LacZ inducible, antigen/MHC-specific T cell hybrids

Area of Science:

• Immunology
• Molecular Biology
• Reporter Gene Assays

Background:

• The interleukin-2 (IL-2) gene's NFAT enhancer element regulates gene expression in activated T cells.
• This regulatory element can be coupled to reporter genes like Escherichia coli lacZ.
• Previous work demonstrated the potential of NFAT-lacZ constructs for measuring T cell activation.

Purpose of the Study:

• To develop T cell hybrids that inducibly express lacZ.
• To establish a novel assay for detecting T cell receptor (TCR)-mediated activation.
• To provide a method for identifying unknown T cell antigens.

Main Methods:

• Generation of BWZ.36 and BWZ.36 CD8 alpha fusion partners by transfecting alpha-beta-BW5147 cells with an NFAT-lacZ construct.
• Fusion of these partners with normal T cells from immunized mice.
• Detection of lacZ activity in response to antigen/MHC complexes.

Main Results:

• Successfully generated T cell hybrids exhibiting specific lacZ induction.
• Demonstrated that lacZ activity correlates with antigen/MHC class II and MHC class I complex recognition.
• Showcased the lacZ assay as a simpler, faster, and more cost-effective alternative to traditional IL-2 assays.
• Highlighted the assay's capability to detect single T cell activation.

Conclusions:

• The NFAT-lacZ inducible T cell hybrid system provides a robust method for studying T cell activation.
• This assay facilitates the detection of rare antigen-presenting cells.
• The developed method serves as a foundation for expression cloning strategies to identify novel T cell antigens.