Enhanced monocyte Fc phagocytosis by a homologue of interleukin-10 encoded by human cytomegalovirus.
Human cytomegalovirus (HCMV) expresses several homologues of human interleukin 10 (hIL-10) possessing immunomodulatory properties which may promote viral infection by modulating the function of myeloid cells. We examined the phenotype and phagocytic capability of human monocytes exposed to hIL-10, an HCMV-encoded hIL-10 homologue expressed during the productive phase of infection (cmvIL-10), and a differentially spliced form of cmvIL-10 expressed during latent and productive phases of infection, (LAcmvIL-10). hIL-10 and cmvIL-10 upregulated expression of Fcgamma receptors, stimulated phagocytosis of IgG-opsonised erythrocytes and decreased MHC class II (HLA-DR) expression on purified monocytes within 24 h. In contrast, LAcmvIL-10 decreased HLA-DR expression at later times (48 h and 72 h) but did not increase Fcgamma receptor expression. We conclude that cmvIL-10 promotes differentiation of monocytes towards a pro-phagocytic phenotype and that LAcmvIL-10 does not affect monocytes by the same mechanism as cmvIL-10. The significance of these properties to cytomegalovirus pathogenesis is discussed.
Jaworowski
Anthony
A
Centre for Virology, Macfarlane Burnet Institute for Public Health and Medical Research, Melbourne 3004, Australia. anthonyj@burnet.edu.au
Cheng
Wan-Jung
WJ
Westhorpe
Clare L
CL
Abendroth
Allison
A
Crowe
Suzanne M
SM
Slobedman
Barry
B
D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000821:virology; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology*; D009000:Monocytes / Q000276:immunology* / Q000821:virology; D010587:Phagocytosis / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology / Q000378:metabolism; D014764:Viral Proteins / Q000276:immunology* / Q000378:metabolism
C405505:IL-10 like protein, Human herpesvirus 5; D017452:Receptors, IgG; D014764:Viral Proteins; D016753:Interleukin-10