Isolation and characterization of Iwanai Valley virus, a new tick-borne nairovirus from Ixodes ovatus ticks in Hokkaido, Japan

• Published in: Archives of virology Vol. 170; no. 1; p. 23
• Main Authors: Matsumura, Ryo, Kobayashi, Daisuke, Yamauchi, Takeo, Park, Eunsil, Nishino, Ayano, Maeda, Ken, Kasai, Shinji, Itoyama, Kyo, Isawa, Haruhiko
• Format: Journal Article
• Language: English
• Published: Austria Springer Nature B.V 01.01.2025
• Subjects: Adenocarcinoma; Amino Acid Sequence; amino acid sequences; amino acids; Animals; Arachnids; Cell Line; Cercopithecus aethiops; Chlorocebus aethiops; Cricetinae; Crimean hemorrhagic fever; Crimean-Congo hemorrhagic fever orthonairovirus; Dugbe orthonairovirus; genus; Geographical distribution; Hepatocellular carcinoma; hepatoma; Humans; Ixodes - virology; Ixodes ovatus; Ixodes scapularis; Japan; Kidneys; Liver cancer; Mesocricetus auratus; Nairobi sheep disease; Nairovirus - classification; Nairovirus - genetics; Nairovirus - isolation & purification; nucleoproteins; Nucleoproteins - genetics; Phylogeny; Public health; ticks; Vero Cells; Viruses; Japan; East Asia
• DOI: 10.1007/s00705-024-06195-0
• ISSN: 0304-8608; 1432-8798

Most members of the genus Orthonairovirus, represented by Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, are tick-borne, and some have become a public health concern in recent years. Here, we report the isolation and genetic and biological characterization of a new orthonairovirus, designated as "Iwanai Valley virus" (IWVV), from Ixodes ovatus ticks in Hokkaido, Japan. The amino acid sequence of the viral nucleoprotein (NP) was found to be 34-45% identical to those of known orthonairoviruses. Phylogenetic analysis based on amino acid sequences of the viral NP revealed that IWVV is closely related to human-pathogenic tick-borne orthonairoviruses, including Songling virus, Tacheng tick virus 1, and Yezo virus, which were recently discovered in East Asia. BHK-21 (Syrian hamster kidney), Vero (African green monkey kidney), SW-13 (human adrenal adenocarcinoma), HuH-7 (human hepatocellular carcinoma), and ISE6 (Ixodes scapularis tick embryo) cells were found to be susceptible to IWVV infection. Notably, several human-derived cell lines supported efficient replication of the virus. Our findings provide new insights into the diversity, evolutionary dynamics, and geographical distribution of orthonairoviruses in East Asia.