Human trophoblasts cells modulate the occurrence of apoptosis in monocytes infected by Toxoplasma gondii

s / Placenta 36 (2015) 469e521 520 Methods: For this purpose, HTR-8/SVneo cells were treated or not with the supernatant from uninfected or infectedmacrophages and then infected or not by T. gondii. Cytokine secretion and soluble FasL were analyzed by ELISA, apoptosis index and Fas/CD95 expression were determined by flow cytometry and intracellular parasite proliferation was analyzed by enzymatic assay. Results: IL-6 secretion by HTR-8/SVneo cells was synergistically increased with both stimuli, supernatant from macrophages and T. gondii infection. The apoptosis index of infected HTR-8/SVneo cells was decreased in the presence or absence of supernatant from infected macrophages. On the other hand, the apoptosis of infected HTR-8/SVneo cells increased when these cells were treated with supernatant from uninfected macrophages. Also, a low expression of Fas/CD95 and a high soluble FasL release were observed in these conditions. Finally, we did not verify any change in the proliferation of T. gondii. However, there is down-modulation of apoptosis in HTR-8/SVneo cells by the parasite, which probably relates to favoring its establishment in the host cell, while the functional activities of macrophages toward restoring these cell death rates, keep gestational events of invasion and placentation appropriate. Conclusions: All together, these results contribute to better understanding the mechanisms of cellular communication between the extravillous trophoblast cells and macrophages, and demonstrate that infection with T. gondii can interfere with this interaction through the modulation of cell death by apoptosis. PB.47. HUMAN TROPHOBLASTS CELLS MODULATE THE OCCURRENCE OF APOPTOSIS IN MONOCYTES INFECTED BY TOXOPLASMA GONDII A.S. Castro , F.C. Oliveira , P.S.G. Gois , C.M.O.S. Alves , M.B. Angeloni , P.M. Guirelli , R.J. Silva , P.S. Franco , A.O. Gomes , B.F. Barbosa , T.W.P. Mineo , E.A.V. Ferro . 1 Institute of Biomedical Science, Histology and Embryology Department, Federal University Uberlandia, Uberlandia, Brazil; 2 Institute of Biomedical Science, Pharmacology Department, Federal University Uberlandia, Uberlandia, Brazil; 3 Institute of Biomedical Science, Immunoparasitology Department, Federal University Uberlandia, Uberlandia, Brazil Human trophoblast cells modulate the occurrence of apoptosis in monocytes infected by Toxoplasma gondii Objectives: a) to evaluate the role of trophoblast cells (BeWo) in monocyte (THP-1) activity, specifically apoptosis, in the presence or absence of T. gondii infection; b) to investigate whether BeWo cells alter the expression of death receptor (CD95) in THP-1 cells; c) to investigate FasL release by BeWo and THP-1 cells as well as in THP-1 cells stimulated with supernatant from BeWo cells. Methods: THP-1 cells were stimulated with supernatants of BeWo cells previously infected or not with T. gondii, and then infected with parasites. Supernatant of both cells was collected and analyzed for FasL secretion by ELISA. Furthermore, the occurrence of apoptosis in THP-1 cells and the expression of death receptor (CD95) in these cells were evaluated by flow cytometry. Results: The apoptosis index in THP-1 cells stimulated with supernatants of BeWo cells was higher than in untreated THP-1 cells. In the group of infected THP-1 cells, the apoptosis index decreased at all conditions when compared to the group of uninfected THP-1 cells. However, the expression of death receptor (CD95) was higher in the group of infected THP-1 cells and the stimulus with supernatants of BeWo cells induced a higher expression of this receptor in THP-1 cells. Finally, the secretion of FasL was higher in the group of infected THP-1 cells and supernatant of BeWo cells induced the reduction of FasL secretionwhen compared to controls in both groups. Conclusions: Trophoblast cells and T. gondii alter the occurrence of apoptosis, expression of death receptor (CD95) and secretion of FasL in monocytes. These data can be associated with an immune response established by trophoblast cells and monocytes to protect the fetus against infection, although these findings can also represent a potential survival mechanism of the parasite. PB.48. CHLORPYRIFOS EXPOSURE INDUCES TROPHOBLAST BARRIER AND STROMA ALTERATIONS IN HUMAN CHORIONIC VILLOUS EXPLANTS M.E. Ridano , A.C. Racca , J.B. Flores-Martin , E. Bevilacqua , S. GentiRaimondi , R.E. Fretes , G.M. Panzetta-Dutari . CIBICI-CONICET, Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional C ordoba, Argentina; 2 Institute of Biomedical Sciences, University of S~ ao Paulo, S~ ao Paulo, Brazil; Departmento de Histologia y Embriologia, Facultad de Medicina, Universidad Nacional