Elucidating the characteristics of Mx1 and resistance to influenza A virus subtype H1N1 in the newly developed KWM/Hym mice

• Published in: Laboratory animal research Vol. 38; no. 1; pp. 1 - 7
• Main Authors: Nam, Hajin, Kim, Boyoung, Gautam, Avishekh, Kim, Yoo Yeon, Park, Eun Sun, Lee, Jong Sun, Kwon, Hyung-Joo, Seong, Je Kyung, Suh, Jun Gyo
• Format: Journal Article
• Language: English
• Published: London BioMed Central 08.09.2022; BMC; 한국실험동물학회
• Subjects: Alveolitis; Amino acids; Biomedical and Life Sciences; Disease resistance; Epithelium; Gene manipulation; Genetic diversity; Inbreeding; Infections; Influenza A; Influenza A (H1N1) virus; Interferon; KWM/Hym mice; Life Sciences; Lungs; Mitochondrial DNA; Mutation; Mx1 gene; Proteins; Swine flu; Vertebrates; Viruses; 수의학; KWM/Hym mice; gene; Alveolitis; Influenza A (H1N1) virus
• ISSN: 2233-7660; 1738-6055; 2233-7660
• DOI: 10.1186/s42826-022-00138-z

Background Inbred mice have several advantages, including genetic similarity to humans, a well-established gene manipulation system, and strong tolerance to inbreeding. However, inbred mice derived from a limited genetic pool have a small genetic diversity. Thus, the development of new inbred strains from wild mice is needed to overcome this limitation. Hence, in this study, we used a new strain of inbred mice called KWM/Hym. We sequenced the Mx1 gene to elucidate the genetic diversities of KWM/Hym mice and observed the biological alterations of the Mx1 protein upon influenza A infection. Results The Mx1 gene in KWM/Hym mice had 2, 4, and 38 nucleotide substitutions compared to those in the Mx1 gene in A2G, CAST/EiJ, and Mus spretus mice, respectively. Moreover, the Mx1 protein in KWM/Hym mice had 2 and 25 amino acid substitutions compared to those in the Mx1 protein in CAST/EiJ and M. spretus mice, respectively. To elucidate the function of the Mx1 protein, we inoculated the influenza A virus (A/WSN/1933) in KWM/Hym mice. Nine days after infection, all infected KWM/Hym mice survived without any weight loss. Four days after infection, the lungs of the infected KWM/Hym mice showed mild alveolitis and loss of bronchiolar epithelium; however, the pulmonary viral titers of the infected KWM/Hym mice were significantly lower than that in the infected BALB/c mice (2.17 × plaque-forming units mL −1 ). Conclusions Our results demonstrate that the KWM/Hym mice are resistant to influenza A virus infection. Further, these mice can be used as a model organism to understand the mechanism of influenza A virus susceptibility.