Development of T cell lines sensitive to antigen stimulation

Area of Science:

• Immunology
• Cell Biology
• Molecular Biology

Background:

• Immortalized T cells like hybridomas are valuable for studying peptide-MHC-TCR interactions.
• Their lower sensitivity compared to primary T cells can lead to false negatives, especially for low-affinity TCRs.

Purpose of the Study:

• To enhance the sensitivity of T cell hybridomas for antigen discovery.
• To overcome limitations in detecting low-affinity T cell receptor (TCR) interactions with peptide-MHC (pMHC) complexes.

Main Methods:

• Genetically engineered T cell hybridomas by introducing additional CD3 molecules.
• Modified T cell hybridomas to express CD4 with specific amino acid substitutions to increase MHC class II affinity.
• Transduced engineered cells with retroviral vectors encoding specific TCRs.

Main Results:

• Engineered T cell hybridomas demonstrated more robust responses to cognate antigens compared to non-manipulated cells.
• Enhanced responsiveness was observed without inducing non-antigen specific reactivity.
• The modifications successfully increased T cell hybridoma responsiveness across diverse TCR, peptide, and MHC class II combinations in humans and mice.

Conclusions:

• Genetic engineering of T cell hybridomas with CD3 and mutated CD4 significantly improves their sensitivity for antigen detection.
• This approach is effective across various MHC class II loci and species, making it a versatile tool for identifying T cell antigen specificity.