IL-2R, IL-4R, and IL-7R share a common subunit referred to as γc and the IL-13R has been proposed to contain γc as a subunit. In this report we have used two novel mAbs (3E12 and 4G3) to distinct epitopes of mouse γc to determine its lymphoid cell distribution and to examine whether γc uses similar epitopes to interact with different cytokines and cytokine receptors. FACS analysis revealed that γc is expressed in most lymphocytes, myeloid cells, embryonic thymocytes, and lymphoid cell lines. Results from radiolabeled ligand binding studies, biochemical analysis of ligand-receptor cross-linked complexes, and cytokine bioassays indicate that the epitope defined by mAb 4G3 closely defines the IL-7 binding region of γc and overlaps the IL-2 binding region of γc. These studies also indicate that γc interacts with IL-4 in the context of the IL-4R in a manner that is distinct from its role in the IL-2R and IL-7R and suggest that the 3E12 epitope defines a region of γc that intimately interacts with the IL-4R. The B9 plasmacytoma, which proliferates in response to IL-4 and IL-13, was shown to not express γc. Thus, at least in some circumstances, γc is dispensable for signaling via the IL-4R and is not a required subunit of the IL-13R.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1995|
ASJC Scopus subject areas
- Immunology and Allergy