HLA-DR3 mediated CD4 T cell response against GAD65 in type 1 diabetes patients.

AIM: We planned this study to identify diabetogenic glutamic acid decarboxylase (GAD65) peptides possibly responsible for human leucocyte antigen (HLA)-DR3/DQ2-mediated activation of GAD65-specific CD4 T cells in type 1 diabetes (T1D). METHODS: Top 30 GAD65 peptides, found to strongly bind in silico with HLA-DR3/DQ2 molecules, were selected and grouped into four pools. The peptides were used to stimulate CD4 T cells of study subjects in 16-h peripheral blood mononuclear cell culture. CD4 T cells' stimulation in terms of interferon-gamma (IFN-γ), interleukin (IL)-17, tumor necrosis factor-alpha (TNF-α), and IL-10 expression was analyzed using flow cytometry. RESULTS: Although all four GAD65 peptide pools (PP1-4) resulted in significantly higher expression of IFN-γ by CD4 T cells (p = .003, p < .0001, p = .026, and p = .002, respectively), only pool 2 showed significant increase in IL-17 expression (p < .0001) in T1D patients vs healthy controls. Interpeptide group comparison for immunogenicity revealed significantly higher IFN-γ and IL-17 expressions and significantly lower IL-10 expression for PP2 compared to other groups (p < .0001, p = .02, and p = .04, respectively) in patients but not in controls. Further, group 2 peptides resulted in significant increase in CD4 T cells' expression of IFN-γ and IL-17 (p = .002 for both) and significant decrease in IL-10 (p = .04) in HLA-DRB1*03-DQA1*05-DQB1*02+ patients vs HLA-DRB1*03-DQA1*05-DQB1*02+ controls. The CD4 T cells' expression of IL-17 was significantly higher (p = .03) in recently diagnosed vs long-standing HLA-DRB1*03-DQA1*05-DQB1*02+ T1D patients. CONCLUSION: GAD65 peptides, particularly those belonging to PP2, induced CD4 T cells to express IFN-γ and IL-17 cytokines in T1D patients, suggesting that group 2 peptides possibly presented by HLA-DR3 molecule to CD4 T cells shift immune balance toward inflammatory phenotype in patients.

Therapies for Type 1 Diabetes: Is a Cure Possible?

The current standard method for type 1 diabetes (T1D) management majorly focuses on controlling blood glucose levels with exogeneous insulin administration. Recent developments have focused on finding ways to predict and prevent the development of T1D, as well as finding a curative therapy for T1D. Such developments include ß-cell replacement therapy by islet transplantation, non-insulin adjunct therapy, gene and stem cell-based therapies, immunotherapy, and automated treatment with an artificial pancreas. In recent years, non-traditional alternative therapy has also become a popular treatment option for T1D. This review discusses the various therapeutic options for T1D currently under various stages of development, the challenges associated with the present strategies, and their potential to eventually change the way T1D is treated.

Differential HLA Association of GAD65 and IA2 Autoantibodies in North Indian Type 1 Diabetes Patients.

The human leucocyte antigen (HLA) association with type 1 diabetes (T1D) is well known but there are limited studies investigating the association between ß-cell autoantibodies and HLA genes. We evaluated the prevalence of GAD65 and IA-2 autoantibodies (GADA and IA2A) in 252 T1D patients from North India and investigated the genetic association of GADA and IA2A with HLA class I and class II genes/haplotypes. GADA and IA2A were detected in 50.79% and 15.87% of T1D patients, respectively, while only 8.73% had both GADA and IA2A. HLA-DRB1∗03 was observed to be significantly higher in GADA+ T1D patients as compared to GADA- (91.41% vs. 66.13%, Bonferroni-corrected P (P c) = 1.11 × 10-5; OR = 5.45; 95% CI: 2.67-11.08). Similarly, HLA-DQB1∗02 was found to be significantly increased in GADA+ patients (94.53%, P c = 2.19 × 10-5; OR = 6.27; 95% CI: 2.7-14.49) as compared to GADA- (73.39%). The frequencies of HLA-DRB1∗04 and DQB1∗03 were increased in IA2A+ patients (45.0% and 52.5%, respectively) as compared to that in IA2A- (25.94% and 33.96%, respectively). Further, the frequency of DRB1∗03-DQB1∗02 haplotype was found to be significantly increased in GADA+ T1D patients as compared to GADA- (60.55% vs. 41.94%, P = 3.94 × 10-5; OR = 2.13; 95%CI = 1.49-3.03). Similarly, HLA-DRB1∗04-DQB1∗03 haplotype was found to be significantly increased in IA2A+ T1D patients compared to IA2A- patients (22.5% vs. 12.97%; P = 0.041; OR = 1.95; 95%CI = 1.08-3.52). None of the HLA class I genes (HLA-A, B, and Cw) was found to be associated with GADA or IA2A in people with T1D. Our findings suggest that HLA-DRB1∗03/DQB1∗02 and HLA-DRB1∗04/DQB1∗03 might play an important role in the development of GADA and IA2A, respectively.

Diverse human leukocyte antigen association of type 1 diabetes in north India.

BACKGROUND: Type 1 diabetes (T1D) is a complex disease, with involvement of various susceptibility genes. Human leukocyte antigen (HLA) on chromosome 6p21 is major susceptibility region. This study examined genetic association of HLA genes with T1D. METHODS: The study recruited 259 T1D patients and 706 controls from north India. PCR-SSP and LiPA were used to type HLA Class I and II alleles. RESULTS: At HLA Class I locus, HLA-A*02, A*26, B*08 and B*50 were significantly increased in patients vs controls (39.8% vs 28.9% [Bonferroni-corrected P {Pc } = 0.032], 24.7% vs 9.6% [Pc = 4.83 × 10-8 ], 37.2% vs 15.7% [Pc = 1.92 × 10-9 ], and 19.4% vs 5.5% [Pc = 4.62 × 10-9 ], respectively). Similarly, in Class II region, DRB1*03 showed a strong positive association with T1D (78.7% vs 17.5% in controls; P = 1.02 × 10-9 ). Association of DRB1*04 with T1D (28.3% vs 15.5% in controls; Pc = 3.86 × 10-4 ) was not independent of DRB1*03. Negative associations were found between T1D and DRB1*07, *11, *13, and *15 (13.8% vs 26.1% in controls [Pc = 0.00175], 3.9% vs 16.9% in controls [Pc = 6.55× 10-6 ], 5.5% vs 21.6% in controls [Pc = 2.51 × 10-7 ], and 16.9% vs 43.9% in controls [Pc = 9.94× 10-10 ], respectively). Compared with controls, patients had significantly higher haplotype frequencies of A*26-B*08-DRB1*03-DQA1*05-DQB1*02 (10.43% vs 1.96%; P = 7.62 × 10-11 ), A*02-B*50-DRB1*03-DQA1*05-DQB1*02 (6.1% vs 0.71%; P = 2.19 × 10-10 ), A*24-B*08-DRB1*03-DQA1*05-DQB1*02 (4.72% vs 0.8%; P = 5.4 × 10-7 ), A*02-B*08-DRB1*03-DQA1*05-DQB1*02 (2.36% vs 0.18%; P = 3.6 × 10-5 ), and A*33-B*58-DRB1*03-DQA1*05-DQB1*02 (4.33% vs 1.25%; P = 0.00019). CONCLUSIONS: In north India, T1D is independently associated only with HLA-DRB1*03 haplotypes, and is negatively associated with DRB1*07, *11, *13, and *15.