Investigating MAIT cell phenotype using MR1 and TCR Dextramer^® reagents

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Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B211
Abstract ID: 5364

Presenting Author:
Thomas H Blicher , Senior Scientist at Immudex

Abstract:

Objective

Here, we demonstrate a workflow, which enables the study of mucosal-associated invariant T (MAIT) cells using MR1 reagents. The workflow covers initial detection of MAIT cells with TCR sequencing as well as cloning, production, and validation of selected MAIT TCR molecules.

 

Methods

Human PBMC samples were stained with relevant antibodies and MR1/5-OP-RU dCODE Dextramer^® reagents. Following staining, sorting, and partitioning on a BD Rhapsody^TM Single-Cell Analysis System, the cells underwent sequencing for characterization of gene and surface marker expression as well as paired alpha-beta TCR sequences. Selected TCR sequences were produced as TCR molecules and subsequently used to detect MR1/5-OP-RU on the surface of antigen-presenting cells.

 

Results

The majority (70%) of the MAIT cells express typical TCRs containing TRAV1-2 and TRAJ33 gene segments. The remaining MR1/5-OP-RU-reactive MAIT cells express highly diverse, non-classical MAIT TCR sequences. The three most frequent TCR clonotypes were produced and their specificity validated using in vitro assays and staining of MR1/5-OP-RU-presenting cells.

 

Summary

Our workflow allows identification of MAIT cells and elucidation of their TCR sequences. The high sensitivity of MR1 dCODE Dextramer reagents enables detection of both weak interactions and rare cell types. Subsequent production of MAIT TCR molecules allows deeper characterization of individual MAIT cell specificity and its role in health and disease.