Next-generation targeted sequencing of HLA-DRB1 and HLA-DRB3, -DRB4, and -DRB5 (abbreviated as DRB345) provides high resolution of functional variant positions to investigate their associations with type 1 diabetes risk and with autoantibodies against insulin (IAA), GAD65 (GADA), IA-2 (IA-2A), and ZnT8 (ZnT8A).
Furthermore, T cells that recognized this peptide in the context of DRB4 were present at significantly higher frequencies in patients with T1D than in healthy controls, implicating this as a disease-relevant specificity that may contribute to the breakdown of β cell tolerance in genetically susceptible individuals.
DRB4*01:03:01 was strongly associated with type 1 diabetes (P = 10(-36)), yet its association was extensively affected by DRB1 alleles from protective (DRB1*04:03:01) to high (DRB1*04:01:01) risk, but its association with DRB1*04:05:01 decreased the risk.
Besides, the hub genes in PPI network of cluster 5 were identified, containing FOS, pro-platelet basic protein (PPBP), interleukin 8 (IL8), formyl peptide receptor-like 2 (FPR2) and platelet factor 4 (PF4).HLA-DQA1, HLA-DRB4, ITGB3 and KLRF1 might be targets for treatment of T1D, and 5 hub proteins, FOS, PPBP, IL8, FPR2 and PF4, were likely to be new markers for diagnosis of T1D.