Understanding the accessory viral proteins unique to the severe acute respiratory syndrome (SARS) coronavirus

A novel coronavirus, termed the severe acute respiratory syndrome coronavirus (SARS-CoV), infected humans in Guangdong, China, in November 2002 and the subsequent efficient human-to-human transmissions of this virus caused profound disturbances in over 30 countries worldwide in 2003. Eventually, this epidemic was controlled by isolation and there has been no human infection reported since January 2004. However, research on different aspects of the SARS-CoV is not waning, as it is not known if this virus will re-emerge, especially since its origins and potential reservoir(s) are unresolved. The SARS-CoV genome is nearly 30 kb in length and contains 14 potential open reading frames (ORFs). Some of these ORFs encode for genes that are homologous to proteins found in all known coronaviruses, namely the replicase genes (ORFs 1a and 1b) and the four structural proteins: nucleocapsid, spike, membrane and envelope, and these proteins are expected to be essential for the replication of the virus. The remaining eight ORFs encodes for accessory proteins, varying in length from 39 to 274 amino acids, which are unique to SARS-CoV. This review will summarize the expeditious research on these accessory viral proteins in three major areas: (i) the detection of antibodies against accessory proteins in the serum of infected patients, (ii) the expression, processing and cellular localization of the accessory proteins, and (iii) the effects of the accessory proteins on cellular functions. These in-depth molecular and biochemical characterizations of the SARS-CoV accessory proteins, which have no homologues in other coronaviruses, may offer clues as to why the SARS-CoV causes such a severe and rapid attack in humans, while other coronaviruses that infect humans seem to be more forgiving.     

Recent patents on treatment of severe acute respiratory syndrome (SARS)

Severe acute respiratory syndrome (SARS) is an epidemic that spread worldwide in early 2003. The aetiological agent was originally defined as a novel coronavirus and later designated as the SARS coronavirus (SARS-CoV), which appears similar to other coronaviruses in both virion structure and genome organization with a single-stranded, plus-sense RNA. However, the epidemiology and pathogenesis of SARS remain poorly understood and there is currently no effective treatment. To date, considerable research has been done on detection, prevention and treatment of SARS. In this review, we mainly focus on the recent patents and research work on detecting, preventing and treating SARS.     

严重急性呼吸道综合征的影像学分析

目的 :探讨严重急性呼吸道综合征 (SARS)的影像学特点。方法 :对临床确诊的 3 8例SARS患者的X线胸片和CT影像进行回顾性分析。结果 :X线表现轻度 18例 ( 4 7% ) ,中度 14例 ( 3 7% ) ,重度 6例 ( 16% ) ,中、重度患者病变均累及双侧。结论 :SARS同时存在急性肺炎和急性间质性肺炎 ,影像检查对SARS的诊断有重要价值 ,但要注意和普通肺炎、免疫功能损害患者肺炎及一些非感染性疾病肺部表现相鉴别。     

严重急性呼吸道综合征的影像学分析

目的:探讨严重急性呼吸道综合征(SARS)的影像学特点.方法:对临床确诊的38例SARS患者的X线胸片和CT影像进行回顾性分析.结果:X线表现轻度18例(47%),中度14例(37%),重度6例(16%),中、重度患者病变均累及双侧.结论:SARS同时存在急性肺炎和急性间质性肺炎,影像检查对SARS的诊断有重要价值,但要注意和普通肺炎、免疫功能损害患者肺炎及一些非感染性疾病肺部表现相鉴别.     

Efficient induction of cytotoxic T lymphocytes specific for severe acute respiratory syndrome (SARS)-associated coronavirus by immunization with surface-linked liposomal peptides derived from a non-structural polyprotein 1a

Spike and nucleocapsid are structural proteins of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) and major targets for cytotoxic T lymphocytes (CTLs). In contrast, non-structural proteins encoded by two-thirds of viral genome are poorly characterized for cell-mediated immunity. We previously demonstrated that nucleocapsid-derived peptides chemically coupled to the surface of liposomes effectively elicited SARS-CoV-specific CTLs in mice. Here, we attempted to identify HLA-A*0201-restricted CTL epitopes derived from a non-structural polyprotein 1a (pp1a) of SARS-CoV, and investigated whether liposomal peptides derived from pp1a were effective for CTL induction. Out of 30 peptides predicted on computational algorithms, nine peptides could significantly induce interferon gamma (IFN-γ)-producing CD8⁺ T cells in mice. These peptides were coupled to the surface of liposomes, and inoculated into mice. Six liposomal peptides effectively induced IFN-γ-producing CD8⁺ T cells and seven liposomal peptides including the six peptides primed CTLs showing in vivo killing activities. Further, CTLs induced by the seven liposomal peptides lysed an HLA-A*0201 positive cell line expressing naturally processed, pp1a-derived peptides. Of note, one of the liposomal peptides induced high numbers of long-lasting memory CTLs. These data suggest that surface-linked liposomal peptides derived from pp1a might offer an efficient CTL-based vaccine against SARS.     

严重急性呼吸综合征冠状病毒2潜在治疗药物概述

2019年12月以来湖北省武汉市严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)在省内、全国甚至境外其他国家爆发,并迅速蔓延,出现了聚集性病例,发热、干咳、乏力为主要临床表现,少数患者伴有鼻塞、流涕、咽痛和腹泻等症状。目前尚无来自随机对照试验的证据支持治疗SARS-CoV-2疑似或确诊病例的药物,迫切需要更好地了解这种新型冠状病毒并研发治疗感染该病毒患者的药物。根据前期研究资料发现可能在临床获益的一些药物,以期能为其他医疗机构在SARS-CoV-2的诊疗以及药物合理选择、药物研发提供参考。     

SARS诊断和鉴别诊断的几个问题

传染性非典型肺炎(SARS)是一种新出现的、具有明显传染性、可累及多个脏器和系统的特殊肺炎,对它的病原学、流行病学、发病机制、临床特征、影响预后等因素有待更进一步深入研究.虽然经过2003年的临床实践,中华医学会、中华中医药学会颁布的诊疗方案日趋完善,但由于人们对它的认识不深刻,绝大多数医务人员尚未接触到实际病例,疾病的临床表现不具特征性,加之其他因素的影响,给临床诊断带来了一定困难,甚至有的还出现误诊漏诊的现象.     

Synthesis of novel test compounds for antiviral chemotherapy of severe acute respiratory syndrome (SARS)

This contribution reviews the synthesis of a range of experimental drugs designed for and aiming at antiviral chemotherapy of severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV)-induced human disease conditions. The selection of 25 test materials includes eleven trioxa-adamantane-triols (TATs) [BN, IBNCA, ABNCA, VANBA, ethylVANBA, euBN, euVANBA, ansaBN, Ehrlich BN, [6]prismaneBN, nitrodiBN], trivially termed bananins, one trioxa-adamantan-ol (TAO) THYMOBA, one bis-bananin pi-bananin (piBN), one triazaadamantane delta-bananin (deltaBN), seven potential nucleic acid-binding drugs (XBQC, INDO, PivINDO, AZTRION, AZADO, AZOCYS, AZOGALL), one potential antiviral interferon-inducer and distant nucleoside analog diazon, one potential HIV protein Vif antagonist AZODIAZON, one folic acid-diazon condensate DIAZONOFOL, and one special nucleoside analog (fructoinosine/fructovir). Four of the eleven bananins (BN, IBNCA, VANBA, euBN) were already demonstrated to constitute effective inhibitors of SARS-CoV NSP10/nsp13 RNA/DNA helicase/NTPase protein ATPase enzymatic function. Bananin (BN) was an effective inhibitor of both SARS-CoV RNA/DNA helicase nucleic acid unwinding function and SARS-CoV (Coronaviridae, Coronavirus) RNA-viral replication in cell culture. In summary, at least one selected compound of the synthesized test materials represents an interesting drug candidate for treatment of SARS-CoV-induced human disease (SARS). Viewed in aspects of organic chemistry [6]prismaneBN and nitrodiBN are the first true hexaprismane derivatives synthesized, and all reported compounds are entirely new.     

Severe acute respiratory syndrome (SARS): the pharmacist's role

OBJECTIVES: After two outbreaks of severe acute respiratory syndrome (SARS) occurred in Toronto, Ontario, Canada, from March-June 2003, we reviewed the unexpected role and responsibilities of pharmacists during these two crises, and present strategies for better crisis preparedness. METHODS AND RESULTS: Pharmacists were actively involved in battling the SARS crises. After conducting extensive literature searches and evaluations, pharmacists prepared administration and dosing guidelines for the two investigational drugs, ribavirin and interferon alfacon-1, that were being used to treat the syndrome. They provided direct patient care under modified conditions. They revised drug distribution procedures and developed new ones to meet more stringent infection-control standards. Collaborative teamwork with key stakeholders was important in accomplishing tasks in an efficient and timely manner. Regular communication with health care staff took place internally and externally. Education and updated information for pharmacists was crucial. CONCLUSION: Pharmacists can play a vital role during crises in the areas of drug distribution, drug information, and direct patient care. Collaborative teamwork and close communication are keys to success. Pharmacists must be proactive and take a leadership role in assuming pharmacy-related responsibilities. By evaluating what worked and what didn't, pharmacists can develop procedures for future crises requiring pharmacy support.     

Thiopurine analogues inhibit papain-like protease of severe acute respiratory syndrome coronavirus

The papain-like protease of severe acute respiratory syndrome coronavirus (PLpro) (EC 3.4.22.46) is essential for the viral life cycle and therefore represents an important antiviral target. We have identified 6MP and 6TG as reversible and slow-binding inhibitors of SARS-CoV PLpro, which is the first report about small molecule reversible inhibitors of PLpro. The inhibition mechanism was investigated by kinetic measurements and computer docking. Both compounds are competitive, selective, and reversible inhibitors of the PLpro with K(is) values approximately 10 to 20 microM. A structure-function relationship study has identified the thiocarbonyl moiety of 6MP or 6TG as the active pharmacophore essential for these inhibitions, which has not been reported before. The inhibition is selective because these compounds do not exert significant inhibitory effects against other cysteine proteases, including SARS-CoV 3CLpro and several cathepsins. Thus, our results present the first potential chemical leads against SARS-CoV PLpro, which might be used as lead compounds for further optimization to enhance their potency against SARS-CoV. Both 6MP and 6TG are still used extensively in clinics, especially for children with acute lymphoblastic or myeloblastic leukemia. In light of the possible inhibition against subset of cysteine proteases, our study has emphasized the importance to study in depth these drug actions in vivo.     

Preparation and development of equine hyperimmune globulin F（ab^1）2 against severe acute respiratory syndrome coronavirus

AIM: The resurgence of severe acute respiratory syndrome (SARS) is still a threat because the causative agent remaining in animal reservoirs is not fully understood, and sporadic cases continue to be reported. Developing high titers of anti-SARS hyperimmune globulin to provide an alternative pathway for emergent future prevention and treatment of SARS. METHODS: SARS coronavirus (CoV)F69 (AY313906) and Z2-Y3 (AY394989) were isolated and identified from 2 different Cantonese onset SARS patients. Immunogen was prepared from SARS-CoV F69 strain. Six health horses were immunized 4 times and serum was collected periodically to measure the profile of specific IgG and neutralizing antibodies using indirect enzyme-linked immunosorbent assay and a microneutralization test. Sera were collected in large amounts at the peak, where IgG was precipitated using ammonium sulphate and subsequently digested with pepsin. The product was then purified using anion-exchange chromatography to obtain F(ab')2 fragments. RESULTS: The specific IgG and neutralizing antibody titers peaked at approximately week 7 after the first immunization, with a maximum value of 1:14210. The sera collected at the peak were then purified. Fragment of approximately 15 g F(ab')2 was obtained from 1litre antiserum and the purity was above 90% with the titer of 1:5120, which could neutralize the other strain (SARS-CoV Z2-Y3) as well. CONCLUSION: This research provides a viable strategy for the prevention and treatment of SARS coronavirus infection with equine hyperimmune globulin, with the purpose of combating any resurgence of SARS.     

Recent developments in the virology and antiviral research of severe acute respiratory syndrome coronavirus

This article summarizes the significant developments and new discoveries in both the virology and antiviral research associated with the severe acute respiratory syndrome coronavirus (SARS CoV) that were reported in 2005 and 2006. Areas reviewed include genomic studies and the identification of bat-SARS CoV, spike protein and host cell entry, nucleocapsid protein, accessory proteins, non-structural proteins of the replicase complex, viral proteases and their inhibitors, and clinical treatment of SARS with ribavirin.     

重症急性呼吸综合征22例临床特点及综合防治方法

目的 探讨重症急性呼吸综合征(SARS)的临床特点和综合防治方法。方法 对2003年2月至5月我院收治的22例SARS病人的临床表现、X线特征、实验室资料、综合防治方法等进行分析。结果 发病2周内有密切接触SARS病人的16例；宰杀过动物的2例；潜伏期3～12d。所有病人均以发热为首发症状，其中有高热(39℃)以上者占91％。伴呼吸困难的68％，咳嗽86，4％，乏力72．7％．全身酸痛27％，头痛50％，头晕22．7％，胸痛31．8％，呼吸道卡他症状13．6％．心悸36．4％，腹泻18．2％，血丝痰9％，畏寒18．2％，咽痛9％。77％的病人肺部无明显体征。X线胸片及肺部CT：单侧病灶36．4％，双侧63．6％，双肺弥漫性渗出22．7％。ARDS2例；死亡1例。死亡率4．5％。规律应用皮质类固醇治疗的占72．7％。应用无创正压通气(NIPPV)的5例；应用有创机械通气的2例。通过规范的防护措施，一线医务人员感染率为零；医务人员家属感染率为零；院内交叉感染率为零。结论 综合治疗方案中，合理应用糖皮质激素是重要措施。重症病人应及早使用机械通气。规范的防护措施可预防感染。     

严重急性呼吸综合征冠状病毒特异转移因子的制备及其免疫活性研究

目的制备严重急性呼吸综合征 (SARS)冠状病毒特异转移因子并探讨其免疫学活性。方法以灭活的SARS冠状病毒免疫健康猪 ,取免疫后猪的脾脏和淋巴结 ,透析法提取转移因子 ,并作相应检测。通过巨噬细胞吞噬功能试验和白细胞黏附抑制试验探讨该品的免疫学活性。结果各项检测合格。巨噬细胞吞噬功能试验证明该品能促进巨噬细胞吞噬功跑。白细胞黏附抑制试验显示该品能提高未黏附白细胞抑制指数。结论SARS冠状病毒特异转移因子具有免疫增强作用和特异的免疫活性。     

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19): The epidemic and the challenges

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; previously provisionally named 2019 novel coronavirus or 2019-nCoV) disease (COVID-19) in China at the end of 2019 has caused a large global outbreak and is a major public health issue. As of 11 February 2020, data from the World Health Organization (WHO) have shown that more than 43 000 confirmed cases have been identified in 28 countries/regions, with >99% of cases being detected in China. On 30 January 2020, the WHO declared COVID-19 as the sixth public health emergency of international concern. SARS-CoV-2 is closely related to two bat-derived severe acute respiratory syndrome-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21. It is spread by human-to-human transmission via droplets or direct contact, and infection has been estimated to have mean incubation period of 6.4 days and a basic reproduction number of 2.24–3.58. Among patients with pneumonia caused by SARS-CoV-2 (novel coronavirus pneumonia or Wuhan pneumonia), fever was the most common symptom, followed by cough. Bilateral lung involvement with ground-glass opacity was the most common finding from computed tomography images of the chest. The one case of SARS-CoV-2 pneumonia in the USA is responding well to remdesivir, which is now undergoing a clinical trial in China. Currently, controlling infection to prevent the spread of SARS-CoV-2 is the primary intervention being used. However, public health authorities should keep monitoring the situation closely, as the more we can learn about this novel virus and its associated outbreak, the better we can respond.     

Specific plant terpenoids and lignoids possess potent antiviral activities against severe acute respiratory syndrome coronavirus

In this study, 221 phytocompounds were evaluated for activity against anti-severe acute respiratory syndrome associated coronavirus (SARS-CoV) activities using a cell-based assay measuring SARS-CoV-induced cytopathogenic effect on Vero E6 cells. Ten diterpenoids (1-10), two sesquiterpenoids (11 and 12), two triterpenoids (13 and 14), five lignoids (15-19), curcumin (20), and reference controls niclosamide (21) and valinomycin (22) were potent inhibitors at concentrations between 3.3 and 10 microM. The concentrations of the 22 compounds to inhibit 50% of Vero E6 cell proliferation (CC50) and viral replication (EC50) were measured. The selective index values (SI = CC50/EC50) of the most potent compounds 1, 5, 6, 8, 14, and 16 were 58, >510, 111, 193, 180, and >667, respectively. Betulinic acid (13) and savinin (16) were competitive inhibitors of SARS-CoV 3CL protease with Ki values = 8.2 +/- 0.7 and 9.1 +/- 2.4 microM, respectively. Our findings suggest that specific abietane-type diterpenoids and lignoids exhibit strong anti-SARS-CoV effects.     

新型冠状病毒的起源追溯与探讨

本文以2019年末在武汉发生的新型冠状病毒疫情为背景,探讨了冠状病毒家族与严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)的来源,阐述了病毒与具有免疫系统的长期宿主的共存机制,在免疫压力下长驻病毒群的演化机制,跨物种演化与病毒家族的形成,常驻病毒群和外源病毒群与疾病的关系和致病机制;指出了SARS-CoV-2当属人类冠状病毒的突变株而非源于蝙蝠经多重变异的冠状病毒。因不同的病毒来源对人类有着不同的感染机制、流行规律、致病机制、以及随之相应的临床转归与防治措施。明确SARS-CoV-2的来源对病毒性疫情防治有重大指导意义。