PDF(Pubmed)
Abstract：
Porcine respiratory disease is multifactorial and most commonly involves pathogen co-infections. Major contributors include swine influenza A (swIAV) and porcine reproductive and respiratory syndrome (PRRSV) viruses. Experimental co-infection studies with these two viruses have shown that clinical outcomes can be exacerbated, but how innate and adaptive immune responses contribute to pathogenesis and pathogen control has not been thoroughly evaluated. We investigated immune responses following experimental simultaneous co-infection of pigs with swIAV H3N2 and PRRSV-2. Our results indicated that clinical disease was not significantly exacerbated, and swIAV H3N2 viral load was reduced in the lung of the co-infected animals. PRRSV-2/swIAV H3N2 co-infection did not impair the development of virus-specific adaptive immune responses. swIAV H3N2-specific IgG serum titers and PRRSV-2-specific CD8β+ T-cell responses in blood were enhanced. Higher proportions of polyfunctional CD8β+ T-cell subset in both blood and lung washes were found in PRRSV-2/swIAV H3N2 co-infected animals compared to the single-infected groups. Our findings provide evidence that systemic and local host immune responses are not negatively affected by simultaneous swIAV H3N2/PRRSV-2 co-infection, raising questions as to the mechanisms involved in disease modulation.
摘要：
猪呼吸道疾病是多因素的，最常见的是病原体共感染。主要贡献者包括猪流感A(swIAV)和猪繁殖与呼吸综合征(PRRSV)病毒。这两种病毒的实验性共感染研究表明，临床结果可能会加剧，但是先天免疫和适应性免疫反应对发病机制和病原体控制的贡献尚未得到彻底评估。我们研究了猪与swIAVH3N2和PRRSV-2同时共感染后的免疫反应。我们的结果表明，临床疾病没有明显恶化，和swIAVH3N2病毒载量在共感染动物的肺中降低。PRRSV-2/swIAVH3N2共感染不会损害病毒特异性适应性免疫反应的发展。swIAVH3N2特异性IgG血清滴度和血液中PRRSV-2特异性CD8β+T细胞反应增强。与单次感染组相比，在PRRSV-2/swIAVH3N2共感染的动物中发现了更高比例的多功能CD8βT细胞亚群。我们的发现提供了证据，表明系统性和局部宿主免疫反应不会受到同时swIAVH3N2/PRRSV-2共感染的负面影响，对疾病调制的机制提出了质疑。
