fig2

Figure 2. Intratumoral SyBV immunization results in complete regression of anti-PD-1-resistant melanoma. (A) Study design for therapeutic immunization with SyBV (top panel). Mice were i.t. immunized with SyBV (10⁹ or 10¹⁰) six times with 3-day intervals between injections following B16F10 inoculation. An anti-PD-1 antibody (100 µg) was given i.p. 1 day prior to immunization with SyBV. Tumor growth was monitored every 2-3 days (bottom panel). n = 9/group. Data are presented as the mean ± SEM. ^*P < 0.05, ^***P < 0.001 by Kruskal-Wallis analysis of variance with Dunn’s multiple comparison test; (B-E) Each individual tumor growth curve [(B) sham; (C) anti-PD-1 antibody; (D) SyBV (10⁹) plus anti-PD-1 antibody; (E) SyBV (10¹⁰) plus anti-PD-1 antibody] of mice shown in (A) (n = 9/group). Created with BioRender (2026). SyBV: Synthetic bacterial vesicle; PD-1: programmed cell death protein 1; i.t.: intratumoral; i.p.: intraperitoneal; SEM: standard error of the mean.