Cytotoxic effects of leukocidin from Pseudomonas aeruginosa on polymorphonuclear leukocytes from cattle

Abstract

The cytotoxic action of leukocidin from Pseudomonas aeruginosa was studied in vitro by following the release of various intracellular markers from polymorphonuclear leukocytes from cattle (PMLC). Low-molecular markers (K+, 86Rb+, glucose) were lost from PMLC within 1 to 2 min after the addition of leukocytes. The release of high-molecular-weight indicators (51Cr, bound to intracellular protein; lactate dehydrogenase) occurred only after swelling of the cells, leading to an increased permeability of the plasma membrane. Calcium ions stimulated the leakage of granule enzymes but retarded or inhibited the release of cytoplasmic markers. At 4 C, leukocytes were unaffected by the toxin. Leukocidin, bound at 4 C to leukocytes and treated with antiserum against leukocidin, did not damage the cells upon increasing the incubation temperature to 37 C.

Crystallization and Some Properties of Leukocidin from Pseudomonas aeruginosa

“…10, electron microscopy indicated an increase of vacuoles in the leukocidin-treated leukocytes. Accordingly, the toxic action of pseudomonal leukocidin may not be explained only by the production of lesions on the cell membrane as postulated by Scharmann (20), but may be related to cellular biochemical processes.…”

“…Preparation if leukocidin. P. aeruginosa 158 used in this study was shown to produce leukocidin by Scharmann (18)(19)(20)(21)(22) and kindly supplied by Lutz, Institute of Pharmacology and Toxicology, Justus-Lieberg-University. The microorganisms were grown on a trypticase soy broth medium containing 0.5% glucose with a reciprocal shaker (120 cycles/min) at 30 C for 12 hr.…”

“…Although most of our knowledge concerning the leukocidin of P. aeruginosa comes from the studies of Scharmann (18)(19)(20)(21)(22) and Lutz (11), the mode of cytotoxic action at the molecular level is still not understood. In the present paper, we described a procedure for purification and crystallization of pseudomonal leukocidin with good reproducibility differing from the method of Scharmann (18) and Lutz (11) based on solubilization of the toxin from its ammonium sulfate precipi ta te.…”

Biochemical and functional properties of a leucocidin produced by several strains of Fusobacterium necrophorum

“…Of the anaerobes, an extracellular cytotoxin with a n apparent MW of 3,500 has been obtained from Bacteroides gingivalis and B. asaccharolyticus but not B. melaninogenicus (van Steenbergen et a / 1982). Leucocidins assayed on bovine PBL include those produced by Pseudomonas aeruginosa (Scharmann 1976) and Pasfeureffa haemofytica (Baluyut et a/ 1981). The latter possesses biochemical and physical properties virtually identical to those described for F.necrophorum in the present study, in that it is a heat-labile protein, has a M W around 300,000, is inactivated by extremes of p H , especially acid p H , and is produced by P.haemo/ytica during logarithmic growth (Baluyut e t a / 1981).…”

Stimulation of Prostacyclin Production in Cultured Pulmonary Artery Endothelial Cells by Pseudomonas Aeruginosa Cytotoxin: Membrane Attack and Calcium Influx

“…No enzymatic activities are known for this protein and it probably acts primarily on the target cell membrane n u t z et Lutz, 1979). One of the first measurable effects of this toxin in the dose range of 1-50 pg/ml is a rapid increase in cell membrane permeability for ions and small molecules such as potassium, sodium, and glucose, but not for large molecules (Lutz et al, 1982;Maurer and Lutz, 1984;Scharmann, 1976). Therefore cytotoxin appears to create a n initially discrete transmembrane lesion.…”