Crisci Elisa, Fraile Lorenzo, Montoya Maria
Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA.
Comparative Medicine Institute, North Carolina State University, Raleigh, NC 27607, USA.
Vet Sci. 2019 Mar 11;6(1):26. doi: 10.3390/vetsci6010026.
Porcine respiratory disease complex (PRDC) is a polymicrobial syndrome that results from a combination of infectious agents, such as environmental stressors, population size, management strategies, age, and genetics. PRDC results in reduced performance as well as increased mortality rates and production costs in the pig industry worldwide. This review focuses on the interactions of two enveloped RNA viruses-porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SwIV)-as major etiological agents that contribute to PRDC within the porcine cellular innate immunity during infection. The innate immune system of the porcine lung includes alveolar and parenchymal/interstitial macrophages, neutrophils (PMN), conventional dendritic cells (DC) and plasmacytoid DC, natural killer cells, and γδ T cells, thus the in vitro and in vivo interactions between those cells and PRRSV and SwIV are reviewed. Likewise, the few studies regarding PRRSV-SwIV co-infection are illustrated together with the different modulation mechanisms that are induced by the two viruses. Alterations in responses by natural killer (NK), PMN, or γδ T cells have not received much attention within the scientific community as their counterpart antigen-presenting cells and there are numerous gaps in the knowledge regarding the role of those cells in both infections. This review will help in paving the way for future directions in PRRSV and SwIV research and enhancing the understanding of the innate mechanisms that are involved during infection with these viruses.
猪呼吸道疾病综合征（PRDC）是一种由多种病原体引起的综合征，这些病原体包括环境应激源、猪群规模、管理策略、年龄和遗传因素等。PRDC导致全球养猪业的生产性能下降、死亡率上升和生产成本增加。本综述聚焦于两种包膜RNA病毒——猪繁殖与呼吸综合征病毒（PRRSV）和猪流感病毒（SwIV）——在感染过程中作为导致PRDC的主要病原体，在猪细胞固有免疫中的相互作用。猪肺的固有免疫系统包括肺泡和实质/间质巨噬细胞、中性粒细胞（PMN）、传统树突状细胞（DC）和浆细胞样DC、自然杀伤细胞以及γδT细胞，因此本文综述了这些细胞与PRRSV和SwIV之间的体外和体内相互作用。同样，本文还阐述了关于PRRSV-SwIV共感染的少数研究以及这两种病毒诱导的不同调节机制。自然杀伤（NK）细胞、PMN或γδT细胞反应的改变在科学界尚未受到太多关注，因为它们与对应的抗原呈递细胞不同，而且关于这些细胞在两种感染中的作用，仍存在许多知识空白。本综述将有助于为PRRSV和SwIV的未来研究方向铺平道路，并增进对这些病毒感染过程中所涉及的固有机制的理解。
