Spatial and functional dissection of cancer-associated fibroblasts-mediated immune modulation in H. pylori-associated gastric cancer
Bonan Chen, Hongzhen Tang, Xiaohong Zheng, Fuda Xie, Peiyao Yu, Yang Lyu, Tiejun Feng, Jialin Wu, Jingya Liu, Yi Xu, Alvin H.K. Cheung, Canbin Fang, Zhangding Wang, Shouyu Wang, Justin Chak Ting Cheung, Yujuan Dong, Ruoxi Tian, Yigan Zhang, Cheng Lu, Chi Chun Wong, Jun Yu, William Ka Kei Wu, Elke Burgermeister, Man Tong, Fengbin Zhang, Wei Kang, Kam Tong Leung, Ka‐Fai To
Abstract
Abstract Background Cancer-associated fibroblasts (CAFs) are key regulators of the tumor microenvironment, yet their spatial organization and immunomodulatory functions in H. pylori -associated gastric cancer (GC) remain incompletely understood. Methods We profiled formalin-fixed paraffin-embedded (FFPE) tumors from 71 GC patients using spatial transcriptomics and integrated single-cell RNA-seq from three independent cohorts (China, USA, and Singapore). CAF-immune cell colocalization was quantified by neighborhood enrichment and aggregation index score. Ligand-receptor inference and trajectory analysis resolved CAF signaling and state transitions. To delineate post-transcriptional control, ARE-motif scanning and expression correlations were combined with laser-assisted crosslinking and immunoprecipitation sequencing (LACE-seq) to nominate ZFP36 targets. Immune contexture and prognostic associations were evaluated using CIBERSORT-ABS and Kaplan-Meier analyses in The Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG) cohorts. Results We first defined the spatial distributions of the four CAF subtypes reported in prior studies and found that their immune associations varied across histologic and infection-defined GC subtypes. In H. pylori -positive tumors, THBS1⁺ CAFs were spatially enriched near regulatory T cells (Tregs) and were associated with local immunosuppression through WNT5-FZD interactions. In parallel, ZFP36 bound AU-rich elements within the FN1 3′ untranslated region (3'UTR), destabilizing FN1 mRNA and thereby diminishing FN1⁺ CAF-mediated cytotoxic T lymphocyte (CTL) activation. Together, these axes promoted Treg accumulation and suppression of CTL activation. Conclusions These findings reveal infection-associated stromal programs that shape the immune landscape in GC and highlight CAF-directed pathways as potential therapeutic targets in H. pylori -associated GC. Graphical abstract H. pylori -induced CAF-mediated immunosuppression in GC. 1. H. pylori infection triggers transcriptional reprogramming of CAFs within the tumor microenvironment of GC. 2. The CAF subset marked by THBS1 is spatially enriched adjacent to Tregs and facilitates their recruitment via WNT5-FZD ligand-receptor signaling. 3. The RNA-binding protein ZFP36 binds AU-rich elements in the FN1 3’UTR, destabilizing FN1 mRNA and thereby attenuating CTL activation. 4. The THBS1-WNT5 axis stabilizes Tregs, whereas the ZFP36-FN1 axis limits CTL activation, converging to drive local immunosuppression in H. pylori -positive GC.