Prevalence and conditions of urinary incontinence among the elderly

In Japan, elderly disorders and diseases have markedly increased in recent years, because of rapid aging and an increasing number of older persons. The situation is creating serious social and community problems. These disorders, particularly dysuria and urinary incontinence (UI), disturb the quality of life (QOL) in latelife. Few reports on UI have been published, but precise investigation into the community level remains to be made. Our presentation is the development, implementation and evaluation of elderly UI in Kumamoto Prefecture. This study includes 2,304 people (male: 856, female: 1,448), over 65 years of age, living in two different communities; one is an urban (K) and the other is a typical rural area (S). The rate of UI was in homebound elderly persons, male: 4.7%, female: 11.3%, and in nursing home residents, male: 16.2%, female: 23.2%. The condition of UI was: almost Urinary Urgency in male (61.5%), and Stress Incontinence (such as, caused by coughing, sneezing, and exercise) in female (46.3%). The influence of UI on the activity of daily life was investigated. Most of the male cases were giving concerns for family and community. In contrast, females hesitated to participate in group excursions and outdoor exercise, and had a tendency to live alone or indoors. However, most persons (81.5%) with UI did not visit a physician. From this investigation, we conclude that a community health care program and public support system are essential for proper understanding and solution of the elderly UI problem.

[Three patients with insulin-treated diabetes and senile dementia of Alzheimer's type]

Senile dementia of Alzheimer's type (SDAT) is reported to be less frequent in patients with Diabetes Mellitus. However the, the number of elderly people in still increasing in Japan, an is the incidence of diabetes mellitus, especially in middle-aged and elderly people. Thus, we can expect to encounter more elderly people with diabetes and SDAT. We encountered three patients with diabetes who were treated with insulin and in whom SDAT developed. In all three, control of blood glucose levels gradually worsened, despite increases in the dose of injected insulin. It was later found that they did not inject insulin properly because of SDAT. They lived alone and their dementia was not diagnosed before their admission to the hospital. In its early phase, SDAT can be difficult to diagnose, especially in patients who live alone. SDAT should be considered when the control of blood glucose levels for no apparent reason in elderly patients with diabetes.

Combination of OK432 and human interferon-alpha for treating viral-induced diabetes mellitus in mice

We investigated the therapeutic effects of OK432 (picibanil; CAS39325-1-4), an immunomodulator that is derived from the Su strain of Streptococcus pyogenes. This agent was administered alone or combined with human interferon-alpha in a murine model of insulin-dependent diabetes mellitus. Interferon-alpha inhibits viral replication, reducing the incidence of virus-induced IDDM. Groups of DBA/2 mice (N = 25 per group) received an intraperitoneal injection of OK432 and interferon-alpha daily for 16 d beginning 1 d after inoculation with 500 plaque-forming units of encephalomyocarditis virus (EMCV). The dose of OK432 was one clinical unit (corresponding to 0.1 mg dried cells) per mouse, and that of interferon-alpha was 1 x 10(4) u/g. The animals were killed at random at 3 or 7 d after inoculation with EMCV. The survival rate of mice treated with the combination of OK432 and with interferon-alpha was significantly greater than that of the non-treated infected control animals (P < 0.01). Fasting levels of blood glucose were significantly lower in the mice administered the combination, than in the controls, both on day 3 (68 +/- 21 mg/dl vs. 270 +/- 135 mg/dl, P < 0.01) and on day 7 (101 +/- 29 mg/dl vs. 219 +/- 112 mg/dl, P < 0.01). Serum levels of insulin were significantly higher in the treated mice than in the controls (65 +/- 5 vs. 55 +/- 1 microU/ml, P < 0.05). However, in the mice treated with OK432 or interferon-alpha alone, the survival rate and the blood level of glucose and insulin did not differ from those of infected controls. Natural killer (NK) cell activity was significantly higher in the mice treated with the drug combination than in the controls on both days evaluated: day 3, 65 +/- 5 vs. 55 +/- 1%, n = 3, P < 0.05; day 7, 44 +/- 3 vs. 22 +/- 8%, n = 3, P < 0.05). Serum levels of murine interferon in the treated mice exceeded those in controls on both days evaluated (day 3, 671 U/ml vs. 442 U/ml; day 7, 57 U/ml vs. 43 U/ml). There were no significant differences in NK cell activity or in the interferon level in mice treated with either OK432 or interferon-alpha alone as compared with the infected, non-treated controls. Results suggest that the combination of OK432 and interferon-alpha protects against virally induced IDDM by increasing the activity of NK cells as well as the plasma level of interferon.

Effects of passive immunization against oestradiol-17beta and inhibin on the secretion of gonadotrophin in the cyclic golden hamster (Mesocricetus auratus)

To investigate the physiological importance of oestradiol-17beta and inhibin in the regulation of gonadotrophin secretion in the cyclic golden hamster, females were passively immunized against two hormones. When 200 microL antiserum against oestradiol-17beta (oestradiol-AS) was given on Day 3 (Day 1 = day of ovulation), the preovulatory gonadotrophin surge was completely blocked for 24 h and the length of the oestrous cycle was also prolonged for one day. In the group given 200 microL oestradiol-AS on Day 3, basal levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) increased slightly and superovulation (19.6+/-0.8, mean+/-s.e.m.) occurred. When 200 microL antiserum against inhibin (inhibin-AS) was given at 1100 hours on Day 3, a dramatic increase in plasma FSH and a slight increase in LH were noted, resulting in superovulation (38.2+/-2.6) on the expected Day 1. The present study indicates clearly that inhibin plays a major role in regulating the specific ovulation rate in the hamster through the control of FSH secretion. Present results also indicate that oestradiol-17beta suppresses basal LH secretion. Oestradiol-17beta may act as an indicator of the follicular maturation, and the high plasma concentration of oestradiol-17beta noted from Day 3 to Day 4 may play an important role in determining the timing of initiation of the preovulatory gonadotrophin surge.

Discrimination of eight chicken Eimeria species using the two-step polymerase chain reaction

A method was developed for the discrimination of 8 Eimeria species of chickens, i.e., E. acervulina, E. brunetti, E. mitis, E. maxima, E. necatrix, E. praecox, E. tenella, and E. hagani using the 2-step polymerase chain reaction (PCR). In the first PCR, the small subunit ribosomal RNA (srRNA) gene was amplified from the parasite genome using conserved sequences for the Apicomplexa srRNA gene as the primers. The srRNA gene amplified from the parasite genome was discriminated in the second step by random-amplified polymorphic DNA (RAPD) PCR using 10 arbitrary primers. Each arbitrary primer produced species-specific RAPD patterns that provided a simple method for species identification from the srRNA genes of the 8 Eimeria species. This method should be useful for discrimination of the parasite species for diagnosis or epidemiological surveys of chicken coccidiosis.

Stage-independent splicing of transcripts two heterogeneous neighboring genes in Leishmania amazonensis

Gene expression in trypanosomatid protozoa is largely regulated posttranscriptionally, e.g., 5' splice leader addition and 3' polyadenylation of mRNAs. We examined these events in Leishmania by mapping the splice sites of the transcripts from two different, but closely linked single-copy genes 2.3 kb apart. The coding regions of the approx. 1 kb upstream gene (P36) and the approx. 1.4 kb downstream gene (NAGT) produce approx. 2 and 3 kb mRNAs, respectively. Both genes were overexpressed in cells that were transfected with this bicistronic unit (> or = 7.5 kb), taking advantage of the NAGT as a selectable marker for tunicamycin-resistance. The transcripts from both genes were spliced constitutively at both ends, irrespective of their episomal or chromosomal expression in both leishmanial stages. Primer extension of the 5' UTRs and S1 nuclease protection of the 3' UTRs initially identified the major splice sites, corresponding to the genomic sequence at -205 bp and + approx. 900 bp of P36, and -1012 bp and + approx. 600 bp of NAGT. These splice sites, consistent with the size of the major transcripts, are among those mapped precisely by sequencing RT-PCR amplified 5' and 3' UTRs. The additional sites mapped by the latter are minor alternatives, especially abundant for transcripts of the downstream NAGT. All these minor splice sites are closer than the major splice sites to the coding region, indicating that the most distant splice sites are preferentially used. This preference creates a 387 bp 'gap' with polypyrimidine tracts in the intergenic region consistent with the model coupling splice leader addition with polyadenylation in pre-mRNA processing. The stage-independence of these events suggests that the 7.5 kb dicistronic unit is suitable for constructing Leishmania-specific constitutive expression vectors.

A polymorphism observed in the experimentally successful peptide vaccine sequence derived from Theileria sergenti piroplasm major surface antigen (p33)

A polymorphism in the experimentally successful peptide vaccine sequence (EVVWKEKKEVKDLDA, amino acids 134-148) derived from the 33 kDa piroplasm major surface antigen (p33) of Theileria sergenti was examined. The vaccine sequences obtained by PCR amplification and sequencing of the p33 gene from a total of 15 parasite-infected cattle blood samples collected from 4 prefectures through Hokkaido to Kumamoto revealed the two major sequences (Ikeda and Chitose stock types) either of which was identified in all samples. Since the peptide vaccine develops the parasite species- or stock-specific immunity in the animals, an application of the two major peptide sequences as cocktailed vaccine should be evaluated for a practical use of this strategy to controlling T. sergenti infection in Japan.

Change of plasma 1,5-anhydro-D-glucitol levels after the onset of diabetes in spontaneous diabetes prone BB/Wor/(/)Tky rats

Plasma 1,5-anhydro-D-glucitol (AG) is a marker of the diabetic state and also reflects the glycosuria induced by hyperglycemia but not by renal pathology. To investigate the benefits of the AG determination in order to diagnose diabetes in BB/Wor/(/)Tky rats, AG was measured in non-diabetic (n = 104) and diabetic (n = 113) BB/Wor/(/)Tky rats. AG was significantly higher in non-diabetic rats than in diabetic rats (25.2 +/- 9.3 vs 4.1 +/- 7.4 micrograms/ ml, mean +/- SD, p < 0.001). The best cut-off level for AG (8.5 micrograms/ml) was highly specific (100%) for ruling out diabetes and fairly sensitive (82.3%) to detect diabetes. Based on the AG cut-off levels, 90% of false-negative diabetic rats (18/20) were observed within 4 days after the onset of diabetes, which corresponded to 38.3% in diabetic rats (18/47) at that time. The false-negative diabetic rats and positive rats could be effectively distinguished based on the cumulative points given according to the urinary glucose after the onset of diabetes. 1 point for each cross [+] indicating glycosuria using the Testape, i.e. 2 or less points false negative and 4 or more points for diabetic rats in the first 4 days. In conclusion, there is a close inverse relation between the level of plasma AG and the amount of glycosuria detected just after the onset of overt diabetes in BB/Wor/(/)Tky rats.

Experimental transmission of Babesia ovata oshimensis n. var. of cattle in Japan by Haemaphysalis longicornis

Transovarial transmission of a newly isolated large intraerythrocytic parasite, Babesia sp. 1 by Haemaphysalis longicornis was experimentally demonstrated. Larvae of H. longicornis were transovarially infected with the parasite by feeding as adults on the calf which had been experimentally infected with B. sp. 1. Piroplasms of B. sp. 1 were observed in peripheral blood of the calf which was infested with the parasite-infected larvae. Based on the transmissibility of the parasite with vector ticks, this parasite was suggested to be a variety of B. ovata. Thus, we propose a new variety name for B. sp. 1 as B. ovata oshimensis n. var.

[Coronary artery disease]

Those who have IGT (impaired glucose tolerance) are thought to be highly risky to atherosclerotic coronary artery disease (CAD), probably because of the frequent association with insulin resistance or hyperinsulinemia, obesity or abdominal fat accumulation, hypertriglyceridemia and so on. Whether insulin resistance which is one of the major causes of IGT, following hyperglycemia itself or both is really responsible for CAD is remained to be clarified. Furthermore, IGT is also an apparent candidate for NIDDM in future. Thus, IGT should be intensively treated to prevent or delay the onset of NIDDM and also to minimize the adverse events by atherosclerotic CAD.

Major histocompatibility complex class I-restricted infiltration and destruction of pancreatic islets by NOD mouse-derived beta-cell cytotoxic CD8+ T-cell clones in vivo

NOD mouse-derived beta-cell-specific cytotoxic T-cell (beta-CTL) clones are diabetogenic in adult NOD mice, but only if co-injected with splenic CD4+ T-cells from diabetic animals. This investigation was initiated to determine whether infiltration of pancreatic islets by beta-CTL is a major histocompatibility complex (MHC) class I-restricted response, and whether beta-CTL has a direct cytopathic effect on beta-cells in vivo. Pancreatic islets from BALB/c (H-2d) or B6 (H-2b) mice were transplanted under the renal capsule of streptozotocin (STZ)-induced diabetic (NOD x BALB/c) F1 (H-2Kd, H-2Dd,b) or NOD x B6) F1 (H-2Kd,b, H-2Db) mice, respectively. H-2Kd-restricted beta-CTL clones from NOD mice were transfused into euglycemic mice within 3 days after transplantation. In all of the H-2d islet-grafted (NOD x BALB/c) F1 mice that received the beta-CTL clones, the beta-CTLs homed into the grafts, recruited host Mac-1+ cells and CD4+ and CD8+ T-cells, and caused diabetes within 7 days. In contrast, none of the H-2b islet-grafted (NOD x B6) F1 mice who received the beta-CTL clones and none of the H-2d islet-grafted (NOD x BALB/c) F1 mice who received a non-beta-cell cytotoxic CTL clone (N beta-CTL) developed graft inflammation or diabetes. Depletion of CD4+ T-cells in H-2d islet-grafted (NOD x BALB/c) F1 mice did not prevent beta-CTL clone-induced diabetes but reduced its severity. In contrast, when the beta-CTL clones were injected > 8 days after transplantation, none of the H-2d islet-grafted (NOD x BALB/c) F1 mice became diabetic or developed graft inflammation. We conclude that (1) islet-derived beta-CTLs can destroy beta-cells in vivo; (2) infiltration of grafted islets by beta-CTLs is an MHC class I-restricted response; (3) beta-CTLs can recruit naive CD4+ T-cells to the site, leading to further beta-cell damage; and (4) revascularized islet grafts are, like pancreatic islets of irradiated adult NOD mice, "sequestered" from circulating beta-CTLs.

A higher proinsulin response to glucose loading predicts deteriorating fasting plasma glucose and worsening to diabetes in subjects with impaired glucose tolerance

To evaluate the clinical significance of proinsulin determination, we measured glucose, insulin, C-peptide and proinsulin during 75-g oral glucose loading in 59 patients. In a 2.5-year follow-up study of 37 subjects with impaired glucose tolerance (IGT) at the initial test, 11 patients changed from IGT to a normal state and 5 patients showed worsening to overt Type 2 diabetes with elevation of fasting plasma glucose; 21 patients remained unchanged. Although our data showed that both fasting (IGT: p = 0.4523) and 120-min plasma glucose (IGT: p = 0.8168) values at the initial test were not significantly correlated with increased fasting plasma glucose levels in a 2.5-year follow-up study, subjects with a higher 120-min proinsulin response to glucose during the initial OGTT showed a significant correlation (IGT: p < 0.0001) with increased fasting plasma glucose levels after follow-up period and developed Type 2 diabetes. The present findings suggest that the proinsulin response to glucose loading might be a useful indicator for predicting worsening to diabetes in subjects with impaired glucose tolerance.

Evaluation of cardiac sympathetic nervous function by 123I-metaiodobenzylguanidine scintigraphy in insulin-treated non-insulin dependent diabetics with hypoglycemia unawareness

The association between the lack of adrenergic symptoms during hypoglycemia and myocardial 123I-metaiodobenzylguanidine (MIBG) accumulation was investigated in 12 insulin-treated non-insulin-dependent diabetes mellitus (NIDDM) patients who had no evidence of heart disease. These patients were divided into 2 groups according to the presence (group A) or absence (group B) of adrenergic symptoms during hypoglycemia. Autonomic function tests revealed significantly severe autonomic dysfunction in group B compared to that in group A. Insulin infusion test indicated no significant difference in the catecholamine response between the two groups. 123I-MIBG scintigraphy showed that the heart/mediastinum ratio of MIBG uptake was significantly lower, and scintigraphic defect was greater in group B than in group A. There were no significant differences in the washout rate between the two groups. These results suggested that the lack of adrenergic symptoms during hypoglycemia may be associated with cardiac sympathetic nervous dysfunction in insulin-treated NIDDM patients, and this dysfunction is mainly due to cardiac sympathetic denervation.

Association analyses of the polymorphisms of angiotensin-converting enzyme and angiotensinogen genes with diabetic nephropathy in Japanese non-insulin-dependent diabetics

To investigate predictive genetic markers for diabetic nephropathy, we studied the genetic polymorphisms of angiotensin-converting enzyme (ACE) and angiotensinogen (AGN) in Japanese subjects with non-insulin-dependent diabetes mellitus (NIDDM) with and without nephropathy. Genotype distributions were studied in 132 unrelated NIDDM patients of three groups with normoalbuminuria ([Normo] n = 53), microalbuminuria ([Micro] n = 54), and macroalbuminuria ([Macro] n = 25). The ACE insertion/deletion (I/D) polymorphism of intron 16 was identified by polymerase chain reaction, and the AGN M235T polymorphism was identified by restriction fragment length polymorphism analysis. There were no significant associations between AGN 235 allele or genotype and diabetic nephropathy. The D allele of ACE was significantly more frequent in the Micro (P = .003) and Macro (P = .009) group than in the Normo group. Overall frequencies of the ACE genotype did not differ significantly between the Micro and Macro groups. There were significant relationships between I/D polymorphism and plasma ACE activity; the DD genotype had the highest activity. A multiple logistic regression analysis revealed that the D allele is a strong and independent risk factor for abnormal albuminuria in NIDDM patients. These results suggested that ACE I/D polymorphism, but not AGN M235T polymorphism, is a possible genetic risk factor for diabetic nephropathy in Japanese NIDDM patients.

Age-related alteration of pancreatic beta-cell function. Increased proinsulin and proinsulin-to-insulin molar ratio in elderly, but not in obese, subjects without glucose intolerance

OBJECTIVE

To determine the secretion of insulin, C-peptide, and proinsulin after oral glucose loading in healthy elderly subjects compared with middle-aged subjects with and without obesity and with NIDDM.

RESEARCH DESIGN AND METHODS

Subjects fell into four groups: nonobese middle-aged normal control subjects (CNT group; n = 38, 40-64 years old); obese normal subjects (OB group; n = 18, 40-64 years old); nonobese NIDDM subjects (NIDDM group; n = 28, 40-64 years old); and nonobese elderly subjects (OL group; n = 17, 65-92 years old). Insulin, C-peptide, and proinsulin were determined by radioimmunoassay in plasma samples taken at 0, 30, 60, and 120 min during a 75-g oral glucose tolerance test (OGTT).

RESULTS

There were no differences in plasma glucose during the OGTT among the three nondiabetic groups. Hyperinsulinemia was significant in the OB and NIDDM groups but not in the OL group. On the other hand, absolute hyperproinsulinemia was significant in the OL and NIDDM groups compared with the CNT group. Increased proinsulin was rather dominant in the OL group, especially late after glucose loading. Molar ratios of proinsulin to insulin or C-peptide thus were significantly higher in the OL and NIDDM groups.

CONCLUSIONS

Alteration of pancreatic beta-cell function independent of that seen with NIDDM occurred in relation to aging. This may be a predisposing factor to the development of impaired glucose tolerance or NIDDM in elderly subjects, that is, independent of obesity.

Theileria sergenti and T. buffeli: polymerase chain reaction-based marker system for differentiating the parasite species from infected cattle blood and infected tick salivary gland

Benign Theileria species in cattle. Theileria sergenti and T. buffeli, are morphologically indistinguishable. The polymerase chain reaction (PCR) was used to amplify the genes encoding the 33- and 34-kDa major piroplasm antigens (p33/34) of T. sergenti and T. buffeli from cattle blood infected with these parasites and tick salivary gland infected with T. sergenti. Following amplification, the p33 gene from T. sergenti and the p34 gene from T. buffeli were clearly differentiated using the restriction enzyme sites that were not shared between them. The oligonucleotide primer set, designed from the p33/34 genes, was specific for these Theileria species, since no amplification was detected with DNA from Babesia ovata, B. bovis, Anaplasma marginale, A. centrale, Eperythrozoon wenyoni, bovine white blood cells, and uninfected tick salivary glands. One tenth vol of the template prepared from either 25 microliters of blood with 0.5% parasitemia or individual tick salivary glands with six infected acini allowed sufficient amplification for differentiation of the two parasite species by restriction enzyme digestion. In addition, this system could be used to demonstrate the simultaneous, experimentally induced infection of cattle with T. sergenti and T. buffeli. The PCR-based marker system therefore provides a means to differentiate T. sergenti from T. buffeli in infected cattle blood and infected tick salivary glands. This system may also be useful for the characterization of other benign Theileria species in cattle.

Increased expression of a regenerating (reg) gene protein in neonatal rat pancreas treated with streptozotocin

We examined the expression of reg protein in neonatal rat pancreas treated with streptozotocin (STZ) by means of the immunohistochemical technique and northern blotting. Seven days after STZ injection, the plasma glucose levels in STZ-treated neonatal rats were significantly higher than those in control rats. Scattered distribution of reg protein in pancreatic islet cells was clearly observed in STZ-treated rats, but not in control rats. On the other hand, reg proteins was positively stained in the exocrine cells in both groups of rats. Northern blot analyses revealed that the expression of insulin mRNA markedly decreased in STZ-treated rat pancreas, but a significant increase in reg mRNA expression was recognized in the STZ-treated rat pancreas compared with that of control rats. Rats treated with STZ during the neonatal period have been used as a model of non-insulin-dependent diabetes mellitus (NIDDM) and beta cell regeneration. Thus, the increased reg gene expression in neonatal STZ-treated rat pancreas was therefore described for the first time, and thus would be a useful model for studying the relationship between NIDDM and beta cell regeneration or reg gene protein.

Selection of diversity at putative glycosylation sites in the immunodominant merozoite/piroplasm surface antigen of Theileria parasites

The immunodominant merozoite/piroplasm surface antigen of Theileria parasites has potential as a diagnostic reagent and as a component of a sub-unit vaccine. This molecule is known to be antigenically diverse, and it is important to determine the nature and extent of this heterogeneity. In the present study nucleotide sequences, representing alleles of the gene (Tams1) encoding this molecule in Theileria annulata were compared to each other and to sequences of homologous genes in Theileria sergenti, Theileria buffeli and Theileria parva. This analysis revealed that a region of the polypeptide which contains putative N-linked glycosylation sites is particularly diverse and, in analogy to retroviral systems, may indicate selection of variable glycosylation sites or amino acid epitopes to evade the bovine immune response. This conclusion was also made from the results of a phylogenetic analysis which compared the variable region of the genes with a second region, which appeared to show no bias for diversity or functional constraint. The results indicated that the variable sequence encoding putative glycosylation sites has diverged, both within and between Theileria species, at a much faster rate than the rest of the molecule. Southern blot analysis of T. annulata populations from within a single geographical region detected six possible variant Tams1 alleles. However, a correlation between restriction-fragment-length polymorphism (RFLP) patterns detected by the Tams1-1 gene probe and geographical location could not be made. In addition, although a high prevalence of one particular RFLP was found, this is unlikely to be the result of a clonal population structure, as we present evidence for significant parasite genotypic variability within a single endemic region.

Effects of posture on creatinine clearance and urinary protein excretion in patients with various renal diseases

To investigate the effects of a change in posture on renal function, we measured Ccr and the urinary excretion of protein, albumin, immunoglobulin G (IgG) and transferrin in 80 patients with renal disease and in 9 healthy controls. Patients and controls were studied serially while supine for 60 min; then after standing upright for 60 min. Almost all subjects showed a drop in the Ccr with standing (p < 0.01). The percent change in Ccr after standing was more remarkable in patients with glomerulonephritis vs the healthy subjects (74.0 +/- 21.9% vs 89.9 +/- 12.3%, p < 0.01). The change in urinary excretion of protein and albumin after standing in patients with membranous nephropathy (MN-N) significantly exceeded that in patients with IgA nephropathy (IgA-N) (182.1 +/- 89.3% vs 108.1 +/- 59.2% in urinary protein and 181.7 +/- 98.7% vs 113.3 +/- 40.9% in urinary albumin, p < 0.01). Urinary excretion of IgG and transferrin tended to increase after standing in those two groups, but not significantly. Results indicate that posture affects urinary protein excretion, probably via an increase of glomerulocapillary hydrostatic pressure and/or change in the permeability of the glomerular capillary walls. We recommend that comparable postures should be used when protein excretion is used as a diagnostic tool and in monitoring structural damage to glomeruli, particularly in patients with membranous nephropathy.

Beta-cell-cytotoxic CD8+ T cells from nonobese diabetic mice use highly homologous T cell receptor alpha-chain CDR3 sequences

Insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a cell-mediated autoimmune process against pancreatic beta-cells. We have shown that beta-cell-cytotoxic CD8+ T cell clones can transfer IDDM to irradiated NOD mice if co-injected with nondiabetogenic CD4+ spleen T cells. To determine whether CTLs recruited to pancreatic islets recognize a restricted set of local Ags, we sequenced TCR-alpha and TCR-beta cDNA generated by anchor PCR from CD8+ CTL lines and clones derived from islets of 10 different NOD mice. These CTL lines were oligoclonal, but did not show skewed V alpha, V beta, J alpha, or J beta gene usage when compared with CD8+ spleen T cells. However, of the 26 different CTL-derived TCR-alpha sequences from all of these CTL lines and clones, 17 (65%) used one of three highly related, N region-encoded, CDR3 motifs. Motifs 1 and 2 (7 clonotypes each) contained a hydrophobic amino acid followed by Arg and a negatively charged or a polar residue (Asn or Gly), respectively. Motif 3 (3 clonotypes) was x-Arg-Gly. In 12 of these 17 rearrangements, the core sequence was followed by Tyr or Ser. By contrast, none of 31 different TCR-alpha rearrangements used by CD8+ spleen T cells encoded motifs 1 or 2, and only one encoded motif 3. Different TCR-beta rearrangements within individual lines also used homologous CDR3 sequences, but these sequences varied between lines. Skewed TCR-alpha-CDR3 usage by islet-derived CTLs was substantiated further by isolation of CTL clones transcribing highly homologous TCR-alpha, but different TCR-beta, rearrangements. These data suggest that CTLs recruited to pancreatic islets during spontaneous IDDM recognize a restricted set of beta-cell autoantigenic determinants.

Beta-cell-cytotoxic CD8+ T cells from nonobese diabetic mice use highly homologous T cell receptor alpha-chain CDR3 sequences

Insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a cell-mediated autoimmune process against pancreatic beta-cells. We have shown that beta-cell-cytotoxic CD8+ T cell clones can transfer IDDM to irradiated NOD mice if co-injected with nondiabetogenic CD4+ spleen T cells. To determine whether CTLs recruited to pancreatic islets recognize a restricted set of local Ags, we sequenced TCR-alpha and TCR-beta cDNA generated by anchor PCR from CD8+ CTL lines and clones derived from islets of 10 different NOD mice. These CTL lines were oligoclonal, but did not show skewed V alpha, V beta, J alpha, or J beta gene usage when compared with CD8+ spleen T cells. However, of the 26 different CTL-derived TCR-alpha sequences from all of these CTL lines and clones, 17 (65%) used one of three highly related, N region-encoded, CDR3 motifs. Motifs 1 and 2 (7 clonotypes each) contained a hydrophobic amino acid followed by Arg and a negatively charged or a polar residue (Asn or Gly), respectively. Motif 3 (3 clonotypes) was x-Arg-Gly. In 12 of these 17 rearrangements, the core sequence was followed by Tyr or Ser. By contrast, none of 31 different TCR-alpha rearrangements used by CD8+ spleen T cells encoded motifs 1 or 2, and only one encoded motif 3. Different TCR-beta rearrangements within individual lines also used homologous CDR3 sequences, but these sequences varied between lines. Skewed TCR-alpha-CDR3 usage by islet-derived CTLs was substantiated further by isolation of CTL clones transcribing highly homologous TCR-alpha, but different TCR-beta, rearrangements. These data suggest that CTLs recruited to pancreatic islets during spontaneous IDDM recognize a restricted set of beta-cell autoantigenic determinants.