High concentrations of human β-defensin 2 in gastric juice of patients with Helicobacter pylori infection

MIA： Human β-defensin （HBD）-1 and HBD-2 are endogenous antimicrobial peptides. Unlike HBD-1, the HBD-2 expression is augmented by Helicobacter pylori （H pylon）. We sought to determine HBD-1 and HBD-2 concentrations in gastric juice during Hpylori infection. METHODS： HBD-1 and HBD-2 concentrations were measured by radioimmunoassay in plasma and gastric juice of 49 Hpylori-infected and 33 uninfected subjects and before and after anti-H pyloritreatment in,13 patients with Hpylori-associated gastritis. Interleukin （IL）-1β and IL-8 concentrations in gastric juice were measured by enzyme-linked immunosorbent assay （ELISA）. Histological grades of gastritis were determined using two biopsy specimens taken from the antrum and corpus. Reverse phase high performance liquid chromatography （RP-HPLC） was used to identify HBD-2. RESULTS： HBD-2 concentrations in gastric juice, but not in plasma, were significantly higher in Hpylori-positive than -negative subjects, albeit the post-treatment levels were unchanged. Immunoreactivity for HBD-2 was exclusively identified in Hpylori-infected mucosa by RPHPLC. HBD-2 concentrations in gastric juice correlated with histological degree of neutrophil and mononuclear cell infiltration in the corpus. IL-1β levels correlated with those of IL-8, but not HBD-2. Plasma and gastric juice HBD-1 concentrations were similar in H pylori-infected and uninfected subjects. CONCLUSION： Our results place the β-defensins, especiallyHBD-2, in the front line of innate immune defence. Moreover, HBD-2 may be involved in the pathogenesis of Hpylori-associated gastritis, possibly through its function as immune and inflammatory mediator.

Human β-defensin 2 enhances IL-1β production and pyroptosis through P2X7-mediated NLRP3 expression in macrophages

Periodontal disease is the leading cause of tooth loss,which is also a high-risk factor for other diseases including oral cancer and cardiovascular disease.Periodontitis is one of the most common type of periodontal diseases.Interleukin-1β(IL-1β)plays a key role in the pathogenesis of periodontitis.However,the mechanism how IL-1βis produced during periodontitis is still unclear.In the present study,we found that humanβ-defensin 2(hBD2)enhances IL-1βproduction through an LPS-primed human acute monocytic leukemia(THP-1)macrophage model.Inhibition of P2X purinoceptor 7(P2X7)reduced hBD2-enhanced IL-1βproduction.Incubation of LPS-primed THP-1 macrophages with potassium chloride also suppressed hBD2-enhanced IL-1βproduction.Silence of inflammasome adaptor Nod-like receptor family pyrin domain containing 3(NLRP3)led to reduced hBD2-enhanced IL-1βproduction.Likewise,inhibition of caspase-1 also resulted in the decrease of IL-1β.Moreover,an ethidium bromide uptake test indicated that hBD2-activated caspase-1 mediated pyroptotic pore formation.Subsequent lactate dehydrogenase detection and flow cytometric analysis indicated that hBD2 also induced pyroptosis.In brief,these findings illustrated not only the mechanism of hBD2 in enhancing the inflammatory response,but also provided novel therapeutic targets for periodontitis.

HBD-2在尖锐湿疣患者皮损组织中表达的临床意义

尖锐湿疣（condyloma acuminatum，CA）是人乳头状病毒感染引起的性传播疾病之一，主要发生于外生殖器及肛门附近，主要病理表现为外生殖器、肛门区域皮肤黏膜的良性增生。近年来随着人们性观念的开放，包括CA在内的性传播疾病明显增多。复发率高，难以彻底根除是CA的主要特点，β-防御素-2（hunman β-defensin2，HBD-2）是广存在于人类皮肤和黏膜的抗菌肽分子，具有调节免疫和抗多种病原微生物的作用。作者通过测定30例CA病变组织中HBD-2表达，并与银屑病患者和健康对照组比较，以探讨HBD-2在CA发病和转归中的作用。报道如下。

鸡β-防御素cDNA的克隆与序列分析

使用总RNA提取试剂盒,从1月龄粤黄鸡骨髓细胞中分离提取总RNA,经过反转录PCR(RT＿PCR)扩增出鸡β＿防御素(Gal＿2)cDNA片段。PCR产物经凝胶回收纯化,加A尾后与载体pGEM＿TEasy相连,然后转化感受态细胞DH＿5α。在含X＿gal、IPTG的LA平板上筛选阳性克隆,经菌落PCR与提取质粒作限制性酶切鉴定后,对目的片段进行测序。结果表明RT＿PCR扩增出的cDNA片段碱基数为195bp,用Blast程序进行检索比较表明此扩增序列与Genbank中发表的鸡Gal＿2cDNA编码区序列100%相同。该cDNA编码64个氨基酸,包括信号肽、前片段和成熟肽,成熟肽由36个氨基酸残基组成。

Human β-defensin-2 Enhances Anti-tumor Efficacy of Survivin-based Broad-spectrum DNA Vaccine in Mouse Tumor Model

Objective:Malignant tumors greatly endanger and affect the quality of human life.Among antitumor biotherapy strategies,DNA vaccines hold promise in part because of their unique advantages.In this study,an effective broad-spectrum antitumor DNA vaccine expressing human survivin T34A dominant-negative mutant fused with humanβ-defensin-2(HBD2)was investigated.Methods:The expression profiles of genes of interest were examined using western blotting,reverse transcription-polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay(ELISA)in vitro.The immune function of the fusion gene vaccine(FGV)was assessed in BALB/c mice,which included detection of serum antibody,spleen lymphocyte proliferation,interferon-gamma(IFN-γ)secretion,and lactate dehydrogenase(LDH)release.In vivo antitumor effects of FGV were examined in a mouse breast cancer(4T1)model,whereas in vitro effects were assessed using tumor cells derived from different origins.Caspase-3activity in tumor cells was also assessed after vaccine transfection.Results:The FGV triggered humoral as well as cellular immune responses against survivin.It exhibited more potent inhibition of tumor growth as well as prolonged the survival of immunized mice compared to mice immunized with only either survivin T34A or HBD2 vaccines.In addition,FGV displayed stronger cytotoxicity against tumor cells derived from different origins compared to the other vaccines and facilitated increased caspase-3 activity in transfected tumor cells.Conclusion:The novel DNA vaccine consisting of a fusion of the universal tumor antigen survivin T34A mutant with molecular adjuvant HBD2generates enhanced broad-spectrum antitumor efficacy against cancers derived from various origins.

A tetrahedral framework nucleic acid based multifunctional nanocapsule for tumor prophylactic mRNA vaccination

Synthetic antigen-encoding mRNA plays an increasingly significant role in tumor vaccine technology owing to its antigen-specific immune-activation. However, its immune efficacy is challenged by inferior delivery efficiency and demand for suitable adjuvants. Here, we develop a novel mRNA nanovaccine based on a multifunctional nanocapsule, which is a dual-adjuvant formulation composed of cytosine-phosphateguanine motifs loaded tetrahedral framework nucleic acid(CpG-tFNA) and an immunopeptide murine β-defensin 2(mDF2β). This m RNA nanovaccine successfully achieves intracellular delivery, antigen expression and presentation of dendritic cells, and proliferation of antigen-specific T cells. In a tumor prophylactic vaccination model, it exerts an excellent inhibitory effect on lymphoma occurrence through cellular immunity. This mRNA nanovaccine has promising prophylactic applications in tumors and many other diseases.