Plasma membranes from influenza virus-infected cells induce in vitro human secondary virus-specific cytotoxic T lymphocyte responses.

Influenza A virus-specific cytotoxic T lymphocytes (CTL) were induced by incubating human peripheral blood mononuclear cells with membranes prepared from influenza A virus-infected cells. The response obtained was equivalent to that given after sensitization in vitro with influenza A virus-infected lymphocytes. It was shown that this response was only obtained when stimulating membrane fragments and responding cells shared HLA-A or -B locus antigens. In order to analyse further the nature of the activating antigen, the membrane fragments were solubilized with detergent and then reconstituted by dialysing it out. This treatment destroyed their ability to stimulate virus-specific CTL although similar treatment of membranes from uninfected cells did not affect their capacity to stimulate a xenogeneic mouse CTL response. Liposomes constructed to contain defined virus and cell surface antigens also failed to stimulate CTL. These findings suggest that secondary induction of influenza virus-specific CTL in vitro requires the presence of the correct HLA antigen and that the virus-membrane association is irreversibly destroyed by detergent treatment.