Pseudo-high affinity interleukin 2 (IL-2) receptor lacks the third component that is essential for functional IL-2 binding and signaling.

• N Arima

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• M Kamio

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• K Imada

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• T Hori

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• T Hattori

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• M Tsudo

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• M Okuma

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

• T Uchiyama

  First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.

抄録

Functional studies of the interleukin 2 receptor (IL-2R) of two (ED515-D and Kit225) IL-2-dependent and three (ED515-I, 3T3-alpha beta 11, and Hut102) IL-2-independent cell lines were done. All of these cell lines appeared to express high as well as low affinity IL-2R. However, ED515-I and 3T3-alpha beta 11, which expressed the IL-2R beta chain, did not bind IL-2 at all when IL-2 binding to their IL-2R alpha chain was blocked with anti-Tac monoclonal antibody, whereas the intermediate affinity binding in ED515-D, Kit225, and Hut102 cells remained. We tentatively called the high affinity IL-2R of the former cells pseudo-high affinity IL-2R. The dissociation constant of pseudo-high affinity IL-2R was higher than that of ordinary high affinity IL-2R. Internalization of cell-bound 125I-IL-2 into ED515-I and 3T3-alpha beta 11 cells was less efficient than that into ED515-D cells. The addition of IL-2 neither promoted cell growth nor upregulated IL-2R alpha chain expression in ED515-I and 3T3-alpha beta 11 cells. Furthermore, tyrosine phosphorylation of the cellular proteins (p120, p98, p96, p54, and p38) was induced or enhanced in response to the addition of IL-2 in ED515-D and Kit225 cells, but not in the cell lines expressing pseudo-high affinity IL-2R. Finally, 125I-IL-2 crosslinking followed by SDS-PAGE analysis showed an 80-kD band corresponding to p65 + IL-2, in addition to bands corresponding to IL-2R alpha and beta chain + IL-2 in cells bearing ordinary high affinity IL-2R but not in cells with pseudo-high affinity IL-2R. Taken together, we consider that another protein whose molecular mass is approximately 65 kD is functionally important in IL-2 binding and subsequent signal transduction and may be the third component of IL-2R.

収録刊行物

• The Journal of experimental medicine

  The Journal of experimental medicine 176 (5), 1265-1272, 1992-11-01

  Rockefeller University Press

キーワード

• Immunology
• Immunology and Allergy

詳細情報

• CRID: 1361699995630526592
• NII論文ID: 30017432668
• DOI: 10.1084/jem.176.5.1265
• ISSN: 15409538
• ISSN: 00221007
• Web Site: https://rupress.org/jem/article-pdf/176/5/1265/1673532/1265.pdf
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