Anti-CTLA4 (Ipilimumab biosimilar - IgG1fut isotype)

Non-fucosylated human monoclonal antibody (mAb) against human CTLA-4

Anti-hCTLA4-hIgG1fut features the non-fucosylated (fut), constant region of the human IgG1 isotype and the variable region of ipilimumab. Ipilimumab is a fully human IgG1 monoclonal antibody that targets CTLA-4 (also known as CD152), a negative regulator of T cell activation. By binding CTLA-4, ipilimumab inhibits negative signals that physiologically downregulate T cell activation and exerts its therapeutic activity by upregulating the antitumor activity of T lymphocytes [1,2].

In addition, Ipilimumab induces antibody-dependent cell-mediated cytotoxicity (ADCC) and TNF-α production [3]. Ipilimumab has been approved by the FDA for the treatment of unresectable or metastatic melanoma. Ipilimumab is undergoing clinical trials for other types of cancers, including lung cancer [4].

Anti-hCTLA4-hIgG1fut is a non-fucosylated antibody. The absence of the fucose residue from the N-glycans of IgG-Fc results in dramatic enhancement of antibody-dependent cellular cytotoxicity (ADCC) without any detectable change in complement-dependent cytotoxicity (CDC) or antigen-binding capability [5,6].

Anti-hCTLA4-hIgG1fut was generated by recombinant DNA technology. It has been produced in Chinese hamster ovary (CHO) cells deficient for fucosylation and purified by affinity chromatography with protein G.

More isotypes of this antibody are available and can be used for comparison of biological activities such as ADCC (see below or in the 'upon request' section).

References:

Grosso JF. & Jure-Kunkel MN., 2013. CTLA-4 blockade in tumor models: an overview of preclinical and translational research. Cancer Immun. 13:5.
Maio M. et al., 2013. Update on the role of ipilimumab in melanoma and first data on new combination therapies. Curr Opin Oncol. 25(2):166-72.
Laurent S.. et al., 2013. The engagement of CTLA-4 on primary melanoma cell lines induces antibody-dependent cellular cytotoxicity and TNF-α production. J Transl Med. 11:108.
Tomasini P., 2012. Ipilimumab: its potential in nonsmall cell lung cancer. Ther Adv Med Oncol. 4(2): 43–50.
Yamane-Ohnuki N. & Satoh M., 2009. Production of therapeutic antibodies with controlled fucosylation.corresponding MAbs. 1(3): 230–236.
Mizushima T., 2011. Structural basis for improved efficacy of therapeutic antibodies on defucosylation of their Fc glycans. Genes Cells. 16(11): 1071–1080.

Figures

Comparison of ADCC potency for native and engineered anti-human CTLA-4 antibody isotypes: Raji-hCTLA4 cells were incubated with gradient concentrations of Anti-hCTLA4 or Anti-β-galactosidase (β-gal) mAbs for 1 hour. Jurkat-Lucia™ NFAT-CD16 effector cells were then co-incubated with targets cells for 6 hours. NFAT activation, reflecting the induced ADCC response, was assessed by determining Lucia luciferase activity in the supernatant using QUANTI-Luc™. Percentages of the maximal response normalized to the IgG1 isotype are shown.

Specifications

Specificity: Targets cells expressing human CTLA-4

Clonality: Monoclonal antibody

Clone: Ipilimumab (Anti-hCTLA4-hIgG1, kappa)

Isotype: Human IgG1fut, kappa

Control: Human IgG1fut

Source: CHO cells

Purity: Purified by affinity chromatography with protein G

Formulation: 0.2 µm filtered solution in 68 mM sodium phosphate buffer (pH 7.4) with 91 mM glycine, 5% w/v saccharose, and stabilizing agents

Tested applications: Flow cytometry and ADCC 

Quality control:

• Binding of Anti-hCTLA4-hIgG1fut to hCTLA4 has been validated using flow cytometry.
• The complete sequence of this antibody has been verified.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

Anti-hCTLA4-hIgG1fut purified monoclonal antibody is provided azide-free and lyophilized. It is available in two quantities:

• hctla4-mab13: 100 µg
• hctla4-mab13-03: 3 x 100 µg

Product is shipped at room temperature.

 Upon receipt, store at -20 °C.