Melanoma vaccines using MHC-associated peptides

描述(申请人提供)：理解皮肤接种免疫生物学的经典范例是，与佐剂一起运送的抗原会产生炎症刺激，进而诱导表皮朗格汉斯细胞成熟并迁移到引流淋巴结。然而，在佐剂中重复接种黑色素瘤多肽与戏剧性的慢性局部炎症有关，并且可能具有不同的生物学特性。自身免疫性和感染性疾病的慢性炎症可导致非典型淋巴区域的新淋巴组织。这一过程被称为“淋巴新生”，可导致第三淋巴器官(TLO)的功能类似于淋巴。在单次注射不完全弗氏佐剂和GM-CSF乳剂后，我们观察到人皮肤真皮中的淋巴结样聚集体(LNLA)。这些LNLA含有成熟的CD83 DC-LAMP树突状细胞、T细胞、B细胞和外周结节地址蛋白(PNAD)表达的微血管，提示高内皮微静脉。对反复接种佐剂的多肽疫苗部位的初步研究表明，淋巴新生的其他特征，但也有证据表明，聚集体中有调节细胞。我们假设：(I)重复接种黑色素瘤多肽和佐剂可能导致LNLA持续存在并在疫苗部位产生第三淋巴器官，(Ii)延长免疫可能导致二次免疫调节影响，如果其流行和时机确定，可以有针对性地阻止这些影响，以及(Iii)抗原特异性CD4和CD8T细胞在疫苗部位局部诱导，并可能通过将多肽抗原直接引入预先诱导的免疫微环境中而产生。因此，对于目前的提议，我们建议进行2个临床试验，结合免疫特性良好的多肽疫苗和从重复免疫部位获得的组织的广泛研究。目的：1.确定重复免疫(1-3次)是否能诱导皮肤淋巴结样聚集(LNLA)和第三淋巴器官(TLO)，目的2.确定延长免疫(4-6个疫苗)是否与诱导免疫部位微环境/第三淋巴器官的免疫调节过程有关，目的3.鉴定多肽疫苗免疫部位抗原反应性的CD4和CD8 T细胞的特性。这项工作的结果可能会改变我们对免疫微环境中免疫生物学的理解，并确定联合治疗以提高抗肿瘤免疫的方法。与公共健康相关：癌症疫苗有望成为一种低毒治疗方法，可能会利用免疫系统对癌症，特别是黑色素瘤的反应。黑色素瘤疫苗可以在许多或大多数患者中诱导免疫反应，但临床效果一直令人失望。目前的建议是表征与黑色素瘤疫苗诱导免疫反应相关的细胞和分子事件，目的是通过更好地了解这些事件来提高疫苗的治疗潜力。

DESCRIPTION (provided by applicant): The classic paradigm for understanding the immunobiology of cutaneous vaccination is that antigen delivered with an adjuvant creates an inflammatory stimulus, which in turn induces epidermal Langerhans cells to mature and to migrate to draining lymph nodes. However, repeat vaccination with melanoma peptides in adjuvant is associated with dramatic chronic local inflammation and may have different biology. Chronic inflammation in autoimmune and infectious diseases can lead to new lymphoid tissues in locations that are not classic lymphoid areas. This process, termed "lymphoid neogenesis," can result in tertiary lymphoid organs (TLO) that function like lymph nodes. We have observed lymph node-like aggregates (LNLA) in the dermis of human skin after a single injection of an emulsion of incomplete Freund's adjuvant plus GM-CSF. These LNLA contain mature CD83+DC-LAMP+ dendritic cells, T cells, B cells, and peripheral node addressin (PNAd) expressing microvessels suggestive of high endothelial venules. Preliminary studies in sites of repeated peptide vaccination with adjuvant show other features of lymphoid neogenesis, but there also is evidence of regulatory cells in the aggregates. We hypothesize that: (i) repeat vaccination with melanoma peptides and adjuvant may cause persistence of LNLA and creation of tertiary lymphoid organs at vaccine sites, (ii) extending immunization may result in a secondary set of immune regulatory influences, which could be blocked in a targeted manner if their prevalence and timing is defined, and (iii) antigen specific CD4+ and CD8+ T cells are induced locally at vaccine sites and may be generated by direct introduction of peptide antigens into a pre-induced immunization microenvironment. Thus, for the current proposal, we propose to perform 2 clinical trials combining immunization with a well- characterized multipeptide vaccine with extensive studies of tissue obtained from a replicate immunization site. Specific aims are: Aim 1. To determine whether repeat immunization (1-3 times) with "Adjuvant" with or without peptides induces lymph-node like aggregates (LNLA) and tertiary lymphoid organs (TLO) in skin, Aim 2. To determine whether extended immunization (4-6 vaccines) is associated with induction of immune regulatory processes in the vaccination site microenvironment /tertiary lymphoid organs, Aim 3. To characterize antigen-reactive CD4 and CD8 T cells in sites of immunization with a multipeptide vaccine. The results of this work will likely change our understanding of the immunobiology in the immunization microenvironment and identify approaches for combination therapies to improve antitumor immunity. PUBLIC HEALTH RELEVANCE: Cancer vaccines hold promise as a low toxicity treatment that may harness the immune system's response to cancer, and to melanoma in particular. Melanoma vaccines can induce immune responses in many or most patients, but the clinical impact has been disappointing. The present proposal is to characterize cellular and molecular events associated with induction of immune responses by melanoma vaccines, with the intent of improving the therapeutic potential of vaccines through a better understanding of these events.