Rac2 concentrations in umbilical cord neutrophils.
BACKGROUND
Human newborn infants display a variety of immunodeficiencies of immaturity, including diminished neutrophil adhesion, chemotaxis, and migration. Rac2, a guanosine triphosphate-binding protein, is an essential regulator of human neutrophil migration and chemotaxis. Since human subjects and mice deficient in Rac2 display deficiencies in neutrophil functions similar to newborn infants, we postulated that newborn neutrophils may be deficient in Rac2.


OBJECTIVE
The aim of the study was to measure Rac1 and Rac2 concentrations in neutrophils from umbilical cord blood.


METHODS
Neutrophils from cord and adult blood were isolated, total cell lysates extracted, and Rac protein concentrations determined using Western blot analysis.


RESULTS
Rac2 concentrations were significantly lower in the neutrophil protein lysates isolated from cord blood compared to adult blood despite similar levels of Rac1.


CONCLUSIONS
Diminished Rac2 expression in cord blood neutrophils may contribute to the defects observed in cord blood neutrophil function.
Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Virginia M
VM
Meade
Cecilia N
CN
Barese
Chaekyun
C
Kim
Charles G
CG
Njinimbam
Christophe C
CC
Marchal
David A
DA
Ingram
D Wade
DW
Clapp
Mary C
MC
Dinauer
Mervin C
MC
Yoder
D000375:Aging; D015153:Blotting, Western; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D009504:Neutrophils / Q000737:chemistry* / Q000502:physiology; D012016:Reference Values; D020744:rac GTP-Binding Proteins / Q000097:blood*; D020830:rac1 GTP-Binding Protein / Q000097:blood; D000097766:RAC2 GTP-Binding Protein
D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D000097766:RAC2 GTP-Binding Protein; C107953:RAC1 protein, human