Thrombospondin-1 interacts with Trypanosoma cruzi surface calreticulin to enhance cellular infection.
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.
Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, United States of America.
Candice A
CA
Johnson
Yulia Y
YY
Kleshchenko
Adaeze O
AO
Ikejiani
Aniekanabasi N
AN
Udoko
Tatiana C
TC
Cardenas
Siddharth
S
Pratap
Mark A
MA
Duquette
Maria F
MF
Lima
Jack
J
Lawler
Fernando
F
Villalta
Pius N
PN
Nde
D000818:Animals; D037282:Calreticulin / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D014355:Chagas Disease / Q000469:parasitology* / Q000473:pathology*; D003001:Cloning, Molecular; D047468:Immunoprecipitation; D008018:Life Cycle Stages; D051379:Mice; D008810:Mice, Inbred C57BL; D011485:Protein Binding; D013194:Staining and Labeling; D019700:Thrombospondin 1 / Q000737:chemistry / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology
D037282:Calreticulin; D019700:Thrombospondin 1