Sialic acid plays a pivotal role in licensing transition from the intestinal lumen to a mucosal adherent niche.

Enteric bacterial pathogens pose significant threats to human health; however, the mechanisms by which they infect the mammalian gut in the face of daunting host defenses and an established microbiota remain poorly defined. For the attaching and effacing (A/E) bacterial family member and murine pathogen , its virulence strategy likely involves metabolic adaptation to the host's intestinal luminal environment, as a necessary precursor to reach and infect the mucosal surface. Suspecting this adaptation involved the intestinal mucus layer, we found that was able to catabolize sialic acid, a monosaccharide derived from mucins, and utilize it as its sole carbon source for growth.

Successful treatment of a kidney transplant patient with COVID-19 and late-onset Pneumocystis jirovecii pneumonia.

Background: Solid transplant patients are susceptible to Pneumocystis jirovecii pneumonia (PJP). While the vast majority of PJP cases occur within the first 6 months after transplantation, very few PJP cases are seen beyond 1 year post-transplantation (late-onset PJP). PJP and coronavirus disease 2019 (COVID-19, caused by infection with SARS-CoV-2) share quite a few common clinical manifestations and imaging findings, making the diagnosis of PJP often underappreciated during the current COVID-19 pandemic.

Vasoactive intestinal peptide promotes host defense against enteric pathogens by modulating the recruitment of group 3 innate lymphoid cells.

Group 3 innate lymphoid cells (ILC3s) control the formation of intestinal lymphoid tissues and play key roles in intestinal defense. They express neuropeptide vasoactive intestinal peptide (VIP) receptor 2 (VPAC2), through which VIP modulates their function, but whether VIP exerts other effects on ILC3 remains unclear. We show that VIP promotes ILC3 recruitment to the intestine through VPAC1 independent of the microbiota or adaptive immunity.

Harnessing Big Data to Optimize an Algorithm for Rapid Diagnosis of Pulmonary Tuberculosis in a Real-World Setting.

Background: The prompt diagnosis of pulmonary tuberculosis (PTB) remains a challenge in clinical practice. The present study aimed to optimize an algorithm for rapid diagnosis of PTB in a real-world setting.

Methods: 28,171 adult inpatients suspected of having PTB in China were retrospectively analyzed.

Ulcerative Colitis-associated pathobionts potentiate colitis in susceptible hosts.

Ulcerative colitis (UC) is a chronic inflammatory condition linked to intestinal microbial dysbiosis, including the expansion of strains related to extra-intestinal pathogenic . These "pathobionts" exhibit pathogenic properties, but their potential to promote UC is unclear due to the lack of relevant animal models. Here, we established a mouse model using a representative UC pathobiont strain (p19A), and mice lacking single immunoglobulin and toll-interleukin 1 receptor domain (SIGIRR), a deficiency increasing susceptibility to gut infections.

Direct Clinical Evidence Recommending the Use of Proteinase K or Dithiothreitol to Pretreat Sputum for Detection of SARS-CoV-2.

One of the primary tools for diagnosing COVID-19 is the nucleic acid-based real-time reverse transcriptase-polymerase chain reaction (RT-PCR) test performed on respiratory specimens. The detection rate of SARS-CoV-2 in lower respiratory specimens (such as sputum) is higher than that for upper respiratory specimens (such as nasal and pharyngeal swabs). However, sputum specimens are usually quite viscous, requiring a homogenization process prior to nucleic acid (NA) extraction for RT-PCR.

Bacterial quorum-sensing signal IQS induces host cell apoptosis by targeting POT1-p53 signalling pathway.

Pseudomonas aeruginosa, an opportunistic life-threatening human bacterial pathogen, employs quorum-sensing (QS) signal molecules to modulate virulence gene expression. 2-(2-hydroxyphenyl)-thiazole-4-carbaldehyde (IQS) is a recently identified QS signal that integrates the canonical lasR-type QS of P. aeruginosa and host phosphate stress response to fine-tune its virulence production for a successful infection.

The Type III Translocon Protein EseC Inhibits Biofilm Formation by Sequestering EseE.

The type III secretion system (T3SS) is one of the most important virulence factors of the fish pathogen It contains three translocon proteins, EseB, EseC, and EseD, required for translocation of effector proteins into host cells. We have previously shown that EseB forms filamentous appendages on the surface of , and these filamentous structures mediate bacterial cell-cell interactions promoting autoaggregation and biofilm formation. In the present study, we show that EseC, but not EseD, inhibits the autoaggregation and biofilm formation of At 18 h postsubculture, a Δ strain developed strong autoaggregation and mature biofilm formation, accompanied by enhanced formation of EseB filamentous appendages.

Regulation of Type III Secretion of Translocon and Effector Proteins by the EsaB/EsaL/EsaM Complex in Edwardsiella tarda.

The type III secretion system (T3SS) plays a crucial role in the pathogenesis of many Gram-negative bacteria, including , an important fish pathogen. Within the T3SS, there are three proteins (EsaB/EsaL/EsaM) that are homologous to proteins present in many other bacteria, including SpiC/SsaL/SsaM in , SepD/SepL/CesL in enteropathogenic (EPEC) and enterohemorrhagic (EHEC), and YscB/YopN/SycN in EsaL was found to interact with both EsaB and EsaM within the bacterial cell, as revealed by a coimmunoprecipitation assay. Moreover, EsaM is required for EsaB stability, and the two proteins interact with each other.

EseE of Edwardsiella tarda Augments Secretion of Translocon Protein EseC and Expression of the escC-eseE Operon.

Edwardsiella tarda is an important Gram-negative pathogen that employs a type III secretion system (T3SS) to deliver effectors into host cells to facilitate bacterial survival and replication. These effectors are translocated into host cells through a translocon complex composed of three secreted proteins, namely, EseB, EseC, and EseD. The secretion of EseB and EseD requires a chaperone protein called EscC, whereas the secretion of EseC requires the chaperone EscA.

NFATc2 mediates epigenetic modification of dendritic cell cytokine and chemokine responses to dectin-1 stimulation.

The transcription factor NFATc2 regulates dendritic cell (DC) responses to microbial stimulation through the C-type lectin receptor dectin-1. But the genetic targets of NFATc2 and their effects on DC function remain largely unknown. Therefore we used ChIP-seq to conduct genome-wide mapping of NFATc2 target sites in dectin-1-activated DCs.

Pleiotropic functions for transcription factor zscan10.

The transcription factor Zscan10 had been attributed a role as a pluripotency factor in embryonic stem cells based on its interaction with Oct4 and Sox2 in in vitro assays. Here we suggest a potential role of Zscan10 in controlling progenitor cell populations in vivo. Mice homozygous for a Zscan10 mutation exhibit reduced weight, mild hypoplasia in the spleen, heart and long bones and phenocopy an eye malformation previously described for Sox2 hypomorphs.

[Study on phosphorus adsorption characteristic of sediments in an ecological ditch].

Sediments properties and phosphorus (P) adsorption capacities were compared among the samples of 0-5 cm and 5-15 cm layers from the ecological ditch vegetated with Cenetlla asiatica, Sparganium stoloniferum and a natural agricultural ditch with weeds. The results showed the 0-5 cm sediment vegetated with Cenetlla asiatica had higher concentrations of oxalate extracted Fe, Al and P than those vegetated with Sparganium stoloniferum or weeds. The parameters calculated from the Freudlich and Langmiur isotherms showed the equilibrium phosphate concentration (EPC0) ranged from 0.

Coassembly of REST and its cofactors at sites of gene repression in embryonic stem cells.

The differentiation of pluripotent embryonic stem cells is regulated by networks of activating and repressing transcription factors that orchestrate determinate patterns of gene expression. With the recent mapping of target sites for many transcription factors, it has been a conundrum that so few of the genes directly targeted by these factors are transcriptionally responsive to the binding of that factor. To address this, we generated genome-wide maps of the transcriptional repressor REST and five of its corepressors in mouse embryonic stem cells.

[Expression of interleukin-12p40 and interferon-gamma in local lesions of human oral lichen planus].

Objective: To investigate the significance of cytokine interleukin-12p40 (IL-12p40) and interferon-gamma (IFN-gamma) in tissues formation and development of human oral lichen planus (OLP).

Methods: The tissues of 11 cases of normal oral epithelium and 43 cases of OLP were investigated for the expression of IL-12p40 and IFN-gamma proteins by using Envision two-step immunohistochemistry. The correlations between the expressions of these two cytokines, and their clinical and pathological significance in OLP were analyzed.

EseG, an effector of the type III secretion system of Edwardsiella tarda, triggers microtubule destabilization.

Edwardsiella tarda is a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and both gastrointestinal and extraintestinal infections in humans. A type III secretion system (T3SS) was recently shown to contribute to pathogenesis, since deletions of various T3SS genes increased the 50% lethal dose (LD(50)) by about 1 log unit in the blue gourami infection model. In this study, we report EseG as the first identified effector protein of T3SS.

Sequestosome-1/p62 is the key intracellular target of innate defense regulator peptide.

Innate defense regulator-1 (IDR-1) is a synthetic peptide with no antimicrobial activity that enhances microbial infection control while suppressing inflammation. Previously, the effects of IDR-1 were postulated to impact several regulatory pathways including mitogen-activated protein kinase (MAPK) p38 and CCAAT-enhancer-binding protein, but how this was mediated was unknown. Using a combined stable isotope labeling by amino acids in cell culture-proteomics methodology, we identified the cytoplasmic scaffold protein p62 as the molecular target of IDR-1.

Zfp206, Oct4, and Sox2 are integrated components of a transcriptional regulatory network in embryonic stem cells.

Zfp206 (recently renamed Zscan10) encodes a zinc finger transcription factor specifically expressed in human and mouse embryonic stem cells (ESC). It has been shown that Zfp206 is required to maintain ESC in an undifferentiated, pluripotent state. Presented here are data showing that Zfp206 works together with two other transcription factors, Oct4 and Sox2, which are also essential regulators of ESC pluripotency.

Mapping of the chaperone AcrH binding regions of translocators AopB and AopD and characterization of oligomeric and metastable AcrH-AopB-AopD complexes in the type III secretion system of Aeromonas hydrophila.

In the type III secretion system (T3SS) of Aeromonas hydrophila, AcrH acts as a chaperone for translocators AopB and AopD. AcrH forms a stable 1:1 monomeric complex with AopD, whereas the 1:1 AcrH-AopB complex exists mainly as a metastable oligomeric form and only in minor amounts as a stable monomeric form. Limited protease digestion shows that these complexes contain highly exposed regions, thus allowing mapping of intact functional chaperone binding regions of AopB and AopD.

The caspase-1 inflammasome: a pilot of innate immune responses.

The inflammasome is a large multiprotein complex whose assembly leads to the activation of caspase-1, which promotes the maturation of proinflammatory cytokines interleukin-1beta (IL-1beta) and IL-18. Proteins encoded by the nucleotide-binding domain and leucine-rich repeat (NLR) containing gene family form the central components of inflammasomes and act as intracellular sensors to detect cytosolic microbial components and "danger" signals (such as ATP and toxins). The inflammasome not only plays a pivotal role in innate immune responses toward pathogens but also mediates the activity of aluminum adjuvants.

Structure of AscE and induced burial regions in AscE and AscG upon formation of the chaperone needle-subunit complex of type III secretion system in Aeromonas hydrophila.

In the type III secretion system (T3SS) of Aeromonas hydrophila, the putative needle complex subunit AscF requires both putative chaperones AscE and AscG for formation of a ternary complex to avoid premature assembly. Here we report the crystal structure of AscE at 2.7 A resolution and the mapping of buried regions of AscE, AscG, and AscF in the AscEG and AscEFG complexes using limited protease digestion.

Aeromonas hydrophila AH-3 AexT is an ADP-ribosylating toxin secreted through the type III secretion system.

We cloned and sequenced an ADP-ribosylating toxin (AexT) from a mesophilic Aeromonas hydrophila strain AH-3 with a type III secretion system (T3SS). This toxin only showed homology, in genes and proteins, with the first half of A. salmonicida AexT.

Characterization of extracellular proteins produced by Aeromonas hydrophila AH-1.

Aeromonas hydrophila is a ubiquitous Gram-negative bacterium which can cause motile aeromonad septicemia in both fish and humans. A. hydrophila secretes many extracellular proteins associated with pathogenicity and environmental adaptability.