Transmission of HTLV‐I to rabbits via semen and breast milk from seropositive healthy persons

Abstract

Four rabbits inoculated intravenously with milk cells from 4 post‐partum women seropositive for human T‐cell leukemia virus type 1 (HTLV‐1) and one rabbit inoculated with semen cells from a seropositive healthy man seroconverted for HTLV‐1 after 3–5 weeks but no seroconversion occurred in 2 rabbits inoculated with milk cells from a seronegative mother or with heated (56°C, 30 min) milk cells from a seropositive mother. Attempts were made to isolate HTLV‐1 from peripheral blood lymphocytes harvested 5–15 weeks after cell inoculation and cultured in the presence of interleukin‐2. An HTLV‐1‐carrying lymphoid cell line of rabbit origin was established from a rabbit inoculated with milk cells. Another long‐term culture, derived from a rabbit inoculated with semen cells, also expressed HTLV‐1 antigens and harbored virus particles. Furthermore, transfusion of 20 ml of blood from all 5 seroconverted rabbits, but not from the 2 seronegative ones, caused seroconversion in normal recipient rabbits after 4–6 weeks.