Processing and Presentation of Ectromelia Virus to CD4+ T Lymphocytes

项目3的动机是两个概念。首先，识别病毒来源的CD4+T淋巴细胞(TCD4+) 在MHC II类分子的背景下，多肽对宿主驱动和增强适应性是至关重要的 反应和建立免疫记忆。第二，病原体和它们之间的相互作用 自然宿主是极其复杂的实验系统，其中病毒和宿主没有 共同进化的风险错失了对这些关系的关键洞察。尽管如此，很少有关于 TCD4+对自然感染的反应。鼠痘病毒(ECTV)提供了这一点。 以高度相关的模式提供机会，具有广泛的敏感性。虽然关系密切，但 大量研究的痘苗病毒(VACV)不是小鼠的病原体，这三个实验室的初步结果都 确定了对ECTV和VACV的反应之间的许多根本差异。因此，我们预计一个 系统检测耐药和易感小鼠对ECTV和VACV的TCD4+应答 揭示与广泛相关的见解。这个高度集成的项目有四个独立但有主题的项目 相互关联的目标。目标1将定义TCD4+反应的多肽靶点，确定处理途径 负责它们的产生，并询问多肽的同一性是否决定了TCD4+表型。这项工作将 通过成像研究来补充目标2，该研究将在体内识别相关的抗原提呈细胞， 确定不同类型的抗原在体内的呈递方式，并检查TCD4+的动力学 感染后的激活。在第三个目标中，我们将评估多肽在保护性免疫中的作用 由一条非经典但普遍存在的胞质加工途径产生。最后，出版和初步 数据表明，VACV干扰L1类限制性多肽的呈递。在目标4中，我们将评估 ECTV致力于这一努力的程度。除了提供关于 TCD4+在自然感染中的作用，项目3的结果与高度互补的结果相结合 项目1和2形成了ECTV/鼠标动态的全面图景。这张照片不仅会 提供该计划的未来方向，但也洞察许多其他病毒/宿主关系。

Project 3 is motivated by two concepts. First, CD4+ T lymphocytes (TCD4+), which recognize virus-derived peptides in the context of MHC class II molecules, are vital to the host in driving and potentiating adaptive responses and establishing immunological memory. Second, the interplay between pathogens and their natural hosts is exquisitely complex and experimental systems in which the virus and host have not coevolved risk missing crucial insights into these relationships. Despite this, there have been few studies of TCD4+ responses to a natural infection. Ectromelia virus, (ECTV) the mouse poxvirus, provides this opportunity in a highly relevant model featuring a broad range of susceptibilities. Though closely related, the much studied vaccinia virus (VACV) is not a mouse pathogen and preliminary results from all three labs have identified many fundamental differences between responses to ECTV and VACV. Thus, we expect that a systematic examination of the TCD4+ response to ECTV vs. VACV in resistant and susceptible mice will reveal insights with broad relevance. This highly integrated project has four independent but thematically connected aims. Aim 1 will define the peptide targets of TCD4+ responses, identify the processing pathways responsible for their generation, and ask whether peptide identity dictates TCD4+ phenotype. This work will be complemented in Aim 2 by imaging studies which will identify the relevant antigen presenting cells in vivo, determine how different types of antigen are presented in vivo, and examine the dynamics of TCD4+ activation following infection. In the third aim we will assess the role in protective immunity of peptides generated by a nonclassical but prevalent cytosolic processing pathway. Finally, published and preliminary data indicate that VACV interferes with class ll-restricted peptide presentation. In aim 4, we will assess the degree to which ECTV is committed to this endeavor. In addition to providing valuable information about the roles of TCD4+ in a natural infection, results from Project 3 integrate with those of the highly complementary Projects 1 and 2 to form a comprehensive picture of the ECTV/mouse dynamic. This picture will not only provide future directions for the program, but also insights into many other virus/host relationships.