Toll-like receptor (TLR)2 and TLR3 sensing is required for dendritic cell activation, but dispensable to control Schistosoma mansoni infection and pathology

Toll-like receptors (TLRs) play an important role in the innate recognition of pathogens by dendritic cells (DCs) and in the induction of immune responses. However, relatively little is known about their functions in innate/acquired responses to complex eukaryotic microorganisms, including helminth parasites. That Schistosoma mansoni eggs activate myeloid DCs through TLR2 and TLR3 has been shown by us and others, but the consequences of this combined activation are still unknown. We show that the engagement of both TLR2 and TLR3 by schistosome eggs is important for the production of inflammatory cytokines and interferon-stimulated genes, such as some chemokines, by DCs. Strikingly, DCs sensitized with ovalbumin in the presence of parasite eggs dramatically reduce the release of Th2-type cytokines by ovalbumin-specific T lymphocytes, an effect that fully depends on TLR3. Finally, although TLR2 and TLR3 have no role in host resistance and in egg-induced granuloma formation in S. mansoni-infected mice, they individually and additionally increase the Th1/Th2 balance of the immune response. Thus, TLR2 and TLR3 sensing is required to shape the immune response during murine schistosomiasis, but is dispensable to control infection and pathology.     

Ascaris lumbricoides pseudocoelomic body fluid induces a partially activated dendritic cell phenotype with Th2 promoting ability in vivo

Dendritic cells (DCs) matured with helminth-derived molecules that promote Th2 immune responses do not follow conventional definitions of DC maturation processes. While a number of models of DC maturation by Th2 stimuli are postulated, further studies are required if we are to clearly define DC maturation processes that lead to Th2 immune responses. In this study, we examine the interaction of Th2-inducing molecules from the parasitic helminth Ascaris lumbricoides with the maturation processes and function of DCs. Here we show that murine bone marrow-derived DCs are partially matured by A. lumbricoides pseudocoelomic body fluid (ABF) as characterised by the production of IL-6, IL-12p40 and macrophage inflammatory protein 2 (MIP-2) but no enhanced expression of cluster of differentiation (CD)-14, T-cell co-stimulatory markers CD80, CD86, CD40, OX40L and major histocompatibility complex class II was observed. Despite these phenotypic characteristics, ABF-stimulated DCs displayed the functional hallmarks of fully matured cells, enhancing DC phagocytosis and promoting Th2-type responses in skin-draining lymph node cells in vivo. ABF activated Th2-associated extracellular signal-regulated kinase-1 and nuclear factor-kB intracellular signalling pathways independently of toll-like receptor 4. Taken together, we believe this is the first paper to demonstrate A. lumbricoides murine DC-Th cell-driven responses shedding further light on DC maturation processes by helminth antigens.     

OX40 ligand regulates splenic CD8 dendritic cell-induced Th2 responses in vivo

In mice, splenic conventional dendritic cells (cDCs) can be separated, based on their expression of CD8α into CD8⁻ and CD8⁺ cDCs. Although previous experiments demonstrated that injection of antigen (Ag)-pulsed CD8⁻ cDCs into mice induced CD4 T cell differentiation toward Th2 cells, the mechanism involved is unclear. In the current study, we investigated whether OX40 ligand (OX40L) on CD8⁻ cDCs contributes to the induction of Th2 responses by Ag-pulsed CD8⁻ cDCs in vivo, because OX40–OX40L interactions may play a preferential role in Th2 cell development. When unseparated Ag-pulsed OX40L-deficient cDCs were injected into syngeneic BALB/c mice, Th2 cytokine (IL-4, IL-5, and IL-10) production in lymph node cells was significantly reduced. Splenic cDCs were separated to CD8⁻ and CD8⁺ cDCs. OX40L expression was not observed on freshly isolated CD8⁻ cDCs, but was induced by anti-CD40 mAb stimulation for 24 h. Administration of neutralizing anti-OX40L mAb significantly inhibited IL-4, IL-5, and IL-10 production induced by Ag-pulsed CD8⁻ cDC injection. Moreover, administration of anti-OX40L mAb with Ag-pulsed CD8⁻ cDCs during a secondary response also significantly inhibited Th2 cytokine production. Thus, OX40L on CD8⁻ cDCs physiologically contributes to the development of Th2 cells and secondary Th2 responses induced by Ag-pulsed CD8⁻ cDCs in vivo.     

Type I interferon is required for T helper (Th) 2 induction by dendritic cells

Type 2 inflammation is a defining feature of infection with parasitic worms (helminths), as well as being responsible for widespread suffering in allergies. However, the precise mechanisms involved in T helper (Th) 2 polarization by dendritic cells (DCs) are currently unclear. We have identified a previously unrecognized role for type I IFN (IFN‐I) in enabling this process. An IFN‐I signature was evident in DCs responding to the helminth Schistosoma mansoni or the allergen house dust mite (HDM). Further, IFN‐I signaling was required for optimal DC phenotypic activation in response to helminth antigen (Ag), and efficient migration to, and localization with, T cells in the draining lymph node (dLN). Importantly, DCs generated from Ifnar1^?/? mice were incapable of initiating Th2 responses in vivo. These data demonstrate for the first time that the influence of IFN‐I is not limited to antiviral or bacterial settings but also has a central role to play in DC initiation of Th2 responses.     

Impaired pro-inflammatory cytokine production and increased Th2-biasing ability of dendritic cells exposed to Taenia excreted/secreted antigens: A critical role for carbohydrates but not for STAT6 signaling

In cysticercosis, a parasitic disease caused by cestodes, the details of early interactions between parasite antigens and innate cells from the host are not well understood. In this study, the role of cestode-conditioned dendritic cells (DCs) in priming Th1 versus Th2 responses to bystander antigen was examined by using CD11c⁺ DCs as antigen-presenting cells and naive CD4⁺ DO11.10 lymphocytes specific to ovalbumin (OVA) as responding cells. No conventional maturation was induced in DCs exposed to Taenia crassiceps excreted/secreted antigens (TcES). The ability of TcES to affect Toll-like receptor (TLR)-mediated maturation and the pro-inflammatory response was analyzed by co-pulsing DCs with TcES and TLR ligands. DCs exposed to TcES blocked TLR4, TLR9 and Toxoplasma soluble antigen-induced phenotypic maturation. TcES-exposed DCs also blocked secretion of pro-inflammatory cytokines and alloreactive T cell proliferation, while preserving IL-10 production. DCs pulsed with TcES + OVA suppressed IFN-γ, whereas they induced greater IL-4 production by CD4⁺ DO11.10 cells. TcES with chemically-altered glycans failed to modulate TLR-mediated activation of DCs and their Th1-inhibitng ability, which was STAT6-independent. Our results reflect the capacity of TcES glyco-antigens to modulate Th1-type and inflammatory responses mediated through DC activation.     

特应性皮炎患儿外周血miR-122a和miR-146a水平与Th1/Th2/Th17免疫平衡的相关性分析

摘要 目的：探讨特应性皮炎（AD）患儿外周血微小核糖核酸（miRNA）-122a和miR-146a水平与辅助性T细胞（Th）1/Th2/Th17免疫平衡的相关性。方法：选取2020年5月～2023年5月石家庄市妇幼保健院皮肤科收治的AD患儿100例为AD组,根据特应性皮炎评分（SCORAD）分为轻度组31例、中度组41例、重度组28例,另选取同期100名体检健康儿童为对照组。采用实时荧光定量聚合酶链式反应检测外周血miR-122a、miR-146a水平,流式细胞术检测外周血Th1、Th2、Th17细胞比例,酶联免疫吸附法检测外周血Th1、Th2、Th17相关细胞因子[白细胞介素（IL）-2、干扰素-γ（IFN-γ）、IL-4、IL-13、IL-17、IL-22]水平,并计算Th1/Th2/Th17比值。采用Pearson/Spearman相关性分析AD患儿外周血miR-122a、miR-146a与Th1、Th2、Th17和相关细胞因子及Th1/Th2/Th17的相关性。结果：AD组外周血miR-122a、miR-146a、Th1、Th1/Th2/Th17、IL-2、IFN-γ水平低于对照组,Th2、Th17、IL-4、IL-13、IL-17、IL-22水平高于对照组（P均＜0.05）。轻度组、中度组、重度组外周血miR-122a、miR-146a、Th1、Th1/Th2/Th17、IL-2、IFN-γ水平依次降低,Th2、Th17、IL-4、IL-13、IL-17、IL-22水平依次升高（P均＜0.05）。Pearson/Spearman相关性分析显示,AD患儿外周血miR-122a、miR-146a与Th1、Th1/Th2/Th17、IL-2、IFN-γ水平呈正相关（r/rs分别为0.679、0.677、0.684、0.706、0.693、0.689、0.671、0.694,P均＜0.001）,与Th2、Th17、IL-4、IL-13、IL-17、IL-22呈负相关（r/rs分别为-0.690、-0.680、-0.681、-0.669、-0.675、-0.676、-0.676、-0.686、-0.682、-0.674、-0.680、-0.689,P均＜0.001）。结论：AD患儿外周血miR-122a、miR-146a水平降低,与病情严重程度密切相关,可能通过调节Th1/Th2/Th17免疫平衡参与AD发生发展。     

In vitro anti-tumor immune response induced by dendritic cells transfected with EBV-LMP2 recombinant adenovirus

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) is a high-incidence tumor in southern China. Latent membrane proteins 2 (LMP2) is a subdominant antigen of EBV. The present study was to develop a dendritic cells (DCs)-based cancer vaccine (rAd-LMP2-DC) and to study its biological characteristics and its immune functions. Our results showed that LMP2 gene transfer did not alter the typical morphology of mature DC, and the representative phenotypes of mature DC (CD80, CD83, and CD86) were highly expressed in rAd-LMP2-DCs. The expression of LMP2 in rAd-LPM2-DCs was about 84.54%, which suggested efficient gene transfer. Transfected DCs markedly increased antigen-specific T-cell proliferation. The specific cytotoxicity against NPC cell was significantly higher than that in controls (p < 0.05), and enhanced with increased stimulations by transfected DCs. In addition, phenotypic analysis demonstrated that the LMP2-specific CTLs consisted of both CD4(+) and CD8(+) T cells. These results showed that development of DC-based vaccine by transfection with malignancy-associated virus antigens could elicit potent CTL response and provide a potential strategy of immunotherapy for EBV-associated NPC.     

人参多糖注射液联合TP方案对晚期非小细胞肺癌患者Th1/Th2免疫平衡和血清肿瘤标志物的影响

摘要 目的：探讨人参多糖注射液联合多西他赛和顺铂（TP方案）治疗晚期非小细胞肺癌（NSCLC）的疗效及对患者辅助性T细胞（Th）1/Th2免疫平衡和血清肿瘤标志物的影响。方法：选取我院2019年3月~2021年2月收治的80例晚期NSCLC患者。按随机数字表法分为对照组（TP方案治疗,40例）和观察组（人参多糖注射液联合TP方案治疗,40例）。对比两组疗效、血清肿瘤标志物、Th1/Th2免疫平衡指标、生存质量和不良反应发生率。结果：观察组的客观缓解率、疾病控制率分别为55.00%、85.00%,分别高于对照组的32.50%、57.50%,差异有统计学意义（P<0.05）。两组治疗4个疗程后肺癌患者生存质量量表（FACT-L）各领域评分均较治疗前升高,且观察组高于对照组（P<0.05）。两组治疗4个疗程后血清肿瘤标志物糖类抗原19-9（CA19-9）、细胞角蛋-19片段（CYFRA21-1）、癌胚抗原（CEA）水平下降,且观察组低于对照组（P<0.05）。两组治疗4个疗程后血清γ-干扰素（INF-γ）、白介素-2（IL-2）水平升高,且观察组高于对照组（P<0.05）。两组治疗4个疗程后血清白介素-4（IL-4）、白介素-5（IL-5）水平降低,且观察组低于对照组（P<0.05）。两组不良反应发生率对比无统计学差异（P>0.05）。结论：晚期NSCLC在TP化疗基础上结合人参多糖注射液治疗,可更好的降低血清肿瘤标志物水平,控制疾病进展,同时还可调节Th1/Th2免疫平衡,促进患者生存质量改善。     

槐耳颗粒联合GP方案治疗晚期非小细胞肺癌的疗效及对Th1/Th2免疫平衡和血清肿瘤标志物的影响

摘要 目的：观察晚期非小细胞肺癌（NSCLC）采用吉西他滨+顺铂（GP方案）联合槐耳颗粒治疗的疗效及对Th1/Th2免疫平衡和血清肿瘤标志物的影响。方法：选取2020年01月~2022年02月期间来成都市第六人民医院接受治疗的晚期NSCLC患者80例。采用双色球法将患者分为对照组（40例,GP方案治疗）和研究组（40例,槐耳颗粒联合GP方案治疗）。对比两组临床疗效、血清肿瘤标志物[糖类抗原125（CA125）、癌胚抗原（CEA）、细胞角蛋白19片段21-1（CYFRA21-1）]、Th1/Th2免疫平衡和不良反应。结果：研究组客观缓解率、疾病控制率高于对照组（P<0.05）。两组不良反应发生率组间对比无差异（P>0.05）。研究组治疗后卡式评分（KPS）、Th1、Th1/Th2高于对照组（P<0.05）,Th2低于对照组（P<0.05）。治疗后研究组血清CA125、CYFRA21-1、CEA水平较对照组低（P<0.05）。结论：槐耳颗粒联合GP方案治疗晚期NSCLC,可有效降低血清CA125、CEA、CYFRA21-1水平,改善Th1/Th2免疫平衡,安全可靠。     

Induction of a T helper cell response against the tumor-associated antigen HER2 using monocyte-derived dendritic cells

Tumor-reactive CD4⁺ T helper (Th) cells play a criticalrole in antitumor immunity, due to their ability to induceCD8⁺ T cell-mediated cytotoxic activity and humoralresponse. This study focuses on the in vitro generationand expansion of Th cells specific for the tumor-associatedantigen `human epidermal growth factor receptor-2' (HER2). Aprotocol for efficient HER2 presentation was developed usingautologous monocyte-derived dendritic cells (DC) as antigenpresenting cells (APC) and purified HER2 protein as antigensource. Our data suggest that DC pulsed with recombinantprotein of the extracellular domain (ECD) of HER2 (ECD/HER2)induce an ECD/HER2-specific Th cell response. This finding mayfacilitate the development of immunotherapy regimens withoutrequiring defined immunogenic epitopes of the antigen.     

Transcript profiling of jasmonate‐elicited Taxus cells reveals a β‐phenylalanine‐CoA ligase

Plant cell cultures constitute eco‐friendly biotechnological platforms for the production of plant secondary metabolites with pharmacological activities, as well as a suitable system for extending our knowledge of secondary metabolism. Despite the high added value of taxol and the importance of taxanes as anticancer compounds, several aspects of their biosynthesis remain unknown. In this work, a genomewide expression analysis of jasmonate‐elicited Taxus baccata cell cultures by complementary DNA‐amplified fragment length polymorphism (cDNA‐AFLP) indicated a correlation between an extensive elicitor‐induced genetic reprogramming and increased taxane production in the targeted cultures. Subsequent in silico analysis allowed us to identify 15 genes with a jasmonate‐induced differential expression as putative candidates for genes encoding enzymes involved in five unknown steps of taxane biosynthesis. Among them, the TB768 gene showed a strong homology, including a very similar predicted 3D structure, with other genes previously reported to encode acyl‐CoA ligases, thus suggesting a role in the formation of the taxol lateral chain. Functional analysis confirmed that the TB768 gene encodes an acyl‐CoA ligase that localizes to the cytoplasm and is able to convert β‐phenylalanine, as well as coumaric acid, into their respective derivative CoA esters. β‐phenylalanyl‐CoA is attached to baccatin III in one of the last steps of the taxol biosynthetic pathway. The identification of this gene will contribute to the establishment of sustainable taxol production systems through metabolic engineering or synthetic biology approaches.     

A single plasmid transfection that offers a significant advantage associated with puromycin selection in Drosophila Schneider S2 cells expressing heterologous proteins

The Drosophila Schneider S2 (S2) Expression System enables expression of recombinant proteins constitutively, as well as inductively. This system can establish both transient and stable transformants with various selection markers. The generation of stable cell lines for increased expression or large scale expression of the desired protein is currently accomplished by cotransfection of both the expression and selection vectors. The selection vectors, pCoHYGRO and pCoBLAST, are commercially available using hygromycin-B and blasticidin S, respectively. Recently, we generated a plasmid, pCoPURO, for selection of transfected S2 cells using puromycin, which allows significant acceleration of the selection time. Although co-transfection of the selection marker with the plasmid for heterologous protein expression is functional in stable expression at short culture periods, the expression levels of stable transformants are continuously decreased during long culture times. To overcome this limitation, we generated pMT-PURO, a new plasmid that contains both the expression cassette and puromycin selection marker in a single plasmid. This system allows rapid selection and maintenance of the transformed S2 lines for extended culture periods.