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

Publisher Website
Google Scholar
Abstract
Functional 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 only the 64-kDa IL-2Rγ protein band in monocytes.