A Novel Tax-Responsive Reporter T-Cell Line to Analyze Infection of HTLV-1.

Human T-cell leukemia virus type 1 (HTLV-1) infects CD4 T-cells through close cell-cell contacts. The viral Tax-1 (Tax) protein regulates transcription by transactivating the HTLV-1 promoter in the 5' long terminal repeat of the integrated provirus. Here, we generated a clonal Tax-responsive T-cell line to track HTLV-1 infection at the single-cell level using flow cytometry, bypassing intracellular viral protein staining.