Increased resistance to effector cell blockade in antibody-producing cells of NZB mice

Susceptibility of B lymphocytes fo 'effector cell blockade', i.e. in vitro inactivation of antibody-forming cells by specific antigen, was studied in NZB and C57BL/6 mice. Mice were immunized either with dinitrophenylated dextran (DNP-Dex) or DNP-keyhole limpet hemocyanin (DNP-KLH). It was shown that both direct and indirect anti-DNP plaque-forming cells (PFC) from older NZB mice were less affected by the preincubation with the corresponding antigen than those from age-matched C57BL/6 mice or young NZB mice. The increased resistance of B lymphocytes in aged NZB mice to the effector cell blockade may play a significant role for generation of autoantibody-forming cells in the presence of excess amounts of corresponding antigens.