Search results for "LB"
showing 10 items of 5653 documents
Complex Regulatory Networks Governing Production of the Glycopeptide A40926
2018
Glycopeptides (GPAs) are an important class of antibiotics, with vancomycin and teicoplanin being used in the last 40 years as drugs of last resort to treat infections caused by Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus. A few new GPAs have since reached the market. One of them is dalbavancin, a derivative of A40926 produced by the actinomycete Nonomuraea sp. ATCC 39727, recently classified as N. gerenzanensis. This review summarizes what we currently know on the multilevel regulatory processes governing production of the glycopeptide A40926 and the different approaches used to increase antibiotic yields. Some nutrients, e.g., valine, l-glutamine and mal…
The role of dalbavancin for Gram positive infections in the COVID-19 era: state of the art and future perspectives
2021
INTRODUCTION: The COVID-19 pandemic has dramatically challenged the national health systems worldwide in the last months. Dalbavancin is a novel antibiotic with a long plasmatic half-life and simplified weekly administration regimens, thus representing a promising option for the outpatient treatment of Gram-positive infections and the early discharge of hospitalized patients. Dalbavancin is approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). Many preliminary data seem to support its use in other indications, such as osteomyelitis, prosthetic joint infections, and infective endocarditis. AREAS COVERED: A search in the literature using validated keyword…
Fast-Growing Alveolar Echinococcosis Following Lung Transplantation
2020
International audience; Alveolar echinococcosis is a rare but life-threatening infection caused by the parasiteEchinococcus multilocularis. Its natural history is characterized by a slow parasitic growth over several years. Increased incidence and shorter development delay have been reported in immune-compromised patients. We report the reactivation of aborted lesions within 12 months of lung transplantation leading to a fast-growing aggressive hepatic lesion. Timely identification of alveolar echninococcosis allowed prompt albendazole treatment and radical surgery leading to a favorable outcome 42 months after transplantation. However, close clinical, serological and radiological monitorin…
Systemic Candidiasis and TLR2 Agonist Exposure Impact the Antifungal Response of Hematopoietic Stem and Progenitor Cells.
2018
We have previously demonstrated that Candida albicans induces differentiation of hematopoietic stem and progenitor cells (HSPCs) toward the myeloid lineage both in vitro and in vivo in a TLR2- and Dectin-1-dependent manner, giving rise to functional macrophages. In this work, we used an ex vivo model to investigate the functional consequences for macrophages derived from HSPCs in vivo-exposed to Pam3CSK4 (a TLR2 agonist) or C. albicans infection. Short in vivo treatment of mice with Pam3CSK4 results in a tolerized phenotype of ex vivo HSPC-derived macrophages, whereas an extended Pam3CSK4 treatment confers a trained phenotype. Early during candidiasis, HSPCs give rise to macrophages trained…
Comprehensive identification of Vibrio vulnificus genes required for growth in human serum.
2018
ABSTRACT Vibrio vulnificus can be a highly invasive pathogen capable of spreading from an infection site to the bloodstream, causing sepsis and death. To survive and proliferate in blood, the pathogen requires mechanisms to overcome the innate immune defenses and metabolic limitations of this host niche. We created a high-density transposon mutant library in YJ016, a strain representative of the most virulent V. vulnificus lineage (or phylogroup) and used transposon insertion sequencing (TIS) screens to identify loci that enable the pathogen to survive and proliferate in human serum. Initially, genes underrepresented for insertions were used to estimate the V. vulnificus essential gene set;…
Neural Stem Cell Regulation by Adhesion Molecules Within the Subependymal Niche
2019
In the mammalian adult brain, neural stem cells persist in neurogenic niches. The subependymal zone is the most prolific neurogenic niche in adult rodents, where residing stem cells generate large numbers of immature neurons that migrate into the olfactory bulb, where they differentiate into different types of interneurons. Subependymal neural stem cells derive from embryonic radial glia and retain some of their features like apico-basal polarity, with apical processes piercing the ependymal layer, and a basal process contacting blood vessels, constituting an epithelial niche. Conservation of the cytoarchitecture of the niche is of crucial importance for the maintenance of stem cells and fo…
Antibody-mediated blockade of JMJD6 interaction with collagen I exerts antifibrotic and antimetastatic activities
2017
JMJD6 is known to localize in the nucleus, exerting histone arginine demethylase and lysyl hydroxylase activities. A novel localization of JMJD6 in the extracellular matrix, resulting from its secretion as a soluble protein, was unveiled by a new anti-JMJD6 mAb called P4E11, which was developed to identify new targets in the stroma. Recombinant JMJD6 binds with collagen type I (Coll-I), and distinct JMJD6 peptides interfere with collagen fibrillogenesis, collagen-fibronectin interaction, and adhesion of human tumor cells to the collagen substrate. P4E11 and collagen binding to JMJD6 are mutually exclusive because the amino acid sequences of JMJD6 necessary for the interaction with Coll-I ar…
The Mouse Cytomegalovirus Gene m42 Targets Surface Expression of the Protein Tyrosine Phosphatase CD45 in Infected Macrophages
2016
The receptor-like protein tyrosine phosphatase CD45 is expressed on the surface of cells of hematopoietic origin and has a pivotal role for the function of these cells in the immune response. Here we report that following infection of macrophages with mouse cytomegalovirus (MCMV) the cell surface expression of CD45 is drastically diminished. Screening of a set of MCMV deletion mutants allowed us to identify the viral gene m42 of being responsible for CD45 down-modulation. Moreover, expression of m42 independent of viral infection upon retroviral transduction of the RAW264.7 macrophage cell line led to comparable regulation of CD45 expression. In immunocompetent mice infected with an m42 del…
Murine cytomegalovirus (CMV) infection via the intranasal route offers a robust model of immunity upon mucosal CMV infection
2016
Cytomegalovirus (CMV) is a ubiquitous virus, causing the most common congenital infection in humans, yet a vaccine against this virus is not available. Experimental studies of immunity against CMV in animal models of infection, such as the infection of mice with mouse CMV (MCMV), have relied mainly on parenteral infection protocols, although the virus naturally transmits by mucosal routes via body fluids. To characterize the biology of infections by mucosal routes, we compared the kinetics of virus replication, latent viral load and CD8 T-cell responses in lymphoid organs upon experimental intranasal (targeting the respiratory tract) and intragastric (targeting the digestive tract) infectio…
Mesenchymal Transition of High-Grade Breast Carcinomas Depends on Extracellular Matrix Control of Myeloid Suppressor Cell Activity
2016
SummaryThe extracellular matrix (ECM) contributes to the biological and clinical heterogeneity of breast cancer, and different prognostic groups can be identified according to specific ECM signatures. In high-grade, but not low-grade, tumors, an ECM signature characterized by high SPARC expression (ECM3) identifies tumors with increased epithelial-to-mesenchymal transition (EMT), reduced treatment response, and poor prognosis. To better understand how this ECM3 signature is contributing to tumorigenesis, we expressed SPARC in isogenic cell lines and found that SPARC overexpression in tumor cells reduces their growth rate and induces EMT. SPARC expression also results in the formation of a h…