COVID19: Respiratory SARS-CoV-2 seroprevalence and the association of humoral immune responses with clinical outcomes in veterans and employees in the Cleveland VA Medical Center

SARS-CoV-2的全球大流行对卫生保健工作者和研究人员提出了迫切的要求。 在4月3日至5月1日期间，全球新冠肺炎病例几乎增加了两倍，从大约100万例增加到300万例以上 百万美元。随着秋季SARS-CoV-2病毒再次出现的可能性，快速特异性抗体检测是 必不可少的。本申请旨在研究退伍军人对SARS-CoV-2的体液免疫应答 以及克利夫兰退伍军人医疗中心的员工。该提案有三个目标。目标1)快速发展， 高通量检测SARS-CoV-2蛋白总抗体和功能抗体的研究 被感染的人。在目标1中，我们将建立一种基于磁珠的检测抗体(Ab)的方法 在一个血清样本中对多达50个不同的SARS-CoV-2表位的反应。这项化验也将能够 检测干扰SARS病毒S蛋白受体结合域(RBD)结合的抗体 CoV-2与其受体ACE2结合。阻断肺上皮细胞RBD与ACE2结合的抗体 细胞将阻止病毒进入，并可能中和。目的2)确定强健的体液免疫和 更高的中和抗体效价保护退伍军人保健人员免受临床COVID19的影响 SAR2-CoV-2特异性抗体低或不存在的同事。在目标2中，我们将使用快速抗体测试来筛选 克利夫兰退伍军人医疗保健员工感染COVID19的高危人群(急救人员，急诊 科室工作人员、重症监护室工作人员、COVID19病房工作人员)。我们会要求那些人的血清样本 COVID19抗体阳性者，用于更深入地检测SARS-CoV-2抗体应答。我们将研究 一般抗体滴度、中和抗体滴度和抗体亚型。如果秋季COVID19病毒卷土重来， 我们将确定那些体液反应强烈的医疗保健员工是否得到了更好的保护 比那些抗体反应弱或没有抗体反应的员工更容易感染。目标3)检查与 COVID19诱导的淋巴细胞减少症，具有产生体液免疫反应的能力。年纪较大，SARS- CoV-1和SARS-COV-2感染都与白细胞减少或淋巴细胞减少有关。在……里面 目的研究淋巴细胞减少对柯萨奇病毒19的体液抗体反应的影响。 我们预计，那些有严重淋巴细胞减少的人的淋巴中几乎没有T滤泡辅助细胞 这将导致较差的抗体亲和力成熟、同型转换和B细胞记忆发育。在……里面 总之，本项目结果将提供一种能够快速检测SARS-CoV-2特异性血清的方法 中和抗体，可用于筛查退伍军人管理局医护人员是否接触SARS-CoV-2。我们会 高危医护人员感染猪瘟后体液抗体反应的调查 COVID19，并试图确定如果出现新冠病毒卷土重来，什么构成预防再次感染 COVID19在秋季。最后，我们将了解B细胞亲和力成熟、同型转换 并产生B细胞记忆和中和抗体效价，并确定淋巴细胞减少如何在 柯萨奇病毒19的体液免疫功能障碍。这一知识将有助于开发更好的治疗方法 以及未来的疫苗。

The global pandemic of SARS-CoV-2 is placing urgent demands on health care workers and researchers. Between April 3rd and May 1st global cases of COVID19 nearly tripled from approximately 1 million to over 3 million. With the possibility of a reemergence of SARS-CoV-2 in the fall, rapid specific antibody assays are essential. This application proposes to investigate the humoral immune responses to SARS-CoV-2 in veterans and employees at the Cleveland VA Medical Center. The proposal has three aims. Aim 1) To develop rapid, high throughput assays to measure total and functional antibodies to SARS-CoV-2 proteins in COVID19 infected individuals. In aim 1, we will establish a magnet bead-based assay that can detect antibody (Ab) responses to up to 50 different epitopes of SARS-CoV-2 in one serum sample. This assay will also be able to detect Abs that interfere with the binding of the receptor binding domain (RBD) of the spike protein of SARS- CoV-2 to its receptor, ACE2. Antibodies that can block binding between the RBD and ACE2 on lung epithelial cells will prevent viral entry and will likely be neutralizing. Aim 2) To determine if robust humoral immunity and higher neutralizing Ab titers protect VA health care employees from clinical COVID19 compared to their colleagues with low or no SAR2-CoV-2 specific antibodies. In aim 2 we will use a rapid antibody test to screen Cleveland VA health care employees at high-risk for infection with COVID19 (first responders, emergency department staff, intensive care unit staff, COVID19 ward staff). We will ask for a serum sample from those that are Ab positive for COVID19 to examine the SARS-CoV-2 Ab response in more depth. We will examine general Ab titers, neutralizing Ab titers, and antibody isotypes. If there is a resurgence of COVID19 in the fall, we will determine if those health care employees with a robust humoral response are better protected from re- infection than those employees who had a weak or no Ab response. Aim 3) To examine the association of COVID19-induced lymphopenia with the ability to generate a humoral immune response. Older age, SARS- CoV-1 and SARS-COV-2 infection are all associated with a decrease of white blood cells or lymphopenia. In aim 3 we will examine the effect of lymphopenia on the development of the humoral Ab response to COVID19. We expect that those individuals with severe lymphopenia will have few T follicular helper cells in their lymph nodes and this will lead to poor Ab affinity maturation, isotype switching, and B cell memory development. In summary, results from this project will provide a rapid SARS-CoV-2 specific serum assay able to detect neutralizing Ab that can be used to screen VA healthcare workers for exposure to SARS-CoV-2. We will investigate the humoral antibody responses of high-risk health care employees that were infected with COVID19 and try to determine what constitutes protection from re-infection if there is a resurgence of COVID19 in the fall. Lastly, we will gain an understanding of the B cell affinity maturation, isotype switching and generation of B cell memory and neutralizing Ab titers and determine how lymphopenia may play a role in the dysfunction of humoral immunity to COVID19. This knowledge will aid in development of better treatment and future vaccines.