新生児肺炎ウイルス (HVJ, 仙台型) の研究 (第11報)

Abstract

Characteristic lesions on the endodermal layer of the chorioallantois removed from chicken embryos inoculated with Sendai virus has been already reported. These changes were rather proliferative than degenerative, such as bridge formation between cells of endodermal lining. Later, similar pathological features were also found on the bronchial cell of infected mice.Futher histopathological studies of the bronchial cell revealed inclusion bodies related to that described by Harford et al. with influenza virus. As Sendai virus is in particular position among the family of influenza virus, these cytoplasmic changes have been pursued both histopathologically and by electron microscopy with correlation to the viral growth in mouse lung, in order to get further information on the characteristics of this virus.In sections stained with hematoxylin and eosin, these bodies usually appeared 3 days after infection. At this early stage, they were basophilic and shaped as round or ovoid, within a day, the inclusions were surrounded by envelopes of acidophilic material. Though the small basophilic segments were still detectable after enlargement of the latter acidophilic matrix, final features of eosibophilic inclusions had no inner structure and seemed to be just homogeneous. These mature bodies were almost as large as nucleus.When these sections were stained by pyronine and methylgreen, basophilic part was stained by methylgreen and eosinophilic part by pyronin. However, mature bodies were Feulgen negative.These characteristic bodies were not detectable by instillation of normal allantoic fluid. Moreover, serotherapy of infected mice by injection of anti-HVJ serum prevented the appearance of the body. On the other hand, treatment of mice with xerosin had no effect on the appearance of these bodies. In this case though the lung lesions have been fairly retarded, virus growth was not affected at all. Thus the detection of inclusion bodies were correlated to the viral growth, but not to the inflammatory changes.Identification of inclusion bodies which have been demonstrated in ciliated cells of infected bronchial epithelium by electron microscopy with that found by optical microscopy was not studied in detail.In summary, the characteristics of cytoplasmic inclusions which have been detected in the bronchial epithelium of mice infected with Sendai virus, are quite similar to that reported by Harford et al. with influenza virus, but the criticism of Morgan et al. on the latter work, must be also considered in this study.