Expression of interleukin-2 receptor gamma chain on human neutrophils

Abstract

The interleukin-2 (IL-2) receptor gamma is an indispensable functional component of IL-2, IL-4, and IL-7 receptors, and thus, is denoted the common gamma chain, gamma c. The present study was undertaken to determine whether human polymorphonuclear neutrophils (PMNs) expressed gamma c chain. Reverse transcription-polymerase chain reaction and Northern blot analysis showed that fresh human PMN constitutively expressed a remarkable level of gamma c mRNA, which is of the size and intensity of that from the peripheral blood mononuclear cells (PBMCs). Granulocyte macrophage-colony stimulating factor, IL-2, and IL-8, which are known to activate PMN functions, failed to regulate the gamma c gene expression. Western blot analysis with a rabbit anti-gamma c polyclonal antibody identified 64-, 58-, and 50-kD gamma c bands in lysates from PMN, but only 64- and 58-kD bands from PBMCs. After the PMNs and PBMCs were treated with tunicamycin to prevent N-linked glycosylation, Western blot analysis detected a single 39-kD band, which is equal to the calculated molecular weight from the cloned cDNA. Thus, our results indicate that PMNs constitutively express high levels of gamma c and the three forms detected are caused by different glycosylation of a protein translated from a single mRNA species.