Luteal leukocytes are modulators of the steroidogenic process of human mid-luteal cells

Abstract

Flow cytometry analysis of luteal cells revealed that an important proportion of these cells are leukocytes. The percentage of leukocytes was higher in the early (42 ± 4) and late (35 ± 3) luteal phases than in the mid-luteal (24 ± 2) phase. However, the proportion of macrophages did not differ between the luteal stages. The flow cytometric properties correlated with cellular size and granularity were not reliable as discriminators of luteal cell subpopulations. Therefore, to assess the contribution of luteal leukocytes, these cells were completely removed from luteal cell suspensions (total cells), by a negative selection procedure (immunomagnetic separation). The functional role of leukocytes in mid-luteal steroidogenesis was assessed, in total as well as leukocyte-depleted cells. Progesterone production was found to have increased 2.2-fold in leukocyte-depleted cell cultures, in comparison with total cells under basal conditions. However, the response to human chorionic gonadotrophi