Paracoccidioides brasiliensis, a thermal dimorphic fungal pathogen, produces a melanin-like pigment in vitro and in vivo. We investigated the involvement of carbohydrates and monoclonal antibody to CD18, on phagocytosis inhibition, involving macrophage receptors and the resistance of melanized fungal cells to chemically generated nitric oxide (NO), reactive oxygen species (ROS), hypochlorite and H2O2. Our results demonstrate that melanized yeast cells were more resistant than nonmelanized yeast cells to chemically generated NO, ROS, hypochlorite and H2O2, in vitro. Phagocytosis of melanized yeast cells was virtually abolished when mannan, N-acetyl glucosamine and anti-CD18 antibody were added together in this system. Intratracheal infection of BALB/c mice, with melanized yeast cells, resulted in higher lung colony forming units, when compared to nonmelanized yeast cells. Therefore, melanin is a virulence factor of P. brasiliensis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1590/s0074-02762009000400019 | DOI Listing |
iScience
January 2025
Laboratory of Antibody Discovery and Accelerated Protein Therapeutics, Center for Infectious Diseases, Houston Methodist Research Institute and Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, TX, USA.
T7 RNA polymerase (RNAP) has enabled orthogonal control of gene expression and recombinant protein production across diverse prokaryotic host chassis organisms for decades. However, the absence of 5' methyl guanosine caps on T7 RNAP-derived transcripts has severely limited its utility and widespread adoption in eukaryotic systems. To address this shortcoming, we evolved a fusion enzyme combining T7 RNAP with the single subunit capping enzyme from African swine fever virus using .
View Article and Find Full Text PDFiScience
January 2025
Department of Biology, Graduate School of Science, Chiba University, Chiba 263-8522, Japan.
The regulation of cellular metabolism is crucial for cell survival, with Sch9 in serving a key role as a substrate of TORC1. Sch9 localizes to the vacuolar membrane through binding to PI(3,5)P, which is necessary for TORC1-dependent phosphorylation. This study demonstrates that cytosolic pH regulates Sch9 localization.
View Article and Find Full Text PDFAnal Chem
January 2025
The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
CD28 is a costimulatory receptor that provides the second signal necessary for T-cell activation and is associated with diseases, including rheumatoid arthritis, asthma, and cancer. Targeting CD28 is crucial for both functional bioanalysis and therapeutic development. Molecular probes, particularly fluorescent probes, can enhance our understanding of CD28's cellular roles.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Immunobiology, University of Lausanne, Epalinges, Switzerland.
Fluorescence recovery after photobleaching (FRAP) can be employed to investigate membrane lipid mixing of vacuoles in live budding yeast cells and distinguish the fused, hemi-fused or non-fused states of these organelles under physiological conditions. Here, we describe a protocol for labeling the outer and inner leaflets of vacuoles in live cells that allow to detect hemifusion intermediates and, thus, identify components necessary for fusion pore opening.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.
Cell-free in vitro assays offer several advantages for elucidating molecular mechanisms underlying various biological processes. Here, we describe a simple and quantitative in vitro assay using isolated yeast microsomes to measure homotypic ER membrane fusion. In this assay, membrane fusion between ER microsomes is monitored by reconstitution of luciferase activity from split luciferase fragments.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!