Structure Studies on Proteins that Modulate IL-10 Action

描述（由申请人提供）：IL-10是一种调节复杂免疫反应的多功能细胞因子。它的正常功能是保护宿主免受不受控制的炎症反应。然而，IL-10也被认为是一些b细胞恶性肿瘤的自分泌生长因子，并刺激b细胞介导的自身免疫性疾病。IL-10的正常和病理功能是通过IL-10受体结合并组装成信号通路IL-10/IL-10R1/IL-10R2复合物而启动的。除了细胞IL-10 （clL-10）外，eb病毒（EBV）和巨细胞病毒（CMV）的基因组中还含有病毒IL-10模拟物（ebvlL-10和cmvlL-10），这些模拟物可以激活IL-10信号复合物，从而导致重叠和不同的生物学特性。在过去的资助期内，我们确定了与高亲和IL-10R1链结合的clL-10、cmvlL-10和ebvlL-10的晶体结构。在这个提议中，我们将使用表面等离子体共振，定点诱变，核磁共振波谱，x射线晶体学和FRET方法来研究细胞和病毒IL-10受体的相互作用。这些研究将通过分析IL-10的细胞同源物IL- 22和IL-20来补充。本提案的长期目标是推导出IL-10家族信号的定量结构/计算模型，该模型可能解释细胞和病毒IL-10如何形成免疫反应，并允许合理设计细胞因子疗法。

DESCRIPTION (provided by applicant): IL-10 is a multifunctional cytokine that regulates complex immune responses. Its normal function is to protect the host from uncontrolled inflammatory responses. However, IL-10 has also been implicated as an autocrine growth factor in several B-cell malignancies and stimulates B-cell mediated autoimmune disease. The normal and pathological functions of IL-10 are initiated by IL-10 receptor engagement and assembly into a signaling competent IL-10/IL-10R1/IL-10R2 complex. In addition to cellular IL-10 (clL-10), Epstein Barr virus (EBV) and cytomegalovirus (CMV) harbor viral IL-10 mimics (ebvlL-10 and cmvlL-10) in their genomes that activate the IL-10 signaling complex, resulting in overlapping and distinct biological properties. In the past funding period, we determined crystal structures of clL-10, cmvlL-10, and ebvlL-10 bound to the high affinity IL-10R1 chain. In this proposal we will use surface plasmon resonance, site-directed mutagenesis, NMR spectroscopy, X-ray crystallography, and FRET methods to study cellular and viral IL-10 receptor interactions. These studies will be complemented by the analysis of the cellular IL-10 homologs IL- 22 and IL-20. The long term goal of this proposal is to derive a quantitative structural/computational model of IL-10 family signaling that might explain how cellular and viral IL-10s shape immune responses and allow the rational design of cytokine therapeutics.