8,835 results match your criteria mediate bacterial

TRAIL produced by SAM-1-activated CD4 and CD8 subgroup T cells induces apoptosis in human tumor cells through upregulation of death receptors.

Toxicol Appl Pharmacol 2021 Jul 27:115656. Epub 2021 Jul 27.

Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China.

Bacterial superantigens potently activate conventional T-cells to induce massive cytokine production and mediate tumor cell death. To engineer superantigens for immunotherapy against tumors in clinic, we previously generated SAM-1, a staphylococcal enterotoxins C2 (SEC2) mutant, that exhibited significantly reduced toxicity but maintained the superantigen activity in animal models. This present study aimed to investigate whether SAM-1 activates T cells and induces apoptosis in human tumor cells. Read More

View Article and Full-Text PDF

An enzymatic activation of formaldehyde for nucleotide methylation.

Nat Commun 2021 07 27;12(1):4542. Epub 2021 Jul 27.

Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège De France, Université Pierre et Marie Curie, Paris, France.

Folate enzyme cofactors and their derivatives have the unique ability to provide a single carbon unit at different oxidation levels for the de novo synthesis of amino-acids, purines, or thymidylate, an essential DNA nucleotide. How these cofactors mediate methylene transfer is not fully settled yet, particularly with regard to how the methylene is transferred to the methylene acceptor. Here, we uncovered that the bacterial thymidylate synthase ThyX, which relies on both folate and flavin for activity, can also use a formaldehyde-shunt to directly synthesize thymidylate. Read More

View Article and Full-Text PDF

The signaling role of extracellular ATP in co-culture of Shiraia sp. S9 and Pseudomonas fulva SB1 for enhancing hypocrellin A production.

Microb Cell Fact 2021 Jul 23;20(1):144. Epub 2021 Jul 23.

College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, China.

Background: Adenosine 5'-triphosphate (ATP) plays both a central role as an intracellular energy source, and a crucial extracellular signaling role in diverse physiological processes of animals and plants. However, there are less reports concerning the signaling role of microbial extracellular ATP (eATP). Hypocrellins are effective anticancer photodynamic therapy (PDT) agents from bambusicolous Shiraia fungi. Read More

View Article and Full-Text PDF

Methylprednisolone Induces Extracellular Trap Formation and Enhances Bactericidal Effect of Canine Neutrophils.

Int J Mol Sci 2021 Jul 20;22(14). Epub 2021 Jul 20.

Department of Biochemistry, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany.

Methylprednisolone is a glucocorticoid and can negatively influence immune defense mechanisms. During bacterial infections in the dog, neutrophils infiltrate infected tissue and mediate antimicrobial effects with different mechanisms such as phagocytosis and neutrophil extracellular trap (NET) formation. Here, we investigated the influence of methylprednisolone on canine NET formation and neutrophil killing efficiency of Gram positive and Gram negative bacteria. Read More

View Article and Full-Text PDF

escapes lysosomal degradation through inactivation of Rab31 by IpaH4.5.

J Med Microbiol 2021 Jul;70(7)

Beijing Institute of Biotechnology, Academy of Military Medical Sciences (AMMS), Beijing, PR China.

is an intracellular bacterial pathogen that utilizes a type III secretion apparatus to inject effector proteins into host cells. The T3SS effector IpaH4.5 is important for the virulence of . Read More

View Article and Full-Text PDF

Exploiting pilus-mediated bacteria-host interactions for health benefits.

Mol Aspects Med 2021 Jul 19:100998. Epub 2021 Jul 19.

Laboratory of Structural Microbiology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad, 121001, India. Electronic address:

Surface pili (or fimbriae) are an important but conspicuous adaptation of several genera and species of Gram-negative and Gram-positive bacteria. These long and non-flagellar multi-subunit adhesins mediate the initial contact that a bacterium has with a host or environment, and thus have come to be regarded as a key colonization factor for virulence activity in pathogens or niche adaptation in commensals. Pili in pathogenic bacteria are well recognized for their roles in the adhesion to host cells, colonization of tissues, and establishment of infection. Read More

View Article and Full-Text PDF

The Polymeric Matrix Composition of Biofilms Modulate Resistance to Silver Nanoparticles Prepared by Hydrothermal Synthesis.

ACS Appl Mater Interfaces 2021 Jul 21. Epub 2021 Jul 21.

CREPEC, Department of Chemical Engineering, Polytechnique Montréal, Montréal, Québec H3T1J4, Canada.

Biofilms represent the dominant microbial lifestyle in nature. These complex microbial communities in which bacteria are embedded in a self-produced protective polymeric extracellular matrix, display an enhanced resistance to antimicrobials and thus represent a major health challenge. Although nanoparticles have proven to be effective against bacteria, the interactions between nanoparticles and the polymeric biofilm matrix are still unclear. Read More

View Article and Full-Text PDF

Nitric Oxide System and Bronchial Epithelium: More Than a Barrier.

Front Physiol 2021 30;12:687381. Epub 2021 Jun 30.

Department of Pharmacology, Faculty of Medicine, University of Valencia, Valencia, Spain.

Airway epithelium forms a physical barrier that protects the lung from the entrance of inhaled allergens, irritants, or microorganisms. This epithelial structure is maintained by tight junctions, adherens junctions and desmosomes that prevent the diffusion of soluble mediators or proteins between apical and basolateral cell surfaces. This apical junctional complex also participates in several signaling pathways involved in gene expression, cell proliferation and cell differentiation. Read More

View Article and Full-Text PDF

Discovery of fibrillar adhesins across bacterial species.

BMC Genomics 2021 Jul 18;22(1):550. Epub 2021 Jul 18.

European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, CB10 1SD, UK.

Background: Fibrillar adhesins are long multidomain proteins that form filamentous structures at the cell surface of bacteria. They are an important yet understudied class of proteins composed of adhesive and stalk domains that mediate interactions of bacteria with their environment. This study aims to characterize fibrillar adhesins in a wide range of bacterial phyla and to identify new fibrillar adhesin-like proteins to improve our understanding of host-bacteria interactions. Read More

View Article and Full-Text PDF

Group 3 innate lymphoid cells mediate host defense against attaching and effacing pathogens.

Curr Opin Microbiol 2021 Jul 15;63:83-91. Epub 2021 Jul 15.

Innate Immunity Unit, Institut Pasteur, Inserm U1223, Paris, France. Electronic address:

Group 3 innate lymphoid cells (ILC3) are innate effector cells that have essential roles in lymphoid organogenesis and maintenance of tissue homeostasis under steady-state and pathogenic conditions. ILC3 also promote immune defense, notably during bacterial breach of epithelial barriers, including those caused by attaching and effacing (A/E) pathogens for which Citrobacter rodentium infection in mice is a relevant pre-clinical model. Through their ability to sustain interactions with tissue-resident immune cells, epithelial cells, neurons or stromal cells, ILC3 constitute a key orchestrator that maintains the intestinal barrier. Read More

View Article and Full-Text PDF

Differential Enhancement of Neutrophil Phagocytosis by Anti-Bactericidal/Permeability-Increasing Protein Antibodies.

J Immunol 2021 08 16;207(3):777-783. Epub 2021 Jul 16.

Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH; and

Bactericidal/permeability-increasing protein (BPI) plays a major role in innate immunity through the ability of the N-terminal domain (NTD) to bind LPS, mediate cytotoxicity, and block LPS-induced inflammation. The C-terminal domain mediates phagocytosis of bacteria bound to the NTD. These two domains are linked by a surface-exposed loop at amino acids 231-249 for human BPI, known as the "hinge region. Read More

View Article and Full-Text PDF

Quorum-Sensing Signals from Epibiont Mediate the Induction of Novel Microviridins in the Mat-Forming Cyanobacterial Genus .

mSphere 2021 Jul 14:e0056221. Epub 2021 Jul 14.

Laboratory of Algal Biotechnology, Institute of Microbiology of the Czech Academy of Sciences-Center Algatech, Trebon, Czech Republic.

The regulation of the production of oligopeptides is essential in understanding their ecological role in complex microbial communities, including harmful cyanobacterial blooms. The role of chemical communication between the cyanobacterium and the microbial community harbored as epibionts within its phycosphere is at an initial stage of research, and little is understood about its specificity. Here, we present insight into the role of a bacterial epibiont in regulating the production of novel microviridins isolated from , an ecologically important cyanobacterial genus. Read More

View Article and Full-Text PDF

Protein Transfer through an F Plasmid-Encoded Type IV Secretion System Suppresses the Mating-Induced SOS Response.

mBio 2021 Jul 13:e0162921. Epub 2021 Jul 13.

Department of Microbiology and Molecular Genetics, McGovern Medical School, Houston, Texas, USA.

Bacterial type IV secretion systems (T4SSs) mediate the conjugative transfer of mobile genetic elements (MGEs) and their cargoes of antibiotic resistance and virulence genes. Here, we report that the pED208-encoded T4SS (Tra) translocates not only this F plasmid but several plasmid-encoded proteins, including ParA, ParB1, single-stranded DNA-binding protein SSB, ParB2, PsiB, and PsiA, to recipient cells. Conjugative protein translocation through the Tra T4SS required engagement of the pED208 relaxosome with the TraD substrate receptor or coupling protein. Read More

View Article and Full-Text PDF

Protein acetyltransferases mediate bacterial adaptation to a diverse environment.

J Bacteriol 2021 Jul 12:JB0023121. Epub 2021 Jul 12.

School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, India 751024.

Protein lysine acetylation is a conserved post-translational modification that modulates several cellular processes. Protein acetylation and its physiological implications are well understood in eukaryotes; however, its role is emerging in bacteria. Lysine acetylation in bacteria is fine-tuned by the concerted action of lysine acetyltransferases (KATs), protein deacetylases (KDACs), metabolic intermediates- acetyl-coenzyme A (Ac-CoA) and acetyl phosphate (AcP). Read More

View Article and Full-Text PDF

Pannexin 1 as a driver of inflammation and ischemia-reperfusion injury.

Purinergic Signal 2021 Jul 12. Epub 2021 Jul 12.

Robert M. Berne Cardiovascular Research Center, School of Medicine, University of Virginia, PO Box 801394, Charlottesville, VA, 22908, USA.

Pannexin 1 (Panx1) is a ubiquitously expressed protein forming large conductance channels that are central to many distinct inflammation and injury responses. There is accumulating evidence showing ATP released from Panx1 channels, as well as metabolites, provide effective paracrine and autocrine signaling molecules that regulate different elements of the injury response. As channels with a broad range of permselectivity, Panx1 channels mediate the secretion and uptake of multiple solutes, ranging from calcium to bacterial derived molecules. Read More

View Article and Full-Text PDF

A rice LRR receptor like protein associates with its adaptor kinase OsSOBIR1 to mediate plant immunity against viral infection.

Plant Biotechnol J 2021 Jul 12. Epub 2021 Jul 12.

State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, 315211, China.

Plants sense pathogen attacks using a variety of receptors at the cell surface. The LRR receptor like proteins (RLP) and receptor like kinases (RLK) are widely reported to participate in plant defense against bacterial and fungal pathogen invasion. However, the role of RLP and RLK in plant antiviral defense has rarely been reported. Read More

View Article and Full-Text PDF

Clinically Relevant Bacterial Outer Membrane Models for Antibiotic Screening Applications.

ACS Infect Dis 2021 Jul 6. Epub 2021 Jul 6.

Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York United States.

Antibiotic resistance is a growing global health concern that has been increasing in prevalence over the past few decades. In Gram-negative bacteria, the outer membrane is an additional barrier through which antibiotics must traverse to kill the bacterium. In addition, outer membrane features and properties, like membrane surface charge, lipopolysaccharide (LPS) length, and membrane porins, can be altered in response to antibiotics and therefore, further mediate resistance. Read More

View Article and Full-Text PDF

Shades of grey: host phenotype dependent effect of urbanization on the bacterial microbiome of a wild mammal.

Anim Microbiome 2021 Jul 5;3(1):46. Epub 2021 Jul 5.

Department of Integrative Biology, College of Biological Sciences, University of Guelph, Guelph, N1G 2W1, Canada.

Background: Host-associated microbiota are integral to the ecology of their host and may help wildlife species cope with rapid environmental change. Urbanization is a globally replicated form of severe environmental change which we can leverage to better understand wildlife microbiomes. Does the colonization of separate cities result in parallel changes in the intestinal microbiome of wildlife, and if so, does within-city habitat heterogeneity matter? Using 16S rRNA gene amplicon sequencing, we quantified the effect of urbanization (across three cities) on the microbiome of eastern grey squirrels (Sciurus carolinensis). Read More

View Article and Full-Text PDF

Mechanisms for Chromosome Segregation in Bacteria.

Front Microbiol 2021 16;12:685687. Epub 2021 Jun 16.

Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.

The process of DNA segregation, the redistribution of newly replicated genomic material to daughter cells, is a crucial step in the life cycle of all living systems. Here, we review DNA segregation in bacteria which evolved a variety of mechanisms for partitioning newly replicated DNA. Bacterial species such as and contain pushing and pulling mechanisms that exert forces and directionality to mediate the moving of newly synthesized chromosomes to the bacterial poles. Read More

View Article and Full-Text PDF

Xanthomonas effector XopR hijacks host actin cytoskeleton via complex coacervation.

Nat Commun 2021 07 1;12(1):4064. Epub 2021 Jul 1.

School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.

The intrinsically disordered region (IDR) is a preserved signature of phytobacterial type III effectors (T3Es). The T3E IDR is thought to mediate unfolding during translocation into the host cell and to avoid host defense by sequence diversification. Here, we demonstrate a mechanism of host subversion via the T3E IDR. Read More

View Article and Full-Text PDF

Evidence for the Role of Mitochondrial DNA Release in the Inflammatory Response in Neurological Disorders.

Int J Mol Sci 2021 Jun 29;22(13). Epub 2021 Jun 29.

Department of Chemistry and Biology, Hope College, Holland, MI 49423, USA.

Mitochondria are regarded as the metabolic centers of cells and are integral in many other cell processes, including the immune response. Each mitochondrion contains numerous copies of mitochondrial DNA (mtDNA), a small, circular, and bacterial-like DNA. In response to cellular damage or stress, mtDNA can be released from the mitochondrion and trigger immune and inflammatory responses. Read More

View Article and Full-Text PDF

Extracellular Vesicles and Host-Pathogen Interactions: A Review of Inter-Kingdom Signaling by Small Noncoding RNA.

Bruce A Stanton

Genes (Basel) 2021 Jun 30;12(7). Epub 2021 Jun 30.

Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.

The focus of this brief review is to describe the role of noncoding regulatory RNAs, including short RNAs (sRNA), transfer RNA (tRNA) fragments and microRNAs (miRNA) secreted in extracellular vesicles (EVs), in inter-kingdom communication between bacteria and mammalian (human) host cells. Bacteria secrete vesicles that contain noncoding regulatory RNAs, and recent studies have shown that the bacterial vesicles fuse with and deliver regulatory RNAs to host cells, and similar to eukaryotic miRNAs, regulatory RNAs modulate the host immune response to infection. Recent studies have also demonstrated that mammalian cells secrete EVs containing miRNAs that regulate the gut microbiome, biofilm formation and the bacterial response to antibiotics. Read More

View Article and Full-Text PDF

Lymphocytes and Trogocytosis-Mediated Signaling.

Cells 2021 Jun 12;10(6). Epub 2021 Jun 12.

Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.

Trogocytosis is the intercellular transfer of membrane and membrane-associated molecules. This underappreciated process has been described in a variety of biological settings including neuronal remodeling, fertilization, viral and bacterial spread, and cancer, but has been most widely studied in cells of the immune system. Trogocytosis is performed by multiple immune cell types, including basophils, macrophages, dendritic cells, neutrophils, natural killer cells, B cells, γδ T cells, and CD4 and CD8 αβ T cells. Read More

View Article and Full-Text PDF

Effects of the Traditional Mediterranean Diet in Patients with Otitis Media with Effusion.

Nutrients 2021 Jun 24;13(7). Epub 2021 Jun 24.

Child and Adolescent Clinic "La Palma", C/Palma 17, bajo A, 13001 Ciudad Real, Spain.

Introduction: Otitis media with effusion (OME) is common in pediatric primary care consultations. Its etiology is multifactorial, although it has been proven that inflammation factors mediate and that immunity is in a phase of relative immaturity. The objective of this study was to assess the effects of the Traditional Mediterranean Diet (TMD) modulating inflammation and immunity in patients diagnosed with OME. Read More

View Article and Full-Text PDF

TLR2 Regulates Mast Cell IL-6 and IL-13 Production During Infection.

Front Immunol 2021 14;12:650779. Epub 2021 Jun 14.

Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (ENCB-IPN), Mexico City, Mexico.

(L.m) is efficiently controlled by several cells of the innate immunity, including the Mast Cell (MC). MC is activated by L. Read More

View Article and Full-Text PDF

Microbiota regulate social behaviour via stress response neurons in the brain.

Nature 2021 Jul 30;595(7867):409-414. Epub 2021 Jun 30.

Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.

Social interactions among animals mediate essential behaviours, including mating, nurturing, and defence. The gut microbiota contribute to social activity in mice, but the gut-brain connections that regulate this complex behaviour and its underlying neural basis are unclear. Here we show that the microbiome modulates neuronal activity in specific brain regions of male mice to regulate canonical stress responses and social behaviours. Read More

View Article and Full-Text PDF

Genome analysis of Streptomyces sp. UH6 revealed the presence of potential chitinolytic machinery crucial for chitosan production.

Environ Microbiol Rep 2021 Jun 30. Epub 2021 Jun 30.

Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana, India.

Chitosan and its derivatives have numerous applications in wastewater treatment as bio-coagulants, flocculants and bio-adsorbents against both particulate and dissolved pollutants. Chitinolytic bacteria secrete an array of enzymes, which play crucial role in chitin to chitosan conversion. Consequently, there is a growing demand for identification and characterization of novel bacterial isolates with potential implications in chitosan production. Read More

View Article and Full-Text PDF

Phages carry interbacterial weapons encoded by biosynthetic gene clusters.

Curr Biol 2021 Jun 16. Epub 2021 Jun 16.

Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads bldg. 221, DK-2800 Kgs Lyngby, Denmark. Electronic address:

Bacteria produce diverse specialized metabolites that mediate ecological interactions and serve as a rich source of industrially relevant natural products. Biosynthetic pathways for these metabolites are encoded by organized groups of genes called biosynthetic gene clusters (BGCs). Understanding the natural function and distribution of BGCs provides insight into the mechanisms through which microorganisms interact and compete. Read More

View Article and Full-Text PDF

DegP Initiates Regulated Processing of Filamentous Hemagglutinin in Bordetella bronchiseptica.

mBio 2021 06 29;12(3):e0146521. Epub 2021 Jun 29.

Department of Microbiology and Immunology, School of Medicine, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA.

Filamentous hemagglutinin (FhaB) is a critical virulence factor for both Bordetella pertussis, the causal agent of whooping cough, and the closely related species Bordetella bronchiseptica. FhaB is an adhesin, suppresses inflammatory cytokine production, and protects against phagocytic cell clearance during infection. Regulated degradation of the FhaB C-terminal prodomain is required to establish a persistent infection in mice. Read More

View Article and Full-Text PDF

Effectors of the Stenotrophomonas maltophilia Type IV Secretion System Mediate Killing of Clinical Isolates of Pseudomonas aeruginosa.

mBio 2021 06 29;12(3):e0150221. Epub 2021 Jun 29.

Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA.

Previously, we documented that Stenotrophomonas maltophilia encodes a type IV secretion system (T4SS) that allows the organism to kill, in contact-dependent fashion, heterologous bacteria, including wild-type Pseudomonas aeruginosa. Bioinformatic screens based largely on the presence of both a C-terminal consensus sequence and an adjacent gene encoding a cognate immunity protein identified 13 potential antibacterial effectors, most of which were highly conserved among sequenced strains of S. maltophilia. Read More

View Article and Full-Text PDF