Cell System for TCR-Antigen Identification and Characterization

Cellecta offers engineered reporter cell lines and cloning constructs, as well as controls, to run the entire TCR-Antigen identification and characterization workflow in your lab, without requiring specialized equipment. Our portfolio of cells and reagents enables any academic, biotech, and pharma lab that has access to a flow sorter to identify and analyze T-Cell Receptor (TCR)-antigen interactions.

Fig. 1 Genes encoding TCR chains can be introduced and expressed in Jurkat TCR-Reporter Cells, which enable TCR-Epitope-MHC interactions to activate expression of GFP. In parallel, appropriate Human Leukocyte Antigens (HLAs) can be expressed in K562 Antigen-Presenting cells (APC). Antigens may then be loaded onto or co-expressed by the MHC-APC Cells to activate the Jurkat Reporter Cells with the appropriate TCR.

• Description
• How It Works
• Applications
• Resources

• Cell Lines Engineered to Assess Antigen-Receptor Interactions

  Jurkat TCR Knockout and Jurkat NFAT-GFP Reporter Cell Lines: The genes encoding the TCR α and β chains have been knocked out in this clonal derivative of the Jurkat E6.1 line. In addition, Cellecta has also created a clonal reporter cell line by introducing a stable NFAT-responsive GFP reporter into the TCR knockout cells so that activation of expressed TCRs can be easily detected by fluorescence. The Jurkat reporter line also expresses CD8, which is important to stabilize TCR-MHC interaction.

  K562 HLA-A-02:01 Antigen-Presenting Cell (APC) Lines: K562 cells have been engineered with the genes encoding the HLA-A-02:01 complex so that cells can effectively present peptide antigens to activate T cells with the appropriate TCRs. These K562 APC Cells are available with Puro or BFP expression markers for co-culturing with TCR-expressing Jurkat Reporter Cells.

  Also available are peptide-specific Jurkat TCR Reporter Lines expressing CMV, EBV, or FLU, to serve as control cell lines with known peptide constructs.

• How is the Jurkat TCR-Antigen Reporter Cell System Different from Other Functional Assays?

  • GFP Reporter Precision: Activation of NFAT-driven GFP expression enables real-time quantification of TCR–epitope binding events, eliminating reliance on downstream transcriptional profiling or cytokine readouts.
  • No Endogenous TCR Background: The CRISPR-engineered Jurkat TCR knockout cells ensure no interference from native TCRs, offering high signal-to-noise performance. CD8 boosts TCR signaling response.
  • Flexible Antigen Presentation: Use either peptide-pulsed APCs, dextramers, or express peptide construct libraries in K562 cells, depending on your experimental needs.
  • Contrast Signal from Noise: Run pre-made Control Cell Lines with CMV, FLU, and EBV peptides in parallel to establish baselines for TCR response.

  

  Fig 2: Different methods to evaluate peptide antigen–TCR interactions

• Applications

  • Epitope Screening: Efficiently screen synthetic peptide libraries or mini-gene libraries expressed in K562 APCs.
  • Vaccine Studies: Identify and validate small molecules or antibodies that modulate TCR activation; promising hits can be re-engineered into functional chimeric antigen receptors (CARs).
  • T Cell Signaling & Mechanism Studies: Analyze TCR signaling pathways in response to tumor- or virus-specific antigens and dissect molecular mechanisms driving T-cell activation.

• Resources

  • TCR-Antigen Reporter System Manual
  • Poster: A Practical Guide to AIR Profiling and screening of antigen-specific clonotypes for studies in vaccine development, autoimmunity and cancer (PDF)
  • Poster: Identification of TCR-specific epitopes using peptide libraries in engineered antigen-presenting cells

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