HEAD AND NECK SQUAMOUS CELL CARCINOMA

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者的研究机构。 最近有报道称，HPV与头颈部鳞状细胞癌的一个独特子集之间存在病因学关联的强有力证据，其特征在于肿瘤细胞核中存在高危HPV DNA。 这些肿瘤绝大多数是HPV 16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，因此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癌蛋白的细胞免疫应答的治疗策略。 在临床前模型系统中，结核分枝杆菌热休克蛋白70（HSP 70）与HPV 16 E7抗原的连接被证明显著增强裸DNA疫苗的效力。 与用野生型E7 DNA接种相比，用E7/HSP 70 DNA接种小鼠使HPV 16 E7特异性CD 8 + T细胞的频率增加至少30倍，并对表达E7的肿瘤产生显著的抗肿瘤作用。 该疫苗显示出针对已建立的表达E7的鼠肿瘤的显著效力，其中主要组织相容性复合物（MHC）I类分子下调，这是一个重要的发现，因为相当大比例的晚期HNSCC表现出MHC I类分子的下调。重复DNA疫苗接种引起了不同的细胞毒性T淋巴细胞（CTL）具有更高的亲和力和改善的保护性抗肿瘤作用。 此外，在DNA疫苗中向E7（detox）/HSP 70添加信号肽显著提高了肌内免疫方法的效力。产生了在关键Rb结合残基中具有突变的E7基因（称为E7排毒），其不能结合Rb，没有转化活性，但仍保持有效的免疫原性。 pNGVL 4a DNA骨架中的GMP级Sig-E7（detox）/HSP 70已在NIH快速干预开发计划的支持下生产用于临床试验。提出了一项开放标签、剂量递增试验，以评估HPV 16-HNSCC患者四次肌内注射E7（排毒）HSP 70 DNA疫苗的安全性、可行性和免疫活性的初步证据。将通过使用ELISPOT、CTL、四聚体染色测定和细胞内细胞因子染色测量E7特异性T细胞介导的免疫应答，随后进行流式细胞术分析以及通过测量HPV 16 E7抗体滴度测量体液免疫应答来评估免疫活性。将在未来的II期试验中研究发现安全、可行并产生免疫活性证据的剂量。

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.