(1269-B) Development of a high-throughput assay using exhausted T cells for screening immune checkpoint modulators
Monday, February 5, 2024
2:00 PM – 3:00 PM EST
Location: Exhibit Halls AB
Abstract: During a prolonged response to virus infection or tumorigenesis, effector T cells are persistently stimulated and become dysfunctional. Dysfunctional T cells overexpress inhibitory regulators, exhibit decreased effector cytokine production, and lose robust effector functions, leading to the failure of antigen/cancer elimination. In the present study, we established a protocol to generate dysfunctional T cells from human PBMCs and developed a fully automated high-throughput assay in 384-well format to assess immune checkpoint modulators. Specifically, PBMCs were maintained with IL-2 and leucoagglutinin PHA-L to induce dysfunctional T cells. Cell populations were subsequently examined and quantified using flow cytometry, and validated T cells were used for the further assay development. Following a 24-h stimulation with anti-CD3 and anti-CD28, cell supernatants were harvested for cytokine measurement (e.g., IL-2 and IFNγ) using AlphaLISA assays to evaluate the activation of T cell receptor (TCR) signaling. Cell lysates in the same assay plate were used for a viability assay to assess cytotoxicity. This workflow was implemented for immune negative regulators, PTPN1 and PTPN2, successfully demonstrating that a PTPN1/2 inhibitor, ABBV-CLS-484 promotes IFNγ production from dysfunctional T cells upon activation.