参苓白术散对感染鼠伤寒沙门菌小鼠的免疫调节作用

目的探讨参苓白术散对感染鼠伤寒沙门菌小鼠的抑菌作用及免疫调节机制。方法用鼠伤寒沙门菌标准菌株(STM,50115)制备STM小鼠模型,造模后给予小鼠参苓白术散(1 g/ml)或庆大霉素(2 mg/ml)连续灌胃10 d,观察小鼠盲肠病理改变,检测盲肠中TNF-α、IL-1β、IL-6、TLR4、MyD88、NF-κB mRNA水平及TLR4、MyD88、NF-κB蛋白含量,测定淋巴结中CD4~+T、CD8~+T及CD4~+IFN-γ和CD8~+IFN-γ细胞比例。结果与对照组比较,STM模型组TNF-α、IL-1β、IL-6及TLR4、MyD88、NF-κB mRNA水平升高(P0.01),参苓白术散组和庆大霉素组较比STM模型组呈下降趋势(P0.05);STM模型组TLR4、MyD88、NF-κB蛋白含量高于对照组(P0.01),参苓白术散组和庆大霉素组低于STM模型组(P0.05);STM模型组CD4~+T、CD8~+T及CD4~+IFN-γ和CD8~+IFN-γ细胞比例均高于对照组(P0.05),参苓白术散组高于STM模型组(P0.05),庆大霉素组较STM模型组有下降趋势(P0.05)。结论参苓白术散对STM感染具有一定治疗效果,治疗机制可能与下调TLR4-MyD88-NF-κB信号诱导的炎性细胞因子分泌及上调CD4~+T、CD8~+T比例及功能有关。     

TLR4/MyD88/NF-κB通路在真菌性角膜炎中的表达和作用

目的 探究Toll样受体4(TLR4)/髓样分化因子88(MyD88)/核因子κB(NF-κB)通路在真菌性角膜炎中的表达和作用。方法 选择2016年1月-2021年1月滕州市中心人民医院收治的82例(82眼)真菌性角膜炎角膜上皮组织为真菌组,另选择40例(40眼)健康角膜组织为正常组,采用免疫组化、实时荧光定量PCR(RT-PCR)和免疫印迹法检测角膜上皮中TLR4、MyD88和NF-κB蛋白表达阳性率、 mRNA及蛋白水平,酶联免疫吸附实验检测炎性细胞因子白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、γ-干扰素(IFN-γ)、α-干扰素(IFN-α)水平。结果 真菌性角膜炎角膜上皮中TLR4、MyD88和NF-κB蛋白阳性表达率、mRNA及蛋白表达水平高于正常角膜上皮(P<0.05);真菌性角膜炎角膜上皮中炎性细胞因子IL-1β、TNF-α、IFN-γ、IFN-α水平高于正常角膜上皮(P<0.05);真菌性角膜炎角膜上皮中TLR4、MyD88、NF-κB mRNA及蛋白表达水平与炎性细胞因子IL-1β、TNF-α、IFN-γ、IFN-α均呈正相关(P&...     

不同剂量流感病毒感染小鼠模型免疫应答的比较性研究

目的 比较不同剂量流感病毒感染小鼠后肺组织急性损伤情况,初步探讨感染剂量与机体抗病毒的固有、适应性免疫应答的关系。方法 用流感病毒A/PR/8/34（PR8;H1N1）构建小鼠感染102 PFU和103 PFU剂量模型,HE法检测肺组织损伤情况,HA法和免疫荧光染色法检测肺组织病毒滴度和感染程度,RT - PCR法检测肺组织炎性因子干扰素α（interferon - α, IFN - α）、干扰素β（interferon - α, IFN - β）、白细胞介素1β（interleukin - 1β, IL - 1β）、白细胞介素6（interleukin - 6, IL - 6）、肿瘤坏死因子α（tumor necrosis factor - α, TNF - α）及Toll样受体7（Toll - like receptor - 7, TLR7）、髓样分化因子88（myeloid differentiation primary response gene 88, MyD88）、肿瘤坏死因子受体相关蛋白6（TNF receptor associated factor 6, TRAF6）和核因子κB（nuclear factor κB, NF - κB）mRNA水平,免疫组化法对肺组织TLR7、MyD88、TRAF6和NF - κB蛋白定位。流式细胞术检测肺组织、支气管肺泡灌洗液（bronchoalveolar lavage fluid, BALF）和淋巴结中CD4+、CD8+T细胞比例。结果 与102 PFU组比较,103 PFU组小鼠肺组织病毒滴度显著升高（t = 3.071,P = 0.008）,炎症因子IFN - α、IFN - β、IL - 1β、IL - 6、TNF - α mRNA水平上升（t = 4.816,P = 0.003;t = 4.104,P = 0.006;t = 3.992,P = 0.007;t = 4.049,P = 0.007;t = 3.737,P = 0.009）,TLR7、MyD88、TRAF6和NF - κB mRNA水平有不同程度的升高（t = 2.905,P = 0.027;t = 3.854,P = 0.008;t = 3.760,P = 0.009;t = 4.312,P = 0.005）及蛋白表达显著增加（t = 4.712,P = 0.003;t = 4.008,P = 0.007;t = 4.398,P = 0.005;t = 4.564,P = 0.004）,BALF、肺组织和淋巴结中CD4+T细胞比例呈上升趋势（t = 3.771,P = 0.009;t = 2.463,P = 0.049;t = 3.386,P = 0.015）,BALF和肺组织CD8+T细胞比例上调（t = 5.297,P = 0.002;t = 3.502,P = 0.013）。结论 病毒载量影响机体固有和适应性免疫应答状态,通过上调 TLR7 - MyD88 - TRAF6 - NF - κB信号通路促进下游炎症反应,并启动CD4+T和CD8+T细胞发挥抗病毒效应。     

儿童难治性支原体肺炎外周血TLR2信号通路表达及其对疗效的诊断价值

目的 探究难治性支原体肺炎(RMPP)患儿Toll样受体2(TLR2)信号通路表达及其对疗效的诊断价值。方法 选取2019年5月-2021年5月济南市妇幼保健院收治的70例RMPP患儿为RMPP组，另选取医院同期收治的70例普通支原体肺炎(MPP)患儿为MPP组。收集两组患儿的临床资料，采用实时荧光定量聚合酶链式反应(qRT-PCR)检测外周血单个核细胞(PBMC)TLR2 mRNA、髓样分化蛋白88(MyD88)mRNA、核转录因子-κB(NF-κB)mRNA相对表达水平，酶联免疫吸附法检测血清肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、IL-8、干扰素-γ(IFN-γ)、半胱氨酰白三烯(CysLTs)水平，采用受试者工作特征(ROC)曲线分析TLR2 mRNA、MyD88 mRNA、NF-κB mRNA相对表达水平对RMPP的诊断价值。根据RMPP患儿治疗后疗效将患儿分为有效组和无效组，比较治疗后7 d时TLR2 mRNA、MyD88 mRNA、NF-κB mRNA相对表达水平，并分析其表达与治疗效果的关系。结果 RMPP组的TLR2 mRNA、MyD88 mRNA...     

鱼腥草提取物对肺炎支原体感染大鼠的抗炎作用及其作用机制

目的 对肺炎支原体感染大鼠进行鱼腥草提取物治疗,对其所产生抗炎功效及作用机制进行分析。方法 SPF级Wistar雄性大鼠分为空白组、肺炎支原体感染模型组、鱼腥草提取物低剂量组和高剂量组各9只。空白组、模型组只进行生理盐水灌胃,低剂量组和高剂量组给予鱼腥草提取物125 mg/kg、500 mg/kg灌胃,持续7 d后检测外周血转化生长因子-β(TGF-β)、涎液化糖链抗原-6(KL-6)、表面活性蛋白D(SP-D)、炎症因子及Toll样受体4(TLR4)、髓样分化因子88(MyD88)、核因子κB(NF-κB)mRNA相对表达量,免疫印迹法检测肺组织中TLR4、MyD88、NF-κB蛋白表达。结果 与空白组比较,模型组、鱼腥草提取物低剂量组、高剂量组TGF-β、KL-6、SP-D、IL-13、TNF-α水平、TLR4、MyD88、NF-κB mRNA表达量、TLR4、MyD88、NF-κB蛋白表达量均升高,IL-12水平降低(P<0.05);与模型组、低剂量组比较,高剂量组TGF-β、KL-6、SP-D、IL-13、TNF-α水平、TLR4、MyD88、NF-κB mRNA表达量、...     

TLR4/MyD88/NF-κB信号通路在萎缩性胃炎伴幽门螺杆菌感染中的作用

目的 探讨Toll样受体4(TLR4)/髓样分化因子88(MyD88)/核因子κB(NF-κB)信号通路在萎缩性胃炎伴幽门螺杆菌感染中的作用及临床意义。方法 选取2019年6月-2021年5月在徐州市中心医院消化内科接受治疗的118例萎缩性胃炎伴幽门螺杆菌感染患者作为胃炎组,根据慢性胃炎的内镜分型分级标准中的萎缩性胃炎分类标准分为Ⅰ级、Ⅱ级、Ⅲ级,同时选择40名健康人作为对照组。酶联免疫吸附法检测两组血清中TLR4、MyD88、NF-κB以及白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)炎性因子的表达水平。应用受试者工作特征曲线(ROC曲线)分析TLR4、MyD88和NF-κB对萎缩性胃炎伴幽门螺杆菌感染的预测价值。结果 与对照组比较,研究组患者TLR4、MyD88及NF-κB的表达量均增高(P<0.05);炎性因子IL-1β、IL-6、TNF-α的表达水平高于对照组(P<0.05);血清TLR4、MyD88和NF-κB联合预测萎缩性胃炎伴幽门螺杆菌感染的AUC为0.897,高于单独检测的0.854、0.858、0.870。结论 血清中TLR4、MyD88、NF...     

重型颅脑损伤患者术后颅内感染病原菌及脑脊液单核细胞TLR4 mRNA与MyD88 mRNA水平

目的 分析重型颅脑损伤(STBI)患者术后颅内感染病原菌及脑脊液单核细胞中Toll样受体4(TLR4)mRNA和髓系分化因子88(MyD88)mRNA。方法 选择2019年3月-2021年9月青岛市中医医院收治的STBI患者121例，术后颅内感染患者为感染组47例，未发生颅内感染患者为无感染组74例，分析感染组患者病原菌特点。依据神经功能缺损评分(NIHSS)将感染组患者分为轻度组8例、中度组20例、重度组19例，比较不同分组患者脑脊液单核细胞TLR4和MyD88表达，及感染相关指标肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)、免疫球蛋白G(IgG)水平。结果 STBI患者术后颅内感染共培养分离病原菌47株，其中革兰阳性菌28株占59.57%,以凝固酶阴性葡萄球菌和金黄色葡萄球菌为主；革兰阴性菌19株占40.43%,以鲍氏不动杆菌和铜绿假单胞菌为主；感染组NIHSS评分、脑脊液单核细胞TLR4 mRNA和MyD88 mRNA表达量、血清TNF-α、IFN-γ均高于无感染组，血清IgG低于无感染组(P<0.05);重度组患者脑脊液单核细胞TLR4 mRNA和MyD88 ...     

肠梗阻并发腹腔感染患者TLR4/NF-κB信号通路及其与病情转归的关系

目的 探究肠梗阻并发腹腔感染(IAI)患者外周血Toll样受体4(TLR4)/核因子κB(NF-κB)信号通路及其与病情转归的关系。方法 分别选取2018年1月-2021年6月大连大学附属中山医院肠梗阻并发IAI患者117例(感染组)和肠梗阻未合并感染患者109例(未感染组),检测外周血单个核细胞(PBMC)中TLR4 mRNA、髓样分化因子88(MyD88)mRNA和NF-κB mRNA水平及白细胞介素-4(IL-4)、IL-10和肿瘤坏死因子-α(TNF-α),同时采集基本资料并完善其他检查,根据感染程度和抗感染疗效对患者进行分组,并比较不同程度和疗效患者各项指标差异。结果 感染组PBMC中TLR4 mRNA、MyD88 mRNA和NF-κB mRNA及IL-4、IL-10与TNF-α高于未感染组(P<0.05);重度组PBMC中TLR4、MyD88和NF-κB mRNA和IL-4、IL-10及TNF-α水平高于轻中度组(P<0.05);好转组治疗3 d时PBMC中TLR4、MyD88和NF-κB mRNA及IL-4、IL-10和TNF-α均降低(P<0.05),...     

删除CD4~+CD25~+T细胞对OVA诱导的小鼠体液免疫应答的影响

目的观察删除CD4+CD25+T细胞对OVA免疫小鼠体液免疫应答的影响。方法小鼠腹腔注射抗CD25单克隆抗体,分别于3天、10天、27天采血流式检测外周血中CD4+CD25+T细胞的比例;注射抗CD25单克隆抗体3天后,OVA加铝佐剂免疫未删除和删除CD4+CD25+T细胞小鼠,7天后加强免疫一次,分别于初次免疫后7天,加强免疫后14天采血制备血清,ELISA法检测血清中OVA特异性IgE和IgG1的浓度。结果注射抗CD25单克隆抗体3天和10天,外周血中无CD4+CD25+T细胞;27天后CD4+CD25+T细胞的比例部分恢复。初次免疫7天后,删除CD4+CD25+T细胞小鼠总IgE、OVA特异性IgE和IgG1浓度较未删除组升高;加强免疫14天后,删除CD4+CD25+T细胞小鼠OVA特异性IgE较未删除组升高。结论删除CD4+CD25+T细胞能够影响小鼠OVA特异性体液免疫应答。     

芩百清肺浓缩丸治疗肺炎支原体感染大鼠模型细胞因子表达水平变化

目的分析芩百清肺浓缩丸治疗肺炎支原体(MP)感染大鼠细胞因子表达水平变化,进一步探究芩百清肺浓缩丸对其免疫机制及炎症反应的调控。方法 SPF级成年雄性Wistar大鼠(90~110 g)60只随机分为4组:正常对照组、肺炎支原体肺炎模型(MP组)、芩百清肺浓缩丸组及阿奇霉素组。通过经鼻反复感染MP构建感染模型,对照组鼻内滴入等体积支原体改良培养基。芩百清肺浓缩丸组及阿奇霉素组从MP感染日起连续4天分别给与芩百清肺浓缩丸3.2 g/kg及阿奇霉素25 mg/kg,每日1次,模型组给予等量生理盐水灌胃。给药后第5天抽取血样、分离血清检测各组大鼠血清中肿瘤坏死因子-α(TNF-α)及γ干扰素(IFN-γ)水平,留取大鼠肺组织检测Toll样受体4(TLR4)、髓样分化因子88(MyD88)、核转录因子-κB(NF-κB)蛋白表达水平。结果与对照组比较,MP组、芩百清肺浓缩丸组及阿奇霉素组大鼠血清中TNF-α含量显著升高(均P<0.05),与MP组比较,芩百清肺浓缩丸组及阿奇霉素组TNF-α水平显著降低(均P<0.05),但芩百清肺浓缩丸组与阿奇霉素组TNF-α水平无显著性差异;与对照组比较,MP组、芩百清肺浓缩丸组及阿奇霉素组IFN-γ含量均呈不同程度的降低(均P<0.05),与MP组比较,芩百清肺浓缩丸组及阿奇霉素组的IFN-γ水平均升高(均P<0.05),但芩百清肺浓缩丸组与阿奇霉素组IFN-γ水平无显著性差异;肺组织实时荧光PCR(qPCR)结果显示,与对照组比较,MP组、芩百清肺浓缩丸组及阿奇霉素组的TLR4、MyD88、 NF-κB mRNA表达水平均呈不同程度的升高(均P<0.05),与MP组比较,芩百清肺浓缩丸组和阿奇霉素组上述指标水平显著降低(均P<0.05),但芩百清肺浓缩丸组和阿奇霉素组上述指标水平无显著性差异。免疫印迹(WB)结果示TLR4、MyD88、 NF-κB的蛋白表达变化趋势与mRNA一致。结论芩百清肺浓缩丸可降低MP感染大鼠TLR4、MyD88、NF-κB、TNF-α的表达水平,增加IFN-γ的水平,从而减轻MP肺炎的炎症反应。     

TLR4 and MyD88 control protection and pulmonary granulocytic recruitment in a murine intranasal RSV immunization and challenge model

An intranasal vaccine composed of Toll-like receptor 2 (TLR2) ligand Neisseria meningitidis outer membrane proteins and Toll-like receptor 4 (TLR4) ligand Shigella flexneri lipopolysaccharide (LPS) (Protollin) and enriched respiratory syncytial virus (RSV) proteins (eRSV) has been demonstrated to promote balanced Th1/Th2 responses without eosinophil recruitment and to protect against challenge in mouse models. We used TLR2, TLR4 and myeloid differentiation factor 88 (MyD88) knock-out (-/-) mice to investigate the roles of these signalling pathways on immunogenicity, protection and pulmonary infiltrates following RSV immunization and challenge. Antigen-specific systemic and mucosal antibody production was significantly impaired only in TLR4-/- mice following Protollin–eRSV immunization. In contrast, an intact MyD88 pathway was crucial to elicit a balanced type 1:type 2 immune response, characterized by increased splenocyte production of antigen-induced IFNγ and IL-10 with concomitant reduction of IL5, IgG2a isotype switching and abrogation of pulmonary eosinophil recruitment following challenge. MyD88-dependent signalling also contributed to neutrophil recruitment to the lungs following immunization with eRSV antigen, in the presence or absence of Protollin, compared to a mock antigen or vaccine. Both TLR4 and MyD88-signalling were required for optimal protection against challenge. The upregulation of early signalling molecules IFN-β, TNFα, CD40 and CD86 were studied in splenocytes isolated from naïve TLR2, TLR4 and MyD88-/- mice following stimulation with vaccine components. Splenocytes from TLR4-/- mice displayed reduced IFN-β while those of MyD88-/- mice elicited less TNFα and lower expression of CD40 and CD86 on CD11c+ cells. Together, our results suggest that optimal immunogenicity and protection against RSV without risk of enhanced pulmonary inflammation requires intact TLR4/MyD88-dependent signalling.     

脂多糖经MyD88/NF-κB信号途径抑制Bewo细胞中乙型肝炎病毒复制

目的 探讨Toll样受体4(TLR4)配体脂多糖(LPS)抑制人滋养层细胞Bewo中乙型肝炎病毒( HBV)复制的作用机制,为防治HBV宫内感染提供依据.方法 首先将2μg 1.3倍HBV全基因重组质粒pcDNA3.1(+)-HBV1.3转染Bewo细胞12h后,以TLR4配体LPS处理3d.尔后用LPS处理Bewo细胞,观察IFN-β、TNF-α表达的动力学、NF-κB拮抗剂二硫代氨基甲酸吡咯烷( PDTC)对LPS诱导Bewo细胞产生细胞因子的作用.采用微粒子酶免疫分析法(MEIA)和荧光定量PCR法分别检测HBsAg、HBeAg和HBV DNA水平,并以ELISA和RT-PCR分别检测IFN-β、TNF-α水平及TIR结构域的转接蛋白(TRIF)、髓样分化蛋白(MyD88)表达.结果 与对照组比较,LPS可显著抑制Bewo细胞中HBV复制(P＜0.01),且LPS可显著诱导Bewo细胞产生TNF-α(P＜0.05),呈时间和剂量依赖性.PDTC可抑制LPS诱导细胞产生TNF-α,显著低于对照组(P＜0.01),但对IFN-β无显著作用(P＞0.05).与对照组比较,LPS可诱导HBV重组质粒转染的Bewo细胞表达MyD88(P＜0.01).结论 通过MyD88/NF-κB信号途径诱导Bewo细胞产生TNF-α,TLR4配体LPS可显著抑制HBV复制.     

A combined carrier-adjuvant system of peptide nanofibers and toll-like receptor agonists potentiates robust CD8+ T cell responses

Improving CD8+ T cell responses activated by subunit vaccination is crucial for improving vaccine efficacy and safety. Here we report a carrier-adjuvant system composed of self-assembling peptide nanofibers presenting an immunodominant antigen from herpes simplex virus (HSV) and toll-like receptor (TLR) agonists that induces robust effector and memory CD8+ T cell responses in mice. The effector function of vaccine-induced CD8+ T cells was influenced by the type of TLR agonist. The use of CpG (TLR9 agonist) resulted in significantly greater specific in vivo cytotoxicity and trended towards more cells producing both IFN-γ and TNF-α compared to gardiquimod (TLR7 agonist). Prime-boost immunization with peptide nanofibers combined with either adjuvant resulted in development of HSV-specific CD8+ memory T cells further demonstrating the capability of the carrier-adjuvant system to induce strong HSV-specific CD8+ T cell responses. Inclusion of peptide epitope-nanofibers in protein-based subunit vaccines should increase the functional spectrum of the vaccine-elicited immune response and protection.     

脂多糖经MyD88／NF-KB信号途径抑制Bewo细胞中乙型肝炎病毒复制

目的探讨Toll样受体4（TLR4）配体脂多糖（LPS）抑制人滋养层细胞Bewo中乙型肝炎病毒（rtBv）复制的作用机制,为防治HBV宫内感染提供依据。方法首先将2txg1．3倍HBV全基因重组质粒pcDNA3．1（＋）-HBV1．3转染Bewo细胞12h后,以TLR4配体LPS处理3d。尔后用LPS处理Bewo细胞,观察IFN—β、TNF-a表达的动力学、NF—KB拮抗剂二硫代氨基甲酸吡咯烷（PDTC）对LPS诱导Bewo细胞产生细胞因子的作用。采用微粒子酶免疫分析法（MEIA）和荧光定量PCR法分别检测HBsAg、HBeAg和HBVDNA水平,并以ELISA和RT—PCR分别检测IFN-β、TNF—a水平及TIR结构域的转接蛋白（TRIF）、髓样分化蛋白（MyD88）表达。结果与对照组比较,LPS可显著抑制Bewo细胞中HBV复制（P〈0．01）,且LPS可显著诱导Bewo细胞产生TNF-a（P〈0．05）,呈时间和剂量依赖性。PDTC可抑制LPS诱导细胞产生TNF-a,显著低于对照组（P〈0．01）,但对IFN—β无显著作用（P〉0．05）。与对照组比较,LPS可诱导HBV重组质粒转染的Bewo细胞表达MyD88（P〈0．01）。结论通过MyD88／NF—KB信号途径诱导Bewo细胞产生TNF—a,TLR4配体LPS可显著抑制HBV复制。     

Flagellin enhances tumor-specific CD8 T cell immune responses through TLR5 stimulation in a therapeutic cancer vaccine model

Tumor antigen (TA)-specific immunotherapy is an emerging approach for cancer treatment. Potent adjuvants are prerequisites to the immunotherapy for overcoming the low immunogenicity of TAs. We previously demonstrated that a bacterial flagellin, Vibrio vulnificus FlaB, has potent adjuvant activity in various vaccination models. In this study, we investigated whether the FlaB protein could be a potent adjuvant for a human papillomavirus 16 E6 and E7 (E6/E7) peptide-based anticancer immunotherapy. We used an E6/E7-expressing TC-1 carcinoma implantation animal model and tested TA-specific immunomodulation by FlaB. We co-administered the E6/E7 peptide either with or without FlaB into TC-1 tumor-bearing mice and then analyzed the antitumor activity of the peptide. FlaB significantly potentiated specific antitumor immune responses elicited by the peptide immunization, as evidenced by retarded in vivo tumor growth and significantly prolonged survival. We noticed that TC-1 cells do not express Toll-like receptor 5 (TLR5) on their surface and the TLR5 signaling pathway in TC-1 cells was not responsible for the antitumor effect of FlaB. FlaB potentiated the CTL activity and Ag-specific IFN-γ production of CD8⁺ T cells from the draining lymph node and spleen. In addition, this antitumor activity was abrogated following the in vivo depletion of CD8⁺ T cells and in TLR5 knockout (KO) or MyD88 KO mice. These results suggest that flagellin could enhance TA-specific CD8⁺ CTL immune responses through TLR5 stimulation in cancer immunotherapy.     

Priming of CD8+ T-cell responses after DNA immunization is impaired in TLR9- and MyD88-deficient mice

The plasmid DNA vaccine not only provides expression of the antigen in vivo, but also activates cells of the innate immune system via unmethylated CpG-containing DNA sequences that are recognized by Toll like receptor 9 (TLR9). The requirement of such immunostimulatory activity for induction of CD8+ T-cell responses after DNA immunization is still controversial. In the present study we assessed induction of CD8+ T-cell responses against an immunodominant H-2D(b)-restricted epitope of human prostate-specific antigen in C57Bl/6 (wild-type), TLR9- and MyD88-deficient mice. A single DNA immunization resulted in efficient priming of CD8+ T responses in wild-type mice but not in TLR9- or MyD88-deficient mice. However, priming of CD8+ T cell responses was observed in TLR9-deficient but not in MyD88-deficient mice after multiple DNA immunizations. Moreover, induction of CD8+ T cell responses in TLR9-deficient mice was dependent on the presence of endotoxin contamination in plasmid DNA preparations. Collectively, these results demonstrate that TLR9-dependent immunostimulatory activity of plasmid DNA is essential for priming of CD8+ T-cell responses and that other bacterial compounds present in plasmid DNA preparations and acting via MyD88-dependent pathway could provide alternative signals necessary for priming of CD8+ T cells.     

MyD88-dependent protective immunity elicited by adenovirus 5 expressing the surface antigen 1 from Toxoplasma gondii is mediated by CD8(+) T lymphocytes

Toxoplasma gondii is an intracellular parasite widely spread around the world. The surface antigens (SAG) 1, 2 and 3 are the main proteins expressed on the surface of T. gondii tachyzoites. Replication-defective adenovirus serotype 5 (rAd5) is one of the most potent recombinant viral vectors for eliciting T cell-mediated immunity in mice and humans. Here we show that vaccination with rAd5 expressing SAG1 (AdSAG1), but neither SAG2 nor SAG3, induces protective immunity in the highly susceptible C57BL/6 mice challenged with T. gondii. Furthermore, we evaluated different immunological components involved on viral induced protective immunity. We observed that host protection elicited by AdSAG1 is highly dependent on IL-12, IFN-γ and CD8⁺ T lymphocytes. Importantly, the induction of protective immunity (T cell-derived IFN-γ) was also dependent on Myeloid Differentiation Factor 88 (MyD88), and thus, likely to involve Toll-like Receptors. We conclude that protective parasite specific-CD8⁺ T cells are elicited by a mechanism that involves MyD88-dependent induction of IL-12.     

Phenotypic and functional maturation of dendritic cells induced by polysaccharide isolated from Paecilomyces cicadae

Paecilomyces cicadae Miquel Samson is the anamorph of Cordyceps cicadae Shing and is used in functional foods for the prevention and treatment of various diseases. In the present study, we examined the effects of P. cicadae polysaccharide (PCP) on dendritic cell (DC) maturation. Phenotypic maturation of DCs by PCP was confirmed by the elevated expressions of CD80, CD86, major histocompatibility complex (MHC)-I, and MHC-II molecules and functional maturation by increased expression of interleukin-12, interleukin-1β, and tumor necrosis factor-α, enhanced allogenic T cell stimulation, and decreased endocytosis. PCP induced the maturation of DCs from C3H/HeN and C57BL/6 mice but not from Toll-like receptor (tlr) 4?/? knockout mice and TLR4-mutated C3H/HeJ mice, which suggests that TLR4 is the membrane receptor for PCP. PCP increased the degradation of inhibitor of nuclear factor-κB (NF-κB) α/β, which enhanced the nuclear translocation of NF-κB p50/p65 and induced the phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinases, which are signaling molecules downstream of TLR4. These results indicate that PCP induces DC maturation through TLR4 signaling.