Bactericidal activity of fractionated granule contents from human polymorphonuclear leukocytes

Abstract

Proteins from human polymorphonuclear leukocyte granules were extracted with 0.2 M acetate, pH 4.0, and fractionated by Sephadex G-100 column chromatography. The fractions demonstrated selective bactericidal action against a deep rough cell wall mutant of Escherichia coli O111:B4 with rough lipopolysaccharide [LPS] and cell wall mutants of Salmonella typhirmurium LT-2 with LPS of Ra, Rc, Rd1, Rd2 and Re types. Smooth parent strains were most resistant to the bactericidal action. Fractions with greatest activity for the mutants were from valley regions (regions of low protein concentration) between 3 high protein peaks comprising myeloperoxidase, protease and lysozyme, respectively. Susceptibility of the mutants to bactericidal action increased as sugar residues decreased in LPS. Gram-positive bacteria were susceptible to different fractions than were the gram-negative bacteria.