Differential effects of IFN-alpha on the expression of various TH2 cytokines in human CD4+ T cells.
BACKGROUND
In both human subjects and mice, T helper cells are classified into 2 subsets, TH1 and TH2 cells, on the basis of the cytokines they produce. Although IFN-alpha has been shown to enhance human TH1 responses, its influences on human TH2 responses have not yet been fully characterized. In addition, the mechanism for induction of TH1 responses by IFN-alpha has not been fully delineated.


OBJECTIVE
The present study was undertaken to explore the direct effects of IFN-alpha on the expression of various cytokines in human CD4+ T cells with a system using immobilized anti-CD3, which permits activation of CD4+ T cells in the complete absence of accessory cells.


METHODS
Highly purified CD4+ T cells obtained from healthy donors were stimulated with immobilized anti-CD3 with or without IFN-alpha and IL-12 in the complete absence of accessory cells. The production of cytokines was estimated by means of ELISA. The expression of mRNA for various cytokines, as well as transcription factors, was evaluated by using quantitative PCR.


RESULTS
IFN-alpha enhanced IL-4 protein and mRNA expression in immobilized anti-CD3-stimulated CD4+ T cells, irrespective of the presence of IL-12, whereas IFN-alpha suppressed the expression of IL-5 and IL-13. Of note, IFN-alpha enhanced the expression of mRNA for c-Maf, T-bet, and Fox-P3, irrespective of the presence of IL-12, but not that for GATA-3, in anti-CD3-stimulated CD4+ T cells.


CONCLUSIONS
These results indicate that IFN-alpha enhances the induction of TH1 responses through upregulation of T-bet mRNA expression, as well as the induction of TH2 responses through upregulation of c-Maf mRNA expression, followed by IL-4 expression. Moreover, the data also suggest that IFN-alpha might suppress the expression of IL-5 and IL-13 in differentiated TH2 cells.
Shibuya
Hideki
H
Department of Internal Medicine, Teikyo University School of Medicine, Japan.
Hirohata
Shunsei
S
D015704:CD4 Antigens / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis* / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D051858:Forkhead Transcription Factors; D006801:Humans; D016898:Interferon-alpha / Q000276:immunology* / Q000378:metabolism; D018664:Interleukin-12 / Q000096:biosynthesis / Q000276:immunology; D018793:Interleukin-13 / Q000096:biosynthesis / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis / Q000276:immunology; D015848:Interleukin-5 / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000276:immunology; D051257:Proto-Oncogene Proteins c-maf; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020825:T-Box Domain Proteins; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis / Q000276:immunology; D000098815:T-bet Transcription Factor
D015704:CD4 Antigens; D016207:Cytokines; D004268:DNA-Binding Proteins; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D016898:Interferon-alpha; D018793:Interleukin-13; D015848:Interleukin-5; C495607:MAF protein, human; D011518:Proto-Oncogene Proteins; D051257:Proto-Oncogene Proteins c-maf; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D014157:Transcription Factors; D018664:Interleukin-12; D015847:Interleukin-4