Phenotype of villous stromal cells in placentas with cytomegalovirus, syphilis, and nonspecific villitis.

Villous stromal cells (VSC) play an important role in fetomaternal placental immune function. We studied the phenotype of VSC in infection by cytomegalovirus (CMV) and syphilis as well as nonspecific villitis and compared the findings with gestational age-matched controls. Monoclonal antibodies directed against total leukocytes, T cells, B cells, macrophages, dendritic cells, granulocytes and HLA-DR as well as polyclonal antibodies against S-100, alpha-1 antichymotrypsin, and lysozyme were used. In controls, the immunocytochemical response for each marker was either negative or weakly positive. In contrast, the VSC in CMV-infected and nonspecific villitis showed intense reactivity to various macrophage markers. In syphilis, reactivity with macrophage markers such as lysozyme and MAC387 were weaker, and reactivity to HLA-DR and S-100 was much stronger. Endothelial cells strongly expressed the monocyte/granulocyte marker CD15 in the diseased states, especially in syphilis, relative to controls. We conclude that the phenotype of VSC is altered in disease states and that the changes are dependent to some degree on the specific subset of chronic villitis.