DIFFERENT EFFECTS OF BREAST-CANCER, HIV-1 INFECTION AND CHEMOTHERAPY ON INDUCIBLE NATURAL IMMUNITY

Breast cancer chemotherapy and HIV-1 viral infection (AIDS) can result in respective transient or irreversible losses of up to 40-50 % of ci rculating lymphocytes. The relationship of lymphopenia on tumor immuno surveillance and the control of opportunistic infections has yet to be established. The objective of this study was to characterize the chan ges in natural killer ( NK) and lymphokine activated killer (LAK) cell function associated with cytotoxic drug therapy, breast cancer and HI V-1 infection. NK and LAK activities were measured at multiple effecto r to target ratios. Exponential regression analysis of target cell lys is determined the maximal % target kill and the lytic potential of eff ector cells. Flow cytometric analysis of lymphocyte subsets in seropos itive populations was performed to determine the % of NK(CD56+) cells. Taken together, our findings indicate that cytotoxic NK pool sizes in creased in breast cancer patients, diminish consequent to chemotherapy . The functional capacity of individual NK and LAK cells remains intac t. In contrast, the diminution of NK and LAK functional responses in H IV-1 seropositive individuals is associated with reductions in cytotox ic NK and LAK pool sizes, as well as marked reductions in cytolytic fu nction of individual cells. Zidovudine (AZT) treatment did not affect LAK activity in HIV+ subgroups. Our findings indicate that NK and acti vated LAK functions are affected both by chemotherapy and disease etio logy.