Monitoring <Emphasis Type="Italic">ALS1</Emphasis> and <Emphasis Type="Italic">ALS3</Emphasis> Gene Expression During In Vitro <Emphasis Type="Italic">Candida albicans</Emphasis> Biofilm Formation Under Continuous Flow Conditions

ALS1 and ALS3 encode cell-surface associated glycoproteins that are considered to be important for Candida albicans biofilm formation. The main goal of the present study was to monitor ALS1 and ALS3 gene expression during C. albicans biofilm formation (on silicone) under continuous flow conditions, using the Centers for Disease Control biofilm reactor (CDC reactor). For ALS1, we found few changes in gene expression until later stages of biofilm formation (72 and 96 h) when this gene appeared to be downregulated relative to the gene expression level in the start culture. We observed an induction of ALS3 gene expression in the initial stages of biofilm formation (0.5, 1, and 6 h), whereas at later stages, this gene was also downregulated relative to the gene expression level in the start culture. We also found that biofilms of an als3/als3 deletion mutant contained less filaments at several time points (1, 6, 24, and 48 h), although filamentation as such was not affected in this strain. Together, our data indicate an important role for ALS3 in the early phases of biofilm formation in the CDC reactor, probably related to adhesion of filaments, while the role of ALS1 is less clear.     

Pattern recognition receptors in infectious skin diseases

During the last decade, multiple pattern recognition receptors (PRRs) have been identified. These are involved in the innate immune response against a plethora of pathogens. However, PRR functioning can also be detrimental, even during infections. This review discusses the current knowledge on PRRs that recognize dermatotropic pathogens, and potential therapeutical implications.     

Sialic acid O-acetylation: From biosynthesis to roles in health and disease

Sialic acids are nine-carbon sugars that frequently cap glycans at the cell surface in cells of vertebrates as well as cells of certain types of invertebrates and bacteria. The nine-carbon backbone of sialic acids can undergo extensive enzymatic modification in nature and O-acetylation at the C-4/7/8/9 position in particular is widely observed. In recent years, the detection and analysis of O-acetylated sialic acids have advanced, and sialic acid-specific O-acetyltransferases (SOATs) and O-acetylesterases (SIAEs) that add and remove O-acetyl groups, respectively, have been identified and characterized in mammalian cells, invertebrates, bacteria, and viruses. These advances now allow us to draw a more complete picture of the biosynthetic pathway of the diverse O-acetylated sialic acids to drive the generation of genetically and biochemically engineered model cell lines and organisms with altered expression of O-acetylated sialic acids for dissection of their roles in glycoprotein stability, development, and immune recognition, as well as discovery of novel functions. Furthermore, a growing number of studies associate sialic acid O-acetylation with cancer, autoimmunity, and infection, providing rationale for the development of selective probes and inhibitors of SOATs and SIAEs. Here, we discuss the current insights into the biosynthesis and biological functions of O-acetylated sialic acids and review the evidence linking this modification to disease. Furthermore, we discuss emerging strategies for the design, synthesis, and potential application of unnatural O-acetylated sialic acids and inhibitors of SOATs and SIAEs that may enable therapeutic targeting of this versatile sialic acid modification.     

Challenges in multi-plex and mono-plex platforms for the discovery of inflammatory profiles in neurodegenerative diseases

Pro and anti-inflammatory cytokines are involved in disease onset and pathophysiology of multiple sclerosis, Alzheimer's disease and Parkinson's disease. It is likely that panels of multiple cytokines provide a good reflection of disease status and can be used as biological markers in body fluids. Different multi-plex platforms, Luminex-xMAP and Meso Scale Discovery, are able to detect multiple analytes in the same sample at the same time. In this literature based review, we offer an overview of the multi-plex platforms and compare them with the golden standard ELISA in their ability to accurately and sensitively detect cytokines in cerebrospinal fluid (CSF) and blood (serum/plasma). The detectability and levels of cytokines in multiple sclerosis, Alzheimer's disease and Parkinson's disease are promising but also show discrepancies between studies. The current immuno-assays lack sensitivity for detection of various cytokines that have low concentrations of cytokines in CSF and blood, and therefore technical improvements are needed. With such improvements the use of large panels of cytokines as inflammatory profiles may offer additional value in diagnosis, prognosis and therapeutic response in neurodegenerative diseases.