Safe blood products : Establishment of screening assay for Borna disease virus infection

精神疾病的病因尚不清楚。遗传和环境因素现在被认为与精神分裂症和抑郁症等精神疾病有关。本研究对与精神疾病有关的博尔纳病病毒（Borna disease virus，BDV）进行了研究。主要在德国进行的流行病学研究表明，BDV自然感染马、羊、牛、猫和鸵鸟。其中，部分马、羊感染BD V后诱发脑炎。我们已经报道了BDV在日本这些动物中的分布与在德国的分布相似。此外，我们还报道了BDV RNA可以检测到外周血单核细胞从这些感染的动物。此外，我们还发现，除精神分裂症外，BDV感染还与慢性疲劳综合征有关。但我们也检测到献血员血清中的抗BDV抗体和外周血单个核细胞中的BDV RNA，尽管这些患病率明显低于上述患者。因此，我们对BDV进行了研究，以提供安全的血液制品，结果表明：1）BDV在体外感染健康献血员外周血单个核细胞时，无明显复制; 2)在人血清中主要检测到BDV p24的抗体，而BDVp 4 O阳性的病例仅为罕见。同样，BDV RNA片段在人外周血单个核细胞中在p24区扩增，但很少在p40区扩增。为了解这些现象，我们对大鼠和长爪沙鼠颅内注射BDV进行了研究，结果表明新生动物中主要产生抗BDV p24的抗体，而成年动物中则同时产生抗BDV p24和p40的抗体。

The etiological agent(s) for psychiatric diseases is not known. Both of genetic and environmental factors are now believed to be involved in psychiatric diseases such as schizophrenia and depression. In this study, we have studied on Borna disease virus (BDV) which is suggested to be related with psychiatric diseases. Epidemiological studies worked mainly in Germany indicated that BDV naturally infects horses, sheep, cattle, cats and ostriches. Among them, some of BD V-infected horses and sheep induced encephalitis. We have reported that distribution of BDV in these animals in Japan is similar as that in Germany. Further, we have also reported that BDV RNA could be detected in peripheral blood mononuclear cells from these infected animals. Also, we found that in addition to schizophrenia, BDV infection is related with chronic fatigue syndrome. However, we also detected anti-BDV antibodies in sera and BDV RNA in peripheral blood mononuclear cells from blood donors, although these prevalences were significantly lower than those in above patients. Therefore, we have studied on BDV in order to supply safe blood products and obtained the results as follows :1) There are no apparent replication of BDV in the in vitro infection to peripheral blood mononuclear cells derived from healthy blood donors. 2) Antibodies to BDV p24 were predominantly detected in human sera, while the cases positive for BDVp4O were only rare. Similarly, BDV RNAfragments were amplified in human blood-derived peripheral blood mononuclear cells at p24 region, but only rarely at p40 region. To understand these phenomena, we examined intracranial injection of BDV to rats and mongolian gerbils.The results showed that antibodies were predominantly raised against BDV p24 in newborn animals, while against both BDV p24 and p40 in adults animals.