Expression of class II HLA molecules by endothelial cells of human decidua

Antigen phenotype of cultured decidual stromal cells of human term decidua

We previously reported that decidual stromal cells (DSC) from early human decidua express antigens associated with hematopoietic cells and develop different immune functions. Here we study the antigenic phenotype of DSC from term decidua and compare it with the phenotype reported for DSC from early decidua. Decidual stromal cells were isolated from human term deciduas and maintained in culture until highly purified DSC cultures were obtained. Most term DSC, like most early DSC, expressed CD10. Term DSC expressed antigens specific for follicular dendritic cells (FDC), such as DRC-1 (CD21L) and HJ2, together with CD21, CD23 and CD80, which are detected on FDC as well. Also like early DSC, term DSC were negative for CD3, CD14, CD15 and CD45. Although early DSC were reported to be HLA-DR-positive and CD86-positive, these antigens were not expressed by term DSC. These discrepant results suggest that two types of cells, or cells at different stages of differentiation (decidualization) were selected during culture of decidual cells from different periods of gestation. This possibility was further supported by the finding that term DSC expressed desmin and prolactin, two markers of decidualization, whereas these molecules have not previously been detected in early DSC.

Cultured human decidual stromal cells express antigens associated with hematopoietic cells

Although decidual stromal cells (DSC) have classically been considered to play a nutritional role during pregnancy, several reports have demonstrated that they can also exert different immune activities. Furthermore, some authors have occasionally found antigens on DSC normally expressed by immune cells. In this study, we isolated and cultured 12 human DSC lines and studied them with immunocytochemistry and flow cytometry using monoclonal antibodies against antigens associated with hematopoietic cells. Decidual stromal cells exhibited a constant phenotype: they were CALLA (CD10)-positive and DR-positive, although the expression of CD45, the leukocyte common antigen, was found to be very weak or negative. We also detected myelomonocytic antigens CD11b (CR3), CD13, CD16 (Fc gamma RIII) and CD36, although DSC lacked CD14, CD15 and CD33. B cell antigens CD20, CD21 (CR3), CD23 (Fc epsilon RII) and CD24 were expressed. DRC-1, an antigen detected on follicular dendritic cells (FDC), was also observed on DSC. When these cells were cultured in the presence of progesterone, they expressed desmin and prolactin (PRL), findings that confirmed their identity as DSC. The phenotype described, together with the immune activities reportedly carried out by DSC, suggest that DSC may play a role in the maternal-fetal immune relationship.