المؤلفون: Yasuo Suzuki, Chao-Tan Guo, Hideo Goto, Tadanobu Takahashi, Takashi Suzuki, Daisei Miyamoto, Yoshihiro Kawaoka, Kazuya I.P.J. Hidari

المصدر: Journal of Virology. 79:11705-11715

مصطلحات موضوعية: Male, viruses, Immunology, Orthomyxoviridae, Neuraminidase, Hemagglutinin (influenza), Biology, Transfection, Virus Replication, medicine.disease_cause, Sialidase, Guanidines, Microbiology, Cell Line, Mice, chemistry.chemical_compound, Dogs, Virology, Enzyme Stability, Influenza, Human, Influenza A virus, medicine, Animals, Humans, Zanamivir, Enzyme Inhibitors, Late endosome, Pyrans, biochemical phenomena, metabolism, and nutrition, Hydrogen-Ion Concentration, biology.organism_classification, Endocytosis, Virus-Cell Interactions, Sialic acid, Mice, Inbred C57BL, Viral replication, chemistry, Insect Science, Sialic Acids, biology.protein

الوصف: N2 neuraminidase (NA) genes of the 1957 and 1968 pandemic influenza virus strains possessed avian-like low-pH stability of sialidase activity, unlike most epidemic strains. We generated four reverse-genetics viruses from a genetic background of A/WSN/33 (H1N1) that included parental N2 NAs of 1968 pandemic (H3N2) and epidemic (H2N2) strains or their counterpart N2 NAs in which the low-pH stability of the sialidase activity was changed by substitutions of one or two amino acid residues. We found that the transfectant viruses bearing low-pH-stable sialidase (WSN/Stable-NAs) showed 25- to 80-times-greater ability to replicate in Madin-Darby canine kidney (MDCK) cells than did the transfectant viruses bearing low-pH-unstable sialidase (WSN/Unstable-NAs). Enzymatic activities of WSN/Stable-NAs were detected in endosomes of MDCK cells after 90 min of virus internalization by in situ fluorescent detection with 5-bromo-4-chloro-indole-3-yl-α- N -acetylneuraminic acid and Fast Red Violet LB. Inhibition of sialidase activity of WSN/Stable-NAs on the endocytic pathway by pretreatment with 4-guanidino-2,4-dideoxy- N -acetylneuraminic acid (zanamivir) resulted in a significant decrease in progeny viruses. In contrast, the enzymatic activities of WSN/Unstable-NAs, the replication of which had no effect on pretreatment with zanamivir, were undetectable in cells under the same conditions. Hemadsorption assays of transfectant-virus-infected cells revealed that the low-pH stability of the sialidase had no effect on the process of removal of sialic acid from hemagglutinin in the Golgi regions. Moreover, high titers of viruses were recovered from the lungs of mice infected with WSN/Stable-NAs on day 3 after intranasal inoculation, but WSN/Unstable-NAs were cleared from the lungs of the mice. These results indicate that sialidase activity in late endosome/lysosome traffic enhances influenza A virus replication.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0cfbfd13e5cc1519f5c841d834a27d92Test
https://doi.org/10.1128/jvi.79.18.11705-11715.2005Test

المؤلفون: Chak Sangma, Prasert Auewarakul, Louisirirotchanakul S, Ornpreya Suptawiwat, Chakrarat Pittayawonganon, Phisanu Pooruk, Supamit Chunsutthiwat, Wipawee Jampangern, Yasuo Suzuki, Hiroaki Hiramatsu, Hatairat Lerdsamran, Alita Kongchanagul, Kumnuan Ungchusak, Pilaipan Puthavathana, Arunee Thitithanyanont, Chao-Tan Guo

المصدر: Journal of virology. 81(18)

مصطلحات موضوعية: Models, Molecular, Immunology, Orthomyxoviridae, Population, Hemagglutinin (influenza), Hemagglutinin Glycoproteins, Influenza Virus, medicine.disease_cause, Microbiology, H5N1 genetic structure, Virus, chemistry.chemical_compound, Virology, Influenza, Human, medicine, Humans, education, Mutation, education.field_of_study, Binding Sites, biology, Influenza A Virus, H5N1 Subtype, biology.organism_classification, Influenza A virus subtype H5N1, N-Acetylneuraminic Acid, Protein Structure, Tertiary, Virus-Cell Interactions, chemistry, Insect Science, biology.protein, Receptors, Virus, N-Acetylneuraminic acid, Protein Binding

الوصف: Avian influenza viruses preferentially recognize sialosugar chains terminating in sialic acid-α2,3-galactose (SAα2,3Gal), whereas human influenza viruses preferentially recognize SAα2,6Gal. A conversion to SAα2,6Gal specificity is believed to be one of the changes required for the introduction of new hemagglutinin (HA) subtypes to the human population, which can lead to pandemics. Avian influenza H5N1 virus is a major threat for the emergence of a pandemic virus. As of 12 June 2007, the virus has been reported in 45 countries, and 312 human cases with 190 deaths have been confirmed. We describe here substitutions at position 129 and 134 identified in a virus isolated from a fatal human case that could change the receptor-binding preference of HA of H5N1 virus from SAα2,3Gal to both SAα2,3Gal and SAα2,6Gal. Molecular modeling demonstrated that the mutation may stabilize SAα2,6Gal in its optimal cis conformation in the binding pocket. The mutation was found in approximately half of the viral sequences directly amplified from a respiratory specimen of the patient. Our data confirm the presence of H5N1 virus with the ability to bind to a human-type receptor in this patient and suggest the selection and expansion of the mutant with human-type receptor specificity in the human host environment.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::97a60db8b01557bac3d6150088b7c2ccTest
https://pubmed.ncbi.nlm.nih.gov/17626098Test

المؤلفون: Suzuki, Takashi^1,2 Suzukit@u-shizuoka-ken.ac.jp, Takahashi, Tadanobu^1,2, Chao-Tan Guo^1,2,3, Jwa Hidari, Kazuya I.-P.^1,2, Miyamoto, Daisei^1,2, Goto, Hideo^2,4, Kawaoka, Yoshihiro^2,4,5,6, Suzuki, Yasuo^1,2

المصدر: Journal of Virology. Sep2005, Vol. 79 Issue 18, p11705-11715. 11p. 1 Color Photograph, 1 Black and White Photograph, 1 Chart, 6 Graphs.

مصطلحات موضوعية: *NEURAMINIDASE, *GENES, *INFLUENZA viruses, *EPIDEMICS, *VIRUSES, *INFLUENZA, *VIROLOGY

مستخلص: N2 neuraminidase (NA) genes of the 1957 and 1968 pandemic influenza virus strains possessed avian-like low-pH stability of sialidase activity, unlike most epidemic strains. We generated four reverse-genetics viruses from a genetic background of A/WSN/33 (H1N1) that included parental N2 NAs of 1968 pandemic (H3N2) and epidemic (H2N2) strains or their counterpart N2 NAs in which the low-pH stability of the sialidase activity was changed by substitutions of one or two amino acid residues. We found that the transfectant viruses bearing low-pH-stable sialidase (WSN/Stable-NAs) showed 25- to 80-times-greatec ability to replicate in Madin-Darby canine kidney (MDCK) cells than did the transfectant viruses bearing low-pH-unstable sialidase (WSN/Unstable-NAs). Enzymatic activities of WSN/Stable-NAs were detected in endosomes of MDCK cells after 90 rain of virus internalization by in situ fluorescent detection with 5-bromo-4-chloro-indole-3-yl-α-N-acetylneuraminic acid and Fast Red Violet LB. Inhibition of sialidase activity of WSN/Stable-NAs on the endocytic pathway by pretreatment with 4-guanidino-2,4-dideoxy-N-acetylneuraminic acid (zanamivir) resulted in a significant decrease in progeny viruses. In contrast, the enzymatic activities of WSN/Unstable-NAs, the replication of which had no effect on pretreatment with zanamivir, were undetectable in cells under the same conditions. Hemadsorption assays of transfectant-virus-infected cells revealed that the low-pH stability of the sialidase had no effect on the process of removal of sialic acid from hemagglutinin in the Golgi regions. Moreover, high titers of viruses were recovered from the lungs of mice infected with WSN/Stable-NAs on day 3 after intranasal inoculation, but WSN/Unstable-NAs were cleared from the lungs of the mice. These results indicate that sialidase activity in late endosome/lysosome traffic enhances influenza A virus replication. [ABSTRACT FROM AUTHOR]

المؤلفون: Takahashi, Tadanobu^1,2, Murakami, Kouki^1,2, Nagakura, Momoe^1,2, Kishita, Hideyuki^1,2, Watanabe, Shinya^1,2, Honke, Koichi^2,3, Ogura, Kiyoshi⁴, Tai, Tadashi⁴, Kawasaki, Kazunori⁵, Miyamoto, Daisei^1,2, Hidari, Kazuya I. P. J.^1,2, Chao-Tan Guo^2,6, Suzuki, Yasuo^2,6, Suzuki, Takashi^1,2 Suzukit@u-shizuoka-ken.ac.jp

المصدر: Journal of Virology. Jun2008, Vol. 82 Issue 12, p5940-5950. 11p.

مصطلحات موضوعية: *INFLUENZA A virus

مستخلص: An abstract of the article "Sulfatide Is Required for Efficient Replication of Influenza A Virus," by Tadanobu Takahashi, Kouki Murakami, Momoe Nagakura, Hideyuki Kishita, Shinya Watanabe, Koichi Honke, Kiyoshi Ogura, Tadashi Tai, Kazunori Kawasaki, Daisei Miyamoto, and colleagues is presented.

المؤلفون: Auewarakul, Prasert¹ sipaw@mahido.ac.th, Suptawiwat, Ornpreya¹, Kongchanagul, Alita¹, Sangma, Chak², Suzuki, Yasuo³, Ungchusak, Kumnuan⁴, Louisirirotchanakul, Suda¹, Lerdsamran, Hatairat¹, Pooruk, Phisanu¹, Thitithanyanont, Arunee⁵, Pittayawonganon, Chakrarat⁴, Chao-Tan Guo³, Hiramatsu, Hiroaki³, Jampangern, Wipawee⁵, Chunsutthiwat, Supamit⁶, Puthavathana, Pilaipan¹

المصدر: Journal of Virology. Sep2007, Vol. 81 Issue 18, p38-38. 1p.

مصطلحات موضوعية: *INFLUENZA viruses, *AVIAN influenza, *IMMUNOSPECIFICITY, *HEMAGGLUTININ, *GENETIC mutation

مستخلص: Avian influenza viruses preferentially recognize sialosugar chains terminating in sialic acid- α 2,3-galactose (SA α2,3Gal), whereas human influenza viruses preferentially recognize SA α 2,6Gal. A conversion to SA α 2,6Gal specificity is believed to be one of the changes required for the introduction of new hemagglutinin (HA) subtypes to the human population, which can lead to pandemics. Avian influenza H5N1 virus is a major threat for the emergence of a pandemic virus. As of 12 June 2007, the virus has been reported in 45 countries, and 312 human cases with 190 deaths have been confirmed. We describe here substitutions at position 129 and 134 identified in a virus isolated from a fatal human case that could change the receptor-binding preference of HA of H5N1 virus from SA α 2,3Gal to both SA α2,3Gal and SA α 2,6Gal. Molecular modeling demonstrated that the mutation may stabilize SA α 2,6Gal in its optimal cis conformation in the binding pocket. The mutation was found in approximately half of the viral sequences directly amplified from a respiratory specimen of the patient. Our data confirm the presence of H5N1 virus with the ability to bind to a human-type receptor in this patient and suggest the selection and expansion of the mutant with human-type receptor specificity in the human host environment. [ABSTRACT FROM AUTHOR]