Generation of specific helper cells and suppressor cells in vitro for the IgE and IgG antibody responses

Normal splenic lymphocytes from BDF₁ mice were cultured on ovalbumin (OA) bearing syngeneic peritoneal adherent cells for 5 days and their subsequent helper function was tested by an adoptive transfer technique. Lymphocytes harvested from the culture were mixed with DNP-KLH primed spleen cells and transferred into irradiated syngeneic mice followed by challenge with DNP-OA. The results showed that the cultured lymphocytes had helper function for both IgE and IgG anti DNP antibody responses. Depletion of mast cells and T cells in the peritoneal adherent cell preparations did not affect the generation of helper cells in the culture. The helper function of the cultured lymphocytes was abolished by the treatment with anti theta antiserum and complement and was specific for ovalbumin. The OA specific helper T cells were generated in vitro by the culture of a T cell rich fraction of normal spleen on T cell depleted OA bearing peritoneal cells. If the normal splenic lymphocytes or T cell rich fraction were cultured with 10 μg/ml of OA in the absence of macrophages, cultured lymphocytes lacked helper function. The transfer of splenic lymphocytes or splenic T cells cultured with soluble OA to normal non irradiated mice, however, suppressed both IgG and IgE antibody responses of the recipients to subsequent immunization with DNP-OA. The suppressor cells were sensitive to anti theta antiserum and complement and their activity was specific for OA. The cultured cells transferred into normal mice did not suppress anti hapten antibody response to DNP-KLH. Normal lymphocytes cultured on OA bearing macrophages which had helper function in adoptive transfer experiments failed to suppress antibody response of non irradiated recipients to DNP-OA. The results indicate that OA bearing macrophages primed T cells and generated helper T cells, whereas the culture of normal lymphocytes with soluble OA in the absence of macrophages generated suppressor T cells.