Ontogeny of the MHC antigens on human trophoblast cells during the first trimester of pregnancy.
The presence and the ontogeny of class I and class II major histocompatibility (MHC) antigens were investigated on human trophoblast cells in single cell suspensions of collagenase dispersed placentae during the first trimester of pregnancy by using a highly sensitive radioautographic approach. Cells were treated with monoclonal anti-HLA-A,B,C or anti-HLA-DR (or anti-human Ia) antibodies followed by 125I-labeled protein A, normal mouse serum, or medium alone used as negative controls, and monoclonal antibodies against trophoblast specific antigenic markers (anti-Trop 2, NDOG-1, and NDOG-2) used as positive controls for specificity of trophoblast labeling. Tissue controls were provided by Ficoll-paque-separated adult human peripheral blood lymphocytes (PBL), and placental lymphocytes were used as additional internal controls. Results revealed variable but specific labeling of cytotrophoblast cells for class I but not class II MHC antigens at all gestational stages during the first trimester. The incidence of HLA-A,B,C antigen-bearing cytotrophoblast cells in early gestational (5 to 8 wk) placentae was high (75 to 91%) in the minority, but was low to medium (35 to 66%) in placentae at later gestational intervals (9 to 12 wk). The initial antigen density on the labeled cytotrophoblast cells as reflected by the median silver grain counts per unit area was approximately 75% of that noted on adult PBL or placental lymphocytes at 5 to 7 wk. The density then dropped to 50% of the initial level by the eighth week of gestation with no further change up to 12 wk. Syncytiotrophoblast cells revealed no appreciable labeling for either antigen class. This could not be explained by antigen stripping due to the collagenase dispersion procedure; specific labeling was not detectable on the syncytiotrophoblast cell layer in situ in histologic sections after intact chorionic villi had been directly exposed to 125I-labeled monoclonal anti-class I antibody. These results are qualitatively similar to our findings in the mouse in revealing the presence of class I MHC antigens on a major population of trophoblast cells.
D000818:Animals; D005260:Female; D005802:Genes, MHC Class II; D006680:HLA Antigens / Q000032:analysis* / Q000145:classification / Q000235:genetics; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D013205:Staphylococcal Protein A / Q000378:metabolism; D014327:Trophoblasts / Q000276:immunology*
D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D013205:Staphylococcal Protein A