Tumour necrosis factor-alpha augments the expression of Fc IgE receptor (Fc epsilon RII/CD23) on human monocytic cell lines and down-regulates interleukin-4-driven Fc epsilon RII expression on monocytes.
We investigated the expression of the low affinity Fc IgE receptor (Fc epsilon RII/CD23) on the human monocytic cell lines U937, THP-1, Mono-Mac-6, and cultured human peripheral blood monocytes under stimulation with human tumour necrosis factor-alpha (TNF-alpha) and other cytokines. Fc epsilon RII was demonstrated by flow cytometry analysis employing the anti-Fc epsilon RII monoclonal antibody 3-5. TNF-alpha alone had a weak but significant stimulating effect on the Fc epsilon RII expression on the cell lines U937 and THP-1, and very modestly on Mono-Mac-6 cells. TNF-alpha strongly synergized with interferon-gamma (IFN-gamma) and interleukin-4 (IL-4). IFN-alpha per se was ineffectual, but was able to increase the TNF-alpha effect. Furthermore, the action of TNF-alpha was slightly augmented by human IL-6. Similar effects were noted with TNF-beta alone or in combination with other cytokines. Interestingly, on human monocytes TNF-alpha weakly reduced the basal level of Fc epsilon RII, and markedly diminished the IL-4-induced Fc epsilon RII expression. Our results indicate that several cytokines may interact in a cytokine network to modulate Fc epsilon RII expression on monocytic cell lines. On human blood monocytes, TNF-alpha, like IFN-gamma or IL-6, counteracts the IL-4-induced Fc epsilon RII expression. These data suggest different regulatory pathways of Fc epsilon RII expression on blood monocytes and myelomonocytic cell lines.
Gessl
A
A
Institute of General and Experimental Pathology, Vienna University School of Medicine, Austria.
Willheim
M
M
Agis
H
H
Spittler
A
A
Schedle
A
A
Krugluger
W
W
Förster
O
O
Boltz-Nitulescu
G
G
D002460:Cell Line; D006801:Humans; D007370:Interferon Type I / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology*; D015850:Interleukin-6 / Q000276:immunology; D007700:Kinetics; D008233:Lymphotoxin-alpha / Q000276:immunology; D009000:Monocytes / Q000276:immunology*; D017455:Receptors, IgE / Q000032:analysis*; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D007370:Interferon Type I; D015850:Interleukin-6; D008233:Lymphotoxin-alpha; D017455:Receptors, IgE; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007371:Interferon-gamma