SARS患者血清IL-8、IL-12和TGF-β1的检测及意义

目的 :探讨SARS患者血清IL 8、IL 12和TGF β1在SARS冠状病毒感染致病中的作用。 方法 :应用酶联免疫吸附法 (ELISA)测定广州地区 2 8例SARS冠状病毒感染患者双份血清IL 8、IL 12和TGF β1的水平。实验数据采用两样本均数t检验法。结果 :2 8例SARS冠状病毒感染者血清IL 8水平、病程第 2周IL 12水平比正常健康对照组明显降低 (P <0 0 5 )。SARS冠状病毒感染者血清TGF β1水平与对照组比较无明显差异 (P >0 0 5 )。 结论 :IL 8和IL 12在SARS冠状病毒的致病与免疫过程中可能起降低细胞免疫功能作用     

The intracellular sites of early replication and budding of SARS-coronavirus

In this study, we analyzed the replication and budding sites of severe acute respiratory syndrome coronavirus (SARS-CoV) at early time points of infection. We detected cytoplasmic accumulations containing the viral nucleocapsid protein, viral RNA and the non-structural protein nsp3. Using EM techniques, we found that these putative viral replication sites were associated with characteristic membrane tubules and double membrane vesicles that most probably originated from ER cisternae. In addition to its presence at the replication sites, N also accumulated in the Golgi region and colocalized with the viral spike protein. Immuno-EM revealed that budding occurred at membranes of the ERGIC (ER-Golgi intermediate compartment) and the Golgi region as early as 3 h post infection, demonstrating that SARS-CoV replicates surprisingly fast. Our data suggest that SARS-CoV establishes replication complexes at ER-derived membranes. Later on, viral nucleocapsids have to be transported to the budding sites in the Golgi region where the viral glycoproteins accumulate and particle formation occurs.     

Domestic poultry and SARS coronavirus, southern China

SARS coronavirus injected intratracheally into chickens, turkeys, geese, ducks, and quail, or into the allantoic sac of their embryonating eggs, failed to cause disease or replicate. This finding suggests that domestic poultry were unlikely to have been the reservoir, or associated with dissemination, of SARS coronavirus in the animal markets of southern China.     

SARS患者7年随访血清抗体变化规律及胃肠道免疫组化研究

目的 连续7年随访严重急性呼吸综合征(SARS)患者血清特异性IgM、IgG及N蛋白抗体滴度变化,应用胃肠镜观察胃肠道的病理改变并进行免疫组织化学研究.方法 应用免疫荧光(IFA)和双抗原夹心ELISA方法,对SARS患者发病1年后采用每隔1年检测一次血清SARS病毒(SARS-CoV)特异性IgM、IgG及N蛋白抗体滴度;用抗SARS-CoV N蛋白单克隆抗体对SARS恢复期患者胃肠道组织进行免疫组化研究.结果 14例SARS患者特异性IgG抗体1年后平均滴度为1/71(95%CI:1/58～1/85),连续追踪7年呈下降趋势,7年后大部分患者IgG抗体滴度消失,特异性IgM抗体1年后消失,N蛋白抗体1年后平均滴度为1/146(95%CI:1/122～1/171),与IgG抗体变化同时呈下降趋势.7年后其中9例患者检测N蛋白抗体全部为阴性,另5例临床症状较重的患者,N蛋白抗体仍检测阳性,其中3例N蛋白抗体滴度维持在1/156～1/210之间,2例N蛋白抗体滴度接近正常.该5例患者行胃肠镜检测和细胞免疫组化试验,血中N蛋白抗体检测阳性的3例患者胃组织黏液腺上皮细胞免疫组化呈阳性表达,大部呈胞浆着色.其中1例患者在肠组织浆液柱状上皮及间质细胞亦有表达,另2例血清N蛋白抗体检测接近正常的患者,细胞免疫组化为阴性.5例患者病理活检:1例明确诊断为"胃印戒细胞癌并直肠多发转移"、1例"胃息肉"、1例"浅表性胃窦炎",其余2例正常.结论 SARS患者血清特异性IgM、IgG、N蛋白抗体在恢复期呈下降趋势,7年后大部分消失;N蛋白抗体变化规律与病情轻重程度有关.     

SARS-CoV感染者血清IFN-γ和TNF-α的动态变化及其意义

目的　探讨SARS患者血清IFN γ和TNF α在SARS冠状病毒感染免疫中的作用。方法　应用酶联免疫吸附法 (ELISA)测定广州地区 2 8例SARS冠状病毒感染患者双份血清IFN γ和TNF α的水平。实验数据采用两样本均数t检验法。结果　 2 8例SARS冠状病毒感染者急性期血清IFN γ和TNF α水平比正常健康对照组明显增高 (P <0 .0 5 ) ;恢复期血清IFN γ水平比正常健康对照组明显增高 (P <0 .0 5 )。感染病程第 1周 ,患者血清IFN γ水平达高峰 ,然后逐渐下降。SARS患者血清TNF α水平在病程第 2周达高峰 ,然后逐渐下降。结论　IFN γ和TNF α在SARS冠状病毒的致病与免疫过程中可能起重要作用     

SARS灭活疫苗毒种特性和效力试验方法的研究和建立

目的 验证SARS灭活疫苗生产用毒种和建立疫苗效力试验方法和评价疫苗有效性的方法和初步标准。方法 将SARS灭活疫苗进行系列稀释后免疫小鼠、原液疫苗免疫家兔，用异株病毒作为攻击毒以蚀斑减少法测定血清中和抗体，并与一组SARS病人恢复期血清的中和抗体水平进行比较。初步建立疫苗的效力试验方法和评价标准。结果 疫苗以不同稀释度免疫小鼠，能产生随不同稀释度疫苗相应梯度的中和抗体滴度。用原倍疫苗免疫的小鼠血清中和抗体可达495．2；原倍疫苗免疫家兔所产生的中和抗体GNT为55．0～79．9。无论是小鼠或家兔所产生的中和抗体对广东分离的病毒均较北京分离的病毒为高。南北不同区域的SARS病人恢复期血清中和抗体GMT为50．12～54．95，且发现北方人群样本的抗体高于南方人群样本。结论 用小鼠和家兔作疫苗的效力试验模型具有较好的敏感性和重复性，且产生的抗体水平较高：选用的攻击病毒对多批用不同毒株生产的疫苗免疫后的动物抗体具有较高的一致性，可用于评价疫苗的效力。     

Amotosalen photochemical inactivation of severe acute respiratory syndrome coronavirus in human platelet concentrates

A novel human coronavirus causing severe acute respiratory syndrome (SARS) emerged in epidemic form in early 2003 in China and spread worldwide in a few months. Every newly emerging human pathogen is of concern for the safety of the blood supply during and after an epidemic crisis. For this purpose, we have evaluated the inactivation of SARS-coronavirus (CoV) in platelet concentrates using an approved pathogen inactivation device, the INTERCEPT Blood System. Apheresis platelet concentrates (APCs) were inoculated with approximately 10(6) pfu mL(-1) of either Urbani or HSR1 isolates of SARS-CoV. The inoculated units were mixed with 150 microm amotosalen and illuminated with 3 J cm(-2) UV-A light. The viral titres were determined by plaque formation in Vero E6 cells. Mixing SARS-CoV with APC in the absence of any treatment decreased viral infectivity by approximately 0.5-1 log10. Following photochemical treatment, SARS-CoV was consistently inactivated to the limit of detection in seven independent APC units. No infectious virus was detected after treatment when up to one-third of the APC unit was assayed, demonstrating a mean log10-reduction of >6.2. Potent inactivation of SARS-CoV therefore extends the capability of the INTERCEPT Blood System in inactivating a broad spectrum of human pathogens including recently emerging respiratory viruses.     

RNA interference and antiviral therapy

RNA interference (RNAi) is an evolutionally conserved gene silencing mechanism present in a variety of eukaryotic species. RNAi uses short double-stranded RNA (dsRNA) to trigger degradation or translation repression of homologous RNA targets in a sequence-specific manner. This system can be induced effectively in vitro and in vivo by direct application of small interfering RNAs (siRNAs), or by expression of short hairpin RNA (shRNA) with non-viral and viral vectors. To date, RNAi has been extensively used as a novel and effective tool for functional genomic studies, and has displayed great potential in treating human diseases, including human genetic and acquired disorders such as cancer and viral infections. In the present review, we focus on the recent development in the use of RNAi in the prevention and treatment of viral infections. The mechanisms, strategies, hurdles and prospects of employing RNAi in the pharmaceutical industry are also discussed.