Search results for "PEPTIDE"
showing 10 items of 4589 documents
Identification of epitopes of Mycobacterium tuberculosis 16-kDa protein recognized by human leukocyte antigen-A*0201 CD8(+) T lymphocytes.
2002
CD8(+) T cells could make an important contribution to protection against tuberculosis (TB), but the antigenic determinants recognized in the context of major histocompatibility complex class I molecules remain ill defined. Our aim was to identify nonamer peptides derived from the acr/16-kDa antigen. Two immunogenic peptides (p21-29 and p120-128) were identified by their ability to elicit cytotoxic CD8(+) T cells from juvenile patients recovering from TB. Epitope-specific recognition was demonstrated by the lysis of both Mycobacterium tuberculosis-infected and peptide-pulsed macrophages, the release of cytotoxic granules, and interferon-gamma and tumor necrosis factor-alpha production. CD8(…
Cloning and characterization of PRA1, a gene encoding a novel pH-regulated antigen of Candida albicans.
1998
ABSTRACT Candida albicans is an opportunistic fungal pathogen of humans. The cell wall of the organism defines the interface between the pathogen and host tissues and is likely to play an essential and pivotal role in the host-pathogen interaction. The components of the cell wall critical to this interaction are undefined. Immunoscreening of a lambda expression library with sera raised against mycelial cell walls of C. albicans was used to identify genes encoding cell surface proteins. One of the positive clones represented a candidal gene that was differentially expressed in response to changes in the pH of the culture medium. Maximal expression occurred at neutral pH, with no expression d…
Polyaspartylhydrazide Copolymer-Based Supramolecular Vesicular Aggregates as Delivery Devices for Anticancer Drugs
2008
In this paper we report on three different hydrophilic copolymers based on alpha,beta-polyaspartylhydrazide (PAHy) bearing butyric groups in the side chain (C 4) (PAHy-C 4) or a combination of butyric groups and positive charged residues ((carboxypropyl)trimethylammonium chloride, CPTACl) (PAHy-C 4-CPTA) that were synthesized and used for the preparation of new supramolecular vesicular aggregates (SVAs) containing gemcitabine as an antitumor drug. Gemcitabine-loaded SVAs containing synthesized PAHy derivatives were characterized from the physicochemical and technological point of view and the in vitro toxicity and anticancer activity on two different human cancer cell lines, i.e., CaCo-2 (h…
Mollusk antimicrobial peptides A review from activity-based evidences to computer-assisted sequences
2011
Antimicrobial peptides (AMPs) represent the most universal immune effectors. Molluscs constitute the second largest animal phylum, after Arthropods, in term of number of species. Only a negligible number has been investigated regarding AMPs. The choice of the species to be studied relied on their economical importance and availability. First studies on molluscan AMPs dated from 1996 and were based on biological activities of biochemical-purified fractions. Such approach released all the original structures we know, with biological activity sometimes different from one isoform to another. Then, molecular biology techniques were applied to molluscan AMPs starting in 1999. Complete screening o…
Identification of antimicrobial peptides in the gonad of European sea bass males and females
2015
In vertebrates, the gonad is considered an immunologically privileged site as it triggers lower immune responses aiming to avoid germ cell damage. In fish,several studies reported that leucocytes show conditioned immune response and modulate some reproductive functions, allowing the pathogen to establish chronic and latent infections into reproductive organs. In mammals, antimicrobial peptides (AMPs) have recently been recognised as important effectors in male reproductive tract immunity. In fish, AMPs are increasingly recognized as a critical first line of defence against many pathogens as bacteria, fungi, virus, protozoa and even tumour cells. We have recently determined that the European…
Role of the virulence plasmid pR99 and the metalloprotease Vvp in resistance of Vibrio vulnificus serovar E to eel innate immunity
2007
Vibrio vulnificus biotype 2 serovar E (VSE) is a bacterial pathogen that produces a haemorrhagic septicaemia called vibriosis in eels. Its ability to grow in blood is conferred by a recently described virulence plasmid [Lee CT, Amaro C, Wu KM, Valiente E, Chang YF, Tsai SF, et al. A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid. Journal of Bacteriology, submitted for publication.]. In this study, we analyzed the role of this plasmid together with the role played by the metalloprotease (Vvp) in the interaction between bacteria and eel innate immunity. To this end, we compared and statistically analyzed the differences in resistance …
Effect of polyphenols on enniatins-induced cytotoxic effects in mammalian cells
2012
Enniatins (ENs) are fungal secondary metabolites produced by genus Fusarium. The ENs exert antimicrobial and insecticidal effect, and has also been demonstrated cytotoxic effects on several mammalian cell lines. On the other hands, it has been proved that natural polyphenols have antioxidant effect. In this study, cell effects at low levels of exposure of four ENs (A, A(1), B and B(1)) and five polyphenols (quercetin, quercetin-3-β-D-glucoside, rutin, myricetin and t-pterostilbene) present in wine; and the cytoprotective effect of these polyphenols exposed simultaneously with ENs in Chinese Hamster Ovary (CHO-K1) cells, were studied. Cell effects were determined by the MTT test after 24 h o…
The symbiosis between Nicotiana tabacum and the endomycorrhizal fungus Funneliformis mosseae increases the plant glutathione level and decreases leaf…
2015
Over time, anthropogenic activities have led to severe cadmium (Cd) and arsenic (As) pollution in several environments. Plants inhabiting metal(loid)-contaminated areas should be able to sequester and detoxify these toxic elements as soon as they enter roots and leaves. We postulated here that an important role in protecting plants from excessive metal(loid) accumulation and toxicity might be played by arbuscular mycorrhizal (AM) fungi. In fact, human exploitation of plant material derived from Cd- and As-polluted environments may lead to a noxious intake of these toxic elements; in particular, a possible source of Cd and As for humans is given by cigarette and cigar smoke. We investigated …
Salmon (Salmo salar) side streams as a bioresource to obtain potential antioxidant peptides after applying pressurized liquid extraction (PLE)
2021
The pressurized liquid extraction (PLE) technique was used to obtain protein extracts with antioxidant capacity from salmon muscle remains, heads, viscera, skin, and tailfins. A protein recovery percentage ≈28% was obtained for all samples except for viscera, which was ≈92%. These values represented an increase of 1.5–4.8-fold compared to stirring extraction (control). Different SDS-PAGE profiles in control and PLE extracts revealed that extraction conditions affected the protein molecular weight distribution of the obtained extracts. Both TEAC (Trolox equivalent antioxidant capacity) and ORAC (oxygen radical antioxidant capacity) assays showed an outstanding antioxidant activity for viscer…
Molecular Characterization of White Wines Antioxidant Metabolome by Ultra High Performance Liquid Chromatography High-Resolution Mass Spectrometry
2020
International audience; The knowledge about the molecular fraction contributing to white wines oxidative stability is still poorly understood. However, the role of S- and N-containing compounds, like glutathione and other peptides, as a source of reductant in many oxidation reactions, and acting against heavy metals toxicity, or lipid and polyphenol oxidation as ROS-scavenger is today very well established. In that respect, the aim of the present study is to introduce an original analytical tool for the direct determination of the available nucleophilic compounds in white wine under acidic pH conditions. One step derivatization of nucleophiles has been realized directly in wines using 4-met…