INFECTION BY T. CRUZI UP-REGULATES THE CATABOLIC PATHWAY OF TRYPTOPHAN IN HUMAN PLACENTAL VILLI

M.J. MOREIRA-ESPINOZA; E. BENIZIO; M.B. RABAGLINO; M. VARA MESLER; G.M. MAZZUDULI

Congreso; SLIMP/ SCHCF 2017 Latin American Society for Maternal Fetal Interaction and Placenta; 2017

Tryptophan catabolic pathway participates in immunologic tolerance of the foeto-maternal relationship. Indoleamine 2,3-dioxygenase (IDO) which contributes to immune regulation by catalyzing the essential amino acid tryptophan along the kynurenine (Kyn) pathway, is highly expressed in the placenta. In turn, Kyn is a natural ligand for Aryl hydrocarbon receptor (AhR). This system has been described to participate in the infection of Chagas disease, but the interaction of placental tissue with Trypanosoma cruzi (T. cruzi), the causal agent of congenital Chagas transmission, is not yet studied.Objective: To evaluate the effect of T. cruzi infection on the catabolism of tryptophan in a human placenta villous model.Methods: Chorionic villi explants were co-cultured with (infected, n = 3) or without 105 trypomastigotes (Tulahuen strain; control, n = 3) for 24 h. PCR for T. cruzi DNA was employed to analyse infected explants. Spectrophotometric assays were used to measure IDO enzymatic activity and Kyn production. Western blot (ß-actin was internal reference) and immunohistochemistry were used to explore protein.Results: PCR positive to T. cruzi DNA were observed in infected explants. Infected chorionic villi explants show higher IDO specific activity (6.05 ± 0.38 vs. 2.46 ± 0.26 nmoles/min/mg protein P