Potential links between the microbiota and T cell immunity determine the tumor cell fate

Abstract

The central role of the microbiota as a pivotal factor regulating anti-tumor immune responses has recently been appreciated. Increasing evidence has put a spotlight on the connection of microbiota to T cells, by showing impaired effector and/or memory responses in germ-free (GF) mice or in the presence of dysbiotic communities, and association with tumor growth and overall survival (OS). These observations also have significant implications for anti-tumor therapy and vaccination, suggesting that the communication between T cells and the microbiota involves soluble mediators (microbiota-derived metabolites) that influence various functions of T cells. In addition, there is growing appreciation of the role of bacterial translocation into the peritumoral milieu from the intestinal tract, as well as of locally developed tumor microbial communities, spatially separated from the gut microbiota, in shaping the tumor microbiome. Collectively, these findings have added new support to the idea that tonic inputs mirroring the existence of tumor microbiome could regulate the function of tumor-infiltrating T cells and tissue-resident memory T (TRM) cells. In this review, we focus on recent advances and aspects of these active areas of investigation and provide a comprehensive overview of the unique mechanisms that play a pivotal role in the regulation of anti-tumor immunity by the microbiota, some of which could be of particular relevance for addressing problems caused by tumor heterogeneity. It is our hope that this review will provide a theoretical foundation for future investigations in this area.

Differential microbiota network according to colorectal cancer lymph node metastasis stages

“…In consideration of the correlation between Cecembia and Treg cells, as well as the elevated abundance of Cecembia and improved survival among N1 patients, these findings collectively indicate that Cecembia has the potential to influence the shift in the immunosuppressive function of Tregs at the primary site of N1 CRC. Recent studies support the notion that the gut microbiome and its metabolites possess the capacity to regulate the anti-tumor immune response through modulation of T cell activation, exerting either promotional or inhibitory effects [28,29].…”

Microbiome Sex-Related Diversity in Non-Muscle-Invasive Urothelial Bladder Cancer

“…Firstly, the Chao1 index, a measure of species richness, suggests that women harbour a less diverse microbial community in the bladder compared to men. This discrepancy in microbial richness could be indicative of differing microbial colonization patterns, immune responses, or hormonal influences between sexes [60][61][62]. One implication of the reduced taxa richness in women is the potential alteration of microbial community dynamics within the bladder microenvironment.…”

Drinking Water Microbiota, Entero-Mammary Pathways and Breast Cancer: Focus on Nontuberculous Mycobacteria

“…Gut dysbiosis can compromise the integrity of the intestinal barrier, allowing bacteria and microbial products to escape into circulation, which can trigger pro-inflammatory pathways, disrupting immune balance and fostering tumor development [136]. Pathogens are detected through pathogen-associated molecular patterns (PAMPs) by Toll-like receptors (TLRs), initiating signaling pathways that activate genes associated with immune response and inflammation.…”