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Surface and Intracellular Interleukin‐2 Receptor Expression on Various Resting and Activated Populations Involved in Cell‐Mediated Immunity in Human Peripheral Blood
Author(s) -
Sandra Hodge,
Greg Hodge,
Robert L. Flower,
Ping Han
Publication year - 2000
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.2000.00644.x
Subject(s) - intracellular , receptor , biology , stimulation , monocyte , interleukin 12 , microbiology and biotechnology , interleukin 2 , immunology , cytotoxic t cell , in vitro , endocrinology , biochemistry
The kinetics of assembly of the high‐affinity interleukin‐2 receptor (IL‐2R)α/β/γ were investigated by studying intracellular and surface expression of IL‐2Rα, β and γ by T cells, monocytes and natural killer (NK) cells. IL‐2Rα and IL‐2Rγ were expressed by small numbers of resting T cells. These numbers increased following stimulation, to maximal expression at 48 h and 72 h, respectively. This observation was consistent with de novo synthesis of the receptor protein in response to the stimulus. The proportion of T cells producing IL‐2Rβ was smaller and up‐regulated later than the proportion of cells producing IL‐2Rα or IL‐2Rγ. IL‐2Rβ may therefore slow the assembly of the high‐affinity IL‐2R on T cells. A small number of resting NK cells expressed IL‐2Rα, both on the cell surface and intracellularly, but this increased over 72 h on stimulated NK cells. IL‐2Rβ was constitutively expressed, both on the cell surface and intracellularly, by monocytes and NK cells. An increased proportion of NK cells and monocytes produced IL‐2Rβ, 24 h and 4 h post‐stimulation, respectively. Maximal or plateau expression occurred at 72 h and 24 h post‐stimulation, for NK cells and monocytes, respectively. The early up‐regulation of intracellular IL‐2Rβ for monocytes may facilitate the up‐regulation of surface IL‐2Rβ, and early assembly of the high‐affinity IL‐2R, accelerating monocyte activation and function. High constitutive intracellular IL‐2Rγ expression (> 80%) in all types of leucocyte investigated, decreased over the 72 h following stimulation with a concurrent increase in surface expression. IL‐2Rγ was expressed by increased proportions of T cells, monocytes and NK cells, 4 h following stimulation. The intracellular storage of IL‐2Rγ may accelerate translocation to the cell surface after stimulation. The early translocation of IL‐2Rγ may reflect its usage as a signal transduction molecule by other cytokine receptors — IL‐4, IL‐7, IL‐9 and IL‐15. This study delineated the potential expression of the high‐affinity IL‐2Rα/β/γ on various stimulated leucocytes. The differential kinetics of assembly of the high‐affinity IL‐2Rα/β/γ on different leucocyte subsets suggests that IL‐2 may regulate the inflammatory cellular responses in a sequential manner, paralleling the timed expression of IL‐2Rα/β/γ on the monocytes, NK cells and T cells.