Abstract: | Regulation of IgE production by antigen in a primed murine splenic lymphocyte culture system was described. Maximum IgE antibody production was found to occur when cells were cultured in the absence of exogenously added antigen. A cells and T lymphocytes did not affect the production of anti-DNP IgE antibody. By using a hapten-carrier antigen system (DNP-EA) for priming mice in vivo, it was found that the production of anti-DNP IgE by spleen cells in vitro was inhibited by hapten when coupled to homologous (EA) or heterologous (BGG) carrier, and was not enhanced or inhibited by homologous carrier. Anti-DNP IgE antibody production by cultures depleted of macrophages or T lymphocytes was found to be as sensitive to the suppressive effects of hapten as was the IgE production by whole spleen cell cultures. Both IgM and IgG secondary anti-DNP PFC responses in vitro were enhanced by the presence of the homologous hapten-carrier or carrier alone. DNP-BGG had no effect on the anti-DNP IgM or IgG PFC responses of the cultures. These data suggest that endogenous production of antibody (IgM or IgG) was not responsible for the observed suppression of the IgE response in vitrol The experimental results presented indicate that the regulation of the IgE production by antigen in the primed mouse splenic lymphocyte cultures was a consequence of the direct interaction of hapten with IgE B cells. |