NATURAL KILLER ACTIVITY IN HUMAN OVARIAN TUMORS

Publisher Summary This chapter examines the natural killer (NK) activity in human ovarian tumors. The defective NK activity of tumor-associated lymphoid cells (TAL) could, in principle, be accounted for by at least two mechanisms, one being the presence of suppressor cells or factors and the other being a low number of the relevant effectors, identified in blood as large granular lymphocytes (LGL), which enter the tumor. In a study described in the chapter, preliminary evidence for the presence in situ of cells inhibiting NK activity was obtained in 3 peritoneal effusions from ovarian cancer in 2 breast carcinomas and in pleural carcinomatous effusions. A relatively large number of ovarian cancer patients are examined for the presence of suppressor TAL or TAM. In part of the experiments, TAL or tumor-associated macrophages (TAM) were mixed in varying ratios with PBL and lysis of K562 cells was measured immediately, whereas in others, suppressors were allowed to interact with PBL for 20 h before adding indicator PBL.TAM were devoid of suppressive activity on NK cells when the assay was performed immediately after mixing, whereas in a minority of TAL preparations, the preliminary indications for the presence of inhibitory cells at the tumor site were confirmed.