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ILAR Journal V35(2) 1993 [FORMERLY ILAR NEWS]
Models of Type I Diabetes - Part Two
Diabetes-Prone and Diabetes-Resistant BB Rats: Animal Models of Spontaneous and Virally Induced Diabetes Mellitus, Lymphocytic Thyroiditis, and Collagen-Induced Arthritis
Dennis L. Guberski
| Mr. Guberski is the BB/Wor project administrator at the University of Massachusetts Medical Center in Worcester. |
INTRODUCTION
In 1974, some rats (subsequently called BB) that spontaneously developed autoimmune diabetes mellitus were found in a closed colony of outbred WI (Wistar) rats at the Bio-Breeding Laboratories, Ottawa, Ontario. Since the first report by Nakhooda et al. (1977), colonies of BB rats have been established worldwide. The availability of the model enables investigation into fundamental questions concerning the spontaneous etiopathogenesis (Crisá et al., 1992) and virally induced mechanisms (Guberski et al., 1991) of diabetes. Complications of diabetes, including peripheral neuropathy (Greene et al., 1984; Yagihashi and Sima 1985a,b; Sima et al., 1986; Yagihashi et al., 1986; McEwen and Sima, 1987), impotence (Murray et al., 1985a,b), nephropathy (Chakrabarti et al., 1989; Cohen et al., 1987), and retinal changes (Sima et al., 1985; Chakrabarti et al., 1991), are also widely studied in this model.
This paper will provide an overview of the model, describing the development of the inbred rats, features of the diabetic syndrome, the immunopathology and mechanisms of immune suppression and immune modulation, and the interaction Of genetics and the environment, as well as a brief review of recommended husbandry practices.
DEVELOPMENT OF INBRED DIABETIC RATS
In 1977, Butler et al. (1983, 1988, 1990) began inbreeding BB rats at the University of Massachusetts Medical Center (laboratory code Wor) with 300 breeders purchased from the Bio-Breeding Laboratories. In 1983, the National Institutes of Health established the Wor inbred colony as a reference colony.
The first priority was to develop an inbred model with good fecundity and a high incidence of diabetes. Diabetes was defined as positive glycosuria with a blood glucose concentration greater than 250 mg/dl. The incidence of diabetes was determined in breeders held through 150 days of age. Selection of siblings for breeding occurred after the onset of hyperglycemia. In 1978, between the third and fourth generation of inbreeding, an epidemic of Mycoplasma pumonis caused a substantial number of animals to die. As a result, a pathogen-free rodent barrier system was constructed for the colony. During caesarian rederivation, animals from litters with the highest incidence of diabetes were introduced into the barrier. Following the successful rederivation, genetic studies were undertaken to determine the mechanism of inheritance of diabetes. From these studies two groups of animals were produced. The first was comprised of the progeny of diabetic x diabetic matings, from which six diabetes prone (DP) strains were developed. The second was comprised of progeny selected to remain diabetes free, including the BBVB/Wor strain, a direct descendant from the original 300 breeders, and the BBDR/Wor strain derived from DP rats in the fifth generation of inbreeding. Characteristics of the DP and DR strains are listed in Table 1.
Genetic studies showed that a single diabetic x diabetic mating fixed the recessive diabetogenic genes. Subsequent progeny all had the same incidence of diabetes whether they were the offspring of a phenotypically diabetic x nondiabetic mating or a nondiabetic x nondiabetic mating (Butler et al., 1983). This revolutionized the breeding at the Wot facility. Instead of waiting until hyperglycemia occurred and then mating chronically diabetic rats, mating was now possible before the onset of diabetes, which substantially improved production. New selection criteria were also developed, including selecting for animals that developed hyperglycemia at an early age and came from large litters with a high incidence of diabetes. Animals with an early onset of hyperglycemia are difficult to breed (Murray et al., 1985b; Butler et al., 1988, 1990) due to the difficulty of controlling blood glucose in females during pregnancy and lactation and impotence in chronically diabetic males (Murray et al., 1985a,b). Selection criteria that reduces fertility can cause residual heterozygosity and delay the development of fully inbred lines (Hedrich, 1993). Because diabetes reduces productivity in DP rats and the onset of the disease typically occurs during pregnancy or lactation (Figure 1), residual heterozygosity may still be present in the Wor reference colony. Sound management practice requires continuation of sibling matings.
DP strains are designated BBBA/Wor, BBDP/Wor, BBBE/Wor, BBNA/Wor, BBNB/Wor, and BBPA/Wor, and DR strains are designated BBDR/Wor and BBVB/Wor (Table 1). All strains have been inbred for more than 48 generations.
DIABETES IN DP RATS
DP rats develop a cell-mediated autoimmune destruction of the pancreatic b cells, resulting in an abrupt onset of insulin-dependent, ketosis-prone diabetes mellitus. The development of diabetes in DP strains occurs between 60 and 120 days of age in both males and females. The abrupt onset of disease is characterized by weight loss, polyuria, polydipsia, glycosuria, hyperglycemia, hypoinsulinemia, and ketosis. In the absence of exogenous insulin therapy, animals usually die in 4-7 days (Figure 2). The overall incidence of diabetes in DP strains is 86 percent, and the average age of onset is 80 days (Like et al., 1991). This peripubertal onset of diabetes is comparable to the peak onset observed in 12- to 14-year-old humans.
Insulitis
Insulitis is a term coined by Gepts (1965), who described mononuclear infiltration of the islets of Langerhans in the pancreas of a child who died with acute type I diabetes mellitus. DP rats develop an intense mononuclear insulitis that precedes the onset of disease by 2-3 weeks. Insulitis destroys only the pancreatic b cells (Figures 3-4), resulting in an islet devoid of insulin-positive cells (Figure 5); pancreatic alpha, delta, and polypeptide cells are not destroyed. Studies to determine which cells make up the insulitis lesion suggest that different lymphoid populations are present, depending on the stage of insulitis. The initial infiltrate is comprised of ED1+ cells (macrophages/dendritic cells) (Kiesel et al., 1986; Lee et al., 1988). Later, CD4+, CD8+, and natural killer (NK) cells are found. Recently Ellerman et al. (1993) and Shachner et al. (1992) demonstrated that NK cells are not the final effector cells for b-cell destruction. In situ studies have demonstrated the presence of TNF, IL- 1, and IL-6 mRNA in islets of acutely diabetic DP rats (Jiang and Woda, 1991). Pancreatic lymphocytic infiltration (PLI) has also been reported to precede the insulitis lesion (Guttmann et al., 1983). However, PLI can also be found in animals that never become diabetic or demonstrate insulitis (Dr. Arthur A. Like, Personal Communication, University of Massachusetts Medical School, Worcester, Massachusetts).
IMMUNOPATHOLOGY
Lymphopenia
DP strains are severely lymphopenic (Elder and Maclaren, 1983), as manifested by a reduction in T lymphocytes in peripheral blood, spleen, and lymph nodes. Peripheral blood samples obtained from venous sinus punctures, after being sequentially incubated with anti-CD8 (OX8) and anti-CD5 (OX19), show a significantly lower than normal percentage of T-helper cells (CD5+/CD8-) and virtually no cytotoxic and suppressor (CD5+/CD8+) T cells. DP strains also have a slightly greater than normal percentage of NK cells (CD8+/ CD5-). DR strains are not lymphopenic and have a normal number of T cells (Like et al., 1991).
RT6 System
RT6 is a T-cell differentiation alloantigen controlled by two alleles RT6a and RT6h. Those alleles make two products, RT6.1 and RT6.2, respectively, which are co-expressed in F1 progeny derived from mating a strain that is RT6.1+ with a strain that is RT6.2+ (Crisá et al., 1992). Although normally absent on thymocytes and bone marrow cells, these cell-surface markers can be demonstrated on approximately 50 percent of CD4+ T-helper cells and 70 percent of CD8+ T-cytotoxic/suppressor cells. Overall, 60 percent of peripheral T cells express an RT6 marker. Intraepithelial lymphocytes (IELs) also express RT6 cell markers (Fangman et al., 1991). T cells that express RT6 markers are believed to be immunoregulatory (Greiner et al., 1988). Although DP strains have a functional RT6a allele (Crisfi et al., 1993), they do not express RT6.1 antigen on peripheral T cells, on splenocytes, or in lymph nodes. These rats do, however, express RT6.1 markers on their IELs (Fangman et al., 1991). DR strains express RT6.1 antigen in peripheral T cells, splenocytes, and in lymph nodes (Like et al., 1991).
Other immune abnormalities
DP rats develop autoantibodies to smooth muscle, thyroid colloid, gastric parietal cells, and islet cell-surface markers (Elder et al., 1982; Like et al., 1982a; Pipeleers et al., 1987; Dean et al., 1986). The significance of the production of autoantibodies and its pathogenic consequences to diabetes remains unclear. However, humans with organ-specific autoimmune disease typically produce similar autoantibodies.
More than 90 percent of BBBA/Wor, BBNA/Wor, and BBNB/Wor rats develop lymphocytic thyroiditis (LT) by 150 days of age (Stemthal et al., 1981; Rajatanavin et al., 1991), and the severity of the lymphocytic infiltration is more pronounced in these strains. In addition, the administration of iodine to the drinking water induces LT at an increased frequency by 90 days of age (Allen et al., 1986).
The peripheral T-cell receptor b-chain variable region (Vb) repertoire fails to develop in DP rats (Gold and Bellgrau, 1991). That limited Vb repertoire could be due to a differential T-cell expansion or a selective deletion of T-cell receptors. The importance of the defect and its contribution to the pathogenesis of diabetes requires further study.
DR rats do not spontaneously develop autoantibodies, LT, or insulitis. DR rats are not lymphopenic, but they do harbor an effector-cell population that can be induced to become autoreactive T cells, resulting in diabetes or thyroiditis (Like, 1990).
The DR rat is also an excellent animal model for studying collagen-induced arthritis. When immunized with human type II collagen suspended in incomplete Freunds adjuvant, virtually all DR rats develop arthritis within 10 days (Watson et al., 1990). It is a good model for collagen-induced arthritis because the third hypervariable region of the RT1.Db gene in DR rats encodes a nucleotide sequence identical to the human disease response genes (called HLA DR) associated with rheumatoid arthritis Watson et al., 1990).
GENETICS
In DP rats, susceptibility to diabetes is complex and requires the interaction of several genes. First, there is a close association of genes present in the major histocompatibility complex (MHC) encoding for the RTl" haplotype on chromosome 20 (Jacob et al., 1992). The development of diabetes is thought to be independent of class I expression but requires the presence of at least one class II RTl" allele (Fuks et al., 1990). Additional support for that hypothesis is derived from in vivo studies, which show that treatment of DP rats with a monoclonal antibody directed against class II RT1.D but not anti-RTI.B prevented diabetes (Boitard et al., 1985). Second, a recessive gene for lymphopenia, lyp, is permissive for diabetes and is tightly linked to the neuropeptide Y Nyp gene on chromosome 4 (Jacob et al., 1992). Lymphopenia segregates independently of the RTl" haplotype, and studies show that lyp is an autosomal recessive gene (Guberski et al., 1989; HeroId et al., 1989).
The relationship between lymphopenia and diabetes is also complex. While lymphopenia is permissive for diabetes, it is not an absolute requirement, because nonlympho-penic DR rats (BBDR/Wor and BBVB/Wor) can be induced to develop hyperglycemia by various means (Like et al., 1986a; Like, 1990). Other factors contributing to the diabetic phenotype include a dominant gene for PLI (called Pli) (Guttmann et al., 1983) and a proposed genetic factor that controls age at onset (Guberski et al., 1989). To date the use of biochemical and molecular markers have not identified a specific diabetogenic genotype (Kastern et al., 1984; Kryspin-Sorensen et al., 1986; Bjorck et al., 1986).
DR rats share the same MHC haplotype as DP rats but are not lymphopenic (Like et al., 1986a). If maintained in a pathogen-free environment, DR rats do not become diabetic. Since the rederivation of the strains in July 1989, more than ten thousand DR rats have been studied, and no diabetes has been detected. DR rats harbor effector cells capable of causing diabetes, however, and hyperglycemia can be induced by injection of polyinosinicpolycytidylic acid (usually called POLY-IC) (Sobel et al., 1992), x irradiation (Handler et al., 1989; Rossini et al., 1984a), and exposure to or injection of Kilham rat virus (KRV) (Guberski et al., 1991). RT6 depletion of conventionally housed DR rats can also induce diabetes (Greiner et al., 1987).
ENVIRONMENT
The diabetic phenotype is a combination of an animal's genetic predisposition and environmental factors that determine the penetrance of the diabetes genes. In inbred colonies of DP rats the genetic predisposition towards development of diabetes is uniform, but not all of the rats develop diabetes. Further, the incidence of diabetes varies among research institutions. One must therefore consider environmental factors, including viruses, bacteria, and diets.
Viruses
When the BB/Wor colony was rederived in 1989 by caesarian derivation, environmental pathogens were eliminated, causing significant changes in how many animals developed diabetes and at what age. Prior to rederivation, Sendai virus and sialodacryoadenitis virus were ubiquitous in the DP and DR colonies. The animals were seronegative for Mycoplasma pumonis and intermittently seropositive for KRV. The incidence of diabetes in DP rats was 70 percent, and the average age at onset was 91 days. Seven percent developed diabetes before 72 days of age, 74 percent between 72 and 102 days, and 19 percent after 103 days. After the viruses were eliminated, the incidence of diabetes increased from 70 percent to 86 percent, and the average age at onset was now 80 days. In addition, the distribution of ages at onset of diabetes was significantly earlier: 32 percent developed diabetes before 72 days of age, 62 percent between 72 and 102 days of age, and only 6 percent developed diabetes after 103 days. These studies (Like et al., 1991) suggest that viruses may modulate the immune system of DP rats by interfering with the genetically programmed process of [3-cell destruction. Additional support for the hypothesis of viral immune modulation is the observation that injecting lymphocytic choriomeningitis virus into young DP rats prevents diabetes (Dyrberg et al., 1988). Finally, Sadelain et al. (1990) has demonstrated that complete Freund's adjuvent (CFA) administered to young DP rats prevents diabetes, which suggests that CFA-induced cytokine release regulates immune responses. A review on cytokine regulation has recently been published (Rabinovitch, 1993).
Conversely, the incidence of spontaneous diabetes in DR rats was less than three percent before the elimination of environmental pathogens. Two spontaneous outbreaks of diabetes in DR rats were recorded, the first from 1984-1986 (Like et al., 1986a) and the second from 1988-1989 (Thomas et al., 1991; Sadelain et al., 1990). Following the first observations of diabetes in the DR population, breeding studies ruled out a genetic basis for nonlymphopenic diabetes. First, mating nonlymphopenic diabetic rats with normal DR rats did not increase the incidence of nonlymphopenic diabetes in the progeny. Second, matings in which both parents were nonlymphopenic and diabetic failed to produce diabetic offspring (Guberski et al., 1989). Retrospectively, the spontaneous outbreak was linked to the presence of KRV, a rodent parvovirus (Guberski et al., 1991). During the second outbreak of diabetes in the DR population, a virus, later determined to be KRV by sequencing of nonstructural protein (Brown et al., 1993), was isolated from the tissues of a diabetic DR rat. That virus, when injected into 21- to 25-day-old DR rats, induced diabetes and insulitis. Unlike other viruses that induce diabetes, KRV cannot be demonstrated in the pancreatic islets by immuno-histochemistry or in situ hybridization techniques (Guberski et al., 1991; Brown et al., 1993). When KRV is present, it is also permissive for induction of diabetes in DR rats following depletion of RT6.1+ T cells (Like, 1990). Injecting KRV into young DP rats fails to induce diabetes unless their immune systems have been reconstituted with splenocyte injections from DR rats. Similarly, immune reconstitution of DP rats with WF (Wistar Furth) splenocytes followed by KRV injection fails to induce diabetes (Guberski et al., 1991). These studies suggest that the immune system is being modified by the virus, possibly by viral molecular mimicry. Viral molecular mimicry could induce the pancreatic [3 cells to express a viral protein on the surface, thereby attracting immunocytes to destroy the "non-self" tissue. Another possibility is that KRV has a direct effect on the immune system, destroying the delicate balance between autoreactive effector and regulatory T cells. This mechanism could occur by either a virally induced stimulation of effector cells or a virally induced suppression of regulatory T cells. The hypothesis that the DR immune system is affected by KRV is derived from the following observations: 1) KRV injected into 21- to 25-day-old DP rats fails to induce diabetes; 2) DP rats whose immune systems are reconstituted by injections of splenocytes from either DR or WF rats do not become diabetic; 3) DP rats whose immune systems are reconstituted with splenocytes from DR rats and are subsequently injected with KRV become diabetic; and 4) DP rats whose immune systems are reconstituted with splenocytes from WF rats and subsequently injected with KRV do not become diabetic. These data clearly illustrate that KRV-induced diabetes requires a DR immune system since the target DP [3 cells were constant during these experiments (Guberski et al., 1991; Ellerman et al., 1992).
Bacteria
The concept that environmental pathogens or their extracel-lular products may initiate autoimmunity was recently tested by Ellerman and Like (1992). In these experiments staphylococcal entertoxins were used to stimulate RT6.1-depleted splenocytes in DR rats. Those stimulated spleen cells were effective in adoptively transferring diabetes, which clearly demonstrates that microbes are capable of activating autoreactive T cells, at least in vitro. Since approximately one-third of clinical isolates of Staphylococcus aureus produce enterotoxins, this ubiquitous pathogen may initiate an autoimmune process in genetically susceptible individuals.
Diets
The impacts of diet on development of diabetes have been studied extensively (Scott et al., 1985a,b; Behrens et al., 1986; Scott et al., 1988a,b; Scott and Marliss, 1991). Laboratory diets that utilize plant products, such as wheat gluten flour and soybean meal, are diabetes permissive. Semisynthetic diets rich in L-amino acids and hydrolyzed casein diets reduce the incidence and delay the onset of diabetes (Scott et al., 1988a), which may be caused directly by diet or indirectly by chemicals or microbiologic agents associated with the source of protein (Scott and Marliss, 1991).
TYPE I DIABETES, AN AUTOIMMUNE DISEASE
An immunopathogenesis for diabetes is suggested by the presence of insulitis in the pancreatic islets at the onset of hyperglycemia and by the ability to adoptively transfer disease by injecting spleen cells from diabetic rats into normal rats (Koevary et al., 1983). Cloned T-cell lines from diabetic rats are also capable of initiating 13-cell cytotoxicity (Reich et al., 1993). Diabetes can be prevented by neonatal thymectomy (Like et al., 1982b), injection of antilymphocyte sera (Like et al., 1979), and a variety of other immune modulatory techniques (Like et al., 1986b; Like et al., 1984; Rossini et al., 1984b). Finally, recent studies have shown that diabetes and insulitis can be prevented by transplanting islet cells from DP or DR rats into the thymus of neonatal DP rats, which suggests that establishing a state of tolerance prevents autoimmune destruction of pancreatic 13 cells (Koevary and Blomberg, 1992; Posselt et al., 1992).
HUSBANDRY
Housing
DP and DR rats should be maintained under pathogen~free conditions, such as in laminar-flow hoods, isolator cages, or barrier rooms, to avoid the impact of environmental pathogens (Like et al., 1991).
Detection and Clinical Care of Diabetes
Testing for glycosuria is the most efficient, cost-effective method to screen rats for diabetes. Urine is expressed manually from the bladder by pelvic compression and tested with Testape (Eli Lilly, Indianapolis, Indiana). A blood sample, which can be obtained by nicking the tip of the tail with a razor blade, should be taken within 2 hours of a positive test for glucosuria to ascertain blood sugar. Animals whose blood glucose concentrations exceed 250 mg/dl are considered diabetic and require insulin therapy. Testing for glycosuria should begin before the expected onset of diabetes and be performed at least three times each week at the start of the light cycle.
Insulin therapy. Daily treatment of diabetic rats with insulin is essential for their survival and should begin on the day that glycosuria is found and diabetes is confirmed. The daily dose of insulin will be a function of age, body weight, presence of ketoacidosis and dehydration, and whether the animal is pregnant or lactating. The starting dose of insulin should be 0.67 U/100g body weight. Complete direction for dealing with the various clinical emergencies are published in detail in Rodents: Laboratory Animal Management Series (NRC, in press). Briefly, the rat should be well hydrated, free of ketosis, gaining body weight, and maintained in a moderate state of glucosuria to avoid hypoglycemia. If ketonuria (as detected with a test strip) develops, the dose of insulin should be increased, and lactated Ringer's solution with sodium bicarbonate should be administered.
Treatment of hypoglycemia. The successful treatment of hypoglycemia requires a decrease in insulin dosage combined with subcutaneous fluid injections. Suggested regimens are reviewed in Rodents: Laboratory Animal Management Series (NRC, in press).
REFERENCES
Allen, E.M., M. C. Appel, and L. E. Braverman. 1986. The effect of iodide ingestion on the development of spontaneous lymphocytic thyroiditis in the diabetes-prone BB/W rat. Endocrinology 118:1977-1981.
Behrens, W. A., F. W. Scott, R. Madere, K. Trick, and K. Hanna. 1986. Effect of dietary vitamin E on the vitamin E status in the rat during development and after the onset of diabetes. Ann. Nutr. Metab. 30:157-165.
Bjorck, L., 1. Kryspin-Sorensen, T. Dyrberg, A. Letomark, and W. Kastem. 1986. A deletion in a rat major histocompatibility complex class 1 gene is linked to the absence of a beta 2-microglobulin-containing serum molecules. Proc. Natl. Acad. Sci. USA 83:5630-5633.
Boitard, C., S. Michie, P. Serrurier, G. W. Butcher, A. P. Larkins, and H. O. McDevin. 1985. In vivo prevention of thyroid and pancreatic autoim-munity in the BB rat by antibody to class II major histocompatibility complex gene products. Proc. Natl. Acad. Sci. USA 82:6627-6631.
Butler, L., D. L. Guberski, and A. A. Like. 1983. Genetic analysis of the BB/W diabetic rat. Canad. J. Genet. Cytol. 25:7-15.
Butler, L., D. L. Guberski, and A. A. Like. 1988. Genetics of diabetes production in the Worcester colony of the BB rat. Pp. 74-78 in Frontiers in Diabetes Research: Lessons from Animal Diabetes, Part II, E. Shafrir and A. E. RenoId, eds. London: John Libbey & Company.
Butler, L., D. L. Guberski, and A. A. Like. 1990. Changes in penetrance and onset of spontaneous diabetes in the BB/Wor rat. Pp. 50-53 in Frontiers in Diabetes Research: Lessons from Animal Diabetes, Part III, E. Shafrir, ed. London: Smith Gordon & Co., Ltd.
Chakrabarti, S., N. Ma, and A. A. S ima. 1989. Reduced number of anionic sites is assoiceted with glomerular basement membrane thickening in the diabetic BB rat. Diabetologia 32:826-828.
Chakrabarti, S., W. X. Zhang, and A. A. Sima. 1991. Optic neuropathy in the diabetic BB rat. Adv. Exp. Med. Biol. 291:257-264.
Cohen, A. J., P. D. McGill, R. G. Rosetti, D. L. Guberski, and A. A. Like. 1987. Glomerulopathy in spontaneously diabetic rats: Impact of glycemic control. Diabetes 36:944-951.
Crisá, L., J. P. Mordes, and A. A. Rossini. 1992. Autoimmune diabetes mellitus in the BB rat. Diab. Metab. Rev. 8:9-37.
Crisá, L., P. Sarkar, D. J. Waite, F. H. Friedrich, Koch-Nolte, T. V. Rajan, J.P. Mordes, E. S. Handler, H. G. Thiele, A. A. Rossini, and D. L. Greiner. 1993. An RT6a gene is transcribed and translated in lymphopenic diabetes-prone BB rats. Diabetes 42:688-695.
Dean, B.M., F. Becket, J. M. McNally, A. C. Tam, G. Schwartz, E. A. M. Gale, and G. F. Bottazzo. 1986. Insulin autoantibodies in the pre-dia-betic period: Correlation with islet cell antibodies and development of diabetes. Diabetologia 29:339-342.
Dyrberg, T., P. L. Schwimmbeck, and M. B. Oldstone. 1988. Inhibition of diabetes in BB rats by virus infection. J. Clin. Invest. 81:928-931.
Elder, M.E., and N. K. Maclaren. 1983. Identification of profound peripheral T lymphocyte immunodeficiencies in the spontaneously diabetic BB rat. J. Immunol. 130:1723-1731.
Elder, M., N. Maclaren, W. Riley, and T. McConnell. 1982. Gastric parietal and other autoantibodies in the BB rat. Diabetes 31:313-318.
Ellemlan, K. E., and A. A. Like. 1992. Staphylococcal enterotoxin-acti-vated spleen cells passively transfer diabetes in the BB/Wor rat. Diabetes 41:527-532.
Ellennan, K. E., D. L. Guberski, and A. A. Like. 1992. A viral trigger for autoimmune diabetes: Hypothesis no more. Pp. 61-64 in Lessons from Animal Diabetes, Part IV, E. Shafrir, ed. London: Smith-Gordon.
Ellennan, K., M. Wrobleski, A. Rabinovitch, A. A. Like. 1993. Natural killer cell depletion and diabetes mellitus in the BB/Wor rat (revisited). Diabetologia 36:596-601.
Fangman, J., R. Schwinzer, H. J. Hedrich, I. Kl6ting, and K. Wonigeit. 1991. Diabetes-prone BB rats express the RT6 alloantigen on intestinal intraepithelial lymphocytes. Eur. J. Immunol. 21:2011-2015.
Fuks, A., S. J. Ono, E. Colle, R. D. Guttmann. 1990. A single dose of the MHC-linked susceptibility determinant associated with the RTlu haplotype is permissive for insulin-dependent diabetes mellitus in the BB rat. Experimental and Clinical Immunogenetics 7:162-169.
Gepts, W. 1965. Pathological anatomy of the pancreas in juvenile diabetes mellitus. Diabetes 14:619-633.
Gold, D.P., and D. Bellgrau. 1991. Identification of a limited T-cell receptor b chain variable region repertoire associated with diabetes in the BB rat. Proc. Nat. Acad. Sci. USA 88:9888-9891.
Greene, D.A., S. Yagihashi, S. A. Lattimer, and A. A. Sima. 1984. Nerve Na+ - K+ - ATPase, conduction and myo-inositol in the insulin-defi-cient BB rat. Am. J. Physiol. 247:E534-E539.
Greiner, D.L., J. P. Mordes, E. S. Handler, M. Angelillo, N. Nakamura, and A. A. Rossini. 1987. Depletion of RT6.1+ T lymphocytes induces diabetes in resistant Biobreeding/Worcester (BB/W) rats. J. Exp. Med. 166:461-475.
Greiner, D.L., M. Angelillo, J. P. Mordes, E. S. Handler, C. F. Mojcik, N. Nakamura, and A. A. Rossini. 1988. Regulatory T cell control of au-toimmune destruction of beta cells in the BB rat. Adv. Exp. Med. Biol. 246:379-385.
Guberski, D.L., L. Butler, W. Kastem, A. A. Like. 1989. Genetic studies in inbred BB/Wor rats: Analysis of progeny produced by crossing lymphopenic diabetes-prone with non lymphopenic diabetic rats. Diabetes 38:887-893.
Guberski, D.L., V. A. Thomas, W. R. Shek, A. A. Like, E. S. Handler, A. A. Rossini, J. E. Wallace, and R. M. Welsh. 1991. Induction of type 1 diabetes by Kilham's rat virus in diabetes-resistant BB/Wor rats. Science 254:1010-1013.
Guttmann, R.D., E. Colic, F. Michel, and T. Seemayer. 1983. Spontaneous diabetes mellitus syndrome in the rat. II. T lymphopenia and its association with clinical disease and pancreatic lymphocytic infiltration. J. Immunol. 130:1732-1735.
Handler, E.S., J. P. Mordes, U. McKeever, N. Nakamura, J. Bernhard, D. L. Greiner, and A. A. Rossini. 1989. Effects of irradiation on diabetes in the BB/Wor rat. Autoimmunity 4:21-30.
Hedrich, H.J. 1993. Inbred strains in biomedical research. Pp. 1-7 in Genetic Monitoring of Inbred Strains of Rats, H. J. Hedrich, ed. Stuttgart: Gustav Fischer Verlag.
Herold, K.C., W. Kastem, H. Markhoist, A. Lernmark, B. E. Andreason. 1989. Derivation of non-lymphopenic BB rats with an intercross breeding. Autoimmunity 3:83-93.
Jacob, H.J., A. Pettersson, D. Wilson, Y. Mao, fi.. Lemmark, and E. S. Lander. 1992. Genetic dissection of autoimmune type I diabetes in the BB rat. Nat. Gen. 2:56-60.
Jiang, Z., and B. A. Woda. 1991. Cytokine gene expression in the islets of the diabetic biobreeding/Worcester rat. J. Immunol. 146:2990-2994.
Kastem, W., T. Dyrberg, J. Scholler, and I. Kryspin-Sorensen. 1984. Restriction fragment polymorphisms in the major histocompatibility complex of diabetic BB rats. Diabetes 33:807-809.
Kiesel, U., M. Oschilewski, G. Kantwerk, M. Maruta, H. Hanenberg, U. Treichel, V. Kolb-Bachofen, H. P. Hartung, and H. Kolb. 1986. Essential role of macrophages in the development of type I diabetes in BB rats. Transplant. Proc. XVIII:1525-1527.
Koevary, S. B., and M. Blomberg. 1992. Prevention of diabetes in BB/Wor rats by intrathymic islet injection. J. Clin. Invest. 89:512-516.
Koevary, S., A. A. Rossini, W. Stoller, W. L. Chick, and R. M. Williams. 1983. Passive transfer of diabetes in the BB/W rat. Science 220:727-728.
Kryspin Sorerisen, I., T. Dyrberg, and W. Kastem. 1986. Genetic heterogeneity in the major histocompatibility complex of various BB rat sub-lines. Diabetologia 29:307-312.
Lee, K.U., M. K. Kim, K. Amano, C. Y. Pak, M. A. Jaworski, J. G. Mehta, J. W. Yoon. 1988. Preferential infiltration ofmacrophages during early stages of insulitis in diabetes-prone BB rats. Diabetes 37:1053-1058.
Like, A. A. 1990. Depletion of RT6.1+ T lymphocytes alone is insufficient to induce diabetes in diabetes-resistant BB/Wor rats. Am. J. Pathol. 136:565-574.
Like, A. A., A. A. Rossini, D. L. Guberski, M. C. Appel, and R. M. Williams. 1979. Spontaneous diabetes mellitus: Reversal and prevention in the BB/W rat with anti-serum to rat lymphocytes. Science 206:1421-1423.
Like, A.A., M. C. Appel, and A. A. Rossini. 1982a. Autoantibodies in the BB/W rat. Diabetes 31:816-820.
Like, A. A., E. Kislauskis, R. M. Williams, and A. A. Rossini. 1982b. Neonatal thymectomy prevents spontaneous diabetes mellitus in the BB/ W rat. Science 216:644-646.
Like, A. A., V. DiRodi, S. Thomas, D. L. Guberski, and A. A. Rossini. 1984. Prevention of diabetes mellitus in the BB/W rat with cyclosporin-A. Am. J. Pathol. 117:92-97.
Like, A.A., D. L. Guberski, and L. Butler. 1986a. Diabetic BioBreeding/ Worcester (BB/Wor) rats need not be lymphopenic. J. Immunol. 136:3254-3258.
Like, A. A., C. A. Biron, E. J. Weringer, K. Byman, E. Sroczynski, and D. L. Guberski. 1986b. Prevention of diabetes in Biobreeding/Worcester rats with monoclonal antibodies that recognize T lymphocytes or natural killer cells. J. Exp. Med. 164:1145-1159.
Like, A.A., D. L. Guberski, and L. Butler. 1991. Influence of environmental viral agents on frequency and tempo of diabetes mellitus in BB/Wor rats. Diabetes 40:259-262.
McEwen, T.A., and A. A. Sima. 1987. Autonomic neuropathy in BB rat: Assessment by improved method for measuring heart-rate variability. Diabetes 36:251-255.
Murray, F.T., D. F. Cameron, J. M. Orth, and M. J. Katovich. 1985a. Gonadal dysfunction in the spontaneously diabetic BB rat: Alterations of testes morphology, serum testosterone and LH. Horm. Metab. Res. 17:495-501.
Murray, F.T., R. D. Johnson, M. Sciadini, M. J. Katovich, J. Rountree, and H. Jewem 1985b. Erectile and copulatory dysfunction in chronically diabetic BB/WOR rats. Am. J. Physiol. Endocrinol. Metabol. 263:E151-E157.
Nakhooda, A.F., A. A. Like, C. I. Chappel, F. T. Murray, and E. B. Marliss. 1977. The spontaneously diabetic Wistar rat: Metabolic and morphologic studies. Diabetes 26:100-112.
Pipeleers, D., M. Van de Winkel, T. Dyrberg, and A. Lemmark. 1987. Spontaneously diabetic BB rats have age-dependent islet B-cell-specific surface antibodies at clinical onset. Diabetes 36:111 l-I 115.
Posselt, A. M., C. F. Barker, A. L. Friedman, and A. Nail. 1992. Prevention of autoimmune diabetes in the BB rat by intrathymic islet transplantation at birth. Science 256:1321-1324.
Rabinovitch, A. 1993. Roles of cytokines in IDDM pathogenesis and islet b-cell destruction. Diabetes Rev. 1:215-240.
Rajatanavin, R., M. C. Appel, W. Reinhardt, S. Alex, Y-N Yang, and L. E. Braverman. 1991. Variable prevalence of lymphocytic thyroidiris among diabetes prone sublines of BB/Wor rats. Endocrinol. 128:153-157.
Reich, E. P., C. A. Janeway, I. Visintin, and R. S. Shetwin. 1993. Role of T-lymphocytes in murine lDDM. Diabetes Rev. 1:174-190.
Rossini, A.A., S. Slavin, B. A. Woda, M. Geisberg, A. A. Like, and J. P. Mordes. 1984a. Total lymphoid irradiation prevents diabetes mellitus in the BioBreeding/Worcester (BB/W) rat. Diabetes 33:543-547.
Rossini, A. A., D. Faustman, B. A. Woda, A. A. Like, I. Szymanski, and J. P. Mordes. 1984b. Lymphocyte transfusions prevent diabetes in the BioBreeding/Worcester rat. J. Clin. Invest. 74:39-46.
Sadelain, M. W. J., H-Y Qin, W. Sumoski, N. Parfrey, B. Singh, and A. Rabinovitch. 1990. Prevention of diabetes in the BB rat by early immu-notherapy using Freund's adjuvant. J. Autoimm. 3:671-680.
Scott, F. W., and E. B. Marliss. 1991. Conference summary: Diet as an environmental factor in development of insulin-dependent diabetes mellitus. Can. J. Phys. Pharm. 69(3):311-319.
Scott, F. W., R. Mongeau, M. Kardish, G. Hatina, K. D. Trick, and Z. Wojcinski. 1985a. Diet can prevent diabetes in the BB rat. Diabetes 34:1059-1062.
Scott, F. W., R. Mongeau, and W. A. Behrens. 1985b. Diet and insulin-dependent diabetes in the BB rat (letter). Diabetologia 28:59-61.
Scott, F. W., G. Sarwar, and H. E. CloutJer. 1988a. Diabetogenicity of various protein sources in the diet of the diabetes-prone BB rat. Adv. Exp. Med. Biol. 246:277-285.
Scott, F. W., D. Daneman, and J. M. Martin. 1988b. Evidence for a critical role of diet in the development of insulin-dependent diabetes mellitus. Diabetes Res. 7(4): 153-157.
Shachner, M. S., J. F. Markmann, H. Bassiri, J. I. Kim, A. Nail, and C. F. Barker. 1992. Direct assessment of the role of NK cells in autoimmune diabetes. J. Surg. Res. 52:601-604.
Sinla, A.A., S. Chakrabarti, R. Garcia-Salinas, and P. K. Basu. 1985. The BB rat--an authentic model of human diabetic retinopathy. Curr. Eye Res. 4:1087-1092.
Sima, A. A., S. A. Lattimer, S. Yagihashi, and D. A. Greene. 1986. Axo-glial dysjunction:A novel structural lesion that accounts for poorly reversible slowing of nerve conduction in the spontaneously diabetic bio-breeding rat. J. Clin. Invest. 77:474-484.
Sobel, D.O., J. Newsome, C. H. Ewel, J. A. Bellanti, V. Abbassi, K. Creswell, and O. Blair. 1992. Poly I:C induces development of diabetes mellitus in BB rat. Diabetes 41:515-520.
Sternthai, E., A. A. Like, K. Sarantis, and L. E. Braverman. 1981. Lymphocytic thyroidiris and diabetes in the BB/W rat. A new model of autoimmune endocrinopathy. Diabetes 30:1058-1061.
Thomas, V.A., B. A. Woda, E. S. Handler, D. L. Greiner, J. P. Mordes, and A. A. Rossini. 1991. Altered expression of diabetes in BB/Wor rats by exposure to viral pathogens. Diabetes 40:255-258.
Watson, W.C., J. P. Thompson, K. Terato, M. A. Cremer, and A. H. Kang. 1990. Human HLA-DRb gene hypervariable region homology in the biobreeding BB rat: Selection of the diabetic-resistant subline as a rheumatoid arthritis research tool to characterize the immunopathologic response to human type II collagen. J. Exp. Med. 172:1331-1339.
Yagihashi, S., and A. A. Sima. 1985a. Diabetic autonomic neuropathy: The distribution of structural changes in sympathetic nerves of the BB rat. Am. J. Pathol. 121:138-147.
Yagihashi, S., and A. A. Sima. 1985b. Diabetic autonomic neuropathy in the BB rat. Ultrastructural and morphometric changes in sympathetic nerves. Diabetes 34:558-564.
Yagihashi, S., and A. A. Sima. 1986. Neuroaxonal and dendritic dystrophy in diabetic autonomic neuropathy: Classification and topographic distribution in the BB rat. J. Neuropathol. Exp. Neurol. 45:545-565.
TABLE 1 Characteristics of Diabetes Prone and Diabetes Resistant Rats
| Diabetes prone (DP) rat strains | Diabetes Resistant (DR) rat strains | |||||||
| BBBA | BBDP | BBBE | BBNA | BBNB | BBPA | BBDR | BBVB | |
| lnsulitis | ||||||||
| Incidence of Diabetes (GEN 41-45) | ||||||||
| Lymphopenia | ||||||||
| RT6.1+ T cells | ||||||||
| Thelper | ||||||||
| Tcytotoxic/suppressor | ||||||||
| Thyroiditis | ||||||||
| MHC RTlu | ||||||||
TABLE 2 Treatment for ketonuria in diabetes-prone rats
| Ketones | Increased insulina (U/100g body wt) | Lactated ringers (cc) | Sodium bicarbonate (meq)b |
| 2+ | 0.2 | 10.0 | 0.0 |
| 3+ | 0.2 | 9.0 | 1.0 |
| 4+ | 0.2 | 18.0 | 2.0 |
a insulin dose of lactating females should not exceed 1.0 U/100 g IBW. Do not increase insulin during mild episodes of ketonuria.
b 1 cc of 8.4% sodium bicarbonate equals 1 meq.
TABLE 3 Treatment for hypoglycemia in diabetes-prone (DP) rats
| Classification (blood glucose concentration) | Fluid therapy (subcutaneous) | Dose of insulin | Time of insulin administration |
| Severe <40 mg/dl | Give 1 cc 50% dextrose; 2 hrs later give lactated Ringers with 5% dextrose | Reduce 30-50% | Delay 2-3 hrs |
| Moderate 40-60 mg/dl | Give 10 cc lactated Ringers with 5% dextrose | Reduce 20-30% | Delay 2-3 hrs |
| Mild 60-80 mg/dl | Give 10 cc lactated Ringers | Reduce 10-15% | No delay |
TABLE 4 Reproduction in diabetes-prone (DP) rats before and after receiving splenocytes from diabetes-resistant (DR) rats
| DP females not treated with splenocytes | DP females treated with splenocytes | |
| Incidence of diabetes | 86% (N = 1,238) | 16% (N = 1,022) |
| Number of pups born | 7,160 | 12,434 |
| Number weaned | 5,766 | 10,918 |
| Percent surviving | 80% | 88% |
| Pups weaned/female mated | 4.7 | 10.7 |
FIGURE 1 Age at onset of diabetes n diabetes-prone BB/Wor rats was determined by glycosuric testing animals 3 times per week. Diabetes was defined as 4+ glycosuria with subsequent sera glucose measurement greater than 250 mg%/(13.8mmol/L). Animals studied represent viral antibody-free breeders from all diabetes-prone lines from generations 37-48.
FIGURE 2 Clinical course of diabetes in 23 lean diabetic male rats after cessation of insulin therapy. Twenty out of twenty-three rats died in diabetic ketoacidosis within 4 days after cessation of insulin therapy.
FIGURE 3 Normal islet from a BBDR/Wor rat. The centrally located b cells stain intensely for insulin (3A). Alpha cells located at the islets periphery stain positively for glucagon (3B).
FIGURE 4 Islet from an acutely diabetic BB rat. Insulitis is widespread and is responsible for the destruction of the insulin producing b cells (4A). Glucagon positive cells (4B) are unaffected.
FIGURE 5 End stage islet from a chronically diabetic BB rat. Insulin positive b cells are absent (5A) due to autoimmune destruction of pancreatic b cells. Peripherally located b cells (5B) have clustered following the collapse of the centrally located b cell core.
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