The Trimeric Autotransporter Adhesin SadA from spp. as a Novel Bacterial Surface Display System.

Bacterial surface display platforms have been developed for applications such as vaccine delivery and peptide library screening. The type V secretion system is an attractive anchoring motif for the surface expression of foreign proteins in gram-negative bacteria. SadA belongs to subtype C of the type V secretion system derived from spp.

Oral Administration of a 2aT32-Based Vaccine Expressing UreB-HspA Fusion Antigen With and Without Parenteral rUreB-HspA Boost Confers Protection Against in Mice Model.

() is a gram-negative pathogen classified as a class I carcinogen. The urease B subunit (UreB) and heat shock protein A (HspA) are two important vaccine candidate antigens. In this study, we evaluated the immunogenicity and immunoprotective effect of the attenuated vector vaccine SH02 expressing the UreB-HspA fusion protein of in a mouse model.

Efficient Genome Editing by a Miniature CRISPR-AsCas12f1 Nuclease in .

A miniature CRISPR-Cas12f has been demonstrated to serve as an effective genome editing tool in gram negative bacteria as well as human cells. Here, we developed an alternative method to edit the genome of based on the AsCas12f1 nuclease from . When the gene on the chromosome and the gene on the plasmid pXO1 were selected as targets, the CRISPR-AsCas12f1 system showed very high efficiency (100%).

Identification of B-Cell Epitopes of HspA from and Detection of Epitope Antibody Profiles in Naturally Infected Persons.

(), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni is an important co-factor required for the maturation and enzymatic activity of urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of .

Integrated Transcriptomic and Proteomic Analyses Reveal the Role of NprR in Extracellular Protease Expression Regulation and Oxidative Stress Responses.

NprR is a protein of that exhibits moonlighting functions as either a phosphatase or a neutral protease regulator that belongs to the RNPP family. We previously observed that the extracellular protease activity of an deletion mutant significantly decreased within cultures. To identify the genes within the regulatory network of that contribute to its protease activity, integrated transcriptomic and proteomic analyses were conducted here by comparing the deletion mutant and parent strains.

Highly Efficient Genome Engineering in and Using the CRISPR/Cas9 System.

Genome editing is an effective tool for the functional examination of bacterial genes and for live attenuated vaccine construction. Here, we report a method to edit the genomic DNA of and using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas)9 system. Using two prophages in as targets, large-fragment deletion mutants were achieved with rates of 100 or 20%.

pheS* as a counter-selectable marker for marker-free genetic manipulations in Bacillus anthracis.

Several genetic tools have been developed for use in Bacillus anthracis, but there is still a need for a more marker-free gene inactivation protocols. Thus, we report a method to generate unmarked mutations in B. anthracis.

[Construction of Lactobacillus rhamnosus GG particles surface display system].

To describe a novel particles surface display system which is consisted of gram-positive enhancer matrix (GEM) particles and anchor proteins for bacteria-like particles vaccines, we treated Lactobacillus rhamnosus GG bacteria with 10% heated-TCA for preparing GEM particles, and then identified the harvested GEM particles by electron microscopy, RT-PCR and SDS-PAGE. Meanwhile, Escherichia coli was induced to express hybrid proteins PA3-EGFP and P60-EGFP, and GEM particles were incubated with them. Then binding of anchor proteins were determined by Western blotting, transmission electron microscopy, fluorescence microscopy and spectrofluorometry.

inhibits the cleavage of TRAF1 a CagA-dependent mechanism.

Aim: To study the impact on cleavage of tumor necrosis factor receptor-associated factor 1 (TRAF1) regulated by ().

Methods: Cleavage of TRAF1 was detected by western blotting in the human gastric cancer cell line AGS following treatment with an apoptosis inducer. Cleavage of TRAF1 mediated by caspase was examined using specific caspase inhibitors.

Bacillus anthracis S-layer protein BslA binds to extracellular matrix by interacting with laminin.

Background: The Bacillus anthracis S-layer protein, BslA, plays a crucial role in mammalian infection. BslA is required to mediate adherence between host cells and vegetative forms of bacteria and this interaction promotes target organs adherence and blood-brain barrier (BBB) penetration in vivo. This study attempts to identify the potential eukaryotic ligand(s) for B.

The Upregulation of TRAF1 Induced by Helicobacter pylori Plays an Antiapoptotic Effect on the Infected Cells.

Background: Tumor necrosis factor receptor-associated factor 1 (TRAF1) is a member of the TRAF family and is dysregulated in diseases, such as atheroma, lymphoma, and solid tumors, but the role of TRAF1 in gastric cancer remains unknown. This study was aimed to investigate the role of TRAF1 in Helicobacter pylori (H. pylori)-related cell apoptosis and gastric carcinogenesis.

Production and cell surface display of recombinant anthrax protective antigen on the surface layer of attenuated Bacillus anthracis.

To investigate the surface display of the anthrax protective antigen (PA) on attenuated Bacillus anthracis, a recombinant B. anthracis strain, named AP429 was constructed by integrating into the chromosome a translational fusion harboring the DNA fragments encoding the cell wall-targeting domain of the S-layer protein EA1 and the anthrax PA. Crerecombinase action at the loxP sites excised the antibiotic marker.

[Recombinant expression, purification and adhesion function identify of Bacillus anthracis BslA(260 -652) protein].

Objective: To obtain the recombinant BslA(260-652) protein of Bacillus anthracis and prepare its antibody for the adhesion activity studies.

Methods: The fragment coding BslA(260-652) was cloned into pET28a(+) plasmid and induced to express recombinant protein in E. coli Rosetta (DE3) by Isopropyl beta-D-1-thiogalactopyranoside (IPTG).

Association of NOD1 and NOD2 genes polymorphisms with Helicobacter pylori related gastric cancer in a Chinese population.

Aim: To investigate the association between the tag single nucleotide polymorphisms (TagSNPs) of NOD1 and NOD2 and the risk of developing gastric cancer.

Methods: We conducted a hospital-based case-control study including 296 incident gastric cancer patients and 160 gastritis controls. Eight TagSNPs in the NOD1 and NOD2 genes were selected from the Hapmap database using the haploview software and genotyped by the Sequenom MassArray system.

[Development of a killed but metabolically active anthracis vaccine candidate strain].

Anthrax is a zoonosis caused by Bacillus anthracis, which seriously affects human health. In recent years, a special phenomenon is found that the metabolic active of a bacterium remains after it is killed. To development of a KBMA (killed but metabolically active) Bacillus anthracis vaccine candidate strain, a plasmid pMAD and a recombinase system Cre-loxP were used to knockout the uvrAB gene of B.

Identification of B-cell epitopes in urease B subunit of Helicobacter pylori bound by neutralizing antibodies.

To identify linear B-cell epitopes of urease B (UreB), a series of 19 partially overlapping fragments of the UreB gene were expressed. Three MAbs against UreB of Helicobacter pylori (H. pylori), A1H10, A3C10, and B3D9, were tested for their reactivity to the truncated proteins by Western blot and enzyme-linked immunosorbent assay (ELISA).

[Expression of snake venom thrombin-like enzyme calobin in Pichia pastoris].

Thrombin-like enzymes (TLEs) are studied widely because of their therapeutic potential in myocardial infarction and thrombotic diseases. We synthesized the DNA fragment encoding thrombin-like enzyme calobin from Agkistrodon caliginosus (Korean Viper) venom by fusion PCR and expressed it in Pichia pastoris. After induction by 0.

Removal of antibiotic resistance of live vaccine strain Escherichia coli MM-3 and evaluation of the immunogenicity of the new strain.

MM-3 was a live vaccine strain candidate for protecting neonatal piglets from diarrhea. Designed in the 1980s, a high degree of protection from colibacillosis was afforded to piglets in a challenge study and field trials. However MM-3 had a drawback of carrying the antibiotic resistance gene (chloramphenicol acetyltransferase gene, cat).

The role of thioredoxin and disulfide isomerase in the expression of the snake venom thrombin-like enzyme calobin in Escherichia coli BL21 (DE3).

Thrombin-like enzymes (TLEs) are studied widely because of their therapeutic potential in myocardial infarction and thrombotic diseases. But they are always produced in Escherichia coli BL21 (DE3) as inclusion bodies because they are single chain Cys-rich proteins. In this work, coexpressing of thioredoxin (TrxA) largely increased the solubility of calobin, one of the TLEs from korea viper Agkistrodon caliginosus, but soluble calobin-T had poor enzyme activity.

Antigen epitope of Helicobacter pylori vacuolating cytotoxin A.

Aim: To construct and select antigen epitopes of vacuolating cytotoxin A (VacA) for nontoxic VacA vaccine against Helicobacter pylori (H pylori ) infection.

Methods: Eleven VacA epitopes were predicted according to VacA antigenic bioinformatics. Three candidates of VacA epitope were constructed through different combined epitopes.