Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC)....Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.展开更多
AIM: To design and construct an exogenous multiple epitope of helper T lymphocytes (HTL), and to evaluate its effect on anti-HBs response through DNA immunization. METHODS: Artificial HTL epitope, PADRE and four other...AIM: To design and construct an exogenous multiple epitope of helper T lymphocytes (HTL), and to evaluate its effect on anti-HBs response through DNA immunization. METHODS: Artificial HTL epitope, PADRE and four other HTL epitopes from different proteins were linked together using splicing by overlap extension to generate exogenous multiple epitopes of HTL, MTE5. pcMTE5 and pcHB were generated by cloning MTE5 and fragments of HBV pre-S2/S gene into mammalian expression plasmid pcDNA3. Four chimeric plasmids were constructed by cloning MTE5 into the region of pre-S2 gene (Barn HI), 5' terminal of S gene (HincII, Xba I) and 3' terminal of S gene (Acc I) of pcHB respectively. BALB/c mice were used in DNA immunization of the recombinant plasmids. Anti-HBs was detected using Abbott IMx AUSAB test kits.RESULTS: The sequences of MTE5 and the 6 constructs ofrecombinant plasmids were confirmed to be correct by DNA sequencing. The anti-HBs response of the coinoculation of pcHB and pcMTE5 was much higher than that of the inoculation of pcHB only (136.7+69.1 mIU/mL vs 27.6+17.3 mIU/mL, P<0.01, t =-6.56). Among the 4 chimeric plasmids, only the plasmid in which MTE5 was inserted into the pre-S2 region had good anti-HBs response (57.54±7.68 mIU/mL), and had no significant difference compared with those of pcHB and the co-inoculation of pcHB and pcMTE5. CONCLUSION: Exogenous multiple epitopes of HTL had immune enhancement when they were co-inoculated with pre-S2/S gene or inoculated in the chimeric form at a proper site of pre-S2/S gene of HBV. It might suggest that it was possible to improve hepatitis B vaccine using exogenous multiple epitopes of HTL. The antibody responses were very low using DNA immunization in the study. Thus, the immune enhancement effect of exogenous multiple epitopes of HTL has to be confirmed and the effect on overcoming the drawback of the polymorphism of HLA II antigens should also be evaluated after these chimeric plasmids are expressed in mammalian cell lines.展开更多
Extensive structure-activity relationships(SARs)study of JND3229 was conducted to yield a series of new reve rsible 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidine privileged scaffold as EGFRC797 S inhibitors.One of the mo...Extensive structure-activity relationships(SARs)study of JND3229 was conducted to yield a series of new reve rsible 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidine privileged scaffold as EGFRC797 S inhibitors.One of the most potent compound 6 i potently suppressed EGFRL858 R/T790 M/C797 S kinase with an IC50 value of 3.1 nmol/L,and inhibited the proliferation of BaF3 cells harboring EGFRL858 R/T790 M/C797 S and EGFR19 D/T790 M/C797 S mutants with IC50 values of 290 nmol/L and 316 nmol/L,respectively.Further,6 i dose-dependently induced suppression of the phosphorylation of EGFRL858 R/T790 M/C797 S and EGFR19 D/T790 M/C797 S in BaF3 cells.Compound 6 i may serve as a promising lead compound for further drug discovery overcoming the acquired resistance of non-small cell lung cancer(NSCLC)patients.展开更多
基金Supported by the grant from the National Science Council(NSC 96-2320-B-030-004-MY3),Executive Yuan,Taiwan
文摘Chronic hepatitis B is a global health problem. The clinical outcomes of chronic hepatitis B infection include asymptomatic carrier state, chronic hepatitis(CH), liver cirrhosis(LC), and hepatocellular carcinoma(HCC). Because of the spontaneous error rate inherent to viral reverse transcriptase, the hepatitis B virus(HBV) genome evolves during the course of infection under the antiviral pressure of host immunity. The clinical significance of pre-S/S variants has become increasingly recognized in patients with chronic HBV infection. Pre-S/S variants are often identified in hepatitis B carriers with CH, LC, and HCC, which suggests that these naturally occurring pre-S/S variants may contribute to the development of progressive liver damage and hepatocarcinogenesis. This paper reviews the function of the pre-S/S region along with recent findings related to the role of pre-S/S variants in liver diseases. According to the mutation type, five pre-S/S variants have been identified: pre-S deletion, pre-S point mutation, pre-S1 splice variant, C-terminus S point mutation, and pre-S/S nonsense mutation. Their associations with HBV genotype and the possible pathogenesis of pre-S/S variants are discussed. Different pre-S/S variants cause liver diseases through different mechanisms. Most cause the intracellular retention of HBV envelope proteins and induction of endoplasmic reticulum stress, which results in liver diseases. Pre-S/S variants should be routinely determined in HBV carriers to help identify individuals who may be at a high risk of less favorable liver disease progression. Additional investigations are required to explore the molecular mechanisms of the pre-S/S variants involved in the pathogenesis of each stage of liver disease.
基金Supported by the National Natural Science Foundation of China,NO.39970677 and the Science Foundation of Guangdong Province,NO.99M04801G
文摘AIM: To design and construct an exogenous multiple epitope of helper T lymphocytes (HTL), and to evaluate its effect on anti-HBs response through DNA immunization. METHODS: Artificial HTL epitope, PADRE and four other HTL epitopes from different proteins were linked together using splicing by overlap extension to generate exogenous multiple epitopes of HTL, MTE5. pcMTE5 and pcHB were generated by cloning MTE5 and fragments of HBV pre-S2/S gene into mammalian expression plasmid pcDNA3. Four chimeric plasmids were constructed by cloning MTE5 into the region of pre-S2 gene (Barn HI), 5' terminal of S gene (HincII, Xba I) and 3' terminal of S gene (Acc I) of pcHB respectively. BALB/c mice were used in DNA immunization of the recombinant plasmids. Anti-HBs was detected using Abbott IMx AUSAB test kits.RESULTS: The sequences of MTE5 and the 6 constructs ofrecombinant plasmids were confirmed to be correct by DNA sequencing. The anti-HBs response of the coinoculation of pcHB and pcMTE5 was much higher than that of the inoculation of pcHB only (136.7+69.1 mIU/mL vs 27.6+17.3 mIU/mL, P<0.01, t =-6.56). Among the 4 chimeric plasmids, only the plasmid in which MTE5 was inserted into the pre-S2 region had good anti-HBs response (57.54±7.68 mIU/mL), and had no significant difference compared with those of pcHB and the co-inoculation of pcHB and pcMTE5. CONCLUSION: Exogenous multiple epitopes of HTL had immune enhancement when they were co-inoculated with pre-S2/S gene or inoculated in the chimeric form at a proper site of pre-S2/S gene of HBV. It might suggest that it was possible to improve hepatitis B vaccine using exogenous multiple epitopes of HTL. The antibody responses were very low using DNA immunization in the study. Thus, the immune enhancement effect of exogenous multiple epitopes of HTL has to be confirmed and the effect on overcoming the drawback of the polymorphism of HLA II antigens should also be evaluated after these chimeric plasmids are expressed in mammalian cell lines.
基金financial support from the National Natural Science Foundation of China(Nos.81922062,81874285 and 81673285)Guangdong International Science and TechnologyCooperation Project(No.2018A050506043)+1 种基金Guangzhou City Key Laboratory of Precision Chemical Drug Development(No.201805010007)Institutes for Drug Discovery and Development of Chinese Academy of Science(No.CASIMM0120185006)。
文摘Extensive structure-activity relationships(SARs)study of JND3229 was conducted to yield a series of new reve rsible 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidine privileged scaffold as EGFRC797 S inhibitors.One of the most potent compound 6 i potently suppressed EGFRL858 R/T790 M/C797 S kinase with an IC50 value of 3.1 nmol/L,and inhibited the proliferation of BaF3 cells harboring EGFRL858 R/T790 M/C797 S and EGFR19 D/T790 M/C797 S mutants with IC50 values of 290 nmol/L and 316 nmol/L,respectively.Further,6 i dose-dependently induced suppression of the phosphorylation of EGFRL858 R/T790 M/C797 S and EGFR19 D/T790 M/C797 S in BaF3 cells.Compound 6 i may serve as a promising lead compound for further drug discovery overcoming the acquired resistance of non-small cell lung cancer(NSCLC)patients.
