title: Characterization of anergic anti-DNA B cells: B cell anergy is a T cell-independent and potentially reversible process.
abstract: Anti-single stranded DNA (ssDNA) and anti-double stranded DNA (dsDNA) B cells are regulated in non-autoimmune mice. In this report we show that while both anti-ssDNA and anti-dsDNA B cells are blocked in their ability to differentiate into antibody-secreting cells, other phenotypic and functional characteristics distinguish them from one another. Splenic anti-ssDNA B cells are found distributed throughout the B cell follicle, and are phenotypically mature and long-lived. On the other hand, splenic anti-dsDNA B cells are short-lived, exhibit an immature and antigen-experienced phenotype, and localize to the T-B interface of the splenic follicle. Functionally, anti-ssDNA B cells proliferate, albeit suboptimally, in response to anti-IgM, lipopolysaccharide (LPS) and CD40L/IL-4 + anti-IgM stimulation, and tyrosine phosphorylate intracellular proteins upon mIgM cross-linking. Anti-dsDNA B cells, on the other hand, are functionally unresponsive to anti-IgM and LPS stimulation, and do not phosphorylate intracellular proteins, including Syk, upon mIg stimulation. Importantly, anti-DNA B cell anergy is maintained in the absence of T cells since both anti-ssDNA and anti-dsDNA B cells are as efficiently regulated in RAG2(-/-) mice as in their RAG2(+/+) counterparts. Interestingly, the severely anergic state of anti-dsDNA B cells is partially reversible upon stimulation with CD40 ligand and IL-4. In response to these signals, anti-dsDNA B cells remain viable, up-regulate cell surface expression of B7-2 and IgM, and restore their ability to proliferate and phosphorylate Syk upon mIg cross-linking. Collectively, these data suggest that anti-DNA B cell anergy encompasses distinct phenotypes which, even in its most severe form, may be reversible upon stimulation with T cell-derived factors.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D000921:Antibody-Producing Cells / Q000502:physiology; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand; D004247:DNA / Q000276:immunology*; D015847:Interleukin-4 / Q000494:pharmacology; D051917:Leukosialin; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010766:Phosphorylation; D012795:Sialoglycoproteins / Q000032:analysis; D013601:T-Lymphocytes / Q000502:physiology*