Assessment of immunological parameters during tumour development in a murine model.

Natural Killer activity assessed by 51Cr release assay from K-562 cells showed detectable activity from 5th day after tumour transplantation, reaching a peak on 12th day and thereafter showing a gradual decline in the activity. Antibody dependent cell mediated cytotoxicity estimated by 51Cr labelled sheep red blood cells anti SRBC system demonstrated a peak activity on 5th day. Cytotoxic T lymphocyte activity detected by 51Cr release of Dalton's lymphoma ascites target cells showed a peak on 10th day. Antibody complement mediated cytotoxicity revealed a similar pattern as natural killer cell activity.