| 1. |
- Artursson, Elisabet, et al.
(författare)
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Catalytic-site conformational equilibrium in nerve-agent adducts of acetylcholinesterase : Possible implications for the HI-6 antidote substrate specificity
- 2013
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Ingår i: Biochemical Pharmacology. - : Elsevier. - 0006-2952 .- 1356-1839. ; 85:9, s. 1389-1397
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Tidskriftsartikel (refereegranskat)abstract
- Nerve agents such as tabun, cyclosarin and Russian VX inhibit the essential enzyme acetylcholinesterase (AChE) by organophosphorylating the catalytic serine residue. Nucleophiles, such as oximes, are used as antidotes as they can reactivate and restore the function of the inhibited enzyme. The oxime HI-6 shows a notably low activity on tabun adducts but can effectively reactivate adducts of cyclosarin and Russian VX. To examine the structural basis for the pronounced substrate specificity of HI-6, we determined the binary crystal structures of Mus musculus AChE (mAChE) conjugated by cyclosarin and Russian VX and found a conformational mobility of the side chains of Phe338 and His447. The interaction between HI-6 and tabun-adducts of AChE were subsequently investigated using a combination of time resolved fluorescence spectroscopy and X-ray crystallography. Our findings show that HI-6 binds to tabun inhibited Homo sapiens AChE (hAChE) with an IC50 value of 300 μM and suggest that the reactive nucleophilic moiety of HI-6 is excluded from the phosphorus atom of tabun. We propose that a conformational mobility of the side-chains of Phe338 and His447 is a common feature in nerve-agent adducts of AChE. We also suggest that the conformational mobility allow HI-6 to reactivate conjugates of cyclosarin and Russian VX while a reduced mobility in tabun conjugated AChE results in steric hindrance that prevents efficient reactivation.
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| 2. |
- Bzhalava, Davit, et al.
(författare)
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Deep sequencing extends the diversity of human papillomaviruses in human skin.
- 2014
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4:Jul 24
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Tidskriftsartikel (refereegranskat)abstract
- Most viruses in human skin are known to be human papillomaviruses (HPVs). Previous sequencing of skin samples has identified 273 different cutaneous HPV types, including 47 previously unknown types. In the present study, we wished to extend prior studies using deeper sequencing. This deeper sequencing without prior PCR of a pool of 142 whole genome amplified skin lesions identified 23 known HPV types, 3 novel putative HPV types and 4 non-HPV viruses. The complete sequence was obtained for one of the known putative types and almost the complete sequence was obtained for one of the novel putative types. In addition, sequencing of amplimers from HPV consensus PCR of 326 skin lesions detected 385 different HPV types, including 226 previously unknown putative types. In conclusion, metagenomic deep sequencing of human skin samples identified no less than 396 different HPV types in human skin, out of which 229 putative HPV types were previously unknown.
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| 3. |
- Bzhalava, Davit, et al.
(författare)
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Unbiased Approach for Virus Detection in Skin Lesions
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- To assess presence of virus DNA in skin lesions, swab samples from 82 squamous cell carcinomas of the skin (SCCs), 60 actinic keratoses (AKs), paraffin-embedded biopsies from 28 SCCs and 72 kerathoacanthomas (KAs) and fresh-frozen biopsies from 92 KAs, 85 SCCs and 92 AKs were analyzed by high throughput sequencing (HTS) using 454 or Ion Torrent technology. We found total of 4,284 viral reads, out of which 4,168 were Human Papillomavirus (HPV)-related, belonging to 15 known (HPV8, HPV12, HPV20, HPV36, HPV38, HPV45, HPV57, HPV59, HPV104, HPV105, HPV107, HPV109, HPV124, HPV138, HPV147), four previously described putative (HPV 915 F 06 007 FD1, FA73, FA101, SE42) and two putatively new HPV types (SE46, SE47). SE42 was cloned, sequenced, designated as HPV155 and found to have 76% similarity to the most closely related known HPV type. In conclusion, an unbiased approach for viral DNA detection in skin tumors has found that, although some new putative HPVs were found, known HPV types constituted most of the viral DNA.
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| 4. |
- Ekström, Johanna, et al.
(författare)
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Diversity of human papillomaviruses in skin lesions
- 2013
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Ingår i: Virology. - : Elsevier BV. - 0042-6822 .- 1096-0341. ; 447:1-2, s. 300-311
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Tidskriftsartikel (refereegranskat)abstract
- Pools of frozen biopsies from patients with squamous cell carcinoma (SCC) (n=29) actinic keratosis (AK) (n=31), keratoacanthoma (n=91) and swab samples from 84 SCCs and 91 AKs were analysed with an extended HPV general primer PCR and high-throughput sequencing of amplimers. We found 273 different HPV isolates (87 known HPV types, 139 previously known HPV sequences (putative types) and 47 sequences from novel putative HPV types). Among the new sequences, five clustered in genus Betapapillomavirus and 42 in genus Gammapapillomavirus. Resequencing of the three pools between 21 to 70 times resulted in the detection of 283 different known or putative HPV types, with 156 different sequences found in only one of the pools. Type-specific PCRs for 37 putative types from an additional 296 patients found only two of these putative types. In conclusion, skin lesions contain a large diversity of HPV types, but most appeared to be rare infections. (C) 2013 Elsevier Inc. All rights reserved.
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| 5. |
- Ekström, Johanna, et al.
(författare)
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High throughput sequencing reveals diversity of human papillomaviruses in cutaneous lesions.
- 2011
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 129, s. 2643-2650
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Tidskriftsartikel (refereegranskat)abstract
- There are at least 120 completely characterized human papillomavirus (HPV) types and putative new types are continuously found. Both squamous cell carcinoma of the skin (SCC) and other skin lesions commonly contain multiple cutaneous HPV types. The objective of this study was to achieve an improved resolution of the diversity of HPV types in lesions such as SCCs, actinic keratoses (AKs) and keratoacanthomas (KAs). Fresh frozen biopsies from 37 SCC lesions, 36 AK lesions and 92 KA lesions and swab samples from the top of the lesion from 86 SCCs and 92 AKs were amplified using the general HPV primers FAP and mixed to three pools followed by high throughput sequencing. We obtained 2196 reads with homology to HPV. In the pool of SCC/AK biopsies 48 different HPV types were found. Eighty-three types were found in the pool of SCC/AK swab samples and 64 types in the KA biopsies, respectively. For 9 novel putative HPV types most of the amplimer sequence was obtained, whereas for an additional 35 novel putative HPV types only partial amplimer sequences were obtained. Most of the novel putative types belonged to the genus Gamma. In conclusion, high throughput sequencing was an effective means to identify both known and previously unknown HPV types in putatively HPV-associated lesions and has revealed an extended diversity of HPV types.
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| 6. |
- Ekström, Jens-Ola, et al.
(författare)
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Drosophila Nora virus capsid proteins differ from those of other picorna-like viruses
- 2011
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Ingår i: Virus Research. - Amsterdam : Elsevier. - 0168-1702 .- 1872-7492. ; 160:1-2, s. 51-58
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Tidskriftsartikel (refereegranskat)abstract
- The recently discovered Nora virus from Drosophila melanogaster is a single-stranded RNA virus. Its published genomic sequence encodes a typical picorna-like cassette of replicative enzymes, but no capsid proteins similar to those in other picorna-like viruses. We have now done additional sequencing at the termini of the viral genome, extending it by 455 nucleotides at the 5' end, but no more coding sequence was found. The completeness of the final 12,333-nucleotide sequence was verified by the production of infectious virus from the cloned genome. To identify the capsid proteins, we purified Nora virus particles and analyzed their proteins by mass spectrometry. Our results show that the capsid is built from three major proteins, VP4A, B and C, encoded in the fourth open reading frame of the viral genome. The viral particles also contain traces of a protein from the third open reading frame, VP3. VP4A and B are not closely related to other picorna-like virus capsid proteins in sequence, but may form similar jelly roll folds. VP4C differs from the others and is predicted to have an essentially α-helical conformation. In a related virus, identified from EST database sequences from Nasonia parasitoid wasps, VP4C is encoded in a separate open reading frame, separated from VP4A and B by a frame-shift. This opens a possibility that VP4C is produced in non-equimolar quantities. Altogether, our results suggest that the Nora virus capsid has a different protein organization compared to the order Picornavirales.
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| 7. |
- Ekström, Johanna, et al.
(författare)
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Three novel papillomaviruses (HPV109, HPV112 and HPV114) and their presence in cutaneous and mucosal samples.
- 2010
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Ingår i: Virology. - : Elsevier BV. - 1096-0341 .- 0042-6822. ; 397, s. 331-336
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Tidskriftsartikel (refereegranskat)abstract
- To expand our knowledge of the genomic diversity of human papillomaviruses (HPVs), we searched for new HPVs in squamous cell carcinomas of the skin (SCC) and seemingly HPV-negative, otherwise typically HPV-associated lesions. We describe the characterization of three novel HPV types. HPV109 was isolated from an SCC, HPV112 from a condyloma and HPV114 from a low-grade cervical lesion. Pairwise alignment of the L1 sequences classified HPV114 to genus alpha species 3, whereas HPV112 defined a new species in the genus gamma. HPV109 had uncertain classification because of a low and about equal similarity in the L1 gene (between 60% and 65%) to different genera. Type-specific real-time PCRs of cervical samples, a majority from women with low grade atypical cytology, (n=2856) and various cutaneous samples (n=538), found HPV114 in 1.7% (48/2856) of the genital samples, whereas both HPV109 and 112 were rare viruses found at high viral loads only in their index samples.
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| 8. |
- Gustafsson, Ola, et al.
(författare)
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A fibrous membrane suspends the multifocal lens in the eyes of lampreys and African lungfishes.
- 2010
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Ingår i: Journal of Morphology. - : Wiley. - 1097-4687 .- 0362-2525. ; 271:8, s. 980-989
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Tidskriftsartikel (refereegranskat)abstract
- The sharpness and thus information content of the retinal image in the eye depends on the optical quality of the lens and its accurate positioning in the eye. Multifocal lenses create well-focused color images and are present in the eyes of all vertebrate groups studied to date (mammals, reptiles including birds, amphibians, and ray-finned fishes) and occur even in lampreys, i.e., the most basal vertebrates with well-developed eyes. Results from photoretinoscopy obtained in this study indicate that the Dipnoi (lungfishes), i.e., the closest piscine relatives to tetrapods, also possess multifocal lenses. Suspension of the lens is complex and sophisticated in teleosts (bony fishes) and tetrapods. We studied lens suspension using light and electron microscopy in one species of lamprey (Lampetra fluviatilis) and two species of African lungfish (Protopterus aethiopicus aethiopicus and Protopterus annectens annectens). A fibrous and highly transparent membrane suspends the lens in both of these phylogenetically widely separated vertebrate groups. The membrane attaches to the lens approximately along the lens equator, from where it extends to the ora retinalis. The material forming the membrane is similar in ultrastructure to microfibrils in the zonule fibers of tetrapods. The membrane, possibly in conjunction with the cornea, iris, and vitreous body, seems suitable for keeping the lens in the correct position for well-focused imaging. Suspension of the lens by a multitude of zonule fibers in tetrapods may have evolved from a suspensory membrane similar to that in extant African lungfishes, a structure that seems to have appeared first in the lamprey-like ancestors of allextant vertebrates.
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| 9. |
- Gustafsson, Ola, et al.
(författare)
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Sturgeons, sharks, and rays have multifocal crystalline lenses and similar lens suspension apparatuses.
- 2012
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Ingår i: Journal of Morphology. - : Wiley. - 1097-4687 .- 0362-2525. ; 273:7, s. 746-753
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Tidskriftsartikel (refereegranskat)abstract
- Crystalline lenses with multiple focal lengths in monochromatic light (multifocal lenses) are present in many vertebrate groups. These lenses compensate for chromatic aberration and create well-focused color images. Stabilization of the lens within the eye and the ability to adjust focus are further requirements for vision in high detail. We investigated the occurrence of multifocal lenses by photorefractometry and lens suspension structures by light and electron microscopy in sturgeons (Acipenseriformes, Chondrostei) as well as sharks and rays (Elasmobranchii, Chondrichthyes). Multifocal lenses were found in two more major vertebrate groups, the Chondrostei represented by Acipenseriformes and Chondrichthyes represented by Elasmobranchii. The lens suspension structures of sturgeons, sharks, and rays are more complex than described previously. The lens is suspended by many delicate suspensory fibers in association with a ventral papilla in all groups studied. The arrangements of the suspensory fibers are most similar between sturgeons and sharks. In rays, the lens is suspended by a smaller ventral papilla and the suspensory fibers are arranged more concentrically to the lens. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
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| 10. |
- Israelsson, Stina, et al.
(författare)
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Improved replication efficiency of echovirus 5 after transfection of colon cancer cells using an authentic 5' RNA genome end methodology
- 2014
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Ingår i: Investigational new drugs. - : Springer Science and Business Media LLC. - 0167-6997 .- 1573-0646. ; 32:6, s. 1063-1070
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Tidskriftsartikel (refereegranskat)abstract
- Oncolytic virotherapy is a promising novel form of cancer treatment, but the therapeutic efficiency needs improvement. A potential strategy to enhance the therapeutic effect of oncolytic viruses is to use infectious nucleic acid as therapeutic agent to initiate an oncolytic infection, without administrating infectious viral particles. Here we demonstrate improved viral replication activation efficiency when transfecting cells with 5’ end authentic in vitro transcribed enterovirus RNA as compared to genomic RNA with additional non-genomic 5’ nucleotides generated by conventional cloning methods. We used echovirus 5 (E5) as an oncolytoc model virus due to its ability to replicate in and completely destroy five out of six colon cancer cell lines and kill artificial colon cancer tumors (HT29 spheroids), as shown here. An E5 infectious cDNA clone including a hammerhead ribozyme sequence was used to generate in vitro transcripts with native 5’ genome ends. In HT29 cells, activation of virus replication is approximately 20-fold more efficient for virus genome transcripts with native 5’ genome ends compared to E5 transcripts generated from a standard cDNA clone. This replication advantage remains when viral progeny release starts by cellular lysis 22 h post transfection. Hence, a native 5’ genomic end improves infection activation efficacy of infectious nucleic acid, potentially enhancing its therapeutic effect when used for cancer treatment. The clone design with a hammerhead ribozyme is likely to be applicable to a variety of oncolytic positive sense RNA viruses for the purpose of improving the efficacy of oncolytic virotherapy.
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