The interaction of host genetic factors and <Emphasis Type="Italic">Helicobacter</Emphasis> <Emphasis Type="Italic">pylori</Emphasis> infection

Helicobacter pylori plays an important role in the development of atrophic gastritis that represents the most recognized pathway in multistep gastric carcinogenesis. Recent studies suggest that a combination of host genetic factors, bacterial virulence factors, and environmental and lifestyle factors determine the severity of gastric damage and the eventual clinical outcome of Helicobacter pylori infection. As to bacterial virulence factors, a high proportion of Japanese strains are cagA⁺vacAs1. The CagA protein is injected from attached Helicobacter pylori into gastric epithelial cells and the CagA-SHP-2 interactions elicit cellular changes that increase the risk of carcinogenesis. Host cytokine gene polymorphisms and a frequent single nucleotide polymorphism in the PTPN11 gene that encodes SHP-2 may associate with gastric atrophy among Helicobacter pylori-infected subjects. Prevention of gastric cancer requires the development of better screening strategies for determining eradication candidates and further improvement of treatments of Helicobacter pylori infection. Received 6 August 2006; accepted 21 August 2006     

乳酸杆菌对不同体质母亲母乳成分的影响

目的本研究通过给过敏体质孕母、乳母补充益生菌乳酸杆菌,观察乳酸杆菌对母乳成分的影响及其与婴儿过敏性疾病发病的关系。方法选择过敏体质孕妇（n=60）,随机分成两组,一组自孕36周开始口服乳酸杆菌,孩子出生后继续服用直到母乳喂养结束,另一组口服安慰剂,同时选择非过敏体质孕妇（n=30）为对照组,生后取母乳测细胞因子及免疫球蛋白（IgA、skA、TGF-β1,sCD14）,孩子随访到2岁以确定湿疹及其他过敏性疾病。结果口服乳酸杆菌的孕妇母乳中TGF—β1、sCD14水平较口服安慰剂低,口服乳酸杆菌的孕妇的孩子2岁内患过敏性疾病率低。口服乳酸杆菌对母乳中IgA、sIgA水平没有影响。结论在怀孕晚期及哺乳期口服乳酸杆菌可降低母乳中TGF-β、sCD14水平,这种细胞因子水平降低与母乳喂养婴儿低敏感性有相关性。     

肝纤维化病程中Kupffer细胞与HSC的相互关系（综述）

肝纤维化（HF）是诸多慢性肝病共同的病理过程,也是各种慢性肝病向肝硬化转归的中转站。肝星状细胞（HSC）是细胞外基质（ECM）的主要来源,在肝纤维化形成中起关键性作用。枯否细胞（KC）是肝脏内重要的非实质细胞,KC通过分泌一系列细胞因子参与HSC的活化。参与肝纤维化的发生与发展。在肝纤维化的恢复阶段,KC可抑制HSC活性,促进其凋亡从而发挥抗纤维化作用。因此,深入研究Kupffer细胞与HSC的Cross-talk在肝纤维化的发生与发展中的作用和机制,对于临床工作中防治肝脏损伤,提高患者生存率具有实际意义。     

Bacterially expressed recombinant envelope protein domain III of Japanese encephalitis virus (rJEV-DIII) elicits Th1 type of immune response in BALB/c mice

Japanese encephalitis is a major cause of encephalitis in Asia. Cases occur largely in rural areas of the South and East Asian region resulting in significant morbidity and mortality. Multiple vaccines exist to control Japanese encephalitis, but all suffer from problems. Envelope protein domain III of Japanese encephalitis virus is involved in binding to host receptors and it contains specific epitopes that elicit virus-neutralizing antibodies. Earlier, the protective efficacy of domain III has been evaluated in mice by some researchers, but these studies are lacking in explanation of humoral and cellular immune responses. We have earlier reported cloning, expression, purification and in vitro refolding of Japanese encephalitis virus envelope protein domain III (rJEV-DIII). Ninety percent JEV is neutralized when the serum against refolded rJEV-DIII is used at a dilution of 1:80. In the present study, we have evaluated the immunomodulatory potential of refolded rJEV-DIII protein in BALB/c mice with Freunds complete/incomplete adjuvants. Mice were tested for humoral immune response by ELISA. Cell-mediated immune response was tested by lymphocyte proliferation assay and cytokine profiling. The rJEV-DIII generated high IgG antibody and its isotypes (IgG2a and IgG3) and induced significant expression of INF-γ and IL-2 cytokines. The rJEV-DIII induced significant lymphoproliferation of splenocytes. In conclusion rJEV-DIII induced Th1 type of immune response which plays an important role in protection for intracellular pathogens.     

独一味对内毒素血症BALB／c小鼠血清细胞因子的影响

目的检测独一味预处理对内毒素血症BALB／C小鼠血清细胞因子水平的影响,初步探讨独一味对炎症的调节机制。方法用独一味浸膏液对雄性BALB／c小鼠进行灌胃预处理,5d后给予内毒素促使内毒素血症的发生,6h后动物断头取血,制备血清样品,利用LiquiChip系统检测血清细胞因子水平。结果细胞因子检测发现,非致死性内毒素血症6h时血清细胞因子普遍增高,为正常水平的数倍到数百倍（P〈0．01）。给予独一味处理可以改变内毒素血症细胞因子的血清水平,使血清MCP-1约下降20％（P〈0．01）,血清TNFa约下降40％（P〈0．01）,使血清IL-1β约上升1倍（P〈0．01）,血清IL-4上升了37％（P〈0．01）,血清IL-10约上升20％（P〈0．01）,独一味对血清IL-6水平没有明显影响（P〉0．05）。结论独一味对内毒素血症不同细胞因子的调节不同,具有选择性和多样性。其提高了抗炎细胞因子的水平,减少了部分促炎因子的表达,避免发生过激的炎症反应,保护机体组织,且同时还提高IL-1等促炎细胞因子的表达,增强机体的天然免疫机制。     

The type 1 TNF receptor and its associated adapter protein,FAN, are required for TNFα-induced sickness behavior

RATIONALE: During the course of an infection, the pro-inflammatory cytokine tumor necrosis factor alpha (TNFalpha) acts in the brain to trigger development of behavioral responses, collectively termed sickness behavior. Biological activities of TNFalpha can be mediated by TNF receptor type 1 (TNF-R1) and type 2 (TNF-R2). TNFalpha activates neutral sphingomyelinase through the TNF-R1 adapter protein FAN (factor associated with neutral sphingomyelinase activation), but a behavioral role of FAN in the brain has never been reported. OBJECTIVES: We hypothesized that TNFalpha-induced sickness behavior requires TNF-R1 and that FAN is a necessary component for this response. MATERIALS AND METHODS: We determined the role of brain TNF-R1 in sickness behavior by administering an optimal amount of TNFalpha intracerebroventricularly (i.c.v., 50 ng/mouse) to wild-type (WT), TNF-R1-, TNF-R2-, and FAN-deficient mice. Sickness was assessed by decreased social exploration of a novel juvenile, induction of immobility, and loss of body weight. RESULTS: TNF-R1-deficient mice were resistant to the sickness-inducing properties of i.c.v. TNFalpha, whereas both TNF-R2-deficient and WT mice were fully responsive. Furthermore, the complete absence of TNFalpha-induced sickness behavior in FAN-deficient mice provided in vivo evidence that FAN-dependent TNF-R1 signaling is critical for this central action of TNFalpha. CONCLUSIONS: This is the first report to demonstrate that TNFalpha-induced sickness behavior is fully mediated by TNF-R1 and that the adaptor protein FAN is a necessary intracellular intermediate for sickness behavior.     

Infection and maturation of monocyte-derived human dendritic cells by human respiratory syncytial virus, human metapneumovirus, and human parainfluenza virus type 3

Human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), and human parainfluenza virus type 3 (HPIV3) are common, important respiratory pathogens, but HRSV has a substantially greater impact with regard to acute disease, long-term effects on airway function, and frequency of re-infection. It has been reported to strongly interfere with the functioning of dendritic cells (DC). We compared HRSV to HMPV and HPIV3 with regard to their effects on human monocyte-derived immature DC (IDC). Side-by-side analysis distinguished between common effects versus those specific to individual viruses. The use of GFP-expressing viruses yielded clear identification of robustly infected cells and provided the means to distinguish between direct effects of robust viral gene expression versus bystander effects. All three viruses infected inefficiently based on GFP expression, with considerable donor-to donor-variability. The GFP-negative cells exhibited low, abortive levels of viral RNA synthesis. The three viruses induced low-to-moderate levels of DC maturation and cytokine/chemokine responses, increasing slightly in the order HRSV, HMPV, and HPIV3. Infection at the individual cell level was relatively benign, such that in general GFP-positive cells were neither more nor less able to mature compared to GFP-negative bystanders, and cells were responsive to a secondary treatment with lipopolysaccharide, indicating that the ability to mature was not impaired. However, there was a single exception, namely that HPIV3 down-regulated CD38 expression at the RNA level. Maturation by these viruses was anti-apoptotic. Inefficient infection of IDC and sub-optimal maturation might result in reduced immune responses, but these effects would be common to all three viruses rather than specific to HRSV.     

APOE genotype-specific differences in the innate immune response

Apolipoprotein-E protein is an endogenous immunomodulatory agent that affects both the innate and the adaptive immune responses. Since individuals with the APOE4 gene demonstrate worsened pathology and poorer outcomes in many neurological disorders, we examined isoform-specific differences in the response of microglia, the primary cellular component of the brain's innate immune response, in detail. Our data demonstrate that microglia derived from APOE4/4 targeted replacement mice demonstrate a pro-inflammatory phenotype that includes altered cell morphology, increased NO production associated with increased NOS2 mRNA levels, and higher pro-inflammatory cytokine production (TNFα, IL-6, IL12p40) compared to microglia derived from APOE3/3 targeted replacement mice. The effect is gene dose-dependent and increases with the number of APOE4 gene alleles. The APOE genotype-specific immune profile observed in the microglial immune response is also observed in the cortex of aged APOE3/3 and APOE4/4 mice treated with lipopolysacchride (LPS) and in peripheral (peritoneal) macrophages. To determine if APOE4's action resulted from an isoform-specific difference in effective levels of the apolipoproteins, we generated mice expressing only a single allele of APOE3. Immune-stimulated macrophages from APOE3/0 mice demonstrated an increased inflammatory response compared to APOE3/3 mice, but less than in APOE4/4 mice. These data suggest that inhibition of inflammation depends upon the dose of apoE3 protein available and that apoE4 protein may alter inflammation partly by dose effects and partly by being qualitatively different than apoE3. Overall, these data emphasize the important role of apolipoprotein E and of the APOE genotype on the immune responses that are evident in most, if not all, neurological disease.     

Role of human leukocyte antigen, killer-cell immunoglobulin-like receptors, and cytokine gene polymorphisms in leptospirosis

Leptospirosis is an emerging zoonotic disease caused by pathogenic species of the genus Leptospira. It has a broad range of clinical presentations in humans. Although progress has been made in the characterization of the host immune system factors that may affect disease progression and outcome, to date few reports have addressed the role of genetic polymorphisms in the susceptibility to leptospirosis. In this work a group of patients with a history of leptospiral infection and a control group were compared for polymorphisms in the human leukocyte antigen (HLA), in killer-cell immunoglobulin-like receptors (KIR), and in cytokine genes. Alleles in the HLA-A and -B loci were associated with susceptibility, as were the class I haplotype A*01-B*08-Cw*07 and the 8.1 ancestral haplotype (A*01-B*08-Cw*07-DRB1*03-DQB1*02). Single nucleotide polymorphisms in the interleukin (IL)-4 and IL-4Rα genes also had significantly higher frequencies in the patient group. No association was reported between KIR gene profile and leptospirosis. This work highlights the importance of using genetic polymorphisms to better understand the mechanisms involved in the immune response to leptospirosis.     

Homotypic T-cell/T-cell interaction induces T-cell activation, proliferation, and differentiation

Activated CD4 T cells might induce T-cell activation from CD4 resting T cells in the absence of antigen presenting cells through interaction of activation-induced surface molecules (e.g., CD80, CD86, CD70, major histocompatibility complex class II) and their ligands constitutively expressed on resting T cells. Supporting this hypothesis, CD4 memory T cells proliferated in response to contact with activated T cells and expressed activation markers, such as CD25, CD30, and CD69. Analysis of their cytokine profile revealed differentiation of interleukin (IL)–10 and interferon-γ double-producing cells in response to contact with activated T helper (Th) 1 effector cells, and interleukin (IL)–4-producing cells in response to contact with activated Th2 effector cells. Whereas neutralization of interferon–γ or IL-4 during co-culture did not diminish the frequency of the arising cytokine-producing cells, separation of the responder cells from effector cells significantly decreased cytokine secretion. Specific blocking of particular receptor/ligand interactions denoted above could not prevent cytokine production induced by T-cell/T-cell interaction. However, blockade of all of the receptor/counterreceptor pairs significantly inhibited cytokine production, although not completely. Given the immunomodulatory capacity of IL-4 and IL-10, these findings might indicate a novel contact dependent negative feedback mechanism to control T-cell–driven immunity.