Direct interferon-gamma-mediated protection caused by a recombinant coxsackievirus B3

Coxsackievirus B3 (CVB3) is one of the most important causes of viral myocarditis. Cytokines are involved in the control of CVB3 replication and pathogenesis. Local expression of specific cytokines by recombinant CVB3 confers prevention of virus-caused myocarditis. Expression of IFN-gamma by CVB3(IFN-gamma) protected BALB/c and C57BL/6 mice when the lethal infection with the highly pathogenic CVB3H3 variant was given directly after or prior to CVB3(IFN-gamma) inoculation by decreasing the viral load and spread as well as tissue destruction. This direct effect was not restricted to the homologous virus. In vitro, cocultivation of CVB3(IFN-gamma)-infected cells induced a reduction of CVB3H3 replication and virus-induced cytopathogenicity.     

Expression of cytokine mRNAs in murine hearts with acute myocarditis caused by coxsackievirus B3

In murine acute viral myocarditis, natural killer (NK) cells infiltrate the heart first, followed by activated T-cells, which play an important role in the pathogenesis of the myocardial damage. Because of their multipotential effects, cytokines are thought to play a role in the induction and development of these immune processes. To clarify in more detail the precise mechanism of the cytokine networks involved, the expression of various cytokine mRNAs has been investigated in myocardial cells infected with Coxsackievirus B3 (CVB3) in vivo and in vitro by a semiquantitative polymerase chain reaction (PCR) method. Interleukin (IL)-1α, IL-1β, IL-6, tumour necrosis factor (TNF)-α, and TNF-β were expressed almost throughout the early phase of virus infection with some variations. IL-2, IL-3, IL-4, IL-10, interferon (IFN)-γ, granulocyte/macrophage colony stimulating factor (GM-CSF), and IL-2 receptor (IL-2R) were mainly expressed by the infiltrating cells. TNF-α, TNF-β, and IL-1β were also expressed partly by the infiltrating cells. T-helper (Th)1-related cytokines (IL-2, IFN-γ, and TNF-β) were more strongly expressed than Th2-related cytokines (IL-4 and IL-10) in vivo, indicating that the Th cells which infiltrated the heart and mediated the immune responses in the early phase of acute myocarditis were mainly of Th1-type. © 1997 by John Wiley & Sons, Ltd.     

Molecular epidemiology of a coxsackievirus B3 outbreak.

An outbreak of coxsackievirus B3 infection occurred in South Africa in 1984 with a variety of clinical manifestations being observed. Fifty-one isolates from patients ranging in age from young babies to middle-aged adults were obtained. To define further the epidemiology of this outbreak all isolates were characterised by either 1- or 2-dimensional oligonucleotide mapping. One-dimensional mapping was found to be highly successful for initial screening of the isolates before further characterisation by 2-dimensional fingerprinting. All isolates were found to be essentially the same strain of coxsackievirus B3 although slight variations in both the 1- and 2-dimensional patterns could be observed. Some coxsackievirus B3 strains from geographically unrelated regions but isolated during the same time period as the outbreak showed clearly distinguishable oligonucleotide maps.     

Interferon-gamma-induced activation of nitric oxide-mediated antiviral activity of macrophages caused by a recombinant coxsackievirus B3

Cardiovascular disease is one of the major causes of human death and has been linked to many different risks including viral infections. Coxsackievirus B3 (CVB3) is one of the most important pathogens responsible for virus-induced myocarditis. Cytokines are normally involved in the control of CVB3 replication and pathogenesis. Among them, interferon-gamma (IFN-gamma) in particular is highly protective against CVB3. A novel strategy to circumvent virus-caused heart disease is based on the development of cytokine-expressing recombinant virus vectors. Using in vitro co-culture experiments, the release of IFN-gamma by the recombinant virus variant CVB3/IFN-gamma activates the expression of the inducible nitric oxide synthase (iNOS) in CVB3 non-susceptible murine macrophages and the release of nitric oxide (NO), which reduce coxsackieviral replication directly. In addition, the expression of IFN-gamma by CVB3/IFN-gamma contributes to protect mice from lethal infections by iNOS induction in murine peritoneal macrophages, viral load reduction, and pancreatic tissue protection.     

黄芪对心肌炎小鼠心肌穿孔素mRNA和CVB3m mRNA表达的影响

目的探讨黄芪注射液治疗小鼠柯萨奇B3(CVB3)病毒性心肌炎(VMC)的疗效及其机制。方法BALB/c小鼠24只腹腔感染柯萨奇病毒B3亲心肌细胞株(CVB3m)后,随机等分为两组:黄芪治疗组(黄芪注射液每天10g/kg腹腔注射)和对照组。实验第8天留取心肌,分别进行心肌病理检查,心肌穿孔素(perforin,PFP)mRNA和CVB3m mRNA逆转录多聚酶链反应(RT-PCR)分析,并对心肌组织PFP mRNA和CVB3m mRNA表达水平进行相关性分析。结果(1)心肌组织病理改变:黄芪治疗组明显轻于对照组;(2)心肌PFP mRNA表达水平RT-PCR半定量:黄芪治疗组心肌PFP mRNA的表达明显低于对照组(1.10±0.07与1.31±0.12,P<0.01);(3)心肌CVB3m mRNA表达水平RT-PCR半定量:黄芪治疗组心肌CVB3m mRNA表达明显低于对照组(1.07±0.04与1.18±0.02,P<0.01);(4)心肌PFP mRNA水平与CVB3mmRNA水平呈显著正相关(r=0.68,P<0.01)。结论PFP介导的细胞毒性作用在病毒性心肌炎的发病中起重要作用。黄芪对小鼠急性心肌炎模型中心肌组织CVB3m病毒复制有明显的抑制作用,心肌组织中PFP mRNA表达水平与心肌组织CVB3m mRNA的表达水平的变化具有同步性,黄芪对CVB3m诱导的小鼠急性心肌炎模型有显著的治疗作用。     

穿孔素和Fas配体在柯萨奇B3病毒性心肌炎小鼠心肌浸润细胞中表达

目的探讨穿孔素（ＰＦＰ）和Ｆａｓ配体（Ｌ）介导的细胞毒作用在病毒性心肌炎发病中的作用。方法将４０只ＢＡＬＢ／ｃ小鼠随机等分为实验组和对照组，分别用柯萨奇Ｂ３病毒（ＣＶＢ３）及不含病毒的病毒稀释液经腹腔接种，于接种后７天处死，取其心脏。应用免疫组化、逆转录－多聚酶链反应（ＲＴ－ＰＣＲ）和原位杂交等方法，检测细胞介导的细胞毒作用的主要效应分子ＰＦＰ和ＦａｓＬ在心肌浸润细胞中的表达。结果（１）实验组小鼠的心肌组织中均有ＰＦＰ和ＦａｓＬ抗原阳性细胞浸润，对照组则无；（２）ＲＴ－ＰＣＲ检测发现实验组鼠的心肌组织中ＰＦＰ和ＦａｓＬｍＲＮＡ的阳性率均为１００％，明显高于对照组的２０％和３０％（Ｐ均＜０．０１）；（３）原位杂交检查显示，实验组小鼠心肌组织中均可见ＰＦＰ和ＦａｓＬｍＲＮＡ阳性的浸润细胞，而对照组则均未发现。结论ＣＶＢ３小鼠心肌炎急性期，其心肌浸润细胞中有ＰＦＰ和ＦａｓＬ表达，提示它们在病毒性心肌炎发病机制中可能有重要作用     

Intrapulmonary cystic lymphangioma in a 2-month-old infant.

Lymphangioma is an abnormal collection of lymphatics that are developmentally isolated from the normal lymphatic system. Lymphangioma rarely presents as a solitary pulmonary lesion. We report a rare case of intrapulmonary cystic lymphangioma involving the upper lobe of the right lung, which presented with dyspnea in a 2-month-old infant. High-resolution computed tomography (HRCT) of the chest demonstrated a well-circumscribed, multiseptate, cystic lesion in the upper lobe of the right lung, mimicking the feature of type I congenital cystic adenomatoid mal-formation. The tumor was removed by bilobectomy of the upper and middle lobes of the right lung, and its pathologic examination confirmed the diagnosis of an intra-pulmonary cystic lymphangioma.     

Potentiation of coxsackievirus B3 infection in adult mice pretreated with a gold salt.

In mice treated with sodium aurothiomalate (myocrisin), prior to infection with Coxsackievirus B3, 90% of the animals died by the 11th day postinfection (p.i.). A mortality of 10% was noted in mice receiving myocrisin only, and no deaths occurred in animals infected with virus alone. The highest amount of virus was recovered from the pancreas of myocrisin-treated mice on day 3 p.i. This was over 500-fold higher than the virus titer found in the pancreas of mice infected with virus only. Generally the titer of virus present in different organs was higher at every point in drug-treated animals as compared to intact mice infected with the virus. A high and persistent viremia was present in myocrisin-treated mice; in contrast a low viremia followed by virus clearance from the blood was observed in intact mice infected with the virus. The antibody response was studied in intact and myocrisin-treated mice infected with the virus. In both groups, no neutralizing antibodies were detected on days 1, 2, and 3 p.i. On day 7 after infection, the titers of antibodies were 1:16 and 1:12 in intact and myocrisin-treated mice, respectively. Administration of hyperimmune anti-Coxsackievirus B3 serum 6 hours after infection protrected in myocrisin-treated group of mice against lethal disease. The results of these studies suggest that (1) antibodies alone may not be sufficient to limit the spread and persistence of virus in natural infections and (2) in the absence of any apparent histopathological differences the increased multiplication of Coxsackievirus B3 could be the cause of death in myocrisin-treated mice.     

A point mutation in VP1 of coxsackievirus B4 alters antigenicity

While coxsackievirus infections have been linked to several autoimmune diseases, very little is known about the immunogenicity of the coxsackieviruses. Using two genetically related variants of coxsackievirus B4, CB4-P and CB4-V, the relationship between virulence and antigenicity was examined. The virulent variant, CB4-V, was shown to be more antigenic than the avirulent CB4-P variant. The increased antigenicity of CB4-V was due to a single amino acid substitution in the VP1 capsid protein (a threonine residue at amino acid position 129), a site that had been previously identified as a major determinant of viral virulence. Thr-129 of VP1 is predicted to lie within a conformational B cell epitope. In addition, a nearby linear B cell epitope spanning residues 68 to 82 of VP1 was identified as a potential serotype-specific, neutralization antigenic site. The linear and conformational B cell epitopes of coxsackievirus B4 may be analogous to antigenic sites 1 and 1B of poliovirus. To address whether the increased antigenicity of CB4-V influenced the severity of disease, mouse strains that differ in their outcome to viral infection were analyzed. Mice that developed the most severe disease and succumbed to infection were more immunoresponsive than mice that survived infection with CB4-V. The data suggest that immune-mediated mechanisms play a role in the severity of CB4-V induced disease.     

柯萨奇B组3型病毒中国分离株VP4、3D基因序列及系统发生树分析

目的研究柯萨奇B组3型病毒（CVB3）中国分离株结构蛋白VP4、非结构蛋白3D基因序列及变异性。方法在HeLa细胞中增殖病毒，用RT-PCR扩增目的基因片段，与pMDl8-T载体连接，PCR初步鉴定后测序，进行序列同源性及系统发生分析。结果CVB3中国分离株VP4基因含207个碱基，编码69个氨基酸，与Nancy株氨基酸同源性为97．10％；3D基因含1386个碱基，编码462个氨基酸，与Nancy株氨基酸同源性为97．62％。在系统发生中，CVB3中国株VP4基因、3D基因均与Nancy株聚簇。结论CVB3中国分离株VP4和3D基因长度与Nancy株一致，进化上属同一分支。     

Nonspecific interstitial pneumonia and usual interstitial pneumonia with mutation in surfactant protein C in familial pulmonary fibrosis.

Nonspecific interstitial pneumonia, a recently described form of idiopathic interstitial pneumonia, is characterized by uniform involvement of the alveolar septae with interstitial inflammation and variable amounts of fibrosis. Histological observations differentiate nonspecific interstitial pneumonia from usual interstitial pneumonia and clinically, patients with a nonspecific interstitial pneumonia pattern show better prognosis than those with usual interstitial pneumonia. We have genetically analyzed a family with a history of usual interstitial pneumonia. Most of the patients presented as adults and their biopsies showed a pattern consistent with usual interstitial pneumonia. However, three family members presented in early childhood and their biopsies revealed a nonspecific interstitial pneumonia pattern. The inheritance pattern of usual interstitial pneumonia is consistent with autosomal dominant inheritance with variable expression. DNA sequence analyses of the surfactant protein C gene in children with nonspecific interstitial pneumonia and adults with usual interstitial pneumonia exhibit a common heterozygous mutation located in exon 5. The mutation causes a Leu188 to Gln188 change in the carboxy-terminal region of prosurfactant protein C, possibly affecting peptide processing. These observations suggest that individuals with this particular mutation in surfactant protein C gene might be at increased risk of interstitial lung disease of variety of types.     

Factors affecting the detection of enteroviruses in cerebrospinal fluid with coxsackievirus B3 and poliovirus 1 cDNA probes.

Enteroviruses are common pathogens of meningitis and encephalitis, and infections are often difficult to distinguish clinically from bacterial and herpetic infections of the central nervous system. An array of enteroviruses added to cerebrospinal fluid in reconstruction experiments were detected by a dot hybridization assay. Optimal handling and processing conditions for infected cerebrospinal fluid were established, and the effect on the hybridization reaction of humoral and cellular components of the inflammatory response was determined. Six hybridization probes, derived from poliovirus 1 and coxsackievirus B3, were then tested, singly and in combinations, to optimize the sensitivity and spectrum of the assay. Implications for enteroviral taxonomy based on these experiments are discussed.     

Treatment of coxsackievirus B3 myocarditis by immunoactive peptide in an animal model.

The effect of immunostimulant therapy on acute viral myocarditis, induced with coxsackievirus B3 (CB3), was investigated in C3H/He mice. Peritoneal exudate cells (PEC) or spleen cells (SC) from mice pretreated with a synthetic immunoactivating peptide FK565 significantly inhibited the multiplication of CB3 in C3H/He mouse embryo fibroblast cells compared with PEC or SC from nontreated mice in vitro (6.45 +/- 0.20 log10 PFU/ml; control: 6.85 +/- 0.05, P < 0.05; 6.40 +/- 0.07, control: 6.78 +/- 0.07, P < 0.05, respectively), although FK565 did not inhibit viral replication directly. Mice were inoculated intraperitoneally with 3 x 10(5) plaque-forming units of CB3. FK565, 1 or 10 micrograms/kg, given intraperitoneally daily started on the same day of viral inoculation. To determine CB3 virus titer, mice were killed on Day 3. To study survival and myocardial histopathology, mice were killed on Day 20. Histopathological findings were scored on a scale of 0 to 4. FK565, 10 micrograms/kg/day, effectively inhibited myocardial viral replication (3.23 +/- 0.42 log10 PFU/mg, control: 3.71 +/- 0.40, P < 0.05), reduced the cellular infiltration (1.3 +/- 0.7, control: 2.5 +/- 0.5, P < 0.05), myocardial necrosis (1.4 +/- 0.9, control: 3.0 +/- 0.6, P < 0.01), and calcification of the heart (1.0 +/- 0.6, control: 2.5 +/- 0.5, P < 0.01) and increased survival (60%, control: 30%, P < 0.05). The present study suggests that immunostimulant therapy improves the course of viral myocarditis during the viral-mediated phase. The inhibitory activity of FK565 seems to be due to the activation of host defense mechanisms.     

Coxsackie B3 myocarditis in 4 cases of suspected sudden infant death syndrome: diagnosis by immunohistochemical and molecular-pathologic investigations

Immunohistochemical and molecular-pathologic techniques have improved the diagnosis of myocarditis as compared with conventional histologic staining methods done according to the Dallas criteria. Most investigations were carried out on adults, and only a few authors investigating childhood deaths applied these modern methods, used for diagnosing myocarditis. We report on four children under one year of age, who suddenly died without prodromal symptoms. Their deaths were attributed to SIDS (sudden infant death syndrome). Immunohistochemical (LCA, CD68, CD45R0, MHC-class-II-molecules, VP1-capsid-protein of enteroviruses) and molecular-pathologic (RT-PCR) investigations, however, suggested that death was caused by a coxsackie-B3-myocarditis. In the future, these methods should be used for investigating cases with suspicion of SIDS.