Fig. 5.
γδ T-APCs cross-present live and inactivated virus. (A) Percentage of IFN-γ–producing M1p58-66 Tet+ T cells in response to γδ T-APCs incubated with increasing concentrations of live influenza virus. Results are expressed as mean ± SEM from three to seven independent experiments. (B) Blood CD8+ T cells were cocultured with virus-treated γδ T-APCs, and M1p58-66 Tet+ cells were quantified by FACS after 11 days. Controls included medium and M1 protein–loaded γδ T-APCs. One of three independent experiments is shown. (C) Residual efficiency of γδ T-APCs to cross-present virus (MOI 1) in the IFN-γ responder cell assay after pretreatment of γδ T-APCs with lactacystin (Left) or after processing of UV or heat-inactivated virus (Right). Data are presented as percentage of activity (mean ± SEM; n = 4–5). (D) Influenza-infected cells (flu-cells) were incubated with γδ T-APCs for 18 h, and cross-presentation was assessed as IFN-γ production by M1p58-66–specific CD8+ T cells (mean ± SEM; n = 4–7). Negative controls included noninfected cells (no flu), HLA-A2− γδ T-APCs, and virus-infected cells in the absence of γδ T-APCs. *P = 0.015; ***P = 0.0018.