title: Four epitopes on the rat 55-kDa subunit of the interleukin 2 receptor as defined by newly developed mouse anti-rat interleukin 2 receptor monoclonal antibodies.
abstract: Four new mouse monoclonal antibodies (mAb), ART-38, ART-35, ART-75 and ART-94, directed against the rat interleukin 2 receptor (IL 2R) have been developed. As shown by immunoprecipitation studies they all recognize specifically the 55-kDa subunit of the rat IL 2R. These mAb were compared to three previously characterized mouse mAb directed against the 55-kDa molecule of the rat IL 2R, namely the ART-18, ART-65 and OX-39 mAb. Out of all seven mAb, only ART-18 and OX-39 were found to inhibit the IL 2 binding to activated T cells, while IL 2R inhibited the binding of ART-18 alone. ART-18 was the only mAb found to inhibit the IL 2-dependent proliferation of cells carrying the IL 2R. Scatchard plot analyses showed gross differences in the numbers of mAb-binding sites ranging between 30,000 (ART-65) and 165,000 (ART-75) as well as in their affinities which ranged between 2.5 X 10(-9) M (ART-38) and 8.3 X 10(-10) M (OX-39). Cross inhibition studies revealed that the mAb recognize four different epitopes on the 55-kDa rat IL 2R subunit.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001667:Binding, Competitive; D000939:Epitopes / Q000276:immunology*; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology*; D015375:Receptors, Interleukin-2
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2