Link of a ubiquitous human coronavirus to dromedary camels
2016; National Academy of Sciences; Volume: 113; Issue: 35 Linguagem: Inglês
10.1073/pnas.1604472113
ISSN1091-6490
AutoresVictor M. Corman, Isabella Eckerle, Ziad A. Memish, Anne Liljander, Ronald Dijkman, Hulda R. Jónsdóttir, Kisi J. Z. Juma Ngeiywa, Esther Kamau, M. Younan, Malakita Al Masri, Abdullah M. Assiri, Ilona Gluecks, Bakri E. Musa, Benjamin Meyer, Marcel A. Müller, M. Hilali, Set Bornstein, U. Wernery, Volker Thiel, Joerg Jores, Jan Felix Drexler, Christian Drosten,
Tópico(s)Viral gastroenteritis research and epidemiology
ResumoThe 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.
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