Depletion Assay - PBMCs or Whole Blood
The expert immunologists at iQ Biosciences provide comprehensive Depletion Assays to evaluate the potential cytotoxic effects of therapeutic candidates on specific cell subsets. Using primary isolated PBMCs or fresh whole blood samples, our assays deliver precise, reproducible data to assess targeted depletion, or lack of depletion.
Our services
- Evaluate the impact of your therapeutics on specific cell subsets of interest within isolated PBMC or whole blood samples.
- Utilize co-staining with fluorescently labeled antibodies to identify cell populations of interest and assess both depletion efficacy and specificity.
- Customize experimental design, such as inclusion of relevant controls, to ensure the most biologically relevant data is obtained.
- Conduct all assays using high-quality reagents and strict controls.
- Deliver data in user-friendly formats such as PowerPoint, Excel, or GraphPad Prism for easy interpretation.
The iQ Experience
Tailored Experiments
Your research is important to us. Our scientists will work through each step of the process with you, including assay design, data analysis, and recommendations for future studies.
Streamlined Process
Simplify your workflow. Bypass the middle-man: at iQ Biosciences, you’ll get immediate access to our biospecimen inventory, saving you both valuable time and money.
Expertise
We’re experts – so you don’t have to be. Augmenting years of experience in immunology and working with immune assays, our scientists stay current with the latest publications and technology.
Exceptional Service
We’re here to help. We know the challenges you’re facing: whether it be through expedited service or our complimentary consulting services, our team is dedicated to helping you reach your goals.
Service overview
How can iQ Biosciences help achieve your goals the smarter way?
iQ Biosciences performs depletion assays to elucidate the cytotoxic effects of therapeutics on specific cell populations. These studies assess the combined effect of multiple cytotoxic mechanisms, which depend on the modality of the therapeutic under assessment. For example, monoclonal antibodies with Fc-mediated functions, such as Rituximab (targeting CD20), engage immune effector cells like natural killer (NK) cells or macrophages through Fc receptor binding. This interaction triggers cytolytic activity, leading to target cell elimination via antibody-dependent cellular cytotoxicity (ADCC) or antibody-dependent cellular phagocytosis (ADCP). Alternatively, T cell engagers (TCEs), such as Blinatumomab, simultaneously bind to target cell antigens and CD3 on T cells, redirecting T cells to release cytotoxic granules and induce apoptosis of the target cell.
Depletion assays also evaluate therapeutic specificity by incorporating fluorescent markers to distinguish target and non-target cell populations within PBMCs or whole blood. Our scientists provide guidance in selecting appropriate positive controls or benchmarks, as well as relevant negative controls to ensure assay accuracy. Leveraging high-throughput flow cytometry and testing across multiple donors, iQ Biosciences delivers robust insights to support preclinical decision-making.
In this assay, PBMCs or whole blood samples are incubated with a dose-response of the therapeutic candidate or relevant controls. Following an appropriate incubation period, the cells are co-stained with lineage-specific markers (e.g., CD4, CD8, CD20 or CD19, CD56, and CD14), along with a viability dye and counting beads. Cytotoxicity is assessed through viability dye incorporation, while depletion is quantified based on normalized cell counts. Key readouts include EC50 and maximum response values, providing a comprehensive evaluation of therapeutic potency and efficacy.
Figure 1: Depletion assay with human PBMCs. PBMCs were incubated with a dose response of test articles or controls, in triplicate, for 24 hours. After incubation, cells were stained with viability dye and a panel of fluorescent antibodies (anti-CD3, anti-CD19, anti-CD56, and anti-CD14). Counting beads were included during acquisition by high-throughput flow cytometry. Gates were applied to populations of interest, excluding viability dye-stained cells, and absolute counts per well calculated. Data normalized as a percent of the baseline untreated condition are shown. Each point represents the mean average of triplicate samples and error bars are SEM. Anti-CD52 (human IgG1, shown in blue) included as a positive control for T cell and NK cell depletion. Anti-CD20 (human IgG1, shown in green) included as a positive control for B cell depletion. The test article of interest, shown in red, is a therapeutic candidate without proposed impact on immune cell viability or depletion activity, confirmed here as a lack of depletion across major immune cell types.
Figure 2: Depletion assay with fresh human whole blood. Whole blood samples were incubated with a dose response of test articles or controls, in triplicate, for 24 hours. After incubation cells were stained with viability dye and a panel of fluorescent antibodies (anti-CD3, anti-CD19, anti-CD56, anti-CD8, anti-CD4, anti-CD25, anti-CD66b, and anti-CD14). Samples were fixed and permeabilized prior to staining with anti-FoxP3. Counting beads were included during acquisition by high-throughput flow cytometry. Gates were applied to populations of interest, excluding viability dye-stained cells, and absolute counts per well calculated. Data normalized as a percent of the baseline untreated condition are shown. Each point represents the mean average of triplicate samples and error bars are SEM. Anti-CD52 (human IgG1, shown in blue) included as a positive control for T cell and NK cell depletion. Anti-CD20 (human IgG1, shown in green) included as a positive control for B cell depletion. The test article of interest, shown in red, is a therapeutic candidate without proposed impact on immune cell viability or depletion activity, confirmed here as a lack of depletion across major immune cell types, including neutrophils, as well as regulatory T cells (Tregs).
Order Information
Pricing
At iQ Biosciences, we understand that each client is unique. Upon quote request, we will provide complimentary consulting services to determine how to tailor our services to best meet your goals. Based on this preliminary assessment, we will be able to provide a price quote.
Expected Timetable
Fit a timetable appropriate to your research goals. We work with you to determine your expected turn-around on a case-by-case basis and ensure that our services fit your needs. Some experiments may require an expedited service – please inquire for more information.
