The gamma subunit of the interleukin-2 receptor is expressed in human monocytes and modulated by interleukin-2, interferon gamma, and transforming growth factor beta 1.
The interleukin-2 receptor gamma (IL-2R gamma) chain is a newly recognized component of the IL-2R of lymphoid cells that is required for their response to IL-2. We investigated the expression of IL-2R gamma protein in human monocytes by Western blot analysis using an antiserum specific for IL-2R gamma. We found that IL-2R gamma subunit is constitutively expressed in human monocytes and upregulated by the monocyte-activating factors IL-2 and interferon gamma (IFN gamma). Furthermore, we show that transforming growth factor beta 1 (TGF beta 1) downmodulates, in a dose-dependent manner, basal and IL-2-induced, but not IFN gamma-induced, IL-2R gamma chain expression, and this effect may be responsible for TGF beta 1 suppressive activity on IL-2-activated monocytes. Overall, these results show that the expression of the IL-2R gamma subunit in human monocytes is tightly regulated by the cytokine network, suggesting a critical role played by this protein on monocyte activation.
Bosco
M C
MC
Laboratory of Experimental Immunology, National Cancer Institute-Frederick Cancer Research and Development Center, MD 21702-1201.
Espinoza-Delgado
I
I
Schwabe
M
M
Russell
S M
SM
Leonard
W J
WJ
Longo
D L
DL
Varesio
L
L
D004305:Dose-Response Relationship, Drug; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007376:Interleukin-2 / Q000494:pharmacology*; D009000:Monocytes / Q000737:chemistry*; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D016212:Transforming Growth Factor beta; D007371:Interferon-gamma