This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hanna, E. E. Articles by Watson, D. W. Search for Related Content PubMed PubMed Citation Articles by Hanna, E. E. Articles by Watson, D. W.

 Previous Article  |  Next Article 

J Bacteriol. 1968 January; 95(1): 14-21
Copyright © 1968 American Society for Microbiology. All Rights Reserved.

Host-Parasite Relationships Among Group A Streptococci IV. Suppression of Antibody Response by Streptococcal Pyrogenic Exotoxin

^a Department of Microbiology, University of Minnesota, Minneapolis, Minnesota 55455

ABSTRACT

In rabbits, purified streptococcal pyrogenic exotoxin, at 0.002 of the LD₅₀ dose, suppressed the antibody response to injected sheep erythrocytes. The antibody suppressed was determined by density gradient ultracentrifugal analysis to be of the 19S class. Background serum antibody (50% hemolytic units), as determined photometrically, correlated well with background antibody-forming spleen cells, as determined by the hemolytic-plaque technique. The exotoxin induced neither positive nor negative changes in background antibody levels, but suppressed the early secondary response to injected antigen. A comparison and control experiment showed that purified gram-negative bacterial endotoxin at identical protocol did not induce antibody suppression, but did induce the well-known adjuvant effect. Because streptococcal pyrogenic exotoxin is known to inhibit the phagocytic function of the reticuloendothelial system (RES), these data strongly support the concept that antigen is processed by cells of the RES before it evokes a secondary immune response. The results also demonstrated that streptococcal pyrogenic exotoxin may play a unique role in lowering the acquired defense of the host against infection. If the anamnestic immune response of the host is temporarily suppressed, then the host-parasite balance would be upset in favor of the parasite.

¹ Present address: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, Md. 20014.

This article has been cited by other articles:

• Bas, S, Scieux, C, Vischer, T L (2001). Male sex predominance in Chlamydia trachomatis sexually acquired reactive arthritis: are women more protected by anti-chlamydia antibodies?. Ann Rheum Dis 60: 605-611 [Abstract] [Full Text]