Anti-CD25 mAbs [7G7/B6](MABL-832)

MABL-832

IP, ELISA, FC, IF

Engineer antibody

Human

7G7/B6

Recombinant Antibody

This antibody is specific for human interleukin 2 (IL2) receptor alpha (IL2RA), which is expressed by activated T cells. IL2R alpha chains can exist as low-affinity monomers, or can non-covalently associate with IL2R beta chains to form high-affinity dimers.

IL2-RA; Interleukin-2 receptor subunit alpha; IL-2-RA; IL-2R subunit alpha; TAC antigen; p55; Receptor for interleukin-2

P01589

This antibody was raised by injecting mice intraperitoneally and subcutaneously with Hong Kong influenza virus-stimulated PBMC, which express human IL-2 receptor alpha. Immune splenocytes were subsequently fused with SP2/0 cells to produce stable hybridomas.

This antibody recognises human IL2RA, as confirmed by immunofluorescence, FACS and immunoprecipitation analysis (Rubin et al, 1985). Sequential immunoprecipitations have shown that 7G7/B6 binds to the same 50-55 kD surface molecule as anti-Tac, a murine mAb specific for the human IL-2 receptor. However, 7G7/B6 does not compete with IL-2 and anti-Tac for binding to IL2R expressed by activated PBMCs, indicating that 7G7/B6 recognises a distinct epitope on IL2R. 7G7/B6, therefore, recognises a different epitope on IL-2Rα to the humanised anti-Tac monoclonal antibody daclizumab (Zhang et al, 2006). Equally, although 7G7/B6 binds to a different epitope on IL2 Rα to IL-2, and is, therefore, unable to block IL-2/IL2 Rα interaction, 7G7/B6 is still able to delay tumour progression and prolong survival in mouse models of adult T-cell leukaemia (ATL) (Phillips et al, 2000), likely by FcR- mediated death by FcRIII-expressing cells. Administration of 7B7/B6 radiolabelled with astatine-211 (211At- 7G7/B6) to karpas299 leukaemia–bearing mice significantly increased survival, highlighting the potential therapeutic role for 211At-7G7/B6 in the treatment of patients with CD25-expressing leukaemias (Zhang et al, 2006). Indeed, 211At-7G7/B6 in combination with daclizumab induces significant long-term survival in murine models of adult T-cell leukaemia (Zhang et al, 2006). Additionally, 7G7/B6 armed with Yttrium-90 (90Y) significantly extends the survival of SUDHL-1 lymphoma-bearing mice significantly (Zhang et al, 2009), and presents another option for combination therapy with daclizumab. 7G7/B6 has been used in flow cytometric measurements of energy transfer efficiencies between FITC- and Cy3-conjugated mAbs bound to IL-2Rα, β, and γ subunits on Kit 225 K6 T cells, revealing that IL-2R subunits are preassembled on resting cells (Damjanovich et al, 1997). This antibody has also been used in an ELISA to assess serum levels of IL- 2R (Uziel et al, 1994).

Rubin et al A Monoclonal Antibody 7G7/B6, Binds to an Epitope on the Human Interleukin-2 (IL-2) Receptor That is Distinct From That Recognized by IL-2 or Anti-Tac HYBRIDOMA Volume 4, No. 2, 1985, Mary Ann Liebert, Inc., Publishers PMID：2408992

Describes the original generation and characterisation of this antibody.

100 μg Purified antibody.

1 mg/ml.

Protein A affinity purified

PBS with 0.02% Proclin 300.

Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at - 20⁰C.