Enumeration of polyclonal mitogen-responsive cells in different lymphoid tissues of the mouse.

The relative number of cells capable of responding to Con A, PHA and LPS in the spleen, blood, lymph node and Peyer's patches of CBA mice has been quantified by means of a cytological analysis technique. No difference has been found between Con A- and PHA-responsive cells in spleen and lymph node. The lymphoid tissues of T cell-deprived mice have a reduced content of PHA responsive cells, but LPS responsiveness is within normal limits. Pretreatment of peripheral lymphocyte populations with high concentrations of anti-O antiserum and complement abolishes the response of the treated cells to PHA, but not to LPS, whereas similar treatment with a cytotoxic anti-immunoglobulin serum, which has no effect on PHA-responsive cells, only partially reduces the response to LPS. The results for mitogen responsiveness are discussed with reference to other methods of quantifying T and B cells using cell-surface markers.