Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
Viruses. 2019 Aug 29;11(9):796. doi: 10.3390/v11090796.
Porcine reproductive and respiratory syndrome virus (PRRSV) continues to cause severe reproductive and respiratory pathologies resulting in immense monetary and welfare costs for the swine industry. The vaccines against PRRSV are available; but they struggle with providing protection against the plethora of heterologous PRRSV strains. To improve PRRSV vaccine development, the aim of this study was to provide an in-depth analysis of the crucial heterologous T-cell response to type-2 PRRSV. Following PRRSV modified live virus (MLV) vaccination or infection using one high- or one low-pathogenic PRRSV-strain, this nine-week study evaluated the T-cell response to different PRRSV strains. Our results demonstrate an important role for T cells in this homo- and heterologous response. Specifically, the T-helper cells were the main responders during viremia. Their peak response at 28 dpi correlated with a reduction in viremia, and their homing receptor expression indicated the additional importance for the anti-PRRSV response in the lymphatic and lung tissue. The cytocoxic T lymphocyte (CTL) response was the strongest at the site of infection-the lung and bronchoalveolar lavage. The TCR-γδ T cells were the main responders post viremia and PRRSV induced their expression of the lymph node homing the chemokine receptor, CCR7: This indicates a crucial role for TCR-γδ T cells in the anti-PRRSV response in the lymphatic system.
猪繁殖与呼吸综合征病毒（PRRSV）持续引起严重的生殖和呼吸道疾病，给养猪业带来巨大的经济和福利成本。目前已有针对 PRRSV 的疫苗，但它们在预防多种异源 PRRSV 毒株方面存在困难。为了改进 PRRSV 疫苗的开发，本研究旨在深入分析 2 型 PRRSV 的关键异源 T 细胞反应。在使用一种高致病性或一种低致病性 PRRSV 毒株进行 PRRSV 改良活病毒（MLV）接种或感染后，这项为期九周的研究评估了对不同 PRRSV 毒株的 T 细胞反应。我们的研究结果表明 T 细胞在同源和异源反应中起着重要作用。具体而言，辅助性 T 细胞是病毒血症期间的主要反应者。它们在 28dpi 时的峰值反应与病毒血症的减少相关，其归巢受体表达表明它们在淋巴组织和肺部的抗 PRRSV 反应中具有额外的重要性。细胞毒性 T 淋巴细胞（CTL）反应在感染部位（肺部和支气管肺泡灌洗液）最强。TCR-γδ T 细胞是病毒血症后和 PRRSV 诱导其表达的主要反应者，淋巴节点归巢趋化因子受体 CCR7：这表明 TCR-γδ T 细胞在淋巴系统中的抗 PRRSV 反应中起着关键作用。
