Intravaginal live attenuated Salmonella increase local antitumor vaccine-specific CD8⁺ T cells

We have recently reported that the intravaginal instillation of synthetic Toll-like receptor 3 (TLR3) or TLR9 agonists after a subcutaneous vaccination against human papillomavirus E7 highly increases (~5-fold) the number of vaccine-specific CD8⁺ T cells in the genital mucosa of mice, without affecting E7-specific systemic responses. Here, we show that the instillation of live attenuated Salmonella enterica serovar Typhimurium similarly, though more efficiently (~15- fold), increases both E7-specific and total CD8⁺ T cells in the genital mucosa. Cancer immunotherapeutic strategies combining vaccination with local immunostimulation with live bacteria deserve further investigations.