Induction of suppression and help during in vitro immunization of mouse spleen cells.

Both specific and non-specific suppressor cells are induced during the in vitro culture of mouse spleen cells in Mishell-Dutton-type cultures. The induction of T cells capable of providing helper activity does not require the presence of antigen during the culture period. In a mixture of helper and suppressor cells, as generated during the culture of spleen cells in the presence or absence of antigen, suppression is dominant if tested on normal spleen cells. This same cell mixture can reveal potent T-cell help if added in low numbers to T-cell depleted B cells in the presence of antigen. Partitioning of this cell mixture in a microculture system reveals potent T-cell help. Up to 1/600 recovered viable cultured mouse spleen cells can provide T-cell help for an anti-SRBC response. Evidence points to a coupled induction of non-specific help and suppression.