| 1. |
- Andersson, E, et al.
(författare)
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Near full-length HIV-1 genome sequencing in newly diagnosed individuals in Sweden
- 2019
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Ingår i: VIRUS EVOLUTION. - : Oxford University Press (OUP). - 2057-1577. ; 5, s. S2-S2
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Swedish HIV-1 epidemic is characterized by a high diversity in HIV subtypes and recombinants as a result of migration. To study the time from infection through viral diversification, transmission patterns, and drug resistance in minor quasispecies, a robust protocol for pan-genotypic near full-length HIV-1 genome (HIV-NFLG) next-generation sequencing (NGS) is key. Our group has established two protocols for HIV-NFLG on the Illumina platform that we aim to compare and, if necessary, modify to find a method with optimized coverage, depth, and subtype inclusivity. Zanini et al. (https://doi.org/10.7554/eLife.11282.001) have developed a method with one-step RT-PCR with six overlapping primer sets, followed by NGS and quality filtering and assembly with in-house methods. Aralaguppe et al. (https://doi.org/10.1016/j.jviromet.2016.07.010) have designed amplification in two fragments, followed by multiplexed NGS and quality control and assembly with Iterative Virus Assembler and VICUNA. Both methods have high coverage per nucleotide and low error rates in amplification and sequencing and can reliably identify SNPs at 1 per cent of the viral population with linkage within the quasispecies. Subtype inclusivity remains a challenge even though both methods show success in amplifying and sequencing subtypes B, C, and the common recombinants 01_AE and 02_AG. Therefore, we aim to evaluate and optimize our NFLG NGS methods on a panel of patient samples that more completely reflects HIV-1 diversity in Sweden. Patient samples from fifty treatment-naïve viremic individuals representing the genotypic HIV-1 panorama in Sweden, including CRFs, are being amplified and sequenced by both protocols. Coverage of the genome, error rate, and possible depth of quasispecies analysis is being evaluated. We will compare number of reads, coverage across the HIV genome, and representation of minor single nucleotide variants as well as subtype inclusivity and impact of plasma RNA levels. To do this we will use an in-house bioinformatic pipeline. The NFLG sequences will also be analyzed with phylogenetic tools for determination of subtypes including CRFs and URFs.
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| 2. |
- Bennedbaek, M., et al.
(författare)
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Phylogenetic analysis of HIV-1 shows frequent cross-country transmission and local population expansions
- 2021
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Ingår i: Virus Evolution. - : Oxford University Press (OUP). - 2057-1577. ; 7:2
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Tidskriftsartikel (refereegranskat)abstract
- Understanding of pandemics depends on the characterization of pathogen collections from well-defined and demographically diverse cohorts. Since its emergence in Congo almost a century ago, Human Immunodeficiency Virus Type 1 (HIV-1) has geographically spread and genetically diversified into distinct viral subtypes. Phylogenetic analysis can be used to reconstruct the ancestry of the virus to better understand the origin and distribution of subtypes. We sequenced two 3.6-kb amplicons of HIV-1 genomes from 3,197 participants in a clinical trial with consistent and uniform sampling at sites across 35 countries and analyzed our data with another 2,632 genomes that comprehensively reflect the HIV-1 genetic diversity. We used maximum likelihood phylogenetic analysis coupled with geographical information to infer the state of ancestors. The majority of our sequenced genomes (n=2,501) were either pure subtypes (A-D, F, and G) or CRF01_AE. The diversity and distribution of subtypes across geographical regions differed; USA showed the most homogenous subtype population, whereas African samples were most diverse. We delineated transmission of the four most prevalent subtypes in our dataset (A, B, C, and CRF01_AE), and our results suggest both continuous and frequent transmission of HIV-1 over country borders, as well as single transmission events being the seed of endemic population expansions. Overall, we show that coupling of genetic and geographical information of HIV-1 can be used to understand the origin and spread of pandemic pathogens.
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| 3. |
- Boswell, M. T., et al.
(författare)
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Intrahost evolution of the HIV-2 capsid correlates with progression to AIDS
- 2022
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Ingår i: Virus Evolution. - : Oxford University Press (OUP). - 2057-1577. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- HIV-2 infection will progress to AIDS in most patients without treatment, albeit at approximately half the rate of HIV-1 infection. HIV-2 capsid (p26) amino acid polymorphisms are associated with lower viral loads and enhanced processing of T cell epitopes, which may lead to protective Gag-specific T cell responses common in slower progressors. Lower virus evolutionary rates, and positive selection on conserved residues in HIV-2 env have been associated with slower progression to AIDS. In this study we analysed 369 heterochronous HIV-2 p26 sequences from 12 participants with a median age of 30 years at enrolment. CD4% change over time was used to stratify participants into relative faster and slower progressor groups. We analysed p26 sequence diversity evolution, measured site-specific selection pressures and evolutionary rates, and determined if these evolutionary parameters were associated with progression status. Faster progressors had lower CD4% and faster CD4% decline rates. Median pairwise sequence diversity was higher in faster progressors (5.7x10-3 versus 1.4x10-3 base substitutions per site, P<0.001). p26 evolved under negative selection in both groups (dN/dS=0.12). Median virus evolutionary rates were higher in faster than slower progressors – synonymous rates: 4.6x10-3 vs. 2.3x10-3; and nonsynonymous rates: 6.9x10-4 vs. 2.7x10-4 substitutions/site/year, respectively. Virus evolutionary rates correlated negatively with CD4% change rates (ρ = -0.8, P=0.02), but not CD4% level. The signature amino acid at p26 positions 6, 12 and 119 differed between faster (6A, 12I, 119A) and slower (6G, 12V, 119P) progressors. These amino acid positions clustered near to the TRIM5α/p26 hexamer interface surface. p26 evolutionary rates were associated with progression to AIDS and were mostly driven by synonymous substitutions. Nonsynonymous evolutionary rates were an order of magnitude lower than synonymous rates, with limited amino acid sequence evolution over time within hosts. These results indicate HIV-2 p26 may be an attractive therapeutic target.
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| 4. |
- Chang, Wei-Shan, et al.
(författare)
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Novel hepatitis D-like agents in vertebrates and invertebrates
- 2019
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Ingår i: Virus Evolution. - : OXFORD UNIV PRESS. - 2057-1577. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis delta virus (HDV) is the smallest known RNA virus, encoding a single protein. Until recently, HDV had only been identified in humans, where it is strongly associated with co-infection with hepatitis B virus (HBV). However, the recent discovery of HDV-like viruses in metagenomic samples from birds and snakes suggests that this virus has a far longer evolutionary history. Herein, using additional meta-transcriptomic data, we show that highly divergent HDV-like viruses are also present in fish, amphibians, and invertebrates, with PCR and Sanger sequencing confirming the presence of the invertebrate HDV-like viruses. Notably, the novel viruses identified here share genomic features characteristic of HDV, such as a circular genome of only approximately 1.7 kb in length, and self-complementary, unbranched rod-like structures. Coiled-coil domains, leucine zippers, conserved residues with essential biological functions, and isoelectronic points similar to those in the human hepatitis delta virus antigens (HDAgs) were also identified in the putative non-human viruses. Importantly, none of these novel HDV-like viruses were associated with hepadnavirus infection, supporting the idea that the HDV-HBV association may be specific to humans. Collectively, these data not only broaden our understanding of the diversity and host range of HDV, but also shed light on its origin and evolutionary history.
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| 5. |
- de Klerk, A, et al.
(författare)
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Conserved recombination patterns across coronavirus subgenera
- 2022
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Ingår i: Virus evolution. - : Oxford University Press (OUP). - 2057-1577. ; 8:2, s. veac054-
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Tidskriftsartikel (refereegranskat)abstract
- Recombination contributes to the genetic diversity found in coronaviruses and is known to be a prominent mechanism whereby they evolve. It is apparent, both from controlled experiments and in genome sequences sampled from nature, that patterns of recombination in coronaviruses are non-random and that this is likely attributable to a combination of sequence features that favour the occurrence of recombination break points at specific genomic sites, and selection disfavouring the survival of recombinants within which favourable intra-genome interactions have been disrupted. Here we leverage available whole-genome sequence data for six coronavirus subgenera to identify specific patterns of recombination that are conserved between multiple subgenera and then identify the likely factors that underlie these conserved patterns. Specifically, we confirm the non-randomness of recombination break points across all six tested coronavirus subgenera, locate conserved recombination hot- and cold-spots, and determine that the locations of transcriptional regulatory sequences are likely major determinants of conserved recombination break-point hotspot locations. We find that while the locations of recombination break points are not uniformly associated with degrees of nucleotide sequence conservation, they display significant tendencies in multiple coronavirus subgenera to occur in low guanine-cytosine content genome regions, in non-coding regions, at the edges of genes, and at sites within the Spike gene that are predicted to be minimally disruptive of Spike protein folding. While it is apparent that sequence features such as transcriptional regulatory sequences are likely major determinants of where the template-switching events that yield recombination break points most commonly occur, it is evident that selection against misfolded recombinant proteins also strongly impacts observable recombination break-point distributions in coronavirus genomes sampled from nature.
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| 6. |
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| 7. |
- Esbjornsson, J., et al.
(författare)
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HIV-1 transmission between MSM and heterosexuals, and increasing proportions of circulating recombinant forms in the Nordic Countries
- 2016
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Ingår i: Virus Evolution. - : Oxford University Press (OUP). - 2057-1577. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Increased knowledge about HIV-1 transmission dynamics in different transmission groups and geographical regions is fundamental for assessing and designing prevention efforts against HIV-1 spread. Since the first reported cases of HIV infection during the early 1980s, the HIV-1 epidemic in the Nordic countries has been dominated by HIV-1 subtype B and MSM transmission. HIV-1 pol sequences and clinical data of 51 per cent of all newly diagnosed HIV-1 infections in Sweden, Denmark, and Finland in the period 2000-2012 (N = 3,802) were analysed together with a large reference sequence dataset (N = 4,537) by trend analysis and phylogenetics. Analysis of the eight dominating subtypes and CRFs in the Nordic countries (A, B, C, D, G, CRF01_AE, CRF02_AG, and CRF06_cpx) showed that the subtype B proportion decreased while the CRF proportion increased over the study period. A majority (57 per cent) of the Nordic sequences formed transmission clusters, with evidence of mixing both geographically and between transmission groups. Detailed analyses showed multiple occasions of transmissions from MSM to heterosexuals and that active transmission clusters more often involved single than multiple Nordic countries. The strongest geographical link was between Denmark and Sweden. Finally, Denmark had a larger proportion of heterosexual domestic spread of HIV-1 subtype B (75 per cent) compared with Sweden (49 per cent) and Finland (57 per cent). We describe different HIV-1 transmission patterns between countries and transmission groups in a large geographical region. Our results may have implications for public health interventions in targeting HIV-1 transmission networks and identifying where to introduce such interventions.
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| 8. |
- Gaunt, Michael W., et al.
(författare)
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Widespread interspecific phylogenetic tree incongruence between mosquito-borne and insect-specific flaviviruses at hotspots originally identified in Zika virus
- 2022
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Ingår i: Virus Evolution. - : Oxford University Press (OUP). - 2057-1577. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Intraspecies (homologous) phylogenetic incongruence, or 'tree conflict' between different loci within the same genome of mosquito-borne flaviviruses (MBFV), was first identified in dengue virus (DENV) and subsequently in Japanese encephalitis virus (JEV), St Louis encephalitis virus, and Zika virus (ZIKV). Recently, the first evidence of phylogenetic incongruence between interspecific members of the MBFV was reported in ZIKV and its close relative, Spondweni virus. Uniquely, these hybrid proteomes were derived from four incongruent trees involving an Aedes-associated DENV node (1 tree) and three different Culex-associated flavivirus nodes (3 trees). This analysis has now been extended across a wider spectrum of viruses within the MBFV lineage targeting the breakpoints between phylogenetic incongruent loci originally identified in ZIKV. Interspecies phylogenetic incongruence at these breakpoints was identified in 10 of 50 viruses within the MBFV lineage, representing emergent Aedes and Culex-associated viruses including JEV, West Nile virus, yellow fever virus, and insect-specific viruses. Thus, interspecies phylogenetic incongruence is widespread amongst the flaviviruses and is robustly associated with the specific breakpoints that coincide with the interspecific phylogenetic incongruence previously identified, inferring they are 'hotspots'. The incongruence amongst the emergent MBFV group was restricted to viruses within their respective associated epidemiological boundaries. This MBFV group was RY-coded at the third codon position ('wobble codon') to remove transition saturation. The resulting 'wobble codon' trees presented a single topology for the entire genome that lacked any robust evidence of phylogenetic incongruence between loci. Phylogenetic interspecific incongruence was therefore observed for exactly the same loci between amino acid and the RY-coded 'wobble codon' alignments and this incongruence represented either a major part, or the entire genomes. Maximum likelihood codon analysis revealed positive selection for the incongruent lineages. Positive selection could result in the same locus producing two opposing trees. These analyses for the clinically important MBFV suggest that robust interspecific phylogenetic incongruence resulted from amino acid selection. Convergent or parallel evolutions are evolutionary processes that would explain the observation, whilst interspecific recombination is unlikely.
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| 9. |
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| 10. |
- Henningsson, R., et al.
(författare)
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Disseqt-distribution-based modeling of sequence space time dynamics
- 2019
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Ingår i: Virus Evolution. - : Oxford University Press (OUP). - 2057-1577. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Rapidly evolving microbes are a challenge to model because of the volatile, complex, and dynamic nature of their populations. We developed the DISSEQT pipeline (DIStribution-based SEQuence space Time dynamics) for analyzing, visualizing, and predicting the evolution of heterogeneous biological populations in multidimensional genetic space, suited for population-based modeling of deep sequencing and high-throughput data. The pipeline is openly available on GitHub (https://github.com/rasmushenningsson/DISSEQT.jl, accessed 23 June 2019) and Synapse (https://www.synapse.org/#!Synapse: syn11425758, accessed 23 June 2019), covering the entire workflow from read alignment to visualization of results. Our pipeline is centered around robust dimension and model reduction algorithms for analysis of genotypic data with additional capabilities for including phenotypic features to explore dynamic genotype-phenotype maps. We illustrate its utility and capacity with examples from evolving RNA virus populations, which present one of the highest degrees of genetic heterogeneity within a given population found in nature. Using our pipeline, we empirically reconstruct the evolutionary trajectories of evolving populations in sequence space and genotype-phenotype fitness landscapes. We show that while sequence space is vastly multidimensional, the relevant genetic space of evolving microbial populations is of intrinsically low dimension. In addition, evolutionary trajectories of these populations can be faithfully monitored to identify the key minority genotypes contributing most to evolution. Finally, we show that empirical fitness landscapes, when reconstructed to include minority variants, can predict phenotype from genotype with high accuracy.
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