GITR/NFκB Reporter Lentivirus

Background

GITR (glucocorticoid-induced TNF receptor-related protein, TNFRSF18) is a co-stimulatory receptor of the TNF receptor superfamily expressed on T cells and other immune cells, with high levels on regulatory T cells. Engagement of GITR by its ligand or by agonist antibodies activates downstream NF-κB signaling, enhancing effector T cell activation, proliferation, and survival and modulating regulatory T cell suppression. Through these effects, GITR co-stimulation strengthens antitumor immunity, making it a target for agonist-based immunotherapies. NF-κB is an inducible transcription factor that integrates immune signals to drive activation gene programs, so NF-κB-driven reporters provide a quantitative readout of GITR co-stimulatory signaling.

Product Description & Applications

The GITR/NFκB Reporter Lentivirus is an immunotherapy reporter system for measuring GITR co-stimulation of T-cell activation. The construct constitutively expresses human GITR and a blasticidin selection marker from an EF1α promoter, together with a dual reporter, secreted Gaussia luciferase and GFP, driven by NF-κB response elements. When GITR is engaged by an agonist antibody or GITR ligand on target cells, NF-κB signaling is activated and drives the reporters.

Sequential transduction generates stable, sensitive T-lymphocyte reporter lines suitable for screening GITR agonists. Secreted Gaussia luciferase accumulates in conditioned media for kinetic sampling without lysis, while GFP supports microscopy and flow cytometry. The VSV-G-pseudotyped particles are purified by PEG precipitation and sucrose gradient centrifugation and transduce difficult-to-transfect cells, including primary and thawed cultures.

About This Product

This 2-vial immunotherapy reporter system consists of a Vial 1 Receptor Lentivirus encoding human GITR under a constitutive promoter with antibiotic selection, and a Vial 2 Reporter Lentivirus encoding tandem NFAT (or NF-κB) response elements driving a dual reporter (GFP, GFP-P2A-GLuc, GLuc, RFP, RFP-P2A-GLuc). Sequential transduction and selection generates a dual-stable effector cell line that responds quantitatively to receptor stimulation with a ratiometric fluorescent + bioluminescent readout.

Secreted Gaussia luciferase (where included) accumulates in conditioned media, enabling kinetic sampling without cell lysis. The combined fluorescent and luminescent outputs allow parallel microscopy-based visualization and plate-reader luminometry from the same cell population — providing assay redundancy and flexibility for potency testing formats compliant with regulatory expectations for cell-based functional assays.