Kobayashi Kenichiro, Katakura Yuki, Ito Yui, Kato Masaki, Goto Yoshiaki, Nakajima Hiromi
Nagano Prefecture Saku Livestock Hygiene Service Center, Saku, Japan.
Nagano Prefecture Matsumoto Livestock Hygiene Service Center, Matsumoto, Japan.
Vet Rec. 2024 Dec 14;195(12):e4909. doi: 10.1002/vetr.4909. Epub 2024 Dec 11.
Bovine leukaemia virus (BLV)-infected Holstein cattle carrying certain bovine leukocyte antigen (BoLA)-DRB3 alleles were previously shown to be resistant to BLV provirus multiplication, while those carrying other alleles were susceptible. This study aimed to determine whether the BoLA-DRB3 alleles carried by BLV-infected cattle could predict proviral load (PVL) and peripheral blood lymphocyte (PBL) count distribution (PVL/PBL distribution).
Blood samples from Holstein cattle on four dairy farms were tested for the presence of BLV antibodies using a commercial ELISA. The PVL and PBL levels of the BLV-infected cattle were also measured, and genotyping was performed to identify the BoLA-DRB3 alleles they carried, impact of the various BoLA-DRB3 alleles on the PVL/PBL distribution was then investigated.
Of the 316 cattle tested, 114 were positive for BLV. BLV-infected cattle carrying BoLA-DRB3 alleles DRB3009:02, DRB3002:01 and DRB3014:01:01 were classified as resistant (n = 43), those carrying DRB3012:01 and DRB3015:01 alleles were classified as susceptible (n = 42) and the remaining cattle were classified as nonsusceptible/nonresistant (n = 29). Multiple regression analysis revealed that PVL was positively correlated (p = 2.1 × 10) with PBL count and age was negatively correlated (p = 1.9 × 10) with PBL count. Cattle with DRB3014:01:01 tended to have a lower PBL count (p = 0.031).
The effects of the BoLA-DRB3 alleles DRB3002:01, DRB3009:02, DRB3012:01 and DRB3015:01 on PVL/PBL distribution were unclear due to the small numbers of BLV-infected animals carrying these alleles.
The BLV transmission risk in cattle can be estimated by examining their BoLA-DRB3 alleles.
先前研究表明，感染牛白血病病毒（BLV）的荷斯坦奶牛若携带某些牛白细胞抗原（BoLA）-DRB3等位基因，则对BLV前病毒增殖具有抗性，而携带其他等位基因的奶牛则易感。本研究旨在确定感染BLV的奶牛所携带的BoLA-DRB3等位基因是否能够预测前病毒载量（PVL）和外周血淋巴细胞（PBL）计数分布（PVL/PBL分布）。
使用商用ELISA检测四个奶牛场荷斯坦奶牛的血样中是否存在BLV抗体。还测量了感染BLV奶牛的PVL和PBL水平，并进行基因分型以鉴定它们所携带的BoLA-DRB3等位基因，随后研究了各种BoLA-DRB3等位基因对PVL/PBL分布的影响。
在检测的316头奶牛中，114头BLV呈阳性。携带BoLA-DRB3等位基因DRB3009:02、DRB3002:01和DRB3014:01:01的感染BLV奶牛被归类为抗性奶牛（n = 43），携带DRB3012:01和DRB3015:01等位基因的奶牛被归类为易感奶牛（n = 42），其余奶牛被归类为非易感/非抗性奶牛（n = 29）。多元回归分析显示，PVL与PBL计数呈正相关（p = 2.1×10），年龄与PBL计数呈负相关（p = 1.9×10）。携带DRB3014:01:01的奶牛PBL计数往往较低（p = 0.031）。
由于携带这些等位基因的感染BLV动物数量较少，BoLA-DRB3等位基因DRB3002:01、DRB3009:02、DRB3012:01和DRB3015:01对PVL/PBL分布的影响尚不清楚。
通过检测奶牛的BoLA-DRB3等位基因，可以估计牛群中BLV的传播风险。
