Differential expression of class II major histocompatibility complex and Thy 1.2 antigens on mouse decidua

A differential expression of class II major histocompatibility complex (MHC) and Thy 1.2 antigens was detected on two morphologically distinct cell populations in short-term cultures of murine decidual tissue. Stromal type decidual cells expressed Thy 1.2, albeit transiently, and consistently lacked class II antigens. By contrast decidual macrophages expressed class II antigens and lacked Thy 1.2 antigens. Stromal type decidual cells, after culture in the presence of indomethacin, displayed no evidence of prostaglandin-mediated modulation of class II expression. These findings suggest that class II positive decidual macrophages are responsible for the antigen-presenting capacity of decidua.