Initiation of immune responses to SARS COV2 in the oral cavity and upper airway

摘要 严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染导致冠状病毒疾病2019 （COVID-19）是一种威胁生命的疾病，在一部分受感染个体中涉及多系统。口头和 鼻咽（NP）上皮细胞表达SARS-CoV-2受体ACE 2， 口腔/鼻咽腔（ONP）可能是COVID-19发展的一个必要步骤。免疫应答 在ONP中首先产生的蛋白质几乎肯定对病毒清除至关重要，但也可能在病毒清除中发挥核心作用。 在许多感染个体中观察到的高度炎性损伤的发展。我们使用单细胞（SC）- 从种族多样的COVID-19患者前瞻性队列中进行RNA测序，以识别不同的 NP内的纤毛上皮细胞是SARS-CoV-2感染的直接靶细胞， 这些细胞在直接感染和未感染的旁观者细胞中产生的抗病毒应答。 有趣的是，这项分析表明，死亡率的增加与抗病毒基因应答的减弱有关， NP，这表明对鼻子中病毒感染的成功先天性反应是一个关键组成部分， 成功的抗病毒反应。除了鼻子，有强有力的证据表明SARS-CoV-2可以感染 口腔上皮虽然口腔内有几个解剖部位可能与抗病毒有关， 牙龈沟是一个独特的免疫活性部位，对维持口腔免疫至关重要。 健康牙龈上皮表达SARS-CoV-2受体ACE 2以及宿主蛋白酶 TMPRSS 2是病毒进入所必需的，但与鼻病毒相比表现出重要的免疫学差异。 包括偏向IL-17相关的中性粒细胞应答。因此，我们的总体假设是， 鉴定和增强鼻和齿龈的成功的先天性和适应性细胞免疫应答 上皮将为COVID-19带来新的治疗途径。为了解决这个假设，提出 以下目标：1. SARS-CoV-2感染后粘膜表面的细胞状态分层和病毒动力学 感染和疫苗接种; 2.比较鼻和牙龈内的记忆T细胞反应， 对SARS-CoV-2的成功或致病性应答;和3.表征宿主先天的调节 免疫防御机制对限制SARS-CoV-2感染在ONP内传播至关重要 上皮细胞为了实现这些目标，我们将分析来自COVID患者的人类ONP样本， 19，从COVID-19中恢复，并使用sc-RNA-seq，流式细胞术和其他方法接种COVID-19疫苗 分子生物学技术完成后，该项目将定义保护性先天和适应性免疫 SARS-CoV-2感染患者ONP中的运作机制，提高我们对 病毒诱导的免疫在ONP，并提供洞察这些途径如何影响疾病的发病机制。

Abstract Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a life-threatening illness with multi-system involvement in a subset of infected individuals. Oral and nasopharyngeal (NP) epithelial cells express the SARS-CoV-2 receptor ACE2, and infection of the oral/nasopharyngeal cavity (ONP) is likely an obligate step in the development of COVID-19. Immune responses first generated in the ONP are almost certainly crucial for viral clearance but may also play a central role in the development of hyperinflammatory injury observed in many infected individuals. We have used single cell (sc)- RNA sequencing from a racially diverse prospective cohort of COVID-19 patients to identify distinct subsets of ciliated epithelial cells within the NP that are direct targets for SARS-CoV-2 infection and have described innate anti-viral responses generated by those cells within both directly infected as well as non-infected bystander cells. Interestingly this analysis demonstrates that increased mortality is linked to blunted anti-viral gene response in the NP, suggesting that a successful innate response to viral infection in the nose is a critical component of a successful anti-viral response. In addition to the nose, there is strong evidence that SARS-CoV-2 can infect the oral epithelium. While there are several anatomic sites within the mouth that are likely involved in anti-viral responses, the gingival sulcus is a unique immunologically active location that is crucial for maintaining oral health. The gingival epithelium expresses both the SARS-CoV-2 receptor ACE2 as well as the host protease TMPRSS2 necessary for viral entry, but exhibits important immunological differences compared to the nasal epithelium including a bias towards IL-17 associated neutrophil responses. Thus, our overall hypothesis is that identifying and enhancing successful innate and adaptive cellular immune responses of the nasal and gingival epithelium will lead to novel therapeutic avenues for COVID-19. To address this hypothesis, propose the following aims: 1. Stratify cell states and viral dynamics across mucosal surfaces following SARS-CoV-2 infection and vaccination; 2. Compare memory T cell responses within the nose and gingiva that are associated with successful or pathogenic responses to SARS-CoV-2; and 3. Characterize the regulation of host innate immune defense mechanisms that are essential to limit propagation of SARS-CoV-2 infection within ONP epithelial cells. To accomplish these aims, we will analyze human ONP samples from individuals with COVID- 19, recovered from COVID-19, and vaccinated for COVID-19 using sc-RNA-seq, flow cytometry, and other molecular biology techniques. At completion, the project will define the protective innate and adaptive immune mechanisms operating in the ONP of patients infected with SARS-CoV-2, improve our overall understanding of viral induced immunity in the ONP, and provide insight into how these pathways influence disease pathogenesis.