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 o...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.展开更多
OBJECTIVE The aim of this research was to clone and express the antigen of the previously prepared monoclonal antibody named M4G3. METHODS Western blots were used to screen a breast cancer cell line that overexpresses...OBJECTIVE The aim of this research was to clone and express the antigen of the previously prepared monoclonal antibody named M4G3. METHODS Western blots were used to screen a breast cancer cell line that overexpresses the M4G3-associated antigen. A λ, zap cDNA expression library of breast cancer cells was constructed and screened using M4G3 as a probe to clone the antigen. The positive clones were subcloned and identified by homologous comparison using BLAST. RESULTS The λ zap cDNA expression library had 1.0×10^6 independent clones. Fifteen positive clones were isolated following 3 rounds of immunoscreening and identified as being from Mycoplasma pulmonis. CONCLUSION The specific antigen that matched the monoclonal M4G3 antibody is an unknown protein of M. pulmonis. This work is helpful for the further study of the association of M. pulmonis infection with breast cancer.展开更多
Influenza virus can rapidly change its antigenicity, via mutation in the hemagglutinin(HA) protein, to evade host immunity. The emergence of the novel human-infecting avian H7N9 virus in China has caused widespread co...Influenza virus can rapidly change its antigenicity, via mutation in the hemagglutinin(HA) protein, to evade host immunity. The emergence of the novel human-infecting avian H7N9 virus in China has caused widespread concern. However, evolution of the antigenicity of this virus is not well understood. Here, we inferred the antigenic epitopes of the HA protein from all H7 viruses, based on the five well-characterized HA epitopes of the human H3N2 virus. By comparing the two major H7 phylogenetic lineages, i.e., the Eurasian lineage and the North American lineage, we found that epitopes A and B are more frequently mutated in the Eurasian lineage, while epitopes B and C are more frequently mutated in the North American lineage. Furthermore, we found that the novel H7N9 virus(derived from the Eurasian lineage) isolated in China in the year 2013, contains six frequently mutated sites on epitopes that include site 135, which is located in the receptor binding domain. This indicates that the novel H7N9 virus that infects human may already have been subjected to gradual immune pressure and receptor-binding variation. Our results not only provide insights into the antigenic evolution of the H7 virus but may also help in the selection of suitable vaccine strains.展开更多
基金RFCID, No 01030152, RGC, CUHK4428/06M, ITF ITS091/03 of Hong Kong Government, and Faculty Direct Fund of the Chinese University of Hong Kong
文摘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.
基金This work was supported by the National Natural Science Foundation of China （No.30370553）.
文摘OBJECTIVE The aim of this research was to clone and express the antigen of the previously prepared monoclonal antibody named M4G3. METHODS Western blots were used to screen a breast cancer cell line that overexpresses the M4G3-associated antigen. A λ, zap cDNA expression library of breast cancer cells was constructed and screened using M4G3 as a probe to clone the antigen. The positive clones were subcloned and identified by homologous comparison using BLAST. RESULTS The λ zap cDNA expression library had 1.0×10^6 independent clones. Fifteen positive clones were isolated following 3 rounds of immunoscreening and identified as being from Mycoplasma pulmonis. CONCLUSION The specific antigen that matched the monoclonal M4G3 antibody is an unknown protein of M. pulmonis. This work is helpful for the further study of the association of M. pulmonis infection with breast cancer.
基金supported by the National Basic Research Program of China(2015CB910501)the Major National Earmark Project for Infectious Diseases(2014ZX10004002-001)+1 种基金the Key Research Program of the Chinese Academy of Sciences(KJZD-EW-L09-1-2)to Jiang Tai Jiaothe National Natural Science Foundation of China(31470273)to Wu Ai Ping
文摘Influenza virus can rapidly change its antigenicity, via mutation in the hemagglutinin(HA) protein, to evade host immunity. The emergence of the novel human-infecting avian H7N9 virus in China has caused widespread concern. However, evolution of the antigenicity of this virus is not well understood. Here, we inferred the antigenic epitopes of the HA protein from all H7 viruses, based on the five well-characterized HA epitopes of the human H3N2 virus. By comparing the two major H7 phylogenetic lineages, i.e., the Eurasian lineage and the North American lineage, we found that epitopes A and B are more frequently mutated in the Eurasian lineage, while epitopes B and C are more frequently mutated in the North American lineage. Furthermore, we found that the novel H7N9 virus(derived from the Eurasian lineage) isolated in China in the year 2013, contains six frequently mutated sites on epitopes that include site 135, which is located in the receptor binding domain. This indicates that the novel H7N9 virus that infects human may already have been subjected to gradual immune pressure and receptor-binding variation. Our results not only provide insights into the antigenic evolution of the H7 virus but may also help in the selection of suitable vaccine strains.
