Research staff have discovered a bacterial virus within intestinal microbiota that improves immunotherapy in cancer patients. The finding, which is published today in the journal Science, is the result of an extensive international study led by Laurence Zitvogel and Guido Kroemer from Gustave Roussy Hospital in Paris, and to which Professor Carlos López-Otín from the University of Oviedo and the University Institute of Oncology of Asturias ("IUOPA" by its Spanish acronym) contributed. This work represents a highly innovative approach that is aimed at improving promising cancer immunotherapy techniques. The authors initially relied on previous studies done by their laboratories that had shown that gut microbiota has the potential to alter highly significant aspects of human health - including susceptibility to cancer and increasing longevity.

 

Their work involved a thorough examination of the constituents of the intestinal microbiome of humans and mice, during which a protein fragment was found of a bacterial virus (bacteriophage 13144 of the bacterium Enterococcus hirae), similar to that of cellular proteins capable of stimulating the immune response based on T-lymphocytes.  Further studies revealed that this viral protein fragment was present in patients with kidney or lung cancer whose tumours were sensitive to immunotherapy treatment. Furthermore, introducing this viral protein fragment into the intestinal microbiome improved elimination of tumours in mice by boosting the anti-tumour immune response. The authors conclude that these results demonstrate the extraordinary - and as yet largely unknown - wealth of the constituents of intestinal microbiota in stimulating immune responses to cancer and other serious diseases in humans.