Integrating innate and adaptive immunity in cancer therapy

描述（由申请方提供）：持续向肿瘤微环境递送白细胞介素-12和GM-CSF可诱导预先存在的CD 8 + T效应细胞/记忆细胞快速活化，促进CD 4 + CD 25 + Foxp 3 + T抑制细胞的消除，并导致肿瘤引流淋巴结（TDLN）中继发性CD 8 + T效应细胞应答的引发。然而，肿瘤免疫抑制的逆转是短暂的，效应子激活之后是T抑制细胞的急剧反弹和T效应子静止的恢复。再刺激导致调节反弹的加剧，并最终导致治疗功效的丧失。最近的研究表明，CD 8 + T效应细胞引发和T抑制细胞反弹都是由治疗后招募到TDLN的相同髓样树突状细胞（DC）群体介导的。更重要的是，IFN？对于初始免疫原性和随后的致耐受性DC（tDC）表型的发展都是必需的。在本申请中将检验的广泛假设是IFN？DC中驱动的免疫原性和致耐受性途径可以解偶联，并且致耐受性途径的选择性抑制将中和稳态T抑制细胞反弹，导致持久的肿瘤消退。为此，目的1研究旨在描述鲜为人知的机制控制干扰素？驱动免疫原性DC（iDC）分化为tDC。更具体地说，阐明了所选干扰素调节因子（IRF）在iDC和tDC表型分化中的特定作用，以鉴定可靶向选择性阻断tDC发育和持久性的潜在检查点。在目标2中，测试了两种不同的策略，旨在通过使用独特的体内大分子递送技术来废除反调节。首先，通过siRNA/金纳米棒复合物和持续释放细胞因子/小分子药物制剂靶向治疗后tDC分化和活性的潜在调节剂，包括IRF-8、SOCS-1、IDO-1/2、GCN-2和MyD 88以及在Aim 1中鉴定的其他候选物，以阻断tDC功能。第二，基于最近的发现，证明T-抑制细胞表型具有相当大的可塑性，上述技术被用于通过Foxp 3沉默和TH 1/TH 17促进细胞因子的递送来重新编程反弹的T-抑制细胞。在目标3中，在两个临床相关肿瘤模型中研究了上述方法的长期治愈潜力。首先，利用手术转移模型来确定局部消除T抑制细胞反弹是否会导致增强的播散性疾病的根除。在第二个模型中，在晚期原发性肿瘤模型中评估慢性免疫疗法在不可切除疾病的长期管理中的效用。阐明治疗诱导的稳态反调节的分子基础和鉴定可以靶向中和T抑制剂反弹的潜在调节检查点代表了一种新的范例，如果成功，可以显著提高基于免疫的疗法的临床疗效。 公共卫生相关性：该建议将定义体内平衡调节反弹的分子机制，该反弹使治疗诱导的抗肿瘤细胞毒性细胞活性短路。描述治疗本身如何导致调节性反反应的动员，预计将揭示可用于废除调节性反弹的检查点。为此，将siRNA、重组蛋白和小分子药物的新型控释制剂与治疗结合使用，以靶向预期的检查点并重新编程调节细胞，以实现持久的肿瘤消退。

DESCRIPTION (provided by applicant): Sustained delivery of Interleukin-12 and GM-CSF to the tumor microenvironment induces rapid activation of pre-existing CD8+ Teffector/memory cells, promotes elimination of CD4+ CD25+ Foxp3+ T-suppressor cells and results in the priming of a secondary CD8+ T-effector response in the tumor-draining lymph nodes (TDLN). However, reversal of tumor immune suppression is transient and effector activation is followed by a dramatic rebound of T-suppressor cells and return of T-effector quiescence. Re-stimulation results in the intensification of the regulatory rebound and ultimately, in the loss of therapeutic efficacy. Recent work demonstrated that both CD8+ T-effector cell priming and T-suppressor cell rebound were mediated by the same myeloid Dendritic cell (DC) population that was recruited to the TDLN following treatment. More importantly, IFN? was required for the development of both the initial immunogenic and the subsequent tolerogenic DC (tDC) phenotype. The broad hypothesis that will be tested in this application is that IFN?-driven immunogenic and tolerogenic pathways in DC can be uncoupled and that selective inhibition of the tolerogenic pathway will neutralize the homeostatic T-suppressor cell rebound, resulting in durable tumor regression. To this end, Aim 1 studies are designed to delineate the little-known mechanisms controlling the IFN?-driven differentiation of immunogenic DC (iDC) to tDC. More specifically, the specific roles of selected interferon regulatory factors (IRFs) in the differentiation of iDC and tDC phenotypes are elucidated to identify potential checkpoints that can be targeted for selective blocking of tDC development and persistence. In Aim 2, two different strategies aimed at abrogating counter-regulation via the use of unique in vivo macromolecule delivery technologies are tested. First, potential regulators of post-therapy tDC differentiation and activity, including IRF-8, SOCS-1, IDO-1/2, GCN-2 and MyD88 as well as additional candidates that are identified in Aim 1, are targeted via siRNA/gold nanorod complexes and sustained-release cytokine/small molecule drug formulations to block tDC function. Second, based on recent findings demonstrating considerable plasticity in T-suppressor cell phenotype, the above technologies are utilized to re-program rebounding T-suppressor cells via Foxp3 silencing and delivery of TH1/TH17-promoting cytokines. In Aim 3, the long-term curative potential of the above approach is investigated in two clinically-relevant tumor models. First, a surgical metastasis model is utilized to determine whether local abrogation of the T-suppressor cell rebound will result in enhanced eradication of disseminated disease. In the second model, the utility of chronic immune therapy in long-term management of non- resectable disease is evaluated in an advanced primary tumor model. Elucidation of the molecular basis of treatment-induced homeostatic counter-regulation and identification of potential regulatory checkpoints that can be targeted for neutralization of the T-suppressor rebound represents a new paradigm, which if successful, can significantly improve clinical efficacy of immune-based therapies. PUBLIC HEALTH RELEVANCE: This proposal will define the molecular mechanisms underlying the homeostatic regulatory rebound that short-circuits therapy-induced antitumor cytotoxic cell activity. Delineation of how treatment itself leads to the mobilization of a regulatory counter-response is expected to reveal checkpoints that can be targeted for abrogation of the regulatory rebound. To this end, novel controlled-release formulations of siRNA, recombinant proteins and small molecule drugs are utilized in conjunction with therapy to target anticipated checkpoints and reprogram regulatory cells to achieve durable tumor regression.