MULTI-EPITOPE MELANOMA VACCINES FOR CD4 AND CD8 T-CELLS

描述（由申请人提供）：人类黑色素瘤反应性T细胞识别的肽抗原可以纳入疫苗中，以诱导针对黑色素瘤的免疫反应。该领域的大多数工作仅限于使用单一抗原或少数抗原，仅针对CD8+ T细胞。这些疫苗诱导CD8+ T细胞反应，但通常是低强度的，客观肿瘤消退并不常见。为了改进疫苗策略，可能有助于增加靶向抗原的数量，增加应答的强度，同时靶向CD4和CD8 T细胞，并通过诱导记忆来增加免疫应答的持久性。CD4反应似乎对免疫记忆和树突状细胞激活至关重要。非特异性刺激CD4 T细胞可在接种部位诱导辅助性T细胞应答；然而，维持CD4 t细胞在肿瘤部位的帮助可能需要对黑色素瘤抗原进行更特异性的刺激。现在已经确定了辅助性T细胞的多个肽表位，可以评估它们的免疫原性，并确定它们是否会增加CD8反应的强度和持久性。针对CD4和CD8 T细胞接种多肽疫苗的免疫效果将在临床试验E1602中进行评估。本试验中使用的肽抗原包括(i)由i类MHC分子HLA-A1、A2或A3 （12MP）限制的12种黑色素瘤肽的混合物，（ii）由HLA-DR分子（6MHP）限制的6种黑色素瘤辅助肽的混合物，以及（iii）由HLA-DR分子（tet）限制的改性破伤风肽。晚期黑色素瘤患者将随机接种4种疫苗策略中的一种：(a)仅12MP， (b) 12MP + tet, (c) 12MP + 6MHP, (d)仅6MHP。目前的应用是用于T细胞对这些多肽疫苗反应的免疫学研究，以及运输成本和疫苗佐剂成本。用于免疫监测的血液和组织将在匹兹堡大学免疫监测和细胞产品实验室（IMCPL）集中运输、准备和冷冻保存，该实验室是东部肿瘤合作小组（ECOG）的核心实验室，具有冷冻保存的经验和认证。细胞免疫监测试验将由弗吉尼亚大学人类免疫治疗中心实验室进行。细胞因子检测将在匹兹堡IMCPL进行。具体目的是：1)估计在含有多个I类mhc限制性肽的疫苗中添加辅助肽是否能增强t细胞对I类限制性肽的反应；2)研究疫苗诱导的CD8+ T细胞的效应型和记忆型表型；3)测定辅助性T细胞对破伤风肽和6种受多种HLA-DR分子限制的黑色素瘤辅助性肽的反应；4}获取IV期黑色素瘤患者每三个月加强接种一次疫苗是否可以维持对肽疫苗的免疫反应的初步数据；5)在本研究的四组中，获得12肽疫苗的细胞免疫应答是否与临床结果相关的初步数据。

DESCRIPTION (provided by applicant): Peptide antigens recognized by human melanoma-reactive T cells can be incorporated in vaccines to induce immune responses against melanoma. Most work in this area has been limited to the use of single antigens, or few antigens, targeting only CD8+ T cells. These vaccines induce CD8+ T cell responses, but often of low magnitude, and objective tumor regressions have been uncommon. To improve vaccine strategies, it may help to increase the number of antigens targeted, to increase the magnitude of responses, to target both CD4 and CD8 T cells, and to increase persistence of the immune response through induction of memory. CD4 responses appear to be critical for immunologic memory, and for dendritic cell activation. Nonspecific stimulation of CD4 T cells may induce helper T cell responses at the site of vaccination; however, maintaining CD4 T-cell help at sites of tumor may require that they are stimulated more specifically toward melanoma antigens. Now that multiple peptide epitopes for helper T cells have been defined, it is feasible to assess their immunogenicity, and to determine whether they increase the magnitude and persistence of CD8 responses. The immunologic effects of vaccination with a multipeptide vaccine targeting CD4 and CD8 T cells will be evaluated in the clinical trial E1602. The peptide antigens used in this trial include (i) a cocktail of 12 melanoma peptides restricted by Class I MHC molecules HLA-A1, A2, or A3 (12MP), (ii) a cocktail of 6 melanoma helper peptides restricted by HLA-DR molecules (6MHP), and (iii) a modified tetanus peptide, restricted by HLA-DR molecules (tet). Patients with advanced melanoma will be randomized to one of 4 vaccine strategies: (a) 12MP only, (b) 12MP + tet, (c) 12MP + 6 MHP, and (d) 6MHP only. The current application is for immunologic studies of T cell responses to these multipeptide vaccines, as well as for shipping costs and for costs of vaccine adjuvant. Blood and tissues for immune monitoring will be shipped, prepared, and cryopreserved centrally at the Immune Monitoring and Cellular Products Laboratory (IMCPL) at the University of Pittsburgh, which is the Core Laboratory for the Eastern Cooperative Oncology Group (ECOG) and has experience and certification in cryopreservation. The cellular immune monitoring assays will be performed by the Human Immune Therapy Center Laboratory at the University of Virginia. Cytokine assays will be done at the Pittsburgh IMCPL. Specific aims are: 1) To estimate whether addition of helper peptides to a vaccine containing multiple Class I MHC-restricted peptides augments T-cell responses to the Class I restricted peptides; 2) To characterize the phenotype of vaccine-induced CD8+ T cells for effector and memory phenotypes; 3) To determine the helper T cell response to tetanus peptide and to each of 6 melanoma helper peptides, restricted by multiple HLA-DR molecules; 4} To obtain preliminary data on whether booster vaccination every three months may maintain immune responses to a peptide vaccine, in patients with stage IV melanoma; and 5) To obtain preliminary data on whether cellular immune responses to a 12-peptide vaccine may correlate with clinical outcome, among the four arms of this study.