ACTIVATION OF NEUTROPHIL FUNCTIONS BY
CYTOKINES AND THEIR RECEPTORS EXPRESSION ON NEUTROPHILS IN NEONATES
Moriguchi N,
Yamamoto S, Miyata H, Yoshioka K
Kinki University
School of Medicine, Department of Pediatrics, Japan
Objective: The aim of study was to investigate
the difference and mechanism of neutrophils activation by granulocyte
colony stimulating factor (GCS-F), granulocyte -macrophage colony
stimulating factor (GM-CSF), or tumor necrosis factor-alpha (TNF), between
neonates and adult controls.
Methods: Neutrophils were from the cord blood
of term neonates (n=41) and from the peripheral blood of healthy adult
controls (n=20). The protease (elastase, collagenase, cathepsin) activity
in neutrophils was measured using Rhodamine based compouds with flowcytometry.
The expression of adhesion molecules (CD11b , L-selectin), or receptors of GCS-F,
GM-CSF, TNF on neutrophils was also measured with flowcytometry. Neutrophis
were incubated by GCS-F , GMCS-F, or TNF, and the changes of neutrophil
functions (intracellular protease activity, surface expression of adhesion
molecules ) were studied.
Results: When stimulated by G-CSF, GM-CSF, or
TNF, the degree of enhanced intracellar elastase and collagenase activity,
CD11b up and L-selectin down regulation on cell surface of neutrophils were
less in term neonates. G-CSF, GM-CSF receptors on neutrophils in neonates
were significantly lower than adult controls (either p<0.01).
Conclusion:
The lower levels of G-CSF, GM-CSF receptors on neonatal neutrophils may cause
a reduced biological response.