Regulation of Antibody Response in Different Immunoglobulin Classes

Abstract

Selective suppression of anti-DNP IgE antibody response by DNP-Tbc-primed T cells was studied by using the in vitro culture system of murine spleen cells. The addition of DNP-Tbc-primed cells to DNP-OA-primed cells suppressed the in vitro production of anti-DNP IgE antibody response induced with DNP-OA without any effect on anti-DNP IgG antibody response. The addition of DNP-MGG-, DNP-KLH-, or DNP-Asc-primed cells to DNP-OA-primed cells did not show any suppressive effect on anti-DNP IgE antibody response. Depletion of T cells by anti-ϑ treatment abolished the suppressor activity of DNP-Tbc-primed cells, whereas depletion of B cells by anti-Ig-column did not affect the suppressor activity. The suppressor activity of DNP-Tbc-primed cells was dose-dependent and radiosensitive. Cell-free supernatants (CFS) from the culture of DNP-Tbc-primed cells with DNP-HSA-pulsed macrophages or DNP-HSA-coupled Sepharose beads showed the suppressor activity on anti-DNP IgE antibody response of DNP-OA-primed cells. CFS did not show any effect on IgG response. The suppressor activity of CFS was not absorbed with DNP-HSA- or anti-Ig-coupled Sepharose immunoadsorbent, indicating that the IgE class-specific suppressor factor is not antigen-specific and does not have Ig-determinants.