All issues > Volume 45(5); 2002

Original Article

J Korean Pediatr Soc. 2002;45(5):637-645. Published online May 15, 2002.

A Study of Receptor Expression in Leukocytes by Quantitative Fluorescence Measurement

Kyung Hyo KH Kim¹, Ju Young JY Seoh²

¹Department of Pediatrics, College of Medicine, Ewha Woman's University, Seoul, Korea
²Department of Microbiology, College of Medicine, Ewha Woman's University, Seoul, Korea

Correspondence Kyung Hyo KH Kim ,Tel: 02)760-5127, Fax: 02)765-385, Email: kaykim@mm.ewha.ac.kr

Abstract

Purpose
: It is well known that the receptors for Fcγ moiety of IgG(FcγR) are instrumental in antibody-mediated clearance of microorganisms by granulocytes and monocytes, and immune regulation in lymphocytes. Furthermore, complement receptor-3(CR3) is also important in neutrophilic adhesion, diapedesis, and phagocytic functions. In an attempt to examine their roles in neonates, we compared the expressions of FcγRs and CR3 in cord blood leukocytes with those expressed in leukocytes in samples of blood obtained from adult subjects.
Methods
: Cord blood was obtained from 30 full-term newborn and peripheral blood from 30 adult volunteers. In both groups, we measured three Fcγ receptors and one adhesion molecule, CR3 on granulocytes, monocytes and lymphocytes using a whole blood method with flow cytometry and quantitative bead standards to enumerate the cell surface receptors.
Results
: Compared to those observed in adult blood, the proportions of FcγRI＋ granulocytes were significantly higher in cord blood. By contrast, the proportions of FcγRII＋ or FcγRIII＋ granulocytes and the number of FcγRIII were significantly lower in cord blood. The proportions of FcγRI＋, FcγRII＋, and CD18＋ bearing monocytes and the number of FcγRII in lymphocytes were also significantly lower in cord blood as compared to adult blood.
Conclusion
: There were differences in the proportions of cells expressing FcγRs and CR3 and in the number of FcγRs and CR3 in granulocytes, monocytes, and lymphocytes between cord blood and peripheral blood from adult subjects. These may contribute to the difference in immune capability that is known to exist between neonates and adult subjects.

Keywords :Fcγ receptor, CR3, Leukocyte