Role of CD40-dependent signal in induction of recombinase RAG-1 expression in peripheral T cells of patients with autoimmune diabetes mellitus.

We studied the mechanisms of induction of recombinase activity in peripheral T cells of patients with autoimmune type 1 diabetes mellitus. It was shown that the presence of CD40 on T cell membrane (not typical of these cells) is crucial for this process: expression of recombinase RAG-1 in diabetic patients was detected primarily in αβTCR(+)CD40(+) lymphocytes; targeted CD40-dependent activation of intact T cells in vitro increases, while blockade of CD40 signal in the culture of stimulated T cells abolishes recombinase expression.