Flow cytometry evaluation of the T-cell receptor Vβ repertoire among human T-cell lymphotropic virus type-1 (HTLV-1) infected individuals:: Effect of interferon alpha therapy in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Human T-cell lymphotropic virus type-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is chronic inflammatory disease of the spinal cord characterized by perivascular lymphocytic cuffing and parenchymal lymphocytic infiltration. In this study using flow cytometry, we have investigated the T-cell receptor (TCR) V beta repertoire of peripheral blood T lymphocytes in 8 HAM/ TSP patients, 10 HTLV-1 infected healthy carriers, and 11 uninfected healthy controls to determine if there is a biased usage of TCR V beta. We found that TCR V beta 7.2 was under-utilized and V beta 12 was over-utilized in CD4(+) T cells of HTLV-1 infected individuals compared with healthy uninfected controls, whereas there were no such differences in CD8(+) T cells. Comparison of V beta repertoire changes before and after interferon-alpha (IFN-alpha) treatment for HAM/TSP revealed that one out of five patients showed dramatic decrease of specific V in CD8(+) T cells. Our results suggest that dominant V beta subpopulations in CD4(+) T cells evolved associated with chronic HTLV-1 infection, and IFN-alpha treatment for HAM/TSP does not induce a specific pattern of TCR V changes. (c) 2006 Elsevier B.V. All rights reserved.