CD161 expression of TRM cells counteracts the HPV-associated clinical benefit in oropharyngeal cancer immunotherapy

Oropharyngeal squamous cell carcinoma (OPSCC), a distinct head and neck cancer subtype that develops in the oropharynx, is well known to be categorized into human papillomavirus induced (HPV+) and non-HPV induced (HPV-). While HPV+ OPSCC is reported to be clinically advantageous compared to HPV- OPSCC, the heterogeneous responses in HPV+ OPSCC during immunotherapy treatment have not been well characterized at the molecular level. In this study, we assess both tumor and immune cells of the OPSCC tumor microenvironment (TME) via single-cell RNA sequencing (scRNA-seq) and single-cell TCR sequencing (scTCR-seq). By dissecting the transcriptome of OPSCC tumor cells, we find that cancer cell transcriptional diversity may be a strong factor in negating HPV associated clinical benefits. By assessing immune cells, we observed molecular antiviral and anti-tumor characteristics of T cells that is associated with HPV infection, and key cell-cell interaction differences among resident memory T cells (Trm), follicular helper T cells, and B cells. Importantly, we identify a novel molecular state within the HPV+ OPSCC that is distinguished by the expression KLRB1 (CD161) in the Trm that inhibits anti-tumor activity, which may further explain the heterogeneous clinical benefits of HPV+OPSCC. Association of KLRB1 expression of Trm and immunotherapy outcome was confirmed via immunofluorescence analysis, suggesting CD161 as a novel therapeutic target to improve cancer treatment of HPV+ OPSCC.