Abstract: In this paper, a mathematical model for HTLV-I infection of CD4+ T cells that incorporates the CD8+ cytotoxic T-cell(CTL) response is studied. We establish two threshold parameters R0 and R1, the basic reproduction numbers for viral persistence and for CTL response, respectively. We also show that the parameter R1 can be used to distinguish asymptomatic carriers from HAM/TSP patients and as an important control parameter for preventing the development of HAM/TSP.

Key words: CTL response, HTLV-I infection, global stability, Lyapunov function