The incidence of human papillomavirus (HPV)+ head and neck squamous cell carcinoma (HNSCC) has surpassed that of cervical cancer and is projected to increase rapidly until 2060. The co-evolution of HPV with transforming epithelial cells leads to the shutdown of host immune detection. Targeting proximal viral nucleic acid-sensing machinery is an evolutionarily conserved strategy among viruses to enable immune evasion. However, E7 from the dominant HPV subtype-16 in HNSCC shares low homology with HPV18 E7, which was shown to inhibit the STING-DNA-sensing pathway. The mechanisms by which HPV16 suppresses STING remain unknown. Recently, we characterized the role of the STING-type-I interferon (IFN-I) pathway in maintaining immunogenicity of HNSCC in mouse models. Here we extended those findings into clinical domain utilizing tissue microarrays and machine-learning-enhanced profiling of STING signatures with immune subsets. We additionally showed that HPV16 E7 employs distinct mechanisms than HPV18 E7 to antagonize the STING pathway. We identified NLRX1 as a critical intermediary partner to facilitate HPV16 E7-potentiated STING turnover. The depletion of NLRX1 resulted in significantly improved IFN-I-dependent T-cell infiltration profiles and tumor control. Overall, we discovered a unique HPV16 viral strategy to thwart host innate immune detection that can be further exploited to restore cancer immunogenicity.
Xiaobo Luo, Christopher R. Donnelly, Wang Gong, Blake R. Heath, Yuning Hao, Lorenza A. Donnelly, Toktam Moghbeli, Yee Sun Tan, Xin Lin, Emily Bellile, Benjamin A. Kansy, Thomas E. Carey, J. Chad Brenner, Lei Cheng, Peter J. Polverini, Meredith A. Morgan, Haitao Wen, Mark E. Prince, Robert L. Ferris, Yuying Xie, Simon Young, Gregory T. Wolf, Qianming Chen, Yu L. Lei