FUNCTION OF DISTINCT DC SUBSETS IN RHESUS MODEL

描述（由申请人提供）：单核细胞来源的树突状细胞（DC）目前作为抗癌疫苗的载体用于临床试验。研究表明，DC在不同条件下发育和成熟，其产生细胞因子和诱导Th1、Th2、CTL反应的能力存在较大差异，因此DC在发挥抗肿瘤治疗作用的能力也可能存在差异。尽管在体外对DC的不同功能亚群进行了广泛的表征，但它们诱导不同性质和程度的免疫反应的能力尚未在体内得到测试。我们建议建立一个评估和优化恒河猴髓细胞和浆细胞样DC功能的模型系统。基于先前的结果，我们假设在GM-CSF和IL-4中生长的极化髓系DC1，在体外产生高水平的IL-12并优先诱导Th1和CTL反应，将被证明是体内刺激Th1和CTL反应最有效的DC。然而，浆细胞样DC也被证明可以诱导Th1和CTL反应，就像在GM-CSF和IL-15中培养的DC一样。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，由不同的细胞因子组极化，以及暴露于

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.