FXa cleaves the SARS-CoV-2 spike protein and blocks cell entry to protect against infection with inferior effects in B.1.1.7 variant

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human natural defense mechanisms against SARS-CoV-2 are largely unknown. Serine proteases (SPs) including furin and TMPRSS2 cleave SARS-CoV-2 spike protein, facilitating viral entry. Here, we show that FXa, a SP for blood coagulation, is upregulated in COVID-19 patients compared to non-COVID-19 donors and exerts anti-viral activity. Mechanistically, FXa cleaves the SARS-CoV-2 spike protein, which prevents its binding to ACE2, and thus blocks viral entry. Furthermore, the variant B.1.1.7 with several mutations is dramatically resistant to the anti-viral effect of FXa compared to wild-type SARA-CoV-2 in vivo and in vitro. The anti-coagulant rivaroxaban directly inhibits FXa and facilitates viral entry, whereas the indirect inhibitor fondaparinux does not. In a lethal humanized hACE2 mouse model of SARS-CoV-2, FXa prolonged survival while combination with rivaroxaban but not fondaparinux abrogated this protection. These preclinical results identify a previously unknown SP function and associated anti-viral host defense mechanism and suggest caution in considering direct inhibitors for prevention or treatment of thrombotic complications in COVID-19 patients.

Dual roles of a novel oncolytic viral vector-based SARS-CoV-2 vaccine: preventing COVID-19 and treating tumor progression

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Cancer patients are usually immunocompromised and thus are particularly susceptible to SARS-CoV-2 infection resulting in COVID-19. Although many vaccines against COVID-19 are being preclinically or clinically tested or approved, none have yet been specifically developed for cancer patients or reported as having potential dual functions to prevent COVID-19 and treat cancer. Here, we confirmed that COVID-19 patients with cancer have low levels of antibodies against the spike (S) protein, a viral surface protein mediating the entry of SARS-CoV-2 into host cells, compared with COVID-19 patients without cancer. We developed an oncolytic herpes simplex virus-1 vector-based vaccine named oncolytic virus (OV)-spike. OV-spike induced abundant anti-S protein neutralization antibodies in both tumor-free and tumor-bearing mice, which inhibit infection of VSV-SARS-CoV-2 and wild-type (WT) live SARS-CoV-2 as well as the B.1.1.7 variant in vitro. In the tumor-bearing mice, OV-spike also inhibited tumor growth, leading to better survival in multiple preclinical tumor models than the untreated control. Furthermore, OV-spike induced anti-tumor immune response and SARS-CoV-2-specific T cell response without causing serious adverse events. Thus, OV-spike is a promising vaccine candidate for both preventing COVID-19 and enhancing the anti-tumor response. One Sentence SummaryA herpes oncolytic viral vector-based vaccine is a promising vaccine with dual roles in preventing COVID-19 and treating tumor progression

The K18-hACE2 Transgenic Mouse Model Recapitulates Non-Severe and Severe COVID-19 in Response to Infectious Dose of SARS-CoV-2 Virus

A comprehensive analysis and characterization of a SARS-CoV-2 infection model that mimics non-severe and severe COVID-19 in humans is warranted for understating the virus and developing preventive and therapeutic agents. Here, we characterized the K18-hACE2 mouse model expressing human (h)ACE2 in mice, controlled by the human keratin 18 (K18) promoter, in epithelia, including airway epithelial cells where SARS-CoV-2 infections typically start. We found that intranasal inoculation with higher viral doses (2x103 and 2x104 PFU) of SARS-CoV-2 caused lethality of all mice and severe damage of various organs, including lungs, liver, and kidney, while lower doses (2x101 and 2x102 PFU) led to less severe tissue damage and some mice recovered from the infection. In this humanized hACE2 mouse model, SARS-CoV-2 infection damaged multiple tissues, with a dose-dependent effect in most tissues. Similar damage was observed in biopsy samples from COVID-19 patients. Finally, the mice that recovered after infection with a low dose of virus also survived rechallenge with a high dose of virus. Compared to other existing models, the K18-hACE2 model seems to be the most sensitive COVID-19 model reported to date. Our work expands the information available about this model to include analysis of multiple infectious doses and various tissues with comparison to human biopsy samples from COVID-19 patients. In conclusion, the K18-hACE2 mouse model recapitulates both severe and non-severe COVID-19 in humans and can provide insight into disease progression and the efficacy of therapeutics for preventing or treating COVID-19. ImportanceThe pandemic of COVID-19 has reached 112,589,814 cases and caused 2,493,795 deaths worldwide as of February 23, 2021, has raised an urgent need for development of novel drugs and therapeutics to prevent the spread and pathogenesis of SARS-CoV-2. To achieve this goal, an animal model that recapitulates the features of human COVID-19 disease progress and pathogenesis is greatly needed. In this study, we have comprehensively characterized a mouse model of SARS-CoV-2 infection using K18-hACE2 transgenic mice. We infected the mice with low and high doses of SARS-CoV-2 virus to study the pathogenesis and survival in response to different infection patterns. Moreover, we compared the pathogenesis of the K18-hACE2 transgenic mice with that of the COVID-19 patients to show that this model could be a useful tool for the development of anti-viral drugs and therapeutics.

Histological changes in human skin 32 days after death and the potential forensic significance.

To observe the histological changes in human skin within 32 days after death to explore its potential significance in forensic practice. The intact full-thickness skin and subcutaneous tissue from the sternum of eight corpses were placed in an environment of 4-6 °C for 4 h, 6 h, 12 h, 18 h, 24 h, 36 h, 48 h, 60 h, 72 h, 84 h, 96 h, 6 d, 8 d, 10 d, 12 d, 16 d, 20 d, 24 d, 28 d, and 32 d. Then, the whole layer of the skin was stained with haematoxylin & eosin. The histological morphology of the epidermis, dermis and appendages (sweat glands, hair follicles, and sebaceous glands) was observed under an light microscope. The epithelial nucleus condensed at 24 h after death, and cell lysis was exhausted after 20 days. The post-mortem changes in the dermis occurred later than that of the epidermis (72 h), but after epidermal changes started, the change was more rapid. At 16 d, the layers had become homogenized. The epidermis and dermis had completely separated 24 d after death. The changes in the sweat glands appeared earlier (24 h) and disappeared later (32 days); the sebaceous glands and hair follicles began to undergo degenerative changes at 96 h after death, and at approximately 20 d, only their contour remained. There were individual and structural differences in the post-mortem histological changes in the skin. At 4-6 °C ambient temperature, some structures of the human skin still exist for a long time after death, and these structures can be used to identify the source of the tissue; post-mortem histological changes in the skin occur at specific times, which can be used to help infer the time of death. A comprehensive observation of changes in the skin composition/structure is required to comprehensively analyse possible death times.

Epitope-resolved profiling of the SARS-CoV-2 antibody response identifies cross-reactivity with an endemic human CoV

A high-resolution understanding of the antibody response to SARS-CoV-2 is important for the design of effective diagnostics, vaccines and therapeutics. However, SARS-CoV-2 antibody epitopes remain largely uncharacterized, and it is unknown whether and how the response may cross-react with related viruses. Here, we use a multiplexed peptide assay ( PepSeq) to generate an epitope-resolved view of reactivity across all human coronaviruses. PepSeq accurately detects SARS-CoV-2 exposure and resolves epitopes across the Spike and Nucleocapsid proteins. Two of these represent recurrent reactivities to conserved, functionally-important sites in the Spike S2 subunit, regions that we show are also targeted for the endemic coronaviruses in pre-pandemic controls. At one of these sites, we demonstrate that the SARS-CoV-2 response strongly and recurrently cross-reacts with the endemic virus hCoV-OC43. Our analyses reveal new diagnostic and therapeutic targets, including a site at which SARS-CoV-2 may recruit common pre-existing antibodies and with the potential for broadly-neutralizing responses.

Clinical study on left ventricular remodeling patterns and its relationships with cardiovascular risk factors in patients with obstructive sleep apnea syndrome / 中华超声影像学杂志

Objective To investigate the left ventricular remodeling (LVR) patterns and its relationships with cardiovascular risk factors in patients with obstructive sleep apnea syndrome (OSAS).Methods 148 patients with habitual snoring were diagnosed OSAS by polysomnography with AHI≥5 /h and blood pressure was monitored at same time.The clinical characteristics were collected and echocardiography was done next morning.LVR patterns was categorized as normal geometry (NG),concentric remodeling (CR),eccentric hypertrophy (EH) and concentric hypertrophy (CH) on the basis of RWT ＞0.42 and LVMI ＞46.7 g/m2.7 (female) or 49.2 g/m2.7 (male).Multinomial logistic regression was used to analysis the correlation of cardiovascular risk factors and LVR patterns.Results ①Of 148 OSAS patients,there were 115 (77.7％) with abnormal LVR,NG 33 (22.3％),CR 35 (23.6％),EH 37 (25％)and CH 43 (29.1 ％).②General clinical characteristics:Compared with NG group,BMI and waistline were increased in EH group (P ＜0.05 or P ＜0.01) ; Age,BMI,waistline,hypertension,dSBP and nSBP were increased in CH group (P ＜0.05 or P ＜0.01).Compared with CR group,male,age,BMI and waistline were increased in EH group (P ＜0.05 or P ＜0.01).Male,age,BMI,waistline,hypertension,nSBP and TG were increased in CH group (P ＜ 0.05 or P ＜ 0.01); Compared with EH group,the prevalence of hypertension was increased in CH group (P ＜0.05); Compared with EH group,the prevalence of hypertension was increased in CH group (P＜0.05).③Polysomnography parameters:Compared with NG group,AHI and ODI were increased in CR group (P＜0.05 or P＜0.01).AHI,ODI and T90 were increased,while Mean SaO2 and Lowest SaO2 were decreased in CH group (P ＜0.05 or P ＜ 0.01);Compared with CR group,AHI was decreased in EH group (P ＜0.05).Mean SaO2 was decreased,but T90 was increased in CH group (P＜0.05 or P ＜0.01); Compared with EH group,Lowest SaO2 was decreased in CH group (P＜0.05).④Blood pressure:Compared with NG group,4:00 SBP and 6:00 SBP were increased in CH group (P＜0.05) ;Compared with CR group,22:00 SBP was increased in CH group (P ＜0.05).⑤ In multinomial logistic regression analysis,after adjusting the confounding factors,CR was associated with AHI [odds ratio (OR) 1.035,P =0.024.EH was associated with Age (OR 1.094,P =0.016),BMI (OR 1.397,P =0.011) and 4:00 SBP (OR 1.124,P =0.026).CH was associated with Age (OR 1.084,P =0.028).Conclusions OSAS could cause result in LVR and the prevalence of four patterns were similar..Age and AHI were significant determinants of CH and CR respectively.Age,BMI and 4:00 SBP were significant determinants of EH.

Evaluation of structure and stiffness of the common carotid artery in patients with obstructive sleep apnea syndrome by RF QIMT and RF QAS technology / 中华超声影像学杂志

Objective To evaluate the structure and stiffness of the common carotid artery (CCA) in patients with obstructive sleep apnea syndrome (OSAS) by RFQIMT and RFQAS technology and analyze the relationships between the parameters of CCA and cardiovascular risk factors.Methods 113 participants with habitual snoring suspected OSAS were divided into control group,mild,moderate and severe OSAS groups according to apnea hypopnea index(AHI)＜5,5-20,20-40,＞40 event/hour respectively.Carotid parameters included intima-media thickness (IMT),diameter (D),distension (Dis),distensibility coefficient (DC),compliance coefficient (CC),pulse wave velocity (PWV),stiffness index α and β were collected by RFQIMT and RFQAS.Multivariate linear regression analysis was applied to analyze the relationships between CCA parameters and cardiovascular risk factors.Results ①The clinical characteristics:blood pressure had significant difference among the four groups (P ＜0.05).SO2,SO2 min decreased and T90,ODI increased significantly in mild,moderate and severe group (P ＜0.05).②The structure parameters of CCA:IMT,D and plaques had no significant difference among the four groups (P ＞0.05).③The elasticity parameters of CCA:Compared with control group,Dis increased significantly in mild group (P ＜0.05).PWV,α,β increased significantly in moderate group (P ＜ 0.05).Compared with mild group,PWV,α,β increased significantly in moderate group (P ＜0.05).Compared with moderate group,α,β increased significantly in severe group (P ＜0.05).④By multivariate linear regression analysis,age was an independent predictor of IMT,Dis,D,CC,PWV,α,β(P ＜0.05).A blunted nocturnal fall was an independent predictor of D,DC,CC,PWV (P ＜0.05),SBP,DBP and PP of daytime had an important effect on D (P ＜0.05).SO2 was independently correlated with PWV (P ＜0.05).PP was an independent predictor of PWV,α,β (P ＜0.05).Smoking was an independent predictor of plaque (P ＜0.05).Conclusions ①Stiffness is damaged earlier than morphology of CCA in patient with OSAS.②PP,a blunted nocturnal fall and SO2 are correlated with stiffness of CCA significantly.It indicates that abnormal circadian blood pressure rhythm and hypoxia are associated significantly with stiffness of CCA in patient with OSAS.