Alterations in the Antibody Response to Bovine Serum Albumin by Capsular Polysaccharide of <i>Klebsiella Pneumoniae</i>

Abstract

Abstract Immunologic paralysis was induced in mice by administration of large amounts of the capsular polysaccharide of Klebsiella pneumoniae (CPS-K). When a paralyzing dose of CPS-K was injected into mice 3 to 30 days before immunization with bovine serum albumin (BSA)-Freund's adjuvant complex, the immune response of mice to BSA was markedly depressed. Conversely, when a paralyzing dose of CPS-K was injected simultaneously with or 3 days after immunization with BSA-Freund's adjuvant complex, the immune response to BSA was enhanced. Paralyzing doses of CPS-K had a marked adjuvant effect on antibody formation to BSA, which is a weak immunogen when administered without any adjuvant. The adjuvant effect of CPS-K was most marked when it was administered simultaneously with BSA. In mice paralyzed with CPS-K serum γ globulin, splenic weight and phagocytic activity of the reticuloendothelial system increased markedly.