INTERLEUKIN-2 ACTIVATION OF CYTOTOXIC-CELLS IN POSTMASTECTOMY SEROMA

Lymphocytes were isolated from breast seroma fluids and used to study the mechanism of activation of cytotoxic lymphocytes and possible role of immunological potentiation following surgery in breast cancer pati ents. Single or serial samples were obtained from patients who had und ergone mastectomy or lumpectomy with axillary node dissection. Lymphoc ytes were activated with rIL-2 (interleukin-2) and their cytotoxic act ivity was studied against Daudi and K562 cells and against a breast tu mor line (SKBr-3). All of the patients (21/21) responded to IL-2 stimu lation by significant activation of cytotoxic activity. The unstimulat ed cytotoxic activity of these cells against NK targets was low with l ess than 10% specific release in cytotoxicity assays. In simultaneous experiments, autologous seroma fluid was included during activation of lymphocytes to study possible regulatory molecules that may be presen t. In 17/21 patients, the presence of their seroma fluid, during the a ctivation period, enhanced or did not effect the cytotoxic potential o f their lymphocytes; inhibition was observed when seroma fluids from 4 /21 patients were included. Analysis of the cytotoxic population deriv ed from combined IL-2 and seroma treatments indicates the presence of cells with increased expression of CD56, and CD2, as well as in some c ases CD16 expression. Cytotoxic lymphocytes derived from IL-2 and sero ma treatments appeared to be more effective killers. Modulation of CD2 expression with seroma alone appeared to result in the generation of this highly cytotoxic population. This study demonstrates the role of CD2 expression in the effectiveness of LAK cell killing and also poten tial benefit of an immunotherapeutic approach to the postoperative tre atment of carcinoma of the breast. (C) 1996 Academic Press, Inc.