博尔纳病毒感染与精神分裂症的相关研究

目的 探讨博尔纳病毒(Borna disease virus,BDV)感染与精神分裂症的相关性,分析感染BDV的精神分裂症患者临床特征.方法 采用荧光定量巢式逆转录聚合酶链式反应方法检测86例精神分裂症患者(患者组)和84名健康体检者(对照组)外周血单个核细胞中BDVp24和BDVp40基因片段,以β-肌动蛋白作为内参照,将BDVp24和BDVp40基因片段均为阳性的标本基因进行测序分析,外周血进行抗BDV抗体滴度测定,对患者的精神症状采用PANSS进行量化评分,并总结阳性患者的临床特征.结果 86例精神分裂症患者中外周血标本BDV p24基因片段阳性检出率11.6％ (10/86),BDVp40基因片段检出率13.4％ (12/86),拷贝数均＞102 kb/μl.对照组检测BDVp24、BDVp40基因片段均为阴性,两组阳性率比较差异有统计学意义(x2=9.26,P＜0.05).对BDV p24和BDVp40基因片段均为阳性的标本测序后,与马源的BDV病毒株亲缘关系最近.阳性标本的精神分裂症患者精神症状主要以幻觉、妄想等阳性症状为主,PANSS量表评分均＞40分.结论 精神分裂症发病与BDV感染有一定的相关性,是否是唯一的相关性还有待进一步研究,BDV感染的精神分裂症患者主要以阳性精神症状为主.     

精神病病人Borna病病毒p23基因片段的检测

为探讨Ｂｏｒｎａ病病毒与人类精神疾病的关系，采用套式逆转录酶／聚合酶链反应技术检测７２例精神病病人和４０名健康献血者周围血单核细胞的Ｂｏｒｎａ病病毒ｐ２３基因片段。结果显示，精神分裂症组的ｐ２３阳性检出率（９．４％）稍高于健康对照组（７．５％），但差异无显著性；双相情感障碍组的阳性检出率（２１．１％）明显高于健康对照组（Ｐ＜０．０５）。提示人类双相情感障碍可能与Ｂｏｒｎａ病病毒感染有关。     

精神分裂症患者BDV—p24基因的扩增及其产物的测序鉴定

目的：扩增精神分裂症患PBMCs标本中博尔纳病病毒（Borna disease Virus,BDV)p24基因，并对基因扩增产物进行测序鉴定，分析其与标准株之间的差异。方法：用巢式RT－PCR方法检测黑龙江省精神分裂症患及正常人PBMCs中BDV－p24基因片段，对2例BDV－p24基因阳性的巢式RT－PCR产物进行测序，并与标准株比较。结果：9例精神分裂症患中有2例BDV－p24基因阳性，7例正常人标本中未发现BDV－p24基因阳性。测序结果进一步证实扩增产物为BDV－p24基因，其序列与标准株高度同源。结论：用巢式RT－PCR方法可以特异性扩增出BDV－p24基因，扩增产物序列与标准株高度同源，提示黑龙江省的精神分裂症的发生可能与BDV感染有关。     

重庆地区精神疾病患者Borna病病毒感染的初步报道

目的　研究中国人中是否存在Borna病病毒 (BDV)感染 ,以及探讨BDV感染是否与人类精神疾病有关。方法　收集精神疾病患者 80例 (精神分裂症 5 0例 ,情感性精神障碍 30例 )和健康献血者标本 6 0名。每例采血 10ml,分离外周血单个核细胞 ,提取RNA ;用BDV P2 4基因特异性内外引物进行套式逆转录聚合酶链反应 ,扩增产物经琼脂糖凝胶电泳和特异性探针的Southern印迹杂交检测。结果　 5 0例精神分裂症患者中检出BDV P2 4基因片段 5例 ( 10 % ) ,6 0名健康对照者均未检出 ,两者间的差异有显著性 (P <0 0 5 ) ;30例情感性精神障碍患者中检出 1例 ( 3% ) ,与健康对照者的差异无显著性。结论　重庆地区精神疾病患者中存在BDV感染 ;精神分裂症与BDV感染可能有一定关系     

Tardive dyskinetic syndrome in rats infected with Borna disease virus

Tardive Dyskinesia (TD) is a hyperkinetic movement disorder caused by chronic treatment of psychiatric patients with dopamine (DA) receptor blocking drugs (Stacy & Jankovic 1991). Although TD is one of the most important and frequently encountered iatrogenic disorders in clinical medicine, its pathophysiology is poorly understood. We have observed a hyperkinetic movement disorder in rats experimentally infected with a neurotropic RNA virus, Borna disease virus, that may provide important insights into the pathophysiology of TD. Like TD patients, infected rats show prominent orofacial dyskinesias. In keeping with the dopamine (Goetz & Klawans 1982) and anatomic (Fibiger & Lloyd 1984) hypotheses of TD, the Borna disease rat model shows enhanced behavioural sensitivity to DA agonists and selective striatal cell damage. There is also evidence of DA deafferentation and heterogeneous reduction of D2 binding in the caudate-putamen, particularly from sites implicated in oral behaviour. These observations on a virus-induced movement disorder offer novel approaches to TD pathogenesis.     

博尔纳病病毒感染与神经胶质瘤发生的相关性

目的 探讨博尔纳病病毒(BDV)感染与神经胶质瘤发生的可能相关性.方法 用Western-blot方法,对114例神经胶质瘤患者和110例脑外伤患者血清中BDV-p24特异性抗体进行检测.结果 114例神经胶质瘤患者血清中BDV-p24抗体阳性16例,阳性检出率为14.03％;作为实验正常对照的脑外伤患者血清,阳性3例,阳性检出率为2.72％.两组比较差异有统计学意义(P＜0.01).结论 神经胶质瘤患者血清中存在BDV的感染;BDV感染可能与神经胶质瘤的发生相关.     

博尔纳病病毒感染与精神分裂症关系的初步研究

目的:探讨精神分裂症患者发病与博尔纳病病毒(BDV)感染的关系,分析被BDV感染的精神分裂症患者临床特征。方法:用荧光定量巢式逆转录聚合酶链反应(FQ-nRT-PCR)方法检测86例精神分裂症患者(病例组)和84例健康体检者(对照组)外周血单个核细胞(PBMCs)中BDVp24和BDVp40基因片段,用β-肌动蛋白(β-actin)作为内参照,并总结阳性患者的临床特征,病例组采用阳性与阴性症状量表(PANSS)评分。结果:病例组外周血标本BDV p24基因片段检出率11.6%(10/86),BDV p40基因片段检出率14.0%(12/86),拷贝数均102kb/μl。对照组BDV p24、BDV p40基因片段均为阴性(0%,0/84),两组阳性率差异有统计学意义(P均0.05)。BDV p24和BDV p40基因片段均为阳性的标本测序后,与BDV标准病毒株V和马源的BDV病毒株H1766序列比较同源性分别为96.35%和98.85%。在4个位点出现基因突变(nt1649 T→C、nt1656 G→A、nt1670 C→T和nt1676 C→T)。该目的基因片段与马源的BDV病毒株亲缘关系最近。BDV阳性患者精神症状主要以幻觉、妄想为主。结论:精神分裂症发病与BDV感染有一定的相关性,BDV阳性患者以阳性精神症状为主要临床特征。     

病毒性脑炎患者Borna病病毒P24基因片段的检测

目的探讨Borna病病毒(BDV)感染与人类病毒性脑炎的关系。方法采用荧光定量套式逆转录酶聚合酶链反应(FQ nRT PCR)检测了59例临床诊断的原因未明的病毒性脑炎及112名健康人外周血单个核细胞(PBMC)中BDVP24基因片段。结果59例原因未明的病毒性脑炎患者中有3例PBMC中检出BDVP24基因片段,而112名健康对照均未检出。病毒性脑炎患者BDV阳性率(5.08%)高于健康对照,差异有统计学意义(P<0.05),且BDVP24基因片段检测阳性病例的脑脊液中其他常见致脑炎病毒(单纯疱疹病毒、带状疱疹病毒、腮腺炎病毒、柯萨奇病毒和巨细胞病毒)检查均为阴性。结论中国的部分病毒性脑炎患者中存在BDV感染,BDV感染与病毒性脑炎的发病可能有关。     

病毒性脑炎患者脑脊液博尔纳病病毒p40基因片段的检测

目的探讨贵州遵义地区病毒性脑炎中博尔纳病病毒(Borna disease virus,BDV)的感染情况以及BDV与病毒性脑炎的关系。方法采用荧光定量逆转录聚合酶链反应(FQ RT-PCR)方法检测了54例病毒性脑炎患者和45例外科手术患者(除外神经系统疾病及其他常见病毒感染性疾病)脑脊液(CSF)中BDV p40基因片段,对阳性产物进行基因序列测定及分析。结果病毒性脑炎患者CSF中BDV p40基因片段阳性率为11.1%(6/54),明显高于对照组(0),Fisher精确概率检验,P0.05;其中2例外周血单核细胞(PBMC)及CSF BDV p40基因片段均为阳性。PCR扩增的目的基因片段阳性产物测序后,与NCBI网站GenBank提供的BDV标准病毒株V核苷酸序列比较同源性为100%,未发生突变。结论遵义及周边地区部分病毒性脑炎患者中存在BDV感染;感染人体的BDV p40中段基因片段存在高度的保守性,变异小,BDV p40中段基因片段可能是证实BDV感染的敏感标记物。     

Developmental brain injury associated with abnormal play behavior in neonatally Borna disease virus-infected Lewis rats: a model of autism

Play behavior, nonsocial exploratory activity, and nonplay social interaction were observed in male juvenile Lewis rats with brain developmental injury following neonatal infection with Borna disease virus (BDV). These behaviors were tested using the ‘intruder-resident' paradigm, with social isolation of residents for six days prior to testing. Four experimental pairings of infected (BDV) and uninfected (NL) rats were studied as follows: NL–NL; NL–BDV; BDV–NL; and BDV–BDV (the first member is the resident, the second member is the intruder). Observation of social activities was carried out for 10 min on two consecutive days. Nonsocial exploratory activity (e.g. ambulation and rearing) was similar in BDV and NL residents. Duration of nonplay social investigation (e.g. sniffing, approach, and follow) was higher in BDV residents as compared to NL residents when tested on the first test day. On the second day, all rats showed similar level of nonplay social interaction. When confronted with NL intruders, NL residents exhibited significantly more play behavior compared to the NL–BDV, BDV–NL and BDV–BDV pairs, when play behavior was measured by the number of ‘pins'. Moreover, irrespective of a type of intruder, NL residents demonstrated higher play soliciting behavior than BDV residents, indicating attenuated readiness to play in BDV-infected rats. The number of pins and play solicitations in BDV–NL pairs significantly increased over the two days of testing, while play activity in NL–BDV pairs declined on the second test day. This pattern suggests that the degree of social reinforcement on the first day of testing affected the level of play on the second day. These data demonstrate deficits in play behavior and other social interactions following BDV-associated developmental brain injury, thus supporting the value of the neonatally BDV-infected rat as an animal model of autism.     

Amantadine in depressive patients with Borna disease virus (BDV) infection: an open trial

Objective: Originally introduced into pharmacotherapy as an antiviral compound, amantadine was shown to also have multiple pharmacological effects on the central nervous system. In addition, only a few studies reported on certain antidepressive properties of amantadine. This effect was highlighted by the discovery of its antiviral effect on Borna disease virus (BDV), which is hypothesized to be an etiopathogenetic factor to subtypes of affective disorders. Therefore, the therapeutical use of amantadine in BDV-infected depressive patients was investigated.

Methods: In this open trial, amantadine was added to antidepressive and/or mood-stabilizing compounds treating BDV-infected depressed patients (n=25) with bipolar or major depressive disorders. Amantadine was given twice a day (100–300 mg/day) for a mean of 11 weeks. Antidepressive treatment response was measured on the Hamilton rating scale for depression (HAM-D) and/or with an operationalized diagnostic criteria system (OPCRIT; version 3.31). Virological response was measured by expression of BDV infection parameters in blood samples.

Results: The overall response rate of the amantadine augmentation in the BDV-infected patients with regard to depressive symptoms was 68% after a mean of 2.9 weeks of treatment. Bipolar I patients improved faster and did not show any following hypomania. In addition, the decrease of depression tended to correspond with the decrease in viral activity.

Conclusion: Amantadine appears to show a remarkable antidepressive efficacy in BDV-infected depressive patients. The antidepressive effect in this open trial appeared to be comparable to standard antidepressives, possibly being a result of its antiviral effect against BDV as a potentially relevant etiopathogenetic factor in these disorders.     

Restricted expression of Borna disease virus glycoprotein in brains of experimentally infected Lewis rats

Aim: Borna disease virus (BDV) induces a persistent infection in the central nervous system (CNS) accompanied by a non‐purulent meningoencephalitis. BDV‐infection of Lewis rats provides an important model to investigate basic principles of neurotropism, viral persistence and resulting dysfunctions. To date, the in vivo strategies of BDV to persist in the CNS are not fully understood. Viral glycoproteins are main targets of the antiviral defence implicating a controlled expression in case of persistent infections. Therefore, we analysed the expression profiles of the BDV‐glycoprotein (BDV‐GP) and corresponding BDV‐intron II RNA in experimentally infected rat brains, focusing on their spatio‐temporal occurrence, regional, cellular and intracellular locations. Methods: This was carried out by immunohistochemistry and in situ hybridization. The expression pattern of the most abundantly expressed BDV‐nucleoprotein (BDV‐N) served as a reference. Results: BDV‐N mRNA was detected preferentially in the cytoplasm of neurones, whereas BDV‐intron II mRNA was found predominantly in the nucleus of brain cells. The genomic RNA was restricted to the nucleus. Expression of BDV‐GP was significantly lower than BDV‐N expression and mainly limited to cerebral cortex, hippocampus, amygdala and thalamus. BDV‐GP was restricted to larger neurones; BDV‐N occurred also in astrocytes, oligodendrocytes and ependymal cells. Conclusions: The expression profiles of BDV‐GP, BDV‐N and their mRNAs are significantly different, indicating that BDV‐GP expression is regulated in vivo. This might be achieved by restricted nuclear export and/or maturation of BDV‐intron II mRNA or limited translation as a viral mechanism to escape from the immune response and enable persistence in the CNS.     

Borna disease virus-induced hippocampal dentate gyrus damage is associated with spatial learning and memory deficits

In neonatally inoculated rats, Borna disease virus (BDV) leads to a persistent infection of the brain in the absence of an inflammatory response and is associated with neuroanatomic, developmental, physiologic, and behavioral abnormalities. One of the most dramatic sites of BDV-associated damage in the neonatal rat brain is the dentate gyrus, a neuroanatomic region believed to play a major role in spatial learning and memory. The absence of a generalized inflammatory response to neonatal BDV infection permits direct effects of viral damage to the dentate gyrus to be examined. In this report, neonatally BDV-infected rats at various stages of dentate gyrus degeneration were evaluated in the Morris water maze, a swimming test that assesses the rats' capacity to navigate by visual cues. Our data demonstrate progressive spatial learning and memory deficits in BDV-infected rats that coincided with a gradual decline in the estimated hippocampal dentate gyrus neuron density.     

High-avidity human serum antibodies recognizing linear epitopes of Borna disease virus proteins.

BACKGROUND: The recent observation that Borna disease virus (BDV)-reactive antibodies from psychiatric patients exhibit only low avidity for BDV antigen called into question their diagnostic value and raised the possibility that antigenically related microorganisms or self antigens caused the production of these antibodies. We further characterized the specificity of these antibodies.METHODS: We established a peptide array-based screening test that allows the identification of antibodies directed against linear epitopes of the two major BDV proteins, the nucleoprotein (N) and the phosphoprotein (P).RESULTS: Initial tests employing sera of BDV-infected mice and rats or horses with Borna disease revealed a high specificity and sensitivity of this test. All sera recognized epitopes of N, P, or both. Sera of noninfected rats, mice, and horses showed no signals on either peptide array. Several human sera that recognized BDV antigen by indirect immunofluorescence contained antibodies that recognized various linear epitopes of one or even both BDV proteins. Remarkably, antibodies purified from such human serum by matrix-immobilized peptides showed high-avidity binding to BDV antigens when assayed by IFA or Western blotting.CONCLUSIONS: These data suggest that reactive antibodies found in psychiatric patients indeed indicate infection with BDV or a BDV-like agent. However, the poor affinity maturation of BDV-specific human antibodies remains unexplained.     

Clinical investigation of the relationship between Borna disease virus (BDV) infection and schizophrenia in 67 patients in Japan

The relationship between Borna disease virus (BDV) infection and schizophrenia in the clinical time course was investigated. By nested reverse-transcribed polymerase chain reaction (RT-PCR) and Western blotting, BDV-specific RNA and anti-BDV antibodies were examined in the EDTA-treated blood from 67 schizophrenic patients (according to DSM-III-R) in Japan. A significantly higher proportion (45%) of anti-BDV antibody and/ or BDV RNA carriers were found among these 67 schizophrenic patients than in 26 controls (0%). There were no apparent associations of BDV infection with age, age at onset, period of hospitalization, accompanying somatic diseases, a past history of tuberculosis, a history of transfusion, a family history, or doses of psychotropic drugs. It is possible that, at least, BDV infection in schizophrenic patients may not be a nosocomial (hospital-acquired) infection, although the route of BDV infection in humans remains unidentified. More studies on the relationship between BDV infection and clinical psychosomatic features should be performed in order to elucidate the pathogenesis of schizophrenia.     

Anti‐Borna disease virus antibody responses in psychiatric patients: Long‐term follow up

Aim: Data suggesting a pathogenetic role for Borna disease virus (BDV) in neuropsychiatric diseases are still inconclusive and it is unknown whether humans become persistently infected or clear the virus infection. The aim of the present study was therefore to investigate long‐term BDV‐specific antibody responses in psychiatric patients in order to gain new insights into human BDV infection and its pathogenicity. Methods: BDV‐specific antibody titers and associations with clinical conditions were studied retrospectively in 94 seropositive patients with schizophrenia (n = 46), affective disorders (n = 19) and other psychiatric disorders (n = 29) who had been repeatedly tested for the presence of BDV‐specific antibodies on indirect immunofluorescence assay between 1985 and 2006. Long‐term titer dynamics were studied in 46 patients followed up for a period of >36 months. Results: A total of 25 of these 46 patients (54.3%) had persistent seropositivity, whereas seroreversion from positive to negative was observed in 21 (45.7%). Patients in the early course of schizophrenia had lower antibody titers compared to patients in the advanced course (P = 0.017), while a higher proportion of patients in the early course had titer increases (P < 0.05). There were no significant differences in antibody titers between patient subgroups with clinically stable and acute psychiatric disorders. Conclusion: Persistent seropositivity in a subgroup of psychiatric patients in the long‐term analysis suggests chronic BDV infection in humans.