Immune tolerance in the therapy of rheumatoid arthritis

描述(申请人提供)：关于类风湿性关节炎(RA)同时进行的临床和机制研究，几乎没有发表过关于诱导和维持免疫耐受的数据。了解诱导耐受的机制至关重要，因为一旦目前使用的治疗方法控制了最初的症状免疫激活，这种方法可能在维持疾病控制方面有效。我们最近结束了一项由美国国立卫生研究院赞助的安慰剂对照试验II期试验，该试验是关于类风湿关节炎患者对dna JP1的粘膜耐受性。Dna JP1是一种热休克蛋白衍生的多肽，我们先前发现它是RA中T细胞介导的炎症的贡献者。Dna JP1治疗导致了可检测的临床疗效，这与在体外对dna JP1反应的T细胞产生的促炎细胞因子TNFa显著减少有关。产生假说的初步研究表明，表位特异性治疗影响T细胞谱系承诺，导致从促炎(TH-1和TH-17)到调节功能的变化。这在接受羟基氯喹(HCQ)预治疗的患者中尤为明显。这些患者对dna JP1治疗有较好的临床反应。HCQ预处理可诱导一种新型调节性T细胞(Treg)，它的存在是诱导耐受所必需的。因此，这项研究的假设是：i)表位特异性治疗直接影响从TH-1/TH-17促炎效应T细胞(TEF)到Treg/耐受细胞的梯度内T细胞谱系的相对表达和功能；ii)HCQ治疗诱导APC的变化，并先导产生一种新型的调节性T细胞，通过PD-1的表达来识别；iii)治疗的效果最初是多肽特异性的，随后影响天然免疫和获得性免疫。其目的是：i)证明治疗诱导各种类型的具有调节功能的T细胞的出现：a)作为效应细胞的抑制者，从而有利于免疫偏离；b)直接裂解抗原提呈细胞(APC)，同时在其HLA上呈递dna JP1并表达适当的配体(即表达PD-1配体以结合PD-1 Treg)；ii)表征治疗诱导的TEF从TH-1/TH-17到更耐受表型的免疫偏离的性质和实体；Iii)表征HCQ在耐受机制中的“佐剂”作用，特别是HCQ诱导的APC表型和功能的变化。具体目标1：鉴定基于PD-1共表达的Treg亚群，鉴定其与dna JP1免疫耐受相关的功能，并评价其对Tef和APC的抑制/调节活性。具体目的2：研究治疗诱导的免疫偏离的本质和机制，使其从促炎的TH-1/TH-17变为耐受状态。具体目标3：研究治疗诱导的APC功能的变化，特别关注HCQ在促进具有调节/抑制潜力的T细胞诱导和结合T细胞的膜表型表达方面可能具有的“辅助”作用。我们的计划正在开发一种新的方法，直接解决耐受原作为当前使用的生物制品的补充的需求。这里提出的研究计划依赖于“床边背靠背”的反向转换路线，是该项目的基本部分，因为它将从NIH资助的第二阶段试验中获得的独特样本集合中剖析和定义耐受机制。这些研究有可能提供有关人类免疫耐受的免疫学方面的有价值的信息，还将有助于将基本的免疫学概念转化为新的工具，用于设计更好的试验和预测治疗效果，以优化患者的护理方案。

DESCRIPTION (provided by applicant): There are few published data concerning the induction and maintenance of immune tolerance based on concurrent clinical and mechanistic studies in rheumatoid arthritis (RA). It is of critical importance to understand the mechanisms of the induction of tolerance because the approach may be effective in maintaining disease control once the initial, symptomatic immune activation has been controlled by currently used therapies. We have recently concluded a NIH-sponsored placebo-controlled pilot phase II trial of mucosal tolerization to dnaJP1 in RA. dnaJP1 is a heat shock protein-derived peptide we previously identified as a contributor of T cell-mediated inflammation in RA. dnaJP1 treatment led to detectable clinical efficacy, which correlated with a significant reduction in the production of pro-inflammatory cytokine TNFa by T cells in response to dnaJP1 in vitro. Hypothesis-generating preliminary studies suggest that epitope-specific therapy affects T cell lineage commitment, resulting in a change from a pro-inflammatory (TH-1 and TH-17) to regulatory function. This is particularly evident in patients pre-treated with hydroxychloroquine (HCQ). These patients had a better clinical response to the dnaJP1 treatment. Pre-treatment with HCQ may induce a novel type of regulatory T cells (Treg), whose presence is necessary for the induction of tolerance. Therefore the hypotheses for this study are: i) epitope-specific therapy has a direct effect on the relative representation and function of T cell lineages within the gradient comprised from TH-1/TH-17 pro-inflammatory effector T cells (Teff) to Treg/ tolerogenic cells; ii) changes in the APC are induced by treatment with HCQ and are prodromic to the generation of a novel type of regulatory T cells, which is identified by the expression of PD-1; iii) The effects of therapy are initially peptide-specific and subsequently affect both innate and adaptive immunity. The objectives are: i) To demonstrate that therapy induces the emergence of various types of T cells with regulatory function that: a) act as suppressors for effector cells, thus favoring an immune deviation; b) can directly lyse antigen presenting cells (APC) which at the same time present dnaJP1 on their HLA and express the appropriate ligands (i.e. express PD-1 ligands to bind PD-1 Treg); ii) To characterize the nature and entity of the therapy-induced immune deviation in Teff from TH-1/TH-17 to a more tolerogenic phenotype; iii) To characterize the "adjuvant" role that HCQ has on the mechanism of tolerization, with a specific focus on HCQ-induced changes in APC phenotype and function. Specific Aim 1: To identify sub-populations of Treg based on co-expression of PD-1, characterize their function in relationship to immune tolerization to dnaJP1, and evaluate their suppressor/regulatory activity on Teff as well as on APC. Specific Aim 2: To characterize the nature and mechanisms of the treatment-induced immune deviation of Teff from pro- inflammatory TH-1/TH-17 to a tolerogenic status. Specific Aim 3: To study treatment-induced changes in APC function, with a specific focus on the "adjuvant" role that HCQ may have in facilitating the expression of a membrane phenotype capable of inducing and engaging T cell with a regulatory/suppressor potential. Our program is developing a novel approach that directly addresses the need of a tolerogen as a complement to currently used biologics. The research plan proposed here relies on a "bedside back to bench" reverse translational itinerary and is a fundamental part of the project, as it will dissect and define the mechanisms of tolerance from a unique collection of samples already obtained from a NIH-funded Phase II trial. These studies have the potential to provide valuable information regarding the immunology of human immune tolerance and will also help translate basic immunology concepts into novel tools for designing better trials and predicting treatment efficacy to optimize a patient's care regimen.