Expression of interleukin‐2 receptor γ on human monocytes: characterization of lineage specific post‐translational modifications

摘要

AbstractFunctional interleukin‐2 receptors (IL‐2R) on lymphocytes contain both IL‐2R β and γ chains. Whereas constitutive expression of IL‐2Rβ has been found on monocytes, the expression of IL‐2Rγ on these phagocytes has not been examined. We performed reverse‐transcription‐polymerase chain reaction with Southern blot analysis on RNA derived from purified human monocytes and discovered that they constitutively produce IL‐2Rγ mRNA. Western immunoblotting revealed 58‐and 64‐kDa forms of IL‐2Rγ on YT‐1 and human monocytes, whereas 58‐, 64‐, and 69‐kDa bands were detected using peripheral blood mononuclear cells and non‐adherent lymphocytes. These different forms resulted from variable N‐linked glycosylation since culture of the cells in tunicamycin resulted in detection of a single 39‐kDa band which corresponds to the molecular weight predicted from the deduced amino acid sequence. By co‐immunoprecipitation, the IL‐2Rβ subunit associates with on