Background Middle East respiratory syndrome (MERS) coronavirus causes a highly fatal lower-respiratory tract infection. There are as yet no licensed MERS vaccines or therapeutics. This study (WRAIR-2274) assessed the safety, tolerability, and immunogenicity of the GLS-5300 MERS coronavirus DNA vaccine in healthy adults. Methods This study was a phase 1, open-label, single-arm, dose-escalation study of GLS-5300 done at the Walter ReedArmy Institute for Research Clinical Trials Center (Silver Spring, MD, USA). We enrolled healthy adults aged 18-50 years; exclusion criteria included previous infection or treatment of MERS. Eligible participants were enrolled sequentially using a dose-escalation protocol to receive 0·67 mg, 2 mg, or 6 mg GLS-5300 administered by trained clinical site staff via a single intramuscular 1 mL injection at each vaccination at baseline, week 4, and week 12 followed immediately by co-localised intramuscular electroporation. Enrolment into the higher dose groups occurred after a safety monitoring committee reviewed the data following vaccination of the first five participants at the previous lower dose in each group. The primary outcome of the study was safety, assessed in all participants who received at least one study treatment and for whom post-dose study data were available, during the vaccination period with follow-up through to 48 weeks after dose 3. Safety was measured by the incidence of adverse events; administration site reactions and pain; and changes in safety laboratory parameters. The secondary outcome was immunogenicity. This trial is registered at ClinicalTrials.gov (number NCT 02670187) and is completed.Findings Between Feb 17 and July 22, 2016, we enrolled 75 individuals and allocated 25 each to 0·67 mg, 2 mg, or 6 mg GLS-5300. No vaccine-associated serious adverse events were reported. The most common adverse events were injection-site reactions, reported in 70 participants (93%) of 75. Overall, 73 participants (97%) of 75 reported at least one solicited adverse event; the most common systemic symptoms were headache (five [20%] with 0·67 mg, 11 [44%] with 2 mg, and seven [28%] with 6 mg), and malaise or fatigue (five [20%] with 0·67 mg, seven [28%] with 2 mg, and two [8%] with 6 mg). The most common local solicited symptoms were administration site pain (23 [92%] with all three doses) and tenderness (21 [84%] with all three doses). Most solicited symptoms were reported as mild (19 [76%] with 0·67 mg, 20 [80%] with 2 mg, and 17 [68%] with 6 mg) and were self-limiting. Unsolicited symptoms were reported for 56 participants (75%) of 75 and were deemed treatment-related for 26 (35%). The most common unsolicited adverse events were infections, occurring in 27 participants (36%); six (8%) were deemed possibly related to study treatment. There were no laboratory abnormalities of grade 3 or higher that were related to study treatment; laboratory abnormalities were uncommon, except for 15 increases in creatine phosphokinase in 14 participants (three participants in the 0·67 mg grou...
SummaryReactive oxidant species produced by phagocytes have been reported as being involved in the killing of Aspergillus fumigatus. Fungal superoxide dismutases (SODs) that detoxify superoxide anions could be putative virulence factors for this opportunistic pathogen. Four genes encoding putative Sods have been identified in the A. fumigatus genome: a cytoplasmic Cu/ZnSOD (AfSod1p), a mitochondrial MnSOD (AfSod2p), a cytoplasmic MnSOD (AfSod3p) and AfSod4 displaying a MnSOD C-terminal domain. During growth, AfSOD1 and AfSOD2 were highly expressed in conidia whereas AfSOD3 was only strongly expressed in mycelium. AfSOD4 was weakly expressed compared with other SODs. The deletion of AfSOD4 was lethal. Dsod1 and Dsod2 mutants showed a growth inhibition at high temperature and a hypersensitivity to menadione whereas the sod3 mutant had only a slight growth delay at high temperature. Multiple mutations had only an additive effect on the phenotype. The triple sod1/sod2/sod3 mutant was characterized by a delay in conidial germination, a reduced conidial survival during storage overtime, the highest sensitivity to menadione and an increased sensitivity to killing by alveolar macrophage of immunocompetent mice. In spite of these phenotypes, no significant virulence difference was observed between the triple mutant and parental strain in experimental murine aspergillosis models in immunocompromised animals.
We report here that in addition to a cytoplasmic copper-zinc-containing superoxide dismutase (SOD) and a mitochondrial manganese-containing SOD, Candida albicans expresses a third SOD gene (SOD3). The deduced amino acid sequence contains all of the motifs found in previously characterized manganese-containing SODs, except the presence of a mitochondrial transit peptide. Recombinant Sod3p expressed and purified from Escherichia coli is a homotetramer with a subunit mass of 25.4 kDa. Mass absorption spectrometry detected the presence of both iron and manganese in purified Sod3p but, as determined by metal replacement experiments, the enzyme displays activity only when bound to manganese. Overexpression of SOD3 was shown to rescue the hypersensitivity to redox cycling agents of a Saccharomyces cerevisiae mutant lacking the cytoplasmic copper-zinc-containing SOD. Northern blot analyses showed that the transcription of SOD3 is induced neither by the transition from the yeast to the mycelial form of C. albicans nor by drug-induced oxidative stress. In continuous cultures, the expression of SOD3 was strongly stimulated upon the entry and during the stationary phase, concomitantly with the repression of SOD1. We conclude that Sod3p is an atypical cytosolic manganese-containing superoxide dismutase that is involved in the protection of C. albicans against reactive oxygen species during the stationary phase.
Background: Establishment of aspergillosis is depending upon the exit from dormancy and germination of the conidia of Aspergillus fumigatus in the lung. To gain an understanding of the molecular mechanisms underlying the early steps of conidial germination, we undertook a transcriptomic analysis using macroarrays constructed with PCR fragments from > 3,000 genes (around one third of the annotated A. fumigatus genome).
SummaryGalactofuranose (Galf) is a major molecule found in cell wall polysaccharides, secreted glycoproteins, membrane lipophosphoglycans and sphingolipids of Aspergillus fumigatus. The initial step in the Galf synthetic pathway is the re-arrangement of UDP-galactopyranose to UDP-Galf through the action of UDP-galactopyranose mutase. A mutant lacking the AfUGM1 gene encoding the UDPgalactopyranose mutase has been constructed. In the mutant, though there is a moderate reduction in the mycelial growth associated with an increased branching, it remains as pathogenic and as resistant to cell wall inhibitors and phagocytes as the wild-type parental strain. The major phenotype seen is a modification of the cell wall surface that results in an increase in adhesion of the mutants to different inert surfaces (glass and plastic) and epithelial respiratory cells. The adhesive phenotype is due to the unmasking of the mannan consecutive to the removal of galactofuran by the ugm1 mutation. Removal of the mannan layer from the mutant surface by a mannosidase treatment abolishes mycelial adhesion to surfaces.
Inhibition of glycogen synthase kinase 3β (GSK3β) is a shared action believed to be involved in the regulation of behavior by psychoactive drugs such as antipsychotics and mood stabilizers. However, little is known about the identity of the substrates through which GSK3β affects behavior. We identified fragile X mental retardation-related protein 1 (FXR1P), a RNA binding protein associated to genetic risk for schizophrenia, as a substrate for GSK3β. Phosphorylation of FXR1P by GSK3β is facilitated by prior phosphorylation by ERK2 and leads to its down-regulation. In contrast, behaviorally effective chronic mood stabilizer treatments in mice inhibit GSK3β and increase FXR1P levels. In line with this, overexpression of FXR1P in the mouse prefrontal cortex also leads to comparable mood-related responses. Furthermore, functional genetic polymorphisms affecting either FXR1P or GSK3β gene expression interact to regulate emotional brain responsiveness and stability in humans. These observations uncovered a GSK3β/FXR1P signaling pathway that contributes to regulating mood and emotion processing. Regulation of FXR1P by GSK3β also provides a mechanistic framework that may explain how inhibition of GSK3β can contribute to the regulation of mood by psychoactive drugs in mental illnesses such as bipolar disorder. Moreover, this pathway could potentially be implicated in other biological functions, such as inflammation and cell proliferation, in which FXR1P and GSK3 are known to play a role.
The mycelial surface antigen recognized by monoclonal antibody (mAb) 4E1 has previously been shown to be present predominantly in the terminal third of the hyphal structures in Candida albicans. We report here the expression cloning of the corresponding gene (CSA1 ) by mAb 4E1‐coated magnetic beads sorting of Saccharomyces cerevisiae transformants expressing a C. albicans genomic library. The strategy is both highly selective and highly sensitive and provides an additional genetic tool for the cloning and characterization of C. albicans genes encoding surface proteins. CSA1 is an intronless gene encoding a 1203‐residue protein composed of repetitive motifs and domains. Northern analysis indicates that CSA1 is preferentially expressed during the mycelial growth phase, although a low level of CSA1 mRNA can be detected in the yeast form. As evidenced by indirect immunofluorescence microscopy with mAb 4E1, Csa1p is not randomly distributed over the surface of yeast cells, but localizes predominantly in the growing buds. This suggests that the distribution of Csa1p may be restricted to sites of cell surface elongation. Both heterozygous and homozygous C. albicans csa1Δ mutants are viable. Upon induction of mycelial growth, the number and size of hyphal structures derived from the mutants are similar to those observed in the parental wild‐type strain. The physiological role of Csa1p has yet to be determined. However, the presence in Csa1p of repeated cysteine‐rich hydrophobic domains with significant sequence similarity to motifs found in surface proteins (Ag2 and Pth11) from two distantly related fungal pathogens (Coccidioides immitis and Magnaporthe grisea respectively) suggests a common function in host interaction.
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