Selective and unidirectional membrane redistribution of an H-2 antigen with an antibody-clustered viral antigen: Relationship to mechanisms of cytotoxic T-cell interactions

We have studied the co-redistributions of vesicular stomatitis virus (VSV) antigen and of individual H-2 antigens on the surfaces of mouse cells, and in parallel we have also used these VSV-infected cells as targets in cytotoxic T-cell killing experiments. Antibody-induced patching and capping of the VSV antigen caused an extensive co-patching and co-capping of the H-2K^b antigen but not of the H-2D^b antigen. In reciprocal experiments, the antibody-induced patching of the H-2K^b or H-2D^b antigen did not result in a co-patching of the VSV antigen. Radioimmunassays showed that the relative numbers of H-2K^b, H-2D^b, and VSV antigens on the surfaces of the cells exhibiting such nonreciprocal co-redistributions were closely similar. Furthermore, the H-2 restricted cytotoxic T-cell lysis of these target cells showed a marked preference for H-2K^b compared to H-2D^b compatibility. We propose that the VSV and H-2 antigens are molecularly independent entities in the unperturbed target cell membrane but that the antibody-induced clustering of the VSV antigen causes a selective and unidirectional co-redistribution (which we designate as syn-capping) of H-2K^b with the VSV antigen clusters. It is suggested that such a T-cell-induced syn-capping process involving an antigen and an H-2 molecule on the target cell may play a critical role in the mechanism of cytotoxic T-cell killing.