Isotype determination of anti-Trypanosoma cruzi antibody in murine Chagas' disease.
Isotypic analysis of anti-parasite humoral responses of C57B1/6 and C3H (He) mice surviving acute Trypanosoma cruzi infection showed that both mouse strains demonstrate IgG1, IgG2a, IgG2b, and IgM enzyme-linked immunosorbent assay titers from days 21 to 300 of infection. Using the western blot technique to determine the antigen specificity of the isotypic responses, 100-day infected C3H mice showed strong IgG1, IgG2a, and IgG2b responses to many antigens, whereas C57B1/6 mice showed weak responses to fewer antigens. Isotype western blots showed that reactivity to the T. cruzi antigen of 75-77 kDa is present in the humoral response of day 21-infected mice that will survive and missing in those that will not survive. In general, surviving immunized C3H mice respond with IgG1, IgG2a, and IgG2b reactions to the 75-77-kDa and other antigens, whereas resistant B6 mice concentrate their anti-T. cruzi response in the IgG2b isotype to the 75-77-kDa antigen. Perhaps induction of ineffective antibody responses to nonprotective antigens is beneficial to the parasite and detrimental to the host.
Rowland
E C
EC
Department of Zoological and Biomedical Sciences, Ohio University, Athens 45701.
Mikhail
K S
KS
McCormick
T S
TS
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D015153:Blotting, Western; D014355:Chagas Disease / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D014349:Trypanosoma cruzi / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000939:Epitopes; D007074:Immunoglobulin G; D007075:Immunoglobulin M