In vitro cytolytic activity of human NK cells against osteosarcoma cell lines.

NK lymphocytes present CD16, CD56 and lack CD3 surface molecules and are able to spontaneously lyse tumor or virus infected cells. In this study we evaluated the susceptibility of some human osteosarcoma cell lines to NK cytolytic activity and standardized the assay conditions. NK lymphocytes were used as effector cells in a cytotoxicity test against HOS, U-2 OS and Saos-2 osteosarcoma targets. While HOS cells were susceptible on the contrary U-2 OS and Saos-2 were osteosarcoma resistant lines. Our preliminary results support a model for the study of a possible interaction between the immune system and these tumors.