Depletion of conventional CD4+ T cells is required for robust priming and dissemination of tumor antigen-specific CD8+ T cells in the setting of anti-CD4 therapy

CD8 T cells are potent anti-tumor mediators. We analyzed CD8 T cells from B16 tumor-draining lymphnodes from mice receiving one of three different treatments. Overall design: Mice were induced with 10,000 Pmel(thy1.1+) cells on D-1, and 200,000 B16 tumor cells intradermally on D0. Mice were then separated into 3 groups: 5 untreated, 5 anti-CD4 treated, and 5 ICB(anti-PD1 and anti-CTLA4) treated. Mice were sacrificed 12 days later and tumor-draining lymph nodes were harvested. Cells were stained with unique hashtag antibodies for (HTO). We sorted CD62Llo, CD44hi CD8+ and CD44hi, Thy1.1+ Pmel cells from each pooled group by FACS.