Anti-DNA antibody production by CD5+ and CD5- B cells of patients with systemic lupus erythematosus.
Although the presence of anti-DNA antibody is a hallmark of systemic lupus erythematosus (SLE), neither the subsets of B cells that secrete anti-DNA antibody nor the stimuli responsible for the induction of anti-DNA secretion is known. In particular, the role of CD5+ B cells in human SLE, a distinct subpopulation of antibody-secreting cells shown previously to be a source of anti-DNA antibody in murine models of SLE, is unknown. To approach these questions, we developed a sensitive enzyme-linked immunospot (ELIspot) assay to measure spontaneous secretion of antibody to single-stranded (ss) DNA, double-stranded (ds) DNA, tetanus toxoid, and polyclonal immunoglobulin (Ig) by purified CD5+ and CD5- B cells of 15 SLE patients and 15 healthy control subjects. The B cells of only 1 of 15 healthy subjects secreted a significant level of anti-ssDNA antibody, and none secreted anti-dsDNA. By contrast, in the majority of SLE patients both CD5+ and CD5- B cells secreted IgG and/or IgM anti-ssDNA as well as anti-dsDNA antibody. Further analysis of the anti-ssDNA response revealed that the level of IgG and IgM anti-DNA antibody secretion by CD5- B cells correlated closely with the level of polyclonal Ig production by the same subpopulation (r = 0.81 and 0.70, respectively). In contrast, production of anti-DNA by CD5+ B cells occurred independently of polyclonal Ig production by both CD5+ and CD5- B cell subpopulations. These results suggest that in human SLE there exist two anti-DNA antibody-producing B cell subpopulations with distinct induction mechanisms: one (CD5+), which independently secretes anti-DNA, and another (CD5-), which produces anti-DNA as an apparent consequence of polyclonal B cell activation.
Suzuki
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N
Department of Pathology, Stanford University, California 94305.
Sakane
T
T
Engleman
E G
EG
D000328:Adult; D000917:Antibody Formation; D015703:Antigens, CD / Q000032:analysis*; D000943:Antigens, Differentiation / Q000032:analysis*; D001323:Autoantibodies / Q000032:analysis / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018956:CD5 Antigens; D002469:Cell Separation; D004277:DNA, Single-Stranded / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation; D008875:Middle Aged
D015703:Antigens, CD; D000943:Antigens, Differentiation; D001323:Autoantibodies; D018956:CD5 Antigens; D004277:DNA, Single-Stranded; D007074:Immunoglobulin G; D007075:Immunoglobulin M