Engineered immunostimulatory bacterial strains and uses thereof

Abstract

Provided are delivery immunostimulatory bacteria that have enhanced colonization of tumors, the tumor microenvironment and/or tumor-resident immune cells, and enhanced anti-tumor activity. The immunostimulatory bacteria are modified by deletion of genes encoding the flagella, or by modification of the genes so that functional flagella are not produced, and/or are modified by deletion of pagP or modification of pagP to produce inactive PagP product. As a result, the immunostimulatory bacteria are flagellin− and/or pagP−. The immunostimulatory bacteria optionally have additional genomic modifications so that the bacteria are adenosine or purine auxotrophs. The bacteria optionally are one or more of asd−, purI−, and msbB−. The immunostimulatory bacteria, such as Salmonella species, are modified to encode immunostimulatory proteins that confer anti-tumor activity in the tumor microenvironment, and/or are modified so that the bacteria preferentially infect immune cells in the tumor microenvironment, or tumor-resident immune cells, and/or are modified to induce less cell death in immune cells than in other cells. Also provided are methods of inhibiting the growth or reducing the volume of a solid tumor by administering the immunostimulatory bacteria.

Dependencies are inferred from the claim text.