Objective To investigate the role of T cell and its subsets in the induction of insulitis and type 1 diabetes mellitus（T1DM）in BALB/c mice.Methods Autoimmune diabetes mellitus was developed by intraperitoneal injection of 40 mg/kg streptozotocin（STZ）daily for 5 consecutive days in BALB/c mice as sources of donor cells.Spleen cells from diabetic mice were then cultured for 7 days in the stimulation of interleukin-2（IL-2）to harvest diabetogenic T cells

which were subsequently transferred into normal BALB/c mice recipients.MTT

ELISA

and HE staining were used to analyze the lymphocyte proliferation

cytokine（IL-2

interferon-γ

IL-4

and IL-10）levels

and pathological changes in pancreatic islets.Results As few as 3×106 diabetogenic T cells successfully induced diabetes mellitus in recipients pretreated with STZ twice

whereas transfer of equal amount of normal splenocytes

T cell-depleted diabetogenic splenocytes

or diabetogenic CD4+ T cells alone in recipients receiving STZ twice pretreatment was proved not to induce diabetes mellitus either.A markedly increased lymphocyte proliferation

high levels of interferon-γ and IL-2 in the supernatants of diabetogenic T cells were observed.In addition

a markedly enhanced lymphocyte proliferation

a high level of interferon-γ secretion in serum

and numerous lymphocytes infiltration in pancreatic islets were detected in the diabetic mice induced by diabetogenic T cells transfer.Conclusions A novel T1DM murine model is established in STZ-pretreated BALB/c mice by adoptive transfer of diabetogenic T cells.CD4+ T cells with interferon-γ may promote the onset of diabetes mellitus.