CD177 polymorphisms: correlation between high-frequency single nucleotide polymorphisms and neutrophil surface protein expression.
BACKGROUND
Human neutrophil antigen-2a (NB1) is located on NB1 glycoprotein, which is expressed on subpopulations of neutrophils. PRV-1 is a gene that is over-expressed in neutrophils from patients with polycythemia rubra vera. The gene encoding NB1 differs from PRV-1 at four nucleotides. The purpose of this study was to determine if PRV-1 and NB1 are alleles of the same gene or two separate genes; and, moreover, if they are alleles, to explore potential correlations to NB1 glycoprotein expression.


METHODS
Primer pairs were used to amplify WBC DNA in the regions surrounding the four NB1 polymorphic sites. The four resulting amplicons were sequenced. The size of the neutrophil population in each donor that stained brightly with CD177 antibody was assessed by flow cytometry.


RESULTS
If PRV-1 and NB1 are separate genes, then all people should be heterozygous for the PRV-1/NB1 polymorphisms. Because 11 of 23 donors were homozygous for PRV-1 polymorphisms at all four sites, PRV-1 and NB1 are alleles of the same gene, CD177. When the sequenced exons were compared with PRV-1, 13 single nucleotide polymorphisms (SNPs) that result in amino acid changes were found. The G42C NB1 polymorphism, found in 10 donors, was the most common SNP. The size of the CD177 bright-staining neutrophil population was greater in 42C/C donors than in 42G/G donors (66 +/- 20% vs. 41 +/- 21%, p = 0.004).


CONCLUSIONS
PRV-1 and NB1 are alleles of the polymorphic gene CD177. The most common SNP in bp 42 predicted an amino acid change that may have an effect on protein expression.
Caruccio
Lorraine
L
Department of Transfusion Medicine, Warren G Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
Walkovich
Kelly
K
Bettinotti
Maria
M
Schuller
Randy
R
Stroncek
David
D
D001741:Black or African American / Q000235:genetics; D000483:Alleles; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence / Q000235:genetics; D002462:Cell Membrane; D003596:Cytosine; D058851:GPI-Linked Proteins; D005787:Gene Frequency; D005838:Genotype; D006147:Guanine; D006579:Heterozygote; D006801:Humans; D007519:Isoantigens / Q000235:genetics* / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D009504:Neutrophils / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011956:Receptors, Cell Surface; D013194:Staining and Labeling; D044465:White People / Q000235:genetics
D000954:Antigens, Surface; C407242:CD177 protein, human; D058851:GPI-Linked Proteins; D007519:Isoantigens; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D006147:Guanine; D003596:Cytosine