Murine suppressor T cell clones specific for minor histocompatibility antigens express CD4, CD8, and alpha beta T cell receptor molecules.

We have been able to establish stable, minor histocompatibility antigen-specific, non-cytolytic, MHC-class II-restricted suppressor T cell clones and lines. These suppressor T cells rearrange, transcribe, and express alpha beta T cell receptor. An unusual feature of all our clones and lines is the co-expression of CD4 and CD8 molecules on their cell surface, a characteristic which may distinguish them from conventional helper and cytolytic T cells in this system. The fact that multiple, phenotypically and functionally identical cell lines were reproducibly obtained from this system indicates that antigen-specific down-regulation of immune functions in certain circumstances is mediated by T cells that are neither conventional cytolytic nor helper T cells.