Contents

Bactericidal permeability-increasing protein

Bactericidal permeability-increasing protein (BPI) is a 456-residue (~50kDa) protein that is part of the innate immune system, coded for in the human by the BPI gene.^[1][2] It belongs to the family of lipid-binding serum glycoproteins.

Distribution and function[edit]

BPI was initially identified in neutrophils, but is found in other tissues including the epithelial lining of mucous membranes.^[3] It is an endogenous antibiotic protein with potent killing activity against Gram-negative bacteria. It binds to compounds called lipopolysaccharides produced by Gram-negative bacteria. Lipolysaccharides are potent activators of the immune system; however, BPI at certain concentrations can prevent this activation.

BPI was discovered by Jerrold Weiss and Peter ElsbachatNew York University Medical School.

rBPI₂₁[edit]

Because lipopolysaccharides are potent inflammatory agents, and the action of antibiotics can result in the release of these compounds, the binding capacity of BPI was explored as a possible means of reducing injury. Xoma Ltd. developed a recombinant 21kDa portion of the BPI molecule called rBPI₂₁, NEUPREX, or opebecan. In a trial, it was found to decrease the mortality of Gram-negative bacterial-induced sepsis.^[4] Studies suggest that its binding activity is not the means by which it mediates its protective effect.^[5] Studies show biological effects with Gram-positive bacteria^[6] and even in infection by the protozoan, Toxoplasma gondii.^[7]

The N-terminal portion of murine BPI (199 amino acids) genetically fused to Halobacterium sp. NRC-1 GvpC protein was bound to the surface of gas vesicle nanoparticles (GVNPs) and tested for protective activity using a murine model of endotoxic shock. Depending on the time of delivery and exposure to lethal concentrations of lipopolysaccharide (LPS) and D-galactosamine, the treatment resulted in increased survival and reduced symptoms of inflammation, including inflammatory anemia, recruitment of neutrophils, liver apoptosis as well as increased pro-inflammatory serum cytokine levels. When administered via footpad and before LPS exposure, there was 100% survival of the experimental cohort.^[8]

References[edit]

External links[edit]

• bactericidal+permeability+increasing+protein at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

This article on a gene on human chromosome 20 is a stub. You can help Wikipedia by expanding it.