Characterization of the adaptive immune response in a mouse model for HPV-positive head and neck squamous cell carcinoma with implications to human disease.

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with a poor prognosis for survival. Risk factors include alcohol and tobacco abuse and infection with human papilloma virus (HPV). To enhance anti-tumor immune responses immunotherapeutic approaches are approved for recurrent metastatic disease but only approx. 20% of patients respond to checkpoint blockade of the PD-1/PD-L1 axis. Therefore, preclinical research is needed to better understand molecular and cellular processes and to identify new therapeutic targets. Immunocompetent mouse models can serve these purposes but only few are currently available for HPV-positive HNSCC. Here, we established a mouse cell line overexpressing the oncogenes E6/E7 of the HPV16 genome as well as a constitutively active form of H-Ras and studied the anti-tumor immune response upon orthotopic tumor growth at the floor of the mouth. Moreover, we analyzed the same immunoregulatory pathways in samples of HPV-positive cancer patients. T cells in the tumor of mice and humans exhibited high expression of CD39 and CD73, two ectoenzymes involved in the production of immunosuppressive adenosine from ATP, along with increased expression of PD-1, LAG-3 and GITR. Additionally, B cell responses were elevated in tumor-bearing mice, seen as an increase of germinal center, immunoregulatory marginal zone and follicular B cell subtypes. Taken together, this study suggests that the generated mouse model shares characteristics with human disease and can thus be used as a platform to study anti-tumor responses in HPV-positive HNSCC which will help to identify novel therapeutic targets.

Oliveri F ，Neher L ，Pscheid R ，Sewald I ，Gowdavally S ，Betzler AC ，Hallitsch J ，Greve J ，Laban S ，Schmid S ，Hoffmann TK ，Schuler PJ ，Brunner C ... -  《-》

Differential tumor immune microenvironment coupled with tumor progression or tumor eradication in HPV-antigen expressing squamous cell carcinoma (SCC) models.

Human papilloma virus (HPV) is an etiological factor of head and neck squamous cell carcinoma (HNSCC). To investigate the role of HPV antigen in anti-tumor immunity, we established mouse models by expressing HPV16 E6 and E7 in a SCC tumor cell line. We obtained two HPV antigen-expressing clones (C-225 and C-100) transplantable into C57BL/6 recipients. We found that C-225 elicited complete eradication in C57BL/6 mice (eradicated), whereas C-100 grew progressively (growing). We examined immune tumor microenvironment (TME) using flow cytometry and found that eradicated or growing tumors exhibited differential immune profiles that may influence the outcome of anti-tumor immunity. Surprisingly, the percentage of CD8 and CD4 tumor-infiltrating lymphocytes (TILs) was much higher in growing (C-100) than eradicated (C-225) tumor. However, the TILs upregulated PD-1 and LAG-3 more potently and exhibited impaired effector functions in growing tumor compared to their counterparts in eradicated tumor. C-225 TME is highly enriched with myeloid cells, especially polymorphonuclear (PMN) myeloid-derived suppressor cells (MDSC), whereas the percentage of M-MDSC and tumor-associated macrophages (TAMs) was much higher in C-100 TME, especially M2-TAMs (CD206+). The complete eradication of C-225 depended on CD8 T cells and elicited anti-tumor memory responses upon secondary tumor challenge. We employed DNA sequencing to identify differences in the T cell receptor of peripheral blood lymphocytes pre- and post-secondary tumor challenge. Lastly, C-225 and C-100 tumor lines harbored different somatic mutations. Overall, we uncovered differential immune TME that may underlie the divergent outcomes of anti-tumor immunity by establishing two SCC tumor lines, both of which express HPV16 E6 and E7 antigens. Our experimental models may provide a platform for pinpointing tumor-intrinsic versus host-intrinsic differences in orchestrating an immunosuppressive TME in HNSCCs and for identifying new targets that render tumor cells vulnerable to immune attack.

Shivarudrappa AH ，John J ，Vashisht M ，Ge H ，Liu S ，Chen J ，Siddoway K ，Dong R ，Chen Z ，Wang JH ... -  《Frontiers in Immunology》

Impact of T Cell Exhaustion and Stroma Senescence on Tumor Cell Biology and Clinical Outcome of Head and Neck Squamous Cell Carcinomas.

Brust LA ，Vorschel M ，Körner S ，Knebel M ，Kühn JP ，Wemmert S ，Smola S ，Wagner M ，Schick B ，Linxweiler M ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Inhibition of the chemokine receptors CXCR1 and CXCR2 synergizes with docetaxel for effective tumor control and remodeling of the immune microenvironment of HPV-negative head and neck cancer models.

Relapsed head and neck squamous cell carcinoma (HNSCC) unrelated to HPV infection carries a poor prognosis. Novel approaches are needed to improve the clinical outcome and prolong survival in this patient population which has poor long-term responses to immune checkpoint blockade. This study evaluated the chemokine receptors CXCR1 and CXCR2 as potential novel targets for the treatment of HPV-negative HNSCC. Expression of IL-8, CXCR1, and CXCR2 was investigated in HNSCC tissues and human cell line models. Inhibition of CXCR1/2 with the clinical stage, small molecule inhibitor, SX-682, was evaluated in vitro and in vivo using human xenografts and murine models of HNSCC, both as a monotherapy and in combination with the taxane chemotherapy, docetaxel. High levels of IL-8, CXCR1, and CXCR2 expression were observed in HPV-negative compared to HPV-positive HNSCC tumors or cell lines. Treatment of HPV-negative HNSCC cell lines in vitro with SX-682 sensitized the tumor cells to the cytotoxic activity of docetaxel. In vivo, treatment of HNSCC xenograft models with the combination of SX-682 plus docetaxel led to strong anti-tumor control resulting in tumor cures. This phenomenon was associated with an increase of microRNA-200c and a decreased expression of its target, tubulin beta-3, a protein involved in resistance to microtubule-targeting chemotherapies. In vivo treatment of a murine syngeneic model of HNSCC with SX-682 plus docetaxel led to potent anti-tumor efficacy through a simultaneous decrease in suppressive CXCR2+ polymorphonuclear, myeloid-derived suppressor cells and an increase in cytotoxic CD8+ T cells in the combination therapy treated tumors compared to controls. This study reports, for the first time, mechanistic findings through which the combination of CXCR1/2 inhibition and docetaxel chemotherapy exhibits synergy in models of HPV-negative HNSCC. These findings provide rationale for the use of this novel combination approach to treat HPV-negative HNSCC patients and for future combination studies of CXCR1/2 inhibition, docetaxel, and immune-based therapies.

Horn LA ，Lind H ，Fousek K ，Qin H ，Rajabian N ，Angstadt S ，Hsiao-Sanchez N ，Medina-Enriquez MM ，Kelly MD ，Allen CT ，Hammoudeh SM ，Weigert R ，Maeda DY ，Zebala JA ，Palena C ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

DEK promotes HPV-positive and -negative head and neck cancer cell proliferation.

Adams AK ，Hallenbeck GE ，Casper KA ，Patil YJ ，Wilson KM ，Kimple RJ ，Lambert PF ，Witte DP ，Xiao W ，Gillison ML ，Wikenheiser-Brokamp KA ，Wise-Draper TM ，Wells SI ... -  《-》