Involvement of ERK, p38 and NF-kappaB signal transduction in regulation of TLR2, TLR4 and TLR9 gene expression induced by lipopolysaccharide in mouse dendritic cells

Toll-like receptors (TLR) are sentinel receptors capable of recognizing pathogen-associated molecule patterns (PAMP) such as lipopolysaccharide (LPS) and CpG-containing oligonucleotides (CpG ODN). TLR2 and TLR4 are major receptors for Gram-positive and Gram-negative bacterial cell wall components, respectively. TLR9 is necessary for CpG signalling. LPS or CpG ODN can activate immature dendritic cells (DC) and induce DC maturation characterized by production of cytokines, up-regulation of co-stimulatory molecules, and increased ability to activate T cells. However, little is known regarding the regulation of TLR gene expression in mouse DC. In this study, we investigated the regulation of TLR2, TLR4 and TLR9 gene expression by LPS in murine immature DC. TLR2, TLR4 and TLR9 mRNA were up-regulated following LPS stimulation. The up-regulation of TLR9 expression coincided with significantly increased production of tumour necrosis factor-alpha induced by LPS plus CpG ODN. While inhibition of extracellular signal-related kinase and NF-kappaB activation suppressed the up-regulation of the expression of TLR2, TLR4 and TLR9 mRNA, inhibition of p38 kinase prevented the up-regulation of TLR2 and TLR4 mRNA expression but enhanced the up-regulation of TLR9 expression. These results demonstrated that TLR2, TLR4 and TLR9 gene expression was differently regulated by LPS in mouse immature DC. Up-regulation of TLR2, TLR4 and TLR9 expression by LPS might promote the overall responses of DC to bacteria and help to explain the synergy between LPS and other bacterial products in the induction of cytokine production.     

缺铁性贫血对学龄儿童某些认知能力影响的研究

本文采用双盲法对 IDA 和 NIDA学龄儿童各61名进行了认知能力测验及铁治疗前后的动态比较。结果表明:IDA 儿童识记再认、字母匹配反应时、数字扫描记忆和一般推理能力测验成绩较 NIDA 儿童差。经铁治疗的IDA 儿童,注意、短时记忆和心理动作反应速度均有明显提高。但对较高级认知能力的改善不明显。     

IL-12p40-overexpressing immature dendritic cells induce T cell hyporesponsiveness in vitro but accelerate allograft rejection in vivo: role of NK cell activation and interferon-gamma production

Infusion of genetically modified dendritic cells (DC) expressing immunosuppressive molecules is a potential therapy for organ rejection. IL-12p70, a cytokine produced mainly by DC and macrophages, consists of two subunits, p40 and p35. IL-12p70 is an activator of T cells, while the IL-12p40 subunit serves as a natural antagonist for IL-12p70 action. The primary aim of this study was to evaluate the effect of IL-12p40 gene-modification on both the T-cell stimulatory activity of immature DC (imDC) and their ability to prolong cardiac allograft survival. IL-12p40 gene-modified imDC (DC-p40) exhibited a phenotype characteristic of imDC and displayed impaired T-cell allostimulatory ability in vitro. However, to our surprise, for murine vascularized heterotopic heart transplantation (HHT), administration of donor-derived DC-p40 7 days prior to transplantation did not prolong allograft survival but instead significantly exacerbated cardiac allograft rejection. Further study showed that DC-p40 augmented NK cell activity both in vitro and in vivo and enhanced interferon-gamma (IFN-gamma) production in vivo, which might be due to the increased IL-23 production by DC-p40. Our data suggested that although IL-12p40 gene-modified immature DC can induce T cell hyporesponsiveness in vitro, their ability to activate NK cells and induce IFN-gamma production counterbalances this, exacerbating cardiac allograft rejection. The unexpected effects of DC-p40 limit their value in promoting allograft survival in vivo and likely reflect the complexity of IL-12p40 biology.     

树突状细胞负载肝癌抗原肽疫苗体外诱导特异性免疫学反应的研究

目的：研究树突状细胞(dendritic cell，DC)负载肝癌抗原肽EPVTKAEML体外诱导特异性CTL的能力及其抑癌效果。方法：用顺序特异引物聚合酶链反应技术(PCR—SSP)选择HLA—B7表型供者，从脾组织中分离、培养DC-EPVTKAEML特异性CTL。用^51Cr释放法检测CTL的杀伤活性，并用抗HLA-1分子单抗(mAb)进行杀伤抑制实验。结果：找到4例HLA-B7杂合子供者，用DC负载HLA-B7限制的抗原肽EPVTKAEML可诱导特异性CTL反应，对肝癌细胞HHCC有较强的杀伤作用。结论：DC负载抗原肽EPVTKAEML在体外可诱发较强的特异性免疫反应。     

骨髓基质细胞和壳聚糖/明胶共混材料生物相容性研究

目的:研究壳聚糖/明胶共混材料对离体培养的骨髓基质细胞粘附及增殖的影响,寻找骨髓基质细胞新的载体材料。方法:取2周龄幼兔的长骨采集骨髓,培养骨髓基质细胞,体外扩增1周后,种植于纯壳聚糖和壳聚糖/明胶共混材料的表面。在倒置光学显微镜、扫描电镜的辅助下,观察细胞的粘附和生长情况,种植7d后用透射电镜观察细胞功能状况,用MTT方法检测种植后2d、4d、6d、8d细胞的增殖情况。结果:壳聚糖/明胶共混材料和纯壳聚糖能促进骨髓基质细胞在材料表面粘附并保持其在机体内的形态。壳聚糖/明胶共混材料表面的骨髓基质细胞功能活跃。在材料表面和培养板表面培养的骨髓基质细胞均能持续增殖,而壳聚糖/明胶共混材料能显著促进骨髓基质细胞的增殖(P<0.01)。结论:壳聚糖/明胶共混材料保持了壳聚糖的某些生物活性,同时由于加入明胶,能促进骨髓基质细胞的增殖,可作为骨髓基质细胞的载体应用于组织工程。     

磷脂酰胆碱抗氧化效应及对遗传损伤的保护作用

磷脂酰胆碱５００ｍｇ／ｋｇ灌胃２０日可使Ｏ_３环境中的小鼠超氧化物歧化酶（ＳＯＤ）活性显著增强，血浆丙二醛（ＭＤＡ）含量及外周血正染红细胞（ＮＣＥ）微核率明显下降。结果提示：磷脂酰胆碱具有抗氧化作用及拮抗自由基造成遗传的损伤。进一步证实了自由基在微核形成中具有重要意义。     

Two antigens on zygotes and ookinetes of Plasmodium yoelii and Plasmodium berghei that are distinct targets of transmission-blocking immunity.

We have developed transmission-blocking monoclonal antibodies (MAbs) against Plasmodium yoelii 21-kDa (Pys21) and 28-kDa (Pys25) ookinete surface proteins. These MAbs block infectivity of P. yoelii to Anopheles stephensi. One MAb, 14, cross-reacted by Western blotting with a 28-kDa surface protein (Pbs25) of P. berghei ookinetes and blocked oocyst development, as assayed by direct mosquito feeds on passively immunized P. berghei-infected mice. In total, we have identified two ookinete surface proteins in P. yoelii, one of which is also present in P. berghei. The transmission-blocking activity of the anti-Pys25 MAb 4 was complete and more potent than that of the anti-Pys21 MAb 2. Moreover, Fab fragments of MAb 4 had transmission-blocking activity in mice. In comparison, Fab fragments of MAb 2 did not have detectable transmission-blocking effect, although F(ab')2 did. Furthermore, MAb 2 and MAb 4 appeared to block the in vitro formation and development of zygotes as well.     

新鲜羊膜致I型超敏反应的变应原性研究

研究新鲜人羊膜的变应原性及其致敏后发生I型超敏反应的可能性。建立豚鼠全身主动过敏实验模型。分新鲜羊膜组、新鲜蛋清组(阳性对照)和PBS液组(阴性对照),每组10只豚鼠。观察豚鼠在致敏期和激发后的反应,采用化学荧光法检测外周血组胺含量,血液流变分析系统检测4项血液流变学指标(全血高切变率黏度、全血低切变率黏度、血浆黏度、红细胞聚集指数)。致敏期间各组豚鼠的体重变化无明显差别(P>0.05);激发后羊膜组豚鼠与阴性组表现一致,无异常反应;羊膜组外周血组胺含量及4项血液流变学指标均与阴性对照无明显差别(P>0.05),与阳性对照有显著性差异(P<0.01)。经规范化无菌处理后的新鲜羊膜,一般不具有变应原性,不会引起I型超敏反应。     

莱姆病人工宿主动物模型的建立

为了建立莱姆病人工宿主模型进行实验传播研究,用从我国全沟硬蜱分离的莱姆病螺旋体Borrelia garinii CHNM4人工感染4种实验动物.结果表明,以0.1×106条/mL的剂量皮下注射3日龄昆明小鼠是比较理想的方案.由此建立的动物模型既能用作全沟硬蜱的血源动物,又能在15天内保持所感染螺旋体对全沟硬蜱的感染力,可作为人工宿主动物模型.     

PCR-based capsular serotype determination of Haemophilus influenzae strains recovered from Japanese paediatric patients with invasive infection

The serotypes of 53 isolates of Haemophilus influenzae from children with invasive infections were determined by a conventional slide agglutination test (SAT) and a recently proposed PCR-based method for serotyping H. influenzae. The PCR assay identified 47 (88.7%) type b isolates, one (1.9%) type e isolate and five (9.4%) non-typeable isolates. The only discrepancy between the methods was an isolate that was non-typeable by SAT, but was identified as serotype e by PCR. Of 41 isolates from patients with meningitis, 39 (95.1%) were type b. Of the five non-typeable isolates, three (60%) were from the blood of patients with septicaemic pneumonia and two (40%) were from the cerebrospinal fluid of patients with meningitis. None of the non-typeable isolates appeared to be a capsule-deficient mutant of an encapsulated H. influenzae strain. Overall, the study confirmed the usefulness of this PCR method for the serotyping of invasive H. influenzae isolates.