Cationic antimicrobial peptides (CAMP) represent a conserved and highly effective component of innate immunity. During infection, the Gram-negative pathogen Salmonella typhimurium induces different mechanisms of CAMP resistance that promote pathogenesis in animals. This study shows that exposure of S. typhimurium to sublethal concentrations of CAMP activates the PhoP/PhoQ and RpoS virulence regulons, while repressing the transcription of genes required for flagella synthesis and the invasion-associated type III secretion system. We further demonstrate that growth of S. typhimurium in low doses of the alpha-helical peptide C18G induces resistance to CAMP of different structural classes. Inducible resistance depends on the presence of PhoP, indicating that the PhoP/PhoQ system can sense sublethal concentrations of cationic antimicrobial peptides. Growth of S. typhimurium in the presence of CAMP also leads to RpoS-dependent protection against hydrogen peroxide. Because bacterial resistance to oxidative stress and CAMP are induced during infection of animals, CAMP may be an important signal recognized by bacteria on colonization of animal tissues.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1046/j.1365-2958.2003.03675.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cholesterol-terminated cationic lipidated oligomers (CLOs) as a new class of antifungals.
J Mater Chem B
January 2025
Drug Delivery, Disposition, and Dynamics Theme, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Pde, Parkville, VIC, 3052, Australia.
Infections caused by fungal pathogens are a global health problem, and have created an urgent need for new antimicrobial strategies. This report details the synthesis of lipidated 2-vinyl-4,4-dimethyl-5-oxazolone (VDM) oligomers an optimized Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) approach. Cholesterol-Br was used as an initiator to synthesize a library of oligo-VDM (degree of polymerisation = 5, 10, 15, 20, and 25), with an α-terminal cholesterol group.
View Article and Find Full Text PDFFullerene (C & C)-Meso-Tris-4-Carboxyphenyl Porphyrin Dyads Inhibit Entry of Wild-Type and Drug-Resistant HIV-1 Clades B and C.
J Med Virol
February 2025
Department of Chemistry, Assam University, Silchar, India.
The biological applications of noncationic porphyrin-fullerene (P-F) dyads as anti-HIV agents have been limited despite the established use of several cationic P-F dyads as anti-cancer photodynamic therapy (PDT) agents. This article explores the potential of amphiphilic non-cationic porphyrin-fullerene dyads as HIV-1 inhibitors under both PDT (light-treated) and non-PDT (dark) conditions. The amphiphilic P-F dyads, PBC and PBC, demonstrated enhanced efficacy in inhibiting the entry and production of HIV-1 (subtypes B and C).
View Article and Find Full Text PDFSynthesis, Characterization, and Antimicrobial Activity of Urea-Containing α/β Hybrid Peptides against and Methicillin-Resistant .
ACS Omega
January 2025
Infectious Diseases Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, Jammu and Kashmir 180001, India.
The insertion of β-amino acids and replacement of the amide bond with a urea bond in antimicrobial peptide sequences are promising approaches to enhance the antibacterial activity and improve proteolytic stability. Herein, we describe the synthesis, characterization, and antibacterial activity of short αβ cationic hybrid peptides LA-Orn-βAcc-PEA, ; LA-Lys-βAcc-PEA, ; and LA-Arg-βAcc-PEA, in which a C12 lipid chain is conjugated at the N terminus of peptide through urea bonds. Further, we evaluated all the peptides against both and methicillin-resistant (MRSA) and their multidrug resistant (MDR) clinical isolates.
View Article and Find Full Text PDFRationally designed highly amphipathic antimicrobial peptides demonstrating superior bacterial selectivity relative to the corresponding α-helix peptide.
Eur J Med Chem
January 2025
Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, No. 1 Xian Nong Tan Street, Beijing, 100050, PR China; Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University, Lanzhou, 730000, PR China; Institute of Pharmaceutics, School of Pharmacy, 2019RU066, Lanzhou University, Lanzhou, 730000, PR China. Electronic address:
De novo design of antimicrobial peptides is a pivotal strategy for developing new antibacterial agents, leveraging its rapid and efficient nature. (XXYY), where X represents cationic residues, Y denotes hydrophobic residues, and n varies from 2 to 4, is a classical α-helix template. Based on which, numerous antimicrobial peptides have been synthesized.
View Article and Find Full Text PDFPeptide with Dual Roles in Immune and Metabolic Regulation: Liver-Expressed Antimicrobial Peptide-2 (LEAP-2).
Molecules
January 2025
College of Life Science, Liaoning Normal University, Dalian 116081, China.
Liver-expressed antimicrobial peptide 2 (LEAP-2) was originally discovered as an antimicrobial peptide that plays a vital role in the host innate immune system of various vertebrates. Recent research discovered LEAP-2 as an endogenous antagonist and inverse agonist of the GHSR1a receptor. By acting as a competitive antagonist to ghrelin, LEAP-2 influences energy balance and metabolic processes via the ghrelin-GHSR1a signaling pathway.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!