Biological properties of rabbit antibodies to a surface antigen of Rickettsia rickettsii.
Because of the potential significance of external components of the obligate intracellular parasite Rickettsia rickettsii in host-parasite interactions, we have begun the first phase of a study to isolate and characterize surface antigens of this organism. An antiserum to a rickettsial surface component was obtained from rabbits inoculated with immune precipitates prepared by crossed immunoelectrophoresis of Triton X-100 extracts of R. rickettsii strain R. This antiserum (i) protected guinea pigs inoculated with 10,000 guinea pig 50% infectious doses of R. rickettsii against fever, (ii) prevented death of mice challenged with 2 50% lethal doses of R. rickettsii, and (iii) reacted in the microimmunofluorescence test with 9 of 13 spotted fever group serotypes tested. The location of this antigen on the rickettsial surface was demonstrated by immunoelectron microscopy with ferritin-labeled antibodies.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology*; D006168:Guinea Pigs; D007106:Immune Sera / Q000032:analysis / Q000276:immunology; D007116:Immunization, Passive; D007123:Immunoelectrophoresis, Two-Dimensional; D008297:Male; D051379:Mice; D011817:Rabbits; D012284:Rickettsia rickettsii / Q000276:immunology / Q000648:ultrastructure; D012373:Rocky Mountain Spotted Fever / Q000276:immunology* / Q000628:therapy; D012703:Serotyping
D000907:Antibodies, Bacterial; D000954:Antigens, Surface; D007106:Immune Sera