Salmonella manipulates macrophage migration via SteC-mediated myosin light chain activation to penetrate the gut-vascular barrier.

The intestinal pathogen Salmonella enterica rapidly enters the bloodstream after the invasion of intestinal epithelial cells, but how Salmonella breaks through the gut-vascular barrier is largely unknown. Here, we report that Salmonella enters the bloodstream through intestinal CX3CR1+ macrophages during early infection. Mechanistically, Salmonella induces the migration/invasion properties of macrophages in a manner dependent on host cell actin and on the pathogen effector SteC. SteC recruits host myosin light chain protein Myl12a and phosphorylates its Ser19 and Thr20 residues. Myl12a phosphorylation results in actin rearrangement, and enhanced migration and invasion of macrophages. SteC is able to utilize a wide range of NTPs other than ATP to phosphorylate Myl12a. We further solved the crystal structure of SteC, which suggests an atypical dimerization-mediated catalytic mechanism. Finally, in vivo data show that SteC-mediated cytoskeleton manipulation is crucial for Salmonella breaching the gut vascular barrier and spreading to target organs.

L-Rhamnose Enhances the Immunogenicity of Melanoma-Associated Antigen A3 for Stimulating Antitumor Immune Responses.

Vaccines based on melanoma-associated antigens (MAGEs) present a promising strategy for tumor immunotherapy, albeit with weak immunogenicity. In this study, the xenoantigen L-rhamnose (Rha) was chemically conjugated with truncated MAGE-A3 (tMAGE-A3) to generate Rha-tMAGE-A3. The product showed good antigenicity with anti-Rha antibodies purified from human serum. FITC-labeled Rha-tMAGE-A3 was detected in THP-1 human macrophage cells via the anti-Rha antibody-dependent antigen uptake process. Furthermore, peripheral blood mononuclear cells (PBMCs) stimulated with Rha-tMAGE-A3 in the presence of anti-Rha antibodies showed better cytotoxicity toward A375 human melanoma cells surfaced by MAGE-A3 antigen compared to PBMCs stimulated with tMAGE-A3. All data reveal that linking of Rha epitopes to MAGE enhances the immunogenicity of MAGE by harnessing the immune effector functions of human naturally existing anti-Rha antibodies. Rha epitopes could become immunogenicity enhancers of tumor associated antigens in the development of tumor immunotherapies.

Production of human blood group B antigen epitope conjugated protein in Escherichia coli and utilization of the adsorption blood group B antibody.

BACKGROUND: In the process of ABO-incompatible (ABOi) organ transplantation, removal of anti-A and/or B antibodies from blood plasma is a promising method to overcome hyperacute rejection and allograft loss caused by the immune response between anti-A and/or B antibodies and the A and/or B antigens in the recipient. Although there are commercial columns to do this work, the application is still limited because of the high production cost. RESULTS: In this study, the PglB glycosylation pathway from Campylobacter jejuni was exploited to produce glycoprotein conjugated with Escherichia coli O86:B7 O-antigen, which bears the blood group B antigen epitope to absorb blood group B antibody in blood. The titers of blood group B antibody were reduced to a safe level without changing the clotting function of plasma after glycoprotein absorption of B antibodies in the plasma. CONCLUSIONS: We developed a feasible strategy for the specific adsorption/removal of blood group antibodies. This method will be useful in ABOi organ transplantation and universal blood transfusion.

[Regulation of the O-antigen polysaccharide chain length by Wzz- a review ].

The O-antigen of Gram-negative bacterium plays an important role in the signal identification, adhesion, immune evasion and other processes. There are three O-antigen polysaccharides biosynthesis mechanisms according to the type of the flippase that is involved. The Wzy-dependent mechanism is more commonly seen. In Wzy-dependent mechanism, the wzz gene is involved in regulating the length of O-antigen polysaccharide chain which can affect antigenicity of the pathogen and immune response of the host. Based on the crystal structure of Wzz (regulator of the O- antigen polysaccharides length) , different length of O-antigen chain can be obtained through molecular modification of the gene wzz. Conjugating O-antigen or its mutants of a pathogen to a carrier protein could help to develop a vaccine that have both a good target specificity and a strong immunogenicity. Therefore, it is important to understand the function, structure and mechanism of Wzz for the development and production of glycoconjugates vaccine.

A c-di-GMP binding effector STM0435 modulates flagellar motility and pathogenicity in Salmonella.

Flagella play a crucial role in the invasion process of Salmonella and function as a significant antigen that triggers host pyroptosis. Regulation of flagellar biogenesis is essential for both pathogenicity and immune escape of Salmonella. We identified the conserved and unknown function protein STM0435 as a new flagellar regulator. The ∆stm0435 strain exhibited higher pathogenicity in both cellular and animal infection experiments than the wild-type Salmonella. Proteomic and transcriptomic analyses demonstrated dramatic increases in almost all flagellar genes in the ∆stm0435 strain compared to wild-type Salmonella. In a surface plasmon resonance assay, purified STM0435 protein-bound c-di-GMP had an affinity of ~8.383 µM. The crystal structures of apo-STM0435 and STM0435&c-di-GMP complex were determined. Structural analysis revealed that R33, R137, and D138 of STM0435 were essential for c-di-GMP binding. A Salmonella with STM1987 (GGDEF protein) or STM4264 (EAL protein) overexpression exhibits completely different motility behaviours, indicating that the binding of c-di-GMP to STM0435 promotes its inhibitory effect on Salmonella flagellar biogenesis.

Pancreatic diffuse large B-cell lymphoma: a case report and literature review.

Primary pancreatic lymphoma is an extremely rare malignant tumor that accounts for 1% and 0.5% of all extranodal malignant lymphomas and pancreatic tumors, respectively. The clinical and radiographic characteristics of primary pancreatic lymphoma are non-specific, and it is often misdiagnosed as pancreatic cancer or pancreatic tuberculosis, delaying treatment. The most common histological subtype of primary pancreatic lymphoma is diffuse large B-cell lymphoma. Herein, we report a case of a 48-year-old female patient who was hospitalized for complaints of lower back pain, jaundice, dark brown urine, nausea, and ascites. Radiological evaluation revealed a pancreatic head mass that was diagnosed as diffuse large B-cell lymphoma following ultrasound-guided percutaneous fine-needle biopsy. During hospitalization, the patient's jaundice worsened, and percutaneous transhepatic drainage was performed. However, hemorrhagic ascites and disorders of consciousness occurred after surgery, and the patient died due to multiple organ failure. Considering the outcome of this case, we reviewed the existing relevant literature on primary pancreatic lymphoma to better understand the disease to facilitate timely diagnosis and initiation of treatment.

Hematochezia caused by tandospirone in a patient with major depressive disorder and anxious distress: a case report.

Background: Major depressive disorder (MDD) with anxious distress is a relatively common condition that is often associated with a poor treatment response. In order to enhance the effectiveness of MDD treatment, 5-HT1A agonists like tandospirone are often prescribed in conjunction with antidepressants. While it is known that antidepressants can increase the risk of bleeding, whether tandospirone poses a similar risk remains uncertain. Case presentation: We presented the case of a 55-year-old Chinese woman diagnosed with MDD and anxious distress. After receiving various types of antidepressants, she experienced hematochezia following the administration of tandospirone, sertraline, and agomelatine. The occurrence of hematochezia ceased after tandospirone was discontinued. The patient was subsequently discharged with a treatment regime consisting of sertraline and agomelatine. During the 1-month follow-up, she reported no hematochezia. Conclusion: Tandospirone may potentially increase the risk of hematochezia in patients with MDD and anxious distress.

Coactivator-associated arginine methyltransferase 1: A versatile player in cell differentiation and development.

Protein arginine methylation is a common post-translational modification involved in the regulation of various cellular functions. Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine methyltransferase that asymmetrically dimethylates histone H3 and non-histone proteins to regulate gene transcription. CARM1 has been found to play important roles in cell differentiation and development, cell cycle progression, autophagy, metabolism, pre-mRNA splicing and transportation, and DNA replication. In this review, we describe the molecular characteristics of CARM1 and summarize its roles in the regulation of cell differentiation and development in mammals.

Clostridioides difficile cd2775 Encodes a Unique Mannosyl-1-Phosphotransferase for Polysaccharide II Biosynthesis.

Clostridioides difficile (C. difficile) is the leading cause of antibiotic-induced bacterial colitis and life-threatening diarrhea worldwide. The commonly existing anionic polysaccharide II (PSII) is responsible for protein anchoring involved in colonization, and the gene cd2775 located in its biosynthesis gene cluster is essential for bacterial growth. Herein, we demonstrated that cd2775 encodes a novel mannosyl-1-phosphotransferase (ManPT) responsible for the phosphorylation of PSII. Unlike typical mannosyltransferases, CD2775 transfers mannose-α1-phosphate instead of mannose from guanosine 5'-diphospho-d-mannose to disaccharide acceptors, forming a unique mannose-α1-phosphate-6-glucose linkage. The enzyme was overexpressed in E. coli and purified for biochemical characterization and substrate specificity study. It is found that CD2775 possesses a strict acceptor specificity toward Glc-ß1,3-GalNAc-diphospho-lipids but extreme promiscuity toward various sugar donors. This is the first report of a ManPT in all living systems. Given its essentiality in C. difficile growth, CD2775 can be a promising target for therapeutics development.

RecET Direct Cloning of Polysaccharide Gene Cluster from Gram-Negative Bacteria.

RecET direct cloning enables obtaining a large DNA region from genome. Here we describe its applications in cloning of polysaccharide gene cluster from gram-negative bacteria. Rapid and exact cloning of polysaccharide gene cluster can be achieved by this method.

Direct Cloning of Bacterial Surface Polysaccharide Gene Cluster for One-Step Production of Glycoconjugate Vaccine.

Bacterial pathogen infections are fast-growing public health threats and worldwide problems. Glycoconjugate vaccines are among the most effective means in combating such infections. Recent advances in bacterial protein glycan coupling technology (PGCT) have revolutionized the production of glycoconjugate vaccines and drawn enormous attention from both researchers and pharmaceutical companies. Cloning of bacterial surface polysaccharide gene cluster is a prerequisite for the application of PGCT. In this study, we applied the RecET direct cloning strategy for rapid and efficient cloning of O-antigen polysaccharide gene clusters from Escherichia coli serotypes O25b, O26, and O55 in a high-fidelity manner. Then, these gene clusters were applied in PGCT to produce corresponding glycoconjugates. Subsequent immunological studies verified the abilities of glycoconjugate vaccine candidates O25-maltose-binding protein (MBP), O26-MBP, and O55-MBP to generate serotype-specific antibodies and confer protection against E. coli infections. The combination of RecET direct cloning and PGCT makes the rapid production of glycoconjugate vaccines against fast-expanding bacterial pathogens possible.

Efficacy of cognitive behavioral therapy in children and adolescents with insomnia: a systematic review and meta-analysis.

Insomnia is highly prevalent in children and adolescents. However, the efficacy of cognitive behavioral therapy for insomnia (CBT-i) in children and adolescents remains controversial. Therefore, this systematic review and meta-analysis aimed to assess the efficacy of CBT-i in children and adolescents. We conducted a search of PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, CINAHL, and PsycINFO to select primary studies evaluating CBT-i in children and adolescents that were primarily diagnosed through standardized diagnostic criteria. The primary outcomes of the meta-analysis included sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE%). Six randomized controlled trials and four open-label trials met all inclusion criteria. A total of 464 participants (ranging from 5-19 years of age) were included. Based on the results from sleep logs, a significant pooled effect size was observed for SOL and SE%. However, no significant pooled effect size was found for WASO or TST. Results from actigraphy were consistent with the sleep logs. A significant pooled effect size was observed for SOL and SE%, and no significant pooled effect size was found for WASO or TST. CBT-i might be effective in the treatment of children and adolescents with insomnia.

Peptide adjacent to glycosylation sites impacts immunogenicity of glycoconjugate vaccine.

Glycoconjugate vaccine is composed of polysaccharides (PSs) covalently linked with carrier protein. Glycosylation site selection, as a significant factor leading to heterogeneities of glycoconjugate structure, draws more and more attentions for its impact on the immunogenicity of glycoconjugate vaccine. To elucidate the relationship between glycosylation connectivity and immunogenicity of glycoconjugate vaccine, in this study, anti-E. coli O157:H7 glycoconjugate O-PS-MBP with defined connectivity, and three selected peptide segments GS1, GS2, GS3 derived from O-PS-MBP was synthesized. Immunogenicity results showed that only peptides adjacent to the glycosylation sites (GS1 and GS2) promoted the generation of PS-specific IgG antibodies and contributed to PS-specific IgG subclass distribution. Furthermore, GS1 and GS2 had significant priming effect for eliciting PS-specific IgG antibodies. These results indicated that different locations of glycosylation sites could lead to diverse presentation of peptides and glycopeptides to APCs and influence the immunogenicity of glycoconjugate vaccine, which extend the current understanding of mechanism for adaptive immune system activation by glycoconjugate vaccine, and have implications for rational glycoconjugate vaccine design.

Repetitive transcranial magnetic stimulation (rTMS) augmentation of selective serotonin reuptake inhibitors (SSRIs) for SSRI-resistant obsessive-compulsive disorder (OCD): a meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVE: Randomized controlled trials (RCTs) on repetitive transcranial magnetic stimulation (rTMS) as augmentation of selective serotonin reuptake inhibitors (SSRIs) for SSRI-resistant obsessive-compulsive disorder (OCD) have yielded conflicting results. Therefore, this meta-analysis was conducted to assess the efficacy of this strategy for SSRI-resistant OCD. METHODS: Scientific and medical databases, including international databases (PubMed, MEDLINE, EMBASE, CCTR, Web of Science, PsycINFO), two Chinese databases (CBM-disc, CNKI), and relevant websites dated up to July 2014, were searched for RCTs on this strategy for treating OCD. Mantel-Haenszel random-effects model was used. Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score, response rates and drop-out rates were evaluated. RESULTS: Data were obtained from nine RCTs consisting of 290 subjects. Active rTMS was an effective augmentation strategy in treating SSRI-resistant OCD with a pooled WMD of 3.89 (95% CI = [1.27, 6.50]) for reducing Y-BOCS score and a pooled odds ratio (OR) of 2.65 (95% CI = [1.36, 5.17] for response rates. No significant differences in drop-out rates were found. No publication bias was detected. CONCLUSION: The pooled examination demonstrated that this strategy seems to be efficacious and acceptable for treating SSRI-resistant OCD. As the number of RCTs included here was limited, further large-scale multi-center RCTs are required to validate our conclusions.

A one-pot approach to bio-synthesize globotriose and its derivatives from simpler substrates.

Globotriose is involved in numerous pathogenic processes and drug development strategies. Recent studies have demonstrated that globotriosylceramide could be used in colon cancer therapy and as a crucial indicator for susceptibility to HIV-1 infection. Therefore, the cost-effective and facile approaches for large-scale production of globotiose as potential drugs are highly required. Here, a multi-enzyme one-pot system containing a galactokinase (SpGalK, E.C.2.7.1.6), a UDP-glucose pyrophosphorylase (SpGalU, E.C.2.7.7.9), a α-1,4-galactosyltransferase (LgtC, E.C. 2.4.1.44) and a commercial inorganic pyrophosphatase (PPase, EC 3.6.1.1) was designed to achieve globotriose on preparative scales. This method exploits a cheaper initial substrate, galactose, for donor UDP-galactose production. More importantly, the substrate specificity of SpGalK and SpGalU is highly promiscuous and various UDP-galactose derivatives obtained could be used as the donor substrates for LgtC. This pointcut of rapid preparation of globotriose derivatives is proposed for the first time. Finally, three globotriose analogs were achieved by this one-pot multi-enzyme system in our study.

Glycoconjugate vaccine containing Escherichia coli O157:H7 O-antigen linked with maltose-binding protein elicits humoral and cellular responses.

Glycoconjugate is one of the most efficacious and safest vaccines against bacterial pathogens. Previous studies of glycoconjugates against pathogen E. coli O157:H7 focused more on the humoral responses they elicited. However, little was known about their cellular responses. In this study, we exploited a novel approach based on bacterial protein N-linked glycosylation system to produce glycoconjugate containing Escherichia coli O157:H7 O-antigen linked with maltose-binding protein and examined its humoral and cellular responses in BALB/c mice. The transfer of E. coli O157:H7 O-antigen to MBP was confirmed by western blot and MALDI-TOF MS. Mice injected with glycoconjugate O-Ag-MBP elicited serum bactericidal antibodies including anti-E. coli O157:H7 O-antigen IgG and IgM. Interestingly, O-Ag-MBP also stimulated the secretion of anti-E. coli O157:H7 O-antigen IgA in intestine. In addition, O-Ag-MBP stimulated cellular responses by recruiting Th1-biased CD4+ T cells, CD8+ T cells. Meanwhile, O-Ag-MBP induced the upregulation of Th1-related IFN-γ and downregulation of Th2-related IL-4, and the upregulation of IFN-γ was stimulated by MBP in a dose-dependent manner. MBP showed TLR4 agonist-like properties to activate Th1 cells as carrier protein of O-Ag-MBP. Thus, glycoconjugate vaccine E. coli O157:H7-specific O-Ag-MBP produced by bacterial protein N-linked glycosylation system was able to elicit both humoral and Th1-biased cellular responses.

Efficacy of cognitive behavioral therapy in children and adolescents with insomnia: a systematic review and meta-analysis

Insomnia is highly prevalent in children and adolescents. However, the efficacy of cognitive behavioral therapy for insomnia (CBT-i) in children and adolescents remains controversial. Therefore, this systematic review and meta-analysis aimed to assess the efficacy of CBT-i in children and adolescents. We conducted a search of PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, CINAHL, and PsycINFO to select primary studies evaluating CBT-i in children and adolescents that were primarily diagnosed through standardized diagnostic criteria. The primary outcomes of the meta-analysis included sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE%). Six randomized controlled trials and four open-label trials met all inclusion criteria. A total of 464 participants (ranging from 5-19 years of age) were included. Based on the results from sleep logs, a significant pooled effect size was observed for SOL and SE%. However, no significant pooled effect size was found for WASO or TST. Results from actigraphy were consistent with the sleep logs. A significant pooled effect size was observed for SOL and SE%, and no significant pooled effect size was found for WASO or TST. CBT-i might be effective in the treatment of children and adolescents with insomnia.

Executive functioning deficits and childhood trauma in juvenile violent offenders in China.

A large body of evidence indicates that violent offenders have executive functioning deficits. However, previous studies have not considered childhood trauma, which is likely to influence the executive functioning of violent offenders. The aim of the present study was to compare the difference of executive functioning among juvenile violent offenders, with non-violent offenders and normal controls, and then to analyse whether executive functioning was affected independently of childhood trauma. In addition to using a battery of tests assessing executive functioning including the Intra/Extradimensional Shift Test(IED), the Stockings of Cambridge Test (SOC), and the Spatial Working Memory Test (SWM) from the Cambridge Automated Neuropsychological Testing Battery (CANTAB), the short form of the Chinese Revision of the Wechsler Adult Intelligence Scale (WAIS-RC) and Childhood Trauma Questionnaire-28 item Short Form (CTQ) were also used among 107 violent offenders, 107 non-violent offenders and 107 normal controls. Our results showed that both offender groups obtained significantly lower estimated Intelligence Quotient (IQ) scores and experienced more childhood trauma than did normal controls. Violent offenders showed impaired executive functioning on tasks of attention set-shifting, working memory and planning. Finally, spatial working memory (SWM) deficits, particularly SWM strategy scores, may be associated with childhood trauma.