Search results for "Peptide"
showing 10 items of 4589 documents
A Naturally Occurring Antibody Fragment Neutralizes Infectivity of Diverse Infectious Agents
2016
AbstractA phosphorylated peptide, named K40H, derived from the constant region of IgMs was detected in human serum by liquid chromatography coupled to high-resolution mass spectrometry. Synthetic K40H proved to exert a potent in vitro activity against fungal pathogens, and to inhibit HIV-1 replication in vitro and ex vivo. It also showed a therapeutic effect against an experimental infection by Candida albicans in the invertebrate model Galleria mellonella. K40H represents the proof of concept of the innate role that naturally occurring antibody fragments may exert against infectious agents, shedding a new light upon the posthumous role of antibodies and opening a new scenario on the multif…
Positive Role of the MHC Class-I Antigen Presentation Regulator m04/gp34 of Murine Cytomegalovirus in Antiviral Protection by CD8 T Cells
2020
Murine cytomegalovirus (mCMV) codes for MHC class-I trafficking modulators m04/gp34, m06/gp48, and m152/gp40. By interacting with the MHC class-Iα chain, these proteins disconnect peptide-loaded MHC class-I (pMHC-I) complexes from the constitutive vesicular flow to the cell surface. Based on the assumption that all three inhibit antigen presentation, and thus the recognition of infected cells by CD8 T cells, they were referred to as “immunoevasins.” Improved antigen presentation mediated by m04 in the presence of m152 after infection with deletion mutant mCMV-Δm06W, compared to mCMV-Δm04m06 expressing only m152, led us to propose renaming these molecules “viral regulators of antigen present…
Identification of New Antimicrobial Peptides from Mediterranean Medical Plant Charybdis pancration (Steinh.) Speta
2020
The present work was designed to identify and characterize novel antimicrobial peptides (AMPs) from Charybdis pancration (Steinh.) Speta, previously named Urginea maritima, is a Mediterranean plant, well-known for its biological properties in traditional medicine. Polypeptide-enriched extracts from different parts of the plant (roots, leaves and bulb), never studied before, were tested against two relevant pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. With the aim of identifying novel natural AMPs, peptide fraction displaying antimicrobial activity (the bulb) that showed minimum inhibitory concentration (MICs) equal to 30 µ
Dosing of caspofungin based on a pharmacokinetic/pharmacodynamic index for the treatment of invasive fungal infections in critically ill patients on …
2017
Abstract Introduction The study objective was to evaluate the efficacy of different dosages of caspofungin in the treatment of invasive candidiasis and aspergillosis, in relation to the probability of pharmacokinetic/pharmacodynamic (PK/PD) target attainment, using modelling and Monte Carlo simulations in critically ill adult patients on continuous haemodiafiltration. Methods Critically ill adult patients on continuous venovenous haemodiafiltration treated with caspofungin were analysed. A population PK model was developed. Four caspofungin dosing regimens were simulated: the licensed regimen, 70 mg/day, 100 mg/day or 200 mg/day. A PK/PD target was defined as the ratio between the area unde…
Efficacy and safety of dalbavancin in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and other infections in a real-li…
2020
Objectives: We evaluated the efficacy and safety of dalbavancin in ABSSSI and ‘other sites’ infections’ (OTA). Methods: Observational study involving 11 Italian hospitals including patients that received ≥1 dose of dalbavancin in 2016–2019. The outcome was end-of-treatment efficacy and safety in ABSSSI and OTA in a real-life setting. Results: 206 patients enrolled (males 50%, median age 62 [IQR 50–76] years), 60.2% ABSSSI, 39.8% OTA. 69.7% ABSSSI vs 90.7% OTA (p = 0.003) and 46.3% ABSSSI vs 37.2% OTA (p = 0.786) received previous and concomitant antibiotics, respectively. 82.5% reached clinical cure. Eleven (5.4%) patients had non-serious adverse events (AE). OTA patients showed longer hosp…
Identification of a Peptide Produced by Bifidobacterium longum CECT 7210 with Antirotaviral Activity
2016
Rotavirus is one of the main causes of acute diarrhea and enteritis in infants. Currently, studies are underway to assess the use of probiotics to improve rotavirus vaccine protection. A previous work demonstrated that the probiotic strain Bifidobacterium longum subsp. infantis CECT 7210 is able to hinder rotavirus replication both in vitro and in vivo. The present study takes a systematic approach in order to identify the molecule directly involved in rotavirus inhibition. Supernatant protease digestions revealed both the proteinaceous nature of the active substance and the fact that the molecule responsible for inhibiting rotavirus replication is released to the supernatant. Following pur…
Klebsiella pneumoniae Lipopolysaccharides Serotype O2afg Induce Poor Inflammatory Immune Responses Ex Vivo
2021
Currently, Klebsiella pneumoniae is a pathogen of clinical relevance due to its plastic ability of acquiring resistance genes to multiple antibiotics. During K. pneumoniae infections, lipopolysaccharides (LPS) play an ambiguous role as they both activate immune responses but can also play a role in immune evasion. The LPS O2a and LPS O2afg serotypes are prevalent in most multidrug resistant K. pneumoniae strains. Thus, we sought to understand if those two particular LPS serotypes were involved in a mechanism of immune evasion. We have extracted LPS (serotypes O1, O2a and O2afg) from K. pneumoniae strains and, using human monocytes ex vivo, we assessed the ability of those LPS antigens to in…
Gut Microbiome Associates With Lipid-Lowering Effect of Rosuvastatin in Vivo
2018
Source at https://doi.org/10.3389/fmicb.2018.00530 . Background: Statin has been widely used to treat hyperlipidemia because of its high potency in decreasing cholesterol levels. The present study aimed to examine the lipid-lowering effect of rosuvastatin and the composition, diversity and species abundance of gut microbiome in association with rosuvastatin efficacy. TRIAL REGISTRATION: ChiCTR-ORC-17013212 at the First Affiliated Hospital of Dalian Medical University, November 2, 2017. Results:Totally 64 patients with hyperlipidemia were treated with 10 mg/day of rosuvastatin for 4-8 weeks. Blood lipid indicators triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL), lo…
Immunodominant Cytomegalovirus Epitopes Suppress Subdominant Epitopes in the Generation of High-Avidity CD8 T Cells
2021
CD8+ T-cell responses to pathogens are directed against infected cells that present pathogen-encoded peptides on MHC class-I molecules. Although natural responses are polyclonal, the spectrum of peptides that qualify for epitopes is remarkably small even for pathogens with high coding capacity. Among those few that are successful at all, a hierarchy exists in the magnitude of the response that they elicit in terms of numbers of CD8+ T cells generated. This led to a classification into immunodominant and non-immunodominant or subordinate epitopes, IDEs and non-IDEs, respectively. IDEs are favored in the design of vaccines and are chosen for CD8+ T-cell immunotherapy. Using murine cytomegalov…
Complex Regulatory Networks Governing Production of the Glycopeptide A40926
2018
Glycopeptides (GPAs) are an important class of antibiotics, with vancomycin and teicoplanin being used in the last 40 years as drugs of last resort to treat infections caused by Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus. A few new GPAs have since reached the market. One of them is dalbavancin, a derivative of A40926 produced by the actinomycete Nonomuraea sp. ATCC 39727, recently classified as N. gerenzanensis. This review summarizes what we currently know on the multilevel regulatory processes governing production of the glycopeptide A40926 and the different approaches used to increase antibiotic yields. Some nutrients, e.g., valine, l-glutamine and mal…