The outbreak of the SARS-CoV-2 global pandemic heightened the pace of vaccine development with various vaccines being approved for human use in a span of 24 months. The SARS-CoV-2 trimeric spike (S) surface glycoprotein, which mediates viral entry by binding to ACE2, is a key target for vaccines and therapeutic antibodies. Plant biopharming is recognized for its scalability, speed, versatility, and low production costs and is an increasingly promising molecular pharming vaccine platform for human health.
View Article and Find Full Text PDFNext generation vaccines have the capability to contribute to and revolutionise the veterinary vaccine industry. African horse sickness (AHS) is caused by an arbovirus infection and is characterised by respiratory distress and/or cardiovascular failure and is lethal to horses. Mandatory annual vaccination in endemic areas curtails disease occurrence and severity.
View Article and Find Full Text PDFWe investigated the effects of low oxygen storage on chilling injury development, colour development, respiration and HO levels of 'Merlice' tomatoes cultivated with and without far red (FR) LED lighting during 20 days of shelf-life. Mature green (MG) and red (R) tomatoes were stored at 2 °C in combination with 0.5, 2.
View Article and Find Full Text PDFAiming to improve the treatment outcomes of current daily tuberculosis (TB) chemotherapy over several months, we investigated whether nanoencapsulation of existing drugs would allow decreasing the treatment frequency to weekly, thereby ultimately improving patient compliance. Nanoencapsulation of three first-line anti-TB drugs was achieved by a unique, scalable spray-drying technology forming free-flowing powders in the nanometer range with encapsulation efficiencies of 82, 75, and 62% respectively for rifampicin, pyrazinamide, and isoniazid. In a pre-clinical study on TB infected mice, we demonstrate that the encapsulated drugs, administered once weekly for nine weeks, showed comparable efficacy to daily treatment with free drugs over the same experimental period.
View Article and Find Full Text PDFThe differentiation of macrophages into lipid-filled foam cells is a hallmark of the lung granuloma that forms in patients with active tuberculosis (TB). Mycolic acids (MAs), the abundant lipid virulence factors in the cell wall of (Mtb), can induce this foam phenotype possibly as a way to perturb host cell lipid homeostasis to support the infection. It is not exactly clear how MAs allow differentiation of foam cells during Mtb infection.
View Article and Find Full Text PDFMycolic acids (MAs) are highly hydrophobic long-chain α-alkyl β-hydroxy fatty acids present in the cell wall of Mycobacterium tuberculosis (Mtb) as a complex mixture of molecules with a common general structure but with variable functional groups in the meromycolate chain. In this study, we addressed the relationship between the MA molecular structure and their contribution to the development of T-cell immune responses. Hereto, we used the model antigen ovalbumin and single synthetic MAs, differing in oxygenation class and cis versus trans proximal cyclopropane configuration, as immune stimulatory agents.
View Article and Find Full Text PDFThe co-immobilization of enzymes on target surfaces facilitates the development of self-contained, multi-enzyme biocatalytic platforms. This generally entails the co-immobilization of an enzyme with catalytic value in combination with another enzyme that performs a complementary function, such as the recycling of a critical cofactor. In this study, we co-immobilized two enzymes from different biological sources for the continuous reduction of nitric oxide, using epoxide- and carboxyl-functionalized hyper-porous microspheres.
View Article and Find Full Text PDFThe appearance of drug-resistant strains of Mycobacterium tuberculosis (Mtb) poses a great challenge to the development of novel treatment programmes to combat tuberculosis. Since innovative nanotechnologies might alleviate the limitations of current therapies, we have designed a new nanoformulation for use as an anti-TB drug delivery system. It consists of incorporating mycobacterial cell wall mycolic acids (MA) as targeting ligands into a drug-encapsulating Poly dl-lactic-co-glycolic acid polymer (PLGA), via a double emulsion solvent evaporation technique.
View Article and Find Full Text PDFMycolic acids are structural components of the mycobacterial cell wall that have been implicated in the pathogenicity and drug resistance of certain mycobacterial species. They also offer potential in areas such as rapid serodiagnosis of human and animal tuberculosis. It is increasingly recognized that conformational behavior of mycolic acids is very important in understanding all aspects of their function.
View Article and Find Full Text PDFNitric oxide reductase (NOR) of the P450 oxidoreductase family accepts electrons directly from its cofactor, NADH, to reduce two nitric oxide (NO) molecules to one nitrous oxide molecule and water. The enzyme plays a key role in the removal of radical NO produced during respiratory metabolism, and applications in bioremediation and biocatalysis have been identified. However, a rapid, accurate, and sensitive enzyme assay has not yet been developed for this enzyme family.
View Article and Find Full Text PDFPatient serum antibodies to mycolic acids have the potential to be surrogate markers of active tuberculosis (TB) when they can be distinguished from the ubiquitously present cross-reactive antibodies to cholesterol. Mycolic acids are known to interact more strongly with antibodies present in the serum of patients with active TB than in patients with latent TB or no TB. Examples of single stereoisomers of mycolic acids with chain lengths corresponding to major homologues of those present in Mycobacterium tuberculosis have now been synthesised with a sulfur substituent on the terminal position of the α-chain; initial studies have established that one of these binds to a gold electrode surface, offering the potential to develop second generation sensors for diagnostic patient antibody detection.
View Article and Find Full Text PDFMycolic acids constitute the waxy layer of the outer cell wall of Mycobacterium spp. and a few other genera. They are diverse in structure, providing a unique chromatographic foot-print for almost each of the more than 70 Mycobacterium species.
View Article and Find Full Text PDFCell wall mycolic acids (MA) from Mycobacterium tuberculosis (M.tb) are CD1b presented antigens that can be used to detect antibodies as surrogate markers of active TB, even in HIV coinfected patients. The use of the complex mixtures of natural MA is complicated by an apparent antibody cross-reactivity with cholesterol.
View Article and Find Full Text PDFUnlabelled: The remarkable physicochemical properties of particles in the nanometer range have been proven to address many challenges in the field of science. However, the possible toxic effects of these particles have raised some concerns. The aim of this article is to evaluate the effects of poly(lactide-co-glycolide) (PLGA) nanoparticles in vitro and in vivo compared to industrial nanoparticles of a similar size range such as zinc oxide, ferrous oxide, and fumed silica.
View Article and Find Full Text PDFThe integrity and properties of mycolic acid (MA) antigens integrated into a self-assembled monolayer (SAM) of N-(2-mercaptoethyl)octadecanamide, (MEODA), on a gold electrode have been interrogated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). EIS data showed that Au-MEODA and Au-MEODA-MA behave as microelectrode arrays, with pinholes acting as the microelectrodes that permit electron transport between a redox-active probe in solution and the underlying gold surface. The average radii of the pinholes (r(a)) and half the distance between the centers of the neighbouring pinholes (r(b)), were estimated from EIS using the pore size model, and discussed.
View Article and Find Full Text PDFElectrochemical impedimetric recognition by anti-mycolic acid antibodies, present in tuberculosis (TB)-positive human serum co-infected with human immunodeficiency virus (HIV), of mycolic acids (MA) integrated into a self-assembled monolayer of N-(2-mercaptoethyl)octadecanamide on a gold electrode is described, proving that the MA-based electrode can satisfactorily discriminate between a TB-positive and a TB-negative serum, thus offering promise as a potential impedimetric immunosensing platform for active tuberculosis.
View Article and Find Full Text PDFMycolic acids (MAs) are a major component of the cell walls of Mycobacterium tuberculosis and related organisms. These alpha-alkyl beta-hydroxy long fatty acids have been the subject of numerous studies for their immunological properties. We previously reported that an interaction between cholesterol and mycolic acids could be responsible for the low accuracy in the serodiagnosis of TB when using free mycolic acid in an ELISA assay.
View Article and Find Full Text PDFTuberculosis has re-emerged as a global health problem due to co-infection with HIV and the emergence of drug-resistant strains of Mycobacterium tuberculosis. HIV co-infection introduced a 30% underestimation in TB diagnosis based on sputum analysis, calling for a reliable and fast serodiagnostic assay to assist in the management of TB in HIV-burdened populations. Serodiagnosis with mycobacterial lipid cell wall antigens gave promising results, in particular with LAM and cord factor.
View Article and Find Full Text PDFRationale: Mycolic acid (MA) constitutes a major and distinguishing cell wall biolipid from Mycobacterium tuberculosis. MA interferes with the lipid homeostasis of alveolar macrophages, inducing differentiation into foamy macrophages exhibiting increased proinflammatory function.
Objectives: We verified the interference of this altered macrophage function with inhaled antigen-triggered allergic airway inflammation and underlying Th2 lymphocyte reactivity.
Recognition of conserved pathogen-associated molecular patterns constitutes a crucial step in the initiation of innate immune responses. We studied the contribution to the host-pathogen interaction of mycolic acid (MA), a major lipid component of the cell envelope of the macrophage intracellular pathogen Mycobacterium tuberculosis and other mycobacteria. MA administered to the peritoneal cavity or to the airways induced a unique macrophage morphotype, similar to the foamy macrophage derivatives observed in tuberculous granulomas and characterized by intracellular accumulation of neutral lipids and entry into mitosis.
View Article and Find Full Text PDFIsolation and purification of mycolic acids from Mycobacterium tuberculosis have allowed them to be applied as antigen in an ELISA-based assay to detect specific antibodies in human sera. Tuberculosis patients have previously been shown to contain antimycolic acids antibodies. The aim of this study was to determine whether human immunodeficiency virus (HIV) co-infection increases false-negative testing rate and whether other random diseases for which hospitalisation is normally required will contribute to false-positive results.
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