The effect of interleukin-6 on L-selectin levels on polymorphonuclear leukocytes.
Interleukin-6 (IL-6) shortens the transit time of polymorphonuclear leukocytes (PMN) through the marrow and accelerates their release into the circulation. In contrast to other inflammatory stimuli, this response is associated with a decrease in L-selectin levels on circulating PMN. The present study was designed to determine the effect of IL-6 on L-selectin levels of PMN in rabbits. Recombinant human IL-6 (2 microg/kg) caused a decrease in L-selectin levels on circulating PMN 3 to 12 h after treatment (P < 0.05). L-selectin levels decreased on PMN already in the circulation for up to 4 h (P < 0.05), on PMN released from the marrow posttreatment for up to 12 h (P < 0.01) and on PMN in the marrow for up to 6 h (P < 0.05) after IL-6 treatment. We conclude that IL-6 decreases L-selectin levels on circulating PMN by demarginating PMN with low levels of L-selectin and by releasing PMN from the marrow with low levels of L-selectin. We postulate that this prolonged downregulation of L-selectin on circulating PMN could influence their recruitment into inflammatory sites.
McDonald Research Laboratory and iCAPTURE Centre, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada V6Z 1Y6.
Tatsushi
T
Suwa
James C
JC
Hogg
Kevin B
KB
Quinlan
Stephan F
SF
Van Eeden
D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000494:pharmacology*; D019041:L-Selectin / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism*; D011817:Rabbits
D015850:Interleukin-6; D019041:L-Selectin