@entity35 XXXX ) cell-mediated lysis is determined by the presence of @entity11265 on A-NK cells and the absence of major histocompatibility complex class I on target cells.

@entity5 @entity11265 @entity71208 @entity35
The precise mechanism by which target cells are recognized and subsequently lysed by @entity71208 ) cells is poorly understood. In this study the role of major histocompatibility complex (MHC) class I and adhesion molecules in the recognition and lysis of @entity5 cells was investigated in a syngeneic Wag @entity35 model. Preincubation of @entity5 cells with F(ab')2 fragments of anti-MHC class I monoclonal antibody (mAb) OX18 strongly enhanced the A-NK cell-mediated lysis. Also normal syngeneic cells such as T cells and A-NK cells became highly sensitive for lysis by A-NK cells after preincubation with mAb OX18. Two other mAb against MHC class I had no effect on lysis of target cells. These data indicate that masking of MHC class I on syngeneic @entity5 and normal cells by mAb OX18 is sufficient for A-NK cells to recognize target cells as non-self, resulting in lysis. In addition, we found that the presence of mAb against the beta 2 ( @entity11265 )-integrins blocked the lysis of all @entity5 cell lines by A-NK cells in 51Cr-release assays, also when target cells were preincubated with mAb OX18. Because of the absence of @entity11265 on most @entity5 cells we concluded that a @entity11265 -associated integrin on A-NK cells is essential for lysis of target cells. These results show that in this syngeneic @entity35 model @entity11265 on A-NK cells together with MHC class I on @entity5 cells determine A-NK cell-mediated lysis. Furthermore, we hypothesize that the anti-MHC class I OX18 recognizes an epitope on @entity35 MHC class I which is, or is very close to, the restriction element determining A-NK cell-mediated lysis.
