Human papillomavirus subtype 16 (HPV16) is the primary cause of an increasing number of head and neck squamous cell carcinomas (HNSCC), providing strong rationale for T-cell immune therapies against HPV HNSCC. Here we assess immunogenicity of HPV16-specific CD8 T cells (CTL) and characterize HPV-specific mechanisms of T-cell dysfunction. We identified 16 strong and 29 moderately immunogenic CTL-epitopes from HPV16 E2, E6, and E7 antigens restricted by 12 common HLA class I alleles. E2-specific CTL-reactivity was higher in patients with HPV HNSCC than in healthy controls (>3-fold; = 0.026). Patient-derived E2, E6, and E7 peripheral CTLs exhibited heterogeneity in dysfunctional phenotypes. Immunogenomic analyses of 119 HNSCC transcriptomes revealed high T-cell infiltration and dysfunction in HPV HNSCC and correlation of HPV antigen expression with T-cell exhaustion gene signatures. Indoleamine 2,3-dioxygenase (IDO-1) was strongly expressed in HPV HNSCC versus HPV HNSCC ( = 0.001) and correlated with E7 expression ( = 0.84; = 0.033). Combination treatment with PD-1 blockade and IDO-1 inhibition overcame profound CTL-dysfunction, enhancing HPV HNSCC sensitivity to CTL-cytotoxicity (up to 10-fold in E7-CTLs, = 0.011). Our findings implicate mechanisms of T-cell escape in HPV HNSCC, wherein high tumoral HPV-antigen load results in high expression of immune dysfunction genes on tumor cells (e.g., IDO-1), and dysfunction of HPV-specific CTLs (e.g., E7, E2-CTLs). The HPV16 CTL-epitopes identified in this study, in combination with blockade of HPV HNSCC-specific PD-1/IDO-1 checkpoints, may be useful for targeted immunotherapy. This study evaluates the HPV antigen T-cell immunogenicity role of inhibitory receptors and other exhaustion markers in the cytotoxic function of HPV antigen-specific CTLs and identifies combined inhibition of PD-1/IDO-1 as a strategy to enhance CTL targeting of HPV HNSCC. .

Background: Given its role in the disease pathophysiology, inhibition of vascular endothelial growth factor (VEGF)-mediated angiogenesis has received attention as a potential strategy to reduce epistaxis associated with hereditary hemorrhagic telangiectasia (HHT). In this study we evaluated the efficacy of a submucosal injection of bevacizumab, a VEGF inhibitor, in reducing the severity of epistaxis and improving quality of life when given at the time of operative electrocautery. Methods: This randomized, double-blinded, placebo-controlled trial was conducted at a single institution from 2014 to 2019. Patients scheduled to undergo operative bipolar electrocautery of nasal telangiectasias were randomized to receive a submucosal injection of saline or bevacizumab at time of surgery. Surveys to assess epistaxis severity and quality of life (QOL), including the Epistaxis Severity Score (ESS) and the 12-item Short Form (SF-12), were administered preoperatively and at 1, 2, 4, and 6 months postoperatively. The minimal clinically important difference (MCID) of the ESS instrument is reported to be 0.71. Results:Of 39 patients enrolled, 37 (94.9%) completed the study. The saline group demonstrated a reduced ESS vs baseline at 1 (−1.2; p = 0.01) and 4 (−1.2; p = 0.05) months postprocedure. The bevacizumab group demonstrated a reduced ESS score vs baseline at 1 (−2.3; p < 0.001), 2 (−2.3; p < 0.001), 4 (−2.0; p = 0.003), and 6 (−1.3; p = 0.05) months postprocedure. The additive benefit of bevacizumab over saline exceeded the MCID at 1, 2, and 4 months, but the difference was not statistically significant. Conclusion:The addition of a single treatment of submucosal bevacizumab may be associated with additional clinically meaningful benefit for up to 4 months when compared with electrocautery alone.

<p>Summary of strong HLA-binders from all HPV16-genes for TCGA/UM cohort patient HLA alleles</p>

<p>Summary of all predicted candidate HPV16-E2, E6 and E7 epitopes used for experiments.</p>

<p>Gene signatures for ssGSEA used in this study.</p>