title: Contribution of monocytes to viral replication in macaques during acute infection with simian immunodeficiency virus.
abstract: Monocytes are known as an alternative target for HIV/SIV infection, but the contribution of monocytes to viral spread in a host is unclear. In this study, CD14 monocytes were monitored in 6 macaques until six weeks postinfection (wpi) with SIVmac239 to evaluate their contribution to viral load. The monocyte count in blood significantly increased with peak viremia at 2 wpi and the expression level of CD14 on monocytes significantly decreased at 1-2 wpi, though the number of CD4(+) T cells was stable in these macaques. The number of CD14 monocytes and the expression level of CD14 on monocytes at 2 wpi were also significantly related to the extent of viremia in plasma. An increased number of monocytes at 2 wpi was associated with a lower postacute viral load, suggesting that monocytes have a role in suppressing the virus. The lower expression level of CD14 in monocytes at 2 wpi was associated with a higher viral load and greater degree of infection of monocytes. This correlation suggests that monocytes with a low level of CD14 may be more susceptible to SIV and may enhance viral replication. The analysis of monocytes in persistently infected macaques revealed that the expression level of CD14 was also significantly low during persistent infection compared with naïve macaques, though the monocyte count was within the normal range. Monocytes may suppress viruses, perhaps by their immune function, during acute infection. However, infection of monocytes may increase the viral load and spread viruses in a host.
authors.affiliation: Laboratory of Primate Model, Experimental Research Center for Infectious Disease, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Kuwata
authors.forename: Makoto
authors.initials: M
authors.lastname: Kodama
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sato
authors.forename: Hajime
authors.initials: H
authors.lastname: Suzuki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Miura
authors.forename: Masanori
authors.initials: M
authors.lastname: Hayami
mesh_terms: D000818:Animals; D007958:Leukocyte Count / Q000145:classification; D018950:Lipopolysaccharide Receptors / Q000097:blood*; D008253:Macaca mulatta / Q000821:virology*; D009000:Monocytes / Q000145:classification / Q000166:cytology / Q000821:virology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000097:blood* / Q000503:physiopathology; D015302:Simian Immunodeficiency Virus / Q000472:pathogenicity*; D019562:Viral Load; D014766:Viremia; D014779:Virus Replication / Q000502:physiology*
chemical_list: D018950:Lipopolysaccharide Receptors