Deep Infiltrating Endometriosis and Activation and Memory Surface Markers and Cytokine Expression in Isolated Treg Cells

It is not yet clear whether regulatory T (Treg) cells are active, and whether they play a favorable or adverse effect on endometrial foci implantation. Our aim was to evaluate activation and memory surface markers in Treg isolated from peritoneal fluid (PF) and peripheral blood (PB) of women with deep endometriosis and to assess its cytokine mRNA expression. This case-control study included 49 women with deep infiltrating endometriosis and 20 healthy controls. It was analyzed PF and PB of both groups. Cell surface markers GITR, TNFRII, HLA-DR, ICOS, CTLA-4, CD45RA, and CD45RO were evaluated in Treg (CD3⁺CD4⁺CD25⁺CD127^lowFoxp3⁺) cells by flow cytometry. Additionally, Foxp3, TGF-beta, IL-10, IL-6, and TNF-alpha mRNA expression was assessed by real-time PCR in Treg cells (CD4⁺CD25⁺CD127^dim/-) isolated using magnetic microbeads. Women with endometriosis had higher percentages of TNFRII+ Treg and CTLA-4+ Treg in their PB, and lower percentages of ICOS+ Treg and CD45RO+ Treg in their PF. The groups displayed no differences in mRNA expression. Regardless of the group, in PF, the percentage of Treg cells overall and of CD45RA+ Treg cells were significantly lower, whereas the percentage of TNFRII+ Treg and CD45RO+ Treg were significantly higher than in PB. Foxp3 and TGF-beta mRNA expression were also higher in PF than in PB. Our results indicated that Treg cells in women with endometriosis have a distinct profile of activation and memory markers, but similar cytokine expression. Moreover, we could observe clearly that Treg cells have distinct profile regarding their origin site.