The failure of nonresponder mice to develop IgG memory assessed by in vitro culture with an antigen-LPS conjugate.

A hen egg-white lysozyme-lipopolysaccharide complex (HEL-LPS) can stimulate an in vitro IgG response, but only from HEL-primed B lymphocytes; unprimed cells only produce an IgM response. These conditions were used to determine whether IgG memory B cells are cryptically induced in B10 nonresponder (H-2b) mice after an HEL injection protocol. The usual i.p. immunization that triggers IgG memory production in congenic responder strain mice fails to yield IgG in vitro from HEL-primed B10 spleen cells after stimulation with HEL-LPS. However, injection protocols immunogenic for B10 mice do engender IgG-memory cells. These results imply that the T helper cell population necessary for triggering B cells to the IgG memory stage cannot develop in the nonresponder mouse, presumably due to HEL-specific T suppressor cells.