Decidualization program conditions maternal monocytes to a DC-10 profile inducing regulatory T cell response.

SOCZEWSKI, E.; BLEJER, JORGELINA; PEREZ LEIRÓS, C.; SCHAFIR, A.; GRASSO, E.; SALAMONE, G.; RAMHORST, R.; FERNÁNDEZ, L.; GRASSI BASSINO, M.; GORI, S.

Congreso; SAI-SAIC-SAFIS 2020; 2020

The decidualization program allows the secretion of immunoregulatory factors by endometrial stromal cells which may condition maternal leukocytes to a regulatory profile. In this context, we previously showed that decidualized cells conditions maternal monocytes to a tolerogenic profile with characteristics of Myeloid Regulatory Cells (MRC), particularly DC-10. This novel and distinctive subset of dendritic cell is characterized to be a potent IL-10 producer and type 1 regulatory T (Tr1) cells-inducer through HLA-G pathway. Considering that DC-10 was found increased in decidua, here we focus on the impact of decidualization in conditioning monocytes to this subset and its ability to induce Foxp3neg regulatory T cells. Thus, conditioned media (CM) of human endometrial stromal cell line decidualized with MPA+dbcAMP for 8 days (Dec-CM) or not (Non-dec CM) were collected. Then, isolated monocytes from peripheral blood mononuclear cells of healthy women were cultured with rhGM-CS F+rhIL-4 for 5 days in the absence/presence of CM. Whereas both Non-dec and Dec-CM-cultures showed increased IL-10 secretion by monocyte-derived cells, only Dec was able toinduce a higher expression of the characteristic DC-10 tolerogenic markers HLA-G and ILT2/CD85j (p