Zhang Wenli, Wang Xinrong, Zhang He, Pan Yu, Ma Wenjie, Xu Yunfei, Tian Zhijun, Xia Changyou, Fu Lizhi, Wang Yue
College of Veterinary Medicine, Southwest University, Chongqing, China.
Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.
J Virol. 2024 Nov 19;98(11):e0154223. doi: 10.1128/jvi.01542-23. Epub 2024 Oct 24.
Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly variable virus with genetic diversity. This study comparatively examines the pathogenicity and immunological impact of two emergent PRRSV strains, SD53 and HuN4, in piglets. Our results indicate that SD53 strain induces milder clinical syndromes and less severe tissue damage than HuN4, despite similar replication rates. Hematological tests showed less perturbations in peripheral blood cell profiles after SD53 infection, suggesting a less systemic impact. The neutrophil-to-lymphocyte ratio was notably lower in SD53-infected piglets, suggesting a less intense inflammatory reaction. Moreover, SD53 infection led to lower levels of pro-inflammatory cytokines, further supporting a less pronounced inflammatory profile. Both strains induced the production of PRRSV-specific antibodies. However, transcriptomic analysis of lung and lymph node tissues from infected piglets disclosed a more moderate up-regulation of core genes, including , in the SD53 group. Further analysis indicated that SD53 primarily enhanced immune-related signaling, particularly in T cell response modules, while HuN4 caused a more robust pro-inflammatory reaction and a dampening of T cell functionality. Flow cytometry analyses confirmed these findings, showing higher CD4/CD8 ratios and increased CD4+ T cell percentages in SD53-infected piglets, implying a more robust T cell response. Collectively, these findings broaden our comprehension of PRRSV pathogenesis and may inform the development of future therapeutic or prophylactic strategies for controlling PRRSV infections more effectively.
The high mutation rate of porcine reproductive and respiratory syndrome virus (PRRSV) poses significant challenges to its accurate diagnosis and the implementation of effective control measures. This research explores the pathogenic profiles of two emerging PRRSV stains: the NADC30-like strain SD53 and the highly pathogenic strain HuN4. Our investigation reveals that SD53 initiates distinct immunopathological responses compared with those provoked by HuN4. By conducting a transcriptome analysis of differential gene expression in the lungs and lymph nodes of infected piglets, we unveil the intricate molecular mechanisms underlying the contrasting pathogenicity of these two strains. The comprehensive insights yielded by this study are instrumental in advancing our understanding of the dominant NADC30-like PRRSV strain, which has become increasingly prevalent in China's swine industry.
猪繁殖与呼吸综合征病毒（PRRSV）是一种具有遗传多样性的高度可变病毒。本研究比较了两种新兴PRRSV毒株SD53和HuN4对仔猪的致病性和免疫影响。我们的结果表明，尽管复制率相似，但SD53毒株比HuN4诱导的临床综合征更轻，组织损伤也更不严重。血液学检测显示，SD53感染后外周血细胞谱的扰动较小，表明其对全身的影响较小。SD53感染的仔猪中性粒细胞与淋巴细胞比率显著较低，表明炎症反应较弱。此外，SD53感染导致促炎细胞因子水平较低，进一步支持了炎症反应不明显的特征。两种毒株均诱导产生PRRSV特异性抗体。然而，对感染仔猪的肺和淋巴结组织进行转录组分析发现，SD53组核心基因（包括……）的上调更为适度。进一步分析表明，SD53主要增强免疫相关信号，特别是在T细胞反应模块中，而HuN4则引起更强的促炎反应并抑制T细胞功能。流式细胞术分析证实了这些发现，显示SD53感染的仔猪中CD4/CD8比率更高，CD4 + T细胞百分比增加，这意味着T细胞反应更强。总体而言，这些发现拓宽了我们对PRRSV发病机制的理解，并可能为未来更有效地控制PRRSV感染的治疗或预防策略的制定提供参考。
猪繁殖与呼吸综合征病毒（PRRSV）的高突变率对其准确诊断和有效控制措施的实施构成了重大挑战。本研究探讨了两种新兴PRRSV毒株的致病特征：NADC30样毒株SD53和高致病性毒株HuN4。我们的研究表明，与HuN4引发的免疫病理反应相比，SD53引发的免疫病理反应不同。通过对感染仔猪肺和淋巴结中差异基因表达进行转录组分析，我们揭示了这两种毒株致病性差异背后复杂的分子机制。本研究产生的全面见解有助于推进我们对在中国养猪业中日益普遍的优势NADC30样PRRSV毒株的理解。
