Assay of Antibacterial Activities of the Bactericidal/Permeability-Increasing Protein in Natural Biological Fluids

All living organisms are constantly confronted by invading microbes. In mammals, host defense against microbial invasion requires specialized cellular and extracellular elements in blood and a complex signalling machinery that triggers their mobilization to extravascular sites of invasion in a highly regulated manner. This process is driven by microbe-specific signals, including highly conserved and chemically unique microbial (envelope) components, such as Gram-negative bacterial lipopolysaccharides (LPS) (1 ,2 ).