Selective removal of T cell function from mouse lymphocyte suspensions by treatment with normal guinea pig serum

Treatment of murine spleen cells with normal guinea pig serum selectively abrogated responsiveness of these cells to the T cell mitogens PHA or Con A, but failed to affect responses to LPS, i.e., a B cell-specific mitogen. Although pretreatment with GPS inhibited the in vitro immune response of mouse splenocytes to SRBC, responses were normal after restoration with T cells only, indicating that B cells had been spared by GPS. Consistent with these results, incubation with GPS resulted in the loss of reactivity of mouse lymphoid cells in MLC as well as CML systems, both of which test for T cell activities. Furthermore, parental spleen cells treated with GPS were no longer capable of inducing a GVH reaction in F1 hybrids. When compared, the effects of GPS and anti-Thy-1.2 antibodies plus C were found to be comparable. These results indicate that GPS can selectively remove a number of T cell functions from heterogeneous murine lymphoid cell suspensions. Since spleen macrophages were insensitive to GPS cytotoxicity, lack of T cell function is not likely to be due to depletion of these accessory cells.