Project description:Single cell RNA sequencing analysis was performed on bronchoalveolar lavage samples obtained from Rhesus macaques infected intranasally/intratracheally with SARS-CoV-2 after vaccination with mRNA-1273 vaccine
Project description:The COVID-19 pandemic has led to extensive morbidity and mortality throughout the world. Clinical features that drive SARS-CoV-2 pathogenesis in humans include inflammation and thrombosis, but the mechanistic details that underlie these processes remain to be determined. In this study, we demonstrate endothelial disruption and vascular thrombosis in histopathologic sections of lungs from both humans and rhesus macaques infected with SARS-CoV-2. To define key molecular and cellular pathways associated with SARS-CoV-2 pathogenesis, we performed transcriptomic analyses of bronchoalveolar lavage (BAL) samples and peripheral blood, and proteomics analyses of serum from infected rhesus macaques. We observed upregulation of macrophage signatures, complement cascade pathways, platelet activation, and markers of thrombosis in BAL and peripheral blood as well as extensive macrophage infiltrates in lung. These observations coincided with robust induction of interferon and proinflammatory markers, including C-reactive protein, MX1, IL-6, IL-1, IL-8, TNFa and NF-κB as well as downstream signaling pathways. These findings suggest a model in which critical interactions between inflammatory and thrombosis pathways lead to SARS-CoV-2 induced vascular disease. Our findings also suggest potential novel therapeutic targets for COVID-19 disease.
Project description:Older age is a key predictor of severe COVID-19. To gain insight into this relationship, especially with respect to immune responses, we utilized the rhesus macaque model of SARS-CoV-2 infection. Two cohorts of eight older (16-23 years) and eight younger (3-5 years) rhesus macaques were inoculated with SARS-CoV-2. Four animals per group were euthanized at 7- and 21-days post inoculation (dpi). Our time-resolved evaluation included viral RNA quantification, clinical observations, thoracic radiographs, single-cell transcriptomics, multiparameter flow cytometry, multiplex immunohistochemistry, cytokine detection, and lipidomics analysis. Differences in clinical signs, pulmonary infiltrates, and virus replication dynamics were limited between age cohorts. Transcriptional signatures of inflammation-associated genes in cells isolated from bronchoalveolar lavage fluid at 3 dpi revealed efficient mounting of innate immune defenses in both younger and older animals. These findings suggest that age does not substantially skew major facets of acute disease in this model. However, age-specific divergence of immune responses emerged during the post-acute phase of infection (7-21 dpi). Older animals exhibited sustained local inflammatory innate responses while local effector T-cell responses were induced earlier in the younger animals. Circulating lipid mediator and cytokine levels highlighted increased repair-associated signals in the younger animals, in contrast to persistent pro-inflammatory responses in the older animals. In summary, despite similar disease outcomes, multi-omics profiling in SARS-CoV-2-infected rhesus macaques suggests that age may delay or impair the induction of anti-viral cellular immune responses and delay efficient return to immune homeostasis following acute infection.
Project description:The severe acute respiratory syndrome (SARS) epidemic was characterized by increased pathogenicity in the elderly due to an early exacerbated innate host response. SARS-CoV is a zoonotic pathogen that entered the human population through an intermediate host like the palm civet. To prevent future introductions of zoonotic SARS-CoV strains and subsequent transmission into the human population, heterologous disease models are needed to test the efficacy of vaccines and therapeutics against both late human and zoonotic isolates. Here we show that both human and zoonotic SARS-CoV strains can infect cynomolgus macaques and resulted in radiological as well as histopathological changes similar to those seen in mild human cases. Viral replication was higher in animals infected with a late human phase isolate compared to a zoonotic isolate. Host responses to the three SARS-CoV strains were similar and only apparent early during infection with the majority of genes associated with interferon signalling pathways.This study characterizes critical disease models in the evaluation and licensure of therapeutic strategies against SARS-CoV for human use 4 strains, time course, lungs
Project description:Single cell RNA sequencing analysis was performed on bronchoalveolar lavage samples obtained from Rhesus macaques on day 2 after intranasal/intratracheal infection with SARS-CoV-2 B.1.351/beta variant 4 weeks after the second dose of 30ug mRNA-1273 vaccine along with unvaccinated controls
Project description:Here we profiled about 77000 single-nucleus transcriptomes of lung, liver, kidney, and cerebral cortex from rhesus macaques infected with SARS-CoV-2. Our work of multi-organ single-nucleus transcriptomic survey of SARS-CoV-2 infected animal model expanded our understanding of disease features and antiviral immune defects caused by the novel coronavirus at cellular and molecular level, which may facilitate the development of potential therapeutic intervention for COVID-19.
Project description:Inflammation following SARS-CoV-2 infection is a hallmark of COVID-19 and predictive of morbidity and death. However, the inflammatory pathways contributing to host-defense vs immune-mediated pathology have not been fully elucidated. This duality is clearly seen with type-I interferons (IFN-I) which are critical mediators of innate control of viral infections, but also drive recruitment of inflammatory cells to site of infection, a key feature of severe COVID-19. Here, we modulated IFN-I signaling in rhesus macaques (Macaca mulatta) prior to and during acute SARS-CoV-2 infection (day -1 through day 2 post infection) using a mutated IFNα2 (IFN-modulator; IFNmod) which blocks binding to IFNAR2 and signaling of endogenous IFN-I. IFNmod treatment resulted in a highly significant and consistent reduction in SARS-CoV-2 viral load in BAL, lung, and hilar LN (>3-log difference) and upper airways (nasal swabs). IFNmod also potently reduced inflammatory cytokines and chemokines in BAL, expansion of inflammatory monocytes (CD14+CD16+), and lung pathogenesis. Furthermore, Siglec-1 expression, which has been shown to enhance SARS-CoV-2 infection, was rapidly downregulated in the lung and on monocytes of IFNmod-treated SARS-CoV-2 infected RMs. Notably, while RNAseq analysis showed that IFNmod induced a modest upregulation of antiviral IFN-stimulated genes (ISGs) in uninfected RMs, it resulted in a robust reduction in pathways associated with both antiviral and inflammatory ISGs in SARS-CoV-2-infected RMs. In conclusion, IFNmod treatment provides sufficient levels of type I IFN signaling that inhibit viral replication while also limiting hyperinflammation. IFN-I plays a vital role in regulating SARS-CoV-2 replication, but uncontrolled IFN signaling has a detrimental impact on inflammation and pathogenesis. A better understanding of the role of IFN-I pathways is essential for designing therapies targeting these pathways and aimed at limiting COVID-19 pathogenesis.
Project description:Understanding SARS-CoV-2 immune pathology is critical for the development of effective vaccines and treatments. Here, we employed unbiased serial whole-blood transcriptome profiling by weighted gene network correlation analysis (WGCNA) at pre-specified timepoints of infection to understand SARS-CoV-2-related immune alterations in a cohort of rhesus macaques (RMs) and African green monkeys (AGMs) presenting with varying degrees of pulmonary pathology. We found that the bulk of transcriptional changes occurred at day 3 post-infection and normalized to pre-infection levels by 3 weeks. There was evidence of coordination of transcriptional networks in blood (defined by WGCNA) and the nasopharyngeal SARS-CoV-2 burden as well as the absolute monocyte count. Pathway analysis of gene modules revealed prominent regulation of type I and type II interferon stimulated genes (ISGs) in both RMs and AGMs, with the latter species exhibiting a greater breadth of ISG upregulation. Notably, pathways relating to neutrophil degranulation were enriched in blood of SARS-CoV-2 infected AGMs, but not RMs. Our results elude to hallmark similarities as well as differences in the RM and AGM acute response to SARS-CoV-2 infection, and may help guide the selection of particular NHP species in modeling aspects of COVID-19 disease outcome.
Project description:SARS-CoV-2 primarily replicates in mucosal sites, and more information is needed about immune responses in infected tissues. We used rhesus macaques to model protective primary immune responses in tissues during mild COVID-19. Viral RNA levels were highest on days 1-2 post-infection and fell precipitously thereafter. 18F-fluorodeoxyglucose (FDG)-avid lung abnormalities and interferon (IFN)-activated myeloid cells in the bronchoalveolar lavage (BAL) were found on days ∼3-4. Virus-specific effector CD8 and CD4 T cells were detectable in the BAL and lung tissue on days ∼7-10, after viral RNA, lung inflammation, and IFN-activated myeloid cells had declined. Notably, SARS-CoV-2-specific T cells were not detectable in the nasal turbinates, salivary glands, and tonsils on day 10 post-infection. Thus, SARS-CoV-2 replication wanes in the lungs prior to T cell responses, and in the nasal and oral mucosa despite the apparent lack of Ag-specific T cells, suggesting that innate immunity efficiently restricts viral replication during mild COVID-19.