Programa de Pós-Graduação em Ciência Animal, Universidade Federal da Paraíba, Areia 58397-000, Brazil; Núcleo Aplicado à Produção e Sanidade da Glândula Mamária (NAPROSA), Departamento de Ciências Veterinárias, Centro de Ciências Agrárias, Universidade Federal da Paraíba, Areia 58397-000, Brazil.
Programa de Pós-Graduação em Ciência Animal, Universidade Federal da Paraíba, Areia 58397-000, Brazil; Núcleo Aplicado à Produção e Sanidade da Glândula Mamária (NAPROSA), Departamento de Ciências Veterinárias, Centro de Ciências Agrárias, Universidade Federal da Paraíba, Areia 58397-000, Brazil.
Vet Immunol Immunopathol. 2023 Sep;263:110636. doi: 10.1016/j.vetimm.2023.110636. Epub 2023 Aug 9.
Bovine leukemia virus (BLV) is caused by a deltaretrovirus and has been associated with immunosuppression as well as comorbidities such as bovine mastitis, the costliest disease in the dairy sector. However, no previous study has explored at the synergistic immunosuppressive effect of the peripartum period with an immunosuppressive viral disease such as BLV. Thus, our study explored the effect of BLV infection in the periparturient period on the expression of PD-1 and CTLA-4 in blood T lymphocytes, and the impact of BLV infection on the rate of new intramammary infections during the early lactation. Here, we found that BLV-infected dairy cows always had a statistically significant higher expression of CTLA-4 and PD-1 in blood T cells. Furthermore, our findings indicated that BLV infection prolongs immunosuppression in dairy cows during the periparturient period by sustaining higher expression of immunological checkpoints in T cells. In addition, BLV-infected dairy cows have a higher rate of new intramammary infections during early lactation. Thus, our study provides new insights of the immunosuppressive effect of BLV on the most critical period of the cows' life with marked detrimental effect on protective T-cell immunity and comorbidities, such as bovine mastitis.
牛白血病病毒（BLV）由一种δ逆转录病毒引起，与免疫抑制以及牛乳腺炎等合并症有关，而牛乳腺炎是奶牛业中最昂贵的疾病。然而，以前的研究并未探讨围产期与 BLV 等免疫抑制性病毒疾病的协同免疫抑制作用。因此，我们的研究探讨了围产期 BLV 感染对血液 T 淋巴细胞中 PD-1 和 CTLA-4 表达的影响，以及 BLV 感染对泌乳早期新发生乳腺炎的影响。在这里，我们发现 BLV 感染的奶牛血液 T 细胞中 CTLA-4 和 PD-1 的表达始终存在统计学意义上的显著升高。此外，我们的研究结果表明，BLV 感染通过维持 T 细胞中免疫检查点的高表达，延长了围产期奶牛的免疫抑制。此外，BLV 感染的奶牛在泌乳早期发生新乳腺炎的比例更高。因此，我们的研究提供了 BLV 对奶牛生命中最关键时期的免疫抑制作用的新见解，对保护性 T 细胞免疫和乳腺炎等合并症具有明显的不利影响。
