Turlewicz-Podbielska Hanna, Czyżewska-Dors Ewelina, Pomorska-Mól Małgorzata
Department of Preclinical Sciences and Infectious Diseases, Faculty of Veterinary Medicine and Animal Science, Poznan University of Life Sciences, Wołyńska 35, 60-637, Poznań, Poland.
Department of Swine Diseases, National Veterinary Research Institute, Partyzantów 57, 24-100, Puławy, Poland.
BMC Vet Res. 2021 Jan 6;17(1):5. doi: 10.1186/s12917-020-02722-8.
Swine influenza A virus (IAV) and porcine reproductive and respiratory syndrome virus (PRRSV) are considered key viral pathogens involved in the porcine respiratory disease complex. Concerning the effect of one virus on another with respect to local immune response is still very limited. Determination of presence and quantity of cytokines in the lung tissue and its relation to the lung pathology can lead to a better understanding of the host inflammatory response and its influence on the lung pathology during single or multi-virus infection. The aim of the present study was to explore and compare the patterns of lung cytokine protein response in pigs after single or dual infection with swine IAV and/or PRRSV.
Inoculation with IAV alone causes an increase in lung concentration of IFN-α, IFN-ɣ, TNF-α, IL-6, IL-8 and IL-10, especially at 2 and 4 DPI. In PRRSV group, beyond early IFN-α, IFN-ɣ, IL-6, IL-8 and IL-10 induction, elevated levels of cytokines at 10 and 21 DPI have been found. In IAV+PRRSV inoculated pigs the lung concentrations of all cytokines were higher than in control pigs.
Current results indicate that experimental infection of pigs with IAV or PRRSV alone and co-infection with both pathogens induce different kinetics of local cytokine response. Due to strong positive correlation between local TNF-α and IL-10 concentration and lung pathology, we hypothesize that these cytokines are involved in the induction of lung lesions during investigates infection. Nevertheless, no apparent increase in lung cytokine response was seen in pigs co-inoculated simultaneously with both pathogens compared to single inoculated groups. It may also explain no significant effect of co-infection on the lung pathology and pathogen load, compared to single infections. Strong correlation between local concentration of TNF-α, IFN-ɣ, IL-8 and SwH1N1 load in the lung, as well as TNF-α, IL-8 and PRRSV lung titres suggested that local replication of both viruses also influenced the local cytokine response during infection.
甲型流感病毒（IAV）和猪繁殖与呼吸综合征病毒（PRRSV）被认为是猪呼吸道疾病综合征中的关键病毒病原体。关于一种病毒对另一种病毒局部免疫反应的影响，目前仍非常有限。测定肺组织中细胞因子的存在和数量及其与肺部病理的关系，有助于更好地理解宿主炎症反应及其在单一或多病毒感染期间对肺部病理的影响。本研究的目的是探索和比较猪在单独或双重感染猪IAV和/或PRRSV后肺细胞因子蛋白反应的模式。
单独接种IAV会导致肺中IFN-α、IFN-ɣ、TNF-α、IL-6、IL-8和IL-10浓度升高，尤其是在感染后第2天和第4天。在PRRSV组中，除了早期IFN-α、IFN-ɣ、IL-6、IL-8和IL-10的诱导外，在感染后第10天和第21天还发现细胞因子水平升高。在接种IAV+PRRSV的猪中，所有细胞因子的肺浓度均高于对照猪。
目前的结果表明，单独用IAV或PRRSV对猪进行实验性感染以及两种病原体的共同感染会诱导不同的局部细胞因子反应动力学。由于局部TNF-α和IL-10浓度与肺部病理之间存在强正相关，我们推测这些细胞因子在研究感染期间参与了肺部病变的诱导。然而，与单一接种组相比，同时接种两种病原体的猪肺部细胞因子反应未见明显增加。这也可能解释了与单一感染相比，共同感染对肺部病理和病原体载量没有显著影响。肺部局部TNF-α、IFN-ɣ、IL-8浓度与SwH1N1载量之间以及TNF-α、IL-8与PRRSV肺滴度之间的强相关性表明，两种病毒的局部复制也影响了感染期间的局部细胞因子反应。
