|
|
 Previous Article | Table of Contents | Next Article 
Oxidative mechanisms utilized by human neutrophils to destroy Escherichia
coli
SA Passo and SJ Weiss
Serum-opsonized bacteria are efficiently ingested and killed by neutrophils
within the phagocytic vacuole, where they are exposed to an array of
reactive oxygen metabolites and toxic lysosomal components. Although
bacteria may be destroyed by oxygen-independent mechanisms alone, many
types of bacteria are not killed effectively unless they are attacked by
oxygen metabolites. However, the apparent inability of extracellular
scavengers, or inhibitors, of oxygen metabolites to gain access to the
phagocytic vacuole makes this system difficult to evaluate. Therefore, we
investigated the ability of neutrophils triggered with phorbol myristate
acetate to destroy unopsonized E. coli in a serum-free model system.
Neutrophils incubated with phorbol myristate acetate at a cell-to-bacteria
ratio of 1:4 caused a greater than 95% reduction in colony-forming units
(CFU) of E. coli in 60 min at 37 degrees C. Destruction of E. coli by the
stimulated neutrophils was dependent on neutrophil number, stimuli
concentration, and the incubation period. The neutrophil-mediated
bactericidal effect was stimulated by superoxide dismutase, but was
inhibited by catalase, azide, or compounds known to scavenge hypochlorous
acid. Although stimulated neutrophils can generate long-lived endogenous N-
chloroamines , these compounds did not play a direct role in destruction of
E. coli in our model system. However, in the presence of exogenous iodide,
endogenous N- chloroamines exerted a powerful bactericidal effect. Finally,
neutrophils triggered with opsonized zymosan could also mediate E. coli
destruction by a qualitatively similar process. Thus, we have demonstrated
that neutrophils have the potential to utilize the myeloperoxidase system
to generate bactericidal quantities of a species with characteristics
similar to, if not identical with, hypochlorous acid.
Volume 63,
Issue 6,
pp. 1361-1368,
06/01/1984
Copyright © 1984 by The American Society of Hematology
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati What's this?
This article has been cited by other articles:
|
|
|
|
 
A. M. Cantin, G. Bilodeau, C. Ouellet, J. Liao, and J. W. Hanrahan
Oxidant stress suppresses CFTR expression
Am J Physiol Cell Physiol,
January 1, 2006;
290(1):
C262 - C270.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Nagl, M. W. Hess, K. Pfaller, P. Hengster, and W. Gottardi
Bactericidal Activity of Micromolar N-Chlorotaurine: Evidence for Its Antimicrobial Function in the Human Defense System
Antimicrob. Agents Chemother.,
September 1, 2000;
44(9):
2507 - 2513.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
S. Weiss, S. Test, C. Eckmann, D Roos, and S Regiani
Brominating oxidants generated by human eosinophils
Science,
October 10, 1986;
234(4773):
200 - 203.
[Abstract]
[PDF]
|
|
|
|
|
