Self-reactive T cells. V. T cell-mediated suppression of B cell responsiveness to LPS.

The intravenous injection of polyclonally activated lymphoblasts elicited a proliferative T cell reaction in the spleens of syngeneic recipient mice. In the non-fractionated cell populations obtained from these spleens 6 days after lymphoblast transfer, the LPS-induced proliferation and differentiation of B cells in vitro was suppressed. This suppressive effect was mediated by T cells, as i) treatment with anti-Thy-1 antiserum plus complement restored responsiveness of B cells to LPS in the spleen cell population that had responded in vivo to a syngeneic lymphoblast graft, and ii) the responsiveness of B cells to LPS was not impaired in non-fractionated spleen cell populations of nu/nu mice injected with syngeneic lymphoblasts. The relationship of this nonspecific T suppressor cell activity to the previously described non-specific T helper cell activity for B cell activation is discussed.