Transmission of human T-cell leukaemia virus type I into adult mice

Human T-cell leukaemia virus type I (HTLV-I)-transformed rabbit T-cells, F647a, were intraperitoneally injected into eight 10-week-old C3H/He and C3H/HeJ mice (1 × 107 F647a cells/mouse), respectively. Antibody titres against HTLV-I increased to a peak at 1-3 months after injection in both C3H/He and C3H/HeJ mice. At 12 months after injection, antibody titres of two of the eight C3H/HeJ mice became undetectable, whereas those of all the C3H/He mice still ranged from 1:10 to 1:40. Sera from both seropositive C3H/He and C3H/HeJ mice reacted with HTLV-I core proteins, but not with the env protein. HTLV-I proviral sequences were detected in two of eight C3H/He mice and three of the eight C3H/HeJ mice. These results suggest that HTLV-I is able to infect an adult mouse.