Flow cytometry analysis of immune cell populations isolated from cervicovaginal secretions of cynomolgus monkeys.

Flow cytometric analysis was used in this study to characterize the lymphocyte population present in the vaginal mucosa of the cynomolgus monkey. Vaginal immune cells were obtained, using absorbent wicks, from 11 normal cycling female monkeys at different stages of the menstrual cycle and from three nursing monkeys (not cycling). Leucocytes, including lymphocytes and monocyte-macrophage cells, were present in the cervicovaginal secretions of healthy cynomolgous primates throughout the three phases of the menstrual cycle. We also found that even if immune cells were constant throughout the menstrual cycle, among the T cell subsets there were differences. CD8+ cells [14.5+/-9% (mean+/-S.D.); range 3-30%] were more numerous compared to the mean number of CD4+ cells [7.3+/-5% (mean+/-S.D.); range 2-15%]. Characterization of the vaginal cells during the nursing period showed that the monocyte-macrophage (CD14+, CD11c+) cells were abundant compared with the low number of both B (CD20+) and T cells (CD2+). Our results show that cytometric analysis by FACS can be used to identify the immune cell populations present at the local level. This technique may provide a useful tool by which the vaginal environment can be studied in order to correlate cell phenotype with immune function.