The cGAS-STING-interferon regulatory factor 7 pathway regulates neuroinflammation in Parkinson's disease

Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report that interferon regulatory factor 7 is markedly up-regulated in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease and co-localizes with microglial cells.Both the selective cyclic guanosine monophosphate adenosine monophosphate synthase inhibitor RU.521 and the stimulator of interferon genes inhibitor H151 effectively suppressed interferon regulatory factor 7 activation in BV2 microglia exposed to 1-methyl-4-phenylpyridinium and inhibited transformation of mouse BV2 microglia into the neurotoxic M1 phenotype.In addition,si RNA-mediated knockdown of interferon regulatory factor 7 expression in BV2 microglia reduced the expression of inducible nitric oxide synthase,tumor necrosis factorα,CD16,CD32,and CD86 and increased the expression of the anti-inflammatory markers ARG1 and YM1.Taken together,our findings indicate that the cyclic guanosine monophosphate adenosine monophosphate synthase-stimulator of interferon genes-interferon regulatory factor 7 pathway plays a crucial role in the pathogenesis of Parkinson's disease.

PLP2, a potent deubiquitinase from murine hepatitis virus, strongly inhibits cellular type I interferon production

Infections by coronaviruses such as severe acute respiratory syndrome （SARS） coronavirus （SCoV） and mouse hepatitis virus A59 （MHV-A59） result in very little type I interferon （IFN） production by host cells, which is potentially responsible for the rapid viral growth and severe immunopathology associated with SARS. However, the molecular mechanisms for the low IFN production in cells infected with coronaviruses remain unclear. Here, we provide evidence that Papain-like protease domain 2 （PLP2）, a catalytic domain of the nonstructural protein 3 （nsp3） of MHV-A59, can bind to IRF3, cause its deubiquitination and prevent its nuclear translocation. As a consequence, co-expression of PLP2 strongly inhibits CARDIF-, TBK1- and IRF3-mediated IFNp reporter activities. In addition, we show that wild-type PLP2 but not the mutant PLP2 lacking the deubiquitinase （DUB） activity can reduce IFN induction and promote viral growth in cells infected with VSV. Thus, our study uncovered a viral DUB which coronaviruses may use to escape from the host innate antiviral responses.

The host type I interferon response to viral and bacterial infections

Type I interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type I IFNsare produced following viral infections, but until recently, the mechanisms of viral recognition leading to IFN productionwere largely unknown. Toll like receptors (TLRs) have emerged as key transducers of type I IFN during viral infectionsby recognizing various viral components. Furthermore, much progress has been made in defining the signaling path-ways downstream of TLRs for type I IFN production. TLR7 and TLR9 have become apparent as universally importantin inducing type I IFN during infection with most viruses, particularly by plasmacytoid dendritic cells. New intracellularviral pattern recognition receptors leading to type I IFN production have been identified. Many bacteria can also inducethe up-regulation of these cytokines. Interestingly, recent studies have found a detrimental effect on host cells if type IIFN is produced during infection with the intracellular gram-positive bacterial pathogen, Listeria monocytogenes. Thisreview will discuss the recent advances made in defining the signaling pathways leading to type I IFN production.

IRF family proteins and type I interferon induction in dendritic cells

Dendritic cells （DC）, although a minor population in hematopoietic cells, produce type I interferons （IFN） and other cytokines and are essential for innate immunity. They are also potent antigen presenters and regulate adaptive immunity. Among DC subtypes plasmacytoid DC （pDC） produce the highest amounts of type I IFN. In addition, pro- and anti-inflammatory cytokines such as IL-12 and IL-10 are induced in DC in response to Toll like receptor （TLR） signaling and upon viral infection. Proteins in the IRF family control many aspects of DC activity. IRF-8 and IRF-4 are essential for DC development. They differentially control the development of four DC subsets. IRF-8^-/- mice are largely devoid of pDC and CD8α^＋ DC, while IRF-4^-/- mice lack CD4^＋ DC. IRF-8^-/-, IRF4^-/-, double knock-out mice have only few CD8α CD4^-DC that lack MHC Ⅱ. IRF proteins also control type Ⅰ IFN induction in DC. IRF-7, activated upon TLR signaling is required for IFN induction not only in pDC, but also in conventional DC （cDC） and non-DC cell types. IRF-3, although contributes to IFN induction in fibroblasts, is dispensable in IFN induction in DC. Our recent evidence reveals that type Ⅰ IFN induction in DC is critically dependent on IRF-8, which acts in the feedback phase of IFN gene induction in DC. Type Ⅰ IFN induction in pDC is mediated by MyD88 dependent signaling pathway, and differs from pathways employed in other cells, which mostly rely on TLR3 and RIG-Ⅰ family proteins. Other pro-inflammatory cytokines are produced in an IRF-5 dependent manner. However, IRF-5 is not required for IFN induction, suggesting the presence of separate mechanisms for induction of type Ⅰ IFN and other pro-inflammatory cytokines. IFN and other cytokines produced by activated DC in turn advance DC maturation and change the phenotype and function of DC. These processes are also likely to be governed by IRF family proteins.

A functional type I interferon pathway drives resistance to cornea herpes simplex virus type 1 infection by recruitment of leukocytes

Type I interferons are critical antiviral cytokines produced following herpes simplex virus type-1 （HSV-1） infection that act to inhibit viral spread. In the present study, we identify HSV-infected and adjacent uninfected corneal epithelial cells as the source of interferon-a. We also report mice deficient in the A1 chain of the type I IFN receptor （CDl18-/） are extremely sensitive to ocular infection with low doses （100 PFU） of HSV-1 as seen by significantly elevated viral titers in the cornea Compared to wild type （WT） controls. The enhanced susceptibil- ity correlated with a loss of CD4＋ and CD8＋ T cell recruitment and aberrant chemokine production in the cornea despite mounting an adaptive immune response in the draining mandibular lymph node of CDll8/ mice. Taken together, these results highlight the importance of IFN production in both the innate immune response as well as eliciting chemokine production required to facilitate adaptive immune cell trafficking.

PEDV结构蛋白颉颃IFN-Ⅰ应答的分子机制研究进展

猪流行性腹泻(porcine epidemic diarrhea,PED)具有很高的发病率和死亡率,尤其是在猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)高致病性变异株(GⅡ型毒株)出现以来,更是对全球养猪业构成了巨大威胁。病毒感染宿主之后,宿主会激活抗病毒天然免疫应答机制。干扰素(interferon,IFN)作为一类抵御病毒感染的关键分子,特别是Ⅰ型干扰素(IFN-Ⅰ)可通过激活各种免疫细胞和共刺激分子来颉颃病毒的增殖。与此同时,为实现在宿主内的持续复制,许多病毒建立了颉颃宿主机体IFN-Ⅰ应答的多种分子机制,进而实现免疫逃逸。PEDV编码的多种结构蛋白可以颉颃宿主IFN-Ⅰ免疫应答。文章综述了PEDV结构蛋白颉颃IFN-Ⅰ免疫应答的分子机制,以期为深入阐释PEDV免疫逃逸的分子机制与开发PEDV新型靶向药物和建立防控新策略提供科学参考。

Fangchinoline induces antiviral response by suppressing STING degradation

The stimulator of interferon genes(STING),an integral adaptor protein in the DNA-sensing pathway,plays a pivotal role in the innate immune response against infections.Additionally,it presents a valuable therapeutic target for infectious diseases and cancer.We observed that fangchinoline(Fan),a bis-benzylisoquinoline alkaloid(BBA),effectively impedes the replication of vesicular stomatitis virus(VSV),encephalomyocarditis virus(EMCV),influenza A virus(H1N1),and herpes simplex virus-1(HSV-1)in vitro.Fan treatment significantly reduced the viral load,attenuated tissue inflammation,and improved survival in a viral sepsis mouse model.Mechanistically,Fan activates the antiviral response in a STING-dependent manner,leading to increased expression of interferon(IFN)and interferon-stimulated genes(ISGs)for potent antiviral effects in vivo and in vitro.Notably,Fan interacts with STING,preventing its degradation and thereby extending the activation of IFN-based antiviral responses.Collectively,our findings highlight the potential of Fan,which elicits antiviral immunity by suppressing STING degradation,as a promising candidate for antiviral therapy.

Emerging mechanisms and implications of c GAS-STING signaling in cancer immunotherapy strategies

The intricate interplay between the human immune system and cancer development underscores the central role of immunotherapy in cancer treatment.Within this landscape,the innate immune system,a critical sentinel protecting against tumor incursion,is a key player.The cyclic GMP-AMP synthase(c GAS)and stimulator of interferon genes(STING)pathway has been found to be a linchpin of innate immunity:activation of this signaling pathway orchestrates the production of type I interferon(IFN-α/β),thus fostering the maturation,differentiation,and mobilization of immune effectors in the tumor microenvironment.Furthermore,STING activation facilitates the release and presentation of tumor antigens,and therefore is an attractive target for cancer immunotherapy.Current strategies to activate the STING pathway,including use of pharmacological agonists,have made substantial advancements,particularly when combined with immune checkpoint inhibitors.These approaches have shown promise in preclinical and clinical settings,by enhancing patient survival rates.This review describes the evolving understanding of the c GAS-STING pathway's involvement in tumor biology and therapy.Moreover,this review explores classical and non-classical STING agonists,providing insights into their mechanisms of action and potential for optimizing immunotherapy strategies.Despite challenges and complexities,the c GAS-STING pathway,a promising avenue for enhancing cancer treatment efficacy,has the potential to revolutionize patient outcomes.

紫正地黄合剂对RSV上呼吸道感染小鼠Ⅰ型干扰素及ISG表达的影响

目的:探讨紫正地黄合剂对呼吸道合胞病毒(RSV)上呼吸道感染小鼠Ⅰ型干扰素及ISG表达的影响。方法:将36只Balb/c小鼠随机分为空白组(A组)、模型组(B组)、紫正地黄合剂低剂量组(C组)、紫正地黄合剂中剂量组(D组)、紫正地黄合剂高剂量组(E组)和利巴韦林组(F组),每组6只。RSV滴鼻3 d造模成功后,C组、D组、E组分别使用180.0 mg/(kg·d)、360.0 mg/(kg·d)、720.0 mg/(kg·d)紫正地黄合剂灌胃,F组使用27.6 mg/(kg·d)利巴韦林灌胃。各组均以生理盐水配置为200μL灌胃。A组、B组给予等容量生理盐水200μL灌胃,1次/d,连续3 d。灌胃干预72 h后,以小鼠鼻咽组织为样本,分别采用酶联免疫吸附试验(ELISA)检测血清IFN-α、IFN-β水平;HE观察病理情况;IHC检测RSV-F蛋白和干扰素刺激基因(ISG)蛋白表达;RT-PCR检测RSV mRNA及ISG mRNA表达水平。结果:与A组比较,其余各组小鼠血清IFN-α、IFN-β含量均升高(P<0.01);与B组比较,C组、D组、E组、F组小鼠血清IFN-α、IFN-β含量均升高(P<0.01);E组与F组小鼠血清IFN-α、IFN-β含量比较,差异均无统计学意义(P>0.05)。A组小鼠鼻咽组织结构正常,无病毒颗粒及炎症改变;B组小鼠鼻咽组织黏膜上皮大量病毒颗粒及病毒包涵体,炎症较重。C组、D组、E组小鼠鼻咽组织黏膜上皮病毒颗粒、增生及炎症情况均逐渐减轻,且均较B组轻。F组小鼠鼻咽组织黏膜上皮结构仍有破损,见少量上皮增生及炎症细胞,少量病毒颗粒。造模组均可见小鼠鼻咽组织RSV-F蛋白和ISG蛋白抗原。B组小鼠鼻咽组织上皮细胞及腺泡间广泛感染,纤毛脱落。与B组比较,C组、D组、E组可见上皮细胞少量感染;F组较B组感染情况明显减轻。与B组比较,其余各组小鼠鼻咽组织RSV m RNA和ISG mRNA明显表达(P<0.01);与B组比较,C组、D组、E组、F组小鼠鼻咽组织RSV mRNA表达均减少(P<0.01),D组、E组、F组ISG mRNA表达均增加(P<0.01);与C组、D组比较,F组小鼠鼻咽组织RSV m RNA表达降低更显著(P<0.01);E组与F组小鼠鼻咽组织RSV mRNA和ISG mRNA比较,差异均无统计学意义(P>0.05)。结论:紫正地黄合剂可改善RSV感染小鼠上呼吸道炎症,降低鼻咽组织RSV载量,并通过上调信号通路中Ⅰ型干扰素及ISG的表达来调控机体免疫应答发挥抗病毒作用,提示紫正地黄合剂具有抗RSV、控制RSV上呼吸道感染的作用。

Effect of Sishen pill on expression of type Ⅰ and type Ⅲ interferon in acute ulcerative colitis mice model

Objective:To investigate the effects of Sishen pill on the expression of type I interferon(IFN)and type III interferon and their receptors in colonic tissues of mice with acute ulcerative colitis(UC).Methods:Male C57BL/6Cnc mice were randomly divided into control group,model group,sishenwan group and salazosulfapyridine group.The model was made with 0.2 mL 4%dextran sodium sulfate(DSS)for 5 days,and the control group was given 0.2mL normal saline by gavage.On the second day of modeling,sishen pill group was given 0.2mL 1.5 g·kg^(-1) sishen pill,and SASP group was given 0.2mL 0.25 g·kg^(-1) sulfasalazine,twice a day,for 7 days.During the administration period,the disease activity index(DAI)of mice was calculated every day.After administration,the histopathological changes of colon tissues of mice in each group were observed by hematoxylin eosin(HE)staining,and the histological scores were calculated.The expression of IFN-α,IFN-β,IFN-λ2 and IFN-λ3 mRNAs in colon tissues of mice in each group were detected by qRT-PCR.The expression levels of IFN-α,IFN-β,IFN-λ2 and IFN-λ3 in colon tissues of mice in each group were detected by ELISA.Western blot was used to detect the expression of interferon receptors IFNAR1,IFNAR2 and IFNLR1 in colon tissues of mice in each group.Results:Compared with the control group,the DAI of mice increased significantly(P<0.001)in the model group.The inflammatory cells in colonic tissues infiltrated heavily,lymph nodes enlarged,colonic mucosal structure destroyed,crypt structure lost,inflammation involved a wide range,and the histological score increased significantly(P<0.001).The levels of IFN-α,IFN-βand IFNλ2 mRNA were significantly decreased(P<0.05,P<0.05,P<0.01).The expression levels of IFN-α,IFN-β,IFN-λ2 and IFN-λ3 were significantly decreased(P<0.01,P<0.01,P<0.001,P<0.001).The levels of IFNAR1,IFNAR2 and IFNLR1 were significantly decreased(P<0.01,P<0.05,P<0.01).Compared with the model group,the DAI decreased significantly(P<0.001)in Sishen pill group,the infiltration of inflammatory cells in colon tissue were significantly reduced,the structural regeneration of colon mucosa was significantly recovered,the crypt structure was significantly recovered,the lymph nodes were significantly reduced,the range of inflammation involvement was reduced,and the histological score was significantly reduced(P<0.001).The levels of IFN-α,IFN-βand IFN-λ2 mRNA were significantly increased(P<0.01,P<0.001,P<0.001).The levels of IFN-α,IFN-β,IFN-λ2 and IFN-λ3 were significantly increased(P<0.01,P<0.001,P<0.01,P<0.001).The levels of IFNAR1,IFNAR2 and IFNLR1 were significantly increased(P<0.05,P<0.001,P<0.05).Conclusion:Sishen pill may alleviate the symptoms and signs of mice with acute ulcerative colitis by regulating the expression of type I and type III interferon and their receptors in colon tissues.

Higher Type 1 Interferon Levels in Plasma of Asymptomatic HIV-2 than in HIV-1 Individuals

A number of cytokines are secreted during HIV infection that enhances both innate and adaptive immune responses. Interferon-α/β/γ, IL-12, IL-15 and IL-18 have been found to contribute to the development, maturation, differentiation and function of NK and other immune cells. The levels of IFN-α/β/γ, IL-12, IL-15 and IL-18 were compared in the plasma of 90 HIV-1 infected and 90 HIV-2 infected subjects by ELISA or Cytometric Beads Array assays. The HIV-infected subjects were stratified according to CD4+ T cell counts into three groups: >500, 200 - 500 and <200 cells/ul, with 30 subjects in each group. Cytokine levels were also determined in the plasma of 50 HIV uninfected blood bank donors. Among the cytokines tested, IFN-α was found to be significantly increased in HIV-2 infected compared to HIV-1 infected subjects at high CD4+ T cell counts (p = 0.001). The levels of IFN-β were seen to differ between the two infections in patients from the category of medium CD4+ T cell counts: this was significantly increased in HIV-2 infected patients (p < 0.001) as well as compared to uninfected controls (p = 0.001). The levels of IFN-γ were similar at all the CD4+ T cell categories except for an increase in HIV-2 infected patients at low CD4+ T cell counts (p = 0.02). The levels of these cytokines were similar in all HIV-1 subjects. Also, the level of IL-12p70 was similar between the two infections but significantly higher in HIV-2 at low compared to medium CD4+ T cells categories (p = 0.047). Similar to IFN-γ and IL-12p70, the levels of both IL-18 and IL-15 were found to be significantly higher in HIV-2 infected patients compared to HIV-1 at low CD4+ T cell counts (p < 0.05). These data show that there is variability in the levels of innate cytokines at different stages of HIV infection but the finding of increased IFN-α in HIV-2 infected asymptomatic subjects is consistent with the high innate NK responses previously noted at this stage of infection.

Assessment of natural and interleukin-2-induced production of interferon-gamma in patients with liver diseases

AIMS To clarify whether the lower interferon gamma (IFNγ) production by lymphocytes in patients with liver diseases is due to defects of lymphocytes themselves or of other cofactors such as interleukin-2(IL-2). METHODS Peripheral blood mononuclear cells (PBMCs) from patients with various liver diseases were cultured with or without PHA and IL-2. The cells were harvested and counted and the su- pernatants were tested for IFNγ by a sensitive and quantitative ABC-ELISA. RESULTS IFNγ was not round in serum samples from patients as well as normal individuals. However,in supernatants of non-in- duced and induced PBMCs,IFN7 was detected by ABC-ELISA. In non-induced PBMCs (group 1),the content of IFNγ in super- natants from control,CAH,CPH and HCC was 8.72 μg/L, 5.03 μg/L,6.02 μg/L and 4.91 μg/L respectively. The pro- duction of IFNγ in liver disease was significantly decreased,com- pared to control. In group 2 in which PBMCs were stimulated with PHA,the content of IFNγ was 22.71,17.12,14.54 and 17.63 μg/L respectively. In group 3 in which PBMCs were in- duced by IL-2,the amount of IFN7 in supernatant from control (60.67 μg/L) was much larger than those from CAH (21.70 μg/ L),CPH (24.00 μg/L) and HCC (19.15 μg/L) (P<0.01). Comparing the amount of IFNγ in group 3 (IL-2-induced) with that in group 1 (non-induced),we found that IFNγ production was en- hanced by nearly 4 folds in liver diseases and by over 7 folds in control,Whereas the number of PBMCs,whether from liver dis- eases or from control,was increased by only approximately 3 folds. CONCLUSIONS The decreased production of IFNγ in liver dis- eases including HCC is mainly due to endogenous defects of lym- phocytes though the defects of stimulating cofactors such as IL-2 may also be involved.

Effects of γ interferon on hepatic fibrosis of schistosoma japonicum infected mice *

AIM To probe the effect of γ IFN on hepatic fibrosis in schistosomiasis japonica.

Type I interferon pathway in pediatric systemic lupus erythematosus

Background The role of type I interferon(IFN-I)signaling in systemic lupus erythematosus(SLE)has been well established.However,unanswered questions remain regarding the applicability of these findings to pediatric-onset SLE.The aim of this review is to provide an overview of the novel discoveries on IFN-I signaling in pediatric-onset SLE.Data sources A literature search was conducted in the PubMed database using the following keywords:“pediatric systemic lupus erythematosus”and“type I interferon”.Results IFN-I signaling is increased in pediatric SLE,largely due to the presence of plasmacytoid dendritic cells and pathways such as cyclic GMP-AMP synthase–stimulator of interferon genes–TANK-binding kinase 1 and Toll-like receptor(TLR)4/TLR9.Neutrophil extracellular traps and oxidative DNA damage further stimulate IFN-I production.Genetic variants in IFN-I-related genes,such as IFN-regulatory factor 5 and tyrosine kinase 2,are linked to SLE susceptibility in pediatric patients.In addition,type I interferonopathies,characterized by sustained IFN-I activation,can mimic SLE symptoms and are thus important to distinguish.Studies on interferonopathies also contribute to exploring the pathogenesis of SLE.Measuring IFN-I activation is crucial for SLE diagnosis and stratification.Both IFNstimulated gene expression and serum IFN-α2 levels are common indicators.Flow cytometry markers such as CD169 and galectin-9 are promising alternatives.Anti-IFN therapies,such as sifalimumab and anifrolumab,show promise in adult patients with SLE,but their efficacy in pediatric patients requires further investigation.Janus kinase inhibitors are another treatment option for severe pediatric SLE patients.Conclusions This review presents an overview of the IFN-I pathway in pediatric SLE.Understanding the intricate relationship between IFN-I and pediatric SLE may help to identify potential diagnostic markers and targeted therapies,paving the way for improved patient care and outcomes.

TRIM37对猪繁殖与呼吸综合征病毒复制及IFN-β产生影响的研究

本实验室前期通过质谱分析筛选到宿主因子三方基序蛋白37(TRIM37),推测其可能与猪繁殖与呼吸综合征病毒(PRRSV)的复制相关。为探究TRIM37对PRRSV复制的影响,本研究将不同剂量的PRRSV HN07-1株(MOI分别为0.01、0.1、1)分别感染猪肺泡巨噬细胞(PAM)和MARC-145细胞后不同时间(6 h、12 h、24 h、36 h和48 h),采用荧光定量PCR(qPCR)检测细胞中内源TRIM37的转录水平,结果显示PRRSV能够刺激这两种细胞内源TRIM37的转录,并且PRRSV以MOI 1及感染后24 h细胞中TRIM37的转录水平最高,感染后36 h和48 h细胞中TRIM37的转录水平较感染后24 h有所下降但仍显著高于对照组(P<0.05)。从MARC-145细胞中经PCR扩增TRIM37基因并克隆至pCAGGS-HA中构建真核表达质粒pCAGGS-HA-TRIM37,经双酶切及测序鉴定正确后转染MARC-145细胞,24 h后以MOI 1将HN07-1株感染细胞,感染后不同时间分别采用qPCR、western blot、病毒滴度(TCID50)测定和间接免疫荧光试验(IFA)检测PRRSV的复制情况。结果显示,与转染空载体pCAGGS-HA的对照细胞相比,过表达TRIM37后细胞中PRRSV ORF7的转录水平、N蛋白的表达水平(感染后48 h和72 h)及病毒滴度(感染后36 h与48 h)均显著(P<0.05)或者极显著(P<0.01)下降。针对TRIM37基因设计3对特异性的TRIM37 siRNA-1/2/3,转染MARC-145细胞后,利用qPCR检测TRIM37 siRNA的干扰效率,结果显示,TRIM37 siRNA-2能够有效降低TRIM37的转录水平。将TRIM37 siRNA-2转染MARC-145细胞后再以MOI 1 HN07-1株感染,感染后不同时间分别采用qPCR、western blot和病毒滴度(TCID50)测定检测PRRSV的复制情况。结果显示,与转染NC siRNA的对照细胞相比,干扰TRIM37表达的细胞中PRRSV ORF7的转录水平、N蛋白的表达水平及病毒滴度均显著(P<0.05)或极显著(P<0.01)升高。进一步将不同剂量的pCAGGS-HA-TRIM37与报告质粒pRL-TK-Luc和pIFN-β-Luc共转染HEK293T细胞;同时将不同剂量的pCAGGS-HA-TRIM37与报告质粒pRL-TK-Luc和pISRE-Luc共转染HEK293T细胞,18 h后加入poly(I:C)处理上述各组细胞,6 h后利用双荧光素酶试剂盒检测各组细胞中IFN-β和ISRE启动子的活性。将pCAGGS-HA-TRIM37转染HEK293T细胞,18 h后加入poly(I:C)处理细胞,6 h后采用qPCR检测细胞中相关干扰素刺激基因(ISG)(ISG15、CXCL10、MX1和OAS1)相对转录水平。双荧光素酶试验结果显示,与转染空载体的对照细胞相比,过表达TRIM37显著上调细胞中poly(I:C)激活的IFN-β和ISRE启动子的活性(P<0.05),且这种上调作用具有剂量依赖性。qPCR结果显示,与转染空载体的对照细胞相比,过表达TRIM37显著上调细胞中poly(I:C)激活的ISG15、CXCL10、MX1和OAS1 mRNA的转录水平(P<0.05)。本研究首次表明TRIM37能够通过促进细胞中相应干扰素的表达抑制PRRSV复制,该结果丰富了病毒感染过程中PRRSV-宿主相互作用的网络和机制,深化了对PRRSV致病机制的认知。

Role of nucleic acid sensing in the pathogenesis of type 1 diabetes

During infections,nucleic acids of pathogens are also engaged in recognition via several exogenous and cytosolic pattern recognition receptors,such as the toll-like receptors,retinoic acid inducible gene-I-like receptors,and nucleotide-binding and oligomerization domain-like receptors.The binding of the pathogen-derived nucleic acids to their corresponding sensors initiates certain downstream signaling cascades culminating in the release of type-I interferons(IFNs),especially IFN-αand other cytokines to induce proinflammatory responses towards invading pathogens leading to their clearance from the host.Although these sensors are hardwired to recognize pathogen associated molecular patterns,like viral and bacterial nucleic acids,under unusual physiological conditions,such as excessive cellular stress and increased apoptosis,endogenous self-nucleic acids like DNA,RNA,and mitochondrial DNA are also released.The presence of these self-nucleic acids in extranuclear compartments or extracellular spaces or their association with certain proteins sometimes leads to the failure of discriminating mechanisms of nucleic acid sensors leading to proinflammatory responses as seen in autoimmune disorders,like systemic lupus erythematosus,psoriasis and to some extent in type 1 diabetes(T1D).This review discusses the involvement of various nucleic acid sensors in autoimmunity and discusses how aberrant recognition of self-nucleic acids by their sensors activates the innate immune responses during the pathogenesis of T1D.

cGAS-STING通路异常激活及其抑制剂在免疫和炎症疾病中的研究进展

cGAS-STING通路是针对多种类型病原体进行免疫防御的主要途径之一,环鸟苷酸-腺苷酸合成酶(cGAS)通过识别细胞质的DNA分子,催化生成第二信使cGAMP(cyclic GMP-AMP)与干扰素基因刺激因子(STING)结合,诱导产生I型干扰素(IFN-I),激活机体先天免疫系统。cGAS-STING通路的适当激活有助于机体实现自我保护,因此,近年来STING激动剂在肿瘤免疫治疗的研究中引起了广泛关注,一些候选药物已进入临床研究,用于多种肿瘤治疗。与此同时,cGAS-STING通路异常激活会导致自身免疫性疾病的发生,获得了药物研究者的广泛关注并积极开发其抑制剂。该文总结了cGAS-STING通路的机制和调控位点,概述了cGAS-STING通路相关的免疫和炎症疾病及其抑制剂的研究进展。

Pathway for interferon-gamma to promote the differentiation of cholinergic neurons in rat embryonic basal forebrain/septal nuclei

BACKGROUND： The supernatant of interferon-gamma （IFNγ） co-cultured with neonatal rat cortical glia can promote the cells in embryonic basal forebrain/septal nuclei to differentiate into cholinergic neurons, but the mechanism is still unclear. OBJECTIVE： To analyze the pathways for IFNγ to promote the differentiation of primarily cultured cholinergic neurons in rat embryonic basal forebrain/septal nuclei through culture in different conditioned medium. DESIGN： A controlled experiment taking cells as the observational target. SETTINGS： Department of Biochemistry and Molecular Biology, Youjiang Medical College for Nationalities; Department of Cell Biology, Beijing University Health Science Center. MATERIALS： Sixty-four pregnant Wistar rats for 16 days （250-350 g） and 84 Wistar rats （either male or female, 5-7 g） of 0-1 day after birth were provided by the experimental animal department of Beijing University Health Science Center. Rat IFNγ were provided by Gibco Company; Glial fibrillary acidic protein by Huamei Company. METHODS： The experiments were carried out in the Department of Cell Biology, Beijing University Health Science Center and Daheng Image Company of Chinese Academy of Science from July 1995 to December 2002. ① Interventions： The nerve cells in the basal forebrain/septal nuclei of the pregnant Wistar rats for 16 days were primarily cultured, and then divided into four groups： Blank control group （not any supernatant and medium was added）; Control group （added by mixed glial cell or astrocyte conditioned medium）; IFNγ group （added by mixed glial cell or astrocyte conditioned medium＋IFNγ）. Antibody group （added by mixed glial cell or astrocyte conditioned medium＋IFNγ＋Ab-IFNγ）. Mixed glial cell or astrocyte conditioned medium was prepared using cerebral cortex of Wistar rats of 0-1 day after birth. ② Evaluation： The immunohistochemical method was used to perform the choline acetyltransferase （ChAT） staining of cholinergic neurons. The ChAT positive cells were counted. MAIN OUTCOME MEASURES： Comparison of ChAT positive cells in rat basal forebrain and septal nuclei in different conditioned medium. RESULTS： ① ChAT positive cells in mixed glial cell conditioned medium： The ChAT positive cells in the IFNγ group and antibody group were significantly more than those in the control group （P 〈 0.01）. ② ChAT positive cells in astrocyte conditioned medium： The ChAT positive cells in the IFNγ group were significantly more than those in the control group, but there was no significant difference between the antibody group and control group （P 〉 0.05）. CONCLUSION： IFNγ cannot directly promote the differentiation of cholinergic neurons, but plays a role through activating glial cells （except astrocytes） to produce IFNγ like molecules.

Cytokine gene expression in human hepatocytes infected with dengue virus serotype 3 (strain-16562)

Liver is a site of viral replication and liver dysfunction is a characteristic of severe dengue infection. To understand these mechanisms, we analyzed the response of a hepatic cell linage, HepG2 to infection with dengue 3 virus (strain 16562). Steady state levels of mRNA accumulation were assessed for 14 genes involved in modulation of the host immune responses, at 6, 24 and 48 hpi, by quantitative reverse transcription real-time PCR (qRT-PCR). Fourteen genes showed altered expression upon infection with D3V including;cytokines/chemokines (IL-1β, IL-6, IL-8, RANTES, MCP-2, IL-2Rα and TGF-βIIIR), type I interferon (IFN-α and IFN-β), and pattern-recognition receptors (TLR3, TLR8, RIG-1, MDA5 and MyD88). Although these genes are associated with mechanism of innate immune response and anti-viral activity, their altered expression does not inhibit D3V (strain 16562) growth kinetics and virus yield in HepG2 cells. Gene expression in liver may explain pathological changes associated with dengue virus infection.

Involvement of Dectin-2 in the Innate Inflammatory Response Triggered by Influenza Virus Hemagglutinin

C-type lectin receptors (CLRs) are representative pattern recognition receptors that recognize microbial polysaccharides expressed on antigen-presenting cells. In the present study, we carried out further detailed analysis on the involvement of Dectin-2, a CLR that senses high mannose polysaccharide, in innate immune responses induced by influenza virus hemagglutinin (HA). Treatment of HA with periodate or PNGase F induced lower interleukin (IL)-12p40 secretion by conventional dendritic cells (DCs) compared with the untreated group. In contrast, treatment with O-glycosidase did not affect cytokine production. Green fluorescent protein expression in canonical Dectin-2-transducing cells was approximately 3% - 12% following HA stimulation, except with the A/H1N1pdm09 subtype HA. This expression was markedly reduced in cells possessing mutated amino acids in the carbohydrate recognition domain of Dectin-2, especially following stimulation with HA derived from the A/H3N2 subtype. Interferon (IFN)-α production from CD11c+Siglec-H+PDCA-1+ plasmacytoid DCs was significantly increased in Dectin-2 knockout mice compared with wild-type mice upon stimulation with HA except for the B/Yamagata lineage HA. These results suggested that Dectin-2 is involved in initiating inflammatory responses via mannose polysaccharide on HA. However, other mechanisms may function in the antiviral response, including the type I IFN axis.