Thrombospondin-1 interacts with Trypanosoma cruzi surface calreticulin to enhance cellular infection

• Published in: PloS one Vol. 7; no. 7; p. e40614
• Main Authors: Johnson, Candice A, Kleshchenko, Yulia Y, Ikejiani, Adaeze O, Udoko, Aniekanabasi N, Cardenas, Tatiana C, Pratap, Siddharth, Duquette, Mark A, Lima, Maria F, Lawler, Jack, Villalta, Fernando, Nde, Pius N
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11.07.2012; Public Library of Science (PLoS)
• Subjects: Animals; Antibodies; Biology; Calreticulin; Calreticulin - isolation & purification; Calreticulin - metabolism; Cell adhesion & migration; Cell Membrane - metabolism; Chagas disease; Chagas Disease - parasitology; Chagas Disease - pathology; Cloning; Cloning, Molecular; Embryo fibroblasts; Extracellular matrix; Fibroblasts; Health aspects; Immunology; Immunoprecipitation; Infection; Infections; Leishmania donovani; Life Cycle Stages; Mass spectrometry; Mass spectroscopy; Medicine; Mice; Mice, Inbred C57BL; Molecular biology; Motility; Parasites; Pathogenesis; Pathology; Protein Binding; Proteins; Protozoa; Staining and Labeling; Sterols; Thrombospondin; Thrombospondin 1 - chemistry; Thrombospondin 1 - metabolism; Tropical diseases; Trypanosoma cruzi; Trypanosoma cruzi - cytology; Trypanosoma cruzi - growth & development; Trypanosoma cruzi - metabolism; Trypanosoma cruzi - physiology; Trypomastigotes; Vector-borne diseases; Virulence (Microbiology); United States > US; Massachusetts; Tennessee; Nashville Tennessee
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0040614

Trypanosoma cruzi causes Chagas disease, which is a neglected tropical disease that produces severe pathology and mortality. The mechanisms by which the parasite invades cells are not well elucidated. We recently reported that T. cruzi up-regulates the expression of thrombospondin-1 (TSP-1) to enhance the process of cellular invasion. Here we characterize a novel TSP-1 interaction with T. cruzi that enhances cellular infection. We show that labeled TSP-1 interacts specifically with the surface of T. cruzi trypomastigotes. We used TSP-1 to pull down interacting parasite surface proteins that were identified by mass spectrometry. We also show that full length TSP-1 and the N-terminal domain of TSP-1 (NTSP) interact with T. cruzi surface calreticulin (TcCRT) and other surface proteins. Pre-exposure of recombinant NTSP or TSP-1 to T. cruzi significantly enhances cellular infection of wild type mouse embryo fibroblasts (MEF) compared to the C-terminal domain of TSP-1, E3T3C1. In addition, blocking TcCRT with antibodies significantly inhibits the enhancement of cellular infection mediated by the TcCRT-TSP-1 interaction. Taken together, our findings indicate that TSP-1 interacts with TcCRT on the surface of T. cruzi through the NTSP domain and that this interaction enhances cellular infection. Thus surface TcCRT is a virulent factor that enhances the pathogenesis of T. cruzi infection through TSP-1, which is up-regulated by the parasite.