The acyl chain length, number, and distribution have been considered the major factors contributing to this biological activity of lipid A. The charged head groups on the dihexosamine backbone have also been implicated in contributing to this biology. In Neisseria, it has now been shown that loss of the 4' phosphoethanolamine has an impact on virulence in an animal model and on the organism's s...

To survive during colonization or infection of the human body, microorganisms must circumvent mechanisms of innate host defense. Antimicrobial peptides represent a key component of innate host defense, especially in phagocytes and on epithelial surfaces. However, it is not known how the clinically important group of Gram-positive bacteria sense antimicrobial peptides to coordinate a directed de...

Tuberculosis (TB) is a major worldwide health problem in part due to the lack of development of new treatments and the emergence of new strains such as multidrug-resistant (MDR) and extensively drug-resistant strains that are threatening and impairing the control of this disease. In this study, the efficacy of natural and synthetic cationic antimicrobial (host defence) peptides that have been s...

We used a template-assisted approach to develop synthetic antimicrobial peptides, which differ from naturally occurring antimicrobial peptides that can compromise host natural defenses. Previous researches have demonstrated that symmetrical distribution patterns of amino acids contribute to the antimicrobial activity of natural peptides. However, there is little research describing such design ...

Cationic antimicrobial peptides are major components of innate immunity and help control the initial steps of the infectious process. They are expressed not only by immunocytes, but also by epithelial cells. They share an amphipathic secondary structure with a polar cationic site, which explains their tropism for prokaryote membranes and their hydrophobic site contributing to the destructuratio...

Antimicrobial peptides (AMPs) have been an area of great interest, due to the high selectivity of these molecules toward bacterial targets over host cells and the limited development of bacterial resistance to these molecules throughout evolution. The peptide C18G has been shown to be a selective, broad spectrum AMP with a net +8 cationic charge from seven lysine residues in the sequence. In th...

Natural antimicrobial peptides (AMPs) are small cationic molecules that display antimicrobial activity against a wide range of bacteria, fungi and viruses. AMPs are multifunctional molecules that have an essential activity in infection and inflammation: they play an important role in the innate immune response, not only as antimicrobial agents, but also as immunomodulating molecules and as an i...

There is an urgent need for new antibiotics which are effective against drug-resistant bacteria without contributing to resistance development. We have designed and developed antimicrobial copolymers with cationic amphiphilic structures based on the mimicry of naturally occurring antimicrobial peptides. These copolymers exhibit potent antimicrobial activity against a broad spectrum of bacteria ...

Host-defense peptides (HDPs) are produced by eukaryotes to defend against bacterial infection, and diverse synthetic polymers have recently been explored as mimics of these natural peptides. HDPs are rich in both hydrophobic and cationic amino acid residues, and most HDP-mimetic polymers have therefore contained binary combinations of hydrophobic and cationic subunits. However, HDP-mimetic poly...

Many neuropeptides and peptide hormones are very similar to antimicrobial peptides in their amino acid composition, amphipathic design, cationic charge and size. Their antimicrobial activities suggest they may also be directly involved in innate defense. Here we discuss recent advances in understanding how the mammalian nervous system, equipped with neuropeptides and peptide hormones with poten...