Inducing pyroptosis in cancer cells holds great potential in cancer immunotherapy. Lipopolysaccharide (LPS)-sensing noncanonical pathways are an important mechanism of pyroptosis to eliminate damaged cells, which has not yet been explored for cancer immunotherapy. Here, we utilize bacterial outer membrane vesicles (OMVs) as a natural LPS carrier to trigger a noncanonical pyroptosis pathway for immunotherapy. To address the concern of systemic toxicity, molecule engineered OMVs were designed by equipping DNA aptamers on the OMVs (Apt-OMVs). In addition to improving capacity to target tumors, Apt-OMVs also took advantage of the spherical nucleic acid structure to shield OMVs against nonspecific immune recognition and evade immunogenicity. The selective pyroptosis enhanced tumor immunogenicity, not only promoting the infiltration of effector T cells but also reducing the amount of immunosuppressive regulatory T cells, which remarkably suppressed tumor growth. This work reports the first pyroptosis inducer by the noncanonical pathway, offering inspiration for safe and efficient pyroptosis-mediated immunotherapy.
Keywords: aptamer; bacterial outer membrane vesicles; noncanonical pathway; safe immunotherapy; targeting pyroptosis.