Back

Anti-tumor Efficacy of in situ Vaccination Using Bacterial Outer Membrane Vesicles

Caproni, E.; Corbellari, R.; Tomasi, M.; Isaac, S. J.; Tamburini, S.; Zanella, I.; Grigolato, M.; Gagliardi, A.; Benedet, M.; Baraldi, C.; Croia, L.; Di Lascio, G.; Valensin, S.; Bellini, E.; Parri, M.; Grandi, A.; Grandi, G.

2023-04-07 cancer biology
10.1101/2023.04.07.536036 bioRxiv
Show abstract

In situ vaccination (ISV) is a promising cancer immunotherapy strategy, consists in the intratumoral administration of immunostimulatory molecules (adjuvants). The rationale is that tumor antigens are abundant at the tumor site and therefore to elicit an effective anti-tumor immune response all is needed is an adjuvant, which can turn the immunosuppressive environment into an immunologically active one. Bacterial Outer Membrane Vesicles (OMVs) are potent adjuvants since they contain a number of microbe-associated molecular patterns (MAMPs) naturally present in the outer membrane and in the periplasmic space of Gram-negative bacteria. Therefore, they appear particularly indicted for ISV. In this work we first show that the OMVs from E. coli BL21(DE3){Delta}60 strain promote a strong anti-tumor activity when intratumorally injected into the tumors of two different mouse models. Tumor inhibition correlates with a rapid infiltration of DCs and NK cells. We also show that the addition of neo-epitopes to OMVs synergizes with the vesicle adjuvanticity, as judged by a two-tumor mouse models. Overall, our data support the use of the OMVs in ISV and suggests that ISV efficacy could benefit from the addition of properly selected tumor-specific neo-antigens.

Matching journals

The top 8 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.