Antigens of Cryptosporidium sporozoites recognized by immune sera of infected animals and humans.
The humoral response of humans, calves, and horses to Cryptosporidium sporozoite antigens was evaluated using a western blot technique. Sera from calves, humans, and horses were obtained at various times following the detection of infection. Sera were reacted with detergent-solubilized, sodium dodecyl sulfate polyacrylamide gel-electrophoresed (SDS-PAGE) sporozoite antigens. The number of antigens recognized by immune sera from humans and animals increased with time postinfection. A 20-kDa antigen appears to be a major sporozoite surface determinant labeled via membrane protein biotinylation and recognized by mouse monoclonal antibodies using indirect immunofluorescence and western blotting. Detectable recognition of the 20-kDa band occurred in 3-wk postinfection (PI) sera from all species tested. Reactivity to the 20-kDa band diminished significantly in sera 5 mo PI or longer from infected humans with no known recurrence of cryptosporidial diarrhea. In contrast, 12-mo PI sera from an individual constantly exposed to oocysts under working conditions was as strongly reactive as the 3-wk convalescent sera. Serum reactivity to the 20-kDa antigen appears to be a good indicator of exposure to Cryptosporidium.
Mead
J R
JR
Department of Microbiology, University of Arizona, Tucson 85721.
Arrowood
M J
MJ
Sterling
C R
CR
D000818:Animals; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan / Q000032:analysis* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology; D003044:Coccidia / Q000276:immunology*; D003457:Cryptosporidiosis / Q000276:immunology*; D003458:Cryptosporidium / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D006734:Horse Diseases / Q000276:immunology; D006736:Horses; D006801:Humans; D007118:Immunoassay; D010455:Peptides / Q000276:immunology
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D010455:Peptides