Regulatory role of IgE-binding factors from rat T lymphocytes. V. Formation of IgE-potentiating factor by T lymphocytes from rats treated with Bordetella pertussis vaccine

An i.p. injection of Bordetella pertussis vaccine (BP) into rats induced the formation of soluble factors that had affinity for IgE (IgE-binding factors). The factor was detected in the serum of BP-treated animals 5 to 7 days after the treatment. Their circulating lymphocytes as well as spleen cells spontaneously released IgE-binding facfors in vitro. Essentially all IgE-binding factors in the serum of BP-treated rats and those released from their circulating lymphocytes had affinity for lentil lectin, and the ability to selectively potentiate an in vitro IgE response of DNP-OA primed cells to homologous antigen. The molecular size of IgE-potentiating factor was between 10,000 and 20,000, and was comparable to that formed by lymphocytes of rats infected with Nippostrongylus brasiliensis. Evidence was obtained that IgE-potentiating factor was derived from Fc(ε)R(+) T cells, with a T cell marker identified by monoclonal antibody W 3/25. Their production of IgE-potentiating factor may be the basis of the adjuvant effect of BP on the IgE response.