Interleukin-2 receptor subunit beta is a type I membrane protein that in humans is encoded by the CD122 gene, also known as IL2RB, IL15RB and P70-75. The interleukin 2 receptor, which is involved in T cell-mediated immune responses, is present in 3 forms with respect to ability to bind interleukin 2. The low affinity form is a monomer of the alpha subunit (also called CD25) and is not involved in signal transduction. The intermediate affinity form consists of a gamma/beta subunit heterodimer, while the high affinity form consists of an alpha/beta/gamma subunit heterotrimer. Both the intermediate and high affinity forms of the receptor are involved in receptor-mediated endocytosis and transduction of mitogenic signals from interleukin 2. IL2RB also forms one of the three subunits of the IL-15 receptor, and mainly expressed on CD4+ T cell, CD8+ T cell, Treg, NK cell, the activation of the receptor increases proliferation of CD8+ effector T cells.
Protein expression analysis
Strain specific IL2RB expression analysis in heterozygous B-hIL2RB mice by flow cytometry. Splenocytes were collected from WT and heterozygous B-hIL2RB (H/+) mice stimulated with anti-CD3ε in vivo, and analyzed by flow cytometry with species-specific anti-IL2RB antibody. Mouse IL2RB was detectable in WT and heterozygous B-hIL2RB mice. Human IL2RB was exclusively detectable in heterozygous B-hIL2RB but not WT mice.