T-Cell Receptor Mutation Assay for Monitoring Human Genotoxic Exposure

Abstract

Mutant T-cells defective in T-cell receptor (TCR) α or β gene expression among CD4+ T-cells can be detected as CD3 − CD4 + cells by two-color fl ow cytometry using anti-CD3 and anti-CD4 monoclonal antibodies labeled with different fl uorescent dyes. This is because incomplete TCR αβ/CD3 complexes are not transported to the surface membrane. TCR mutations are spontaneously generated at a frequency of about 2 × 10 −4 in peripheral CD4 + T-cells, and the mutant frequencies are dose-dependently increased by exposure to genotoxic substances such as ionizing radiation and chemicals. The TCR mutation assay was developed in 1990, and this method has since been applied to monitoring human genotoxic exposure. It has been proved that the assay has advantage in detection of chronic exposure in large-scale studies. Here, I will briefl y review past studies reporting the applications, and describe methods for both preparation of the target cells and detection of the mutant cells.