EClinicalMedicine
June 2022
Background: Advances in therapeutic drugs have increased life-expectancies for HIV-infected individuals, but the need for an effective vaccine remains. We assessed safety and immunogenicity of HIV-1 vaccine, Trimer 4571 (BG505 DS-SOSIP.664) adjuvanted with aluminum hydroxide (alum), in HIV-negative adults.
View Article and Find Full Text PDFBackground: Western (WEEV), eastern (EEEV), and Venezuelan (VEEV) equine encephalitis viruses are mosquito-borne pathogens classified as potential biological warfare agents for which there are currently no approved human vaccines or therapies. We aimed to evaluate the safety, tolerability, and immunogenicity of an investigational trivalent virus-like particle (VLP) vaccine, western, eastern, and Venezuelan equine encephalitis (WEVEE) VLP, composed of WEEV, EEEV, and VEEV VLPs.
Methods: The WEVEE VLP vaccine was evaluated in a phase 1, randomised, open-label, dose-escalation trial at the Hope Clinic of the Emory Vaccine Center at Emory University, Atlanta, GA, USA.
Currently, licensed seasonal influenza vaccines display variable vaccine effectiveness, and there remains a need for novel vaccine platforms capable of inducing broader responses against viral protein domains conserved among influenza subtypes. We conducted a first-in-human, randomized, open-label, phase 1 clinical trial ( NCT03186781 ) to evaluate a novel ferritin (H2HA-Ferritin) nanoparticle influenza vaccine platform. The H2 subtype has not circulated in humans since 1968.
View Article and Find Full Text PDFControl over cellular delivery of different functionalities and their synchronized activation is a challenging task. We report several RNA and RNA/DNA-based nanoparticles designed to conditionally activate the RNA interference in various human cells. These nanoparticles allow precise control over their formulation, stability in blood serum, and activation of multiple functionalities.
View Article and Find Full Text PDFControl over the simultaneous delivery of different functionalities and their synchronized intracellular activation can greatly benefit the fields of RNA and DNA biomedical nanotechnologies and allow for the production of nanoparticles and various switching devices with controllable functions. We present a system of multiple split functionalities embedded in the cognate pairs of RNA-DNA hybrids which are programmed to recognize each other, re-associate and form a DNA duplex while also releasing the split RNA fragments which upon association regain their original functions. Simultaneous activation of three different functionalities (RNAi, Förster resonance energy transfer and RNA aptamer) confirmed by multiple in vitro and cell culture experiments prove the concept.
View Article and Find Full Text PDFA flagellin-independent caspase-1 activation pathway that does not require NAIP5 or NRLC4 is induced by the intracellular pathogen Legionella pneumophila. Here we demonstrate that this pathway requires caspase-11. Treatment of macrophages with LPS up-regulated the host components required for this caspase-11 activation pathway.
View Article and Find Full Text PDFMethods Mol Biol
April 2013
Caspase-1 is a critical factor in the innate immune response to Legionella pneumophila. The development of methods for analyzing caspase-1 activation pathways and downstream caspase-1-associated activities has helped in understanding the regulation of this protease and the signaling components involved. Here we outline methods for directly detecting active caspase-1, measuring caspase-1 activities and analyzing components involved in the regulation of caspase-1 during L.
View Article and Find Full Text PDFPathogens are detected by a variety of innate immune sensors in host cells leading to rapid induction of cell autonomous responses. Proinflammatory cytokine secretion and a specialized form of inflammatory cell death called pyroptosis are induced during infection through activation of caspase-1. Pathogen-induced caspase-1 activation is regulated in large part by a vast array of cystosolic sensor proteins, including NLRs and AIM2, and an adaptor protein called ASC.
View Article and Find Full Text PDFUnlabelled: Nucleotide-binding domain, leucine-rich repeat containing proteins (NLRs) activate caspase-1 in response to a variety of bacterium-derived signals in macrophages. NLR-mediated activation of caspase-1 by Legionella pneumophila occurs through both an NLRC4/NAIP5-dependent pathway and a pathway requiring the adapter protein Asc. Both pathways are needed for maximal activation of caspase-1 and for the release of the cytokines interleukin-1β (IL-1β) and IL-18.
View Article and Find Full Text PDFDendritic cells (DCs) are specialized phagocytes that internalize exogenous antigens and microbes at peripheral sites, and then migrate to lymphatic organs to display foreign peptides to naïve T cells. There are several examples where DCs have been shown to be more efficient at restricting the intracellular replication of pathogens compared to macrophages, a property that could prevent DCs from enhancing pathogen dissemination. To understand DC responses to pathogens, we investigated the mechanisms by which mouse DCs are able to restrict replication of the intracellular pathogen Legionella pneumophila.
View Article and Find Full Text PDFCaspase-1 activation is a key feature of the innate immune response of macrophages elicited by pathogens and a variety of toxins. Here, we determined the requirement for different adapter proteins involved in regulating host processes mediated by caspase-1 after macrophage infection by Legionella pneumophila. The adapter protein Asc was found to be important for caspase-1 activation during L.
View Article and Find Full Text PDFMethanocaldococcus jannaschii, a deeply rooted hyperthermophilic anaerobic methanarchaeon from a deep-sea hydrothermal vent, carries an NADH oxidase (Nox) homologue (MJ0649). According to the characteristics described here, MJ0649 represents an unusual member within group 3 of the flavin-dependent disulfide reductase (FDR) family. This FDR group comprises Nox, NADH peroxidases (Npx) and coenzyme A disulfide reductases (CoADRs); each carries a Cys residue that forms Cys-sulfenic acid during catalysis.
View Article and Find Full Text PDFThe immune system must discriminate between pathogenic and nonpathogenic microbes in order to initiate an appropriate response. Toll-like receptors (TLRs) detect microbial components common to both pathogenic and nonpathogenic bacteria, whereas Nod-like receptors (NLRs) sense microbial components introduced into the host cytosol by the specialized secretion systems or pore-forming toxins of bacterial pathogens. The host signaling pathways that respond to bacterial secretion systems remain poorly understood.
View Article and Find Full Text PDFTyr235 of GTP-dependent phosphoenolpyruvate (PEP) carboxykinase is a fully invariant residue. The aromatic ring of this residue establishes an energetically favorable weak anion-quadrupole interaction with PEP carboxylate. The role of Tyr235 in catalysis was investigated via kinetic analysis of site-directed mutagenesis-derived variants.
View Article and Find Full Text PDFWe report the first kinetic characterization of human liver cytosolic GTP-dependent phosphoenolpyruvate carboxykinase (GTP-PEPCK), which plays a major role in the development of type 2 diabetes in human. In this work two recombinant forms of the enzyme were studied. One form had a His10-tag and the other was His-tag-free, and with one exception, both exhibited similar kinetic properties.
View Article and Find Full Text PDFThe roles of Asp(75), Asp(78), and Glu(83) of the (75)DPSDVARVE(83) element of Mycobacterium smegmatis GTP-dependent phosphoenolpyruvate (PEP) carboxykinase (GTP-PEPCK) were investigated. Asp(78) and Glu(83) are fully conserved in GTP-PEP-CKs. The human PEPCK crystal structure suggests that Asp(78) influences Tyr(220); Tyr(220) helps to position bound PEP, and Glu(83) interacts with Arg(81).
View Article and Find Full Text PDFPre-event identification of a specific cardiac substrate abnormality in a patient is an important step in preventing sudden cardiac death (SCD) in the pediatric and adult population. Certain cardiac substrate abnormalities can render the patient "at risk" for SCD and strategies for prevention of SCD in children must involve the identification and subsequent modification of these cardiac substrates.
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