Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally pre...Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.展开更多
Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for han...Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for hand, foot and mouth disease (HFMD) have been developed. Here we examined the potential of improving the vaccines by inserting the EV71 5’ untranslated region (5’ UTR) containing the full length internal ribosome entry site (IRES) sequence to the EV71 VP1-based DNA vaccine constructs. Four vaccine constructs designated as 5’ UTR-VP1/EGFP, VP1/EGFP, 5’ UTR-VP1/pVAX and VP1/pVAX, were designed using the pEGFP-N1 and pVAX-1 expression vectors, respectively. Transfection of Vero cells with the vaccine constructs with the 5’-UTR (5’-UTR-VP1/EGFP and 5’ UTR-VP1/pVAX) resulted in higher percentages of cells expressing the recombinant protein in comparison to cells transfected with vectors without the 5’-UTR (67% and 57%, respectively). Higher IgG responses (29%) were obtained from mice immunized with the DNA vaccine construct with the full length 5’ UTR. The same group of mice when challenged with life EV71 produced significantly higher neutralizing antibody (NAb) titers (>5-fold). These results suggest that insertion of the EV71 5’ UTR sequence consisting of the full length IRES to the EV71 DNA vaccine constructs improved the efficacy of the constructs with enhanced elicitation of the neutralizing antibody responses.展开更多
Hepatitis A virus(HAV)infection is still an important health issue worldwide.Although several effective HAV vaccines are available,it is difficult to perform universal vaccination in certain countries.Therefore,it may...Hepatitis A virus(HAV)infection is still an important health issue worldwide.Although several effective HAV vaccines are available,it is difficult to perform universal vaccination in certain countries.Therefore,it may be better to develop antivirals against HAV for the prevention of severe hepatitis A.We found that several drugs potentially inhibit HAV internal ribosomal entry site-dependent translation and HAV replication.Artificial intelligence and machine learning could also support screening of anti-HAV drugs,using drug repositioning and drug rescue approaches.展开更多
In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-...In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-independent manner by using a cis-regulatory element termed the internal ribosome entry site （IRES）. The first experimentally validated IRES was reported in the poliovirus （Pelletier and Sonenberg, 1988）. Then eukaryotic cellular mRNAs were also validated to contain IRES elements.展开更多
文摘Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.
文摘Recent improvement in the technologies for efficient delivery of DNA vaccines has renewed interest in the DNA-based vaccines. Several DNA-based vaccines against human enterovirus 71 (EV71), the causative agent for hand, foot and mouth disease (HFMD) have been developed. Here we examined the potential of improving the vaccines by inserting the EV71 5’ untranslated region (5’ UTR) containing the full length internal ribosome entry site (IRES) sequence to the EV71 VP1-based DNA vaccine constructs. Four vaccine constructs designated as 5’ UTR-VP1/EGFP, VP1/EGFP, 5’ UTR-VP1/pVAX and VP1/pVAX, were designed using the pEGFP-N1 and pVAX-1 expression vectors, respectively. Transfection of Vero cells with the vaccine constructs with the 5’-UTR (5’-UTR-VP1/EGFP and 5’ UTR-VP1/pVAX) resulted in higher percentages of cells expressing the recombinant protein in comparison to cells transfected with vectors without the 5’-UTR (67% and 57%, respectively). Higher IgG responses (29%) were obtained from mice immunized with the DNA vaccine construct with the full length 5’ UTR. The same group of mice when challenged with life EV71 produced significantly higher neutralizing antibody (NAb) titers (>5-fold). These results suggest that insertion of the EV71 5’ UTR sequence consisting of the full length IRES to the EV71 DNA vaccine constructs improved the efficacy of the constructs with enhanced elicitation of the neutralizing antibody responses.
基金Supported by The Japan Agency for Medical Research and Development,No.JP20fk0210075.
文摘Hepatitis A virus(HAV)infection is still an important health issue worldwide.Although several effective HAV vaccines are available,it is difficult to perform universal vaccination in certain countries.Therefore,it may be better to develop antivirals against HAV for the prevention of severe hepatitis A.We found that several drugs potentially inhibit HAV internal ribosomal entry site-dependent translation and HAV replication.Artificial intelligence and machine learning could also support screening of anti-HAV drugs,using drug repositioning and drug rescue approaches.
基金supported by the grants from National Natural Science Foundation of China (Nos. 61571223 and 61171191)
文摘In eukaryotic cells, initiation of protein translation is to recruit the ribosome to a specific mRNA, which is generally dependent on the 5＇ cap structure. However, protein translation can also be initiated in a cap-independent manner by using a cis-regulatory element termed the internal ribosome entry site （IRES）. The first experimentally validated IRES was reported in the poliovirus （Pelletier and Sonenberg, 1988）. Then eukaryotic cellular mRNAs were also validated to contain IRES elements.
