Three different types of cytotoxic activities have been studied in a syngeneic system of mammary tumors transplanted in Balb/c mice. Increased reactivities paralleling tumor growth were obtained in phytohemagglutinin-induced cytotoxicity, antibody-(Ab) dependent cellular cytotoxicity (ADCC) and the recently described specifically-induced, nonspecifically-expressed cytotoxicity (SINEC). In the last mentioned assay lymphocytes sensitive to a tumor antigen (Ag) become activated upon confrontation with the Ag and become lytic against unrelated target cells. The increase in these 3 parameters of cell-mediated immunity with tumor growth is in sharp contrast with previous results obtained in the same model system with the migration inhibition and lymphocyte transformation assays, where positive reactions disappeared with advancement of tumor. These findings indicate that tumor growth has diverse effects on the immune system of the host. The contrasting extremes intimate that different cell populations are involved directly or indirectly in the tumor-host interactions and the expression of immunologic responses.
|Original language||English (US)|
|Number of pages||7|
|Journal||RES Journal of the Reticuloendothelial Society|
|State||Published - Dec 1 1977|
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