Bacteriophages and cancer

Abstract

Bacteriophages can be used effectively to cure bacterial infections. They are known to be active against bacteria but inactive against eukaryotic cells. Nevertheless, novel observations suggest that phages are not neutral for higher organisms. They can affect physiological and immunological processes which may be crucial to their expected positive effects in therapies. Bacteriophages are a very differentiated group of viruses and at least some of them can influence cancer processes. Phages may also affect the immunological system. In general, they activate the immunological response, for example cytokine secretion. They can also switch the tumor microenvironment to one advantageous for anticancer treatment. On the other hand, bacteriophages are used as a platform for foreign peptides that may induce anticancer effects. As bacterial debris can interfere with bacteriophage activity, phage purification is significant for the final effect of a phage preparation. In this review, results of the influence of bacteriophages on cancer processes are presented which have implications for the perspective application of phage therapy in patients with cancer and the general understanding of the role of bacteriophages in the human organism.

Phage treatment of human infections

“…Indeed, a group led by Górski have provided evidence of a positive impact of phages on immune system functioning 6 and have explored potential phage anti-tumor properties mediated through observed shifts in levels of various cytokines as a consequence of interactions between extra decorative head proteins with surface proteins of certain immune-system cells. 119 Note that this does not involve nor imply an ability of phages to infect mammalian cells.…”

Enhancing and initiating phage-based therapies

“…82 We note that, independent of DDV-activity, phages have been found to have additional, probably immune stimulatory, therapeutic effects on tumors. 83 The loading studies performed here are the first to indicate the possibility of an in vivo-generated, highly uniform, stable, non-leaky, gated DDV. In addition, remote loading via an osmotic pressure gradient should be possible with MLD capsid II.…”

Phenotypic Evolution of Therapeutic Salmonella enterica Serovar Typhimurium after Invasion of TRAMP Mouse Prostate Tumor

“…The initial isolates recovered from the prostate tumor maintained their bacteriophage resistance, while those from the liver and spleen lost their resistance to some phage. We find this to be a promising attribute of our therapeutic strain, as it illustrates not only its phenotypic robustness under physiological conditions in the tumor but also its potential compatibility with current therapeutic approaches that incorporate bacteriophages for their antitumor usage or for their ability to display peptides for anticancer use (12). Our therapeutic strain CRC2631 includes the deletion of rfaH , which changes the nature of the cell membrane by reducing the amount of available wild-type lipopolysaccharide (LPS) and dramatically reducing phage susceptibility, as many phage bind to bacterial LPS before infection (13).…”