Targeted inhibition of HK2 expression in pancreatic ductal adenocarcinoma reprogrammes the immune microenvironment by regulating CCL5-mediated CD8+ T cell infiltration

Background Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to immune checkpoint inhibitor (ICI) therapy due to its highly immunosuppressive tumor microenvironment (TME). Methods Key regulatory genes were screened using bioinformatics analysis of TCGA and KEGG datasets. The expression patterns of HK2 were analyzed by single-cell sequencing and immunohistochemistry. The HK2-CCL5-CD8 + T-cell axis was evaluated using mouse pancreatic cancer models, in vitro co-culture systems, Transwell assays, RNA sequencing, and flow cytometry. The relationship between HK2 and anti-PD-1 therapy was also assessed. Results Hexokinase 2 (HK2), a rate-limiting enzyme of glycolysis, is a key regulator in tumor immune evasion. HK2 is highly expressed in PDAC tumor cells. Its expression is significantly associated with CD8 + T-cell infiltration in the tumor microenvironment and disease progression. Inhibiting HK2 expression significantly promotes C C motif chemokine ligand 5 (CCL5) secretion by pancreatic cancer cells, which enhances the recruitment of CD8 + T-cell. Moreover, inhibiting HK2 enhance antitumor efficacy of anti-PD-1 therapy in PDAC. Mechanistically, ROS scavenging with NAC reverses the CCL5 upregulation caused by HK2 inhibition, which in turn affects CD8 + T-cell infiltration. Conclusion Our study reveals a novel HK2-CCL5 axis that regulates CD8 + T-cell recruitment and shapes the immune microenvironment in PDAC.