Biology of the Eosinophilic Leukocyte

在本报告年度，我们继续探索嗜酸性粒细胞及其与呼吸道病毒病原体的相互作用。我们的新的嗜酸性粒细胞培养系统，它从未选择的小鼠骨髓前体细胞中产生大量高纯度(&gt；95%)的细胞(Dyer等人。j免疫。2008年)，促进了这一持续的努力。在最近的一份出版物中(Dyer等人我们证明了人和鼠的嗜酸性粒细胞分别是肺炎病毒病原体、呼吸道合胞病毒(RSV)和小鼠肺炎病毒(PVM)的感染靶点，并且病毒感染诱导了疾病相关的促炎介质的释放，包括几种趋化因子和细胞因子IL-6。最有趣的是，与RSV挑战小鼠肺组织的研究结果相反，在缺乏TLR信号适配器MyD88的小鼠嗜酸性粒细胞中，PVM复制加速，介质释放也随之减少。进一步研究，我们发现外源性IL-6抑制了MyD88基因缺失的嗜酸性粒细胞中的病毒复制，这表明依赖于MyD88的细胞因子介导的反馈电路在调节这一反应中发挥了作用。综上所述，我们的发现表明，嗜酸性粒细胞可以作为生产性病毒感染的靶点，因此在肺炎病毒疾病的发病和解决中可能有不同和复杂的贡献。 关于这一主题的另一项重要研究集中在接种福尔马林固定的小鼠肺炎病毒(PVM)疫苗时引发的嗜酸性粒细胞的作用，这一范式类似于Th2介导的增强型疾病对灭活RSV疫苗的反应。我们证明，接种来自PVM感染细胞的福尔马林灭活AGS(PVM AGS)的小鼠感染PVM会产生Th2扭曲超敏反应，与HRSV反应相似，包括接种PVM AGS的PVM感染小鼠的支气管肺泡灌洗液中IL-4、IL-5、IL-13和嗜酸性粒细胞水平升高，但接种未感染细胞的福尔马林灭活AGS的小鼠(对照AGS)不产生Th2扭曲超敏反应。有趣的是，尽管没有血清中和抗体，但与接种对照AGS的感染小鼠相比，接种PVM Ag的小鼠的肺部病毒滴度和体重减轻的保护作用大约降低了10倍，尽管对嗜酸性粒细胞缺乏的后续研究显示，似乎矛盾的是，嗜酸性粒细胞缺乏对PVM Ag接种的小鼠的病毒滴度或临床症状没有影响。我们正在探索嗜酸性粒细胞激活状态的性质，作为其促进体内病毒清除能力的一个关键特征(Percopo等人。免疫学杂志，2009) 我们还发表了一篇论文，探索了两种并行分离方法对嗜酸性粒细胞功能和培养活性的影响(PerCopo等人。Exp Dermatol.，2009，在印)。我们产生这些发现是对同一杂志上较早的一篇文章的回应，该文章报道了用多抗体珠试剂盒分离的阴性选择的嗜酸性粒细胞功能障碍，并在培养中经历了快速的凋亡。我们发现完全相反的结果，具体地说，在从浓缩的白细胞制剂中分离大量嗜酸性粒细胞时，多抗体嗜酸细胞分离方法比传统的抗CD-16微球具有显著的优势，最重要的是，没有观察到差异存活或过早凋亡。 另一份出版物(邱晓华等人J Biol Chem.，2009)描述了GATA因子在促进嗜酸性粒细胞衍生神经毒素(EDN)转录中的作用，也被称为RNaseA核糖核酸酶2。这项研究在AI000942-06中进行了详细讨论。 最后，我将我在嗜酸性粒细胞生物学和进化方面的专业知识贡献给了由NIAID CMB的Alfonso Gozalo博士领导的一项灵长类病理学研究，该研究结果发表了(Gozalo等人)。JAALAS 2009)。据我们所知，这是首次在非人类灵长类动物中描述推定的高嗜酸性粒细胞综合征。 在本报告所述期间，我撰写了两篇重要的评论。第一次是特邀综述，介绍了我们在嗜酸性粒细胞与呼吸道病毒病原体相互作用方面的工作(Rosenberg等人，免疫研究，2009年)，第二次，在类似的主题上，对该领域进行了更深入的同行评议(Rosenberg等人，抗病毒研究，2009年)。 最后，我在嗜酸性粒细胞生物学和炎症方面的专业知识使我有机会作为编辑委员会的成员参加《血液》(自2003年以来)、《白细胞生物学杂志》(自1996年以来)、《临床与疫苗免疫学》(自2003年以来)和《1000生物学学院》(自2006年以来)。

During this reporting year, we have continued our exploration of eosinophils and their interactions with respiratory virus pathogens. Our novel eosinophil culture system, which generates large numbers of cells at high purity (>95%) from unselected mouse bone marrow progenitors (Dyer et al. J Immunol. 2008), has facilitated this ongoing effort. In a recent publication (Dyer et al. BLOOD, 2009 in press) we demonstrated that both human and mouse eosinophils serve as targets for infection by the pneumovirus pathogens, respiratory syncytial virus (RSV) and pneumonia virus of mice (PVM), respectively, and that virus infection elicits the release of disease-related proinflammatory mediators, including several chemokines and the cytokine, IL-6. Most interesting, and in contrast to the findings reported in lung tissue of RSV-challenged mice, PVM replication is accelerated in mouse eosinophils that are devoid of the TLR-signaling adapter, MyD88, and mediator release is diminished concomittantly. Pursuing this further, we found that exogenous IL-6 suppresses virus replication in MyD88 gene-deleted eosinophils, suggesting a role for a MyD88-dependent cytokine-mediated feedback circuit in modulating this response. Taken together, our findings indicate that eosinophils can serve as targets for productive virus infection, and thus may have varied and complex contributions to the pathogenesis and resolution of pneumovirus disease. Another signinficant study on this topic focused on the role of eosinophils elicited in response to vaccination with formalin-fixed pneumonia virus of mice (PVM), a paradigm that is analogous to the Th2-mediated enhanced disease described in response to inactivated RSV vaccines. We demonstrated that PVM infection in mice vaccinated with formalin-inactivated Ags from PVM-infected cells (PVM Ags) yields Th2-skewed hypersensitivity, analogous to that observed in response to hRSV, including elevated levels of IL-4, IL-5, IL-13, and eosinophils in bronchoalveolar lavage fluid of PVM-infected mice that were vaccinated with PVM Ags, but not among mice vaccinated with formalin-inactivated Ags from uninfected cells (control Ags). Interestingly, infection in PVM Ag-vaccinated mice was associated with an approximately 10-fold reduction in lung virus titer and protection against weight loss when compared with infected mice vaccinated with control Ags, despite the absence of serum-neutralizing Abs, although followup studies with eosinophil deficient demonstrated, seemingly paradoxically, that eosinophil deficiency had no impact on virus titer or clinical symptoms in PVM Ag-vaccinated mice. We are exploring the nature of the eosinophil-activation state as a crucial feature in its ability to promote virus clearance in vivo (Percopo et al. J Immunol., 2009) We have also published a paper that explores the impact of two parallel isolation methods on eosinophil function and viability in culture (Percopo et al. Exp Dermatol., 2009, in press). We generated these findings in response to an earlier publication in this same journal that reported that negatively-selected eosinophils isolated with multi-antibody bead kits were dysfunctional and underwent rapid apoptosis in culture. We found completely contrasting results, specifically, that multi-antibody eosinophil isolation represents a substantial advantage over traditional anti-CD-16 microbeads when isolating large numbers of eosinophils from concentrated leukocyte preparations, and most important, no differential survival or premature apoptosis was observed. Another publication (Qiu et al. J Biol Chem., 2009) delineates the role of GATA factors in promoting transcription of the eosinophil-derived neurotoxin (EDN), also known as the RNase A ribonuclease, RNase 2. This study is discussed in detail in AI000942-06. Finally, I contributed my expertise in eosinophil biology and evolution to a primate pathology study headed by Dr. Alfonso Gozalo, CMB, NIAID, which resulted in a publication (Gozalo et al. JAALAS 2009). To our knowledge, this report is the first description of presumptive hypereosinophilic syndrome in a nonhuman primate. During this reporting period, I authored two significant reviews. The first was an invited review featuring our work on interactions of eosinophils with respiratory virus pathogens (Rosenberg et al., Immunol Res., 2009), and the second, on a similar topic, a more in-depth peer-reviewed consideration of the field (Rosenberg et al., Antiviral Res., 2009). Finally, my expertise in eosinophil biology and inflammation has provided me with the opportunity to participate as a member of the Editorial Boards of Blood (since 2003), Journal of Leukocyte Biology (since 1996), Clinical and Vaccine Immunology (since 2003) and Faculty of 1000 Biology (since 2006).