CMV-CD81-GFP-FLAG Lentivirus

The CMV-CD81-GFP-FLAG lentivirus is a versatile, ready-to-use expression system that combines powerful transcriptional control with multimodal protein detection, enabling stable, long-term expression of a CD81 fusion protein in a variety of mammalian cell types. Driven by the cytomegalovirus (CMV) promoter, this expression cassette provides high-level constitutive expression in many commonly used cell lines and primary cells, making it suitable for applications requiring strong signals and sustained expression. The lentiviral vector efficiently transduces both dividing and non-dividing cells and supports genomic integration, thus maintaining transgene expression over prolonged culture and cell passages. By fusing CD81 with both GFP and a FLAG epitope, this construct offers multiple orthogonal detection modalities: GFP allows for direct real-time visualization in live cell imaging and rapid detection assays, while the FLAG tag supports sensitive and specific antibody detection for Western blotting, immunofluorescence, immunoprecipitation, and affinity enrichment.

This construct is particularly well-suited for research centered on CD81 biology and extracellular vesicles, as well as applications requiring simultaneous imaging and immunodetection. CD81 is a widely expressed tetraspanin protein and a typical marker and functional component of exosomes and other extracellular vesicles; expressing the CD81-GFP-FLAG fusion protein allows researchers to visualize membrane distribution and transport dynamics, track vesicle biogenesis and release in live cells, and enrich or detect CD81-associated complexes via the FLAG epitope. In cell biology and signaling studies, this system facilitates interactome analysis by combining fluorescence-based localization with biochemical pull-down experiments, helping to elucidate the role of CD81 in membrane microdomain organization, receptor clustering, and intercellular communication. In immunology, it can be used to assess how CD81 modulation affects immunological synapse formation, activation thresholds, or migration, and to perform rescue experiments in a CD81-deficient background to distinguish between direct and compensatory effects.