Cell surface expression of HFE protein in epithelial cells, macrophages, and monocytes.
OBJECTIVE
Most patients with hereditary hemochromatosis are homozygous for a Cys282AETyr mutation in the HFE gene. This mutation has been shown to impair the association of the HFE gene product with b(2)-microglobulin and to prevent its cell surface presentation in transfected COS-7 and 293 cells. This study was performed to examine the expression of HFE protein in epithelial cells, macrophages, and circulating leukocytes obtained from normal subjects and patients with hereditary hemochromatosis.


METHODS
Antisera against two different peptides of the HFE protein were used to immunostain tissue sections and isolate granulocytes, lymphocytes and monocytes.


RESULTS
Immunocytochemical staining showed that the HFE protein is expressed in gastric epithelial cells, tissue macrophages, and circulating monocytes and granulocytes. The cell surface associated signal, which was seen in normal gastric epithelial cells, monocytes and macrophages, was also present in C282Y mutant cells from patients with hereditary hemochromatosis, although at apparently reduced amounts in these cells.


CONCLUSIONS
From these studies, it is clear that the C282Y mutation reduces but does not completely prevent presentation of the HFE protein on the cell surface of human monocytes, tissue macrophages, and gastric epithelial cells.
Parkkila
S
S
Department of Anatomy and Cell Biology, University of Oulu, Box 5000, FIN-90401 Oulu, Finland. seppo.parkkila@oulu.fi.
Parkkila
A K
AK
Waheed
A
A
Britton
R S
RS
Zhou
X Y
XY
Fleming
R E
RE
Tomatsu
S
S
Bacon
B R
BR
Sly
W S
WS
D019943:Amino Acid Substitution; D004847:Epithelial Cells / Q000737:chemistry / Q000473:pathology; D005805:Genes, MHC Class I; D006680:HLA Antigens / Q000096:biosynthesis*; D006432:Hemochromatosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000737:chemistry / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D009000:Monocytes / Q000737:chemistry / Q000473:pathology; D017354:Point Mutation; D013194:Staining and Labeling; D013270:Stomach / Q000473:pathology
C103673:HFE protein, human; D006680:HLA Antigens; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins