Antigenicity of type-specific pneumococcal polysaccharides in rats.
Hemagglutinating antibody responses of Lewis-Wistar and Sprague-Dawley rats to graded doses of type-specific pneumococcal polysaccharide were measured. Rats given a small dose (0.2 to 50 mug)of type 1 or 8 polysaccharide intraperitoneally developed type-specific hemagglutinating antibody. Rats given larger doses of polysaccharide (greater than or equal to200 mug) did not develop detectable hemagglutinating antibody, and they were unresponsive to a subsequence injection of a small (and normally antigenic) dose of polysaccharide. There was prolonged antigenemia in rats injected with a large dose of polysaccharide. There was prolonged antigenemia in rats injected with a large dose of polysaccharide, and the kinetics of antigen clearance in these animals resembled that reported for mice with polysaccharide immunological paralysis. These results indicate that a phenomenon resembling immunological paralysis with type-specific pneumococcal polysaccharides can be produced in rats.
D000818:Animals; D000907:Antibodies, Bacterial; D004305:Dose-Response Relationship, Drug; D006388:Hemagglutinins; D007108:Immune Tolerance; D008297:Male; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D051381:Rats; D013045:Species Specificity; D013296:Streptococcus pneumoniae / Q000276:immunology*
D000907:Antibodies, Bacterial; D006388:Hemagglutinins; D011135:Polysaccharides, Bacterial