Yang Ning, Li Jiandong, Yang Qian, Qiao Jinzeng, Cui Defeng, Liu Fenghua, Li Huanrong, Zhou Shuanghai
College of Animal Science and Technology, Beijing Key Laboratory of TCVM, Beijing University of Agriculture, No. 7 Beinong Road, Changping District, Beijing, 102206, China.
Arch Virol. 2018 May;163(5):1231-1239. doi: 10.1007/s00705-018-3735-8. Epub 2018 Feb 3.
The efficiency of immune responses and host defense against pathogens largely depends on the function of dendritic cells (DCs). Porcine circovirus type 2 (PCV2) infection causes viremia and extensive modulation of immune activities in the blood. The objective of the present study was to investigate the effects of PCV2 infection in vivo on the immunological function of DCs induced from peripheral blood monocytes (MoDCs). At different points after infection with PCV2, peripheral blood monocytes from PCV2-infected pigs were used to induce differentiation of DCs in vitro. Flow cytometry and quantitative real-time reverse transcription PCR were conducted to detect mRNA expression of surface markers related to antigen presentation and inflammatory/immunosuppressive cytokines of the induced MoDCs. The ability of induced MoDCs to stimulate T cells was measured using an MTS assay. In the early phase of infection at 3 days post-inoculation (DPI), IL-10, IL-8 and MIP-1β in MoDCs were upregulated significantly. By the peak of virus proliferation at 7 DPI, antigen presentation molecules SLA-DR (MHC II) and CD80/86 together with cytokines IL-12 and IL-10 had decreased, accompanied by a rapid reduction of IL-8 and MIP-1β. The T cell stimulation index of induced MoDCs in PCV2 groups after different infection times declined to some extent, with a significant difference at 7 DPI. PCV2 infection in vivo functionally reduced the antigen presentation capability of induced MoDCs from peripheral blood and modified expression of inflammatory/immunosuppressive cytokines that may be related to PCV2-induced immunosuppression.
免疫反应的效率以及宿主对病原体的防御在很大程度上取决于树突状细胞（DCs）的功能。猪圆环病毒2型（PCV2）感染会导致病毒血症以及血液中免疫活动的广泛调节。本研究的目的是调查PCV2体内感染对由外周血单核细胞诱导产生的树突状细胞（MoDCs）免疫功能的影响。在PCV2感染后的不同时间点，使用来自PCV2感染猪的外周血单核细胞在体外诱导树突状细胞分化。采用流式细胞术和定量实时逆转录PCR检测诱导产生的MoDCs中与抗原呈递相关的表面标志物以及炎性/免疫抑制细胞因子的mRNA表达。使用MTS检测法测定诱导产生的MoDCs刺激T细胞的能力。在接种后3天（DPI）的感染早期，MoDCs中的IL-10、IL-8和MIP-1β显著上调。到病毒增殖高峰期的7 DPI时，抗原呈递分子SLA-DR（MHC II）和CD80/86以及细胞因子IL-12和IL-10减少，同时IL-8和MIP-1β迅速降低。不同感染时间后PCV2组中诱导产生的MoDCs的T细胞刺激指数在一定程度上下降，在7 DPI时有显著差异。PCV2体内感染在功能上降低了外周血诱导产生的MoDCs的抗原呈递能力，并改变了可能与PCV2诱导的免疫抑制相关的炎性/免疫抑制细胞因子的表达。
