ADCC/CDC/ADCP Assay

Monoclonal antibodies (mAbs) are successful as therapeutics due in part to their ability to induce the destructive capabilities of the immune system against specific target cells. mAbs activate antibody-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells and antibody-dependent cellular phagocytosis (ADCP) by macrophages, and these activities are considered to be important mechanisms of action for many of these mAbs in vivo. Several mAbs also activate the classical complement pathway and promote complement-dependent cytotoxicity (CDC), although the level of efficacy varies greatly, depending on the mAb, the target antigen, and the tumor type. All of these effector functions are mediated by the Fc region of antibody and over the past decade, engineering of this region to enhance the cytotoxic activity of therapeutic antibodies has been a subject of intense investigation.

Creative Bioarray provides ADCC/ADCP/CDC assay services to determine the activity of the antibody and/or complement against specified target cell lines.

Antibody-Dependent Cellular Cytotoxicity (ADCC)

ADCC is an innate immune response resulting in the lysis of target cells, mediated by antibodies specifically binding to cell surface antigens. When therapeutic antibodies with ADCC activity bind to cells expressing the target antigen, they induce non-specific cytotoxic cells, such as NK cells, to interact with the Fc region of the antibody via the FcγIIIa receptor. These cytotoxic immune cells are then activated to release cytokines such as IFN-γ or TNF-α and cytolytic granules that induce cell death.

Our ADCC assays can help you understand whether your biologics binds to the target antigen, activates immune cells through their Fc receptors, initiates cell death, or alternatively determines if Fc-silencing methods are effective. Our ADCC assay portfolio also includes surrogate ADCC assays using engineered cell lines that stably express the FcγRIIIa receptor to eliminate donor-specific variability and provide viable solution for validation of these complex assays.

Antibody-Dependent Cellular Phagocytosis (ADCP)

The least common Fc effector function is ADCP. In this system, antibodies bind to cell surface antigens and induce cell death by phagocytosis rather than cell lysis. The Fc region of the antigen-bound antibody binds mainly to FcγIIa receptors on effector cells such as macrophages, monocytes, dendritic cells or neutrophils, which in turn induces phagocytosis of the target cells and subsequent cell death.

Our ADCP assays use macrophages or monocytes as effector cells for phagocytosis of target cells to understand the effectiveness of antibody binding to specific antigens through their Fc receptors. Our strong expertise in macrophage differentiation in vitro, combined with our customized methods and readout options, ensure a phagocytosis assay design tailored to you.

Complement-Dependent Cytotoxicity (CDC)

The complement system is part of the innate immune system comprising a series of inactive plasma proteins. When a therapeutic antibody with CDC activity binds to a cell expressing the target antigen, it induces binding to the complement C1q protein, which in turn induces a cascade of specific hydrolytic events of other complement proteins. This cascade results in the activation of the membrane attack complex (MAC) on the surface of a target cell. These terminal complement proteins polymerize to form pores in the membrane, thereby killing the target cell.

Creative Bioarray provides a robust platform that allows developers to qualify and measure CDC activity for a range of targets. We have developed ready-made solutions and also offer fully customized development for new targets.

Moving Your Therapeutic Candidates Forward

• 384-well assay: robust, automated and reproducible high-throughput assay for large-scale screening
• Single agents or combinations: flexible assay design that can be customized to fit your project
• Multiple donors: highly enriched NK cells from multiple donors to address donor-to-donor variability
• Extensive collection of human tumor cell lines: targeting your cell surface antigens of interest
• Many years of combination screening experience: expert data analysis and interpretation

To get more information, a quote or to schedule a teleconference, please contact us.

Related Services:

• Immune Checkpoint Assay
• Exploratory PK & Toxicity Studies
• Safety Pharmacology
• In Vivo Pharmacology