<i>BoLA-DRB3</i> Polymorphism Controls Proviral Load and Infectivity of Bovine Leukemia Virus (BLV) in Milk
Ayumi Nakatsuchi,
Sonoko Watanuki,
Liushiqi Borjigin,
Hirotaka Sato,
Lanlan Bai,
Ryosuke Matsuura,
Maho Kuroda,
Hironobu Murakami,
Reiichiro Sato,
Sakurako Asaji,
Asako Ando,
Yasunobu Matsumoto,
Shin-Nosuke Takeshima,
Yoko Aida
Affiliations
Ayumi Nakatsuchi
Institute of Animal Health, JA Zen-Noh (National Federation of Agricultural Cooperative Associations), 7 Ohja-machi Sakura-shi, Chiba 285-0043, Japan
Sonoko Watanuki
Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Liushiqi Borjigin
Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Hirotaka Sato
Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Lanlan Bai
Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Ryosuke Matsuura
Laboratory of Global Infectious Diseases Control Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Maho Kuroda
Institute of Animal Health, JA Zen-Noh (National Federation of Agricultural Cooperative Associations), 7 Ohja-machi Sakura-shi, Chiba 285-0043, Japan
Hironobu Murakami
Laboratory of Animal Health II, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Kanagawa, Sagamihara 252-5201, Japan
Reiichiro Sato
Laboratory of Farm Animal Internal Medicine, Department of Veterinary Sciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
Sakurako Asaji
GenoDive Pharma Inc., 4-14-1 Naka-cho, Kanagawa, Atsugi 243-0018, Japan
Asako Ando
GenoDive Pharma Inc., 4-14-1 Naka-cho, Kanagawa, Atsugi 243-0018, Japan
Yasunobu Matsumoto
Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Shin-Nosuke Takeshima
Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Yoko Aida
Laboratory of Global Animal Resource Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Bovine leukemia virus (BLV), which causes enzootic bovine leukosis, is transmitted to calves through the milk of BLV-infected dams. Bovine leukocyte antigen (BoLA)-DRB3 is a polymorphic gene associated with BLV infectivity and proviral load (PVL). However, the effect of BoLA-DRB3 polymorphism on the infectivity and PVL of milk from BLV-infected dams remains unknown. This study examined milk from 259 BLV-infected dams, including susceptible dams carrying at least one BoLA-DRB3*012:01 or *015:01 allele with high PVL, resistant dams carrying at least one BoLA-DRB3*002:01, *009:02, or *014:01:01 allele with low PVL, and neutral dams carrying other alleles. The detection rate of BLV provirus and PVL were significantly higher in milk from susceptible dams than in that from resistant dams. This result was confirmed in a three-year follow-up study in which milk from susceptible dams showed a higher BLV provirus detection rate over a longer period than that from resistant dams. The visualization of infectivity of milk cells using a luminescence syncytium induction assay showed that the infectious risk of milk from BLV-infected dams was markedly high for susceptible dams compared to resistant ones. This is the first report confirming that BoLA-DRB3 polymorphism affects the PVL and infectivity of milk from BLV-infected dams.
