LPS from P. gingivalis affects trophoblast-neutrophil interaction through TLR4 and favors a proinflammatory milieu.

G CALO; D PAPARINI; V HAUK; D VOTA; R RAMHORST; B LARA; F MERECH; C PÉREZ LEIRÓS; G CALO; D PAPARINI; V HAUK; D VOTA; R RAMHORST; B LARA; F MERECH; C PÉREZ LEIRÓS

Congreso; Reunion Anual de Sociedades de Biociencias; 2020

During placentation, trophoblast cells interact and secrete cytokine in order to regulate and maintain immune homeostasis. Changes or defects in this interaction may lead to pregnancy complications. In fact, neutrophil activation is associated with poor placentation and severe pregnancy complications. Porphyromonas gingivalis (Pg) is an important pathogen of periodontal disease that has been implicated in adverse pregnancy outcome but the mechanisms involved are still unclear. Pg-LPS is the most important virulence factor of Pg and activates both TLR4 and TLR2. The aim of this work was to evaluate the effect of conditioned media of trophoblast cells primed with Pg-LPS on neutrophil function. Human trophoblastic cell line Swan-71 was treated with Pg-LPS (10ng/ml) or Pg-LPS ultrapure, a variant that only activates TLR4. Cytokine expression was evaluated by RTqPCR, flow cytometry and ELISA. Peripheral blood neutrophils (Neu) and mononuclear cells (PBMCs) were purified from healthy donors and cultured with conditioned media from trophoblast cells (TbCM) treated or not with LPS (PgLPS-CM) or LPS ultrapure (PgLPSultraCM). Apoptosis was evaluated by microscopy and reactive oxygen species (ROS) by flow cytometry. Regulatory T cell induction was evaluated by flow cytometry.Pg-LPS ultrapure treatment increased trophoblast expression of TNFa, IL6 and IL1b compared to basal while Pg-LPS had no effect. In line with this result, Pg-LPS-CM had no effect on neutrophil activation whereas PgLPSultra-CM increased neutrophil activation with a higher release of ROS and decreased apoptosis rate (p≤0.05). Neutrophils exposed to TbCM induced FOXP3 expression on CD4+ T cell after 48h of coculture with PBMCs. This induction was diminished when neutrophils were preconditioned with PgLPS-CM or PgLPSultra-CM (P