Abstract Helicobacter pylori (Hp) bacteria successfully establishes chronic infection leading to chronic gastritis, peptic ulcer disease (PUD), and gastric cancer (GC). Since we have previously shown that Hp hijacks expression of checkpoint immunoregulators (i.e., PD-L1), we hypothesized that strains from different gastric pathologies differ in their ability to evade the host response. We used human gastric organoids (hGOs), which recapitulate polarized epithelium, gastric gland and pit cell markers observed in the stomach. We cultured hGOs in transwell inserts which were exposed to Hp on the apical surface and cultured with naïve T cells on the basolateral side of polarized epithelial cells, thereby reproducing the interactions observed in vivo. After 7 days of culture, we recovered all cells and evaluated levels of PD-L1, B7-H3, B7-H4, and CTLA4; and in CD4+ T cells markers of Th1, Th2, Th17 and Treg. Infection of hGOs with Hp strains isolated from cases of gastritis, PUD or GC, all led to increased expression of negative immune checkpoint regulators, predominantly PD-L1, which binds PD-1 on T cells and promotes loss of effector functions, apoptosis, and reduced T cell-target cell contact. Interestingly, PUD strains are the stronger inducers of PD-L1 and GC strains were the lowest inducers of Th1 cells (Tbet+, IFNγ+), which suggest that different strains differ in their orchestration of the host response, which may contribute to the type of pathology elicited. Our data suggest that this co-culture system to evaluate expression of immune checkpoint regulators and CD4+ T cell differentiation in the context of strains comparison may provide insights in differential expression of candidate biomarkers of disease and future therapies.
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