ADCP Assay Services
ADCP: A Pivotal Immune Mechanism in Therapeutic Antibody Development
Antibody-Dependent Cellular Phagocytosis (ADCP) is a critical immune effector mechanism employed by many therapeutic antibodies, particularly in oncology and infectious disease. It involves the recognition and engulfment of antibody-coated target cells by phagocytic immune cells like macrophages. Understanding and quantifying ADCP activity is paramount for predicting an antibody's in vivo efficacy and safety profile. Developing robust ADCP assays is essential to select optimal therapeutic antibody candidates, validate their mechanism of action, and strengthen preclinical data for regulatory submissions, ensuring a higher likelihood of clinical success. While gene therapy represents a distinct field, the principles of immune modulation, including effector functions like ADCP, are broadly relevant in understanding cellular responses that could impact any biological therapeutic.
Fig.1 Fc receptor-mediated interactions in viral infections.1
ADCP Assays at Creative Biolabs
Creative Biolabs' ADCP assays are meticulously designed to provide precise and reliable evaluation of your therapeutic antibody candidates, delivering critical data to advance your drug development pipeline. Our assays operate on the principle of antibody-mediated cellular uptake, where target cells opsonized (coated) with your therapeutic antibody are recognized and engulfed by phagocytic immune effector cells. This mechanism is crucial for the clearance of target cells in vivo. We measure the efficiency of this process quantitatively, providing a clear indication of your antibody's potential. Throughout the process, we offer comprehensive solutions tailored to your specific project needs, ensuring high-quality, actionable results grounded in scientific rigor.
This classic ADCP assay format leverages primary effector cells, specifically macrophages derived from human peripheral blood mononuclear cells (PBMCs). After careful isolation of fresh human PBMCs, monocytes are differentiated into macrophages in culture. This workflow is generally more sophisticated and typically requires over a week to complete. Phagocytosis events are meticulously analyzed using FACS screening, and a dose-dependent curve is generated to thoroughly assess the ADCP potency. It's important to note that effector cells from different donors cannot be pooled due to MHC restrictions, necessitating the use of samples from multiple donors to mitigate donor-specific variability. The Primary ADCP Assay serves as a powerful tool for early-phase confirmation of in vivo ADCP liability, as well as for the biocompatibility assessment of biosimilars and biobetters.
Recognizing the labor-intensive nature of primary cell-based assays, Creative Biolabs offers a surrogate Reporter ADCP Assay utilizing a robust reporter gene technique. This assay employs engineered Jurkat T cell lines stably expressing FcγRIIa (CD32a) as effector cells, and clients can provide custom target cells or select from our extensive library. The assay readout measures NFAT luminescent level, indicating effector cell activation. The Reporter ADCP Assay accurately reflects the ADCP mechanism of action with improved specificity, sensitivity, and accuracy, making it ideal for quality control, drug development, bio-comparability, lot release, and stability testing. While primary cell assays are valuable for early-phase MOA reflection, the reporter assay offers a fast, accurate, reproducible, and cost-saving approach for various stages of bioactivity assessment.
Our Workflow
01Step1. Cell Preparation & Seeding
- Target cells are labeled (e.g., with fluorescent dyes) and seeded into appropriate assay plates. Effector cells are prepared and counted to ensure optimal effector-to-target ratios.
02Step2. Antibody-Target Cell Opsonization
- Antibody candidates are incubated with the prepared target cells. This allows the antibodies to bind specifically to the target antigens on the cell surface, effectively "opsonizing" them for phagocytosis.
03Step3. Effector Cell Co-culture
- Washed effector cells are added to the antibody-opsonized target cells. The Fc domains of the bound antibodies engage with Fcγ receptors on the effector cells, initiating the phagocytic process.
04Step4. Phagocytosis Incubation
- The co-culture is incubated under optimized conditions (time, temperature) to allow for efficient phagocytosis. This step is critical for the uptake of target cells by the effector cells.
05Step5. Detection and Quantification
- Phagocytosis is typically quantified using high-throughput flow cytometry or high-content imaging, which measures the uptake of labeled target cells by effector cells. Advanced plate readers can also be employed for reporter assays.
06 Step6. Data Analysis & Interpretation
- Raw data are meticulously analyzed to determine the ADCP activity (e.g., phagocytic index, percentage of phagocytosis) of each antibody candidate. Concentration-response curves are generated, and EC50 values are calculated.
Service Highlights
- Predictive Power: High correlation with in vivo efficacy, enabling early selection of promising candidates.
- High Sensitivity: Detects even subtle differences in ADCP activity between antibody constructs.
- Robust & Reproducible: Delivers consistent and reliable data, crucial for preclinical validation.
- Customization: Flexible assay design to accommodate diverse antibody formats and target cell types.
- Comprehensive Data: Provides detailed quantitative analysis of phagocytic activity and potency.
FAQs
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Q1: What types of antibodies can be tested using Creative Biolabs' ADCP assays?
A1: Our ADCP assays are versatile and can accommodate a wide range of therapeutic antibody formats, including monoclonal antibodies, bispecific antibodies, and antibody-drug conjugates (ADCs). We can also customize the assay to suit novel antibody constructs.
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Q2: How sensitive are Creative Biolabs' ADCP assays, and what are the detection limits?
A2: Our assays are highly sensitive, capable of detecting subtle differences in ADCP activity. While specific detection limits depend on the antibody and cell types, our reporter assays offer enhanced sensitivity, providing robust data even for antibodies with moderate effector function. We can discuss your specific sensitivity requirements during consultation.
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Q3: Can Creative Biolabs customize the ADCP assay to use specific cell lines or patient-derived primary cells?
A3: Absolutely. We specialize in customizing ADCP assays. We can utilize your preferred target or effector cell lines, including patient-derived primary cells such as PBMCs or isolated macrophages, to ensure the assay accurately reflects your biological system of interest.
Related Sections
To further support your comprehensive therapeutic antibody development, Creative Biolabs offers a suite of complementary services that can be integrated with our ADCP Assays:
- Antibody-Dependent Cell-mediated Cytotoxicity (ADCC) Assay
- Complement-Dependent Cytotoxicity (CDC) Assay
- FcγRIIa Binding Assay
- FcγRI Binding Assay
- FcγRIIIa Binding Assay
Contact Us
Choosing Creative Biolabs for your ADCP assay needs means partnering with a leader in preclinical drug development. With over two decades of experience, we combine unparalleled scientific expertise with state-of-the-art platforms to deliver exceptional results. Our commitment to quality, customization, and rapid turnaround times sets us apart. Please don't hesitate to get in touch with us for more details.
Reference
- Jenks, Jennifer A et al. "The Roles of Host and Viral Antibody Fc Receptors in Herpes Simplex Virus (HSV) and Human Cytomegalovirus (HCMV) Infections and Immunity." Frontiers in immunology vol. 10 2110. 6 Sep. 2019, doi:10.3389/fimmu.2019.02110. Distributed under an Open Access License CC BY 4.0, without modification.
For Research Use Only.