Investigation on antigen-specific T cell responses in type 2 diabetes mellitus patients

Objective To investigate the antigen-specific T cell functionality in type 2 diabetes mellitus patients.Methods Peripheral blood from 38 type 2 diabetes mellitus patients and 47 healthy controls(control group)were collected.The proportions of CD4^+and CD8^+ T cell as well as the ratio of CD4+/CD8 + were monitored by flow cytometry.Meanwhile,antigen-nonspecific and specific Th1 responses were compared between the two groups through detecting interferon(IFN)-γ,interleukin 2(IL-2),and tumor necrosis factor(TNF)-α producing cells upon propylene glycol monomethyl ether acetate(PMA)/ionomycine and epstein-barr virus(EBV)peptides stimulation,respectively followed by an intracellular cytokine staining.Results Compared to the control group,the proportion of CD4^+T cell and the ratio of CD4^+/CD8^+ were significantly increased in the type 2 diabetes mellitus group(P<0.05)whereas CD8+T cells exhibited no significant difference between the two groups.Antigen-nonspecific Th1 responses in type 2 diabetes mellitus patients were significantly decreased,demonstrated by lower percentages of IFN-γ,IL-2,and TNF-α producing CD4^+T cells when compared to the control group,while CD8^+T cells in the type 2 diabetes mellitus patients exhibited similar cytokine production patterns.However,when stimulated by EBV specific peptides,the percentages of IFN-γ,IL-2,and TNF-α producing CD8^+T cells were significantly higher in type 2 diabetes mellitus patients than those in the control group(P<0.05).Hb A1 C was positively correlated with the percentage of EBV-specific TNF-α producing CD8^+T cells(P<0.05).Conclusion In type 2 diabetes mellitus,the secretion capacity of CD4^+and CD8^+ T cell was significantly decreased and the antigen-specific responses represent the presence of an abnormal activated status,which indicates that chronic hyperglycemia may damage T cells function and aggravate chronic inflammation.