Antigen-sensitive spleen cells and the adjuvant activity of Bordetella pertussis

Abstract

In this study we determined at both the cellular and humoral level whether or not the primary immune response of mice can be significantly enhanced by administration of a bacterial adjuvant after the primary immunization with sheep erythrocytes. As compared to the immunization of mice with 8 × 106 sheep erythrocytes alone, the simultaneous injection of 3 × 109Bordetella pertussis cells and 8 × 106 sheep erythrocytes resulted in an accelerated and prolonged multiplication of hemolysin-forming spleen cells. The adjuvant effect was also documented by increased production of serum hemolysins. When the bacterial adjuvant was given 6, 12, or 24 h after the primary antigenic stimulus, however, neither increased plaque counts nor enhanced serum hemolysin titers were detectable. These findings agree with the concept that B. pertussis cells cause multiplication of antigen-sensitive target cells or affect the initial stages of differentiation of these cells.