重组腺病毒介导的sTLR2对LPS致炎小鼠抗炎效应的实验研究

目的:观察携带Toll样受体2(TLR2)胞外区基因的重组腺病毒介导的sTLR2在小鼠体内的抗炎作用,为急性炎症反应的防治提供新的思路和治疗策略。方法:建立亚致死剂量脂多糖(LPS)所致炎症小鼠模型。将BALB/c小鼠随机分为正常对照组、炎症对照组及重组腺病毒(Ad)TLR2实验组。AdTLR2于致炎前后,分别作用于小鼠,观察其对小鼠生存时间的影响,并应用ELISA对血清TNF-α、IL-1β、IL-6、IL-10和IL-13的含量进行检测,探讨AdTLR2对小鼠血清细胞因子水平变化的影响。结果:重组AdTLR2作用于炎症小鼠模型后,实验组小鼠的生存时间与炎症对照组比较相对延长,并且实验组中血清TNF-α、IL-1β、IL-6、IL-10和IL-13的水平均较炎症对照组显著降低(P0.05)。结论:重组AdTLR2能够使LPS所致炎症小鼠模型的生存时间相对延长,并能够降低炎症小鼠血清中TNF-α、IL-1β、IL-6、IL-10和IL-13的含量,提示AdTLR2在活体内可以分泌sTLR2蛋白发挥免疫调节作用并能降低血清中炎性细胞因子的水平,具有一定的抗炎作用。     

1人TLR4胞外区基因重组腺病毒载体的构建与鉴定

目的 构建并鉴定人TLR4胞外区基因重组腺病毒载体.方法 以pUCm-TLR4质粒为模板,运用PCR技术扩增TLR4胞外区目的 基因片段,片段回收后经酶切连接穿梭质粒pAdTrack-CMV上,获得重组腺病毒质粒pAdTrack-CMV-TLR4.通过Kpn Ⅰ和HindⅢ双酶切,测序鉴定后,将鉴定正确的质粒经PmeⅠ酶切线性化后,转化到含有腺病毒骨架质粒pAdEasy-1的感受态细菌BJ5183中,进行同源重组,卡那抗性筛选阳性克隆,提取质粒,用脂质体介导转染293细胞,通过观察绿色荧光蛋白(GFP)的表达及PCR技术,Western blot等方法鉴定重组腺病毒,并进行病毒滴度测定.结果 人TLR4胞外区基因重组腺病毒载体构建正确,病毒滴度为3.2×109pfu/mL.结论 成功构建了人TLR4胞外区基因重组腺病毒载体,为下一步实验奠定基础.     

人TLR2和TLR4胞外区cDNA的克隆

目的 从脂多糖诱导的外周血单个核细胞克隆人Toll样受体2(TLR2)和Toll样受体4(TLR4)胞外区cDNA.方法 用不同浓度脂多糖在不同时间刺激单个核细胞后提取总RNA,RT-PCR方法半定量测定TLR2和TLR4的表达,应用pUCm-T载体克隆胞外区cDNA,双酶切以及DNA测序进行鉴定.结果 单个核细胞在四种浓度脂多糖刺激3 h,6 h和12 h后.TLR2和TLR4表达并不相同.15 μg/mL脂多糖作用6 h TLR2表达最高,10 μg/mL脂多糖作用3 hTLR4表达最高.经RT-PCR扩增TLR2和TLR4胞外区cDNA分别为1 700 bp和1 900 bp,T载体克隆、酶切鉴定及测序分析后证实,目的 片段与GenBank中序列一致.结论 脂多糖的诱导对外周血单个核细胞TLR2和TLR4表达有显著影响,并且成功克隆了胞外区cDNA.     

pri-miR-21重组腺病毒载体构建及其对TLR4基因调控的研究

目的:构建能高效表达成熟miR-21小分子的腺病毒载体,探讨其对TLR4基因的靶向调控关系。方法:以正常小鼠基因组DNA为模板,PCR扩增pri-miR-21基因,克隆至穿梭载体pAdTrack-CMV中经PCR、酶切及基因测序分析正确无误后,与pAdEasy-1腺病毒骨架质粒进行同源重组,并利用293A细胞,包装成pri-miR-21重组腺病毒感染HeLa细胞,通过Western blot检测TLR4的蛋白表达水平,验证miR-21与TLR4靶向调控的关系。结果:经PCR、酶切、测序及GFP表达证实,成功构建携带pri-miR-21基因的重组腺病毒载体并制备出高滴度重组病毒。Western blot证实,miR-21可抑制TLR4蛋白的表达。结论:所制备的小鼠pri-miR-21重组腺病毒,可以高效表达成熟miR-21小分子,能够抑制靶基因TLR4的表达。     

大鼠siTLR4重组腺病毒载体的构建及功能鉴定

目的构建特异性针对大鼠TLR4基因的siRNA重组腺病毒载体,为进一步研究TLR4在不同疾病中的免疫调节机制奠定重要基础。方法设计并合成3对大鼠TLR4基因的siRNA序列,退火处理后定向克隆到pSES-HUS穿梭质粒中,获得pSES-HUS-siTLR4,经Pme I线性化后与pAdEasy-1骨架质粒在BJ5183细菌中进行同源重组,从而构建pAd-siTLR4质粒,通过脂质体转染,在HEK293细胞中包装形成Ad-siTLR4腺病毒颗粒,用该病毒感染PC12细胞,从基因和蛋白质水平分别检测3对siTLR4的抑制效果,同时从蛋白质水平检测TLR4下游关键分子NF-κB的表达。结果 PCR、酶切和测序均证实目的基因正确克隆到所构建的pAd-siTLR4重组腺病毒载体中;经包装获得的Ad-siTLR4病毒颗粒在PC12细胞中能够有效地抑制TLR4 mRNA和蛋白水平的表达,并显著地降低了NF-κB的表达。结论成功构建了pAd-siTLR4重组腺病毒质粒,同时包装获得了Ad-siTLR4重组腺病毒,转染PC12细胞后不仅能明显降低TLR4的表达,而且有效地抑制了TLR4通路下游关键分子NF-κB的表达。     

人IL-2重组腺病毒转染人肺腺癌细胞的体外生物学特性及体内抗肿瘤研究

目的 :研究感染hIL 2重组病毒的人肺腺癌细胞 (Anip973)的体外生物学特性及小鼠体内抗肿瘤作用。方法 :将携带有hIL 2基因的重组腺病毒 (rAd hIL 2 )感染人肺腺癌细胞系 ,通过细胞生长实验、克隆形成实验等观察其对Anip973肿瘤细胞的作用 ;利用PCR技术对转染后的细胞进行检测并应用ELISA试剂盒检测转染后的细胞IL 2的分泌量 ;通过肿瘤局部注射rAd hIL 2的方法观察其在小鼠体内的抗肿瘤作用。结果 :rAd hIL 2经扩增、纯化后 ,滴度可达 10 1 0 PFU ml,当病毒量为30MOI时 ,对Anip973细胞的转染率达 90 %以上。转染的Anip973肿瘤细胞其生长能力、克隆形成率等无明显变化。 2 4小时细胞培养上清IL 2的分泌量为 2 0pg 1ml 2× 10 5细胞。体内实验表明注射rAd hIL 2的小鼠肿瘤生长缓慢 ,体积明显小于对照组 (P <0 0 5 ) ,生存期显著延长。结论 :腺病毒介导的细胞因子基因hIL 2转染的Anip973肿瘤细胞体外生物学特性未见明显变化 ,而体内实验则有明显的抗肿瘤作用。     

抗人Toll样受体4单克隆抗体的制备及其生物活性研究

目的运用单克隆抗体技术制备抗人Toll样受体4(TLR4)单克隆抗体(mhTLR4抗体),并鉴定其生物学活性。方法以重组人TLR4(rhTLR4)作为抗原,腹腔注射免疫Balb/c小鼠。分离小鼠脾脏B淋巴细胞与骨髓瘤细胞融合并培养,挑选阳性杂交瘤细胞,扩大培养,制备和鉴定mhTLR4其生物学效应。结果经3次免疫后的小鼠血清中抗rhTLR4抗体的效价具有较高水平的表达。1∶500的小鼠免疫血清可明显抑制人PBMC的TNF-α表达。分离小鼠脾细胞与骨髓瘤细胞进行融合,获得3株阳性单克隆杂交瘤细胞。其中2株经过增殖培养、纯化浓缩制备出较高产量的鼠抗人TLR4单克隆抗体。生物学活性测定表明,产生的抗rhTLR4单克隆抗体,能够明显地阻断脂多糖(LPS)诱导的人PBMC细胞对TNF-α的表达。结论本文制备的鼠抗人TLR4单克隆抗体,经鉴定具有较高的阻断内毒素信号传导的效应。为进一步研制人源化抗TLR4抗体、研制新一代抗内毒素靶向药物奠定了基础。     

鼠IL-28重组腺病毒体外抗肺癌活性研究

目的 将已成功构建的mIL-28A重组腺病毒载体转染至肺腺癌细胞LA795,并对其抗肺癌细胞生物学活性进行研究.方法 将Ad-pshuttle-cmv-mIL-28A转染至LA795细胞,用PCR、免疫细胞荧光、Tunel、Annexin V及MTT法等进行检测.结果 LA795细胞转染Af-mIL-28A后,MiL-28A的mRNA基因表达明显增加,且细胞内明显表达IL-28蛋白,LA795细胞凋亡增多,细胞生长明显抑制.结论 成功构建的mIL-28A重组腺病毒载体转染至肺腺癌细胞LA795后表达IL-28,且可能通过促进细胞凋亡而抑制其一定程度的生长.

Abstract：

Objective To transfect the recombinant mIL-28A adenovirus vector into lung adenocarcinoma cell line LA795 and research its anticancer activity. Methods Transfected the constructed mouse IL-28(mIL-28) recombinant adenovirus vector into LA795 cell line, detected with PCR, immunocytal fluorescence, Tunel, Annexin V and MTT. Results Transfected with rAd-mlL-28A into the LA795 cells, mIL-28A gene expression products mRNA increased obviously, IL-28 expression was detected in cells obviously,apoptosis cell number increased, and the growth of LA795 cells transfected with rAd-mIL-28A were inhibited obviously. Conclusion The recombinant miL-28A adenovirus vector we have constructed, which expresses IL-28 when transfected to lung adenocarcinoma cell line LA795, inhibits growth of carcinoma cell to some extent, and may work by promoting the apoptosis of cancer cells.     

重组腺病毒介导IFN-γ基因转染的巨噬细胞的体外免疫效应功能分析

巨噬细胞既是免疫效应细胞又是抗原提呈细胞，为研究ＩＦＮ－γ基因转染的巨噬细胞过继回输疗法，以重组腺病毒为载体将小鼠ＩＦＮ－γｃＤＮＡ转染入小鼠腹腔巨噬细胞，观察了对其体外免疫功能的影响，结果表明，ＩＦＮ－γ基因转染１８ｈ后巨噬细胞上清中存在高水平ＩＦＮ－γ，ＩＦＮ－γ基因转染的巨噬细胞杀伤活性显著增高，其分泌ＴＮＦ、ＩＬ－１、ＮＯ的水平均有不同程度的升高，表明重组腺病毒载体能将ＩＦＮ－γ基因成功地转染入巨噬细胞并增强巨噬细胞免疫效应功能。     

CTRP4 acts as an anti-inflammatory factor in macrophages and protects against endotoxic shock

Despite the availability of antibiotics, current therapies to treat sepsis are still ineffective and many clinical trials aimed at neutralizing specific inflammatory cytokines have failed, suggesting the urgent need for new treatments. Using two models of LPS-induced endotoxemia and cecal ligation and puncture (CLP)–induced sepsis, we investigated the effects of C1q/TNF-related protein 4(CTRP4) on septic lethality and sepsis-induced inflammation. The effects of CTRP4 on survival, inflammation, organ damage, and bacterial clearance were assessed. Here, we found that CTRP4 decreased the mortalities of mice and alleviated pathological lung injury in mice model. In vivo depletion and adoptive transfer studies showed CTRP4-expressing macrophages as the key cell type inhibiting LPS-induced septic shock. The mechanism associated with the CTRP4 deficiency involved promoting of TLR4 internalization and activation of downstream pathways that resulted in a lethal, prolonged proinflammatory cytokine storm. Treatment of macrophages with exogenous CTRP4 abrogated proinflammatory cytokine production. Our results showed CTRP4 regulates inflammatory response and could be a promising strategy to treat septic shock.     

Lipid A antagonist, lipid IVa, is distinct from lipid A in interaction with Toll-like receptor 4 (TLR4)-MD-2 and ligand-induced TLR4 oligomerization

Toll-like receptor 4 (TLR4) and MD-2 recognizes lipid A, the active moiety of microbial lipopolysaccharide (LPS). Little is known about mechanisms for LPS recognition by TLR4-MD-2. Here we show ligand-induced TLR4 oligomerization, homotypic interaction of TLR4, which directly leads to TLR4 signaling. Since TLR4 oligomerization normally occurred in the absence of the cytoplasmic portion of TLR4, TLR4 oligomerization works upstream of TLR4 signaling. Lipid IVa, a lipid A precursor, is agonistic on mouse TLR4-MD-2 but turns antagonistic on chimeric mouse TLR4-human MD-2, demonstrating that the antagonistic activity of lipid IVa is determined by human MD-2. Binding studies with radioactive lipid A and lipid IVa revealed that lipid IVa is similar to lipid A in dose-dependent and saturable binding to mouse TLR4-human MD-2. Lipid IVa, however, did not induce TLR4 oligomerization, and inhibited lipid A-dependent oligomerization of mouse TLR4-human MD-2. Thus, lipid IVa binds mouse TLR4-human MD-2 but does not trigger TLR4 oligomerization. Binding study further revealed that the antagonistic activity of lipid IVa correlates with augmented maximal binding to mouse TLR4-human MD-2, which was approximately 2-fold higher than lipid A. Taken together, lipid A antagonist lipid IVa is distinct from lipid A in binding to TLR4-MD-2 and in subsequent triggering of TLR4 oligomerization. Given that the antagonistic activity of lipid IVa is determined by MD-2, MD-2 has an important role in a link between ligand interaction and TLR4 oligomerization.     

Soluble ST2 protein inhibits LPS stimulation on monocyte-derived dendritic cells

ST2 protein is a soluble splicing variant of ST2L protein, which is the receptor for interleukin-33 (IL-33). Previously, we reported that soluble ST2 suppressed the signal transduction of lipopolysaccharide (LPS) and cytokine production in monocytic cells. To investigate whether or not this inhibitory effect occurs in dendritic cells, which are the key players in innate and adaptive immunity, human monocyte-derived dendritic cells were pre-treated with soluble ST2 protein before LPS stimulation. Although soluble ST2 did not attenuate the LPS-induced maturation of dendritic cells, pre-treatment with soluble ST2 suppressed cytokine production and inhibited LPS signaling. Moreover, the proliferation of naive T cells was inhibited significantly by soluble ST2 pre-treatment. IL-33 had little effect on the cytokine production of immature monocyte-derived dendritic cells. Furthermore, soluble ST2 protein was internalized into dendritic cells, suggesting that soluble ST2 protein acts by a noncanonical mechanism other than the sequestration of IL-33.     

Higher Monocyte Expression of TLR2 and TLR4, and Enhanced Pro-inflammatory Synergy of TLR2 with NOD2 Stimulation in Sarcoidosis

Introduction  Sarcoidosis is an inflammatory disease of unknown etiology. However, an infectious cause has been proposed suggesting a role for pattern-recognition receptors, such as Toll-like receptors (TLRs) and nucleotide-binding domain, leucin-rich repeat containing family proteins (NLRs), in the pathogenesis. Objective  Our aim was to investigate whether differences in TLR2 and TLR4 expression, and the response to TLR2, TLR4, and NOD2 stimulation, are associated with sarcoidosis. Materials and Methods  Blood mononuclear cells from sarcoidosis patients (n = 24) and healthy subjects (n = 19) were incubated with the TLR2 ligands PGN and Pam3CSK4, the TLR4 ligand LPS, the NOD2 ligand MDP, or medium alone. After 16 h, monocyte TLR2 and TLR4 expression and cytokine secretion, including TNFα, IL-1β, IL-6, IL-8, IL-10, and IL-12p70, were measured using flow cytometry and cytometric bead array. Results  TLR2 and TLR4 expression at baseline was significantly higher in patients. Combined TLR2 and NOD2 stimulation induced a four-fold higher secretion of TNFα and a 13-fold higher secretion of IL-1β in patients. Additionally, there was a synergistic effect of TLR2 with NOD2 stimulation on induction of IL-1β in patients, whereas IL-10 was synergistically induced in healthy subjects. Conclusion  Increased TLR expression and enhanced secretion of pro-inflammatory cytokines after combined TLR2 and NOD2 stimulation may be related to the pathogenesis of sarcoidosis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. This study was supported by the Swedish Heart–Lung Foundation, King Oscar II Jubilee Foundation, the Swedish Research Council, the U.S. National Institutes of Health (Grant No. 1 R21 HL077579-01), the Stockholm County Council and Karolinska Institutet.     

Toll样受体2和Toll样受体4在HBV感染后的免疫作用

Toll样受体（TLR）是启动固有免疫和调节适应性免疫的重要分子,参与肝脏对病毒及细菌的免疫TLR2、TLR4过程。在HBV的慢性化进程中,TLR2、TLR4与Thl和Th2的免疫平衡及调节性T细胞（Treg）的免疫抑制相关,HBV感染后,HBcAg刺激巨噬细胞产生TNF—α的作用需要TLR2参与,HBeAg的表达与否与TLR2的表达状态有关,而TLR4通过诱导iNOS的表达和激发HBV特异性免疫在体内抗HBV过程中起重要作用：     

Human MD-2 confers on mouse Toll-like receptor 4 species-specific lipopolysaccharide recognition.

Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS). MD-2 is associated with TLR4 and imparts LPS responsiveness to it. Little is known, however, as to whether MD-2 directly regulates LPS recognition by TLR4. To address the issue, we took advantage of a species-specific pharmacology of lipid IVa, an analogue of lipid A. Lipid IVa acted agonistically on mouse (m) TLR4/MD-2 but not on human (h) TLR4/MD-2. Lipid IVa antagonized the agonistic effect of lipid A on hTLR4/MD-2. We examined the chimeric complex consisting of mTLR4 and hMD-2 to ask whether species specificity is conferred by TLR4 or MD-2. hMD-2 was clearly distinct from mMD-2 in the way of influencing LPS recognition by mTLR4. hMD-2 conferred on mTLR4 responsiveness to lipid A but not to lipid IVa. Moreover, lipid IVa acted as a lipid A antagonist on mTLR4 that is associated with hMD-2. Collectively, MD-2 directly influences the fine specificity of TLR4.