AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in vari...AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeA g-negative and HBeA g-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/m L, the HBX 5' end region [nucleotide(nt) 1255-1611] was PCRamplified and submitted to next-generation sequencing(NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes) obtained by NGS. Conservation at the HBx protein amino acid(aa) level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample(2487-9279, IQR 2817). In 14/27 patients(51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region(nt 1255-1286) and the other in the 5' end coding region(nt 1519-1603). This last region coded for a conserved amino acid region(aa 63-76) that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.展开更多
Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, res...Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3 G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype.CONCLUSION The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.展开更多
BACKGROUND Since it is currently not possible to eradicate hepatitis B virus(HBV)infection with existing treatments,research continues to uncover new therapeutic strategies.HBV core protein,encoded by the HBV core gen...BACKGROUND Since it is currently not possible to eradicate hepatitis B virus(HBV)infection with existing treatments,research continues to uncover new therapeutic strategies.HBV core protein,encoded by the HBV core gene(HBC),intervenes in both structural and functional processes,and is a key protein in the HBV life cycle.For this reason,both the protein and the gene could be valuable targets for new therapeutic and diagnostic strategies.Moreover,alterations in the protein sequence could serve as potential markers of disease progression.AIM To detect,by next-generation sequencing,HBC hyper-conserved regions that could potentially be prognostic factors and targets for new therapies.METHODS Thirty-eight of 45 patients with chronic HBV initially selected were included and grouped according to liver disease stage[chronic hepatitis B infection without liver damage(CHB,n=16),liver cirrhosis(LC,n=5),and hepatocellular carcinoma(HCC,n=17)].HBV DNA was extracted from patients’plasma.A region between nucleotide(nt)1863 and 2483,which includes HBC,was amplified and analyzed by next-generation sequencing(Illumina Mi Seq platform).Sequences were genotyped by distance-based discriminant analysis.General and intergroup nt and amino acid(aa)conservation was determined by sliding window analysis.The presence of nt insertion and deletions and/or aa substitutions in the different groups was determined by aligning the sequences with genotype-specific consensus sequences.RESULTS Three nt(nt 1900-1929,2249-2284,2364-2398)and 2 aa(aa 117-120,159-167)hyper-conserved regions were shared by all the clinical groups.All groups showed a similar pattern of conservation,except for five nt regions(nt 1946-1992,2060-2095,2145-2175,2230-2250,2270-2293)and one aa region(aa 140-160),where CHB and LC,respectively,were less conserved(P<0.05).Some group-specific conserved regions were also observed at both nt(2306-2334 in CHB and 1935-1976 and 2402-2435 in LC)and aa(between aa 98-103 in CHB and 28-30 and 51-54 in LC)levels.No differences in insertion and deletions frequencies were observed.An aa substitution(P79 Q)was observed in the HCC group with a median(interquartile range)frequency of 15.82(0-78.88)vs 0(0-0)in the other groups(P<0.05 vs CHB group).CONCLUSION The differentially conserved HBC and HBV core protein regions and the P79 Q substitution could be involved in disease progression.The hyper-conserved regions detected could be targets for future therapeutic and diagnostic strategies.展开更多
基金Supported by the Instituto de Salud Carlos III,No.PI15/00856the European Regional Development Fund(ERDF),No.PI15/00856
文摘AIM To detect hyper-conserved regions in the hepatitis B virus(HBV) X gene(HBX) 5' region that could be candidates for gene therapy.METHODS The study included 27 chronic hepatitis B treatmentnaive patients in various clinical stages(from chronic infection to cirrhosis and hepatocellular carcinoma, both HBeA g-negative and HBeA g-positive), and infected with HBV genotypes A-F and H. In a serum sample from each patient with viremia > 3.5 log IU/m L, the HBX 5' end region [nucleotide(nt) 1255-1611] was PCRamplified and submitted to next-generation sequencing(NGS). We assessed genotype variants by phylogenetic analysis, and evaluated conservation of this region by calculating the information content of each nucleotide position in a multiple alignment of all unique sequences(haplotypes) obtained by NGS. Conservation at the HBx protein amino acid(aa) level was also analyzed.RESULTS NGS yielded 1333069 sequences from the 27 samples, with a median of 4578 sequences/sample(2487-9279, IQR 2817). In 14/27 patients(51.8%), phylogenetic analysis of viral nucleotide haplotypes showed a complex mixture of genotypic variants. Analysis of the information content in the haplotype multiple alignments detected 2 hyper-conserved nucleotide regions, one in the HBX upstream non-coding region(nt 1255-1286) and the other in the 5' end coding region(nt 1519-1603). This last region coded for a conserved amino acid region(aa 63-76) that partially overlaps a Kunitz-like domain.CONCLUSION Two hyper-conserved regions detected in the HBX 5' end may be of value for targeted gene therapy, regardless of the patients' clinical stage or HBV genotype.
基金Supported by the Instituto de Salud Carlos Ⅲ,grants PI15/00856 and PI17/02233co-financed by the European Regional Development Fund(ERDF)
文摘Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, IQR 1.11-4.57 vs CHD 8.87, 6.56-11.18, P = 0.038). There were no significant differences in the functional indices, but CI and CHD patients also showed a trend towards greater complexity than CHB. No differences were found for any HBV quasispecies complexity indices between CHD and CI patients. G-to-A and C-to-T nucleotide changes, characteristic of APOBEC3 G, were higher in CHD and CI than in CHB in genotype A haplotypes, but not in genotype D. The proportion of nt G-to-A vs A-to-G changes and C-to-T vs T-to-C changes in genotype A and D haplotypes in CHD patients showed no significant differences. In CHB and CI the results of these comparisons were dependent on HBV genotype.CONCLUSION The lower-replication CHD and CI groups show a trend to higher quasispecies complexity than the higher-replication CHB group. The mechanisms associated with this greater complexity require elucidation.
基金Supported by the Instituto de Salud CarlosⅢ,Spain,the European Regional Development Fund,No.PI18/01436。
文摘BACKGROUND Since it is currently not possible to eradicate hepatitis B virus(HBV)infection with existing treatments,research continues to uncover new therapeutic strategies.HBV core protein,encoded by the HBV core gene(HBC),intervenes in both structural and functional processes,and is a key protein in the HBV life cycle.For this reason,both the protein and the gene could be valuable targets for new therapeutic and diagnostic strategies.Moreover,alterations in the protein sequence could serve as potential markers of disease progression.AIM To detect,by next-generation sequencing,HBC hyper-conserved regions that could potentially be prognostic factors and targets for new therapies.METHODS Thirty-eight of 45 patients with chronic HBV initially selected were included and grouped according to liver disease stage[chronic hepatitis B infection without liver damage(CHB,n=16),liver cirrhosis(LC,n=5),and hepatocellular carcinoma(HCC,n=17)].HBV DNA was extracted from patients’plasma.A region between nucleotide(nt)1863 and 2483,which includes HBC,was amplified and analyzed by next-generation sequencing(Illumina Mi Seq platform).Sequences were genotyped by distance-based discriminant analysis.General and intergroup nt and amino acid(aa)conservation was determined by sliding window analysis.The presence of nt insertion and deletions and/or aa substitutions in the different groups was determined by aligning the sequences with genotype-specific consensus sequences.RESULTS Three nt(nt 1900-1929,2249-2284,2364-2398)and 2 aa(aa 117-120,159-167)hyper-conserved regions were shared by all the clinical groups.All groups showed a similar pattern of conservation,except for five nt regions(nt 1946-1992,2060-2095,2145-2175,2230-2250,2270-2293)and one aa region(aa 140-160),where CHB and LC,respectively,were less conserved(P<0.05).Some group-specific conserved regions were also observed at both nt(2306-2334 in CHB and 1935-1976 and 2402-2435 in LC)and aa(between aa 98-103 in CHB and 28-30 and 51-54 in LC)levels.No differences in insertion and deletions frequencies were observed.An aa substitution(P79 Q)was observed in the HCC group with a median(interquartile range)frequency of 15.82(0-78.88)vs 0(0-0)in the other groups(P<0.05 vs CHB group).CONCLUSION The differentially conserved HBC and HBV core protein regions and the P79 Q substitution could be involved in disease progression.The hyper-conserved regions detected could be targets for future therapeutic and diagnostic strategies.
