scFv(Control)-OX40-CD3zeta CAR-T Lentivirus

The scFv(Control)-OX40-CD3zeta CAR-T Lentivirus is a high-titer, replication-incompetent viral vector designed for the stable expression of a control Chimeric Antigen Receptor (CAR) in primary human T cells. The construct features a modular architecture comprising a non-targeting single-chain variable fragment (scFv) linked to a transmembrane domain, followed by the OX40 (CD134) costimulatory signaling domain and the CD3 zeta (CD3z) primary activation tail. Unlike antigen-specific CARs, the scFv component of this lentivirus lacks affinity for known human or murine proteins, functioning as a non-functional extracellular domain. This setup allows for the production of CAR-expressing T cells that retain the signaling machinery of a second-generation CAR without the capacity for antigen-induced activation. The vector is typically optimized for high transduction efficiency and provides a stable genetic baseline for downstream immunological assays.

This product is primarily employed as a negative control in adoptive cell therapy research to differentiate between antigen-driven responses and baseline CAR signaling. By utilizing scFv(Control)-OX40-CD3zeta CAR-T cells, researchers can effectively measure the degree of tonic signaling—activation that occurs independent of antigen binding—which is critical for understanding CAR-mediated exhaustion and survival. It serves as an indispensable reference in cytotoxicity assays, cytokine secretion profiling (ELISA/Luminex), and proliferation studies to ensure that observed therapeutic effects are specifically linked to the target antigen. Additionally, the lentivirus is used in in vivo xenograft models to evaluate the non-specific biodistribution and persistence of engineered T cells. In the development of novel CAR-T platforms, this control helps validate the contribution of the OX40 costimulatory pathway to T cell phenotype and metabolic fitness, ensuring that experimental results are accurate and reproducible across different T cell donors and manufacturing conditions.