In vitro Pharmacology

  • Antibody-Mediated Immune Cell Functional Assay

In tumor microenvironment with human native immune system, once the tumor-specific targets are recognized by a particular antibody drug, the Fc part of the antibody would bind to the FcγR of native immune cells (such as NK cells and macrophages) and activate them, thereby eliciting effector functions to kill or phagocytose the target cancer cells. The Fc part of the antibody drug may also bind to the complement protein C1q in human serum, activating the complement system and eventually forming membrane attack complex which may act on the membrane of the target cancer cells and lyse them (See the graph below). We may utilize the MoA (Mechanism of Action) of these native immune cells to assess the functionalities of the antibody drugs in vitro.

Figure: Antibody-mediated immune cell functional assays, including Antibody-Dependent Cellular Cytotoxicity (ADCC), Complement-Dependent Cytotoxicity (CDC), and Antibody-Dependent Cellular Phagocytosis (ADCP)

ADCC, CDC and ADCP assays are relatively complex experiments, and many factors play roles to determine the success of the assay, including:

  1. Target molecule expression level on the target cell surface;
  2. Binding affinity of the antibody drug with the target molecule;
  3. The antibody drug IgG subclass;
  4. Potential effector function blockade mechanism on the target cell;
  5. Binding epitope on the target molecule for the antibody drug.

We will thoroughly evaluate your project and make our way to counter potential project risks to the largest extent. Our delivery standard, deliverables and project turnaround time are as follows:

Assay Type Delivery Standard Deliverable Turnaround Time
ADCC The EC50 value of the positive control falls within 5-fold range of the historic average value Raw data, Processed data, and final report 2 weeks
CDC 2 weeks
ADCP 4 weeks

Please download our quotation form, fill it carefully and send it to us at bioassay@genscript.com for a free project evaluation.

ADCC Assay

There are three formats of ADCC assays at in vitro bioassay platform:

Target Cell Effector Cell Advantage Disadvantage Applicable stage
1 Tumor cell line Human PBMC / Primary NK cell Closely related to the true body immune microenvironment More costly, relatively lower reproducibility between batches of primary cells, relatively low target cell expression on tumor cell line Antibody drug functional confirmation post-screening
2 Target overexpression engineered cell line Human PBMC / Primary NK cell Enhanced ADCC effect, relatively higher reproducibility Costly to construct overexpression cell line, more costly by using primary cells Early drug screening or functional confirmation post-screening
3 Target overexpression engineered cell line ADCC Reporter Gene Cell Line Relatively low cost, easy operation, high reproducibility, high success rate Cannot show true cytotoxic effect Early drug screening, batch-release during CMC

ADCC Service Key Features:

  1. Choose target cell line from more than 200 types of tumor cell lines and more than 100 different target expression engineered cell lines;
  2. Antibody drug positive controls* for popular targets are freely available;
  3. Use PBMCs from mixed donors, minimizing donor-to-donor variation;
  4. Fully validated ADCC reporter gene assay method is available;
  5. Stringent documentation system that meets the requirement of IND-filihg;
  6. Extensive experience from more than a hundred projects.

*CD20, Her2, CD38, EGFR, mTNFα, B7H3, Claudin 6, and Claudin 18.2 etc.

CDC Assay

CDC assay service key features:

  1. Choose target cell line from more than 200 types of tumor cell lines and more than 100 different target expression engineered cell lines;
  2. Antibody drug positive controls* for popular targets are freely available;
  3. Use serum from mixed donors, minimizing donor-to-donor variation;
  4. Suitable for mouse/rat antibody samples;
  5. Stringent documentation system that meets the requirement of IND-filing;
  6. Extensive experience from more than a hundred projects.

*CD20, CD38, mTNFα, B7H3, Claudin 6, and Claudin 18.2 etc.

ADCP Assay

There are three formats of ADCP assays at in vitro bioassay platform:

Target Cell Effector Cell Advantage Disadvantage Applicable stage
1 Tumor cell line M1/M2 type macrophages Closely related to the true body immune microenvironment More costly, relatively lower reproducibility between batches of primary cells, relatively low target cell expression on tumor cell line Antibody drug functional confirmation post-screening
2 Target overexpression engineered cell line M1/M2 type macrophages Biologically relevant, target cell line does not express “don’t eat me” signal, higher success rate Relatively costly to use primary effector cells, relatively lower reproducibility between batches of primary cells Early drug screening or functional confirmation post-screening
3 Target overexpression engineered cell line ADCP Reporter Gene Assay Cell Line Relatively low cost, easy operation, high reproducibility, high success rate Cannot show true phagocytosis effect Early drug screening, batch-release during CMC

ADCP Service Key Features:

  1. Choose target cell line from more than 200 types of tumor cell lines and more than 100 different target expression engineered cell lines;
  2. Antibody drug positive controls* for popular targets are freely available;
  3. Use PBMCs from mixed donors, minimizing donor-to-donor variation;
  4. Stringent QC criteria during macrophage differentiation and maturation;
  5. Fully validated ADCP reporter gene assay method is available;
  6. Stringent documentation system that meets the requirement of IND-filing;
  7. Extensive experience from more than a hundred projects.

*CD20, CD38, CD47/Sirpα, and Claudin 18.2 etc.

Brief information on detection method of ADCP assay:

Two distinct fluorescence dye are used to label target cell and effector cell respectively. Macrophages with target cell engulfed will show double positive fluorescence signal (See Q2 in the figure below).

  • No antibody drug added
  • With antibody drug added

“The quality of every bioactive component in ADCC, CDC and ADCP assays is critical to ensure the success of these experiments! QC is the key! ”

Dr Zhuo Fang

Senior Scientist for in vitro bioassay service platform in GenScript