AJP - Lung Cellular and Molecular Physiology, Vol 267, Issue 6 786-L796, Copyright © 1994 by American Physiological Society
Monocytes recruited to sites of inflammation express a distinctive proinflammatory (P) phenotype
C. A. Owen, M. A. Campbell, S. S. Boukedes and E. J. Campbell
Department of Medicine, University of Utah Health Sciences Center, Salt Lake City 84132.
Only a minor proportion of monocytes responds to chemoattractants. To test
the possibility that chemoattractant-responsive monocytes have distinctive
functional characteristics, we enriched or depleted monocyte preparations
for cells having a proinflammatory (P) phenotype and tested their responses
to biologically relevant chemoattractants. We prepared monocyte
subpopulations by one of three independent techniques to minimize the
chances of artifacts: 1) depletion of P monocytes by adherence to
fibronectin; 2) enrichment for P monocytes by negative selection for HLA-DR
antigen; and 3) flow cytometric sorting. We measured responsiveness of
monocyte subpopulations to N-formyl-Met-Leu-Phe, C5a, zymosan-activated
serum, and monocyte chemoattractant protein-1 by three parameters: 1)
polarization, 2) actin polymerization, and 3) directed migration. With each
chemoattractant and each parameter, there was a striking direct
relationship between the responsiveness of the monocyte preparations and
their content of P monocytes. Our data indicate that the capacity of
monocytes to be recruited rapidly from the vasculature into sites of
inflammation is a property of a subpopulation of monocytes with a
distinctive, neutrophil-like proinflammatory phenotype.
