BLASTOCYST QUALITY MODULATES THE GENERATION OF AN INFLAMMATORY MICROENVIRONMENT BY DECIDUALIZED CELLS

L. FERNÁNDEZ; E. GRASSO; E. SOCZEWSKI; S. GORI; G. CALO; V. HAUK; G. MARTINEZ; M. IRIGOYEN; C. PÉREZ LEIRÓS; R. RAMHORST

Congreso; ESHRE virtual 36th Annual Meeting; 2020

Problem: Decidualized cells display an active role during embryo implantation sensing blastocyst quality, allowing the implantation of normal developed (ND) blastocysts and preventing the invasion of impaired developed (ID) ones. Here, we characterized the immune microenvironment generated by decidualized cells in response to soluble factors secreted by ND and ID blastocysts that shape the receptive milieu.Method of Study: We used an in vitro model of decidualization based on the Human EndometrialStromal Cells line (HESC) differentiated with medroxiprogesterone and dibutyryl-cAMP, then treatedwith human blastocyst-conditioned media (BCM) from ND or ID blastocysts.Results: Decidualized cells treated with ID-BCM increased IL-1 while decreased IL-10 production. Nextwe evaluated the ability of decidualized cells to modulate other mediators associated withmenstruation as chemokines. Decidualized cells respond to ID-BCM stimulation increasing CCL2 andCXCL12 expression and CXCL8 secretion. The modulation of these markers was associated with therecruitment and activation of neutrophils, while regulatory T cells recruitment was restrained. Thesechanges were not observed in the presence of ND-BCM.Conclusion: Soluble factors released by ID-blastocysts induce an exacerbated inflammatory responseassociated with neutrophils recruitment and activation, providing new clues to understand themolecular basis of the embryo-endometrial dialogue.