Monoclonal antibodies to T cell receptor gamma/delta complex react with human endometrial glandular epithelium

We have tested a panel of four monoclonal antibodies to the T cell receptor (TCR) gamma/delta heterodimer (delta TCS-1, TS-8, TCR delta-1, anti- C gamma m 1) in pregnant and non-pregnant uteri. The TCR gamma/delta complex was not detected on stromal lymphocytes, but was localized in the cytoplasm of the endometrial glandular epithelium from most pregnant uteri. These antibodies also reacted with endometrial glandular epithelium in a majority of non-pregnant uteri; the reactivity was more consistent in secretory phase glands than that in the proliferative phase of menstrual cycle. However, three different monoclonal antibodies to CD3 (OKT3, leu 4, UCHT-1) failed to show any reactivity, suggesting that the presence of the TCR gamma/delta complex was not associated with CD3 complex. The TCR gamma/delta-positive glandular epithelial cells did not react with two monoclonal antibodies to the TCR alpha/beta complex, and they were also CD4- and CD8-negative. Together with the loss of the class 1 MHC antigens from these endometrial glandular epithelial cells in early pregnancy, these data suggest that these TCR gamma/delta-bearing endometrial glandular cells may undergo phenotypic alterations under local regulation of gene expression.