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Proc Natl Acad Sci U S A. 2016 Aug 30;113(35):9864-9. doi: 10.1073/pnas.1604472113. Epub 2016 Aug 15.

Link of a ubiquitous human coronavirus to dromedary camels.

Author information

1
University of Bonn Medical Centre, 53127 Bonn, Germany; German Centre for Infection Research, partner site Bonn-Cologne, Germany;
2
University of Bonn Medical Centre, 53127 Bonn, Germany;
3
College of Medicine, Alfaisal University, 11533 Riyadh, Kingdom of Saudi Arabia;
4
International Livestock Research Institute, Nairobi, Kenya;
5
Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty Bern, University of Bern, 3012 Bern, Switzerland; Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhausern, Switzerland;
6
Ministry of Agriculture, Livestock, and Fisheries, State Department of Livestock, Department of Veterinary Services, Nairobi, Kenya;
7
Vétérinaires Sans Frontières Germany, Nairobi, Kenya;
8
Ministry of Health, 11176 Riyadh, Kingdom of Saudi Arabia;
9
Vétérinaires Sans Frontières Suisse, Nairobi, Kenya;
10
Ministry of Science and Communication, Khartoum, Sudan;
11
Cairo University, 12613 Giza, Egypt;
12
National Veterinary Institute, 75189 Uppsala, Sweden;
13
Central Veterinary Research Laboratory, Dubai, United Arab Emirates;
14
International Livestock Research Institute, Nairobi, Kenya; Institute of Veterinary Bacteriology, University of Bern, 3001 Bern, Switzerland.
15
University of Bonn Medical Centre, 53127 Bonn, Germany; German Centre for Infection Research, partner site Bonn-Cologne, Germany; drexler@virology-bonn.de drosten@virology-bonn.de.

Abstract

The four human coronaviruses (HCoVs) are globally endemic respiratory pathogens. The Middle East respiratory syndrome (MERS) coronavirus (CoV) is an emerging CoV with a known zoonotic source in dromedary camels. Little is known about the origins of endemic HCoVs. Studying these viruses' evolutionary history could provide important insight into CoV emergence. In tests of MERS-CoV-infected dromedaries, we found viruses related to an HCoV, known as HCoV-229E, in 5.6% of 1,033 animals. Human- and dromedary-derived viruses are each monophyletic, suggesting ecological isolation. One gene of dromedary viruses exists in two versions in camels, full length and deleted, whereas only the deleted version exists in humans. The deletion increased in size over a succession starting from camelid viruses via old human viruses to contemporary human viruses. Live isolates of dromedary 229E viruses were obtained and studied to assess human infection risks. The viruses used the human entry receptor aminopeptidase N and replicated in human hepatoma cells, suggesting a principal ability to cause human infections. However, inefficient replication in several mucosa-derived cell lines and airway epithelial cultures suggested lack of adaptation to the human host. Dromedary viruses were as sensitive to the human type I interferon response as HCoV-229E. Antibodies in human sera neutralized dromedary-derived viruses, suggesting population immunity against dromedary viruses. Although no current epidemic risk seems to emanate from these viruses, evolutionary inference suggests that the endemic human virus HCoV-229E may constitute a descendant of camelid-associated viruses. HCoV-229E evolution provides a scenario for MERS-CoV emergence.

KEYWORDS:

coronavirus; ecology; evolution; livestock; zoonotic diseases

PMID:
27528677
PMCID:
PMC5024591
DOI:
10.1073/pnas.1604472113
[Indexed for MEDLINE]
Free PMC Article

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