Distribution of leukocyte subpopulations in the human corpus luteum

Cytokines, as secreted products of leukocytes, have roles in many organs of the body via paracrine or autocrine mechanisms. In the present study, we demonstrate by immunocytochemistry the leukocytes present in the human corpus luteum in order to investigate further the relationship between leukocytes, cytokines and corpus luteum function. Ten intact corpora lutea were collected from female patients who had no apparent ovarian disease. The mean age of these patients was 37 years (range 23-55 years). Frozen and paraffin sections were subjected to analysis using monoclonal antibodies which were specific to leukocyte marker antigens. The results showed that there are macrophages, cells positive for leukocyte common antigen (LCA), T lymphocytes including T helper/inducer (T4) cells, T cytotoxic/suppressor (T8) cells and activated T (Ta) cells (interleukin-2 receptor-positive cells), monocytes and natural killer (NK) cells but not B lymphocytes present in the human corpus luteum. The distribution of the leukocytes present in the different parts of the corpus luteum was found to be in the order: theca-luteal area greater than loose connective tissue area greater than granulosa-luteal area. Macrophages and T lymphocyte subsets comprised the main components of the total leukocytes in the human corpus luteum. Ta cells were only localized in the loose connective tissue of the corpus luteum. In most cases, macrophages, LCA cells and T4 cells tended to be situated in a single cell layer on the edge of the theca-luteal area and surrounding the granulosa-luteal area. These results suggest that the leukocytes may act to a greater extent in the theca-luteal area than in the granulosa-luteal area.(ABSTRACT TRUNCATED AT 250 WORDS)