Monoclonal antibody defining a molecule possibly identical to the p75 subunit of interleukin 2 receptor.
A mouse hybridoma cell line, TU27, producing an mAb was established. TU27 mAb reacted with various human and Gibbon ape T cell lines bearing the IL-2R p75 (IL-2Rp75), but not with cell lines expressing only Tac antigen, IL-2Rp55, and numbers of its binding sites on cell surfaces were similar to those of high-affinity IL-2R. Radioimmunoprecipitation with TU27 mAb defined a molecule with a molecular mass of 75 kD on the surface of IL-2Rp75 bearing cells. TU27 mAb completely blocked IL-2 binding to IL-2Rp75 and to the high-affinity IL-2R but not to IL-2Rp55 composing the low-affinity IL-2R. The IL-2-dependent growth of a human T cell line, ILT-Mat, was significantly inhibited by TU27 mAb only at low concentrations of IL-2, and combination of TU27 mAb and H-31 mAb specific for IL-2Rp55 completely inhibited the cell growth even at high concentrations of IL-2. These data strongly suggest that TU27 mAb is specific for the human IL-2Rp75.
Takeshita
T
T
Department of Bacteriology, Tohoku University School of Medicine, Sendai, Japan.
Goto
Y
Y
Tada
K
K
Nagata
K
K
Asao
H
H
Sugamura
K
K
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002460:Cell Line; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008970:Molecular Weight; D011233:Precipitin Tests; D015375:Receptors, Interleukin-2 / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015375:Receptors, Interleukin-2