Nerve growth factor promotes expression of costimulatory molecules and release of cytokines in dendritic cells involved in Th2 response through LPS-induced p75NTR

Introduction: Nerve growth factor (NGF) plays an important role in asthmatic inflammatory responses. However, the effects of NGF on dendritic cells (DCs) in asthmatic inflammation remain unknown. Therefore, we examined the effects of NGF on co-stimulatory molecules and the release of cytokines after ovalbumin (OVA) and a low dose of LPS (low LPS) stimulation of dendritic cells. Methods: Bone-marrow-derived dendritic cells (BMDCs) were collected from 6- to 8-week-old wide or TLR4^?/? mice. BMDCs were treated with OVA and/or low LPS for 12h, and then stimulated with NGF for 24h. ELISA and flow cytometry were performed to measure TSLP, IL-6, IL-10, and IL-12 production and MHCII and CD86 expression on BMDCs. BMDCs were exposed to p75 neurotrophin receptor (p75NTR) inhibitor (TAT-Pep5) or NF-kB inhibitor (QNZ) 30 min prior to NGF 1 h after NGF intervention, the levels of RelA and RelB in cytoplasmic and nuclear were detected by west blot. Co-cultured BMDCs with naïve CD4⁺ T cells, and ELISA was used to detect IL-4 and INF-γ levels. Results: NGF was found to markedly promote OVA and low LPS-induced expression of MHCII, CD86, secretion of TSLP and IL-6, and Th2-response-stimulating capacity of BMDCs. NGF affected BMDCs through LPS-induced p75NTR expression. TAT-Pep5 or QNZ could attenuate the promotive effect of NGF. Conclusions: NGF facilitates OVA with lowLPS-induced maturation of mouse BMDCs through LPS-up-regulated p75 NTR via activation of NF-κB pathways, providing another mechanism for the involvement of NGF in the Th2 response.     

呼吸道合胞病毒感染促进哮喘小鼠气道分泌TSLP和Th2炎症反应

目的 探讨呼吸道合胞病毒(RSV)对哮喘小鼠胸腺基质淋巴细胞生成素(TSLP)分泌的影响,以探索RSV对哮喘小鼠Th1/Th2免疫反应的调节作用.方法 雌性BALB/c小鼠32只.随机分成4组,分别为磷酸盐缓冲液(PBS)对照组、鸡卵白蛋白(OVA)组、RSV组、OVA/RSV组;应用OVA腹腔注射致敏、OVA气道雾化结合RSV滴鼻激发哮喘;无创肺功能检测小鼠气道反应性,ELISA法检测小鼠血清IL-4、IFN-γ、IL-5、IL-13水平;ELISA法检测气管灌洗液(BALF)TSLP含量并进行细胞分类计数;小鼠肺组织病理观察炎症反应,免疫组化观察小鼠气管上皮细胞TSLP表达水平.结果 RSV感染促进哮喘小鼠呼吸道分泌TSLP增加,OVA/RSV组小鼠TSLP浓度达(2.13±0.05)ng/ml,高于其他组(P<0.01);同时促进IL-4、IL-5、IL-13等Th2型细胞因子的分泌,并增加IFN-γ分泌;0VA/RSV组BALF细胞总数、嗜酸性粒细胞数、中性粒细胞数、淋巴细胞数与其他各组比较均明显增加;无创肺功能检测显示OVA/RSV组小鼠气道反应性明显增高,乙酰甲胆碱浓度达6.25 mg/ml时,Penh值(318.66±50.87)明显增加,与其他各组比较具有统计学意义(P<0.01);病理观察显示RSV感染明显加重哮喘小鼠气道炎症细胞浸润;免疫组化染色证实RSV/OVA组小鼠气道上皮细胞TSLP表达量较高.结论 RSV感染可以增加小鼠气道上皮细胞表达TSLP,促进Th2细胞因子的表达,加重哮喘小鼠肺部Th2炎症反应.     

沙丁胺醇与色甘酸钠对大鼠腹腔肥大细胞脱颗粒过程中磷脂酶D活性的影响

采用主动致敏的大鼠腹腔肥大细胞 (RPMC)为实验材料 ,细胞脱颗粒以 β 氨基己糖苷酶释放率为指标 ,细胞磷脂酶D(PLD)活性采用酶联化学发光法检测 .结果发现 ,卵白蛋白 (4mg·L- 1)攻击主动致敏的RPMC 12 0s后 ,细胞PLD活性与β 氨基己糖苷酶释放率均明显增加 ,分别为对照组的 2倍及 8倍以上 .1%正丁醇 ,10mmol·L- 12 ,3 二磷酸甘油酸能显著抑制PLD活性 ,且使PLD活性及细胞 β 氨基己糖苷酶释放率均降低到对照水平 .Wortmannin ,30 0nmol·L- 1能显著抑制PLD活性 ,并减少细胞 β 氨基己糖苷酶释放 .1,10 μmol·L- 1的沙丁胺醇与色甘酸钠均能部分抑制PLD活性 ,并减少细胞 β 氨基己糖苷酶的释放 .结果表明 ,PLD在主动致敏的RPMC脱颗粒过程中起一定作用 ;沙丁胺醇 (1,10 μmol·L- 1) ,色甘酸钠 (1,10 μmol·L- 1)抑制主动致敏的RPMC脱颗粒的作用机理与抑制PLD有关 .     

miR-375在变应性鼻炎小鼠鼻黏膜上皮细胞凋亡中的调控作用

目的探讨miR-375在变应性鼻炎小鼠鼻黏膜上皮细胞凋亡和炎症反应中的调控作用。方法运用卵清蛋白(OVA)致敏的小鼠变应性鼻炎模型,使用实时定量PCR(qRT-PCR)、蛋白质印迹试验(Western Blot)、酶联免疫吸附试验(ELISA)、免疫组织化学检测鼻黏膜上皮细胞内miR-375、JAK2、细胞凋亡相关蛋白(JAK2蛋白,裂解的蛋白酶3(Cleaved caspase 3),聚[ADP-核糖]聚合酶裂解酶(Cleaved PARP),蛋白酶3(Caspase 3),聚[ADP-核糖]聚合酶(PARP),p-STAT3蛋白,STAT3蛋白和β肌动蛋白(β-actin))和血浆IL-6、TNF-α、IL-10的表达水平。结果miR-375在变应性鼻炎小鼠的鼻黏膜上皮细胞中表达降低,而JAK2表达增高;JAK2蛋白、p-STAT3蛋白和裂解的蛋白酶3均在OVA组表达增高;给OVA致敏的变应性鼻炎小鼠注射miR-375模拟物可以导致血清IL-6、TNF-α的分泌下降,而IL-10分泌增加,该作用可以被带有过表达JAK2的腺病毒感染后而减弱。结论miR-375/JAK2调控通路存在于变应性鼻炎鼻黏膜上皮细胞中,并通过JAK2/STAT3信号通路调控细胞的凋亡和炎症反应,miR-375在变应性鼻炎的病程中有保护性机制。     

重组E.coli. LLO/OVA明显增强小鼠CD11c细胞活性及抗肿瘤免疫

目的 探讨重组E.coli. LLO/OVA 诱导C57BL/6小鼠机体免疫的途径,观察其免疫后小鼠机体抑制B16-OVA黑色素瘤的效果.方法 磁珠分离E.coli. LLO/OVA及E.coli. OVA免疫后小鼠脾脏CD11c、CD4 和CD8 T细胞并检测CD11c细胞诱导同源CD4 和CD8 T增殖水平和细胞因子分泌程度;流式细胞检测小鼠脾脏内肿瘤抗原OVA257-264 SIINFEKL特异的细胞毒T细胞含量.比较两种E.coli. 免疫后,恶性黑色素瘤B16-OVA在小鼠肺内形成瘤结节的数量.结果 与E.coli. OVA相比, E.coli. LLO/OVA免疫后小鼠脾脏CD11c细胞诱导同源CD4 T细胞增殖作用增强、IL-2分泌增高;同时诱导CD8 T细胞增殖和IFN-γ分泌的作用也明显增强;OVA257-264 SIINFEKL特异的CD8 T细胞含量也明显增高;小鼠肺内形成B16-OVA瘤结节平均数明显减少. 结论 E.coli. LLO/OVA有效地诱导小鼠CD11c细胞活化,增强其对CD4 T细胞增殖和IL-2分泌以及对CD8 T细胞增殖、IFN-γ分泌的作用,诱导了更多的OVA特异的CD8 T细胞,使机体产生了更强的抗肿瘤免疫.     

Phosphorothioated antisense oligodeoxynucleotide suppressing interleukin-10 is a safe and potent vaccine adjuvant

While vaccination is highly effective for the prevention of many infectious diseases, the number of adjuvants licensed for human use is currently very limited. The aim of this study was to evaluate the safety, efficacy, and to clarify the mechanism of a phosphorothioated interleukin (IL)-10-targeted antisense oligonucleotide (ASO) as an immune adjuvant in intradermal vaccination. The cytotoxicity of IL-10 ASO and its ability to promote T cell proliferation were assessed by Cell Counting Kit-8 (CCK-8) assay. The contents of IL-6, IL-8, TNF-α, IL-1β, and IL-10 in inoculated local tissue and the antigen-specific antibody titers in mouse serum samples were determined by ELISA. The target cells of IL-10 ASO were observed using immunofluorescent staining. The results showed that the specific antibody titer of ovalbumin (OVA), a model antigen, was increased 100-fold upon addition of IL-10 ASO as an adjuvant compared to that of OVA alone. IL-10 ASO showed an immunopotentiation efficacy similar to that of Freund’s incomplete adjuvant, with no detectable cell or tissue toxicity. In vitro and in vivo experiments confirmed that IL-10 ASO enhances immune responses by temporarily suppressing IL-10 expression from local dendritic cells and consequently promoting T cell proliferation. In conclusion, IL-10 ASO significantly enhances immune responses against co-delivered vaccine antigens with high efficacy and low toxicity. It has the potential to be developed into a safe and efficient immune adjuvant.     

Organ-specific autoimmunity

The past year has seen advances in our understanding of the mechanisms that control the expression of organ-specific autoimmunity. Attempts to develop therapeutic strategies for the prevention of autoimmune disease have largely been based on deviation of the T-cell response away from an autoaggressive, pro-inflammatory Th1 response. Manipulation of the cytokine environment at the site of antigen uptake or presentation, the source of endogenous antigen, costimulatory molecules or peptides processed and presented has yielded interesting results.     

The expression of murine eutaneous late phase reaction requires both IgE antibodies and CD4 T eells

Background Exposure of atopic patients to a specific allergen evokes an immediate response which is followed, in many cases, by a late phase reaction (LPR) some hours later. Here we have examined the immunological mechanisms required for the expression of cutaneous LPR in mice. Methods BALB/c mice were immunized by i.p. injection of ovalbumin (OVA) and alum actively or by i.v. injection of anti-OVA IgE monoclonal antibody (mAb) passively. After challenge by intradermal injection of OVA into ears, the changes in ear thickness, the number of eosinophils, and the levels of IL4 and IFN-γ protein at the site of antigen challenge were examined. Results Actively immunized mice developed a biphasic response at the site of OVA injection, while mice passively immunized with IgE anti-OVA mAb displayed a strong early response but no LPR. Cell transfer experiments using BALB/c nu/nu mice revealed that both OVA-specific IgE mAb and OVA-primed CD4 T cells were required to evoke LPR. Moreover, LPR was associated with increased levels of IL-4 production concomitant with reduced IFN-γ production and was abolished by pretreatment with anti-IL-4 neutralizing mAb. Conclusion It is suggested that murine cutaneous LPR against OVA is a type 2 inflammatory response in which both IgH antibodies and CD4 T cells play an obligatory role.