Submitted October 17, 2007
Accepted December 17, 2007
High frequency of CD4+FoxP3+ cells in HTLV-1 infection: inverse correlation with HTLV-1-specific CTL response
Frederic Toulza*, Adrian Heaps, Yuetsu Tanaka, Graham P Taylor, and Charles R M Bangham
Department of Immunology, Imperial College, London, United Kingdom
Graduate School and Faculty of Medicine, University of Ryukyus, Okinawa, Japan
Department of Genito-Urinary Medicine, Imperial College, London, United Kingdom
* Corresponding author; email: f.toulza{at}imperial.ac.uk.
Evidence from population genetics, gene expression microarrays and assays of ex vivo T cell function indicates that the cytotoxic T lymphocyte (CTL) response to human T lymphotropic virus Type 1 (HTLV-1) controls the level of HTLV-1 expression and the proviral load. The rate at which CTLs kill autologous HTLV-1-infected lymphocytes differs significantly among infected people, but the reasons for such variation are unknown. Here, we demonstrate a strong negative correlation between the frequency of CD4+ FoxP3+ Tax- Tregs in the circulation and the rate of CTL-mediated lysis of autologous HTLV-1-infected cells ex vivo. We propose that the frequency of CD4+ FoxP3+ Tax- Tregs is one of the chief determinants of the efficiency of T cell mediated immune control of HTLV-1.
