T-cell regulation of antibody responses: demonstration of allotype-specific helper T cells and their specific removal by suppressor T cells.

Abstract

Allotype suppressor T [thymus-derived] cells (Ts) generated in SJL .times. BALB/c mice specifically suppress production of antibodies marked with the Ig [immunoglobulin]-1b allotype. Allotype Ts suppress by specifically removing helper T cell (Th) activity required to facilitate differentiation and expansion of B [bone marrow-derived] cells to Ig-1b antibody-forming cells. Ts and Th belong to different T-cell subclasses as defined by Ly surface antigens. Ts are Ly2+Lyl-, and thus belong to the same subclass as cytotoxic precursor and effector cells; Th are Ly1+Ly2- cells, and thus belong to the subclass containing cells which can exert helper functions and initiate delayed hypersensitivity reactions. Placing these cells in these 2 subclasses shows that Th are different from Ts, and they apparently play different roles in regulating antibody respones. The difference in these roles is defined by the evidence presented here showing that Ts attack Th and regulate the antibody response by specifically regulating the availability of Th activity. In allotype suppressed mice, Ts which suppress Ig-1b antibody production have completely removed the Th activity capable of helping Ig-1b B cells without impairing Th activity which helps other IgG B cells. Allotype-specific Th for Ig-1b cells (Ig-1b Th) probably exist. Ig-1b cells require such help by showing that carrier-primed spleen cells from Iga/Iga congenic hybrids help Ig-1a B cells from hapten-primed Igb/Iga donors. but do not help Ig-1b B cells from the same donor in the same adoptive recipient.