Laboratory of Immunoregulation and Mucosal Immunology, VIB Center for Inflammation Research, Ghent, Belgium.
Department of Internal Medicine, Ghent University, Ghent, Belgium.
Sci Rep. 2017 Jun 14;7(1):3472. doi: 10.1038/s41598-017-03042-y.
Pneumonia virus of mice (PVM) infection has been widely used as a rodent model to study the closely related human respiratory syncytial virus (hRSV). While T cells are indispensable for viral clearance, they also contribute to immunopathology. To gain more insight into mechanistic details, novel tools are needed that allow to study virus-specific T cells in C57BL/6 mice as the majority of transgenic mice are only available on this background. While PVM-specific CD8 T cell epitopes were recently described, so far no PVM-specific CD4 T cell epitopes have been identified within the C57BL/6 strain. Therefore, we set out to map H2-IA-restricted epitopes along the PVM proteome. By means of in silico prediction and subsequent functional validation, we were able to identify a MHCII-restricted CD4 T cell epitope, corresponding to amino acids 37-47 in the PVM matrix protein (M). Using this newly identified MHCII-restricted M epitope and a previously described MHCI-restricted N epitope, we generated peptide-loaded MHCII and MHCI tetramers and characterized the dynamics of virus-specific CD4 and CD8 T cell responses in vivo. The findings of this study can provide a basis for detailed investigation of T cell-mediated immune responses to PVM in a variety of genetically modified C57BL/6 mice.
鼠肺炎病毒（PVM）感染已被广泛用作研究密切相关的人类呼吸道合胞病毒（hRSV）的啮齿动物模型。虽然 T 细胞对于清除病毒是不可或缺的，但它们也会导致免疫病理学。为了更深入地了解机制细节，需要新的工具来研究 C57BL/6 小鼠中的病毒特异性 T 细胞，因为大多数转基因小鼠仅在这种背景下可用。虽然最近描述了 PVM 特异性 CD8 T 细胞表位，但迄今为止，在 C57BL/6 品系中尚未鉴定出 PVM 特异性 CD4 T 细胞表位。因此，我们着手在 PVM 蛋白组中绘制 H2-IA 限制的表位。通过计算机预测和随后的功能验证，我们能够鉴定出一个 MHCII 限制的 CD4 T 细胞表位，对应于 PVM 基质蛋白（M）中的 37-47 个氨基酸。使用这个新鉴定的 MHCII 限制的 M 表位和以前描述的 MHCI 限制的 N 表位，我们生成了负载肽的 MHCII 和 MHCI 四聚体，并在体内表征了病毒特异性 CD4 和 CD8 T 细胞反应的动力学。这项研究的结果可为在各种遗传修饰的 C57BL/6 小鼠中详细研究 PVM 特异性 T 细胞免疫反应提供基础。
