Shiga toxin B-subunit （STxB） from Shigella dysenteriae targets in vivo antigen to cancer cells, dendritic cells （DC） and B cells, which preferentially express the globotriaosylceramide （Gb3） receptor. This pivot...Shiga toxin B-subunit （STxB） from Shigella dysenteriae targets in vivo antigen to cancer cells, dendritic cells （DC） and B cells, which preferentially express the globotriaosylceramide （Gb3） receptor. This pivotal role has encouraged scientists to investigate fusing STxB with other clinical antigens. Due to the challenges of obtaining a functional soluble form of the recombinant STxB, such as formation of inclusion bodies during protein expression, scientists tend to combine STxB with vaccine candidates rather than using their genetically fused forms. In this work, we fused HPV16 E7 as a vaccine candidate to the recombinantly-produced STxB. To minimize the formation of inclusion bodies, we investigated a number of conditions during the expression procedure. Then various strategies were used in order to obtain high yield of soluble recombinant protein from E. coli which included the use of different host strains, reduction of cultivation temperature, as well as using different concentrations of IPTG and different additives （Glycin, Triton X-100, ZnC12）. Our study demonstrated the importance of optimizing incubation parameters for recombinant protein expression in E. coli; also showed that the secretion production can be achieved over the course of a few hours when using additives such as glycine and Triton X-100. Interestingly, it was shown that when the culture mediums were supplemented by additives, there was an inverse ratio between time of induction （TOI） and the level of secreted protein at lower temperatures. This study determines the optimal conditions for high yield soluble E7-STxB expression and subsequently facilitates reaching a functionally soluble form of STxB-based vaccines, which can be considered as a potent vaccine candidate for cervical cancer.展开更多
OBJECTIVE:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.METHODS:Eighty healthy Wistar male rats were randomized into eight groups(n=10 rats each):Norm...OBJECTIVE:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.METHODS:Eighty healthy Wistar male rats were randomized into eight groups(n=10 rats each):Normal group,Asthma model group,Dexamethasone group,Guilong Kechuanning group,Xiaoqinglong Decoction group,and Pingchuanning Decoction low-,middle-,and high-dose groups.The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin.All treatments were administered at the first stimulation of asthma onset(third week of modeling),and the rats were killed after stimulating asthma attacks for 4 weeks.The general conditions of rats and pathomorphological changes of the lung tissues were observed.The expression of nerve growth factor(NGF) of the lung tissues was measured with immunohistochemical methods,and the content of Clara cell secretory protein(CCSP) mRNA was determined with RT-PCR.RESULTS:Compared with the Normal group,the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed(P<0.01).Compared with the Model group,the indices of Pingchuanning Decoction and other treatment groups were improved to some extent(P<0.05 or P<0.01).CONCLUSIONS:Pathological changes of airway inflammation and remodeling were present in these rat asthma models.Pingchuanning Decoction had an intervention effect on these experimental models.Its functional mechanism may be related to multiple factors,including alleviation of airway inflammation,relief of bronchial smooth muscle spasm,and inhibition of airway remodeling.展开更多
基金supported by Research Council of Shiraz University of Medical Sciences (91-01-36-4417), Shiraz, Iran
文摘Shiga toxin B-subunit （STxB） from Shigella dysenteriae targets in vivo antigen to cancer cells, dendritic cells （DC） and B cells, which preferentially express the globotriaosylceramide （Gb3） receptor. This pivotal role has encouraged scientists to investigate fusing STxB with other clinical antigens. Due to the challenges of obtaining a functional soluble form of the recombinant STxB, such as formation of inclusion bodies during protein expression, scientists tend to combine STxB with vaccine candidates rather than using their genetically fused forms. In this work, we fused HPV16 E7 as a vaccine candidate to the recombinantly-produced STxB. To minimize the formation of inclusion bodies, we investigated a number of conditions during the expression procedure. Then various strategies were used in order to obtain high yield of soluble recombinant protein from E. coli which included the use of different host strains, reduction of cultivation temperature, as well as using different concentrations of IPTG and different additives （Glycin, Triton X-100, ZnC12）. Our study demonstrated the importance of optimizing incubation parameters for recombinant protein expression in E. coli; also showed that the secretion production can be achieved over the course of a few hours when using additives such as glycine and Triton X-100. Interestingly, it was shown that when the culture mediums were supplemented by additives, there was an inverse ratio between time of induction （TOI） and the level of secreted protein at lower temperatures. This study determines the optimal conditions for high yield soluble E7-STxB expression and subsequently facilitates reaching a functionally soluble form of STxB-based vaccines, which can be considered as a potent vaccine candidate for cervical cancer.
基金Supported by the National Natural Science Fund(No. 81173187)the Natural Science Fund of Anhui Province (No.11040606M217)
文摘OBJECTIVE:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.METHODS:Eighty healthy Wistar male rats were randomized into eight groups(n=10 rats each):Normal group,Asthma model group,Dexamethasone group,Guilong Kechuanning group,Xiaoqinglong Decoction group,and Pingchuanning Decoction low-,middle-,and high-dose groups.The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin.All treatments were administered at the first stimulation of asthma onset(third week of modeling),and the rats were killed after stimulating asthma attacks for 4 weeks.The general conditions of rats and pathomorphological changes of the lung tissues were observed.The expression of nerve growth factor(NGF) of the lung tissues was measured with immunohistochemical methods,and the content of Clara cell secretory protein(CCSP) mRNA was determined with RT-PCR.RESULTS:Compared with the Normal group,the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed(P<0.01).Compared with the Model group,the indices of Pingchuanning Decoction and other treatment groups were improved to some extent(P<0.05 or P<0.01).CONCLUSIONS:Pathological changes of airway inflammation and remodeling were present in these rat asthma models.Pingchuanning Decoction had an intervention effect on these experimental models.Its functional mechanism may be related to multiple factors,including alleviation of airway inflammation,relief of bronchial smooth muscle spasm,and inhibition of airway remodeling.
