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Updated: Jul 17, 2025
A Fluorescence-based Lymphocyte Assay Suitable for High-throughput Screening of Small Molecules
Published on: March 10, 2017
Development and application of an in vitro assay to assess target-independent B-cell activation by targeted TLR7
Ying Chen1, Siqun Zhou1, Komal Pradhan1
1Merck & Co. Inc., Rahway, NJ, USA.
Abstract:
Targeted immune agonist (TIA) comprising a TLR7 agonist conjugated to tumor-targeting antibodies have been shown to induce potent anti-tumor responses in various preclinical models. However, the clinical proof-of-concept of a TIA has been hampered by systemic dose-limiting immune-related toxicities, including rapid induction of anti-drug antibodies in patients. We have developed ELISPOT-based assay to measure activation of antibody-secreting cells (ASCs), intended to simulate the interaction between TIA and peripheral B cells as a tool to pre-clinically de-risk tumor target-independent peripheral B-cell activation by TIA. This method has proven to be robust and has fast turn-around time to evaluate the induction of spontaneous B-cell activation by TIA in a tumor target- and FcγR-independent manner. This novel ASC assay platform may serve as a preclinical tool to de-risk TIAs that can potentially induce immune-related adverse effects in the clinic.
Insights
We developed a new assay to predict immune side effects from targeted immune agonists (TIAs). This method helps de-risk TIAs by evaluating B-cell activation before clinical trials, improving patient safety.
Area of Science:
- Immunology
- Oncology
- Pharmacology
Background:
- Targeted immune agonists (TIAs) show promise in preclinical cancer models.
- Clinical application of TIAs is limited by dose-limiting toxicities and anti-drug antibodies.
- Preclinical models need better tools to predict immune-related adverse effects.
Purpose of the Study:
- To develop and validate an assay for assessing TIA-induced peripheral B-cell activation.
- To pre-clinically de-risk TIAs by evaluating off-target B-cell activation.
- To provide a tool for predicting immune-related toxicities associated with TIAs.
Main Methods:
- Developed an ELISPOT-based assay to measure antibody-secreting cell (ASC) activation.
- Simulated the interaction between TIAs and peripheral B cells.
- Assessed TIA-induced B-cell activation in a tumor target- and FcγR-independent manner.
Main Results:
- The developed ELISPOT assay is robust and provides fast turn-around times.
- The assay effectively measures spontaneous B-cell activation induced by TIAs.
- Demonstrated the assay's utility in evaluating TIA-induced B-cell activation.
Conclusions:
- A novel ASC assay platform has been established for preclinical evaluation of TIAs.
- This assay can serve as a valuable tool to de-risk TIAs with potential immune-related adverse effects.
- The platform aids in predicting and mitigating clinical toxicities associated with TIAs.
