부산대학교 도서관

In vitro macrophages treated with novel peptides have been shown to develop enhanced tumoricidal activity against tumor target cell (P815), though the exact mechanism is not known. In the present study, we have investigated the mechanism involved in the tumor cell cytotoxicity mediated by novel peptides treated macrophage and involvement of possible effectors molecule. Peritoneal exudated macrophages treated with LPS, peptides, and LPS plus peptides and when cocultured with tumor cell P815 caused tumor cell death by induction of apoptosis. The results of our experiment reveal a specific pattern of intranucleosomal DNA fragmentation detected by agarose gel electrophoresis and also with microscopic examination of the cells revealed nuclear alteration characteristic of apoptosis. Viability studies showed that most of the cells undergoing apoptosis were found to be non-viable even after 24 h coculture. Macrophage induced apoptosis in tumor target cells even in the absence of cell to cell contact through diffusible effectors molecule. The study thus shows that the novel peptide treated macrophage can kill tumor cell P815 by extracellular release of effectors molecule NO (nitric oxide) that act by inducing apoptosis in a target cell-specific manner.