Guanylate-binding proteins (GBP1 and GBP5) are known to be important for host resistance against porcine reproductive and respiratory syndrome virus (PRRSV) infection. In this study, the effects of polymorphisms in GBP1 (GBP1E2 and WUR) and GBP5 on host immune responses against PRRSV were investigated to elucidate the mechanisms governing increased resistance to this disease. Seventy-one pigs [pre-genotyped based on three SNP markers (GBP1E2, WUR, and GBP5)] were assigned to homozygous (n = 36) and heterozygous (n = 35) groups and challenged with the JA142 PRRSV strain. Another group of nineteen pigs was kept separately as a negative control group. Serum and peripheral blood mononuclear cells (PBMCs) were collected at 0, 3, 7, 14, 21 and 28 days post-challenge (dpc). Viremia and weight gain were measured in all pigs at each time point, and a flow cytometry analysis of PBMCs was performed to evaluate T cell activation. In addition, 15 pigs (5 pigs per homozygous, heterozygous and negative groups) were sacrificed at 3, 14 and 28 dpc, and the local T cell responses were evaluated in the lungs, bronchoalveolar lavage cells (BALc), lymph nodes and tonsils. The heterozygous pigs showed lower viral loads in the serum and lungs and higher weight gains than the homozygous pigs based on the area under the curve calculation. Consistently, compared with the homozygous pigs, the heterozygous pigs exhibited significantly higher levels of IFN-α in the serum, proliferation of various T cells (γδT, Th1, and Th17) in PBMCs and tissues, and cytotoxic T cells in the lungs and BALc. These results indicate that the higher resistance in the pigs heterozygous for the GBP1E2, WUR and GBP5 markers could be mediated by increased antiviral cytokine (IFN-α) production and T cell activation.

中文翻译：

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猪鸟苷酸结合蛋白中的多态性对实验攻击猪的宿主对PRRSV感染的抵抗力的影响。

已知鸟苷酸结合蛋白（GBP1和GBP5）对于宿主抵抗猪繁殖与呼吸综合征病毒（PRRSV）感染的抵抗力很重要。在这项研究中，研究了GBP1（GBP1E2和WUR）和GBP5多态性对宿主针对PRRSV的免疫反应的影响，以阐明控制对该病抵抗力增强的机制。将71只猪[根据三种SNP标记（GBP1E2，WUR和GBP5进行预基因分型）]分为纯合组（n = 36）和杂合组（n = 35），并用JA142 PRRSV菌株攻击。另一组十九只猪作为阴性对照组单独饲养。在攻击后0、3、7、14、21和28天（dpc）收集血清和外周血单核细胞（PBMC）。在每个时间点测量所有猪的病毒血症和体重增加，并进行了PBMC的流式细胞术分析以评估T细胞活化。此外，分别在3、14和28 dpc处死15头猪（每只纯合子，杂合子和阴性组5头猪），并在肺，支气管肺泡灌洗细胞（BALc），淋巴结和扁桃体中评估局部T细胞反应。根据曲线计算的面积，与纯合猪相比，杂合猪在血清和肺中显示出较低的病毒载量，并且体重增加较高。始终如一，与纯合猪相比，杂合猪在血清中表现出明显更高的IFN-α水平，PBMC和组织中各种T细胞（γδT，Th1和Th17）的增殖以及肺和BALc中的细胞毒性T细胞。这些结果表明，猪对GBP1E2具有较高的抗性，