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Am J Vet Res. 2000 May;61(5):492-8.

Role of inflammatory mediators in priming, activation, and deformability of bovine neutrophils.

Author information

1
Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St Paul 55180, USA.

Abstract

OBJECTIVE:

To determine the capacity of inflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), platelet-activating factor (PAF), lipopolysaccharide (LPS), and leukotoxin to prime, activate, or alter deformability of adult bovine neutrophils.

SAMPLE POPULATION:

Blood collected from 5 healthy adult Holstein cows.

PROCEDURE:

Isolated neutrophils or whole blood was incubated with TNF-alpha, IL-8, PAF, LPS, or leukotoxin, and neutrophil chemiluminescence, degranulation, deformability, shape change, CD11b expression, and size distribution was measured.

RESULTS:

Incubation with TNF-alpha, IL-8, PAF, and LPS primed neutrophils for oxygen radical release but caused minimal oxygen radical release by themselves. None of the inflammatory mediators induced degranulation. Incubation with TNF-alpha and PAF resulted in a decrease in neutrophil deformability and induced shape change in neutrophils. Incubation with PAF consistently resulted in an increase in neutrophil size as measured by use of flow cytometry. Only IL-8 caused an increase in expression of CD11b by neutrophils.

CONCLUSIONS AND CLINICAL RELEVANCE:

Inflammatory mediators tested had minimal effects on neutrophil oxygen radical production or degranulation but did prime neutrophils for oxygen radical production. Incubation with PAF and TNF-alpha caused a decrease in neutrophil deformability and altered neutrophil shape and size. Results of our study indicate that PAF- and TNF-alpha-induced changes in neutrophil deformability and size may cause integrin- and selectin-independent trapping of neutrophils in the lungs of cattle with pneumonic pasteurellosis.

PMID:
10803642
[Indexed for MEDLINE]

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