Human Host Defense Peptides - Role in Maintaining Human Homeostasis and Pathological Processes

The human body expresses over 100 host defense peptides and proteins (antimicrobial peptides, AMPs). The compounds are produced by tissues and mucosal surfaces, e.g. skin, the digestive and urinary tract, the ocular surface and neutrophils, and are believed to play a crucial role in defense from microbial infection. They are considered to protect the human body against microbial infections due to their antimicrobial and immunomodulatory activities. As well as having strong antimicrobial activity towards a broad spectrum of microorganisms, AMPs have been found to interact with neutrophils, monocytes and T-cells and promote the production of cytokines. They also neutralize the action of lipopolysaccharide (LPS) and play a crucial role in wound healing processes. Keywords: Antimicrobial peptides, cathelicidin, defensins, psoriasis, atopic dermatitis, cystic fibrosis, chronic obstructive pulmonary disease, periodontitis, arthritis, atherosclerosis.