I-J and mechanism of immunosuppression.

I-J has found to be an inducible isomorphic molecule expressed on class II-restricted T cells. It undergoes a systematic adaptive change in radiation done marrow chimeras according to the environmental major histocompatibility complex (MHC). Recent biochemical studies demonstrated that I-J id a homodimer of MW 84,000–90,000 composed of 42,000–46,000 MW glycopeptide subunits. The molecule is different from class II-restricted T-cell receptor, class II antigens or putative mouse CD28. The ligation of I-J molecules anti-I-J result in the suppression of T-cell responses by the inhibition of early signal transduction through antigen recognition. [ABSTRACT FROM AUTHOR]