The effects of a trichothecene, T-2 toxin, on growth of Japanese encephalitis virus in chick embryo cells and mice.

Abstract

The effects of T-2 toxin on the infection of Japanese encephalitis (JE) virus were examined in the vaccinated and the non-vaccinated mice. 1) In the non-vaccinated mice, when they received 2mg/kg of T-2 toxin intra peritoneally 6 times every other day before intracerebral injection of JE virus, all of them died within 5 days after the JE virus infection, while only three of ten mice of non-treat ment with T-2 toxin died more slowly by the JE virus infection during the period of ob-servation. 2) In the vaccinated mice, similar pretreatments with T-2 toxin before vaccination also caused early death of mice after the JE virus infection. The early death of JE virus infected mice suggests that T-2 toxin impairs some natural defense mechanism. 3) Neutralization antibody titers of the pooled sera from vaccinated and T-2 toxin treated mice were compared with titer of the pooled sera from non-treated with T-2 and vaccinated mice. There was no significant difference between them. 4) The growth of JE virus in chick embryo cells was completely inhibited when more than 10 ng/ml T-2 toxin was present in the culture medium. The synthesis of JE virus specific RNA was not affected with T-2 treatment in the early stage of the infection (from 3 hr to 6 hrs) but was inhibited with T-2 treatment in the late stage of the infection (12 hrs).