抄録
The phenotype of mammary intra−epithelial lymphocytes (mIEL) has not been described. In order to determine the potential role of mIEL to the mammary epithelial cells of cows, it is important to characterize these cells during the lactating periods. The phenotype of mIEL was analyzed using monoclonal antibodies to lymphocyte surface markers. In the alveolar epithelium of mammary glands, a higher percent of CD8+ mIEL was constituted of TCR1+ cells expressing γ/δ T cell receptor (γ/δ T cells) and ACT2+ cells expressing both activation markers of null cell and CD8+ T cell. Both γ/δ T cells and ACT2+ cells were preferentially distributed in the mammary epithelium. ACT2+ cells were about twice as many as γ/δ T cells. The ratio of CD4+/ CD8+ T cells was less than 0.3 in the alveolar epithelium. A quantitative cytological analysis by flow cytometry showed that lymphocytes isolated from mammary gland secretions (MGSLy) co−expressed CD8 and γ/δ T cell receptor, CD8 and ACT2 or ACT2 and γ/δ T cell receptor. The results suggest that CD8+ mIEL in cows coexpress γ/δ T cell receptor and/or ACT2.
