Function of Distinct Dendritic Cell Subsets In a Rhesus Model

描述（申请人提供）：单核细胞来源的树突状细胞（DC）目前在临床试验中用作抗癌疫苗的载体。由于已经表明在不同条件下发育和成熟的DC在它们产生细胞因子和诱导Th 1、Th 2和CTL应答的能力方面显示出强烈的差异，因此DC在它们发挥抗肿瘤治疗效果的能力方面也可能不同。尽管DC的不同功能亚群在体外进行了广泛的表征，但它们诱导不同特征和大小的免疫应答的能力尚未在体内进行测试。我们建议开发一个模型系统，用于评估和优化恒河猴骨髓和浆细胞样DC功能。基于以前的结果，我们假设极化髓样DC 1，生长在GM-CSF和IL-4，并在体外产生高水平的IL-12，并优先诱导Th 1和CTL反应，将被证明是最有效的DC刺激Th 1和CTL反应在体内。然而，浆细胞样DC也显示出诱导Th 1和CTL应答，如在GM-CSF和IL-15中培养的DC。我们建议测试在不同方案和不同成熟阶段产生的DC的功效，通过不同组的细胞因子极化，以及暴露于 多种形式的抗原，以在体外和体内诱导不同类型的免疫应答。我们将首先开发产生恒河猴DC的方案，用抗原加载它们，并在体外诱导极化表型。这些细胞的表型和功能能力，包括产生的细胞因子，将被广泛表征。我们接下来将测试不同类型的DC在结内注射后在淋巴结的T细胞区域中的有效定位。最后，我们将在体内测试不同类型的DC刺激极化的CD 4 T细胞对抗原的应答和刺激CD 8 T细胞应答的能力。激发强烈Th 1型应答的免疫策略可能用于本P01中其他项目和未来研究中正在进行的临床试验。

DESCRIPTION (provided by applicant): Monocyte-derived dendritic cells (DC) are currently used in clinical trials as carders of anti-cancer vaccines. As it has been shown that DC developing and maturing in different conditions show strong differences in their abilities to produce cytokines and to induce Th1, Th2, and CTL responses, it is likely that DC will also differ in their ability to exert antitumor therapeutic effect. Despite extensive in vitro characterization of distinct functional subsets of DC, their ability to induce immune responses of different character and magnitude has not been tested in vivo. We propose to develop a model system for evaluating and optimizing myeloid and plasmacytoid DC function in rhesus macaques. Based on previous results, we hypothesize that polarized myeloid DC1, grown in GM-CSF and IL-4 and which in vitro produce high levels of IL-12 and preferentially induce Th1 and CTL responses, will prove to be the most potent DC for stimulating Th1 and CTL responses in vivo. However, plasmacytoid DC have also been shown to induce Th1 and CTL responses, as have DC cultured in GM-CSF and IL-15. We propose to test the efficacy of DC generated in different protocols and at different stages of maturation, polarized by different sets of cytokines, as well as exposed to multiple Forms of antigen, to induce different classes of immune responses in vitro and in vivo. We will first develop protocols for generating rhesus DC, loading them with antigens, and inducing polarized phenotypes in vitro. The phenotype and functional capacities of these cells, including cytokines produced, will be characterized extensively. We will next test the different types of DC for efficient localization in T cell areas of lymph nodes after intranodal injection. Finally, we will test in vivo the ability of different DC types to stimulate polarized CD4 T cell responses to antigens and to stimulate CD8 T cells responses. Immunization strategies that provoke strong Th1-type responses will potentially be used for clinical trials being performed in other projects within this P01, and in future studies.