Phylogeography of SARS-CoV-2 pandemic in Spain:a story of multiple introductions,micro-geographic stratification,founder effects,and super-spreaders

Spain has been one of the main global pandemic epicenters for coronavirus disease 2019(COVID-19).Here,we analyzed>41000 genomes(including>26000 high-quality(HQ)genomes)downloaded from the GISAID repository,including 1245(922 HQ)sampled in Spain.The aim of this study was to investigate genome variation of novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and reconstruct phylogeographic and transmission patterns in Spain.Phylogeographic analysis suggested at least 34 independent introductions of SARS-CoV-2 to Spain at the beginning of the outbreak.Six lineages spread very successfully in the country,probably favored by super-spreaders,namely,A2 a4(7.8%),A2 a5(38.4%),A2 a10(2.8%),B3 a(30.1%),and B9(8.7%),which accounted for 87.9% of all genomes in the Spanish database.One distinct feature of the Spanish SARS-Cov-2 genomes was the higher frequency of B lineages(39.3%,mainly B3 a+B9)than found in any other European country.While B3 a,B9,(and an important sub-lineage of A2 a5,namely,A2 a5 c)most likely originated in Spain,the other three haplogroups were imported from other European locations.The B3 a strain may have originated in the Basque Country from a B3 ancestor of uncertain geographic origin,whereas B9 likely emerged in Madrid.The time of the most recent common ancestor(TMRCA)of SARS-CoV-2 suggested that the first coronavirus entered the country around 11 February 2020,as estimated from the TMRCA of B3 a,the first lineage detected in the country.Moreover,earlier claims that the D614 G mutation is associated to higher transmissibility is not consistent with the very high prevalence of COVID-19 in Spain when compared to other countries with lower disease incidence but much higher frequency of this mutation(56.4% in Spain vs.82.4% in rest of Europe).Instead,the data support a major role of genetic drift in modeling the micro-geographic stratification of virus strains across the country as well as the role of SARS-CoV-2 super-spreaders.

Hepatitis B virus/hepatitis D virus epidemiology: Changes over time and possible future influence of the SARS-CoV-2 pandemic

Hepatitis D virus(HDV)is a defective liver-tropic virus that needs the helper function of hepatitis B virus(HBV)to infect humans and replicate.HDV is transmitted sexually or by a parenteral route,in co-infection with HBV or by super-infection in HBV chronic carriers.HDV infection causes acute hepatitis that may progress to a fulminant form(7%-14%by super-infection and 2%-3%by HBV/HDV co-infection)or to chronic hepatitis(90%by HDV super-infection and 2%-5%by HBV/HDV co-infection),frequently and rapidly progressing to cirrhosis or hepatocellular carcinoma(HCC).Peg-interferon alfa the only recommended therapy,clears HDV in only 10%-20%of cases and,consequently,new treatment strategies are being explored.HDV endemicity progressively decreased over the 50 years from the identification of the virus,due to improved population lifestyles and economic levels,to the use of HBV nuclei(t)side analogues to suppress HBV replication and to the application of universal HBV vaccination programs.Further changes are expected during the severe acute respiratory syndrome coronavirus-2 pandemic,unfortunately towards increased endemicity due to the focus of healthcare towards coronavirus disease 2019 and the consequently lower possibility of screening and access to treatments,lower care for patients with severe liver diseases and a reduced impulse to the HBV vaccination policy.

Management protocol for Fournier’s gangrene in sanitary regime caused by SARS-CoV-2 pandemic:A case report

BACKGROUND Fournier's gangrene(FG)is a serious,aggressive and often deadly polymicrobial infection of the soft tissues of the perineum,the rectum and the external genital organs.It is an anatomical subcategory of necrotizing fasciitis,which has a similar etiology and treatment strategy.CASE SUMMARY A 60-year-old man was admitted to the hospital during severe acute respiratory syndrome coronavirus 2 pandemic with complaints of fever up to 38.9°C,abdominal pain,and edema of the scrotum,the penis,the perineum,and the right gluteal region for 2 d.Computed tomography of the abdomen and the pelvis revealed extensive inflammatory infiltrations of the subcutaneous tissue of the hypogastrium,and the penis;along with liquefaction and presence of gas in the subcutaneous tissues of the scrotum,the perineum,and the right gluteal region.The patient was diagnosed with FG,and was urgently qualified to undergo surgery in the Department of Urology.After performing the necessary examinations,a resection of the necrotic tissues with bilateral orchiectomy and excision of the penile and scrotal skin was performed.After surgery,he was transferred to the intensive care unit for further management.CONCLUSION Early management prevents the resection of the other organs by inhibiting the contiguous spread of infection.

Tackling SARS-CoV-2 Pandemic: The Way Forward

The world is engaged in containing the COVID Pandemic and controlling further spread and deaths. The global spread of the virus has overwhelmed health systems, and caused widespread social and economic disruption. Some nations have done a better job than rest of the world. The global spread of the virus has overwhelmed health systems, and caused widespread social and economic disruption. There is a strong case that COVID-19 could be with us in one way or another until a vaccine comes on the market or herd immunity is achieved. A long crisis, could stretch the international order to its breaking point. The virus has succeeded in confining almost all human beings in their homes. Balancing act between public health crisis and complex societal implications is an inescapable necessity. The pandemic will alter the world forever. An economic slowdown, severe recession, plummeting revenue, increased expenditure, and mental health issues could be the emerging challenges. There will be increased confidence in technology and nations will invest more in public health. We are passing through fragile and critical times in history. People around the world can prevail in response to this extraordinary challenge. Investing in public health, preparedness, and relying on science will bring a better future. Think of one world, one humanity to shape and secure our future.

Self-Reported Use of Personal Protective Equipment during the SARS-CoV-2 Pandemic in Emergency Medical Service Employees in Germany—A Survey

Background: Multicentric prospective cohort investigation survey conducted between 1st of March and 1st of April 2021on SARS-CoV-2 occupational risk for German Emergency Medical Services (EMS) personnel. Study Objectives: Primary: The objective is to take stock of the use and availability of Personal Protective Equipment (PPE) in German EMS, both at managerial and employee level, during the SARS-CoV-2 pandemic. Secondary: Generate additional data on individual perceptions of risk of infection and occurrence of infections at respective places of service. Methods: Multicentric prospective cohort investigation survey conducted online at two levels of German EMS personnel—EMS managers and EMS employees, both medical and paramedical—with questions adapted slightly to fit the respective study population. Results: A total of 34 responses were received in the managerial group;a total of 2389 responses were received in the group of employees. Self-reported PPE adherence of EMS employees for confirmed SARS-CoV-2 positive patients: use of gloves (99.8%), FFP2 or FFP3 masks (99.8%), gowns or coveralls (99.1%), goggles (89.7%), face shields (24.0%), surgical masks (0.0%). Self-reported PPE adherence of EMS employees for suspected SARS-CoV-2 positive patients: gloves (98.8%), FFP2 or FFP3 masks (total: 99.4%), gowns or coveralls (total: 95.9%), goggles (85.6%), face shields (19.2%), surgical masks (0.2%). Conclusions: Findings included an overall improved self-reported adherence to PPE compared to studies that were conducted before the pandemic. Self-reported general adherence to PPE recommendations when attending to confirmed SARS-CoV-2 positive patients was good, with the exception of goggles. Self-reported adherence to PPE recommendations dropped when attending to suspected SARS-CoV-2 positive patients.

Implementation of lung ultrasound in the triage of pregnant women during the SARS-CoV-2 pandemics

Lung ultrasound(US)has been shown that it is able to detect interstitial lung disease,subpleural consolidations and acute respiratory distress syndrome in clinical and physical studies that assess its role in upper respiratory infections.It is used worldwide in the coronavirus disease 2019(COVID-19)outbreak and the effectiveness has been assessed in several studies.Fast diagnosis of COVID-19 is essential in deciding for patient isolation,clinical care and reducing transmission.Imaging the lung and pleura by ultrasound is efficient,cost-effective,and safe and it is recognized as rapid,repeatable,and reliable.Obstetricians are already using the US and are quite proficient in doing so.During the pandemic,performing lung US(LUS)right after the fetal assessment until reverse transcription polymerase chain reaction results are obtained,particularly in settings that have a centralized testing center,was found feasible for the prediction of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.The use of LUS is efficient in the triage and monitoring of pregnant women.Clinicians dealing with pregnant women should consider LUS as the first-line diagnostic tool in pregnant women during the SARS-CoV-2 pandemic.

Psychiatric hospitalization during the two SARS-CoV-2 pandemic waves:New warnings for acute psychotic episodes and suicidal behaviors

BACKGROUND The subsequent waves of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)pandemic have represented a dramatic health emergency characterized by significant consequences on mental health.Diachronic variations in the incidence rates of acute relapse of psychiatric disorders may represent significant"sentinel events"for assessing the mental health response to an unprecedented stressful event.AIM To investigate the variation in psychiatric hospitalization rates and differences in sociodemographic and clinical-psychopathological peculiarities at Bologna"Maggiore"General Hospital Psychiatric Ward(GHPW)between the first two waves SARS-CoV-2 pandemic and the same periods of the previous 3 years.The secondary purpose of the study was to suggest a diachronic response pathway to stress by reporting additional literature data on coping strategies.METHODS This observational and retrospective study collected information on admission to the GHPW at the"Maggiore"Hospital in Bologna in the index periods defined as follows:the first period between February 24,2020 and April 30,2020(first epidemic wave)and the second period between October 8,2020,and January 7,2021(second pandemic wave).Absolute numbers and proportion of admitted patients,their sociodemographic and clinical-psychopathological characteristics were compared with the same parameters recorded in the two same periods of the previous 3 years.No strict inclusion or exclusion criteria were provided in the data collection to collect information on all patients requiring acute psychiatric hospitalization.RESULTS During the first wave,there was a significant reduction in hospitalization rates,although there was a simultaneous increase in compulsory hospitalizations and the acute relapse of schizophrenia spectrum and other psychotic disorders.During the second wave,hospitalization rates reached those recorded during the same period of the previous 3 years,mainly due to the rise of bipolar and related disorders,depressive disorders,anxiety disorders,trauma-and stressor-related disorders and suicidal behaviors.CONCLUSION The coping strategies adopted during the first wave of the SARS-CoV-2 pandemic protected the vulnerable population from the general risk of clinical-psychopathological acute relapse,even if they increased the susceptibility to run into schizophrenia spectrum and other psychotic disorder relapses.In the medium-long term(as in the second pandemic wave),the same strategies do not play protective roles against the stress associated with the pandemic and social restriction measures.Indeed,during the second wave of the SARS-CoV-2 pandemic,an increase in total hospitalization rate,suicidal behaviors and the incidence rate of bipolar and related disorders,depressive disorders,anxiety disorders,trauma-and stressorrelated disorders was observed.

Impacts of SARS-CoV-2 on diabetes mellitus:A pre and post pandemic evaluation

The coronavirus disease 2019(COVID-19)pandemic caused by the novel beta coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)crippled the whole world and has resulted in large number of morbidity and mortality.The origin of the SARS-CoV-2 is still disputed.The risk of infection with SARS-CoV-2 is dependent on several risk factors as observed in many studies.The severity of the disease depends on many factors including the viral strain,host immunogenetics,environmental factors,host genetics,host nutritional status and presence of comorbidities like hypertension,diabetes,Chronic Obstructive Pulmonary Disease,cardiovascular disease,renal impairment.Diabetes is a metabolic disorder mainly characterized by hyperglycemia.Diabetic individuals are intrinsically prone to infections.SARS-CoV-2 infection in patients with diabetes result inβ-cell damage and cytokine storm.Damage to the cells impairs the equilibrium of glucose,leading to hyperglycemia.The ensuing cytokine storm causes insulin resistance,especially in the muscles and liver,which also causes a hyperglycemic state.All of these increase the severity of COVID-19.Genetics also play pivotal role in disease pathogenesis.This review article focuses from the probable sources of coronaviruses and SARS-CoV-2 to its impacts on individuals with diabetes and host genetics in pre-and post-pandemic era.

SARS-CoV-2合并感染患者的病原微生物分布特征及耐药性分析

目的分析严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)合并感染患者病原微生物分布特点及耐药情况,为临床诊治提供依据。方法收集2022年12月至2023年2月延安大学附属医院收治的2019冠状病毒病(corona virus disease 2019,COVID-19)患者637例的临床资料,回顾性分析其临床特征及合并感染病原微生物情况。结果COVID-19患者以老年人为主,合并基础疾病患者占79.59%,好转及痊愈患者高达91.05%。培养阳性标本来源于呼吸道、血液和尿液,合并感染的病原微生物分别以肺炎克雷伯杆菌、凝固酶阴性葡萄球菌(coagulase negative staphylococci,CNS)和真菌为主。药敏试验结果显示,肺炎克雷伯杆菌对β内酰胺类抗生素及三代、四代头孢菌素类抗生素耐药率较低(14%~20%),鲍曼不动杆菌对氨基糖苷类抗生素和β内酰胺类复合物较为耐药(均>45%),大肠埃希菌对β内酰胺类抗生素及其复合物耐药率较低(14%~19%)。金黄色葡萄球菌、CNS、屎肠球菌、粪肠球菌均未发现对万古霉素、利奈唑胺、替加环素耐药。结论COVID-19合并感染病原体以革兰阴性菌及真菌为主,感染部位以呼吸道为主,主要病原菌为肺炎克雷伯杆菌。鲍曼不动杆菌对氨基糖苷类抗生素和β内酰胺类复合物耐药率高于全国细菌耐药平均水平,提示临床上应根据COVID-19患者的微生物鉴定和药敏试验结果,选择对症药物治疗,以改善患者预后。

糖尿病患者接种SARS-Cov-2疫苗后的免疫反应:系统评价

目的系统评价糖尿病患者在接种SARS-CoV-2疫苗后的体液和细胞免疫反应。方法检索Web of Science、PubMed、中国知网、万方数据知识服务平台、维普中文科技期刊全文数据库和中国生物医学文献数据库,获取国内外于2019年12月1日至2022年5月12日公开发表的有关糖尿病患者接种SARS-CoV-2疫苗后的体液和细胞免疫反应的观察性研究,经由2名研究者独立筛选文献和提取资料后,采用美国国立卫生研究质量评价工具对纳入文献进行偏倚风险评价,使用描述性统计方法进行汇总分析。结果13篇文献共纳入66651例研究对象,其中5874例(7.9%)患有糖尿病。7篇文献报道了接种第1剂疫苗后糖尿病患者和对照组的免疫反应,其中3篇文献表明,接种1剂SARS-CoV-2疫苗后,糖尿病患者血清抗体水平和阳性率低于对照组;11篇涉及接种2剂SARS-CoV-2疫苗后的免疫反应的文献中,2篇报道了糖尿病患者可产生与对照组相似的抗体反应,9篇报道了糖尿病患者的血清抗体水平、阳性率或细胞免疫反应低于对照组。结论接种SARS-CoV-2疫苗后糖尿病患者和对照组体液和细胞免疫反应均有所增加,但糖尿病患者增加幅度普遍低于对照组。

hiPSCs分化的细胞和类器官在SARS-CoV-2感染研究上的应用

SARS-CoV-2引起全球性传染病COVID-19的大流行,SARS-CoV-2感染研究对于了解人体细胞和器官被此种病毒感染后的病理反应具有重要意义。将hiPSCs分化为呼吸道、肺类器官、神经系统细胞、脑类器官、心肌细胞、血管、肠类器官和肾类器官,进行SARS-CoV-2感染研究,发现这些细胞和类器官受SARS-CoV-2感染,生理活性受损,生理功能削弱,促炎性因子分泌增加,类器官发生炎症反应和功能退化现象。因此,hiPSCs分化的细胞和类器官可用于SARS-CoV-2感染研究,病毒感染会影响这些细胞和类器官的功能。

SARS-CoV-2重组痘苗病毒疫苗rVTT△TK-RBD的构建、筛选及免疫原性研究

目的 构建重组痘苗病毒载体疫苗rVTT△TK-RBD,并评价其安全性和免疫原性。方法 参考严重急性呼吸综合征冠状病毒2(SARS-CoV-2)基因序列合成受体结合域(RBD)基因,并将其插入自主构建的重组质粒pSTKE的多克隆位点上,构建重组痘苗病毒穿梭载体pSTKE-RBD,并转染到预先感染天坛株痘苗病毒(VTT)的BHK-21细胞内,经多轮的荧光噬斑筛选成功获得重组痘苗病毒rVTT△TK-RBD;通过滴鼻方式免疫小鼠后,检测rVTT△TK-RBD对BALB/c小鼠体质量的影响;通过肌肉免疫小鼠后,分析rVTT△TK-RBD对BALB/c小鼠产生的特异性抗体和中和抗体的水平;通过流式细胞术检测rVTT△TK-RBD对BALB/c小鼠T细胞亚群的影响。结果 利用同源重组、增强型绿色荧光蛋白(EGFP)筛选标记和多次荧光噬斑筛选,成功筛选获得了表达RBD的胸腺激酶(TK)基因缺失型重组痘苗病毒rVTT△TK-RBD,且PCR验证成功。BALB/c小鼠体内实验表明rVTT△TK-RBD具有较好的抗SARS-CoV-2的免疫原性且相比于亲本株VTT明显降低了对机体的毒性作用。结论 成功构建并获得SARS-CoV-2重组痘苗病毒疫苗rVTT△TK-RBD并通过各项试验证明其安全性和免疫原性。

基于双核酸适配体的磁珠-SERS标签三明治结构用于SARS-CoV-2病毒表面S蛋白的快速检测

面对新型冠状病毒2019(COVID-19)传播速度极快的情况,发展快速、准确和低成本的诊断方法以检测SARS-CoV-2病毒的特定抗原非常必要。基于逆转录聚合酶链反应(RT-PCR)的COVID-19检测需要特定的实验室,耗时较长。本文针对SARS-CoV-2刺突蛋白,提出了一种基于核酸适配体特异性识别的一步捕获底物和检测探针的表面增强拉曼光谱(SERS)检测平台。利用模拟病毒(PSV)进行实验,不经预处理,在5 min内用便携式拉曼光谱仪检测SARS-CoV-2病毒及其变异株。实验结果表明,针对模拟病毒的检出限为200 TU/mL。此外,该方法可以检测另外5种SARS-CoV-2的变异病毒株,咽拭子体系中的极限检测限可以达到5000 TU/mL。实际大批量咽拭子的实验结果可以达到特异性为100%的效果。因此,该平台在SARS-CoV-2的医护点快速诊断中具有很大的应用潜力。

SARS-CoV-2 ORF7a通过靶向IKKβ激活NF-κB信号通路促进细胞炎症因子释放

目的:探究SARS-CoV-2辅助蛋白ORF7a介导NF-κB激活,进而诱导炎症因子产生的分子机制。方法:双荧光素酶报告基因试验检测ORF7a对NF-κB激活的影响,qRT-PCR检测ORF7a对细胞中炎症因子表达的影响,Western blot、核质分离及免疫荧光技术检测ORF7a蛋白对p65磷酸化及入核的影响,免疫共沉淀及免疫荧光技术检测ORF7a的作用靶标蛋白。结果:报告基因试验表明ORF7a显著激活NF-κB启动子活性,并呈剂量依赖性(P<0.001),而对AP-1报告基因的激活无明显影响。ORF7a显著上调细胞因子TNF-α、IL-β及IL-8 mRNA表达(P<0.05)。Western blot结果显示ORF7a显著增强p65蛋白磷酸化(P<0.05)及p65的入核(P<0.01)。免疫共沉淀实验发现ORF7a与NF-κB信号通路分子IKKβ蛋白存在相互作用,免疫荧光实验也证实ORF7a与IKKβ具有共定位。结论:SARS-CoV-2 ORF7a通过靶向IKKβ激活NF-κB信号通路,进而促进细胞中炎症因子的释放。

SARS-CoV-2广谱中和抗体性质鉴定

目的:对严重急性呼吸综合征冠状病毒2(SARS-CoV-2)广谱中和抗体XMA09进行性质鉴定,探究其广谱中和突变株的潜在机制,为SARS-CoV-2的疫苗设计与广谱中和抗体筛选提供参考。方法:通过ExpiCHO真核表达系统与Protein A层析柱表达纯化XMA09蛋白;冷冻电镜技术确定XMA09识别的受体结构域(RBD)上的关键氨基酸位点;间接ELISA与表面等离子共振(SPR)技术检测XMA09对SARS-CoV-2及其突变株Spike蛋白的亲和力;采用基于水疱性口炎病毒(VSV)的假病毒系统检测XMA09对SARS-CoV-2野生型及突变株的中和能力。结果:本研究发现XMA09识别的表位较为保守,对多种突变株Spike蛋白均具有强结合能力,能广谱中和关切突变株(VOCs),包括广泛流行的Omicron亚突变株BA.4/5。结论:XMA09是SARS-CoV-2广谱中和抗体,具有作为SARS-CoV-2治疗性抗体的潜力,并可为SARS-CoV-2的广谱疫苗设计与抗体药物开发提供参考意义。

槲皮素通过抑制ACE2治疗SARS-CoV-2所致心肌损伤的研究进展

2019年底,由重症急性呼吸道综合征冠状病毒2(SARS-CoV-2)引起的新型冠状病毒病肺炎(COVID-19)在全球迅速蔓延,由于其潜伏期长、传播性强、突变率高,因此,COVID-19的防治已成为全球卫生领域的焦点问题。由于人体呼吸道黏膜表面血管紧张素转换酶2(angiotensin converting enzyme 2,ACE2)含量丰富,而SARS-CoV-2表面的刺突蛋白(S蛋白)具有介导受体识别和结合功能,其受体结构域可特异性结合ACE2的肽酶结构域。因此,ACE2是作为SARS-CoV-2感染的宿主的途径,在SARS-CoV-2感染机体过程中发挥至关重要的作用。与此同时,心肌组织ACE2含量较丰富,且COVID-19合并心肌损伤患者心肌组织ACE2呈现表达异常。而我国传统中医药六大处方防治COVID-19疗效显著,其中,共有中药单体成分槲皮素备受关注,防治机制可能与槲皮素抑制ACE2密切相关。迄今为止,少有SARS-CoV-2所致心肌损伤药物治疗的相关报道。因此,本文旨在通过文献汇总和生信预测探讨槲皮素是否通过抑制ACE2在心肌组织中的高表达从而改善COVID-19所致心肌损伤,从而降低COVID-19患者心源性死亡率及心血管并发症。

黄芩苷对SARS-COV-2侵袭的抑制作用研究

目的在体外研究黄芩苷对新型冠状病毒(SARS-CoV-2)入侵细胞过程的抑制作用。方法利用构建有荧光素酶报告基因的SARS-CoV-2 S蛋白假病毒系统,通过荧光素酶试剂盒检测加入黄芩苷和假病毒后Huh-7细胞中的荧光素表达变化,进而绘制病毒抑制曲线。结果黄芩苷能显著抑制Huh-7细胞的病毒感染率,黄芩苷和病毒提前共孵育组与直接加入组在不同浓度下的病毒抑制曲线并无显著差别,表明黄芩苷并不能与病毒直接结合,而是通过作用于病毒S蛋白介导的细胞融合过程产生抑制作用;黄芩苷在0.125 mg·mL^(-1)浓度时,对病毒的抑制率在4 h组显著降低,在0 h和2 h组并无显著差别,表明黄芩苷可能在病毒入侵细胞(非吸附)阶段产生抑制作用,且介导的入侵抑制阶段发生在4 h内。结论黄芩苷可能通过介导抑制SARS-CoV-2病毒S蛋白与细胞表面受体的融合过程,在非吸附阶段抑制病毒的入侵,发挥抗新冠病毒活性。

马铃薯三糖甘草次酸衍生物通过抑制SARS-CoV-2进入靶细胞作为潜在的小分子新冠病毒融合抑制剂

目的 研究马铃薯三糖甘草次酸衍生物能否通过抑制SARS-CoV-2进入靶细胞,作为潜在的小分子新冠病毒融合抑制剂。方法 以天然SARS-CoV-2进入抑制剂甘草酸为先导化合物,利用活性亚结构的拼合原理等设计并合成了系列马铃薯三糖甘草次酸衍生物。利用SARS-CoV-2假病毒体外细胞感染模型,检测该系列甘草次酸衍生物的体外抗SARS-CoV-2活性;利用表面等离子共振技术及假病毒模型寻找先导化合物1b的抗病毒作用靶点;利用SARS-CoV-2 S蛋白介导的细胞-细胞融合体系,检测先导化合物1b是否作用于SARS-CoV-2病毒入侵宿主的膜融合过程;基于分子对接与定点突变技术,确定先导化合物1b与S蛋白的作用模式等。结果 先导化合物1b对SARS-CoV-2奥密克戎假病毒有显著抑制作用,EC50值为3.28μmol/L(P<0.05),对其它SARS-CoV-2变异株假病毒有广谱抗病毒活性。细胞-细胞膜融合实验显示1b能够抑制合胞体的形成。分子对接预测先导化合物1b可与S1与S2亚基交界处的空腔中的Glu309、Ser305、Arg765、Lys964等多个保守氨基酸残基产生氢键作用,亲和力为-8.6 kcal/mol。化合物1b在10、5、2.5、1.25μmol/L时对Arg765、Lys964、Glu309和Leu303突变后的假病毒的抑制活性显著降低(P<0.01)。结论 马铃薯三糖甘草次酸衍生物能够靶向作用于S蛋白,特异性干扰病毒-细胞膜融合阶段,继而发挥抗SARS-CoV-2感染的作用,是一类结构新颖的小分子SARS-CoV-2融合抑制剂。

SARS-CoV-2主蛋白酶的表达、纯化和一种新型晶体结构的研究

新型冠状病毒SARS-CoV-2的主蛋白酶(Main Protease, Mpro),也称为3-糜蛋白酶样蛋白酶(3CLpro),在病毒复制的过程中发挥核心作用。Mpro的结构和功能在β-冠状病毒中相对保守,在人体内没有同源蛋白,因此是抗病毒药物开发的关键靶点。本研究完成了SARS-CoV-2 Mpro的原核表达与纯化,获得具有高纯度和高均一性的蛋白质样品。利用气相扩散坐滴法开展了Mpro的结晶筛选,获得单晶体后将其浸泡在由谷胱甘肽包裹的金团簇纳米材料溶液中,成功解析了仅有第156位半胱氨酸结合一个金离子的一个新型X射线衍射晶体结构。结构分析发现,Mpro蛋白的Cys156结合金离子后Asp153~Cys156区域的构象发生了~0.6 Å的偏移,推测该构象变化进一步通过变构效应抑制Mpro的生物功能,为新冠病毒的纳米型抑制剂的研发提供了新的信息。

COVID-19 vaccination produces exercise-responsive SARS-CoV-2 specific T-cells regardless of infection history

Background:The mobilization and redistribution of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)specific T-cells and neutralizing antibodies(nAbs)during exercise is purported to increase immune surveillance and protect against severe coronavirus disease 2019(COVID-19).We sought to determine if COVID-19 vaccination would elicit exercise-responsive SARS-CoV-2 T-cells and transiently alter nAb titers.Methods:Eighteen healthy participants completed a 20-min bout of graded cycling exercise before and/or after receiving a COVID-19 vaccine.All major leukocyte subtypes were enumerated before,during,and after exercise by flow cytometry,and immune responses to SARS-CoV-2 were determined using whole blood peptide stimulation assays,T-cell receptor(TCR)-βsequencing,and SARS-CoV-2 nAb serology.Results:COVID-19 vaccination had no effect on the mobilization or egress of major leukocyte subsets in response to intensity-controlled graded exercise.However,non-infected participants had a significantly reduced mobilization of CD4+and CD8+naive T-cells,as well as CD4+central memory T-cells,after vaccination(synthetic immunity group);this was not seen after vaccination in those with prior SARS-CoV-2 infection(hybrid immunity group).Acute exercise after vaccination robustly mobilized SARS-CoV-2 specific T-cells to blood in an intensity-dependent manner.Both groups mobilized T-cells that reacted to spike protein;however,only the hybrid immunity group mobilized T-cells that reacted to membrane and nucleocapsid antigens.nAbs increased significantly during exercise only in the hybrid immunity group.Conclusion:These data indicate that acute exercise mobilizes SARS-CoV-2 specific T-cells that recognize spike protein and increases the redistribution of nAbs in individuals with hybrid immunity.