METALLOPROTEINASE SECRETION BY ENDOMETRIAL LEUKOCYTE SUBSETS

PROBLEM: Human endometrium contains up to 40% leukocytes. Since their function is unclear, we cultured these cells separately to analyze the ir proteolytic potential in vitro. METHOD: Endometrium was obtained fr om hysterectomies or from first trimester abortion. After collagenase digestion, the different leukocyte subsets (CD56, CD3, CD19, CD16, CD4 5) were immune-separated and cultured. Gelatine zymography and a quant itative type IV gelatinase assay were run on all culture supernatants. RESULTS: On zymography, all subtypes of endometrial leukocytes releas ed gelatinases. The 72-kDa gelatinase was absent from peripheral leuko cyte supernatants, whereas it was secreted by all endometrial leukocyt es. The 92-kDa gelatinase was present in all culture supernatants. Lar ge granular lymphocytes (CD56+, LGL) expressed the highest type VI gel atinase activity as compared to all other leukocytes. This activity in creased during the cycle in LGL and T cells but remained unchanged in glandular and stromal cells. CONCLUSIONS: Endometrial leukocytes, part icularly LGL, secrete significant amounts of gelatinases.