Higher levels of activation markers and chemokine receptors on T lymphocytes in the cervix than peripheral blood of normal healthy women.

Heterosexual transmission of human immunodeficiency virus (HIV-1) is the predominant mode of infection world-wide. To better understand sexual transmission of HIV-1 in women we have analysed virus co-receptor and cellular activation marker expression on T lymphocyte subsets from the cervical epithelium and have made comparisons with peripheral blood T cells. Intraepithelial cervical T lymphocytes were obtained with a cytobrush, immunolabelled and analysed by flow cytometry. Activation markers (CD69, CD25 and HLA-DR) were found to be more highly expressed on cervical than on blood T lymphocytes. These higher levels of activation on cervical T lymphocyte subsets could facilitate HIV-1 infection. CXCR4 was expressed at marginally higher levels than CCR5 on T cells from the cervical epithelium and peripheral blood. Thus, the preferential transmission of macrophage tropic strains of HIV-1 following sexual contact cannot be explained solely on the expression of chemokine co-receptors by T lymphocyte subsets.