| 1. |
- Gupta, S, et al.
(författare)
-
Performance of genotypic tools for prediction of tropism in HIV-1 subtype C V3 loop sequences
- 2015
-
Ingår i: Intervirology. - : S. Karger AG. - 1423-0100 .- 0300-5526. ; 58:1, s. 1-5
-
Tidskriftsartikel (refereegranskat)abstract
- Currently, there is no consensus on the genotypic tools to be used for tropism analysis in HIV-1 subtype C strains. Thus, the aim of the study was to evaluate the performance of the different V3 loop-based genotypic algorithms available. We compiled a dataset of 645 HIV-1 subtype C V3 loop sequences of known coreceptor phenotypes (531 R5-tropic/non-syncytium-inducing and 114 X4-tropic/R5X4-tropic/syncytium-inducing sequences) from the Los Alamos database (http://www.hiv.lanl.gov/) and previously published literature. Coreceptor usage was predicted based on this dataset using different software-based machine-learning algorithms as well as simple classical rules. All the sophisticated machine-learning methods showed a good concordance of above 85%. Geno2Pheno (false-positive rate cutoff of 5-15%) and CoRSeqV3-C were found to have a high predicting capability in determining both HIV-1 subtype C X4-tropic and R5-tropic strains. The current sophisticated genotypic tropism tools based on V3 loop perform well for tropism prediction in HIV-1 subtype C strains and can be used in clinical settings.
|
|
| 2. |
- Hulstrom, AL, et al.
(författare)
-
Human natural killer cells in asymptomatic human immunodeficiency virus-1 infection
- 2000
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 43:4-6, s. 294-301
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Objectives:</i> We evaluated whether DNA immunization with HIV-1 regulatory genes change natural killer (NK) effector cell activity. NK cells are the most important cells for the immediate host defense against virus-infected and tumor cells. We analyzed the NK activities of HIV-1-infected individuals against K562 cells (the classical assay) as well as against a CD4+ cell line with and without HIV-1 infection. CD4+ T lymphocytes are the main target cells for HIV-1 infection in vivo. Various proportions of the CD4+ T lymphocyte population carry the HIV-1 genome, produce virus and contribute to the systemic spread of HIV-1. <i>Methods:</i> CD4+ cell lines were established through HTLV-1 transformation which made the cells susceptible to NK lysis. NK activity was then tested in a <sup>51</sup>Cr release assay. <i>Results:</i> NK cells of asymptomatic HIV-infected individuals mediated considerable lytic activity against K562 cells as well as against the uninfected and HIV-1-infected CD4+ cell line, and so did the NK cells of HIV-1-infected patients on highly active antiretroviral treatment. <i>Conclusion:</i> DNA immunization with HIV-1-regulatory genes did not significantly change the NK effector cell activity.
|
|
| 3. |
- Isaguliants, MG, et al.
(författare)
-
DNA-encoding enzymatically active HIV-1 reverse transcriptase, but not the inactive mutant, confers resistance to experimental HIV-1 challenge
- 2000
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 43:4-6, s. 288-293
-
Tidskriftsartikel (refereegranskat)abstract
- The present study was undertaken to examine the immunogenicity of a single plasmid DNA representing the reverse transcriptase (RT) of HIV-1. Plasmids containing the enzymatically active RT as well as a mutated nonenzymatically active RT with nucleotide (nt)-binding motifs of YMDD and YMLL, respectively, were used to immunize mice. Both constructs induced similar good antibody and T cell responses, with a tendency towards antibody directed to peptides representing the active and mutated sites. Immunized mice were challenged with a murine pseudotype HIV-1/MuLV infected spleen cells. Seven out of 10 mice immunized with RT had no recoverable HIV-1, while 10 individuals immunized with the RT mutant and all the 18 controls had high levels of recoverable HIV-1. This indicates that mutation of RT reduces the desired immunogenicity.
|
|
| 4. |
- Kazaks, A, et al.
(författare)
-
Stop codon insertion restores the particle formation ability of hepatitis B virus core-hantavirus nucleocapsid protein fusions
- 2002
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 45:4-6, s. 340-349
-
Tidskriftsartikel (refereegranskat)abstract
- In recent years, epitopes of various origin have been inserted into the core protein of hepatitis B virus (HBc), allowing the formation of chimeric HBc particles. Although the C-terminus of a C-terminally truncated HBc (HBcΔ) tolerates the insertion of extended foreign sequences, the insertion capacity is still a limiting factor for the construction of multivalent vaccines. Previously, we described a new system to generate HBcΔ mosaic particles based on a read-through mechanism in an <i>Escherichia coli</i> suppressor strain [J Gen Virol 1997;78:2049–2053]. Those mosaic particles allowed the insertion of a 114-amino acid (aa)-long segment of a Puumala hantavirus (PUUV) nucleocapsid (N) protein. To study the value and the potential limitations of the mosaic approach in more detail, we investigated the assembly capacity of ‘non-mosaic’ HBcΔ fusion proteins and the corresponding mosaic constructs carrying 94, 213 and 433 aa of the hantaviral N protein. Whereas the fusion proteins carrying 94, 114, 213 or 433 aa were not assembled into HBcΔ particles, or only at a low yield, the insertion of a stop codon-bearing linker restored the ability to form particles with 94, 114 and 213 foreign aa. The mosaic particles formed exhibited PUUV-N protein antigenicity. Immunization of BALB/c mice with these mosaic particles carrying PUUV-N protein aa 1–114, aa 1–213 and aa 340–433, respectively, induced HBc-specific antibodies, whereas PUUV-N protein-specific antibodies were detected only in mice immunized with particles carrying N-terminal aa 1–114 or aa 1–213 of the N protein. Both the anti-HBc and anti-PUUV antibody responses were IgG1 dominated. In conclusion, stop codon suppression allows the formation of mosaic core particles carrying large-sized and ‘problematic’, e.g. hydrophobic, hantavirus sequences.
|
|
| 5. |
- Li, Quan-Gen, et al.
(författare)
-
Genetic relationship between thirteen genome types of adenovirus 11, 34, and 35 with different tropisms
- 1991
-
Ingår i: Intervirology. - : S. Karger. - 0300-5526 .- 1423-0100. ; 32:6, s. 338-350
-
Tidskriftsartikel (refereegranskat)abstract
- Eleven genome types of adenovirus serotype 11 (Ad11) were identified among 20 strains isolated from healthy pregnant women and patients with urinary tract infections, respiratory tract infections, or pharyngoconjunctival fever by use of 13 restriction endonucleases: BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, PstI, SalI, SmaI, XbaI, and XhoI. All genome types could be grouped into three genomic clusters according to their genetic homology expressed as pairwise comigrating restriction fragments. The genome types within a genomic cluster were very closely related. They shared on an average pairwise comigrating restriction fragments of 91.6-97.7%. The Ad11 strains of genomic clusters 1 and 3 were isolated from urine, whereas all the Ad11 strains isolated from the respiratory tract were identified as members of the genomic cluster 2. One genome type of Ad34 and one genome type of Ad35 were identified from a hemorrhagic cystitis patient and an organ transplant recipient, respectively. Both were closely related to Ad11. The genome type of Ad35 could be located in the Ad11 genomic cluster 1.
|
|
| 6. |
- Liu, Wen-Chun, et al.
(författare)
-
Genotyping of Hepatitis B Virus - Genotypes A to G by Multiplex Polymerase Chain Reaction
- 2008
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 51:4, s. 247-252
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Objectives:</i> Eight genotypes (A–H) of hepatitis B virus (HBV) are known with variations in nucleotide sequences greater than 8%. Several recent publications found that the clinical course and outcome of antiviral therapy depended on the genotype of the infecting HBV strain. Large epidemiological studies will require the availability of a system which is rapid, reliable and can be performed on a large number of samples. <i>Methods:</i> To establish a simple and accurate genotyping method, the study collected 369 HBV complete genomic sequences from the GenBank database. Type-specific primers were also designed that separated HBV genotypes A to G by multiplex polymerase chain reaction. <i>Results:</i> By comparison with the traditional restriction fragment length polymorphism method, over 93% of 441 samples were accurately genotyped by current assay, with a higher detection rate and sensitivity to detect mixed HBV infections. <i>Conclusions:</i> This methodology can be applied only to areas prevalent with HBV genotypes A to G. However, it provides an efficient alternative for clinical diagnosis and large-scale studies.
|
|
| 7. |
- Norder, Helene, et al.
(författare)
-
Hepatitis E Virus Genotype 3 Genomes from RNA-Positive but Serologically Negative Plasma Donors Have CUG as the Start Codon for ORF3
- 2018
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 61:2, s. 96-103
-
Tidskriftsartikel (refereegranskat)abstract
- Hepatitis E virus (HEV) is a pathogen that causes hepatitis worldwide. Molecular studies have identified HEV RNA in blood products although its significance is not understood. This study was undertaken to characterize HEV genomes in asymptomatic plasma donors from Sweden and Germany lacking anti-HEV. Complete open reading frames (ORFs) were obtained from HEV strains in 5 out of 18 plasma donors who tested positive for HEV RNA. All strains had CUG as the start codon of ORF3, while 147 GenBank strains all had AUG as the start codon (p < 0.0001). This substitution was found in both interrelated and unrelated strains belonging to different phylogenetic clades. The HEV strains from the seronegative plasma donors had no other substitution in common, which may be why the CUG substitution seems to ex- plain the seronegativity. (C) 2018 The Author(s) Published by S. Karger AG, Basel
|
|
| 8. |
- Oette, M, et al.
(författare)
-
Efficacy of antiretroviral therapy switch in HIV-infected patients: a 10-year analysis of the EuResist Cohort
- 2012
-
Ingår i: Intervirology. - : S. Karger AG. - 1423-0100 .- 0300-5526. ; 55:2, s. 160-166
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Introduction:</i> Highly active antiretroviral therapy (HAART) has been shown to be effective in many recent trials. However, there is limited data on time trends of HAART efficacy after treatment change. <i>Methods:</i> Data from different European cohorts were compiled within the EuResist Project. The efficacy of HAART defined by suppression of viral replication at 24 weeks after therapy switch was analyzed considering previous treatment modifications from 1999 to 2008. <i>Results:</i> Altogether, 12,323 treatment change episodes in 7,342 patients were included in the analysis. In 1999, HAART after treatment switch was effective in 38.0% of the patients who had previously undergone 1–5 therapies. This figure rose to 85.0% in 2008. In patients with more than 5 previous therapies, efficacy rose from 23.9 to 76.2% in the same time period. In patients with detectable viral load at therapy switch, the efficacy rose from 23.3 to 66.7% with 1–5 previous treatments and from 14.4 to 55.6% with more than 5 previous treatments. <i>Conclusion:</i> The results of this large cohort show that the outcome of HAART switch has improved considerably over the last years. This result was particularly observed in the context after viral rebound. Thus, changing HAART is no longer associated with a high risk of treatment failure.
|
|
| 9. |
- Ohara, N, et al.
(författare)
-
Sequence analysis and variation of EBNA-1 in Epstein-Barr virus-related herpesvirus of cynomolgus monkey
- 2000
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 43:2, s. 102-106
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Objectives:</i> The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is an important protein for immortalization and tumorigenesis of infected cells. EBNA-1 gene variants may play a role in tumorigenesis. We determined the nucleotide and amino acid (aa) sequences of EBNA-1 in EBV-related herpesviruses from cynomolgus monkeys (cynomolgus-EBV) which induced malignant lymphomas in its natural host and in rabbits, and compared them with sequences of EBV and other lymphocryptoviruses (LCVs). <i>Methods:</i> Polymerase chain reaction and direct sequencing methods were performed using extracted DNA from cynomolgus-EBV-infected cell lines. <i>Results:</i> The amino acid sequences of cynomolgus-EBV EBNA-1 from two cell lines (Si-IIA: 588 aa; Ts-B6: 619 aa) which are antigenically cross-reactive to human EBV EBNA-1 showed homology with human EBV (Si-IIA: 53%; Ts-B6: 58%) and other LCVs from baboons (54 and 52%) and rhesus monkeys (60 and 58%), especially in the C-terminal unique domain. Homology of the EBNA-1 sequence between Si-IIA and Ts-B6 was 92%. The sequence difference between EBV and the related LCVs was manifested mainly in the length of the internal repeat 3-corresponding region, which contains serine in the glycine/alanine repeat region of nonhuman LCVs. <i>Conclusion:</i> Sequence variation of cynomolgus-EBV EBNA-1 from different cell lines was observed. However, their sequences show a relatively high homology with human EBV and share the common features of EBNA-1 of EBV and other LCVs.
|
|
| 10. |
- Sallberg, M, et al.
(författare)
-
A malaria vaccine candidate based on a hepatitis B virus core platform
- 2002
-
Ingår i: Intervirology. - : S. Karger AG. - 0300-5526 .- 1423-0100. ; 45:4-6, s. 350-361
-
Tidskriftsartikel (refereegranskat)abstract
- <i>Objective:</i> The recent success of a <i>Plasmodium falciparum</i> malaria vaccine consisting of circumsporozoite (CS) protein (CSP) T and B cell epitopes has rekindled interest in the development of a pre-erythrocytic vaccine. Our goal was to design an efficient delivery system for known neutralizing epitopes. <i>Methods:</i> Well-characterized CSP-specific neutralizing B cell epitopes and a ‘universal’ T cell epitope were combined with a particulate carrier platform, the hepatitis B core antigen (HBcAg), to produce a novel pre-erythrocytic vaccine candidate. <i>Results:</i> The vaccine candidate V12.PF3.1 is a potent immunogen in mice, eliciting unprecedented levels (greater than 10<sup>6</sup> titers) of sporozoite-binding antibodies after only two doses. The antisporozoite antibodies are long-lasting and represent all IgG isotypes, and antibody production is not genetically restricted. CSP-specific CD4+ T cells are also primed by V12.PF3.1 immunization in a majority of murine strains. Furthermore, the hybrid HBcAg-CS particles can be produced inexpensively in bacterial expression systems. <i>Conclusion:</i> These characteristics suggest that V12.PF3.1 represents an efficient and economical <i>P. falciparum</i> vaccine candidate for use separately or in combination with other formulations.
|
|
