TY  - EJOU
AU  - Pillet, Anne-Hélène 
AU  - Juffroy, Olivier 
AU  - Mazard-Pasquier, Virginie 
AU  - Moreau, Jean-Louis 
AU  - Gesbert, Franck 
AU  - Chastagner, Patricia 
AU  - Colle, Jean-Hervé 
AU  - Thèze, Jacques 
AU  - Rose, Thierry 

TI  - Human IL-Rβ chains form IL-2 binding homodimers
T2  - European Cytokine Network

PY  - 2008
VL  - 19
IS  - 1
SN  - 1952-4005

AB  - Two types of functional interleukin-2 receptor (IL-2Rα/IL-2Rβ/γc and IL-2Rβ/γc) have already
been characterized in humans. Here we describe a new form consisting of IL-2Rβ/β homodimers that assemble
spontaneously in the absence of γc. Co-transfection of COS-7 cells with constructs expressing IL-2Rβ chains
tagged with either HA or MYC sequences results in the formation of IL-2Rβ:HA/IL-2Rβ:MYC complexes
detectable by coimmunoprecipitation. The formation of these IL-2Rβ:HA/IL-2Rβ:MYC dimers is also observed
in the absence of IL-2. Moreover, in COS cells expressing chimeras of IL-2Rβ fused to fluorescence reporters such
as IL-2Rβ:ECFP and IL-2Rβ:EYFP, we also observed specific FRET at the surface of living cells, as expected for
dimer formation. Transiently transfected COS-7 cells expressing IL-2Rβ bind 125
I-labeled IL-2 (homodimers,
Kd = 1nM) as cells expressing both IL-2Rβ and γc chains (heterodimers, Kd = 1 nM). IL-2Rβ/IL-2Rβ could
represent either a decoy receptor or a new form of IL-2R involved in signaling when γc expression is low.
KW  - interleukin-2
KW  -  IL-2R
KW  -  receptor assembly
KW  -  FRET

DO  - 10.1684/ecn.2008.0120