Relevance of VIP in the maintenance of the immune ovarian homeostasis

LARA CASTAGNOLA; LUCILA GALLINO; DAIANA VOTA; ESTEBAN GRASSO; MARÍA SOLEDAD GORI; FERNANDA PARBORELL; CLAUDIA PÉREZ LEIRÓS; VANESA HAUK; ROSANNA RAMHORST

Congreso; Reunión Anual de La Sociedad Argentina de Inmunología; 2023

Ovarian aging is associated with inflammation, contributing to the decline in oocyte count and quality. Since the vasoactive intestinal peptide (VIP) is an immunopeptide found in the reproductive tract with anti inflammatory effects inducing a tolerogenic response, we aim to understand VIP contribution to control ovarian immune homeostasis in order to prevent premature aging.Wild type (WT) mice 3 (young) or 8 (aged) months old and young VIP Knockout (KO) in estrus were used. The ovaries were examined after histological staining, reactive oxygen species (ROS) levels were measured by flow cytometry using DCFH-DA probe and IL-1β secretion was determined by ELISA. Long-term phagocytosis assays (24, 48, 72h) of apoptotic thymocytes were performed to obtain foamy macrophages. Peritoneal WT or VIP KO macrophages were preconditioned with ovarian media from WT or VIP KO mice for 48h, followed by short-term phagocytosis assays (120 min) using apoptotic bodies stained with PKH26 to assess their phagocytic capacity. Phagocytic capacity was measured as the percentage of PKH26+ cells in the macrophage gate. In both assays, after phagocytosis, lipid droplets were determined by flow cytometry using BODIPY 493/503.We confirmed that during reproductive aging WT females show a smaller number of ovarian follicles, accompanied with altered ovarian histology, in comparison with young WT mice. These parameters were found to be exacerbated in young VIP KO mice, with significantly more atretic follicles and less mature follicles (p