SARS-coronavirus replication in human peripheral monocytes/macrophages.
A novel coronavirus (CoV) has been described in association with cases of severe acute respiratory syndrome (SARS). The virus, SARS-CoV, differs from the previously described human coronaviruses, 229E and OC43. 229E was previously shown to productively infect human monocytes/macrophages, whereas OC43 poorly infected the cells. In this study, we examined whether SARS-CoV could productively infect purified monocytes/macrophages (PM) derived from human donor cells. Unlike 229E-infected cells, which produced viral titers of 10(3.5) to 10(6)TCID50/ml, SARS-CoV replicated poorly in PM, producing titers of 10(1.75) to 10(2)TCID50/ml. This finding was similar to results reported for OC43-infected cells, with titers ranging from 10(1.2) to 10(2.7)TCID50/ml. Of interest, SARS-CoV proteins were detected only in PM that did not produce significant amounts of interferon (IFN)-alpha, and in one such case, preliminary electron microscope studies demonstrated that SARS-CoV-like particles could enter the cells, possibly via phagocytosis. These results suggest that SARS-CoV, like human CoV OC43, poorly infects human PM, and production of IFN-alpha by these cells further limits the infection. Given the importance of monocytes/macrophages to the immune response, it is possible that their infection by SARS-CoV and alteration of this infection by IFN-alpha may be important to the course of the infection in humans.
Yilla
Mamadi
M
Respiratory and Enteric Viruses Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd., MS-C22, Atlanta, GA 30333, USA. mby7@cdc.gov
Harcourt
Brian H
BH
Hickman
Carole J
CJ
McGrew
Marcia
M
Tamin
Azaibi
A
Goldsmith
Cynthia S
CS
Bellini
William J
WJ
Anderson
Larry J
LJ
D000328:Adult; D000914:Antibodies, Viral; D006801:Humans; D066298:In Vitro Techniques; D016898:Interferon-alpha / Q000096:biosynthesis; D008264:Macrophages / Q000648:ultrastructure / Q000821:virology*; D008854:Microscopy, Electron; D009000:Monocytes / Q000648:ultrastructure / Q000821:virology*; D010587:Phagocytosis; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D045169:Severe Acute Respiratory Syndrome / Q000821:virology; D014779:Virus Replication
D000914:Antibodies, Viral; D016898:Interferon-alpha