Background: As an important mediator in lots of diseases, interleukin-9 (IL-9) can be a protector or pro-inflammatory cytokine depending on the complicated inflammatory milieu. Helicobacter pylori (H. pylori) induced a series of immunology cells and cytokines change, and however, the role of IL-9 in H. pylori infection remains unknown. Materials and methods: Wild-type and IL-9 deficient mice were infected with H. pylori by means of intragastric administration. The colonization of H. pylori bacteria was measured by detecting specific 16s rDNA, and the intensity of inflammation was observed by H&E stain. The expression level of inflammation cytokines was determined by ELISA and quantitative real-time PCR. Results: IL-9 was increased due to the attack of H. pylori, besides deletion of Il9 aggravated the bacterial colonization and inflammation intensity. In addition, treatment of rmIL-9 reduced colonized H. pylori and inflammation level, indicated that IL-9 was a protector for the host against this bacterium. Followed by the H. pylori infection, interferon (IFN)-gamma and interleukin (IL)-17A were up-regulated as expected, and nevertheless, the expression of IL-17A shared a positive relationship with IL-9 while IFN-gamma negative associated with IL-9. Moreover, we also proved that Treg cells were not involved in the protective effect of IL-9, and meanwhile, CD4(+)CD25(-) T cells secreted more IFN-gamma and less IL-17A in vitro due to the deletion of Il9. Conclusions: IL-9 plays a protective role against H. pylori and the protection associated with cytokines change including IFN-gamma and IL-17A.

Gastric cancer is one of the most common cancers and has the highest mortality rate worldwide. It is worthwhile to explore the mechanism of gastric cancer progression. An increasing number of studies have found that non-coding RNAs including miRNA and lncRNA play important roles in gastric cancer progression. This review summarized the role of ectopic miRNA in gastric cancer proliferation, growth, migration, invasion and apoptosis. Meantime, aberrantly expressed miRNA also received a great deal of attention as potential biomarker for gastric cancer diagnosis and therapy. Over the last decade, lncRNA was considered to regulate gastric cancer progression at the transcript and post-transcript level. At the transcript level, lncRNA induced gastric cancer progression by changing chromatin modification and mRNA stabilization to regulate mRNA and miRNA expression. Furthermore, lncRNA regulated gastric cancer progression by completely combining with miRNA to produce ceRNA or promote protein stabilization at the post-transcript level. Greater attention of miRNA and lncRNA in gastric cancer can provide new insight of mechanism of cancer development and may be acted as a new anticancer target.

In mice, antigen-specific CD4+ T cell response is indispensible for the protective immunity against Helicobacter pylori (H. pylori). It has been demonstrated that neuraminyllactose-binding hemagglutinin (HpaA) immunization protected mice from H. pylori infection in a CD4+ T cell dependent manner. However, much remains unclear concerning the human CD4+ T cell responses to HpaA. We conducted a systematic study here to explore the immunodominant, HpaA-specific CD4+ T cell responses in H. pylori infected individuals. We found that HpaA-specific CD4+ T cell responses varied remarkably in their magnitude and had broad epitope-specificity. Importantly, the main responses focused on two regions: HpaA76-105 and HpaA130-159. The HLA-DRB1*0901 restricted HpaA142-159 specific CD4+ T cell response was the most immunodominant response at a population level. The immunodominant epitope HpaA142-159 was naturally presented and highly conserved. We also demonstrated that it was not the broad peptide specificity, but the strength of HpaA specific CD4+ T cell responses associated with gastric diseases potentially caused by H. pylori infection. Such investigation will aid development of novel vaccines against H. pylori infection.

The route of vaccination plays an important role in the generation of protective immunity against pathogens. In one of our previous studies, subcutaneous (SC) immunization with Epivac had been shown to induce a local and systemic Th1-biased response but failed to provide complete protection. In this study, we investigated whether intranasal (IN) immunization with Epivac could protect against Helicobacter pylori infection to a greater extent than SC immunization. Despite the generation of high serum IgG levels via the two routes of vaccination, the protective effect was independent of the humoral response level. At 2-week post-challenge, examination of the IgG subclass response showed that a dominant IgG2a response was generated after IN immunization, which coincided with elevated IFN-γ production in both splenocytes and stomach homogenates, and a significant reduction in the H. pylori load was found. In contrast, a balanced Th1/Th2 response was induced by SC immunization at the same time point and no protective effect was observed. Two weeks later, the immune response in the SC vaccination groups shifted to Th1 and was equivalent in protection to the IN vaccination route. Our results showed that IN vaccination elicited earlier systemic and gastric Th1 response, which may contribute to the earlier protection compared to SC vaccination.

Helicobacter pylori ( H. pylori ) infects more than half of the world’s population, causing chronic gastritis, peptic ulcers and gastric cancer. Urease B subunit (UreB), a conserved protein of H. pylori , is capable of inducing specific CD4 + T-cell responses and provides protection against this infection. Previous studies have confirmed the effectiveness of rUreB subunit vaccines in generating CD4 + T-cell-mediated protection, but less is known regarding the roles of different subtypes of T-cell immunity, such as Th1, Th2 and Th17, particularly the immunodominant epitopes inducing specific CD4 + T-cell responses, in vaccine-mediated protection. In this study, we demonstrated that the vaccination of BALB/c mice with rUreB resulted in significant antigen-specific Th1 and Th17 immune responses. Importantly, two novel Th epitopes, UreB 317–329 and UreB 409–421 , which are recognized by a major population of CD4 + T cells, were identified in immunized mice. Our results demonstrated that two novel epitopes can simultaneously induce Th1 and Th17 immune responses; however, only the epitope vaccine-induced CD4 + T-cells secreting IFN-γ mediated the protection against H. pylori ; cells secreting IL-17A did not. Taken together, our results suggest that two novel immunodominant epitopes can induce Th1 and Th17 immune responses, but only the induced Th1 lymphocytes mediate protection against H. pylori .

Aim. To investigate the diagnostic yield and etiologies of patients with obscure gastrointestinal bleeding (OGIB) using capsule endoscopy (CE) or double-balloon enteroscopy (DBE). Method. We studied the data of 532 consecutive patients with OGIB that were referred to Xinqiao Hospital in Chongqing from December 2005 to January 2012. A lesion that was believed to be the source of the bleeding (ulceration, mass lesion, vascular lesion, visible blood, inflammation, or others) was considered to be a positive finding. We analyzed the diagnostic yield of CE and SBE and the etiologies of OGIB. Result. CE and SBE have similar diagnostic yields, at 71.9% (196/231) and 71.8% (251/304), respectively. The most common etiology was erosions/ulceration (27.1%) followed by mass lesion (19.4%) and angiodysplastic/vascular lesions (13.9%). By stratified analysis, we found that erosions/ulceration (27.1%) was the most common etiology for the 21–40-year age group. Mass lesion was the most common etiology in the 41–60-year age group. However, in the >60 years age group, angiodysplastic/vascular lesions were significantly increased compared with the other groups, even though erosions/ulceration was most common. Conclusion. In this study, we found that CE and SBE have similar diagnostic yields and erosions/ulceration was the most common reason for OGIB, followed by mass lesion and angiodysplasias.

目的 检测幽门螺杆菌(Helicobacter pylori,H.pylori)感染小鼠后胃黏膜细胞因子的水平变化情况,分析机体的免疫应答状态.方法 采用Real-Time-PCR法检测H.pylori感染小鼠后1、2、4及6周时胃黏膜H.pylori的定植数量及细胞因子(IFN-γ、IL-4、IL-10、IL-17A、Foxp3+)的mRNA表达水平,ELISA法测定胃黏膜IFN-γ、IL-4、IL-10、IL-17A的表达量.结果 感染小鼠胃黏膜中H.pylori的定植量随着时间的推移在第4周达到高峰,第6周时有所下降.感染小鼠胃黏膜IFN-γ的mRNA水平明显高于PBS对照组,并随时间逐渐升高.IL-4及IL-10在感染6周内无明显变化,IL-17A和Foxp3+的mRNA水平在1、2周时无明显变化,第4周时显著上升,第6周时下降.感染小鼠胃黏膜IFN-γ、IL-4和IL-17A的蛋白水平变化在第1、2周时无明显变化,第4周时显著上升,第6周时下降,而IL-10变化不明显.结论 H.pylori早期感染可显著激发Th1和Th17应答,并伴随Treg细胞反应,这些可能与H.pylori逃避宿主免疫清除后的持续性感染有关.

Staphylococcal enterotoxin B (SEB) is one of the most potent Staphylococcus aureus exotoxins (SEs). Due to its conserved sequence and stable structure, SEB might be a good candidate antigen for MRSA vaccines. Although cellular immune responses to SEB are well-characterized, much less is known regarding SEB-specific humoral immune responses, particularly regarding detailed epitope mapping. In this study, we utilized a recombinant nontoxic mutant of SEB (rSEB) and an AlPO4 adjuvant to immunize BALB/c mice and confirmed that rSEB can induce a high antibody level and effective immune protection against MRSA infection. Next, the antisera of immunized mice were collected, and linear B cell epitopes within SEB were finely mapped using a series of overlapping synthetic peptides. Three immunodominant B cell epitopes of SEB were screened by ELISA, including a novel epitope, SEB205-222, and two known epitopes, SEB97-114 and SEB247-261. Using truncated peptides, an ELISA was performed with peptide-KLH antisera, and the core sequence of the three immunodominant B cell epitopes were verified as SEB97-112, SEB207-222, and SEB247-257. In vitro, all of the immunodominant epitope-specific antisera (anti-SEB97-112, anti-SEB207-222 and anti-SEB247-257) were observed to inhibit SEB-induced T cell mitogenesis and cytokine production from splenic lymphocytes of BALB/c mice. The homology analysis indicated that SEB97-112 and SEB207-222 were well-conserved among different Staphylococcus aureus strains. The 3D crystal structure of SEB indicated that SEB97-112 was in the loop region inside SEB, whereas SEB207-222 and SEB247-257 were in the β-slice region outside SEB. In summary, the fine-mapping of linear B-cell epitopes of the SEB antigen in this study will be useful to understand anti-SEB immunity against MRSA infection further and will be helpful to optimize MRSA vaccine designs that are based on the SEB antigen.

目的 针对中国汉族高频HLA-DRB1基因型人群,预测与鉴定幽门螺杆菌(Helicobacter pylori,Hpylori)黏附素蛋白A亚单位(neuraminyllactose-binding hemagglutinin,HpaA)CD4+T细胞表位.方法 通过Allele Frequency Net数据库分析中国汉族人群HLA-DRB1高频基因型,利用NetMHCIIpan对HpaA蛋白中能被这些高频基因型递呈的CD4+T细胞表位进行预测;通过PCR-SBT法筛选携带有这些高频基因型的H.pylori感染者,利用重组HpaA抗原刺激感染者外周血单个核细胞体外扩增出HpaA抗原特异性T淋巴细胞后利用合成短肽对所预测表位进行鉴定,通过抗体阻断实验对表位的HLA限制性进行分析,利用DC细胞负载重组HpaA蛋白对表位的自然递呈特征进行分析.结果 中国汉族人群中HLA-DRB1高频基因型为DRB 1*0901 (14.4％)、DRB1*1202(13.3％)和DRB1*1501 (10.8％),针对上述3种高频基因型预测出24个HpaA蛋白CD4+T细胞表位.其中,4个表位:HpaA39-53(HLA-DRB 1*0901)、HpaA42-56(HLA-DRB1*0901)、HpaAsg-103(HLA-DRB1*1202)和HpaAs7-101(HLA-DRB1*1501)可有效刺激体外扩增的HpaA特异性T细胞产生高水平IFN-γ,且均能被DC细胞自然递呈.结论 鉴定得到的4个HLA-DRB1限制性CD4+T细胞表位有可能成为H.pylori表位疫苗设计的候选抗原.

BACKGROUND & AIMSImmunodominance is an important feature of antiviral, antitumor, and antibacterial cellular immune responses, but it is not well demonstrated in the immune responses against Helicobacter pylori. Antigen-specific CD4(+) T cells protect mice against infection with H pylori. We investigated the immunodominant CD4(+) T-cell response to neuraminyllactose-binding hemagglutinin (HpaA), which is a conserved, H pylori-specific colonization factor that is being investigated as an antigen for vaccination strategies.METHODSHpaA-specific CD4(+) T cells were expanded with autologous peripheral blood mononuclear cells that had been incubated with recombinant HpaA and characterized using overlapping synthetic peptides. We compared the percentage of CD4(+) T cells with specificity for HpaA(88-100), restricted to HLA-DRB1*1501, among 59 H pylori-infected subjects with different gastric diseases.RESULTSWe identified and characterized several immunodominant CD4(+) T-cell epitopes derived from HpaA. The immunodominant CD4(+) T-cell responses specific to HpaA(88-100) were observed in most H pylori-infected individuals who expressed HLA-DRB1*1501 and were significantly more abundant in patients with less severe diseases (P < .05).CONCLUSIONSThe HLA-DRB1*1501-restricted immunodominant CD4(+) T-cell response to HpaA(88-100) is associated with reduced risk of severe gastric diseases. Further study of these and other immunodominant CD4(+) T-cell responses to H pylori will provide insight into mechanisms of protective immunity and aid in vaccine design.

Background In recent years, the PLCE1 rs2274223 polymorphism has been extensively investigated as a potential risk factor for upper gastrointestinal cancers, including squamous cell carcinoma (ESCC) and gastric cancer. However, the results of these studies have been inconsistent. Methods A meta-analysis of 13 case-control studies was performed including more than 11,000 subjects with genotyped PLCE1 rs2274223 polymorphisms. Odds ratios (OR) with 95% confidence intervals (CI) were employed to assess the association of the PLCE1 rs2274223 polymorphism with a susceptibility to ESCC or gastric cancer. Results A statistically significant increase in the risk of ESCC was associated with the PLCE1 rs2274223 polymorphism. This included the homozygous genetic model (OR = 1.46), heterozygous genetic model (OR = 1.25) and allelic genetic model (OR = 1.23). Similar results were consistently found for gastric cancer. In a subgroup analysis, the PLCE1 rs2274223 polymorphism was found to be a very sensitive marker for gastric cardia cancer as shown by the homozygous genetic model (OR = 2.23), heterozygous genetic model(OR = 1.59) and allelic genetic model (OR = 1.47). The risk associations of all of the gastric cardia cancer models were statistically significant. In contrast, none of the genetic models for non-cardia gastric cancer were significant. Conclusions In this meta-analysis, the PLCE1 rs2274223 polymorphism was confirmed to have a statistically significant association with an increasing risk of ESCC and gastric cancer. The increase risk was especially observed for gastric cardia cancer.

Objective: To determine whether macrophage migration inhibitory factor (MIF) gene polymorphism is associated with the risk of inflammatory bowel disease (IBD).Design: System review and meta-analysis.Methods: MEDLINE, EMBASE, Web of Science databases, Cochrane Library and the Chinese Biomedical Literature database (CBM) were searched for the case-control trails for MIF and IBD. All the studies included in this manuscript met the inclusion and exclusion criteria. An OR analysis using a 95% CI was employed to assess the association of the MIF-173 G/C polymorphism with IBD susceptibility.Results: There was a significant association between the MIF-173 G/C gene polymorphism and IBD in the total population under the recessive model (CC vs GC +GG; OR=1.75, CI 1.04 to 2.95, p=0.04 for heterogeneity) and the codominant model (CC vs GG; OR=1.74, CI 1.02 to 2.97, p=0.04 for heterogeneity). In the stratified analysis by ethnicity, significantly increased risks were observed for Asians using the recessive (OR=1.75, CI 1.04 to 2.95, p=0.04 for heterogeneity) and codominant models (OR=1.74, CI 1.02 to 2.97, p=0.04 for heterogeneity). Within the subgroups of UC and CD, significant differences were observed regarding UC using the recessive (OR=1.60, CI 1.09 to 2.35, p=0.02 for heterogeneity) and codominant models (OR=1.64, CI 1.12 to 2.41, p=0.01 for heterogeneity). In the stratified analysis by ethnicity for UC, significant differences were observed regarding CC in Asians vs GC+GG (OR=1.73, CI 1.02 to 2.94, p=0.04 for heterogeneity).Conclusions: The meta-analysis suggested that the MIF-173 G/C polymorphism contributed to the susceptibility of IBD. When considering the subgroups of ethnicity and UC and CD, the results suggested that the polymorphism is more significant for UC in Asians.

<正>在临床治疗肿瘤疾病的过程中,不同患者对化疗药物的疗效和耐受性存在差异。虽然患者的年龄、器官功能、伴随治疗甚至生理周期对药物代谢和分布有一定的影响,但大部分都与单核苷酸多态性(single nucleotide polymorphism,SNP)有关,SNP可显著影响不同个体对药物的敏感性〔1〕。近年来大量临床观察显示,肿瘤患者使用伊立替康化疗的安

Objective To identify systematically MHC-restricted immunodominant T helper lymphocyte(Th) epitopes from urease subunit B of Helicobacter pylori(H.pylori) and to confirm the MHC-restricting profile.Methods BALB/c mice were immunized with recombinant UreB protein(rUreB) and Freund’s adjuvant by subcutaneous injection.Antigen-specific CD4+ T cells were amplified in vitro from spleens of immunized mice.The MHC-restricted immunodominant Th epitopes were identified by synthesizing overlapping peptides and antibody-blocking assay.Results UreB403-420and UreB409-426 induced the strongest secretion of IFN-γ in all the 93 18mer peptides,while 13mer peptide UreB403-426 within UreB403-420 and UreB409-426 induced equivalent responses compared with the 18mer peptides.The results of antibody-blocking assay showed that the H-2d(I-A) monoclonal antibody efficiently blocked the T cell activation induced by peptide UreB403-426.Conclusion UreB403-420 and UreB409-426 are immunodominant Th epitopes of urease subunit B antigen.The core reactive sequence is UreB409-421and its restriction molecule is H-2d(I-A).

<正>胃食管反流病(gastroesophageal reflux disease,GERD)是一种胃十二指肠内容物反流入食管引起食管及咽喉、气道等食管旁组织损伤的疾病,常见于餐后。GERD的发病机制极其复杂,目前认为主要是抗反流防御机制减弱[如食管下括约肌(lower esophageal sphincter,LES)功能减退,食管清除能力下降,胃排空延迟等]以及胃酸、胃蛋白酶、胆汁中的非结合胆盐和胰酶等主要反流物对食管粘膜的攻击作用〔1〕。在所有原因中,最为突出的是LES的功能减退。迄今为止对

Vaccine-mediated Th1-biased CD4+ T cell responses have been shown to be crucial for protection against Helicobacter pylori (H. pylori). In this study, we investigated whether a vaccine composed of CD4+ T cell epitopes together with Th1 adjuvants could confer protection against H. pylori in a mouse model. We constructed an epitope-based vaccine, designated Epivac, which was composed of predicted immunodominant CD4+ T cell epitopes from H. pylori adhesin A (HpaA), urease B (UreB) and cytotoxin-associated gene A product (CagA). Together with four different Th1 adjuvants, Epivac was administered subcutaneously and the prophylactic potential was examined. Compared to non-immunized mice, immunization with Epivac alone or with a Th1 adjuvant significantly reduced H. pylori colonization, and better protection was observed when an adjuvant was used. Immunized mice exhibited a strong local and systemic Th1-biased immune response, which may contribute to the inhibition of H. pylori colonization. Though a significant specific antibody response was induced by the vaccine, no correlation was found between the intensity of the humoral response and the protective effect. Our results suggest that a vaccine containing CD4+ T cell epitopes is a promising candidate for protection against H. pylori infection.

With the aim of design epitope-based vaccine against Helicobacter pylori(H.pylori),we identified and characterized H-2d restricted immunodominant Th epitopes from HpaA of H.pylori in this study.Immunodominant Th epitope of HpaA was identified by using in vitro expanded HpaA-specific T cells and overlapping synthetic peptides.And then,the H-2d subtype restriction of the epitope was analyzed by antibody blocking test.Mapping of 18 mer overlapping peptides showed that H154-171,H184-201,H190-207,H202-219 and H220-237 could stimulate HpaA-specific T cells to produce IFN-γ,and the response stimulated by H154-171 was the strongest.Mapping of 13 mer overlapping peptides showed that only H158-170 could stimulate an equivalent HpaA-specific T cell response with H154-171.Antibody blocking test showed that epitope H158-170 was restricted by H-2d(I-A).H154-171,H184-201,H190-207,H202-219 and H220-237 were H-2d restricted epitopes of HpaA,of which H154-171 was the immunodominant one,its core sequence was H158-170 and its restriction molecule was H-2d(I-A).All the result indicated that the epitope could be used for epitope-based vaccine design.