Activation of Human B Lymphocytes after Immunization with Pneumococcal Polysaccharides

• Text
• PDF

Abstract

The in vivo and in vitro immune response after in vivo immunization with pneumococcal polysaccharides (PPS) has been analyzed in man. Substantial differences were noted in this system when compared with human responses to soluble protein antigens. Within 6 d after immunization, specific PPS antigen-binding cells (ABC), specific plaque-forming cells (PFC), and cells capable of spontaneously synthesizing in vitro large amounts of specific anti-PPS immunoglobulin (Ig) G. IgA, and lesser amounts of specific IgM appeared in the peripheral blood. The ABC, PFC, and the total amount of specific spontaneous antibody production followed nearly identical kinetics after immunization. Low doses of irradiation markedly inhibited spontaneous anti-PPS antibody production by lymphocytes obtained 7 or 8 d after immunization, suggesting a requirement for in vitro proliferation for full expression of antibody-secreting capability of these cells that are activated in vivo and are capable of spontaneous antibody production in vitro. Spontaneous secretion by B lymphocytes in vitro was independent of T cells, unmodified by the addition of T cell factors, and readily suppressible by pokeweed mitogen (PWM).

Authors

John K. Kehrl, Anthony S. Fauci