A rapid neutralization test for antibodies to bovine leukemia virus, with the use of rhabdovirus pseudotypes

Two rhabdoviruses, vesicular stomatitis (type Indiana) and Chandipura viruses, formed pseudotype particles with envelope antigens provided by bovine leukemia virus (BLV). The pseudotypes are infectious for calf, human, mink, and rat cells, but the most sensitive indicator proved to be the Vero cells. Infectivity of the pseudotypes was increased by DEAE-dextran present during adsorption. Sera of spontaneously infected cattle contained high titers (some over 1/10,000) of antibodies neutralizing the pseudotypes, whereas sera of cattle from uninfected herds possessed no neutralizing activity in 1/10 dilution. The neutralization of these pseudotypes can serve as a rapid and sensitive test for the detection of antibodies in the cattle infected with BLV.