The manner by which Trypanosoma cruzi interact with mammalian cells was studied in an in vitro tissue culture system. T. cruzi (Tulahuen strain) grown in modified Bonne and Parent (1962) medium were exposed to mouse peritoneal macrophages of L cells grown in monolayers at various multiplicities for periods up to 4 hr. At each 1/ hr interval, the cells were fixed in situ for electron microscopy. It was found that trypanosomes actively penetrated the L cells after initially fusing with the L cell plasma membrane. They always came to reside in the cytoplasm of the L cell and subsequently killed the host cell. Unstimulated macrophages exposed to T. cruzi at a ratio of 1:1 actively phagocytyzed the hemoflagellates and usually destroyed them within phagocytic vacuoles. By 24 hr no flagellates could be detected even if the cultures were not washed out at 4 hr. Infection carried out at a 10:1 parasite to unstimulated macrophage ratio resulted in destruction of the macrophages. Similar experiments carried out with BCC stimulated and primed macrophages revealed that the macrophages could control a 10:1 infection. Parallel in vivo experiments confirmed the role of macrophages in mouse T. cruzi infection.
|Original language||English (US)|
|Pages (from-to)||No. 111|
|Journal||American Journal of Pathology|
|State||Published - Jan 1 1975|
ASJC Scopus subject areas
- Pathology and Forensic Medicine