The Murine IL-13 Receptor α2: Molecular Cloning, Characterization, and Comparison with Murine IL-13 Receptor α1
| Autor: | Debra D. Donaldson, Matthew J. Whitters, Lori J. Fitz, Tamlyn Yee Neben, Heather Finnerty, Sheryl L. Henderson, Richard M. O’Hara, David R. Beier, Katherine J. Turner, Clive R. Wood, Mary Collins |
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| Rok vydání: | 1998 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 161:2317-2324 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.161.5.2317 |
| Popis: | Two components of a receptor complex for IL-13, the IL-4R and a low affinity IL-13-binding chain, IL-13Rα1, have been cloned in mice and humans. An additional high affinity binding chain for IL-13, IL-13Rα2, has been described in humans. We isolated a cDNA from the thymus that encodes the murine orthologue of the human IL-13Rα2. The predicted protein sequence of murine IL-13Rα2 (mIL-13Rα2) has 59% overall identity to human IL-13Rα2 and is closely related to the murine low affinity IL-13-binding subunit, IL-13Rα1. The genes for both mIL-13-binding chains map to the X chromosome. A specific interaction between mIL-13Rα2.Fc protein and IL-13 was demonstrated by surface plasmon resonance using a BIACORE instrument. Ba/F3 cells that were transfected with mIL-13Rα2 expressed 5000 molecules per cell and bound IL-13 with a single Kd of 0.5 to 1.2 nM. However, these cells did not proliferate in response to IL-13, and the IL-4 dose response was unaffected by high concentrations of IL-13. In contrast, the expression of mIL-13Rα1 by Ba/F3 cells resulted in a sensitive proliferative response to IL-13. Consistent with its lower affinity for IL-13, IL-13Rα1.Fc was 100-fold less effective than IL-13Rα2.Fc in neutralizing IL-13 in vitro. These results show that mIL-13Rα2 and mIL-13Rα1 are not functionally equivalent and predict distinct roles for each polypeptide in IL-13R complex formation and in the modulation of IL-13 signal transduction. |
| Databáze: | OpenAIRE |
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