Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected.
Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum.
Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024.
Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.

Recombinant adeno-associated virus (rAAV) serotype 2, 3 and 8 vectors are the most promising liver-tropic AAV serotype vectors. Liver diseases are signiifcant problems in China. However, to date, few studies on AAV neutralizing antibodies (Nabs) were working with the Chinese population or with the rAAV3 vectors. The present study aimed to determine the prevalence of Nabs in Chinese population against wild-type AAV2, AAV3 and AAV8 capsids as wel as additional two AAV3 variants. In addition, we performed a preliminary analysis to investigate the potential inlfuence of traditional Chinese medicine body constitutions on AAV Nabs. Our work demonstrated that the majority of healthy Chinese subjects were positive for AAV Nabs, with the order of AAV2 > AAV3 = AAVLK03 > AAV8. There was no difference between: 1) AAV3 and its variants; 2) male and female subjects; and 3) different age cohorts (≤ 35, 36–50, and ≥ 51 years old). People in the Qi-deifciency constitution had signiifcantly increased AAV8 Nabs than people in the Gentleness constitution. Our studies may have impact on the future clinical design of AAV-based gene therapy in the Chinese population.

干扰素中和性抗体研究进展

干扰素(interferon,IFN)是机体免疫细胞分泌的一种细胞因子,是一种广谱抗病毒剂,它并不直接杀伤或抑制病毒,而主要是通过细胞表面受体作用使细胞产生抗病毒蛋白,从而抑制乙肝病毒的复制.同时它还可增强自然杀伤细胞(NK细胞)、巨噬细胞和T淋巴细胞的活力,起到免疫调节作用,并增强抗病毒能力.70年代中期人们发现慢性乙型肝炎患者自身产生干扰素的能力低下,在应用外源性干扰素后,不仅产生了上述抗病毒作用,同时还增加了肝细胞膜上人白细胞组织相容性抗原的密度,促进T细胞溶解感染性肝细胞的效能.临床上将干扰素用于治疗慢性乙肝和急慢性丙型肝炎已有20余年,其疗效已得到广泛的认可.研究显示,成人注射(2～5)×106单位干扰素后,3 h血清中干扰素活性开始测出,6 h达高峰,48 h基本消失.