Monoclonal antibodies to T cell receptor γ/δ complex react with human endometrial glandular epithelium

We have tested a panel of four monoclonal antibodies to the T cell receptor (TCR) γ/δ heterodimer ( δTCS-1, TS-8, TCR δ-1, anti-C γm 1) in pregnant and non-pregnant uteri. The TCR γ/δ 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 CD 3 (OKT 3, leu 4, UCHT-1) failed to show any reactivity, suggesting that the presence of the TCR γ/δ complex was not associated with CD 3 complex. The TCR γ/δ-positive glandular epithelial cells did not react with two monoclonal antibodies to the TCR α/β complex, and they were also CD 4- and CD8-negative. Together with the loss of the class IMHC antigens from these endometrial grandular epithelial cells in early pregnancy, these data suggest that these TCR γ/δ-bearing endometrial glandular cells may undergo phenotypic alterations under local regulation of gene expression.