Antigen-binding B cells and polyreactive antibodies.
The present experiments were initiated to see if cells capable of binding antigens could make polyreactive antibodies. Fluorescein isothiocyanate-labeled self and non-self antigens were incubated with B cells from normal individuals. Antigen-binding cells were separated from non-antigen-binding cells by flow cytometry, immortalized with Epstein-Barr virus and analyzed at the clonal level for their capacity to make polyreactive antibodies. Four to six times more cells making polyreactive antibodies were found in the B cell subset that bound antigens than in the B cell subset that did not bind antigens. The majority of the polyreactive antibodies were of the immunoglobulin (Ig)M isotype. Immunoflow cytometry revealed that cell lines making polyreactive antibodies bound a variety of antigens (e.g., insulin, IgGFc and beta-galactosidase), whereas cell lines making monoreactive antibodies bound only a single antigen. The binding of antigens to B cell lines that made polyreactive antibodies could be inhibited (range, 28%-57%) by both homogeneous and heterogeneous antigens. Both CD5+ and CD5- antigen-binding B cells made polyreactive antibodies, but the frequency was slightly higher in the CD5+ antigen-binding (85%) as compared to the CD5- antigen-binding (50%) population. Comparison of CD5+ B cells that bound antigens with CD5+ B cells that did not bind antigens showed that approximately 86% of the former, but only 15% of the latter, made polyreactive antibodies. It is concluded that cells capable of binding a variety of different antigens can make polyreactive antibodies and that antigen binding is a good marker for identifying polyreactive antibody-producing cells.
Chen
Z J
ZJ
Laboratory of Oral Medicine, National Institute of Dental Research, National Institutes of Health, Bethesda 20892.
Wheeler
J
J
Notkins
A L
AL
D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D018956:CD5 Antigens; D006801:Humans; D007328:Insulin / Q000276:immunology; D017452:Receptors, IgG / Q000276:immunology; D001616:beta-Galactosidase / Q000276:immunology
D000941:Antigens; D015703:Antigens, CD; D018956:CD5 Antigens; D007328:Insulin; D017452:Receptors, IgG; D001616:beta-Galactosidase