IL-27, a novel anti-HIV cytokine, activates multiple interferon-inducible genes in macrophages.
OBJECTIVE
IL-27 is a novel anti-HIV cytokine that inhibits HIV-1 replication in both CD4 T cells and monocyte-derived macrophages (MDM) as IFN-alpha does. To elucidate the mechanism of the antiviral activity, we compared the activity and the gene expression profile of IL-27-treated cells with that of IFN-alpha-treated cells.


METHODS
CD4 T cells and monocytes were isolated from peripheral blood mononuclear cells of healthy donors. CD4 T cells were stimulated with phytohemagglutinin, and MDM were induced from monocytes using macrophage-colony stimulating factor. HIV-1 replication was monitored by p24 antigen capture assay. The gene expression profiles were analysed using DNA microarray analysis. The increase in the expression of IFN-inducible genes (IFIG) was confirmed by the Quantigene plex assay.


RESULTS
Both cytokines preferentially inhibited HIV-1 replication in MDM compared with CD4 T cells. Quantitative real time polymerase chain reaction, enzyme-linked immunosorbent assay and neutralization assay using anti-IFN indicated that IFN-alpha, IFN-beta and IFN-gamma had no significant impact on IL-27-mediated HIV inhibition. DNA microarray analysis illustrated that IFN-alpha induced 33 and 18 IFIG in MDM and CD4 T cells, respectively. IL-27 induced 28 IFIG in MDM and five IFIG in CD4 T cells. The quantitative assay confirmed that IL-27 activated genes of RNA-dependent kinase, oligoadenylate synthetase, myxovirus protein, and apolipoprotein B messenger RNA-editing enzyme-catalytic polypeptide-like 3G.


CONCLUSIONS
IL-27 differentially regulates the gene expression between CD4 T cells and MDM. IL-27 significantly induces antiviral genes in MDM as does IFN-alpha, suggesting that IL-27 inhibits HIV replication in MDM via mechanism(s) similar to that of IFN-alpha.
Imamichi
Tomozumi
T
Laboratory of Human Retrovirology, National Cancer Institute at Frederick, Frederick, Maryland, USA. timamichi@mail.nih.gov
Yang
Jun
J
Huang
Da-Wei
DW
Brann
Terrence W
TW
Fullmer
Brandie A
BA
Adelsberger
Joseph W
JW
Lempicki
Richard A
RA
Baseler
Michael W
MW
Lane
H Clifford
HC
D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000821:virology; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral / Q000235:genetics; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D016898:Interferon-alpha / Q000494:pharmacology; D007378:Interleukins / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism / Q000821:virology; D020411:Oligonucleotide Array Sequence Analysis; D014779:Virus Replication / Q000276:immunology
D017077:Culture Media, Conditioned; D016898:Interferon-alpha; D007378:Interleukins; C464565:MYDGF protein, human