Suppressor cells in spleens from "nude" mice: their effect on the mitogenic response of B lymphocytes.

A cell population recovered after velocity sedimentation fractionation of "nude" but not haired mouse spleen cells suppressed the response of spleen cells from both "nude" and haired mice to the B cell mitogen, LPS. The suppressor activity of these cells was abrogated by treatment with anti-theta antiserum and complement but not by treatment with the same antiserum preabsorbed with mouse brain. It is possible that these suppressor cells come from the pool of T cell precursors known to be present in "nude" bone marrow and spleen, and that they do not require thymic influence in order to perform the suppressor function.