CCL20 secreted by KRT15high tumor Cells promotes tertiary lymphoid structure formation and enhances anti-PD-1 therapy response in HPV+HNSCC

TL;DR

HPV-positive head and neck cancer cells secrete CCL20, which helps form immune structures that improve response to immunotherapy.

Contribution

Discovery that CCL20 from KRT15high tumor cells promotes TLS formation and enhances anti-PD-1 therapy in HPV+ HNSCC.

Findings

HPV+ HNSCC tumors have more mature tertiary lymphoid structures (TLS) than HPV- tumors.

KRT15high tumor cells in HPV+ HNSCC secrete CCL20, which attracts TLS-associated immune cells.

CCL20 treatment in mice promotes TLS formation and improves anti-PD-1 therapy effectiveness.

Abstract

Tertiary lymphoid structures (TLS) are associated with an improved response to Immune checkpoint therapy (ICT) in head and neck squamous cell carcinoma (HNSCC). Human papillomavirus (HPV) infection constitutes a high-risk factor for HNSCC carcinogenesis. However, its role in TLS formation has yet to be elucidated. Herein, immunohistochemical (IHC) analysis from 59 HNSCC patients revealed a higher prevalence of mature TLS in HPV-positive (HPV+) HNSCC compared to HPV-negative (HPV-) cases. Furthermore, integrated analysis of single-cell RNA sequencing, spatial transcriptomics, and RNA-seq data indicated that TLS-positive tumors were characterized by an expanded population of KRT15high tumor cells in HNSCC. IHC and cytological experiments confirmed upregulation of KRT15 in HPV+HNSCC tumor cells, which also showed high expression of cancer stem cell marker genes. These KRT15high stem-like tumor cells specifically secreted CCL20, which was related to the infiltration of TLS-associated immune cells in HPV+HNSCC. Murine models confirmed that CCL20 treatment promoted TLS formation and enhanced the efficacy of anti-PD-1 therapy. Multiplex immunofluorescence showed that TLS provided specialized microenvironments that supported the proliferation of CD39+PD-1+CD8+T cells. Collectively, our findings proposed that CCL20 secreted by HPV-infected KRT15high tumor cells promoted TLS formation, thereby enhancing anti-PD-1 therapy responses in HPV+HNSCC. This study provides mechanistic insights into HPV-mediated TLS development and supports precision immunotherapeutic strategies for HNSCC.

Figures