Figure 1.

In vivo PD-L1 blockade in combination with DCLV immunization increased the frequency of HIV-1 Gag-specific CD8⁺ T cells. Two weeks after DCLV-Gag vaccination and treatment with either αPD-L1 or isotype antibody, (a) the number of Gag-specific CD8⁺ T cells in splenocytes was measured by H2-K^d-AMQMLKETI-PE tetramer and CD44 staining, and (b) frequency of IFN-γ-producing cells was assessed by ELISPOT. (c) Representative FACS plots showing the Gag tetramer⁺ CD8⁺ T cell population in spleen (SP) and lymph nodes (LN). Each group consisted of four mice. P values were calculated using one-way Anova followed by a Bonferroni nonparametric posttest (ns, not significant; ***P < 0.001; **P < 0.01; *P < 0.05). The data are representative of two independent experiments. DCLV, dendritic cell-directed lentiviral vector; ELISPOT, enzyme-linked immunosorbent spot; HIV, human immunodeficiency virus; LN, lumph node; PD-L1, programmed death 1 ligand; SP, spleen.