Diminished soluble and total cellular L-selectin in cord blood is associated with its impaired shedding from activated neutrophils.
We have previously shown that surface levels of the adhesive glycoprotein, L-selectin, are diminished on cord blood neutrophils (polymorphonuclear leukocytes, PMN) and associated with impaired adherence to endothelium under flow conditions. To test the hypothesis that diminished surface levels reflect a total cellular deficiency, we measured L-selectin in PMN lysates and plasma from cord and adult blood. L-selectin content was decreased in cord blood PMN lysates compared with those of adults by both Western blot analyses and ELISA (cord blood, 1195 +/- 160 pg/mL; adult, 1870 +/- 260 pg/mL; X +/- SEM; p < 0.05). Soluble L-selectin levels were also decreased in cord blood plasma (324 +/- 24 ng/mL versus 537 +/- 28 ng/mLiter in adult plasma, p < 0.01). To evaluate L-selectin function, we next compared the dose dependent effect of several chemoattractants on shedding of L-selectin from cord blood and adult PMN. Adult PMN showed greater overall shedding of L-selectin as compared with cord blood PMN after stimulation with fMet-Leu-Phe (p < 0.03) and granulocyte-macrophage colony-stimulating factor (p < 0.02). In contrast, shedding of L-selectin was similar between groups after IL-8 tested stimulation. We conclude that cord blood PMN have a decreased cellular content of L-selectin in addition to an impaired ability to shed surface L-selectin in response to specific inflammatory mediators.
Koenig
J M
JM
Section of Leukocyte Biology, Texas Children's Hospital, Houston, USA.
Simon
J
J
Anderson
D C
DC
Smith
E
E
Smith
C W
CW
D000328:Adult; D002478:Cells, Cultured; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000494:pharmacology; D006801:Humans; D007231:Infant, Newborn; D016209:Interleukin-8 / Q000494:pharmacology; D019041:L-Selectin / Q000097:blood*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*
D016209:Interleukin-8; D019041:L-Selectin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D016178:Granulocyte-Macrophage Colony-Stimulating Factor