Blocking the Tim-3 signalling pathway enhanced the cytotoxic capabilities of HIV specific CD8+ T cells from chronic progressors by increasing; a) their degranulation capacity, b) their ability to release perforin, c) their ability to target activated granzyme B to HIV antigen expressing CD4+ T cells and d) their ability to suppress HIV infection of CD4+ T cells. This evidence concerns the gene PRF1 and HIV infectious disease.