Polyreactive antigen-binding B cells are the predominant cell type in the newborn B cell repertoire.
Polyreactive antibodies bind to a variety of different self and non-self antigens. The B cells that make these antibodies express the polyreactive lg receptor on their surface. To determine the frequency of polyreactive antigen-binding B cells in peripheral blood, we incubated two different antigens, one (insulin) labeled with fluorescein isothiocyanate and the other (beta-galactosidase) with phycoerythrin, with peripheral B cells. The percentage of cells that bound these antigens was determined with the fluorescence-activated cells sorter. Approximately 21% of adult B cells bound insulin, 28% bound beta-galactosidase, and 11% bound both antigens. In contrast to B cells in the adult repertoire, 49% of B cells in cord blood bound insulin, 54% bound beta-galactosidase, and 33% bound both antigens. The properties of polyreactive antigen-binding B cells in adult and cord blood were similar, except for the fact that almost all the polyreactive antigen-binding B cells in cord blood were CD5 positive (93%), whereas only 40% of the polyreactive antigen-binding B cells in adult peripheral blood were CD5 positive, indicating that the CD5 marker is not directly linked to polyreactivity. The percentage of polyreactive antigen-binding B cells in patients with Sjögren's syndrome, systemic lupus erythematosus and rheumatoid arthritis was equal to or slightly below that found in the normal adult B cell repertoire. It is concluded that polyreactive antigen-binding B cells are a major constituent of the normal adult B cell repertoire and are the predominant cell type in the newborn B cell repertoire.
Chen
Z J
ZJ
Experimental Medicine Section, National Institute of Dental Research, National Institutes of Health, Bethesda, USA.
Wheeler
C J
CJ
Shi
W
W
Wu
A J
AJ
Yarboro
C H
CH
Gallagher
M
M
Notkins
A L
AL
D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D012859:Sjogren's Syndrome / Q000276:immunology