A novel cell surface antigen, 4C8, is expressed on human eosinophils.
BACKGROUND
A novel monoclonal antibody, anti-4C8, reacted with human peripheral lymphocytes and monocytes but not with neutrophils. In this study, we investigated whether the 4C8 antigen is expressed on human peripheral eosinophils.


METHODS
Expression of the 4C8 antigen on eosinophils was analyzed by flow cytometry and molecular analysis of the antigen was performed with eosinophils by Western blotting.


RESULTS
Among human peripheral granulocytes, the 4C8 antigen was expressed on CD16-negative cells but not on CD16-positive cells. The 4C8 antigen also appeared to be expressed on eosinophils. To confirm the latter finding, eosinophils were purified from peripheral blood. On flow cytometric analysis, anti-4C8 antibody reacted with purified eosinophils. On Western blotting analysis, anti-4C8 reacted with a single band of 80 kDa in lysates from purified eosinophils. The correlation between the percentage of eosinophils determined by May-Giemsa staining and the percentage of 4C8-positive/CD16-negative cells among granulocytes was good (r = 0.91, P < 0.0001).


CONCLUSIONS
Only a few cell surface antigens are available to distinguish human peripheral eosinophils from neutrophils. The novel cell surface antigen, 4C8, is a useful new marker of human eosinophils.
Aoyama
Yasutaka
Y
Department of Clinical Hematology, Osaka City University Medical School, Osaka, Japan.
Yamane
Takahisa
T
Hino
Masayuki
M
Ohta
Kensuke
K
Suzuki
Kenichi
K
Kitagawa
Seiichi
S
Masuyama
Jun-ichi
J
Tatsumi
Noriyuki
N
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D004804:Eosinophils / Q000737:chemistry* / Q000166:cytology; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008214:Lymphocytes / Q000737:chemistry; D009000:Monocytes / Q000737:chemistry; D009504:Neutrophils / Q000737:chemistry; D017452:Receptors, IgG / Q000032:analysis
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D017452:Receptors, IgG