AIM: Cytotoxin-associated protein (antigen) A (CagA) plays an important role in Helicobacter pylori(H pylori) pathogenesis.Our aim was to obtain cagA mutant strains by a new mutation method so as to better understand ...AIM: Cytotoxin-associated protein (antigen) A (CagA) plays an important role in Helicobacter pylori(H pylori) pathogenesis.Our aim was to obtain cagA mutant strains by a new mutation method so as to better understand the mechanism of CagA in epithelial cells. METHODS: In contrast with the traditional method using suicide plasmid,we constructed cagA- mutant strains directly with PCR products. The constructed mutant clones grew on selective media and allelic exchange was confirmed by Southern blot. Furthermore, two different transformation methods, electroporation, and natural transformation, were compared with regard to the efficiency of recombination. RESULTS:The mutation by PCR products could be completed within 3-5 d, and the recombination rate by electroporation and natural transformation was 4.02×10-8 and 1.03×10-9 respectively. Mutation rate by electroporation (4.02×10-8) was far higher than by natural transformation (1.03×10-9) (P= 0.000<0.005). CONCLUSION: cagA- mutant strains have been constructed, which is important for further study on the function of CagA in epithelial cells.A mutation method by directly using PCR products has been proved successful with a much higher mutation rate, and is easier,especially when in combination with electroporation.This method could be widely used in gene deletion of H pylori.展开更多
Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2.The prevalence of HSV is worldwide.It primarily infects humans through epithelial cells,when it introduces a latent in...Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2.The prevalence of HSV is worldwide.It primarily infects humans through epithelial cells,when it introduces a latent infection into the nervous system.During viral latency,only a region known as the latency-associated transcript (LAT) is expressed.The discovery of HSV miRNAs helps to draw a larger picture of the infection and pathogenesis of the virus.This review summarizes miRNAs found in HSV-1 and HSV-2 so far.The functional studies of miRNAs in HSV to date indicate that they play a stage-specific role coordinated with viral proteins to maintain the virus life cycle.展开更多
基金Supported by the National Natural Science Foundation, No.30370078
文摘AIM: Cytotoxin-associated protein (antigen) A (CagA) plays an important role in Helicobacter pylori(H pylori) pathogenesis.Our aim was to obtain cagA mutant strains by a new mutation method so as to better understand the mechanism of CagA in epithelial cells. METHODS: In contrast with the traditional method using suicide plasmid,we constructed cagA- mutant strains directly with PCR products. The constructed mutant clones grew on selective media and allelic exchange was confirmed by Southern blot. Furthermore, two different transformation methods, electroporation, and natural transformation, were compared with regard to the efficiency of recombination. RESULTS:The mutation by PCR products could be completed within 3-5 d, and the recombination rate by electroporation and natural transformation was 4.02×10-8 and 1.03×10-9 respectively. Mutation rate by electroporation (4.02×10-8) was far higher than by natural transformation (1.03×10-9) (P= 0.000<0.005). CONCLUSION: cagA- mutant strains have been constructed, which is important for further study on the function of CagA in epithelial cells.A mutation method by directly using PCR products has been proved successful with a much higher mutation rate, and is easier,especially when in combination with electroporation.This method could be widely used in gene deletion of H pylori.
基金supported by the National Natural Sciences Foundation of China(No.30670094 and 30700028)Youth Science Research Foundation of PUMC(No.2012X23)
文摘Herpes simplex virus (HSV) is a group of common human pathogens with two serotypes HSV-1 and HSV-2.The prevalence of HSV is worldwide.It primarily infects humans through epithelial cells,when it introduces a latent infection into the nervous system.During viral latency,only a region known as the latency-associated transcript (LAT) is expressed.The discovery of HSV miRNAs helps to draw a larger picture of the infection and pathogenesis of the virus.This review summarizes miRNAs found in HSV-1 and HSV-2 so far.The functional studies of miRNAs in HSV to date indicate that they play a stage-specific role coordinated with viral proteins to maintain the virus life cycle.
