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A complete diagnostic autopsy is the gold-standard to gain insight into Coronavirus disease 2019 (COVID-19) pathogenesis. To delineate the in situ immune responses to SARS-CoV-2 viral infection, here we perform comprehensive high-dimensional transcriptional and spatial immune profiling in 22 COVID-19 decedents from Wuhan, China. We find TIM-3-mediated and PD-1-mediated immunosuppression as a hallmark of severe COVID-19, particularly in men, with PD-1 + cells being proximal rather than distal to TIM-3 + cells. Concurrently, lymphocytes are distal, while activated myeloid cells are proximal, to SARS-CoV-2 viral antigens, consistent with prevalent SARS-CoV-2 infection of myeloid cells in multiple organs. Finally, viral load positively correlates with specific immunosuppression and dendritic cell markers. In summary, our data show that SARS-CoV-2 viral infection induces lymphocyte suppression yet myeloid activation in severe COVID-19, so these two cell types likely have distinct functions in severe COVID-19 disease progression, and should be targeted differently for therapy., (© 2022. The Author(s).)

A comprehensive analysis of the humoral immune response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential in understanding COVID-19 pathogenesis and developing antibody-based diagnostics and therapy. In this work, we performed a longitudinal analysis of antibody responses to SARS-CoV-2 proteins in 104 serum samples from 49 critical COVID-19 patients using a peptide-based SARS-CoV-2 proteome microarray. Our data show that the binding epitopes of IgM and IgG antibodies differ across SARS-CoV-2 proteins and even within the same protein. Moreover, most IgM and IgG epitopes are located within nonstructural proteins (nsps), which are critical in inactivating the host's innate immune response and enabling SARS-CoV-2 replication, transcription, and polyprotein processing. IgM antibodies are associated with a good prognosis and target nsp3 and nsp5 proteases, whereas IgG antibodies are associated with high mortality and target structural proteins (Nucleocapsid, Spike, ORF3a). The epitopes targeted by antibodies in patients with a high mortality rate were further validated using an independent serum cohort (n = 56) and using global correlation mapping analysis with the clinical variables that are associated with COVID-19 severity. Our data provide fundamental insight into humoral immunity during SARS-CoV-2 infection. SARS-CoV-2 immunogenic epitopes identified in this work could also help direct antibody-based COVID-19 treatment and triage patients., (© 2021. The Author(s).)

The novel coronavirus disease (COVID-19) has become a universally prevalent infectious disease. The causative virus of COVID-19 is severe acute respiratory syndrome coronavirus type 2. Recent retrospective clinical studies have established a significant association between the incidence of vascular thrombotic events and the severity of COVID-19. The enhancement in serum levels of markers that reflect a hypercoagulable state has been suggested to indicate a poor prognosis. Therefore, at present, it is crucial to understand the mechanisms that foster the hypercoagulable state in COVID-19. Over-activated inflammatory response, which is manifested as excessive cytokine release in COVID-19 patients, is also associated with COVID-19 severity. This review discusses the immuno-pathological basis of the excessive cytokine release in COVID-19. Besides, this article reviews the role of pro-inflammatory or anti-inflammatory cytokines, whose significant elevations in their serum levels have been consistently detected in multiple different clinical studies, in promoting the hypercoagulable state. Since the expression of angiotensin-converting enzyme 2 (ACE2) is potentially down-regulated in COVID-19, as proposed by a recent bio-informatic analysis, mechanisms through which reduced ACE2 expressions promote vascular thrombosis are summarized. In addition, the reciprocal-enhancing effects of the excessive cytokine release and the downregulated ACE2 expression on their pro-thrombotic activities are further discussed. Here, based on currently available evidence, we review the pathogenic mechanisms of the hypercoagulable state associated with severe cases of COVID-19 to give insights into prevention and treatment of the vascular thrombotic events in COVID-19.

Background: The emergence of COVID-19 has become a global health emergency. The transmissibility of the disease is of great interest to healthcare workers and scientists alike. The primary route of transmission is via respiratory droplets, but viral RNA has also been found in feces and body fluids such as urine, serum, and semen. So far, there has been no report on whether SARS-CoV-2 is present in the exudates of cutaneous lesions. This study was designed to investigate whether SARS-CoV-2 can be found in the pressure injury exudates in patients with severe COVID-19 infections., Methods: 46 critically ill COVID-19 patients who were admitted to the ICU of the Sino-French New City Branch of Tongji Hospital in Wuhan between February 4 and April 12 developed pressure injuries. 22 patients with pressure injuries had wound exudates. Wound and pharyngeal swabs of the 22 patients were collected and RT-PCRs were conducted to detect SARS-CoV-2 viral RNA., Results: At the time of pressure injury, 5 patients still tested positive by pharyngeal swabs, the rest of the 17 patients tested negative. However, none of the wound exudate swabs from the participants tested positive for SARS-CoV-2 by RT-PCR., Conclusion: Our study suggests that it is rather unlikely that COVID-19 can be transmitted via pressure injury exudates, but we still recommend standardized personal protective equipment, face shield and an additional pair of gloves when treating pressure injuries., (© 2020 Wiley Periodicals LLC.)

The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a current global threat for which there is an urgent need to search for an effective therapy. The transmembrane spike (S) glycoprotein of SARS-CoV-2 directly binds to the host angiotensin-converting enzyme 2 (ACE2) and mediates viral entrance, which is therefore considered as a promising drug target. Considering that new drug development is a time-consuming process, drug repositioning may facilitate rapid drug discovery dealing with sudden infectious diseases. Here, we compared the differences between the virtual structural proteins of SARS-CoV-2 and SARS-CoV, and selected a pocket mainly localizing in the fusion cores of S2 domain for drug screening. A virtual drug design algorithm screened the Food and Drug Administration-approved drug library of 1234 compounds, and 13 top scored compounds were obtained through manual screening. Through in vitro molecular interaction experiments, eltrombopag was further verified to possess a high binding affinity to S protein plus human ACE2 and could potentially affect the stability of the ACE2-S protein complex. Hence, it is worth further exploring eltrombopag as a potential drug for the treatment of SARS-CoV-2 infection., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Coronavirus disease 2019 (COVID‐19) patients with impact on skin and hair loss are reported. Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is detected in the skin of some patients; however, the detailed pathological features of skin tissues from patients infected with SARS‐CoV‐2 at a molecular level are limited. Especially, the ability of SARS‐CoV‐2 to infect skin cells and impact their function is not well understood. A proteome map of COVID‐19 skin is established here and the susceptibility of human‐induced pluripotent stem cell (hiPSC)‐derived skin organoids with hair follicles and nervous system is investigated, to SARS‐CoV‐2 infection. It is shown that KRT17+ hair follicles can be infected by SARS‐CoV‐2 and are associated with the impaired development of hair follicles and epidermis. Different types of nervous system cells are also found to be infected, which can lead to neuron death. Findings from the present work provide evidence for the association between COVID‐19 and hair loss. hiPSC‐derived skin organoids are also presented as an experimental model which can be used to investigate the susceptibility of skin cells to SARS‐CoV‐2 infection and can help identify various pathological mechanisms and drug screening strategies. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is causing considerable morbidity and mortality worldwide. Multiple reports have suggested that patients with heart failure (HF) are at a higher risk of severe disease and mortality with COVID-19. Moreover, evaluating and treating HF patients with comorbid COVID-19 represents a formidable clinical challenge as symptoms of both conditions may overlap and they may potentiate each other. Limited data exist regarding comprehensive management of HF patients with concomitant COVID-19. Since these issues pose serious new challenges for clinicians worldwide, HF specialists must develop a structured approach to the care of patients with COVID-19 and be included early in the care of these patients. Therefore, the Heart Failure Association of the European Society of Cardiology and the Chinese Heart Failure Association & National Heart Failure Committee conducted web-based meetings to discuss these unique clinical challenges and reach a consensus opinion to help providers worldwide deliver better patient care. The main objective of this position paper is to outline the management of HF patients with concomitant COVID-19 based on the available data and personal experiences of physicians from Asia, Europe and the United States. [ABSTRACT FROM AUTHOR]

[Display omitted] Nucleocapsid (N) protein plays crucial roles in the life cycle of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including the formation of ribonucleoprotein (RNP) complex with the viral RNA. Here we reported the crystal structures of the N-terminal domain (NTD) and C-terminal domain (CTD) of the N protein and an NTD-RNA complex. Our structures reveal a unique tetramer organization of NTD and identify a distinct RNA binding mode in the NTD-RNA complex, which could contribute to the formation of the RNP complex. We also screened small molecule inhibitors of N-NTD and N-CTD and discovered that ceftriaxone sodium, an antibiotic, can block the binding of RNA to NTD and inhibit the formation of the RNP complex. These results together could facilitate the further research of antiviral drug design targeting N protein. [ABSTRACT FROM AUTHOR]

• Significant negative correlation between IL-6 and platelet parameters was discovered. • Correlation between multiple cytokines and coagulation indicators was found. • Pro-inflammatory factors were found to be more associated to coagulation parameters. • Cytokines play an important role in the pathogenesis and evaluation of the condition of COVID-19. The novel SARS-CoV-2 caused a large number of infections and deaths worldwide. Thus, new ideas for an appropriated assessment of patients' condition and clinical treatment are of utmost importance. Therefore, in this study, the laboratory parameters of patients with coronavirus disease 2019 (COVID-19) were evaluated to identify the correlation between cytokine expression and other laboratory parameters. A retrospective and single-center study was performed in Wuhan, involving 83 severe or critical COVID-19 patients admitted to the intensive care unit (ICU). Laboratory parameters in ICU patients with laboratory-confirmed infection of SARS-CoV2 were collected. The association between parameters was assessed by Spearman's rank correlation. Patients' median age was 66 years (IQR, 57–73), and 55 (66%) were men. Among the 83 patients, 61 (73%) had 1 or more coexisting medical condition. The median concentration of IL-2R, IL-6, IL8, IL10, and TNFα were above the normal range, without IL-1β. A significant negative correlation between IL-6 and platelet count was discovered (r2 = −0.448, P < 0.001) as well as a significant correlation between IL-6 and other platelet parameters. Finally, a correlation between multiple cytokines and coagulation indicators was found, pro-inflammatory factors were found to be more associated to coagulation parameters, with the highest correlation between IL-6 and the International normalized ratio (INR) (r2 = 0.444, P < 0.001). Our results suggested that cytokines play an important role in the pathogenesis of COVID-19. In addition, IL-6 seems more relevant in the evaluation of the condition of COVID-19 patients. [ABSTRACT FROM AUTHOR]

The pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global crisis. Replication of SARS-CoV-2 requires the viral RNA-dependent RNA polymerase (RdRp) enzyme, a target of the antiviral drug remdesivir. Here we report the cryo–electron microscopy structure of the SARS-CoV-2 RdRp, both in the apo form at 2.8-angstrom resolution and in complex with a 50-base template-primer RNA and remdesivir at 2.5-angstrom resolution. The complex structure reveals that the partial double-stranded RNA template is inserted into the central channel of the RdRp, where remdesivir is covalently incorporated into the primer strand at the first replicated base pair, and terminates chain elongation. Our structures provide insights into the mechanism of viral RNA replication and a rational template for drug design to combat the viral infection. [ABSTRACT FROM AUTHOR]