Rika Tsutsui1,2, Hiroyuki Tsukagoshi3, Koo Nagasawa4, Masaki Takahashi5, Yuki Matsushima6, Akihide Ryo7, Makoto Kuroda8, Hideki Takami1, Hirokazu Kimura4,7. 1. Department of Pathologic Analysis, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1, Hon-cho, Hirosaki-shi, Aomori 036-8564, Japan. 2. Aomori Prefecture Public Health and Environment Center, 1-1-1, Higashitsukurimichi, Aomori-shi, Aomori 030-8566, Japan. 3. Gunma Prefectural Institute of Public Health and Environmental Sciences, 378 Kamioki-machi, Maebashi-shi, Gunma 371-0052, Japan. 4. Infectious Disease Surveillance Center, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama-shi, Tokyo 208-0011, Japan. 5. Research Institute for Environmental Sciences and Public Health of Iwate Prefecture, 1-11-16, Kitaiioka, Morioka-shi, Iwate 020-0857, Japan. 6. Division of Virology, Kawasaki City Institute for Public Health, 3-25-13, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-0821, Japan. 7. Department of Molecular Biodefence Research, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa 236-0004, Japan. 8. Pathogen Genomics Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
Abstract
PURPOSE: To genetically explore the fusion protein gene (F) in human parainfluenza virus type 1 (HPIV1) and type 3 (HPIV3) strains, we analysed them in patients with acute respiratory infections in Eastern Japan from 2011 to 2015. METHODOLOGY: We constructed phylogenetic trees based on the HPIV and HPIV3 F gene using the maximum likelihood method and conducted P-distance and selective pressure analyses. We also predicted the linear epitopes of the protein in the prototype strains. Furthermore, we mapped the amino acid substitutions of the proteins. RESULTS: Nineteen strains of HPIV1 and 53 strains of HPIV3 were detected among the clinical acute respiratory infection cases. The phylogenetic trees indicated that the HPIV1 and HPIV3 strains were classified into clusters II and III and cluster C, respectively. The P-distance values of the HPIV1 and HPIV3 F genes were <0.03. Two positive selection sites were inferred in the HPIV1 (aa 8 and aa 10), and one positive selection site was inferred in the HPIV3 (aa 108), but over 10 negative selection sites were inferred. Four epitopes were predicted for the HPIV1 prototype strains, while five epitopes were predicted for the HPIV3 prototype strain. A positive selection site (aa 108) or the HPIV3 F protein was involved in the predicted epitope. Additionally, we found that an amino acid substitution (R73K) in the LC76627 HPIV3 strain presumably may affect the resistance to neutralization by antibodies. CONCLUSION: The F gene of HPIV1 and HPIV3 was relatively well conserved in the eastern part of Japan during the investigation period.
PURPOSE: To genetically explore the fusion protein gene (F) in human parainfluenza virus type 1 (HPIV1) and type 3 (HPIV3) strains, we analysed them in patients with acute respiratory infections in Eastern Japan from 2011 to 2015. METHODOLOGY: We constructed phylogenetic trees based on the HPIV and HPIV3 F gene using the maximum likelihood method and conducted P-distance and selective pressure analyses. We also predicted the linear epitopes of the protein in the prototype strains. Furthermore, we mapped the amino acid substitutions of the proteins. RESULTS: Nineteen strains of HPIV1 and 53 strains of HPIV3 were detected among the clinical acute respiratory infection cases. The phylogenetic trees indicated that the HPIV1 and HPIV3 strains were classified into clusters II and III and cluster C, respectively. The P-distance values of the HPIV1 and HPIV3 F genes were <0.03. Two positive selection sites were inferred in the HPIV1 (aa 8 and aa 10), and one positive selection site was inferred in the HPIV3 (aa 108), but over 10 negative selection sites were inferred. Four epitopes were predicted for the HPIV1 prototype strains, while five epitopes were predicted for the HPIV3 prototype strain. A positive selection site (aa 108) or the HPIV3 F protein was involved in the predicted epitope. Additionally, we found that an amino acid substitution (R73K) in the LC76627 HPIV3 strain presumably may affect the resistance to neutralization by antibodies. CONCLUSION: The F gene of HPIV1 and HPIV3 was relatively well conserved in the eastern part of Japan during the investigation period.