人类疱疹病毒6型包膜胆固醇去除及糖蛋白表达

目的 探讨人类疱疹病毒(HHV)-6型包膜胆固醇去除后,对其包膜糖蛋白表达水平的影响。方法 用0,1,2,3,5,10 mmol/L不同浓度的甲基-β-环糊精作用于HHV-6A GS株,经20%蔗糖缓冲液梯度离心,去除甲基-β-环糊精,并纯化病毒,采用胆固醇含量检测试剂盒测定病毒胆固醇含量;纯化后的病毒感染HSB-2细胞后,用免疫蛋白杂交方法检测包膜糖蛋白的表达。结果 不同浓度的甲基-β-环糊精作用HHV-6A后,其包膜胆固醇含量与甲基-β-环糊精的浓度呈负相关,从35μg/ml下降到10μg/ml以下;与未经处理的病毒比较,其包膜糖蛋白的表达水平未发生改变,糖蛋白gQ1和gL的表达均处在同一水平。结论 甲基-β-环糊精可去除HHV-6A包膜胆固醇,且包膜胆固醇的缺失并未影响包膜糖蛋白的表达。     

用PCR技术检测健康孕妇人类疱疹病毒-6型潜伏感染

为了解健康孕妇中人类疱疹病毒-6型(HHV-6)的潜伏感染状况,1996年采用PCR技术,对济南市36例健康孕妇的外周血白细胞进行了HHV-6 DNA的检测.有7例检出HHV-6DNA,阳性率为19.4%.表明济南市健康孕妇中存在HHV-6潜伏感染.     

菲律宾菌素对人类疱疹病毒-6型感染性的影响

[目的]了解菲律宾菌素减少人类疱疹病毒-6型包膜胆固醇后,对病毒感染性的影响。[方法]用不同浓度的菲律宾菌素作用于HHV-6A GS株,经20%蔗糖缓冲液梯度离心,去除菲律宾菌素并纯化病毒,分别感染HSB-2和Jurkat细胞,然后采用IFA法、Hoechst 33258核染色及免疫蛋白杂交等方法检测病毒受菲律宾菌素作用后,其对靶细胞的融合、进入的影响。[结果]菲律宾菌素能减少HHV-6A包膜胆固醇,病毒的感染性及诱导细胞融合的能力显著减弱。[结论]HHV-6A包膜胆固醇在细胞融合过程中起着重要作用,同时也是病毒进入宿主细胞的关键因素。     

Absence of antibodies to human herpesvirus-6 in patients with slowly-progressive human immunodeficiency virus type I infection

To evaluate a possible role for Human Herpesvirus-type 6 (HHV-6) coinfection as a co-factor in the progression of HIV-1 disease, we investigated the prevalence of seropositivity for HHV-6 in a cohort of HIV-1 infected patients. These patients were retrospectively divided into two groups according to the decline of CD4+ T cells during the follow up: 11 were classified as rapid decliners (< 400 CD4+/cmm within 1 year), and 38 as slow decliners (> 400 CD4+/cmm after at least 4 years' follow up). HHV-6 antibodies were detected by a commercial immunofluorescence assay and by a Western blotting assay developed in our laboratory. Our results show that Western blot appears to provide results satisfactorily free of false positivities. We found that the frequency of HHV-6 seropositivity was significantly lower in the group of slow decliners, compared both to rapid decliners and to the general population. These data suggest a role for HHV-6 co-infection in the progression of HIV-1 disease.     

Human herpesviruses 6 and 7 and central nervous system infection in children

The role and frequency of human herpesviruses (HHV)-6 and -7 in central nervous system (CNS) diseases of children are unclear. Cerebrospinal fluid samples from 245 pediatric patients (median age 43 days), submitted for evaluations of possible sepsis or of neurologic symptoms, were tested for HHV-6 and HHV-7 DNA by polymerase chain reaction. HHV-6 DNA was found in 3 of 245 samples, and HHV-7 was found in 0 of 245 samples. The three patients with HHV-6 DNA were <2 months of age. HHV-6 was likely pathogenic in two patients with meningitis who lacked evidence of another microbiologic cause. HHV-6 and HHV-7 are uncommon causes of CNS infection in children. HHV-6 may occasionally cause meningitis in young infants.     

Mucosal immunization of calves with recombinant bovine adenovirus-3 coexpressing truncated form of bovine herpesvirus-1 gD and bovine IL-6

Previous studies have suggested an important role of the cytokine adjuvant IL-6 in the induction of mucosal immune responses in animals, including mice. Here, we report the in vivo ability of bovine adenovirus (BAdV)-3 expressing bovine (Bo) IL-6, to influence the systemic and mucosal immune responses against bovine herpesvirus (BHV)-1 gDt in calves. To co-express both antigen and cytokine, we first constructed a recombinant BAdV-3 expressing chimeric gDt.BoIL-6 protein (BAV326). Secondly, we constructed another recombinant BAdV-3 simultaneously expressing gDt and BoIL-6 using IRES containing a bicistronic cassette gDt-IRES.IL-6, (BAV327). Recombinant proteins expressed by BAV326 and BAV327 retained antigenicity (gDt) and biological activity (BoIL-6). Intranasal immunization of calves with recombinant BAV326, BAV327 or BAV308 (gDt alone) resulted in demonstrable levels of gDt-specific IgG responses in sera and IgA response in nasal secretions, in all animals. In addition, all calves developed complement-independent neutralizing antibody responses against BHV-1. However, no significant difference could be observed in the induction of systemic or mucosal immune response in animals immunized with recombinant BAV326 or BAV327 co-expressing BoIL-6. Moreover, there was no difference in the protection against BHV-1 challenge particularly in the amount of virus excretion in the nasal cavity in calves immunized with BAV326, BAV327 or BAV308. These data suggest that the BoIL-6 had no modulating effect on the induction of gDt specific mucosal and systemic immune responses in calves.     

Dietary lipid intake influences the level of cholesterol bound to haemoglobin in human erythrocytes

BACKGROUND: Blood cholesterol levels are affected by diet and in particular by the type of fat intake. We originally showed that a significant but variable amount of cholesterol is firmly bound to haemoglobin (Hb) yielding the Hb-lipid adduct (Hb-Ch) in erythrocytes isolated from normo-lipidemic males. AIM OF THE STUDY: To establish whether dietary lipids affect the level of Hb-Ch in human erythrocytes. METHODS: Seventy-four healthy free-living adults were separated according to their serum cholesterol levels into two groups: normo-cholesterolemic (LDL cholesterol <3.4 mmol/l and total cholesterol <5.2 mmol/l) (NC) and hyper-cholesterolemic (LDL cholesterol >or=3.4 mmol/l) (HC). Habitual dietary information was used to classify subjects in both study groups into sub-groups of low-fat (30% total energy as fat). The NC low-fat consumers were placed on a high-lipid (high-fat and high-cholesterol) diet whereas the HC subjects with high-fat intake were assigned to a low-lipid (low-fat and low-cholesterol) diet. Both types of dietary intervention were allowed to continue for 6 weeks. The main variable under scrutiny was the Hb-Ch concentration. RESULTS: In both study groups low-fat intake subjects had low levels of Hb-Ch (approx. 0.35 mmol/l RBC) compared with high-fat intake subjects (approx. 0.60 mmol/l RBC), and serum cholesterol was not correlated with Hb-Ch. The two dietary interventions produced substantial changes in the Hb-Ch level that paralleled variation in the serum cholesterol concentration. A high-lipid diet (35% fat, 15% saturated; 580 mg cholesterol) increased Hb-Ch (by approximately 47%, P<0.001) in subjects with low Hb-Ch at onset, whereas a low-lipid diet (28% fat, 9% saturated; 280 mg cholesterol) decreased Hb-Ch (by approximately 40%, P<0.001) in subjects with high Hb-Ch at onset. CONCLUSION: High consumption of dietary lipids, including saturated fat and cholesterol, has an important influence on the level of Hb-Ch in human erythrocytes.     

Antigenicity of hepatitis C virus envelope proteins expressed in Chinese hamster ovary cells

A putative second envelope glycoprotein (E2) of hepatitis C virus (HCV) was constitutively produced in a Chinese hamster ovary cell line stably transformed with a plasmid expressing E2 protein under the control of an exogenous promoter and a signal sequence. E2 protein that lacked part of the C-terminal hydrophobic region was glycosylated with high-mannose type oligosaccharides and retained in the cells. On the other hand, E2 protein lacking the entire C-terminal hydrophobic region was glycosylated with complex type oligosaccharides (complex form) and excreted into the culture medium. Immunoreactivity of the high-mannose and complex forms of E2 proteins against sera from HCV infected patients were analyzed. We found that the antigenicity of the complex form of E2 protein was greater than that of the high-mannose form of E2 protein. This result indicated that the complex form of the E2 protein is superior for use in diagnosing HCV infection.     

Serum IgG antibodies to human herpesvirus-6 (HHV-6) do not predict the progression of HIV disease to AIDS

Objectives: To evaluate if different levels of human herpesvirus 6 (HHV-6) antibodies can predict HIV disease progression. Design: Longitudinal study of individuals with a documented date of HIV seroconversion. Setting: Clinical centers located throughout Italy. Patients: Individuals who serconverted for HIV between 1983 and 1995 in Italy. Methods: Sera were tested for IgG antibodies to HHV-6 using a commercial enzyme immunoassay. A serum sample with an optical density (OD) 242 (i.e. the mean value of 10 negative controls+ 4×standard deviation) was considered as HHV-6 positive; the progression of HIV disease was evaluated estimating the relative hazards (RH) of AIDS (by Cox models) for individuals with higher levels vs. lower levels of HHV-6 antibodies or considering levels of antibodies based on 10% increase of the distribution (deciles). Rates of CD4 decline fitting linear regression were also estimated. Results: A total of 381 persons were followed for a median time of 4 years (range: 0.15–9 years) following the date of collection of the serum sample. The median OD value of HHV-6 antibodies was 306, with an interquartile range of 241–440 and a range of 48–2330. A slight inverse correlation was found between HHV-6 antibody levels and age of the individual at the time of serum collection (Spearman rank correlation coefficient, –0.16; p = 0.0013). No association was found between HHV-6 and CD4 level or between HHV-6 and CD8 level at the date of serum collection. The unadjusted RH of progression to AIDS was 0.63 (95% CI: 0.42–0.96) for HHV-6 positive individuals vs. HHV-6 negative; when adjusting for possible confounders (CD4, age, pre-AIDS HIV-related pathologies at the date of sera collection, and previous anti-herpes treatment), the RH of AIDS increased to 0.80 (95% CI: 0.51–1.23). No particular association with HIV disease progression was found when using the deciles of the distribution of HHV-6 antibodies. The median CD4 cell loss was 5.0 × 106 cells/l per month among HHV-6 positive individuals and 5.7 × 106 cells/l per month among the others. Conclusions: The presence of high levels of HHV-6 antibodies does not seem to predict the clinical or immunologic progression of HIV disease.     

大豆蛋白对人体血浆胆固醇的影响及机制探讨

目的观察大豆蛋白对正常人体血浆胆固醇浓度的影响并探讨其作用机制。方法选择健康大学生30名，男女各半，按血浆总胆固醇浓度、体重和性别均衡的原则，分为3组，在统一食谱、集中就餐的基础上，每天分别另外摄入30g酪蛋白，30g大豆分离蛋白，30g酪蛋白加880mg钙，共14d。实验开始和结束时．测量身高和体重：采血，测定血浆总胆固醇浓度。实验结束前，收集3d粪便，测定粪脂肪、钙、磷、镁和胆汁酸的排出量。结果(1)同实验开始时比，酪蛋白组血浆胆固醇浓度显著升高，而大豆蛋白组和酪蛋白加钙组血浆胆固醇浓度升高不明显。(2)同酪蛋白组比，大豆蛋白组粪钙、磷和镁的排出量均显著增加；粪脂肪和胆汁酸排出量分别增加33．6％和45．3％。(3)粪胆汁酸排出量与粪钙、磷、镁和脂肪的排出量呈显著性正相关。血浆胆固醇浓度随粪胆汁酸排出量增加呈下降的趋势。结论大豆蛋白降低血浆胆固醇浓度的机制可能是由于增加粪胆汁酸的排出量而导致肝脏中由胆固醇合成胆汁酸的增加，从而使血浆胆固醇浓度下降。     

全球禽流感流行概况及研究现状

目的 构建含有H6N2型禽流感病毒血凝素蛋白（HA）的疱疹口炎病毒（VSV）。 方法 以H6N2亚型禽流感病毒互补脱氧核糖核酸（cDNA）为模板,扩增HA基因,并与pcDNA3.1 + 载体连接;使用VSVΔG*-G病毒感染制备VSVΔG*-HA假病毒,并对其血凝活性进行测定。 结果 成功构建重组表达载体pcDNA3.1HA;HA蛋白表达于293T细胞;荧光显微镜证实VSVΔG*-HA假病毒包装成功;活性试验显示VSVΔG*-HA假病毒具有与禽流感病毒相似的血凝活性。 结论 含有H6N2型禽流感病毒HA蛋白的VSV假病毒安全、可靠,为进一步对禽流感病毒受体等研究及筛选抗流感病毒的药物提供了技术支持和思路。