Transformation of guinea pig leukocytes by coinfection with human T-cell lymphotropic virus types I and II

OBJECTIVE: The susceptibility of guinea pigs to human T-cell lymphotropic virus (HTLV) infection and of their cardiac blood mononuclear cells (CBMCs) to HTLV-induced transformation were investigated. STUDY DESIGN/METHODS: Guinea pig CBMCs were cocultured with HTLV-infected cell lines. Guinea pigs were then inoculated with transformed guinea pig CBMCs. RESULTS: The coculture experiment gave rise to a guinea pig cell line, GP-1, that was coinfected with both HTLV-I and HTLV-II as shown by immunofluorescence staining, electron microscopy, polymerase chain reaction (PCR) using primers specific for the pol region of each virus, and Southern blot hybridization. The GP-1 cell line expressed T-cell markers and monocyte/macrophage markers. Three guinea pigs given an intraperitoneal inoculation of GP-1 cells seroconverted for HTLV-I and became positive for HTLV-I, HTLV-II, or both, as confirmed by PCR. CONCLUSIONS: Guinea pigs and their CBMCs can be infected with HTLV-I and HTLV-II. This animal system may be useful as an experimental model of HTLV-I and HTLV-II infection.