Tumor-infiltrating lymphocytes from ovarian tumors of low malignant potential

Tumor-infiltrating lymphocytes (TIL) from human ovarian tumors of low malignant potential (LMP) were studied in situ by immunohistology and characterized functionally after isolation from tumors. In comparison to ovarian carcinomas, borderline (LMP) ovarian tumors contained significantly fewer infiltrating leukocytes. Phenotypically, TIL from LMP tumors contained significantly fewer activated (HLA-DR+ or CD25+) lymphocytes than did fresh TIL from ovarian carcinomas. Also, percentages of CD3-CD56+ natural killer cells were higher in LMP than in ovarian carcinomas. TIL obtained from LMP tumors proliferated well in vitro in the presence of interleukin 2 (IL2) and tumor necrosis factor alpha (TNF alpha) but did not show a selective enrichment in CD3+CD8+T lymphocytes generally observed with TIL from ovarian carcinomas. Antitumor cytotoxicity against a panel of tumor cell targets of cultured TIL from LMP tumor did not parallel that of effectors generated from autologous peripheral blood lymphocytes. However, no significant enrichment in reactivity against autologous tumor cells was observed in long-term cultures of TIL from LMP tumors. Thus, considerable differences were observed between phenotypic and functional characteristics of lymphoid cells infiltrating LMP tumors and invasive ovarian carcinomas.