humans, the Tau amino acid sequence is appreciably different in the two species. It has been suggested that presence of Aβ deposits and plaques and lack of neurofibrillary tangles represents early stages of AD, which may uniquely position the canine AD model for investigations into the possibilities of preventative measures and early interventions. Therapeutic strategies under investigation using canine AD models include antioxidant diets and behavioral enrichment. Both of these regimens have been shown to improve AD pathology when delivered individually and even more so when administered in combination. Other treatment strategies being pursued in dogs include disruption of Aβ processing by anti-inflammatory or statin drugs and immunization against Aβ peptide. [5,6]

Respiratory Disease
Dogs have been commonly used for the study of human respiratory system function and dysfunction and as a consequence, an extensive body of literature describing canine pulmonary anatomy and physiology already exists and includes data related to lung mechanics, ventilation, and cough reflex, immunobiology and inflammation, pharmacology, and central neuronal control mechanisms. Further, their large size and easy handling make dogs ideal for long-term studies of the effects of inhaled irritants such as common components of air pollution (i.e., ozone or SO2) and cigarette smoke. There are many similarities between human and canine respiratory systems and dogs have been used particularly as models for chronic inflammatory diseases such as asthma and chronic obstructive pulmonary disease (COPD), which develops from chronic bronchitis and emphysema. [7]

Asthma
Asthma induced in healthy canine subjects via challenge with antigen, hyperventilation, or ozone results in classical characteristics of asthma in humans – airway hyperresponsiveness and chronic inflammation that results in bouts of wheezing, chest tightness, breathlessness, and coughing. While canine pulmonary responses to each of these asthma-inducing methods are slightly different in some aspects, the commonalities are significant and closely parallel clinical observations of patients with asthma. In general, dogs with induced asthma acutely display changes in the mechanics of airway constriction and increases mast cell mediators including histamine, prostaglandin D2, thromboxanes, serotonin, and vasoactive peptides. This is associated with significant damage to airway mucosa and some of these mediators (i.e., histamine, serotonin, and bradykinin) are known to directly stimulate sensory afferents in the lungs and subsequently affect central control of airway function. Chronically, dogs with induced asthma display airway hyperresponsiveness and chronic inflammation. Airway hyperresponsiveness is characterized by rapid bronchoconstriction at magnitudes 2 to 10-fold greater than normal and by destruction of airway epithelium possibly as a result of reduced bronchoprotective prostaglandin E2. Asthma-associated, chronic inflammation in lung tissues is characterized by neutrophil, eosinophil, and T lymphocyte infiltration as well as mobilization of new bone marrow progenitor cells to lung tissues. These canine models of induced asthma display many similarities with human asthma and serve as good models for the study of the disease and potential therapeutic strategies. [7]

Chronic Obstructive Pulmonary Disease (COPD)
Although dogs naturally develop both chronic bronchitis and emphysema, COPD is most typically studied in induced models – where normal healthy dogs are subjected to inhalation of cigarette smoke, SO2 gas, or aerosolized proteolytic enzymes. In general, short-term exposure to these inhaled irritants results in pulmonary reflexes such as increased cough frequency and mucous production as well as bronchoconstriction. Further, there is evidence of edema, inflammation characterized by neutrophil and macrophage infiltration, alteration of airway mucous glands, and damage to airway epithelium. These pathological changes in the lungs closely resemble human chronic bronchitis. Longer-term exposure, in some cases, results in pathological changes in lung tissues resembling emphysema – alveoli enlargement and destruction and remodeling of lung parenchyma. [7]

Endocrinopathies
A variety of endocrine disorders known to affect humans also occur spontaneously in dogs. Some examples of such endocrinopathies include diabetes, growth hormone (GH) dysfunctions (i.e., dwarfism or acromegaly), and hypercortisolism (a.k.a Cushing’s disease). Canine diabetes is caused either by autoimmune destruction of pancreatic β-cells or excess in counter-regulatory hormones (i.e., hypercortisolism). Pituitary dwarfism in dogs is caused by autosomal recessive combined pituitary hormone deficiency (CPHD), which is often observed particularly in the German Shepherd breed. Canine CPHD is characterized by combined reduced levels of GH, thyrotropin, prolactin, and gonadotropins due to poor development of the pituitary gland and may be a good model for human CPHD. GH excess in dogs often leads to canine acromegaly. In this context, progesterone induces excess GH production in the mammary gland. This mechanism is also associated with up-regulation if insulin-like growth factor (IGF) and IGF binding protein (IGFBP) production. Together, these alterations in normal physiology in canine mammary tissue promote proliferation and appear to play a role in the development and/or progression of canine mammary tumors and hence may offer some insight into human breast cancer. [8]

Cushing’s Disease
In humans and dogs, Cushing’s disease is caused by adrenal cortex over-production glucocorticoids (GCs). Endogenous excess GC production is most often the result of pituitary adenoma (80 to 85% of cases) and less often the result of adrenocortical adenoma (15 to 20% of cases) in both species. Although relatively rare in humans, middle-aged to old dogs commonly develop Cushing’s disease with manifestations very similar to clinical observations in humans including changes in the skin, weight gain and abdominal obesity, fatigue and muscle atrophy, and hypertension and renal dysfunction. Because of these similarities between canine and human Cushing’s disease, the high frequency of spontaneous disease in dogs, and the fact that canine pituitary and adrenal glands are relatively large (i.e., compared to smaller animal models) and therefore easier to handle for histological, in vitro, and ex vivo studies make dogs excellent models for this disease. [8,9]

References
1. Rowell, J.L. et al. (2011) Dog models of naturally occurring cancer. Trends Mol. Med. Epub ahead of print, Mar 23.

2. Fleischer, S. et al. (2008) Pharmacogenetic and metabolic differences between dog breeds: their impact on canine medicine and the use of the dog as a preclinical animal model. AAPS J. 10(1):110-119.

3. Tsai. K.L. et al. (2007) Understanding hereditary diseases using the dog and human as companion model systems. Mam. Genome 18(6-7):444-451.

4. Porrello, A. et al. (2006) Oncology of companion animals as a model for humans: an overview of tumor histotypes. J. Exp. Clin. Cancer Res. 25(1):97-105.

5. Cotman, C.W. and Head, E. (2008) The canine (dog) model of human aging and disease: dietary, environmental and immunotherapy approaches. J. Alzheimers Dis. 15(4):685-707.

6. Woodruff-Pak, D.S. (2008) Animal models of Alzheimer’s disease: therapeutic implications. J. Alzheimers Dis. 15(4):507-521.

7. Chapman, R.W. (2008) Canine models of asthma and COPD. Pulm. Pharmalol. Ther. 21(5):731-742.

8. Kooistra, H.S. et al. (2009) Endocrine Diseases in Animals. Horm. Res. 71(Suppl. 1):144-147.

9. Smets, P. et al. (2010) Cushing’s syndrome, glucocorticoids, and the kidney. Gen. Comp. Endocrinol. 169(1):1-10.

Swine as a Animal Model for Traumatic Brain Injury, Stroke, and Neurodegenerative Disease

2011-09-05T06:37:00.000-05:00

While swine have historically not been used as a model for the human central nervous system due to their enormous skull bones and vertebrae and very narrow intervertebral spacing, their appearance in the neuroscience literature has been rapidly increasing. Swine have relatively large brains that are anatomically more similar to humans than rodents in that they are gyrencephalic, contain more white matter, and have similar patterns of cerebral blood flow. [1]

Because swine also display a very human-like progression of early brain development, neonatal swine have become a particularly interesting new model of pediatric traumatic brain injury (TBI) and stroke. TBI is characterized by primary distortion of the parenchyma and secondary excitotoxicity, cell death, axonal injury, cerebral swelling, and inflammation. Swine and human responses to TBI are very similar and have been well characterized in terms of arterial and intracranial pressures, cerebral blood flow, histopathology, and a variety of other measures. Further, simple functional testing using a veterinary coma scale and complex neurobehavioral testing to assess functional outcome of TBI-treated swine are documented. This enables researchers to determine whether novel neuroprotective therapies offer significant improvement in neurological outcomes. [11] Ischemic stroke in pediatric patients is mechanistically different than observed in adults and thus suggests treatment regimens be age-specific. However, there is still relatively little known about stroke in children as options for animal models have been limiting. A new neonatal swine model reliably produces clinically-relevant ischemic stroke in both grey and white matter that upon histopathological analysis shows evidence of platelet activation, thrombus formation, apoptosis, and localized accumulation of inflammatory leukocytes. The model also, as a result of the large size of piglets relative to rat pups for example, facilitates collection of other important physiological measurements including blood pressure and oxygen saturation. [12]

Large animal models are particularly important for the study of human neurodegenerative diseases as rodent models cannot approximate the size and gross anatomy of human brains much less their neuroanatomical connectivity and cognitive capacity. Monkey and swine are the most human-like neurological models described to date and are critical for bridging the gap in neurodegenerative disease research between basic discovery science performed in rodents and clinical trials for human therapeutics. Swine models of Parkinson’s disease (PD) and Huntington’s disease (HD) have been extensively studied and recently been used for the production of xenografts that are already in clinical trials. [13] Advances in swine genomics have resulted in the development of transgenic swine models of several other neurodegenerative diseases including HD, Alzheimer’s disease (AD), and retinitis pigmentosa (RP). The transgenic swine HD model expresses mutant swine huntington protein (HTT) while the AD model expresses mutant human amyloid precursor protein (APP). Neither of these models have yet been fully characterized as functional deficits will only appear as the animals age. The transgenic swine RP model expresses mutant swine rhodopsin protein (RHO) and as a result is afflicted, like humans, with early and near complete degeneration of rod photoreceptors followed by a more protracted deterioration of cone photoreceptors. [2]

References

1.Swindle, M.M. et al. (2011) Swine as models in biomedical research and toxicology testing. Vet. Pathol. [Epub ahead of print, Mar 25].

2.Aigner, B. et al. (2010) Transgenic pigs as models for translational biomedical research. J. Mol. Med. 88:653-664.

3.Lunney, J.K. (2007) Advances in swine biomedical model genomics. Int. J. Biol. Sci. 3:179-184.

4.Dixon, J.A. and Spinale, F.G. (2009) Large animal models of heart failure: a critical link in the translation of basic science to clinical practice. Circ. Heart Fail. 2(3):262-271.

5.Heusch, G. et al. (2011) The in-situ pig heart with regional ischemia/reperfusion – ready for translation. J. Mol. Cell. Cardiol. [Epub ahead of print, Mar 5].

6.hu, K.Q. et al. (2007) Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring. Wound Repair Regen. 15(Suppl. 1):S32-S39.

7.Gomez-Raya, L. et al. (2007) Modeling inheritance of malignant melanoma with DNA markers in Sinclair swine. Genetics 176(1):585-597.

8.Rambow, F. et al. (2008) Gene expression signature for spontaneous cancer regression in melanoma pigs. Neoplasia 10(7):714-726.

9.Lee, P.Y. et al. (2010) Proteomic analysis of pancreata from mini-pigs treated with straptozotocin as type I diabetes models. J. Microbiol. Biotechnol. 20(4):817-820.

10.Rogers, C.S. et al. (2008) The porcine lung as a potential model for cystic fibrosis. Am. J. Physiol. Lung Cell. Mol. Physiol. 295:L240-L263.

11.Naim, M.Y. et al. (2010) Folic acid enhances early functional recovery in a piglet model of pediatric head injury. Dev. Neurosci. 32:466-479.

12.Kuluz, J.W. et al. (2007) New pediatric model of ischemic stroke in infant piglets by photothrombosis – acute changes in cerebral blood flow, microvasculature, and early histopathology. Stroke 38:1932-1937.

13.Wakeman, D.R. (2006) Large animal models are critical for rationally advancing regenerative therapies. Regen. Med. 1(4):405-413.

Swine as an Animal Model... for Cystic Fibrosis

2011-09-01T08:18:00.000-05:00

Cystic fibrosis (CF) is an autosomal recessive disease resulting from a variety of mutations in the cftr gene, which codes for the cystic fibrosis transmembrane conductance regulator anion channel. The disease dramatically affects multiple organs, but the main cause morbidity and mortality in humans is failure of the lungs as a result of chronic inflammation and secondary infection. Despite intensive study, available therapies for CF are inadequate and the disease still has no cure. One of the main obstacles in CF research has been the lack of good animal models as mice expressing defective cftr genes fail to develop lung disease. In search of a better model in which to study CF pathogenesis and potential therapeutics, researchers have recently been focusing on swine. [2,10]

Swine have a lifespan amenable to the study of a disease like CF where lung deterioration progresses over a relatively long period of time and potential novel therapeutics would need to be tested over time as well. In contrast to mice, swine lungs are anatomically, physiologically, histologically, and biochemically very similar to human lungs. Further, swine have already been established as reliable animal models for a variety of lung-related studies including lung development, injury (hypoxia-, toxin-, or reperfusion-induced), growth after lobectomy, transplantation, airway hyper-responsiveness, asthma, surfactant biology, and many other aspects of lung pathophysiology. [10]

Transgenic swine bearing mutations in the cftr gene have recently been innovated and characterized as developing lung disease that very closely approximates clinical observations. Wild-type human and swine CFTR proteins display 93% identical amino acid sequences that are translated in the endoplasmic reticulum (ER), glycosylated in the Golgi, and transported to the apical membrane of airway epithelia where they function as anion channels controlled by phosphorylation. While human mutant CFTR protein is nearly completely retained within the ER and degraded, a very small portion of swine mutant CFTR escapes and can be detected on the apical membrane. Despite this low level CFTR presence, swine expressing mutant CFTR show aberrant airway epithelial electrolyte transport similar to humans. [10]

The lungs of patients suffering from CF easily become infected by a wide variety of pathogens and though humans and swine are not susceptible to precisely the same subset of viral or bacterial species, the resulting immune response and chronic inflammatory state that ensues is very comparable. Swine possess airway host defense mechanisms that are notably similar to humans including resident phagocytes expressing the full complement of pattern recognition receptors, soluble bioactive peptides and proteins including defensins, collectins, and others, and a wide variety of pro-inflammatory cytokines, chemokines, and their respective receptors. How CFTR dysfunction adversely affects host defense making sufferers more susceptible to infection is not known, but increasing ionic strength of human and swine airway surface liquid is known to reduce its antimicrobial capability. [10]

References

1.Swindle, M.M. et al. (2011) Swine as models in biomedical research and toxicology testing. Vet. Pathol. [Epub ahead of print, Mar 25].

2.Aigner, B. et al. (2010) Transgenic pigs as models for translational biomedical research. J. Mol. Med. 88:653-664.

3.Lunney, J.K. (2007) Advances in swine biomedical model genomics. Int. J. Biol. Sci. 3:179-184.

4.Dixon, J.A. and Spinale, F.G. (2009) Large animal models of heart failure: a critical link in the translation of basic science to clinical practice. Circ. Heart Fail. 2(3):262-271.

5.Heusch, G. et al. (2011) The in-situ pig heart with regional ischemia/reperfusion – ready for translation. J. Mol. Cell. Cardiol. [Epub ahead of print, Mar 5].

6.hu, K.Q. et al. (2007) Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring. Wound Repair Regen. 15(Suppl. 1):S32-S39.

7.Gomez-Raya, L. et al. (2007) Modeling inheritance of malignant melanoma with DNA markers in Sinclair swine. Genetics 176(1):585-597.

8.Rambow, F. et al. (2008) Gene expression signature for spontaneous cancer regression in melanoma pigs. Neoplasia 10(7):714-726.

9.Lee, P.Y. et al. (2010) Proteomic analysis of pancreata from mini-pigs treated with straptozotocin as type I diabetes models. J. Microbiol. Biotechnol. 20(4):817-820.

10.Rogers, C.S. et al. (2008) The porcine lung as a potential model for cystic fibrosis. Am. J. Physiol. Lung Cell. Mol. Physiol. 295:L240-L263.

11.Naim, M.Y. et al. (2010) Folic acid enhances early functional recovery in a piglet model of pediatric head injury. Dev. Neurosci. 32:466-479.

12.Kuluz, J.W. et al. (2007) New pediatric model of ischemic stroke in infant piglets by photothrombosis – acute changes in cerebral blood flow, microvasculature, and early histopathology. Stroke 38:1932-1937.

13.Wakeman, D.R. (2006) Large animal models are critical for rationally advancing regenerative therapies. Regen. Med. 1(4):405-413.

Swine as an Animal Model for Diabetes - part 4

2011-07-10T13:12:00.000-05:00

While mainstream models of diabetes research remain rodents, there has been an increasing need for translational research in large animal models of the disease. Swine have many similarities to humans that make them a good choice for modeling diabetes including an omnivorous diet, gastrointestinal tract anatomy and physiology, general metabolic status, and pancreatic size, shape, and position (particular in minipigs). Further, the fact that swine are closer to humans phylogenetically, as evidenced by swine and human insulin polypeptides differing by only one amino acid, is important when interpreting data or translating results to clinical applications. Another advantage of the swine model is their similar pharmacokinetics with respect to subcutaneously administered drugs. [2,9]

Swine models of type 1 diabetes (T1D), type 2 diabetes (T2D), and maturity-onset diabetes of the young type 3 (MODY3) have been developed. The swine T1D model is created by administering streptozotocin (STZ) to intact animals. STZ is preferentially lethal to the insulin-secreting β-cells in pancreatic islets of Langerhans and STZ-treated swine display a human-like diabetic phenotype as evidenced by their significantly increased blood glucose levels after both intravenous and oral glucose delivery. This model has been used for a variety of investigations into T1D pathology including recent proteomics studies that implicate several proteins as potential target candidates for further analysis. [9] Models of T2D include a new transgenic swine line in which pancreatic β-cells express a dominant negative mutant human gipr transgene. Discovery studies in mice have implicated glucose-dependent insulinotropic polypeptide (GIP) and its receptor (GIPR) in T2D pathogenesis. Normally, lipid- or glucose-induced GIP secretion from enteroendocrine cells promotes glucose-mediated insulin release. However, in T2D patients, GIP and/or GIPR are functionally impaired resulting in poor insulin response to oral glucose. Transgenic GIPR^dn swine display deficits in oral, but not intravenous, glucose tolerance resulting from poor insulin secretion at 11 weeks of age. By 5 months, these animals additionally displayed a marked reduction in total β-cell volume and by 11 months, intravenous glucose tolerance is also significantly impaired. These results confirm that GIP/GIPR are critically involved in the maintenance of β-cell health in vivo and thus further promote their status as potential T2D therapeutic targets. [2] A transgenic swine model of MODY3 has been developed in which a dominant negative mutation in the human hepatocyte nuclear factor 1α (HNF1A) transgene is expressed. Like GIPR, HNF1A was first identified as a candidate target in mouse. While most transgenic HNF1A^dn piglets died shortly after birth, those that survived displayed elevated non-fasting blood glucose levels and transgenic protein expression in the pancreas and kidney. Upon closer examination, malformation of pancreatic islet structures and glomerular hypertrophy and sclerosis of the kidneys is evident. [2]

References

1. Swindle, M.M. et al. (2011) Swine as models in biomedical research and toxicology testing. Vet. Pathol. [Epub ahead of print, Mar 25].

2. Aigner, B. et al. (2010) Transgenic pigs as models for translational biomedical research. J. Mol. Med. 88:653-664.

3. Lunney, J.K. (2007) Advances in swine biomedical model genomics. Int. J. Biol. Sci. 3:179-184.

4. Dixon, J.A. and Spinale, F.G. (2009) Large animal models of heart failure: a critical link in the translation of basic science to clinical practice. Circ. Heart Fail. 2(3):262-271.

5. Heusch, G. et al. (2011) The in-situ pig heart with regional ischemia/reperfusion – ready for translation. J. Mol. Cell. Cardiol. [Epub ahead of print, Mar 5].

6. hu, K.Q. et al. (2007) Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring. Wound Repair Regen. 15(Suppl. 1):S32-S39.

7. Gomez-Raya, L. et al. (2007) Modeling inheritance of malignant melanoma with DNA markers in Sinclair swine. Genetics 176(1):585-597.

8. Rambow, F. et al. (2008) Gene expression signature for spontaneous cancer regression in melanoma pigs. Neoplasia 10(7):714-726.

9. Lee, P.Y. et al. (2010) Proteomic analysis of pancreata from mini-pigs treated with straptozotocin as type I diabetes models. J. Microbiol. Biotechnol. 20(4):817-820.

10. Rogers, C.S. et al. (2008) The porcine lung as a potential model for cystic fibrosis. Am. J. Physiol. Lung Cell. Mol. Physiol. 295:L240-L263.

11. Naim, M.Y. et al. (2010) Folic acid enhances early functional recovery in a piglet model of pediatric head injury. Dev. Neurosci. 32:466-479.

12. Kuluz, J.W. et al. (2007) New pediatric model of ischemic stroke in infant piglets by photothrombosis – acute changes in cerebral blood flow, microvasculature, and early histopathology. Stroke 38:1932-1937.

13. Wakeman, D.R. (2006) Large animal models are critical for rationally advancing regenerative therapies. Regen. Med. 1(4):405-413.

Swine as an Animal Model for Wound Healing & Melanoma - part 3

2011-06-10T20:25:00.000-05:00

Swine skin is remarkably similar to human skin and as such has become a standard model for reconstructive and plastic surgery and wound healing. Anatomically, swine skin is largely hairless, has a thick epidermal layer, a fixed subcutaneous layer, and a human-like pattern of cutaneous blood supply. Physiologically, swine skin responds as human skin does to various growth factors and cytokines and displays a wound healing process, similar to that documented in humans, in which re-epithelialization rather than contraction occurs. Swine skin has been used in the development of skin surgical techniques, laser therapy, and burn care and the study of dermatological conditions including vitiligo, dry skin, aseptic necrosis, hypertrophic scarring, melanoma, and others. [1,6]

Burn injury results in hypertrophic scarring (HS), which produces permanent hard, red, raised scars that are painful, disfiguring, and often debilitating. Despite decades of research, there is still very little known about the pathophysiology of HS and no treatments are available. Experimental models have been attempted using mice, rats, rabbits, dogs, and cats, but have been abandoned due to their failure to mimic human HS. By contrast, swine appear to produce scarring most similar to human HS as measured by clinical and histological appearance, biomarker presence, and nerve fiber, mast cell, and myofibroblast populations. The swine model of human HS is not perfect, but currently presents the best overall approximate for studies of burn wound healing and scarring available. [6]

Cutaneous malignant melanoma is very aggressive and infamously resistant to chemotherapy, radiotherapy, and immunotherapy strategies. Partial spontaneous regression is observed in some forms of human melanoma, but only rarely does complete regression occur. By contrast, swine spontaneously develop melanoma analogous to that observed in humans that very frequently regresses completely. The Sinclair swine cutaneous melanoma (SSCM) model and the melanoma-bearing Libechov minipig (MeLiM) model have been developed and characterized in the hope of discovering genes that can be identified as susceptibility loci for heritable melanoma or associated with the cellular and molecular mechanisms involved in melanoma regression. [3,7,8] Genetic variability in four genes are already known to account for 50% of human familial malignant melanoma (FMM) cases. Further work on this issue is being performed using computer-assisted mathematical modeling using the SSCM model in the hope of identifying these and other candidate loci involved in the initiation, progression, and aggressiveness of FMM in swine. In this case the SSCM model provides advantages over similar familial studies in humans because of the short gestation times and high progeny numbers achievable with swine. [7] In the MeLiM swine model, tumors naturally regress with a frequency of 96% and are observed to become more flat, dry, depigmented, and infiltrated with leukocytes as they regress. Analysis of the swine transcriptome during tumor regression has identified a pool of approximately 1,400 genes that are differentially expressed during this process. Though obviously further review of each of these genes will be required, some interesting general trends are apparent. For example, genes involved in cell cycle and DNA replication and repair are down-regulated early in regression suggesting retardation of melanoma cell proliferation. Additionally, genes associated with monocytes/macrophages are up-regulated at intermediate time points during regression suggesting that tumors do not evade immune attack in swine. [8]

References
6. Zhu, K.Q. et al. (2007) Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring. Wound Repair Regen. 15(Suppl. 1):S32-S39.

7. Gomez-Raya, L. et al. (2007) Modeling inheritance of malignant melanoma with DNA markers in Sinclair swine. Genetics 176(1):585-597.

8. Rambow, F. et al. (2008) Gene expression signature for spontaneous cancer regression in melanoma pigs. Neoplasia 10(7):714-726.

Swine as an Animal Model for Cardiovascular Disease - part 2

2011-06-08T15:04:00.000-05:00

The swine heart is particularly suited to the study of human cardiovascular disease as its gross anatomy is very similar and its coronary microvasculature is nearly identical to that of humans – blood supply to the heart is right-side dominant and lacking in pre-existing collateral vessels. Physiologically, swine resting heart rates and left ventricular (LV) pressures are comparable to humans. Experimentally, swine offer advantages over smaller animal models of cardiovascular disease simply because of their larger size. For example, swine can tolerate multiple biopsies from the same tissues, intracoronary drug delivery, and implantation of microdialysis probes. [4,5] Swine have been used in the development and testing of intravascular stents, aneurysm surgery, valve replacement, cardiac transplant, and cardiac assist devices. [1] They have also served as important pre-clinical models for testing of new pharmacological agents and more recently stem cell therapy and gene therapy. Stem cells administered to swine post-myocardial infarction (MI) have been shown to decrease MI expansion and improve LV ejection fraction and gene therapy results using a swine model of heart failure (HF) have proved so effective that clinical trials have already begun. [4]

Swine also function as important models of MI, ischemia reperfusion (IR) injury, HF, and dilated cardiomyopathy (DCM). One of the main advantages of the use of swine as a model of cardiovascular disease is the ease with which MI can be produced in predictable sizes and locations analogous to MI in humans. Thus, swine are commonly used in pre-clinical studies investigating new strategies for limiting IR injury, infarct expansion, and LV remodeling. Post-MI, swine are positively affected by all of the cardioprotective strategies currently available for humans including hibernation and ischemic pre- and post-conditioning. Swine HF closely mimics that of humans in many respects as LV functions is depressed (i.e., myocyte contractility is impaired and ejection fraction is reduced) and the neurohormonal axis is activated. Additionally, DCM brought on by pacing-induced tachycardia in swine approximates the human DCM phenotype as it results in LV dilation, pump dysfunction, and neurohormonal changes similar to clinical observations. [4,5]

4. Dixon, J.A. and Spinale, F.G. (2009) Large animal models of heart failure: a critical link in the translation of basic science to clinical practice. Circ. Heart Fail. 2(3):262-271.
5. Heusch, G. et al. (2011) The in-situ pig heart with regional ischemia/reperfusion – ready for translation. J. Mol. Cell. Cardiol. [Epub ahead of print, Mar 5].

IL-8 Homology Between Species

2011-05-22T15:09:00.002-05:00

The primary function of IL-8 is to recruit neutrophils to sites of inflammation. IL-8 is approximately 75 amino acids plus or minus 5 amino acids in all species compared. Although small, the percent homology varies from the high 80's between sheep, cows, and dogs and as low as 60% between guinea pigs and horses. Kingfisher Biotech has an expanding portfolio of IL-8 proteins, antibodies and ELISA Kits across many species.

Swine as an Animal Model for Human Disease - part 1

2011-05-21T20:46:00.003-05:00

Of the large animal species used for biomedical research, swine is easily the most popular. There are hundreds of breeds available worldwide, some of which are classified as miniature swine and commonly known as minipigs. Swine reach sexual maturity early, breed year-round, and deliver as many as 10 to 12 piglets in a single litter. Swine are large enough and robust enough to tolerate complex experimental protocols over an extended period of time that require multiple interventions, repeated tissue or fluid sampling, and imaging using technologies standard to hospitals. There is broad availability of a range of established cell lines derived from a variety of swine tissues and the offering of swine-specific reagents is expanding. Preliminary data from the swine genome project confirms the phylogenetic status of swine as closer to humans than rodent species, lending further weight to the selection of swine as a model for biomedical research. Further, swine genomics and proteomics are more advanced than nearly every other large animal model. [1-3]

It is of course most important, when selecting a model for biomedical research, that the model closely approximate the human condition under study. In this case as well, swine has enormous advantages over small mammal or invertebrate model systems. Swine are very similar to humans in various aspects of their anatomy and physiology, diet and metabolism, and histopathology and pharmacokinetics. [1-3] Over the years, swine have been used to model so many different aspects of human physiology and pathology that it would be impossible to mention them all here. Thus, this summary should be taken as neither comprehensive nor definitive, rather as an overview of some of the more prominent fields in which swine serve as important models. We will cover swine as a model for cardiovascular disease, wound healing and melanoma, diabetes, cystic fibrosis, and traumatic brain injury, stroke, and neurodegenerative disease.

References

1. Swindle, M.M. et al. (2011) Swine as models in biomedical research and toxicology testing. Vet. Pathol. [Epub ahead of print, Mar 25].
2. Aigner, B. et al. (2010) Transgenic pigs as models for translational biomedical research. J. Mol. Med. 88:653-664.
3. Lunney, J.K. (2007) Advances in swine biomedical model genomics. Int. J. Biol. Sci. 3:179-184.

Equine IFN gamma ELISA Development Kit (VetSet)

2011-03-05T18:44:00.010-06:00

With a range of 0.6-38 ng/mL and two coated plates, you can measure 80 samples in duplicate with ease and reproducibility with the Equine IFN gamma VetSet.

Feline and Canine SCF Bioactivity Data

2010-11-17T22:06:00.001-06:00

IL-1 beta Percent Homology

2010-08-22T15:11:00.003-05:00

The homology of IL-1 beta was evaluated across 10 species (bovine, canine, chicken, equine, feline, human, mouse, rabbit, swine, and turkey). It ranged from 31.6% - 93.9% with the highest homology seen between chicken and turkey. When comparing mammals, the highest homology was seen between rabbit and mouse (81.5%), followed closely by rabbit and human (81.0%).

IFN gamma Homology Across Species

2010-08-10T10:54:00.004-05:00

The homology of mature IFN gamma across 8 species was evaluated. Equine and Bovine IFN gamma exhibited the highest homology (80.4%). Equine and Bovine IFN gamma also looked similar on SDS-PAGE gel analysis. The homology between human and mouse IFN gamma and the other species is quite low. This information gives further credence for species-specific bioassays.

Comparison of IFN gamma Across Five Species

2010-08-09T14:14:00.002-05:00

The SDS-PAGE gel compares bovine, feline, equine, rabbit, and swine IFN gamma proteins. The proteins were all expressed in yeast so post-translational modifications are present. Although the unmodified forms of the proteins are calculated to be similar, it is obvious that there are differences between species, which may account for the species specificity that is commonly noted in the scientific literature.

Bovine, Equine, and Swine CCL2

2010-07-22T13:46:00.003-05:00

Chemokine (C-C motif) ligand 2 (CCL2) is a small cytokine belonging to the CC chemokine family that is also known as monocyte chemotactic protein-1 (MCP-1). CCL2 recruits monocytes, memory T cells, and dendritic cells to sites of tissue injury and infection.

Bovine, Canine, Equine IL-5 Activity

2010-07-06T10:44:00.005-05:00

Bovine, Canine, and Equine IL-5 are all active using the TF-1 cell proliferation bioassay. IL-5 activates eosinophils and stimulates B cell growth.

IL-2 Activity Data

2010-07-06T10:19:00.006-05:00

Activity results are back on our canine, feline, and rabbit IL-2 proteins - all are active. IL-2 is an important cytokine involved in T cell development and immune responses.

The CTLL-2 cell line proliferates in response to IL-2.

Bovine and Swine IFN gamma

2010-02-14T16:20:00.005-06:00

Recombinant bovine (left) and swine (right) IFN gamma exhibited two major protein bands, one at approximately 16.9/16.8 kDa (predicted MW) and one larger protein band at approximately 22 kDa (molecular weight markers starting from bottom 7.8, 12, 22 kDa). The larger MW protein most likely represents posttranslationally modified IFN gamma. Pichia pastoris is known to provide posttranslational modifications to secreted proteins.

IFN gamma is a cytokine that is critical for innate and adaptive immunity against viral and intracellular bacterial infections and for tumor control. Aberrant IFN gamma expression is associated with a number of autoinflammatory and autoimmune diseases.

Feline IL-2 VetSet (ELISA Development Kit)

2010-02-01T14:48:00.006-06:00

This kit is for the quantitative measurement of Feline IL-2 in cell culture supernatants.

PBMCs harvested by ficoll density gradient from an apparently healthy feline were suspended in RPMI medium containing 10% fetal bovine serum and stimulated as desired. The cell-free supernatants were harvested following two days stimulation and analyzed in the Feline IL-2 VetSet ELISA Development Kit.

Stimulant -- Feline IL-2 (ng/ml)
Unstimulated -- <50
PHA; 10 µg/ml -- <50
Staphylococcal enterotoxin B; 5 µg/ml -- <50
PMA; 10 ng/ml & Inomycin; 500 ng/ml -- 160

Bovine and Swine CXCL11

2010-02-01T10:54:00.003-06:00

Recombinant bovine (left) and porcine (right) CXCL11 exhibited two major protein bands, one at approximately 9 kDa (predicted MW) and one larger protein band at approximately 13 kDa (molecular weight markers starting from bottom 7.8, 12, 22 kDa). The larger MW protein most likely represents posttranslationally modified CXCL11. Recombinant equine CXCL11 exhibited the same protein band pattern, which is unique to the CXCL11 proteins. Pichia pastoris is known to provide posttranslational modifications to secreted proteins.

Bioactivity of Feline, Canine, and Equine IL-1 beta

2010-01-06T10:00:00.003-06:00

The biological activity of recombinant canine, feline and equine
IL-1 beta was determined in a cell proliferation assay using the
mouse T-helper cell line D10S.

Recombinant Canine IL-8

2009-10-14T13:15:00.002-05:00

The protein encoded by the IL-8 gene is a member of the CXC chemokine family. This chemokine is one of the major mediators of the inflammatory response. This chemokine is secreted by several cell types. It functions as a chemoattractant, and is also a potent angiogenic factor. Both monomer and homodimer forms of IL-8 were reported as potent inducers of CXCR1 and CXCR2, the homodimer proved to be more potent, however, methylation of Leu25 can block activity of the dimers. In humans, IL-8 is believed to play a role in the pathogenesis of bronchiolitis, a common respiratory tract disease caused by viral infection. This gene and other ten members of the CXC chemokine gene family form a chemokine gene cluster in a region mapped to chromosome 4q.
Primary function of IL-8 is the induction of chemotaxis in its target cells (e.g. neutrophil granulocytes). In neutrophils series of cell-physiological responses required for migration and its target function phagocytosis are also induced like increase of intracellular Ca2+, exocytosis (e.g. histamine release), respiratory burst. IL-8 can be secreted by any cells with toll-like receptors which are involved in the innate immune response. IL-8's primary function is to recruit neutrophils to phagocytose the antigen which trigger the antigen pattern toll-like receptors.
When first encountering an antigen, the primary cells to encounter it are the macrophages who phagocytose the particle. Upon processing, they release chemokines to signal other immune cells to come in to the site of inflammation. IL-8 is one such chemokine. It serves as a chemical signal that attracts neutrophils at the site of inflammation, and therefore is also known as neutrophil chemotactic factor.

Swine TNF alpha

2009-10-07T12:20:00.003-05:00

Tumor necrosis factor (TNF, cachexin or cachectin and formally known as tumor necrosis factor-alpha) is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction. The primary role of TNF is in the regulation of immune cells. TNF is also able to induce apoptotic cell death, to induce inflammation, and to inhibit tumorigenesis and viral replication. Dysregulation and, in particular, overproduction of TNF have been implicated in a variety of human diseases, as well as cancer.

Kingfisher Biotech offers Recombinant Swine TNF alpha in both 5 ug and 25 ug. The monomer has a predicted molecular weight of 16.9 kDa.

Recombinant Feline IL-8

2009-10-06T09:54:00.000-05:00

Feline IL-8 is a a 8.9 kDa protein (79 amino acids). The gel shows a nice clean crisp band between the 7.8 and 12 kDa markers. IL-8 is a member of the CXC chemokine family.

Chicken IL-16 VetSet

2009-09-29T16:55:00.002-05:00

Kingfisher Biotech now has an ELISA Development kit available for Chicken IL-16 (cat# VS0082C-002). The kit contains two coated plates, chicken IL-16 standard, detection antibody and streptavidin-HRP. It is for the measurement of chicken IL-16 in cell culture supernatants.

Recombinant Feline IL-2

2009-09-17T13:45:00.005-05:00

Recombinant Feline IL-2 is now available from Kingfisher Biotech. Interleukin-2 (IL-2) is a cytokine produced by T-helper cells in response to antigenic or mitogenic stimulation. This protein is required for T-cell proliferation and other activities crucial to the regulation of the immune response. Feline IL-2 has an approximate molecular weight of 15.4 kDa.

Bovine IL-1F5

2009-08-26T16:07:00.004-05:00

Bovine IL-1F5 is a member of the IL-1 superfamily. In humans, this family includes IL-1 alpha, IL-1 beta, IL-1 receptor antagonist, IL-18, IL-33, and IL-1F5-IL-1F10. Bovine IL-1F5 has a predicted molecular weight of 17.1 kDa. Recombinant Bovine IL-1F5 is now availalbe from Kingfisher Biotech in two sizes - 5 ug and 25 ug.

Bovine IL-1 alpha

2009-08-13T13:24:00.004-05:00

Recombinant Bovine IL-1α (IL-1 alpha) is now available from Kingfisher Biotech in 2 sizes - 5 ug and 25 ug. IL-1α and -β are pro-inflammatory cytokines involved in immune defense against infection.

11 New Antibodies for Veterinary Research

2009-08-06T17:47:00.004-05:00

Anti-chicken IL-16 PAb
Host - Goat
PB0086C-100
Applications - ELISA, Western Blot

Biotinylated Anti-chicken IL-16 PAb
Host - Goat
PBB0087C-050
Applications - ELISA, Western Blot

Anti-swine CCL2 PAb
Host - Goat
PB0088S-100
Applications - ELISA, Western Blot

Biotinylated Anti-swine CCL2 PAb
Host - Goat
PBB0089S-050
Applications - ELISA, Western Blot

Anti-bovine CCL2 PAb
Host - Goat
PB0090B-100
Applications - ELISA, Western Blot

Biotinylated Anti-bovine CCL2 PAb
Host - Goat
PBB0091B-050
Applications - ELISA, Western Blot

Anti-bovine CCL2 PAb
Host - Rabbit
PB0092B-100
Applications - ELISA, Western Blot

Biotinylated Anti-bovine CCL2 PAb
Host - Rabbit
PBB0093B-050
Applications - ELISA, Western Blot

Anti-swine IL-13 PAb
Host - Goat
PB0094S-100
Application - ELISA

Anti-swine IL-13 PAb
Host - Goat
PB0095S-100
Applications - ELISA, Western Blot

Biotinylated Anti-swine IL-13 PAb
Host - Goat
PBB0096S-050
Applications - ELISA, Western Blot

Canine IL-1 beta

2009-07-30T14:51:00.010-05:00

Canine IL-1β (IL-1 beta) is now available from Kingfisher Biotech. It has an approximate molecular weight of 17.5 kDa. IL-1β is produced by macrophages, monocytes and dendritic cells. It forms an important part of the inflammatory response of the body against infection. IL-1β increases the expression of adhesion factors on endothelial cells to enable transmigration of leukocytes, the cells that fight pathogens, to sites of infection and re-set the hypothalamus thermoregulatory center, leading to an increased body temperature which expresses itself as fever.

Swine CCL3L1

2009-05-20T18:38:00.003-05:00

Chemokine (C-C motif) ligand 3-like 1 (aka CCL3L1 and LD78) is a chemokine belonging to the CC Chemiokine family. CC chemokines induce the migration of monocytes and other cell types such as NK cells and dendritic cells. Swine CCL3L1 has an approximate molecular weight of 7.8 kDa.

Swine, Bovine, and Equine CCL5

2009-04-22T12:50:00.001-05:00

Recombinant Swine, Bovine, and Equine CCL5 (RANTES) are now available from Kingfisher Biotech. CCL5 is an 8kDa protein classified as a chemotactic cytokine or chemokine. CCL5 is chemotactic for T cells, eosinophils, and basophils, and plays an active role in recruiting leukocytes into inflammatory sites. With the help of particular cytokines (i.e., IL-2 and IFN-γ) that are released by T cells, CCL5 also induces the proliferation and activation of certain natural-killer (NK) cells to form CHAK (CC-Chemokine-activated killer) cells. It is also an HIV-suppressive factor released from CD8+ T cells. This chemokine has been localized to chromosome 17 in humans. RANTES was first identified in a search for genes expressed "late" (3-5 days) after T cell activation. It was subsequently determined to be a CC chemokine and expressed in more than 100 human diseases. RANTES expression is regulated in T lymphocytes by Kruppel like factor 13 (KLF13).

Swine CCL4

2009-04-16T16:42:00.002-05:00

Swine CCL4 (MIP-1 beta) is now available. Other Swine Chemokines include, CCL2 (MCP-1), CCL5 (RANTES), CXCL10 (IP-10), and CXCL11 (I-TAC). Check out these as well as many other recombinant proteins and antibodies at www.kingfisherbiotech.com.

Kingfisher Biotech on Twitter

2009-04-10T19:30:00.003-05:00

Watch for online specials of Kingfisher Biotech products each Monday on Twitter (http://twitter.com/kingfisherbio).

Equine Chemokines

2009-04-08T16:50:00.002-05:00

Recombinant Equine CCL2 (MCP-1), CCL3 (MIP-1 alpha), CCL11 (Eotaxin), CXCL9 (MIG), and CXCL10 (IP-10) are now available from Kingfisher Biotech. All five proteins were produced in yeast so they mimic the natural protein.

Chemokines are a family of small cytokines, or proteins secreted by cells. Proteins are classified as chemokines according to shared structural characteristics such as small size (they are all approximately 8-10 kilodaltons in size), and the presence of four cysteine residues in conserved locations that are key to forming their 3-dimensional shape. Their name is derived from their ability to induce directed chemotaxis in nearby responsive cells; they are chemotactic cytokines.

Recombinant Equine IL-1 beta

2009-03-30T16:48:00.002-05:00

Recombinant Equine IL-1 beta (a.k.a. IL1F2) makes nine recombinant equine proteins available from Kingfisher Biotech. IL-1 beta is is a member of the IL-1 superfamily.

Chicken Chemokines

2009-03-23T17:28:00.002-05:00

Recombinant chicken CCL4 (a.k.a. MIP-1 beta) and CCL20 (a.k.a. LARC) are now available from Kingfisher Biotech (www.kingfisherbiotech.com). Both proteins are members of the CC chemokine family. CC chemokines induce the migration of monocytes and other cell types such as NK cells and dendritic cells. An example of a CC chemokine is monocyte chemoattractant protein-1 (MCP-1 or CCL2) which induces monocytes to leave the bloodstream and enter the surrounding tissue to become tissue macrophages. CC chemokines induce cellular migration by binding to and activating CC chemokine receptors, ten of which have been discovered to date and called CCR1-10. These receptors are expressed on the surface of different cell types allowing their specific attraction by the chemokines. A CC chemokine that attracts lymphocytes is CCL28, which is chemoattractant to T cells and B cells that express the chemokine receptor CCR10. This chemokine can also attract eosinophils that express CCR3. CCL5 (or RANTES) attracts cells such as T cells, eosinophils and basophils that express the receptor CCR5.

Equine CXCL9 and CXCL10

2009-02-23T16:45:00.002-06:00

A horse is a horse, of course, of course, and no one can talk to a horse of course. That is, of course, unless the horse is the famous Mister Ed. If you are too young to remember Mr. Ed, don't let me know. I don't want to feel any older than I am.

Recombinant Equine CXCL9 (MIG) and CXCL10 (IP-10) are ready for bioassay. Both proteins are members of the CXC family of chemokines. Since many of our proteins have never been made commercially available and may also be species specific, we are calling out to anyone that has potential bioassays to contact us at info@kingfisherbiotech.com.

Iowa State

2009-02-23T16:39:00.002-06:00

Sorry I have be remiss adding postings to my blog. I visited Iowa State last week. What a beautiful campus with a great history in agriculture. Did you know that Iowa Stge is 150 years old? It was originally called Iowa Agricultural College and Model Farm. If you ever have the chance, it is worth the visit.

CCL2 - Equine, Swine, and Bovine

2009-01-27T17:06:00.001-06:00

Bovine, Equine, and Swine CCL2 are now available (www.kingfisherbiotech.com). Chemokine (C-C motif) ligand 2 (CCL2) is a small cytokine belonging to the CC chemokine family that is also known as monocyte chemotactic protein-1 (MCP-1). CCL2 recruits monocytes, memory T cells, and dendritic cells to sites of tissue injury and infection.

Polyclonal Antibodies to Equine IL-2 and IL-4

2009-01-17T15:12:00.003-06:00

Our first antibodies are tested and ready for you to use in your research. The antibodies are polyclonal antibodies to equine IL-2 and equine IL-4. The anti-equine IL-2 antibody is qualified for Western Blot and ELISA. The anti-equine IL-4 antibody is qualified for Western Blot.

We also have two more proteins ready for bioassay testing - Recombinant Chicken IL-18 and Recombinant Swine IFN beta.

Watch for product details at http://www.kingfisherbiotech.com/.

Chicken IL-10

2009-01-15T19:10:00.002-06:00

Good news. The Recombinant Chicken IL-10 is active. Biological activity of Recombinant Chicken IL-10 was determined by measuring IFN-gamma expression by real-time PCR in Concanavalin A-stimulated chicken spleen lymphocytes. Results demonstrate decreased IFN-gamma gene expression with the addition of recombinant Chicken IL-10, in a dose-dependant manner, with doses starting at 2 ng/mL. Informations will be added to the website within the next day.

What do cows wear in Hawaii?

2009-01-12T23:53:00.001-06:00

Moo-moos, of course! A little humor for a cold January day. Living in Minnesota in January makes us all dream of a Hawaiian vacation.

IL-15 - Bovine, Equine, and Swine

2009-01-06T19:43:00.003-06:00

Bovine, Equine, and Swine IL-15 are now purified. They will all be sent out out for bioassay. We should have results next week. The three proteins are all quite similar in size and pI so the same protocol could be used to purify all three proteins. Watch www.kingfisherbiotech.com for product details.

SDS-PAGE gels

2008-12-26T23:23:00.002-06:00

With all the protein purification taking place in the lab, we run a lot of protein gels. We decided to make the gels available commercially. Gels are available in 8%, 10%, 12%, 16%, 4-8%, 4-12%, 4-20%, and 10-20% in both 12 and 17 well formats. The precast gel technology, buffer formulations and cassette design produce high-performance protein separations in an easy-to-use product.

Recombinant Equine IL-15

2008-12-23T10:57:00.000-06:00

December is finishing up on a high note at Kingfisher Biotech (http://www.kingfisherbiotech.com/). This month, five new proteins for veterinary research have been successfully purified and are being tested for bioactivity - Bovine CCL2, Bovine CXCL9, Bovine IL-2, Equine GM-CSF, and Equine IL-15. These efforts to make more tools available for veterinary research are in part supported by a USDA grant. You can learn more about the grant at http://www.vetimm.org/.

Interleukin 15 (IL-15) is a cytokine with structural similarity to IL-2 that is secreted by mononuclear phagocytes (and some other cells) following infection by virus(es). This cytokine induces cell proliferation of natural killer cells; cells of the innate immune system whose principal role is to kill virally infected cells, making it an important molecule to have available for equine research. We successfully purified recombinant equine IL-15 from yeast and will send it out for bioassay in the next week. You can find all the details about our equine Il-15 protein at http://www.kingfisherbiotech.com/.

Equine GM-CSF

2008-12-17T12:50:00.000-06:00

Equine GM-CSF (granulocyte macrophage colony-stimulating factor) is a 15.2 kDa protein. It is produced by several different cell types, including T cells (activated), B cells, macrophages, mast cells, endothelial cells and fibroblasts. It is glycosylated in its mature form. Recombinant Equine GM-CSF, produced in yeast, is now commercially available from Kingfisher Biotech - www.kingfisherbiotech.com.

Recombinant Bovine CCL2 (MCP-1)

2008-12-11T21:02:00.000-06:00

We have been on a roll purifying recombinant bovine proteins. This week, we purified Bovine CCL-2 (MCP-1). It will be made commercially available in the coming weeks. Watch www.kingfisherbiotech.com for product specifications as they become available.

Bovine IL-2 and Bovine CXCL9

2008-12-04T19:17:00.000-06:00

It has been a good week for purifications. Recombinant Bovine CXCL9 and Recombinant Bovine IL-2 were successfully purified. They will be aliquoted and sent for bioassay testing within the next week. Product specifications will be available at http://www.kingfisherbiotech.com/.

Bovine IL-6 Update

2008-11-30T21:09:00.000-06:00

Did you know that bovine IL-6 appears to be species-specific? We have tried to bioassay our recombinant bovine IL-6 protein on both human and mouse cell lines, but it seems that bovine IL-6 does not make mouse or human cells proliferate. We have no reason to believe our protein is not active so we are working on developing a bioassay that uses bovine cells. I will keep you updated.

Anticipation...

2008-11-30T20:34:00.000-06:00

We are starting December quite excited about the prospects of launching our first antibodies. We have several antigen-affinity purifiecd antibodies that will be availabe the second week of December. Watch our website at http://www.kingfisherbiotech.com/ for product specifications. Antigen affinity purification means that the antibodies will we 10X more specific that antibodies purified via protein A or G.

In the beginning...

2008-11-09T11:12:00.001-06:00

Kingfisher Biotech is a start-up company dedicated to increasing the number of reagents available for veterinary research. I am Bessie and I will be keeping you up to date with the activities of the lab.