NKT Cells Immunotherapy: Targeting Dendritic Cells with Glycolipid Liposomes

NKT 细胞免疫疗法：用糖脂脂质体靶向树突状细胞

• 批准号: 7136054
• 负责人: Peng George Wang
• 金额: $ 17.1万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-08 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7136054
• 关键词: antigens; dendritic cells; glycolipids; immunotherapy; ligands; liposomes; oligosaccharides

DESCRIPTION (provided by applicant): A. SPECIFIC AIMS This research program combines expertise from three different laboratories at The Ohio State University and an industry partner to work on the first proof of concept for liposomal glycolipid drug delivery to dendritic cells for better harnessing the wide range of immunological functions of natural killer T cells. Conventional CD4+ and CD8+ T cells of the immune system recognize specific peptide antigens bound to major histocompatibility complex (MHC) class II or MHC class I molecules, respectively. In contrast, a specialized subpopulation of T cells called NKT cells recognize glycolipids antigens presented by the MHC class l-like molecule; CD1d. NKT cells represent a distinct population of T cells that express a conserved alpha-beta T cell receptor (TCR) and natural killer (NK) receptors. Mouse (m) Valpha14 and human (h) Valpha24 NKT cells regulate a number of critical biological conditions in vivo, including malignancy and infection, as well as autoimmune diseases, through the rapid secretion of T helper 1 (Th1) and Th2 cytokines and chemokines. A synthetic glycosphingolipid called alpha-galactosylceramide (alpha-GalCer), originally derived from a marine sponge, has been used in research as an exogenous ligand for CD1d to stimulate NKT cells. Moreover, alpha-GalCer is currently being tested in cancer patients. However, no complete objective response has been found in several clinical trials conducted by different teams in the United States, Japan and Europe. One of possible reasons might be that alpha-GalCer is too strong ligand that stuns the NKT cells to bring anergy. So far, a much more successful NKT cell immunotherapy approach is to re-induce human mature dendritic cells pulsed with alpha-GalCer ex vivo into patient to expand NKT cells. However, DCs are a small population of cells, and their isolation and pulsing with antigen can be impractical. Thus, we propose to incorporate alpha-GalCer (or other glycosphingosines) into liposomes to deliver the drug to DCs for optimal immunotherapy. Among many receptors on DCs for targeting, we choose recently discovered DC-specific intercellular adhesion molecule 3 (ICAM-3) grabbing non- integrin (DC-SIGN). Human DC-SIGN is abundantly expressed on DCs residing in lymphoid tissues and at mucosal surfaces, dermal DCs, and by specialized macrophages in placenta and lung. Several laboratories have demonstrated that targeting DC-SIGN by anti-DC-SIGN antibody afford the best strategy to deliver antigens or drug into DCs. High mannose glycans are the ligand for DC-SIGN, but recently it was discovered that DC-SIGN bind the second class of glycans: fucosyl containing oligosaccharides. Thus, this proposed research program will be the first attempt to explore the anti-tumor effect of NKT ligands by targeting the glycosphingosine drug specifically to dendritic cells with liposomes which display fucose containing oligosaccharides such as Le-a and Le-x. Four specific aims are proposed in this program: 1. Synthesis of Le-a and Le-x oligosaccharides, their tetramers and their conjugates with lipids, measurement of their binding with DC-SIGN. 2. Production of two liposomal systems. System A consists of a-GalCer with anti-DC-SIGN antibody displayed; system B consists of alpha-GalCer with fucosylated oligosaccharide displayed (e.g. Le-a and Le-x). 3. Investigation in vitro of the two liposomal systems for their targeting and cytotoxicity. 4. Investigation in vivo of the two liposomal systems for their antitumor effects in mouse models. This exploratory research will open many future possibilities on NKT activation, dendritic cell targeting, and liposomal technology. The proposed DC-targeted liposomal systems incorporated with glycolipids as NKT cell activators can be potentially used in vaccine adjuvant development and in preventing infections, autoimmune diseases and inflammatory diseases. This work will set up a novel platform to better use a wide range of possible medical benefits brought about by our recent understanding on the immunoregulatory and immunomodulatory functions of natural killer T cells.

描述（由申请人提供）：A。具体目标该研究计划结合了来自俄亥俄州州立大学三个不同实验室的专业知识和行业合作伙伴，致力于脂质体糖脂药物递送至树突状细胞的第一个概念验证，以更好地利用自然杀伤T细胞的广泛免疫功能。免疫系统的常规CD 4+和CD 8 + T细胞分别识别与主要组织相容性复合体（MHC）II类或MHC I类分子结合的特异性肽抗原。相比之下，一种称为NKT细胞的特化T细胞亚群识别由MHC I类分子（CD 1d）呈递的糖脂抗原。NKT细胞代表表达保守的α-β T细胞受体（TCR）和自然杀伤（NK）受体的不同T细胞群体。小鼠（m）Valpha 14和人（h）Valpha 24 NKT细胞通过快速分泌T辅助细胞1（Th 1）和Th 2细胞因子和趋化因子来调节体内许多关键生物学状况，包括恶性肿瘤和感染以及自身免疫性疾病。一种称为α-半乳糖神经酰胺（α-GalCer）的合成鞘糖脂，最初来源于海绵，已在研究中用作CD 1d的外源配体，以刺激NKT细胞。此外，alpha-GalCer目前正在癌症患者中进行测试。然而，在美国、日本和欧洲不同团队进行的多项临床试验中，均未发现完全客观缓解。其中一个可能的原因可能是α-GalCer是太强的配体，它使NKT细胞失去反应性。到目前为止，更成功的NKT细胞免疫治疗方法是将用α-GalCer离体脉冲的人成熟树突状细胞再诱导到患者体内以扩增NKT细胞。然而，DC是一小群细胞，并且它们的分离和用抗原脉冲可能是不切实际的。因此，我们提出将α-GalCer（或其他鞘糖醇）掺入脂质体中以将药物递送至DC以进行最佳免疫治疗。在DC上的许多受体中，我们选择最近发现的DC特异性细胞间粘附分子3（ICAM-3）抓取非整合素（DC-SIGN）。人DC-SIGN在位于淋巴组织和粘膜表面的DC、真皮DC以及胎盘和肺中的特化巨噬细胞上大量表达。一些实验室已经证明，通过抗DC-SIGN抗体靶向DC-SIGN提供了将抗原或药物递送到DC中的最佳策略。高甘露糖聚糖是DC-SIGN的配体，但最近发现DC-SIGN结合第二类聚糖：含岩藻糖基的寡糖。因此，这项研究计划将是首次尝试探索NKT配体的抗肿瘤作用，通过将鞘氨醇药物特异性靶向树突状细胞，脂质体显示含岩藻糖的寡糖，如Le-a和Le-x。该计划提出了四个具体目标：1。合成Le-a和Le-x寡糖、其四聚体及其与脂质的缀合物，测量其与DC-SIGN的结合。2.两种脂质体系统的产生。系统A由展示抗DC-SIGN抗体的α-GalCer组成;系统B由展示岩藻糖基化低聚糖的α-GalCer组成（例如Le-a和Le-x）。3.两种脂质体系统的靶向性和细胞毒性的体外研究。4.两种脂质体系统在小鼠模型中的体内抗肿瘤作用研究。这项探索性研究将为NKT激活、树突状细胞靶向和脂质体技术开辟许多未来的可能性。所提出的DC靶向脂质体系统与糖脂作为NKT细胞活化剂结合，可以潜在地用于疫苗佐剂开发和预防感染、自身免疫性疾病和炎性疾病。这项工作将建立一个新的平台，以更好地利用我们最近对自然杀伤T细胞的免疫调节和免疫调节功能的理解所带来的广泛的可能的医疗益处。