Plasticity of cell death pathways ensures GSDMD activation during Yersinia pseudotuberculosis infection.

Macrophages express pattern recognition and cytokine receptors that mediate proinflammatory signal transduction pathways to combat microbial infection. To retaliate against such responses, pathogenic microorganisms have evolved multiple strategies to impede innate immune signaling. Recent studies demonstrated that YopJ suppression of TAK1 signaling during Yersinia pseudotuberculosis infection promotes the assembly of a RIPK1-dependent death-inducing complex that enables caspase-8 to directly cleave and activate gasdermin D (GSDMD).

Direct vagus nerve stimulation: A new tool to control allergic airway inflammation through α7 nicotinic acetylcholine receptor.

Background And Purpose: Asthma is characterized by airway inflammation, mucus hypersecretion, and airway hyperresponsiveness. The use of nicotinic agents to mimic the cholinergic anti-inflammatory pathway (CAP) controls experimental asthma. Yet, the effects of vagus nerve stimulation (VNS)-induced CAP on allergic inflammation remain unknown.

MFSD7c functions as a transporter of choline at the blood-brain barrier.

Mutations in the orphan transporter MFSD7c (also known as Flvcr2), are linked to Fowler syndrome. Here, we used Mfsd7c knockout (Mfsd7c) mice and cell-based assays to reveal that MFSD7c is a choline transporter at the blood-brain barrier (BBB). We performed comprehensive metabolomics analysis and detected differential changes of metabolites in the brains and livers of Mfsd7cembryos.

iPS-cell-derived microglia promote brain organoid maturation via cholesterol transfer.

Microglia are specialized brain-resident macrophages that arise from primitive macrophages colonizing the embryonic brain. Microglia contribute to multiple aspects of brain development, but their precise roles in the early human brain remain poorly understood owing to limited access to relevant tissues. The generation of brain organoids from human induced pluripotent stem cells recapitulates some key features of human embryonic brain development.

cccDNA-Targeted Drug Screen Reveals a Class of Antihistamines as Suppressors of HBV Genome Levels.

Chronic infection with hepatitis B virus (HBV) is incurable, as the current therapeutics cannot eliminate its persistent genomic material, cccDNA. Screening systems for cccDNA-targeting therapeutics are unavailable, as low copies of cccDNA in vitro complicate detection. To address this, cccDNA copies were massively increased to levels detectable via automated plate readers.

Characterisation of a human antibody that potentially links cytomegalovirus infection with systemic lupus erythematosus.

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that has been linked with the development of systemic lupus erythematosus (SLE). Thus far, molecular mimicry has been implicated as the principal mechanism that explains this association. In this study, we characterise a potential alternative process whereby HCMV contributes to SLE.

Studies on B Cells in the Fruit-Eating Black Flying Fox (.

The ability of bats to act as reservoir for viruses that are highly pathogenic to humans suggests unique properties and functional characteristics of their immune system. However, the lack of bat specific reagents, in particular antibodies, has limited our knowledge of bat's immunity. Here, we report a panel of cross-reactive antibodies against MHC-II, NK1.

Prohibitin plays a critical role in Enterovirus 71 neuropathogenesis.

A close relative of poliovirus, enterovirus 71 (EV71) is regarded as an important neurotropic virus of serious public health concern. EV71 causes Hand, Foot and Mouth Disease and has been associated with neurological complications in young children. Our limited understanding of the mechanisms involved in its neuropathogenesis has hampered the development of effective therapeutic options.

Drosophila cells use nanotube-like structures to transfer dsRNA and RNAi machinery between cells.

Tunnelling nanotubes and cytonemes function as highways for the transport of organelles, cytosolic and membrane-bound molecules, and pathogens between cells. During viral infection in the model organism Drosophila melanogaster, a systemic RNAi antiviral response is established presumably through the transport of a silencing signal from one cell to another via an unknown mechanism. Because of their role in cell-cell communication, we investigated whether nanotube-like structures could be a mediator of the silencing signal.

Chikungunya Virus Replication in Salivary Glands of the Mosquito Aedes albopictus.

Chikungunya virus (CHIKV) is an emerging arbovirus transmitted to humans by mosquitoes such as Aedes albopictus. To be transmitted, CHIKV must replicate in the mosquito midgut, then disseminate in the hemocele and infect the salivary glands before being released in saliva. We have developed a standardized protocol to visualize viral particles in the mosquito salivary glands using transmission electron microscopy.

Paenibacillus faecis sp. nov., isolated from human faeces.

A spore-forming, rod-shaped Gram-strain-positive bacterium, strain 656.84T, was isolated from human faeces in 1984. It contained anteiso-C15 : 0 as the major cellular fatty acid, meso-diaminopimelic acid was found in the cell wall peptidoglycan, the polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and aminophospholipids as the major components, and the predominant menaquinone was MK-7.

Emergence and transmission of arbovirus evolutionary intermediates with epidemic potential.

The high replication and mutation rates of RNA viruses can result in the emergence of new epidemic variants. Thus, the ability to follow host-specific evolutionary trajectories of viruses is essential to predict and prevent epidemics. By studying the spatial and temporal evolution of chikungunya virus during natural transmission between mosquitoes and mammals, we have identified viral evolutionary intermediates prior to emergence.

Real-time observation of listeria monocytogenes-phagocyte interactions in living zebrafish larvae.

The zebrafish, Danio rerio, has become a popular vertebrate model for the study of infections, mainly because of its excellent optical accessibility at the embryonic and larval stages, when the innate immune system is already effective. We have thus tested the susceptibility of zebrafish larvae to the human pathogen Listeria monocytogenes, a gram-positive, facultative, intracellular bacterium that is known to survive and multiply in professional phagocytes and that causes fatal meningitis and abortions. Intravenous injection of early zebrafish larvae resulted in a progressive and ultimately fatal infection.

Diaphanous-related formins are required for invadopodia formation and invasion of breast tumor cells.

Proteolytic degradation of the extracellular matrix by metastatic tumor cells is initiated by the formation of invadopodia, i.e., actin-driven filopodia-like membrane protrusions endowed with matrix-degradative activity.

Uropathogenic Escherichia coli AL511 requires flagellum to enter renal collecting duct cells.

Escherichia coli is the leading cause of urinary tract infections, but the mechanisms governing renal colonization by this bacterium remain poorly understood. We investigated the ability of 13 E. coli strains isolated from the urine of patients with pyelonephritis and cystitis and normal stools to invade collecting duct cells, which constitute the first epithelium encountered by bacteria ascending from the bladder.

Regulatory role of UvrY in adaptation of Photorhabdus luminescens growth inside the insect.

We report global expression profiling of a uvrY-deficient mutant of Photorhabdus luminescens. We found that the regulator moiety of the two-component regulatory system BarA/UvrY regulated more than 500 target genes coding for functions involved in the synthesis of major compartments and metabolic pathways of the cell. This regulation appeared to be in part indirect as UvrY affected the expression of several regulators.

Pleiotropic role of quorum-sensing autoinducer 2 in Photorhabdus luminescens.

Bacterial virulence is an integrative process that may involve quorum sensing. In this work, we compared by global expression profiling the wild-type entomopathogenic Photorhabdus luminescens subsp. laumondii TT01 to a luxS-deficient mutant unable to synthesize the type 2 quorum-sensing inducer AI-2.

Assembly and role of pili in group B streptococci.

Streptococcus agalactiae[group B streptococcus (GBS)] is the leading cause of neonatal pneumonia, sepsis and meningitis. An in silico genome analysis indicated that GBS strain NEM316 encodes five putative sortases, including the major class A sortase enzyme and four class C sortases. The genes encoding the class C sortases are tandemly arranged in two different loci, srtC1-C2 and srtC3-C4, with a similar genetic organization and are thought to be involved in pilus biosynthesis.

Isolation from canned foods of a novel Thermoanaerobacter species phylogenetically related to Thermoanaerobacter mathranii (Larsen 1997): emendation of the species description and proposal of Thermoanaerobacter mathranii subsp. Alimentarius subsp. Nov.

Several anaerobic, thermophilic, Gram-positive bacteria were isolated from dairy products and canned meats. While some isolates were identified as Thermoanaerobacter thermohydrosulfuricus, comparisons of 16S rDNA genes indicated that others were phylogenetically closely related to Thermoanaerobacter mathranii, and more distantly related to Thermoanaerobacter thermocopriae and Thermoanaerobacter italicus. Biochemical characteristics, phylogenetic analysis, G+C content, and DNA-DNA hybridization experiments demonstrated that the strains AIP 504.

Ultrastructural analysis of the interactions between Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica and human tracheal epithelial cells.

Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica are respiratory pathogens that colonize the respiratory tract of their host after adhesion to the respiratory epithelium. Presently, the intracellular fate of these bacteria in human tracheal epithelial cells was compared by use of transmission electron microscopy. The three species, even when cytotoxic, were taken-up by epithelial cells.

Oribacterium sinus gen. nov., sp. nov., within the family 'Lachnospiraceae' (phylum Firmicutes).

A hitherto unknown anaerobic bacillus isolated from sinus pus in a young child (strain AIP 354.02T) was characterized by using phenotypic and genotypic methods. 16S rRNA gene sequence analysis indicated that this strain was phylogenetically affiliated with several sequences of cloned 16S rRNA gene inserts previously deposited in the public databases.