Effects of helicobacter pylori on tumor microenvironment and immunotherapy responses

Abstract

Helicobacter pylori is closely associated with gastric cancer. During persistent infection, Helicobacter pylori can form a microenvironment in gastric mucosa which facilitates the survival and colony formation of Helicobacter pylori. Tumor stromal cells are involved in this process, including tumor-associated macrophages, mesenchymal stem cells, cancer-associated fibroblasts, and myeloid-derived suppressor cells, and so on. The immune checkpoints are also regulated by Helicobacter pylori infection. Helicobacter pylori virulence factors can also act as immunogens or adjuvants to elicit or enhance immune responses, indicating their potential applications in vaccine development and tumor immunotherapy. This review highlights the effects of Helicobacter pylori on the immune microenvironment and its potential roles in tumor immunotherapy responses.

Effect of Antacid Use on Immune Checkpoint Inhibitors in Advanced Solid Cancer Patients: A Systematic Review and Meta-analysis

“…In short, the influence of PPIs on the immune system remains unclear. We propose that PPIs may cause immune system dysfunction through their own function or through changes in the gut microbiota 97,98. Further exploration is needed to clarify the mechanism.…”

“…We propose that PPIs may cause immune system dysfunction through their own function or through changes in the gut microbiota. 97,98 Further exploration is needed to clarify the mechanism. For ORR and irAEs, the pooled analysis demonstrated that PPI use did not affect ORR or irAEs in advanced cancer patients treated with ICIs.…”

Therapeutic potential and limitations of curcumin as antimetastatic agent

“…Beside significantly reducing tumour mass, and cell migration, another promising effect of curcumin could also be that it could target tumour microflora. It is well known that Helicobacter pylori is strongly associated with the induction and development of gastric tumours, which includes metastatic activity [291,292]. It was reported that curcumin displayed potent activity against various strains of Helicobacter pylori (MIC ~ 5-50 μg/mL) [293,294].…”

Tissue-resident memory T cells in gastrointestinal tumors: turning immune desert into immune oasis

“…and Epstein-Barr virus (EBV) are the main infection-related factor (92)(93)(94). H. pylori can inhibit the CD8 + CTLs by myeloid-derived suppressor cells (MDSCs) and induce the up-regulated expression of PD-L1 of tumor epithelial cells and macrophages, thereby inducing the resistance of gastric cancer to ICB therapy against PD-1/PD-L1 (95,96). Xu et al have shown that the induction of Trm proliferation and differentiation can enhance the local immune response to H. pylori (97).…”