Mechanism of CD11b down-regulation from phorbol myristate acetate stimulated polymorphonuclear neutrophils.
OBJECTIVE
To investigate the mechanism of CD11b down-regulation in phorbol myristate acetate (PMA) stimulated polymorphonuclear leukocytes (PMN).


METHODS
Purified PMN were stimulated with PMA in the presence, or absence, of various enzyme inhibitors. Following stimulation, PMN CD11b expression was examined by flow cytometry and Western-blotting. The entire work was carried out at Liverpool University between the period of 1998 and 2001.


RESULTS
Stimulation of PMN with PMA induced the down-regulation of CD11b by a mechanism involving a combination of an oxidant and a serine protease; most likely the primary granule derived elastase.


CONCLUSIONS
The present study shows for the first time the cooperation of both oxidants and enzymes in the down-regulation of PMN adhesion receptors.
Aziz
Khalil A
KA
Regional Department of Immunology, Heart of England NHS Foundation, Birmingham, United Kingdom. khalilazizh@yahoo.co.uk
D039481:CD11b Antigen / Q000032:analysis / Q000276:immunology*; D002478:Cells, Cultured; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology*; D008297:Male; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*; D012307:Risk Factors; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D039481:CD11b Antigen; D013755:Tetradecanoylphorbol Acetate