The characteristics of a monoclonal antibody that binds specifically to rat T lymphoblasts and inhibits IL 2 receptor functions.
In order to obtain an anti-interleukin 2 (IL 2) receptor antibody, we immunized mice with phorbol myristate acetate-pulsed rat T lymphoblasts. The spleen cells of the mice were fused with myeloma cells. Several stable clones of hybridoma cells were obtained that produced monoclonal antibodies (mAb) reacting specifically with rat T lymphoblasts. Only one of these mAb, the mAb ART18, showed characteristics of a putative anti-IL 2 receptor antibody. This mAb was produced on a large scale, purified, and characterized. As tested by a binding assay, 125I-labeled mAb ART18 bound to rat T lymphoblasts (7.5 X 10(4) binding sites per cell), but not to thymocytes or spleen cells of rat origin, or to lymphoblasts, thymocytes, or spleen cells of murine origin. Only marginal binding to lipopolysaccharide-stimulated rat lymphoblasts was detected. The mAb ART18 inhibited in a species-specific and dose-dependent manner i) the capacity of rat T lymphoblasts to absorb IL 2 activity and ii) the capacity of rat T lymphoblasts to proliferate in response in IL 2. The function of T lymphoblasts of murine origin was not affected by the mAb ART18. The time course of the acquisition by mitogen-stimulated spleen cells of the capacity to absorb IL 2 activity was paralleled by that of their capacity to bind 125I-labeled mAb ART18. According to these data, the mAb ART18 seems to be directed against an antigenic determinant of the IL 2 receptor molecule.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002454:Cell Differentiation; D002455:Cell Division; D003208:Concanavalin A / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D007376:Interleukin-2 / Q000378:metabolism*; D051381:Rats; D011971:Receptors, Immunologic / Q000276:immunology* / Q000378:metabolism; D015375:Receptors, Interleukin-2; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A