The role of antibodies in the regulation of delayed-type hypersensitivity.

The contribution of B cells and antibodies to the regulation of delayed-type hypersensitivity (DTH) was investigated in mice rendered B-cell-deficient by treatment with anti-mu antibodies. In normal rabbit immunoglobulin (Ig)-treated mice as well as normal mice, the intravenous injection of a large amount of keyhole limpet haemocyanin (KLH) suppressed DTH, and serum titres of the anti-KLH antibody were significantly elevated. However, in anti-mu-treated mice, the intravenous injection of a large amount of KLH could not induce either suppression of DTH or the elevation of anti-KLH antibody titres. The transfer of anti-KLH antibodies suppressed DTH in a H-2 non-restricted, probably Igh-restricted, way in anti-mu-treated mice. In addition, the transfer of anti-KLH antibodies induced effector-phase suppressor T cells whose phenotype was L3T4-, Lyt-2+. We concluded that antibodies play a significant role in the regulation of DTH.