Human amnion cells: modulation of expression of specific antigens

Antigen expression by fetal cells near the mother is of interest because of the possibility that some antigens may stimulate beneficial maternal immune responses or may prevent the development of harmful responses. The recent generation of monoclonal antibodies to amnion and trophoblast antigens together with the finding that class I histocompatibility antigen (HLA) expression by amnion cells can be manipulated provided an opportunity to determine if any relationships exist among expression of HLA, amnion antigens, and trophoblast antigens. The results of the present study demonstrate that: class I HLA and amnion-specific antigens are co-expressed by IFN-gamma-modulated amnion cells, so neither prevents expression of the other; EGF enhances expression of two amnion-specific antigens; amnion cells do not express transferrin receptors, placental alkaline phosphatase, or other antigens normally associated with trophoblasts following exposure to IFN-gamma and/or EGF. The results demonstrate independent modulation of expression of class I HLA, two amnion-specific antigens, and some trophoblast-associated antigens on amnion epithelial cells.