title: Autoantigen-B cell antigen receptor interactions that regulate expression of B cell antigen receptor Loci.
abstract: Levels of AgR (BCR) expression are regulated during B cell development, activation, and induction of tolerance. The mechanisms responsible for and consequences of this regulation are poorly understood. We have described a class of DNA-based autoantigen-reactive B cell that down-regulates BCR expression during development to mature follicular phenotype. In this study, we show that at immature stages of primary differentiation, individual B cells of this type can dynamically modulate levels of expression of BCR in inverse proportion to degree of autoantigen engagement and induced BCR signaling. These adjustments in BCR expression are not associated with cell death, BCR revision, or altered development, and do not require TLR 9. Strikingly, modulation of BCR subunit gene RNA levels and transcription parallels these changes in BCR expression, indicating a direct link between autoantigen-BCR interactions of this type and regulation of transcription of BCR-encoding loci. We propose that this adaptive process allows this class of autoreactive B cell to avoid conventional tolerance pathways and promotes development to mature phenotype.
authors.affiliation: Department of Microbiology and Immunology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Xiaohe
authors.initials: X
authors.lastname: Liu
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Wysocki
authors.forename: Tim
authors.initials: T
authors.lastname: Manser
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000502:physiology*; D001402:B-Lymphocytes / Q000502:physiology; D001854:Bone Marrow Cells / Q000502:physiology; D020013:Calcium Signaling; D004705:Endocytosis; D005786:Gene Expression Regulation; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007075:Immunoglobulin M / Q000032:analysis / Q000378:metabolism; D007135:Immunoglobulin Variable Region / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D011947:Receptors, Antigen, B-Cell / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D051217:Toll-Like Receptor 9 / Q000502:physiology; D014158:Transcription, Genetic
chemical_list: D001324:Autoantigens; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D011947:Receptors, Antigen, B-Cell; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9