University of Pittsburgh Medical Center UPMC Hillman Cancer Center, Division of Hematology and Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
Front Immunol. 2024 Jul 11;15:1405318. doi: 10.3389/fimmu.2024.1405318. eCollection 2024.
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.
人乳头瘤病毒 (HPV) 是头颈部鳞状细胞癌 (HNSCC) 的病因。为了研究 HPV 抗原在抗肿瘤免疫中的作用，我们通过在 SCC 肿瘤细胞系中表达 HPV16 E6 和 E7 建立了小鼠模型。我们获得了两个可移植到 C57BL/6 受体中的 HPV 抗原表达克隆（C-225 和 C-100）。我们发现 C-225 在 C57BL/6 小鼠中完全消除（根除），而 C-100 则逐渐生长（生长）。我们使用流式细胞术检查免疫肿瘤微环境 (TME)，发现根除或生长的肿瘤表现出不同的免疫特征，这可能影响抗肿瘤免疫的结果。令人惊讶的是，生长（C-100）肿瘤中的 CD8 和 CD4 肿瘤浸润淋巴细胞 (TIL) 的百分比明显高于根除（C-225）肿瘤。然而，与根除肿瘤中的 TIL 相比，生长肿瘤中的 TIL 上调 PD-1 和 LAG-3 的能力更强，并且表现出受损的效应功能。C-225 TME 富含髓样细胞，特别是多形核 (PMN) 髓源抑制细胞 (MDSC)，而 C-100 TME 中 M-MDSC 和肿瘤相关巨噬细胞 (TAMs) 的百分比更高，特别是 M2-TAMs (CD206)。C-225 的完全根除取决于 CD8 T 细胞，并在二次肿瘤挑战时引发抗肿瘤记忆反应。我们采用 DNA 测序来鉴定二次肿瘤挑战前后外周血淋巴细胞 T 细胞受体的差异。最后，C-225 和 C-100 肿瘤系具有不同的体细胞突变。总的来说，我们通过建立两个表达 HPV16 E6 和 E7 抗原的 SCC 肿瘤系，揭示了可能导致抗肿瘤免疫不同结果的不同免疫 TME。我们的实验模型可能为确定 HNSCC 中调节免疫抑制性 TME 的肿瘤内在与宿主内在差异以及确定使肿瘤细胞易受免疫攻击的新靶点提供了一个平台。
