Category: Immune monitoring
Gluten-challenge in subjects with celiac disease, results in a transient upregulation of gliadin-specific CD4+ T cells in the blood. Despite the increase, these cells are quite rare requiring a selective and sensitive assay for detection. We have developed a 12-color tetramer flow assay to enable detection and immunophenotyping of the gliadin α-I/α-II CD4+ T cells in the blood.
The assay was validated using healthy cryopreserved AccuCell™ PBMCs and CD4+ T cells spiked with T cells specific for gliadin α-I (QLQPFPQPELPY) or gliadin α-II (PQPELPYPQPE). The assay conditions were optimized for sensitivity, optimal signal:noise ratio, and detection of the gliadin α-I/α-II tetramers. The assay identifies gluten-specific (tetramer+) T cells and immunophenotypes the cells as either naïve or memory (CD4/CD3/CD45RA/CD62L/CCR7), activated (CD38), regulatory (CD39) and gut-homing (b7/a4). For validation, pre-specified criteria were used to assess inter-assay, intra-assay, inter-operator precision and post-staining stability. Technical validation was successfully met; and the assay performs within acceptable precision parameters.
Tetramer positive T cells in the blood are rare events; therefore, this assay was developed and validated to be sensitive and selective. This assay will enable characterization of the gliadin α-I/α-II CD4+ T cells in the blood for celiac patients, providing a more comprehensive evaluation of response to new therapies and may reduce invasive biopsy-based measurements.
Will McAuliffe– Scientist, Quantitative Translational Sciences, Takeda Pharmaceuticals
Lynn Kisselbach– Senior Scientist, Precision for Medicine
Angelina Bisconte– Director of Translational Biology & Biomarker Development, Precision for Medicine
William Kwok– Professor, Benaroya Research Institute
Deborah Phippard– Senior Vice President of Research, Precision for Medicine
Jose Estevam– Associate Director and Head of Ligand Binding Sciences, Takeda Pharmaceuticals
Glennda Smithson– Scientific Director Translational Medicine, Gastroenterology Drug Discovery Unit, Takeda Pharmaceuticals