Infectious transmission of human T‐cell leukemia virus to rabbits

A rabbit lymphoid cell line (Ra-1) was established by co-cultivation with a human T-cell line (MT-2) carrying human T-cell leukemia virus (HTLV). The Ra-1 cell line is chromosomally male and is persistently infected with HTLV. Ra-1 cells, with or without mitomycin C treatment, were inoculated intravenously (i.v.) into 3 female rabbits. All 3 animals responded with the production of antibodies to HTLV antigens. Lymphocytes from one of these seroconverters were cultured in the presence of T-cell growth factor (TCGF) and HTLV particles were detected in the TCGF-grown lymphocytes which were chromosomally female. Co-cultivation of lymphocytes from the 2 other seroconverters with lymphocytes from 2 anti-HTLV-negative healthy men gave rise to the establishment of an HTLV-producing T-cell line derived from each individual. Blood transfusion from one of the HTLV-infected rabbits into 2 female rabbits also resulted in the seroconversion of both recipients. An HTLV-carrying lymphoid cell line (Ra-2) was established from one of the transfusion-related seroconverters. The Ra-2 cell line was initially TCGF-dependent but later became TCGF-independent. There results indicate that HTLV can be transmitted to rabbits. These animals may provide a suitable model system for studying the mode of transmission and pathogenicity of HTLV.