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Heterogeneity in F‐actin polymerization of cord blood polymorphonuclear leukocytes stimulated by N ‐ formyl‐ methionyl‐leucyl‐phenylalanine
Author(s) -
Hasui SHOICHIRO TANIUCHI, YO KINOSHITA, AKEMI YAMAMOTO, TORU FUJIWARA, KAZUHIRO HATTORI, MASASHI,
Kobayashi YOHNOSUKE
Publication year - 1999
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1046/j.1442-200x.1999.01017.x
Subject(s) - medicine , phenylalanine , cord blood , polymerization , immunology , microbiology and biotechnology , biochemistry , organic chemistry , amino acid , polymer , chemistry , biology
Background: To elucidate the mechanism responsible for defects of polymorphonuclear leukocyte (PMNL) chemotaxis of neonates, we determined actin polymerization of NBD (7‐nitrobenz‐2‐oxa‐diazol)‐phallacidin‐stained PMNL following stimulation with either N ‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) or phorbol myristate acetate (PMA) in cord blood and adult controls. Methods : We measured F‐actin content in PMNL stained with NBD‐phallacidin using flow cytometry. Results : Relative F‐actin polymerization, that is, a ratio of stimulated F‐actin to basal F‐actin, was significantly decreased in cord blood PMNL when compared with that of adult PMNL. Distribution of fMLP‐stimulated F‐actin showed a bimodal pattern, while adult PMNL disclosed a single pattern. Following stimulation with PMA, however, F‐actin levels were equal in both cord and adult PMNL. A fluorescein isothiocyanate‐conjugated fMLP receptor assay showed no significant difference in binding capacity of fMLP receptors between adult and cord PMNL. Conclusion : These results indicate that a deficiency of PMNL chemotaxis in neonates may be due, in part, to decreased relative F‐actin polymerization, which may be caused by functional heterogeneity in cord blood PMNL.