数種ウイルスの各種動物胎児組織培養における増殖と細胞変性作用について

Abstract

In order to elucidate host-virus-relationship, especially cytopathogenicity of viruses in tissue culture by using embryonic skinmuscle tissue, comparative studies on the cytopathogenic effects of western equine encephalomyelitis (WEE), eastern equine encephalomyelitis (EEE), Venezuelan (equine encephalomyelitis (VEE), Columbia SK (Col. SKO, Mengo encephalitis (Mengo) and both pantropic and neurotropic Rift Valley fever (PRY and NRV respectively) viruses were undertaken by means of morphological check on Giemsa's stained preparates under microscope and titration of virus in culture fluid in mice daily after their inoculation into the 6-7 day tissue culture of human-, pig-, ox-, mouse- and chickembryos. On the other hand the effect of each immune rabbit serum was investigated upon the cytopathogenicity of the homologous virus. The results obtained were briefly summarized as follows:1) The marked cytopathogenic effect of WEE, EEE and VEE viruses were observed on fibroblasts of human-, pig-, ox-, mouse- and chickembryos, and Col. SK, Mengo viruses and both PRV and NRV viruses gave the same findings as the viruses mentioned above except on chick embryo tissue culture.The cytopathogenic effect was found to be caused by the virus growth in tissue culture because of exsistence of parallelism between the titer of virus and the grade of cytopathogenicity which had been inhibited by the homologous immune rabbit serum.2) The viruses mentioned above might be classified on the morphological changes of the fibroblast at the early stage of tissue culture, into 3 groups, that is, equine encephalomyelitis group, Col. SK-Mengo group and RV groups. In equine encephalomyelitis group, the round, deep stained and pyknotic nucleus was found more often in the normaly stained protoplasma infected with VEE than with both WEE and EEE, and in the Col. SK-Mengo group, the elongated and deep staine pyknotic nucleus was recognized in infected cells while the characteristic karyorrhexis was found in cells infected with RV group.3) In spite of the growth of virus no cytopathogenic effect was confirmed in tissue culture infected with yellow fever 17D and Russian spring summer encephalitis viruses under our tissue culture conditions.4) The immune rabbit serum was added to the infected tissue culture within 1 to 8 hours after inoculation with heavy dosis. No cytopathogenic effect was observed but it did occur after replacement of culture media without antiserum 4 days thereafter. That means, the high potent immune serum could not completely inhibit the cytopathogenicity of the virus 8 hours after inoculation with the virus into tissue culture. Furthermore, it was confirmed that cytopathogenic effect could no more be inhibited by adding the immune serum into the infected tissue culture 8 hours or later after inoculation of the virus.