Ex vivo infection of human placental chorionic villi explants with Trypanosoma cruzi and Toxoplasma gondii induces different Toll-like receptor expression and cytokine/chemokine profiles

Abstract

Problem: Trypanosoma cruzi and Toxoplasma gondii present, respectively, low and high congenital transmission rates. The placenta as an immune regulatory organ expresses TLRs, leading to the secretion of cytokines. Both parasites are recognized by TLR-2, TLR-4, and TLR-9. Here, we studied if the parasites induce differences in TLR protein expression, cytokine profiles, and whether receptor inhibition is related to parasite infection.

Method of study: Placental tissue explants were infected ex vivo with each parasite, TLRs protein expression, cytokine profile and parasite infection were determined by Western blotting, ELISA and qPCR.

Results: Trypanosoma cruzi and Toxoplasma gondii infection is related to TLR-2 and TLR-4/TLR-9, respectively. Trypanosoma cruzi elicits an increase in TNF-α, IL-1β, IL-6, IL-8 and IL-10 cytokine secretion whereas T. gondii only increases the secretion of IL-8.

Conclusion: The susceptibility of the placenta to each parasite is mediated partially by the innate immune response.

Keywords: Toxoplasma gondii; Trypanosoma cruzi; Cytokines; Toll-like receptors; placental infection.