Immune Responses to Schistosome Egg Antigens

对血吸虫卵抗原的免疫反应

• 批准号: 7010718
• 负责人: Donald A Harn
• 金额: $ 42万
• 依托单位: HARVARD SCHOOL OF PUBLIC HEALTH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7010718
• 关键词: Immune; Responses; Schistosome; Egg; Antigens

DESCRIPTION (provided by applicant): This new proposal focuses on how a defined schistosome Th2 PAMP activates and matures dendritic cells to DC2s which then drive adaptive Th2 biased CD4+ T cell responses. DCs are activated when cell surface receptors ligate pathogen associated molecular patterns (PAMPs). In general, PAMPs activate APCs to produce Type-l, pro-inflammatory mediators, driving DCs to a DC1-type. DC1s present peptide to naive CD4+ T cells inducing a Th1-type response (). In contrast, little is known about the molecular nature of Th2-PAMPs or the mechanism by which they activate DCs. Lacto-N-fucopentaose III (LNFPIII) is the first Th2 PAMP described from helminth parasites. This glycan contains the Lewis X trisaccharide. When presented as a conjugate on a carrier (LNFPIII-C), LNFPIII drives Th2 responses in vivo and activates immature DCs to functional DC2s in vitro. The overall goal of this proposal is to examine activation of DCs and macrophages by LNFPIII-C compared to the Th1 PAMP LPS, to gain an understanding of the biology of recognition and activation of these cells by a schistosome Th2 PAMP. Based on preliminary studies we hypothesize that LNFPIII-C requires Toll Like Receptor 4 (TLR4) and MD2 but not the TIR adaptor protein MyD88 to to drive DCs to DC2s. We will test this by generating DCs and macrophages from mice deficient inTLR4 and/or CD14, or MyD88. We will also use HEK293 cells singly or doubly transfected with TLR2, TLR4, MD2 and CD14 or use murine macrophages that are dominant negative mutants for the TIR adaptor proteins TIRAP and MyD88. We hypothesize that the MAP kinase ERK, NF-kB and PGE2 are required for LNFPIII-C activation of DCs and that there are additional signaling molecules and mediators differentially expressed in LNFPIII/Lewis X activated DCs. We will test these aspects using inhibitors and targeted microarray analysis. We believe that the pattern of activation of DCs in vitro by LNFPIII-C/Lewis X is representative of what occurs in vivo and will test this by examining the responses of endogenous splenic DCs. The ability of LNFPIll-C to activate macrophages is fucose dependent, with no apparent role for carrier molecules other than to present multiple copies of LNFPIII. However, because schistosome Lewis X is found on glycolipids as well as glycoproteins we propose experiments to test whether the presence of a glycolipid tail alters LNFPIII/Lewis X activation of DCs. The specific aims are: 1) Does LNFPIII-C activation of macrophages and maturation of DC2s require the TLR4 receptor complex and the T1R adaptor proteins?; 2) What signaling molecules and mediators are required or utilized by LNFPIII-C in activation of macrophages and maturation of DC2s; 3) Will LNFPIII-C/Lewis X drive similar patterns of DC activation in vivo. 4) Does the presence of a lipid tail on LNFPIII/Lewis X alter DC or macrophage recognition or activation.

描述（由申请人提供）：该新提案侧重于定义血吸虫Th2 PAMP如何激活并使树突状细胞成熟为DC2s，然后驱动适应性Th2偏向CD4+ T细胞反应。当细胞表面受体连接病原体相关分子模式（PAMPs）时，DCs被激活。一般来说，PAMPs激活apc产生1型促炎介质，将dc驱动为dc1型。DC1s向初始CD4+ T细胞呈递肽，诱导th1型应答（）。相比之下，人们对Th2-PAMPs的分子性质或它们激活dc的机制知之甚少。Lacto-N-fucopentaose III （LNFPIII）是第一个从寄生虫中发现的Th2 PAMP。这种聚糖含有路易斯X三糖。当作为载体（LNFPIII- c）的缀合物呈现时，LNFPIII在体内驱动Th2反应，并在体外激活未成熟dc到功能DC2s。本研究的总体目标是比较LNFPIII-C和Th1 PAMP LPS对DCs和巨噬细胞的激活，以了解血吸虫Th2 PAMP对这些细胞的识别和激活的生物学过程。根据初步研究，我们假设LNFPIII-C需要Toll样受体4 （TLR4）和MD2，而不需要TIR适配器蛋白MyD88来驱动dc到DC2s。我们将通过从缺乏inTLR4和/或CD14或MyD88的小鼠中产生DCs和巨噬细胞来测试这一点。我们还将使用单或双转染TLR2、TLR4、MD2和CD14的HEK293细胞，或使用TIR接头蛋白TIRAP和MyD88的显性阴性突变的小鼠巨噬细胞。我们假设MAP激酶ERK， NF-kB和PGE2是LNFPIII- c激活dc所必需的，并且在LNFPIII/Lewis X激活的dc中存在其他差异表达的信号分子和介质。我们将使用抑制剂和靶向微阵列分析来测试这些方面。我们认为LNFPIII-C/Lewis X在体外激活dc的模式代表了体内发生的情况，并将通过检查内源性脾dc的反应来验证这一点。LNFPIll-C激活巨噬细胞的能力是病灶依赖性的，除了呈现多个LNFPIII拷贝外，载体分子没有明显的作用。然而，由于血吸虫Lewis X存在于糖脂和糖蛋白上，我们提出了实验来测试糖脂尾的存在是否会改变LNFPIII/Lewis X对dc的激活。具体目的是：1)LNFPIII-C激活巨噬细胞和DC2s成熟是否需要TLR4受体复合物和T1R接头蛋白；2) LNFPIII-C在巨噬细胞活化和DC2s成熟过程中需要或利用哪些信号分子和介质；3) LNFPIII-C/Lewis X在体内是否会驱动类似的DC激活模式？4) LNFPIII/Lewis X上脂质尾的存在是否会改变DC或巨噬细胞的识别或激活？