Stable RNA interference of host thrombospondin‐1 blocks Trypanosoma cruzi infection

Abstract
Interactions between Trypanosoma cruzi and the extracellular matrix play an important role in cellular invasion. Here we show that T. cruzi increases the levels of thrombospondin‐1 (TSP‐1) expression in host cells during early infection. Stable RNA interference of host cell TSP‐1 knocks down the levels of TSP‐1 transcripts and protein expression in mammalian cells causing inhibition of T. cruzi infection. Addition of TSP‐1 to these cells restores infection. Thus, host TSP‐1, regulated by the parasite, plays a crucial role in early infection. This is the first report showing that a human parasite modulates TSP‐1 expression to facilitate infection.