Yoshida N, Araguth M F
Parasite Immunol. 1987 May;9(3):389-93. doi: 10.1111/j.1365-3024.1987.tb00516.x.
Metacyclic trypomastigotes of Trypanosoma cruzi, derived either from triatomid vectors or axenic cultures, were found to be extensively lysed by sera of some non-Chagasic healthy individuals through activation of the alternative complement pathway. Antibodies to T. cruzi metacyclics were detected by direct agglutination test in normal human sera (NHS) containing trypanolytic activity. Absorption of lytic NHS with metacyclic trypomastigotes, but not with non pathogenic Herpetomonas samuelpessoai promastigotes, abolished the trypanolytic effect. Natural antibodies to trypomastigotes were not found in NHS devoid of trypanolytic activity. Precipitation of 131I-labelled metacyclic surface proteins with lytic NHS revealed as the major band a polypeptide with an apparent molecular weight of 75,000.
