Pillay J, Ramakers BP, Kamp VM, Loi AL, Lam SW, Hietbrink F, Leenen LP, Tool AT, Pickkers P, Koenderman L, et al.
Journal of leukocyte biology. Date of publication 2010 Jul 1;volume 88(1):211-20.
1. J Leukoc Biol. 2010 Jul;88(1):211-20. doi: 10.1189/jlb.1209793. Epub 2010 Apr 16.
Functional heterogeneity and differential priming of circulating neutrophils in
human experimental endotoxemia.
Pillay J(1), Ramakers BP, Kamp VM, Loi AL, Lam SW, Hietbrink F, Leenen LP, Tool
AT, Pickkers P, Koenderman L.
Author information:
(1)Department of Respiratory Medicine, University Medical Center Utrecht,
Utrecht, The Netherlands.
Neutrophils play an important role in host defense. However, deregulation of
neutrophils contributes to tissue damage in severe systemic inflammation. In
contrast to complications mediated by an overactive neutrophil compartment,
severe systemic inflammation is a risk factor for development of immune
suppression and as a result, infectious complications. The role of neutrophils in
this clinical paradox is poorly understood, and in this study, we tested whether
this paradox could be explained by distinct neutrophil subsets and their
functionality. We studied the circulating neutrophil compartment immediately
after induction of systemic inflammation by administering 2 ng/kg Escherichia
coli LPS i.v. to healthy volunteers. Neutrophils were phenotyped by expression of
membrane receptors visualized by flow cytometry, capacity to interact with
fluorescently labeled microbes, and activation of the NADPH-oxidase by oxidation
of Amplex Red and dihydrorhodamine. After induction of systemic inflammation,
expression of membrane receptors on neutrophils, such as CXCR1 and -2 (IL-8Rs),
C5aR, FcgammaRII, and TLR4, was decreased. Neutrophils were also refractory to
fMLF-induced up-regulation of membrane receptors, and suppression of
antimicrobial function was shown by decreased interaction with Staphylococcus
epidermis. Simultaneously, activation of circulating neutrophils was demonstrated
by a threefold increase in release of ROS. The paradoxical phenotype can be
explained by the selective priming of the respiratory burst. In contrast, newly
released, CD16(dim) banded neutrophils display decreased antimicrobial function.
We conclude that systemic inflammation leads to a functionally heterogeneous
neutrophil compartment, in which newly released refractory neutrophils can cause
susceptibility to infections, and activated, differentiated neutrophils can
mediate tissue damage.
DOI: 10.1189/jlb.1209793
PMID: 20400675 [Indexed for MEDLINE]
