HEAD AND NECK SQUAMOUS CELL CARCINOMA

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。最近有强有力的证据表明，HPV与一组不同的头颈部鳞状细胞癌之间存在病因学联系，其特点是高危HPVDNA存在于肿瘤细胞核中。这些肿瘤绝大多数是HPV16阳性。由于病毒癌蛋白E6和E7在HPV相关癌症中持续表达，并且是肿瘤特异性抗原，HPV相关头颈部鳞状细胞癌(HPV-HNSCC)患者可能受益于旨在增强对HPV癌蛋白的细胞免疫反应的治疗策略。在临床前模型系统中，结核分枝杆菌热休克蛋白70(HSP70)与HPV16E7抗原的连接被证明显著增强了裸DNA疫苗的效力。与野生型E7 DNA疫苗相比，接种E7/HSP70 DNA的小鼠HPV16 E7特异性CD8+T细胞的频率至少增加了30倍，并对表达E7的肿瘤产生了显著的抗肿瘤作用。该疫苗对已建立的表达E7的小鼠肿瘤显示出显著的效力，下调主要组织相容性复合体(MHC)I类分子，这是一个重要的发现，因为相当大比例的晚期HNSCC显示MHC I类分子下调。重复DNA疫苗可诱导出不同性质的细胞毒性T淋巴细胞(CTL)，具有更高的亲和力和更好的抗肿瘤保护性作用。此外，在DNA疫苗中向E7(解毒)/HSP70中添加信号肽，显著提高了肌肉注射免疫方法的效果。产生了一个与Rb结合的关键残基突变的E7基因(称为E7 detox)，该基因不能与Rb结合，没有转化活性，但仍保持了强大的免疫原性。PNGVL4a DNA主干中的GMP级Sig-E7(排毒)/HSP70已在NIH快速干预开发计划的支持下用于临床试验。为评价HPV16-HNSCC患者肌肉注射E7(排毒)HSP70DNA疫苗的安全性、可行性和免疫学活性的初步证据，提出了一项开放标签、剂量递增试验。免疫学活性将通过ELISPOT、CTL、四聚体染色和细胞内细胞因子染色以及随后的流式细胞仪分析来评估E7特异性T细胞介导的免疫反应，以及通过测量HPV16E7抗体效价来评估体液免疫反应。该剂量被发现是安全的，可行的，并发展出免疫活性的证据，将在未来的第二阶段试验中进行研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Strong evidence of an etiologic association between HPV and a distinct subset of head and neck squamous cell carcinomas, distinguished by the presence of high-risk HPV DNA in tumor cell nuclei, has recently been reported. These tumors are overwhelmingly HPV16 positive. Because viral oncoproteins E6 and E7 are consistently expressed in HPV-associated cancers and are tumor-specific antigens, patients with HPV-associated head and neck squamous cell carcinoma (HPV-HNSCC) may benefit from therapeutic strategies designed to augment the cellular immune response to HPV oncoproteins. In preclinical model systems, linkage of Mycobacterium tuberculosis heat shock protein 70 (HSP70) to the HPV16 E7 antigen was demonstrated to significantly enhanced the potency of a naked DNA vaccine. Vaccination of mice with E7/HSP70 DNA increased the frequency of HPV16 E7-specific CD8+ T cells by at least 30-fold compared to vaccination with wild-type E7 DNA and generated a significant antitumor effect against an E7-expressing tumor. This vaccine demonstrated significant potency against established E7-expressing murine tumors with down-regulation of Major Histocompatibility Complex (MHC) class I molecules, an important finding given a significant proportion of advanced stage HNSCC exhibit down-regulation of MHC class I molecules. Repeated DNA vaccinations elicited qualitatively different cytotoxic T lymphocytes (CTL) with higher avidity and improved protective anti-tumor effects. Furthermore, the addition of signal peptide to E7(detox)/HSP70 in the DNA vaccine significantly improved the efficacy of the intramuscular method of immunization. An E7 gene with mutations in the critical Rb binding residues (termed E7 detox) was generated which failed to bind Rb, had no transforming activity, and yet maintained potent immunogenicity. GMP grade Sig-E7(detox)/HSP70 in the pNGVL4a DNA backbone has been manufactured for clinical trials with support from the NIH Rapid Access to Intervention Development program. An open label, dose escalation trial to evaluate the safety, feasibility, and preliminary evidence of immunological activity of four intramuscular injections of the E7(detox)HSP70 DNA vaccine in patients with HPV16-HNSCC is proposed. Immunologic activity will be assessed by measurement of the E7 specific T cell-mediated immune response using ELISPOT, CTL, tetramer staining assays, and intracellular cytokine staining followed by flow cytometry analysis as well as the humoral immune response via measurement of HPV16 E7 antibody titers. The dose that is found to be safe, feasible, and to develop evidence of immunologic activity will be studied in a future phase II trial.