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Binding of antibody and resistance to lysis of trypomastigotes of Trypanosoma cruzi
Author(s) -
JACOBSON KYM C.,
FLETCHER ROBERT C.,
KUHN RAYMOND E.
Publication year - 1992
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/j.1365-3024.1992.tb00001.x
Subject(s) - trypanosoma cruzi , lysis , biology , antibody , propidium iodide , complement system , kinetoplastida , population , alternative complement pathway , microbiology and biotechnology , immunology , parasite hosting , programmed cell death , biochemistry , apoptosis , medicine , environmental health , world wide web , computer science
Summary Epimastigote forms of Trypanosoma cruzi are readily lysed by complement via the alternative pathway. Neither fibroblast‐derived trypomastigotes nor blood‐form trypomastigotes are lysed by complement alone and few (less than 30% of the Brazil strain) are lysed in the presence of parasite‐specific antibody and complement. The mechanism by which trypomastigotes resist antibody‐dependent, complement‐mediated lysis is not clearly understood. In the present study, we have utilized flow cytometric analysis to examine the binding of parasite‐specific antibody to epimastigotes, fibroblast‐derived trypomastigotes and blood‐form trypomastigotes of a Brazil strain of T. cruzi . We also determined the extent of lysis of these parasites in the presence of complement utilizing propidium iodide to determine cell death. It was found that all epimastigotes bind approximately the same amount of antibody but that there are subpopulations of trypomastigotes which bind antibody to varying degrees. When these subpopulations were sorted, and treated with complement, lysis was only minimally increased in the population of parasites which bound significantly greater amounts of antibody.