Regulation of immunological disorders by invariant Vα19-Jα33 TCR-bearing cells.

We have previously shown that over-expression of the invariant Vα19-Jα33 TCR α transgene (Tg) using a natural TCR α promoter in mice induces the development of NK1.1+ T cells (Vα19 NKT cells) in lymphoid organs, including the liver and intestine. These cells produce different spectra of immunoregulatory cytokines such as IL-4, IL-10, IL-17, and IFN-γ depending on the duration and intensity of the invariant TCR stimulation. In this study, we examined the effects of over-expression of invariant Vα19-Jα33 TCR-bearing cells on disease progress in the models of immunological disorders. The introduction of invariant Vα19 TCR Tg into non-obese diabetic mice delayed the onset of the disease. In addition, delayed-type hypersensitivity (DTH) to sheep erythrocytes was suppressed in the Vα19 Tg mice. DTH was also suppressed in the wild type mice previously transferred with Vα19 Tg+ but not non-Tg cells. Thus, invariant Vα19 TCR-bearing cells are suggested to participate in the homeostasis of immunity to suppress disease progression resulting from Th1-immunity excess.