Molecularly specific detection of bacterial lipoteichoic acid for diagnosis of prosthetic joint infection of the bone

Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody（mAb） probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid（LTA）. Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immuno PET imaging in an in vivo mouse model of prosthetic joint infection（PJI）. In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography（PET） with [^（18）F]FDG and [^（18）F]Na F as well as X-ray computed tomography（CT）, before being evaluated with the zirconium-89-labeled antibody specific for LTA（[^（89）Zr]SAC55）.The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater（P 〈 0.05） uptake at S. aureus-infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [^（89）Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.

Insulin-mimetic compound hexaquis(benzylammonium) decavanadate is antilipolytic in human fat cells

AIM To assess in rodent and human adipocytes the antilipolytic capacity of hexaquis(benzylammonium) decavanadate(B6V10), previously shown to exert antidiabetic effects in rodent models, such as lowering free fatty acids(FFA) and glucose circulating levels.METHODS Adipose tissue(AT) samples were obtained after informed consent from overweight women undergoing plastic surgery. Comparison of the effects of B6V10 and reference antilipolytic agents(insulin,benzylamine,vanadate) on the lipolytic activity was performed on adipocytes freshly isolated from rat, mouse and human AT. Glycerol release was measured using colorimetric assay as an index of lipolytic activity. The influence of B6V10 and reference agents on glucose transport into human fat cells was determined using the radiolabelled 2-deoxyglucose uptake assay.RESULTS In all the species studied, B6V10 exhibited a dosedependent inhibition of adipocyte lipolysis when triglyceride breakdown was moderately enhanced by β-adrenergic receptor stimulation. B6V10 exerted on human adipocyte a maximal lipolysis inhibition of glycerol release that was stronger than that elicited by insulin. However, B6V10 did not inhibit basal and maximally stimulated lipolysis. When incubated at dose ≥ 10 μmol/L, B6V10 stimulated by twofold the glucose uptake in human fat cells, but-similarly to benzylamine-without reaching the maximal effect of insulin, while it reproduced one-half of the insulin-stimulation of lipogenesis in mouse fat cells. CONCLUSION B6V10 exerts insulin-like actions in adipocytes, including lipolysis inhibition and glucose transport activation. B6V10 may be useful in limiting lipotoxicity related to obesity and insulin resistance.

Transient and DNA-free in vivo CRISPR/Cas9 genome editing for flexible modeling of endometrial carcinogenesis

Dear Editor,The Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)and CRISPR-associated protein 9(Cas9)(CRISPR/Cas9)-mediated generation of somatically genetically engineered mouse models have emerged as a new approach for in vivo modeling of cancer[1].Here,we describe a novel DNA-free,easy,rapid,flexible,multiplexable,and robust method to model endometrial neoplasia by CRISPR/Cas9 ribonucleoprotein(RNP)electroporation into the uterus of mice.

The evolving species concepts used for yeasts:from phenotypes and genomes to speciation networks

Here we review how evolving species concepts have been applied to understand yeast diversity.Initially,a phenotypic species concept was utilized taking into consideration morphological aspects of colonies and cells,and growth profiles.Later the biological species concept was added,which applied data from mating experiments.Biophysical measurements of DNA similarity between isolates were an early measure that became more broadly applied with the advent of sequencing technology,leading to a sequence-based species concept using comparisons of parts of the ribosomal DNA.At present phylogenetic species concepts that employ sequence data of rDNA and other genes are universally applied in fungal taxonomy,including yeasts,because various studies revealed a relatively good correlation between the biological species concept and sequence divergence.The application of genome information is becoming increasingly common,and we strongly recommend the use of complete,rather than draft genomes to improve our understanding of species and their genome and genetic dynamics.Complete genomes allow in-depth comparisons on the evolvability of genomes and,consequently,of the species to which they belong.Hybridization seems a relatively common phenomenon and has been observed in all major fungal lineages that contain yeasts.Note that hybrids may greatly differ in their post-hybridization development.Future in-depth studies,initially using some model species or complexes may shift the traditional species concept as isolated clusters of genetically compatible isolates to a cohesive speciation network in which such clusters are interconnected by genetic processes,such as hybridization.

Correction to:The evolving species concepts used for yeasts:from phenotypes and genomes to speciation networks

The name of the second author was incorrectly captured in the initial online publication,and due to an error at the proofs stage,several proof corrections had been left undone.The original online article has been corrected.

Interleukin-1 beta induces the expression and production of stem cell factor by epithelial cells： crucial involvement of the PI-3K/mTOR pathway and HIF-1 transcription complex

Potential crosslinks between inflammation and leukaemia have been discussed for some time, but experimental evidence to support this dogma is scarce. In particular, it is important to understand the mechanisms responsible for potential upregulation of proto-oncogenic growth factor expressions by inflammatory mediators. Here, we investigated the ability of the highly inflammatory cytokine interleukin-1 beta （IL-1β） to induce the production of stem cell factor （SCF）, which is a major hematopoietic growth factor that controls the progression of acute myeloid leukaemia upon malignant transformation of haematopoietic myeloid cells. We found that human IL-1β induced the expression/secretion of SCF in MCF-7 human epithelial breast cancer cells and that this process depended on the hypoxia-inducible factor 1 （HIF-1） transcription complex. We also demonstrated a crucial role of the phosphatidylinositol-3 kinase （PI-3K）/mammalian target of rapamycin （mTOR） pathway in IL-1β-induced HIF-1α accumulation in MCF-7 cells. Importantly, mTOR was also found to play a role in IL-1β-induced SCF production. Furthermore, a tendency for a positive correlation of IL-1β and SCF levels in the plasma of healthy human donors was observed. Altogether, our results demonstrate that IL-1β, which normally bridges innate and adaptive immunity, induces the production of the major haematopoietic/proleukaemic growth factor SCF through the PI-3K/mTOR pathway and the HIF-1 transcription complex. These findings strongly suoDort a cross-talk between inflammation and acute mveloid leukaemia.

Controlling self-assembling and tumor cell-targeting of protein-only nanoparticles through modular protein engineering

Modular protein engineering is suited to recruit complex and multiple functionalities in single-chain polypeptides. Although still unexplored in a systematic way, it is anticipated that the positioning of functional domains would impact and refine these activities, including the ability to organize as supramolecular entities and to generate multifunctional protein materials. To explore this concept, we have repositioned functional segments in the modular protein T22-GFP-H6 and characterized the resulting alternative fusions. In T22-GFP-H6, the combination of T22 and H6 promotes selfassembling as regular nanoparticles and selective binding and internalization of this material in CXCR4-overexpressing tumor cells, making them appealing as vehicles for selective drug delivery. The results show that the pleiotropic activities are dramatically affected in module-swapped constructs, proving the need of a carboxy terminal positioning of H6 for protein self-assembling, and the accommodation of T22 at the amino terminus as a requisite for CXCR4^+ cell binding and internalization. Furthermore, the failure of self-assembling as regular oligomers reduces cellular penetrability of the fusions while keeping the specificity of the T22-CXCR4 interaction.All these data instruct how multifunctional nanoscale protein carriers can be designed for smart, protein-driven drug delivery, not only for the treatment of CXCR4^+ human neoplasias, but also for the development of anti-HIV drugs and other pathologies in which CXCR4 is a relevant homing marker.

Making Canonical Workflow Building Blocks Interoperable across Workflow Languages

We introduce the concept of Canonical Workflow Building Blocks(CWBB),a methodology of describing and wrapping computational tools,in order for them to be utilised in a reproducible manner from multiple workflow languages and execution platforms.The concept is implemented and demonstrated with the BioExcel Building Blocks library(BioBB),a collection of tool wrappers in the field of computational biomolecular simulation.Interoperability across different workflow languages is showcased through a protein Molecular Dynamics setup transversal workflow,built using this library and run with 5 different Workflow Manager Systems(WfMS).We argue such practice is a necessary requirement for FAIR Computational Workflows and an element of Canonical Workflow Frameworks for Research(CWFR)in order to improve widespread adoption and reuse of computational methods across workflow language barriers.

Trends in yeast diversity discovery

Yeasts,usually defined as unicellular fungi,occur in various fungal lineages.Hence,they are not a taxonomic unit,but rather represent a fungal lifestyle shared by several unrelated lineages.Although the discovery of new yeast species occurs at an increasing speed,at the current rate it will likely take hundreds of years,if ever,before they will all be documented.Many parts of the earth,including many threatened habitats,remain unsampled for yeasts and many others are only superficially studied.Cold habitats,such as glaciers,are home to a specific community of cold-adapted yeasts,and,hence,there is some urgency to study such environments at locations where they might disappear soon due to anthropogenic climate change.The same is true for yeast communities in various natural forests that are impacted by deforestation and forest conversion.Many countries of the so-called Global South have not been sampled for yeasts,despite their economic promise.However,extensive research activity in Asia,especially China,has yielded many taxonomic novelties.Comparative genomics stud-ies have demonstrated the presence of yeast species with a hybrid origin,many of them isolated from clinical or industrial environments.DNA-metabarcoding studies have demonstrated the prevalence,and in some cases dominance,of yeast species in soils and marine waters worldwide,including some surprising distributions,such as the unexpected and likely common presence of Malassezia yeasts in marine habitats.

Roles of the human microbiome in cancer

All external surfaces and internal mucosae of the human body are inhabited by rich microbial ecosystems,collectively known as the human microbiome.These microbial communities,formed by bacteria,archaea,fungi,protozoa and viruses interact among them and with our own physiology in ways that we are still far from understand.

Autoimmmune hepatitis

Autoimmune hepatitis(AIH)is a T-cell mediated,inflammatory liver disease affecting all ages and characterized by female preponderance,elevated serum transaminase and immunoglobulin G levels,positive circulating autoantibodies,and presence of interface hepatitis at liver histology.AIH type 1,affecting both adults and children,is defined by positive anti-nuclear and/or antismooth muscle antibodies,while type 2 AIH,affecting mostly children,is defined by positive anti-liver-kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody.While the autoantigens of type 2 AIH are well defined,being the cytochrome P4502D6(CYP2D6)and the formiminotransferase cyclodeaminase(FTCD),in type 1 AIH they remain to be identified.AIH-1 predisposition is conferred by possession of the MHC class II HLA DRB1*03 at all ages,while DRB1*04 predisposes to late onset disease;AIH-2 is associated with possession of DRB1*07 and DRB1*03.The majority of patients responds well to standard immunosuppressive treatment,based on steroid and azathioprine;second-and third-line drugs should be considered in case of intolerance or insufficient response.This review offers a comprehensive overview of pathophysiological and clinical aspects of AIH.