Trypanosoma cruzi: effect of protein kinase inhibitors and cytoskeletal protein organization and expression on host cell invasion by amastigotes and metacyclic trypomastigotes.
Although trypomastigotes are regarded as the classic infective forms of T. cruzi, amastigotes generated extracellularly or released from infected cells during lysis may circulate and infect other cells. We have compared the infectivity of metacyclic trypomastigotes and extracellular amastigotes toward HeLa and Vero cells and observed that amastigotes were capable of invading both HeLa and Vero cells to a much higher degree than the corresponding metacyclic forms. Second, cell microfilament or microtubule disruption inhibited amastigote but not trypomastigote entry. Third, cells with altered expression in cytoskeletal components (ABP or gelsolin) internalize amastigotes and trypomastigotes with highly contrasting fashion. Fourth, protein kinase inhibitors such as genistein and staurosporine affect the internalization of amastigotes and trypomastigotes in a host-cell-dependent manner. Our results suggest that extracellular amastigotes and metacyclic trypomastigotes utilize mechanisms to invade host cells with particular features for each T. cruzi form and for each host cell. When internalized, both forms associate to lysosomes of HeLa cells.
Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Botucatu, 862, 6th floor, São Paulo, SP, 04023-062, Brazil.
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Procópio
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da Silva
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Cunningham
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Mortara
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D000818:Animals; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins / Q000096:biosynthesis / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D018260:Gelsolin / Q000096:biosynthesis; D019833:Genistein / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D008545:Melanoma; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics; D008870:Microtubules / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D047428:Protein Kinase Inhibitors; D019311:Staurosporine / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000472:pathogenicity* / Q000502:physiology*; D014407:Tumor Cells, Cultured; D014709:Vero Cells
D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D018260:Gelsolin; D008840:Microfilament Proteins; D047428:Protein Kinase Inhibitors; D019833:Genistein; D019311:Staurosporine