Genetically humanized mice for modeling human Fc-receptor interaction during influenza infection

各种IgG的结晶片段（Fc）区之间相互作用的重要性 在建立广泛的免疫应答系统中， 人们越来越认识到对流感病毒的免疫力。然而， 在小鼠中对这些途径的研究部分地受到数量上的主要物种差异的限制， Fcγ R的结构和表达模式，特别是聚集在 1号染色体。类似地，虽然小鼠和人IgG基因座都编码四个IgG基因座，但它们都编码一个IgG基因座。 恒定区基因，从而产生四种IgG同种型，物种之间的分歧， 使得难以将小鼠直系同源物分配给人IgG恒定区基因。这些物种 这些差异也限制了小鼠作为评价试剂的临床前工具的使用 如疫苗和人源化单克隆抗体（mAb）。为了解决这个问题，我们 产生小鼠，其中编码小鼠IgG受体的三个基因座，Fc受体II/III/IV，Fc受体1a， 和FcRn（IgG转运蛋白）通过同线置换被人源化。人源化小鼠， FCGR和仅表达三种低亲和力FCGR激活之一的衍生系 受体基因，FCGR 2A，FCGR 2C或FCGR 3A，将用于评估这些基因的作用。 受体在抗体介导的抗流感保护中的作用。人Fc的贡献 理想地，在动物中研究受体，其中IgG同种型响应于 病毒具有人Fc区，确保了Fc-FC受体相互作用模拟在 人类我们通过人源化~200 kb小鼠IgH恒定区解决了这一限制， 以及κ轻链的恒定区。作为小鼠的胚胎干细胞 人源化的FCGR基因用于该基因组工程，所产生的小鼠将 不仅产生人IgG同种型，而且这些同种型将与人效应子相互作用， 这些动物将提供用于评估FC受体对效应细胞群体的影响的模型。 人单克隆抗体的有效性以及用于定义Fc-Fc β R途径， 在病毒暴露后调节疾病的发病机理和/或改善免疫力， 接种疫苗的动物

The importance of interactions between the fragment of crystallization (Fc) region of various IgG isoforms and the array of FcγRs expressed by effector immune cells in establishment of broad immunity to influenza viruses is increasingly recognized. However, the translational value of studies of these pathways in mice is limited in part by major species differences in the number, structure and expression pattern of the FcγRs, particularly the low affinity receptors clustered on chromosome 1. Similarly, although both the mouse and the human IgG locus encode four IgG constant region genes and thus produce four IgG isotypes, divergence between the species has made it difficult to assign mouse orthologs to human IgG constant region genes. These species differences have also limited the use of the mouse as a preclinical tool for evaluating reagents such as vaccines and humanized monoclonal antibodies (mAbs).To address this, we have generated mice in which the three loci encoding mouse IgG receptors, FcɣRII/III/IV, FcɣR1a, and FcRn (the IgG transporter), are humanized by syntenic replacement. Mice humanized for the FCɣRs and derived lines expressing only one of the three low affinity FCGR activating receptor genes, FCGR2A, FCGR2C or FCGR3A, will be used to evaluate the role of these receptors in antibody-mediated protection against influenza. The contribution of human Fc receptors would ideally be studied in animals in which the IgG isotypes produced in response to virus have human Fc regions, ensuring that the Fc-FCɣR interactions mimic those observed in humans. We address this limitation by humanization of the ~200 kb mouse IgH constant region, as well as the constant region for the kappa light chains. As embryonic stem cells from mice humanized for the FCGR genes are used for this genome engineering, the mice generated will not only produce human IgG isoforms, but these isoforms will interact with human effector FCɣRs on effector cell populations.These animals will provide a model for evaluation of the effectiveness of human mAbs as well as for defining Fc-FcɣR pathways whose engagement modulates the pathogenesis of disease after viral exposure and/or improves immunity in vaccinated animals.