Trypanosoma cruzi: involvement of IgG isotypes in the parasitemia control of mice immunized with parasite exoantigens of isoelectric point 4.5.

CERBAN F1, GRUPPI A, VOTTERO-CIMA E.

EXPERIMENTAL PARASITOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 1992 vol. 75 p. 137 - 137

0014-4894

n a previous work we demonstrated that Trypanosoma cruzi exoantigens of pI 4.5 (Ea 4.5), whose most important epitopes are glucidic, are able to induce a partially protective immune response in mice. To ascertain the involvement of antibody isotypes in this protection, we immunized mice with Ea 4.5 plus Bordetella pertussis as adjuvant. The analysis of immune response by skin test revealed the occurrence of specific immediate type hypersensitivity on Day 15 after the last immunization. By ELISA and using Ea 4.5 as antigen, specific IgG1 antibody was detected. When formaldehyde-fixed epimastigotes were used as antigen, binding of IgG1 and IgG2 was observed. Trypomastigotes incubated for 1 hr at 33 degrees C with the immune sera and then injected in normal syngeneic mice produced a significantly lower parasitemia than trypomastigotes incubated with the control sera. This capacity of anti-Ea 4.5 sera was resistant to 56 degrees C for 2 hr and was diminished after the absorption of immune