title: The immune response to pneumococcal polysaccharide type III is followed by increased production of an antibody antifactor.
abstract: The study shows that serum from pneumococcal polysaccharide type III (SSSIII)-immunized and nonimmunized mice that has been absorbed until devoid of anti-SSSIII antibodies inhibits anti-SSSIII plaque-forming cells (PFC) but not antisheep red blood PFC in antibody plaque assay. A large fraction of the inhibitions activity can be absorbed by and eluted from anti-SSSIII-Sepharose, but not normal mouse serum-Sepharose. It has low or no affinity for protein A and concanavalin A. The titre of the inhibitor increases with repeated immunizations and inhibits the anti-SSSIII PFC of rats or mice of different allotypes. On the basis of these characteristics, I classify the inhibitor as an anti-idiotypic nonimmunoglobulin factor directed against a common determinant of anti-SSSIII antibodies of mouse and rat, with an immuno-regulatory function.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000037:antagonists & inhibitors; D000917:Antibody Formation; D002850:Chromatography, Gel; D005260:Female; D006462:Hemolytic Plaque Technique; D007114:Immunization; D007163:Immunosorbent Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D051381:Rats; D012685:Sepharose; D013296:Streptococcus pneumoniae; D013997:Time Factors
chemical_list: D000906:Antibodies; D011135:Polysaccharides, Bacterial; C026604:pneumococcal polysaccharide, type III; D012685:Sepharose