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Abstract
PURPOSE OF REVIEW An international outbreak of severe acute respiratory syndrome, a recently recognized syndrome caused by the newly identified severe acute respiratory syndrome-associated coronavirus, began in November 2002 and ended in July 2003. Since then, a large body of research on the syndrome has been published; the most updated developments are summarized here. RECENT FINDINGS Recent findings suggest that animal severe acute respiratory syndrome-like coronaviruses may have been transmitted to humans without detection for years before the recent outbreak, and that such transmission may be continuing today. The 2002-2003 outbreak probably originated from similar animal-to-human transmission, but selection and purification of the animal severe acute respiratory syndrome-like virus appears to have occurred, creating the more virulent severe acute respiratory syndrome-associated coronavirus. Recent studies have documented that severe acute respiratory syndrome-associated coronavirus is primarily transmitted via contact and/or respiratory droplets and that the combination of standard, contact, and droplet precautions is generally effective for its control. It has been shown that severe acute respiratory syndrome-associated coronavirus is typically relatively inefficiently transmitted, with the notable exception of transmission during superspreading events. Insights into the pathogenesis of severe acute respiratory syndrome have been made: one study suggests that human leukocyte antigen HLA-B*4601 is a possible risk factor for more severe disease, while another identifies angiotensin-converting enzyme 2 as a cellular receptor for severe acute respiratory syndrome-associated coronavirus. Promising treatments have been identified, including interferons, an anti-spike monoclonal antibody, and fusion inhibitors. In addition, many promising vaccines are currently in development. SUMMARY New findings regarding severe acute respiratory syndrome are continuing to be discovered at an unprecedented pace, permitting a better understanding of the disease and enabling better preparation for its possible return.
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Affiliation(s)
- Susan M Poutanen
- Toronto Medical Laboratories and Mount Sinai Hospital Department of Microbiology, Toronto, Ontario, Canada
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403
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Xu Y, Lou Z, Liu Y, Pang H, Tien P, Gao GF, Rao Z. Crystal structure of severe acute respiratory syndrome coronavirus spike protein fusion core. J Biol Chem 2004; 279:49414-9. [PMID: 15345712 PMCID: PMC8008698 DOI: 10.1074/jbc.m408782200] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus is a newly emergent virus responsible for a recent outbreak of an atypical pneumonia. The coronavirus spike protein, an enveloped glycoprotein essential for viral entry, belongs to the class I fusion proteins and is characterized by the presence of two heptad repeat (HR) regions, HR1 and HR2. These two regions are understood to form a fusion-active conformation similar to those of other typical viral fusion proteins. This hairpin structure likely juxtaposes the viral and cellular membranes, thus facilitating membrane fusion and subsequent viral entry. The fusion core protein of severe acute respiratory syndrome coronavirus spike protein was crystallized, and the structure was determined at 2.8 A of resolution. The fusion core is a six-helix bundle with three HR2 helices packed against the hydrophobic grooves on the surface of central coiled coil formed by three parallel HR1 helices in an oblique antiparallel manner. This structure shares significant similarity with the fusion core structure of mouse hepatitis virus spike protein and other viral fusion proteins, suggesting a conserved mechanism of membrane fusion. Drug discovery strategies aimed at inhibiting viral entry by blocking hairpin formation, which have been successfully used in human immunodeficiency virus 1 inhibitor development, may be applicable to the inhibition of severe acute respiratory syndrome coronavirus on the basis of structural information provided here. The relatively deep grooves on the surface of the central coiled coil will be a good target site for the design of viral fusion inhibitors.
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Affiliation(s)
- Yanhui Xu
- Laboratory of Structural Biology, Tsinghua University, Beijing 100084 and National Laboratory of Bio-Macromolecules, Institute of Biophysics, Beijing 100101, China
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404
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Abstract
The worldwide epidemic of severe acute respiratory syndrome (SARS) in 2003 was caused by a novel coronavirus called SARS-CoV. Coronaviruses and their closest relatives possess extremely large plus-strand RNA genomes and employ unique mechanisms and enzymes in RNA synthesis that separate them from all other RNA viruses. The SARS epidemic prompted a variety of studies on multiple aspects of the coronavirus replication cycle, yielding both rapid identification of the entry mechanisms of SARS-CoV into host cells and valuable structural and functional information on SARS-CoV proteins. These recent advances in coronavirus research have important implications for the development of anti-SARS drugs and vaccines.
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Key Words
- 2′-o-mt, 2′-o-ribose methyltransferase
- 3clpro, 3c-like main protease
- adrp, adp-ribose 1″-phosphatase
- cpd, cyclic phosphodiesterase
- exon, 3′-to-5′ exoribonuclease
- hcov-229e, human coronavirus 229e
- hr, heptad repeat
- nendou, nidoviral uridylate-specific endoribonuclease
- orf, open reading frame
- pl2pro, papain-like protease 2
- rdrp, rna-dependent rna polymerase
- sars, severe acute respiratory syndrome
- sars-cov, severe acute respiratory syndrome coronavirus
- sg mrna, subgenomic mrna
- trs, transcription-regulating sequence
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Affiliation(s)
- John Ziebuhr
- Institute of Virology and Immunology, University of Würzburg, Versbacher Str. 7, 97078 Würzburg, Germany.
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405
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Yuan K, Yi L, Chen J, Qu X, Qing T, Rao X, Jiang P, Hu J, Xiong Z, Nie Y, Shi X, Wang W, Ling C, Yin X, Fan K, Lai L, Ding M, Deng H. Suppression of SARS-CoV entry by peptides corresponding to heptad regions on spike glycoprotein. Biochem Biophys Res Commun 2004; 319:746-52. [PMID: 15184046 PMCID: PMC7111000 DOI: 10.1016/j.bbrc.2004.05.046] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2004] [Indexed: 12/30/2022]
Abstract
Heptad repeat regions (HR1 and HR2) are highly conserved sequences located in the glycoproteins of enveloped viruses. They form a six-helix bundle structure and are important in the process of virus fusion. Peptides derived from the HR regions of some viruses have been shown to inhibit the entry of these viruses. SARS-CoV was also predicted to have HR1 and HR2 regions in the S2 protein. Based on this prediction, we designed 25 peptides and screened them using a HIV-luc/SARS pseudotyped virus assay. Two peptides, HR1-1 and HR2-18, were identified as potential inhibitors, with EC50 values of 0.14 and 1.19 μM, respectively. The inhibitory effects of these peptides were validated by the wild-type SARS-CoV assay. HR1-1 and HR2-18 can serve as functional probes for dissecting the fusion mechanism of SARS-CoV and also provide the potential of further identifying potent inhibitors for SARS-CoV entry.
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Affiliation(s)
- Kehu Yuan
- Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing 100871, PR China
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406
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Ding Y, He L, Zhang Q, Huang Z, Che X, Hou J, Wang H, Shen H, Qiu L, Li Z, Geng J, Cai J, Han H, Li X, Kang W, Weng D, Liang P, Jiang S. Organ distribution of severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) in SARS patients: implications for pathogenesis and virus transmission pathways. J Pathol 2004; 203:622-30. [PMID: 15141376 PMCID: PMC7167761 DOI: 10.1002/path.1560] [Citation(s) in RCA: 766] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously identified the major pathological changes in the respiratory and immune systems of patients who died of severe acute respiratory syndrome (SARS) but gained little information on the organ distribution of SARS‐associated coronavirus (SARS‐CoV). In the present study, we used a murine monoclonal antibody specific for SARS‐CoV nucleoprotein, and probes specific for a SARS‐CoV RNA polymerase gene fragment, for immunohistochemistry and in situ hybridization, respectively, to detect SARS‐CoV systematically in tissues from patients who died of SARS. SARS‐CoV was found in lung, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum, but was not detected in oesophagus, spleen, lymph node, bone marrow, heart, aorta, cerebellum, thyroid, testis, ovary, uterus or muscle. These results suggest that, in addition to the respiratory system, the gastrointestinal tract and other organs with detectable SARS‐CoV may also be targets of SARS‐CoV infection. The pathological changes in these organs may be caused directly by the cytopathic effect mediated by local replication of the SARS‐CoV; or indirectly as a result of systemic responses to respiratory failure or the harmful immune response induced by viral infection. In addition to viral spread through a respiratory route, SARS‐CoV in the intestinal tract, kidney and sweat glands may be excreted via faeces, urine and sweat, thereby leading to virus transmission. This study provides important information for understanding the pathogenesis of SARS‐CoV infection and sheds light on possible virus transmission pathways. This data will be useful for designing new strategies for prevention and treatment of SARS. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Yanqing Ding
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Li He
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Qingling Zhang
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Zhongxi Huang
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Xiaoyan Che
- Department of Infectious Diseases, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Jinlin Hou
- Centre Laboratory, Zhujiang Hospital, First Military Medical University, Guangzhou, China
| | - Huijun Wang
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Hong Shen
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Liwen Qiu
- Centre Laboratory, Zhujiang Hospital, First Military Medical University, Guangzhou, China
| | - Zhuguo Li
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Jian Geng
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Junjie Cai
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Huixia Han
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Xin Li
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Wei Kang
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Desheng Weng
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Ping Liang
- Department of Pathology, Nan Fang Hospital, First Military Medical University, Guangzhou, China
| | - Shibo Jiang
- Laboratory of Viral Immunology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, USA
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407
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Ingallinella P, Bianchi E, Finotto M, Cantoni G, Eckert DM, Supekar VM, Bruckmann C, Carfi A, Pessi A. Structural characterization of the fusion-active complex of severe acute respiratory syndrome (SARS) coronavirus. Proc Natl Acad Sci U S A 2004; 101:8709-14. [PMID: 15161975 PMCID: PMC423260 DOI: 10.1073/pnas.0402753101] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Indexed: 11/18/2022] Open
Abstract
The causative agent of a recent outbreak of an atypical pneumonia, known as severe acute respiratory syndrome (SARS), has been identified as a coronavirus (CoV) not belonging to any of the previously identified groups. Fusion of coronaviruses with the host cell is mediated by the envelope spike protein. Two regions within the spike protein of SARS-CoV have been identified, showing a high degree of sequence conservation with the other CoV, which are characterized by the presence of heptad repeats (HR1 and HR2). By using synthetic and recombinant peptides corresponding to the HR1 and HR2 regions, we were able to characterize the fusion-active complex formed by this novel CoV by CD, native PAGE, proteolysis protection analysis, and size-exclusion chromatography. HR1 and HR2 of SARS-CoV associate into an antiparallel six-helix bundle, with structural features typical of the other known class I fusion proteins. We have also mapped the specific boundaries of the region, within the longer HR1 domain, making contact with the shorter HR2 domain. Notably, the inner HR1 coiled coil is a stable alpha-helical domain even in the absence of interaction with the HR2 region. Inhibitors binding to HR regions of fusion proteins have been shown to be efficacious against many viruses, notably HIV. Our results may help in the design of anti-SARS therapeutics.
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Affiliation(s)
- Paolo Ingallinella
- Istituto di Ricerche di Biologia Molecolare P. Angeletti, Via Pontina Km 30.600, 00040 Pomezia, Italy
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