Characterization of the murine IL-5 receptor complex with the use of a panel of monoclonal antibodies. Relationship to the murine IL-3 receptor.
To obtain mAb against the murine IL-5R (mIL-5R), Wistar rats were immunized with B13 cells, a murine Ly-1+ (CD5+) pre-B cell line which is dependent on IL-3 or IL-5 for its growth. A first group of six mAb could immunoprecipitate, from detergent-lysed B13 cells, a 60-kDa polypeptide (p60) corresponding to the recently cloned mIL-5R alpha-chain. A second group of three mAb was able to immunoprecipitate a protein doublet of 130 to 140 kDa (p130 and p140) corresponding to the previously characterized mIL-3R and mIL-3R-like polypeptide, respectively. One mAb (25C9) specifically bound the p130 polypeptide only. Here we show that: 1) mAb directed against the mIL-5R p60 component completely block IL-5 binding; 2) mAb recognizing the p130-p140 doublet interfere with both IL-3 and IL-5 binding; 3) mAb recognizing p130-p140 block the high affinity binding of IL-5 and hence the high affinity mIL-5R consists of the association of the p60 and p130 and/or p140 component; 4) one particular mAb, 25C9, which binds only to the p130 polypeptide, interferes with only IL-3 binding, and has no effect on the binding of IL-5. These results on binding were corroborated by a biologic assay based on the cytokine-dependent proliferation of B13 cells. The results presented here support a model for the mIL-5R consisting of the alpha-chain (p60) associated with the p140 (IL-3R-like), whereas the p130 (IL-3R) is not involved in the IL-5R complex.
Roche Research Gent, Gent, Belgium.
J
J
Van der Heyden
R
R
Devos
G
G
Plaetinck
I
I
Fache
W
W
Fiers
J
J
Tavernier
D000818:Animals; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000502:physiology*; D002460:Cell Line; D066298:In Vitro Techniques; D015848:Interleukin-5 / Q000378:metabolism*; D051379:Mice; D011971:Receptors, Immunologic / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D018123:Receptors, Interleukin; D016185:Receptors, Interleukin-3 / Q000737:chemistry; D053649:Receptors, Interleukin-5
D000911:Antibodies, Monoclonal; D015848:Interleukin-5; D011971:Receptors, Immunologic; D018123:Receptors, Interleukin; D016185:Receptors, Interleukin-3; D053649:Receptors, Interleukin-5