Structure Studies on Proteins that Modulate IL-10 Action

描述(申请人提供)：IL-10是一种多功能细胞因子，调节复杂的免疫反应。它的正常功能是保护宿主免受不受控制的炎症反应的影响。然而，IL-10也被认为是几种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受体参与并组装成具有信号活性的IL-10/IL-10R1/IL-10R2复合体来启动的。除了细胞IL-10(CLL-10)外，EB病毒(EBV)和巨细胞病毒(CMV)在其基因组中还含有病毒IL-10模拟物(ebvlL-10和cmvlL-10)，激活IL-10信号复合体，导致重叠和不同的生物学特性。在过去的资助期间，我们确定了与高亲和力IL-10R1链结合的CLL-10、cmvlL-10和ebvlL-10的晶体结构。在这项建议中，我们将使用表面等离子体共振、定点突变、核磁共振光谱、X射线结晶学和FRET方法来研究细胞和病毒IL-10受体的相互作用。这些研究将得到对细胞内IL-10同系物IL-22和IL-20的分析的补充。这项建议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如何塑造免疫反应，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.