IL-1B signaling in dendritic cells induces antiviral interferon responses. IL-1B signaling in dendritic cells induces antiviral interferon responses

Activation of interferon-stimulated gene (ISG) responses is critical for control of viral infection. We recently identified that stimulation of the NLRP3 inflammasome and mobilization of the inflammatory cytokine IL-1β act as critical host restrictive pathways against West Nile virus (WNV) in a mechanism dependent on the regulation of ISGs. In order to define the mechanism by which IL-1β regulates these antiviral immune programs, we utilized global transcriptome analysis in myeloid cells, known targets of WNV replication to define gene signatures required for IL-1β driven antiviral responses. Surprisingly, we found IL-1β dependent activation of interferon-beta (IFN-β) and ISGs at late times following IL-1β treatment. Expression of these antiviral innate immune genes was found to be dependent on activation of IRF3 and appears to reflect a general shift in IL-1β signaling from an inflammatory response early following treatment to an anti-inflammatory type-I IFN mediated response at later times post-treatment. These data demonstrate that inflammatory and antiviral signals integrate to control viral infection. Strategies to co-opt these cytokine activated antiviral signatures can act as novel targeted therapeutic strategies tailored specifically to individual pathogens. Overall design: WT or IL-1R KO BMDCs were either mock-treated or pre-treated with 100 ng IL-1b for 24 hours. Cells were then either mock-infected or infected with WNV at an MOI of 2.5. Both mock and WNV-infected samples were harvested at 24 and 48 hours. WT BMDCs were also treated with IL-1b for 24 or 48 hours before harvest. All samples were run in triplicate. Total RNA was run on Agilent 4x44 mouse microarray Please note that the sample titles represent pre-treatment and infection status as following; sample group - pre-treatment - infection KO_MK_*hr - mock - mock KO_WNV_*hr - mock - WMV WT_IL1b_*hr - IL-1b - mock WT_MK_*hr - mock - mock WT_WNV_*hr - mock - WMV The *hr represents the time after infection.

干扰素刺激基因（interferon-stimulated gene, ISG）应答的激活对于病毒感染的防控至关重要。本团队近期发现，NLRP3炎性小体（NLRP3 inflammasome）的激活与炎性细胞因子IL-1β的动员，可通过依赖于ISG调控的分子机制，作为对抗西尼罗河病毒（West Nile virus, WNV）的关键宿主限制性通路。为阐明IL-1β调控此类抗病毒免疫程序的具体机制，我们在髓系细胞——已知的WNV复制靶标——中开展了全局转录组分析，以明确IL-1β介导的抗病毒应答所必需的基因特征谱。令人意外的是，我们观察到IL-1β处理后的晚期阶段，出现了IL-1β依赖的干扰素-β（IFN-β）与ISG的激活。此类抗病毒先天免疫基因的表达依赖于干扰素调节因子3（interferon regulatory factor 3, IRF3）的激活，这似乎反映了IL-1β信号通路的整体功能转变：从处理早期的促炎性应答，转向处理后晚期由I型干扰素介导的抗炎性应答。本研究数据证实，炎性信号与抗病毒信号相互整合以调控病毒感染。通过靶向利用此类细胞因子激活的抗病毒特征谱，可开发针对特定病原体的新型个体化靶向治疗策略。整体实验设计：野生型（wild type, WT）或IL-1R基因敲除（knockout, KO）的骨髓来源树突状细胞（bone marrow-derived dendritic cells, BMDCs）分别经空白对照（mock）处理，或用100 ng IL-1β预处理24小时。随后，细胞分别经mock感染，或以感染复数（multiplicity of infection, MOI）为2.5的WNV进行感染。空白对照感染与WNV感染的样本均于感染后24小时与48小时收获。此外，野生型BMDCs还分别经IL-1β处理24小时或48小时后收获。所有样本均设置3次生物学重复。总RNA经Agilent 4x44小鼠微阵列芯片进行检测。请注意样本命名规则如下，其命名代表预处理方式与感染状态：样本组名 - 预处理方案 - 感染状态KO_MK_*hr：mock预处理 - mock感染KO_WNV_*hr：mock预处理 - WMV感染WT_IL1b_*hr：IL-1β预处理 - mock感染WT_MK_*hr：mock预处理 - mock感染WT_WNV_*hr：mock预处理 - WMV感染其中*hr代表感染后的时间。