Trypanosoma cruzi: phagolysosomal fusion after invasion into non professional phagocytic cells.

Parasite-containing endocytic vacuoles are formed during the process of in vitro interiorization of the trypomastigote forms of Trypanosoma cruzi by primary culture of mouse fibroblasts, heart and skeletal muscle cells. Fusion of these vacuoles with host cell lysosomes takes place. The process of T. cruzi-muscle cell interaction was analysed by ultrastructural cytochemistry. Two lysosomal enzymes, acid phosphatase and aryl sulphatase and the fusion of peroxidase-labeled secondary lysosomes with the parasitophorus vacuoles were studied. These finding indicate that the basic mechanism of interaction of T. cruzi with the so called non phagocytic cells is similar to that which occurs with phagocytic cells.