The double life of a B-1 cell: self-reactivity selects for protective effector functions

  title={The double life of a B-1 cell: self-reactivity selects for protective effector functions},
  author={Nicole Baumgarth},
  journal={Nature Reviews Immunology},
During their development, B and T cells with self-reactive antigen receptors are generally deleted from the repertoire to avoid autoimmune diseases. Paradoxically, innate-like B-1 cells in mice are positively selected for self-reactivity and form a pool of long-lived, self-renewing B cells that produce most of the circulating natural IgM antibodies. This Review provides an overview of the developmental processes that shape the B-1 cell pool in mice, outlines the functions of B-1 cells in both… 

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B-1 cell responses to infections.

B-1 Cell Heterogeneity and the Regulation of Natural and Antigen-Induced IgM Production

This review considers three factors that may contribute to functional heterogeneity among innate-like B cells: first, developmental differences regarding the origins of the precursors, second, tissue-specific signals that may differentially affect B-1 cells in the tissue compartments, and finally responsiveness to self-antigens as well as innate and antigen- specific signals.

B-1a cells acquire their unique characteristics by bypassing the pre-BCR selection stage

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Innate-like B cells and their rules of engagement.

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  • Biology
    Advances in experimental medicine and biology
  • 2013
B-1 cells, an innate-like B cell population distinct in development, repertoire, and tissue location from the majority conventional or B-2 cells, are the main contributors of natural antibodies in mice in steady state, and recent data show that natural IgM production appears largely confined to B-1 cell populations in the spleen and bone marrow.

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An unexpected and distinct role for sIgM is demonstrated in the control of autoreactive B cells: the regulation of bone marrow B cell development and this finding strongly suggests that IgM is critical for B-cell central tolerance induction.

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The factors that are important for Breg differentiation and for their effector function in both mouse and human are discussed.

CTLA-4 expression by B-1a B cells is essential for immune tolerance

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A murine model system of naturally generated autoreactive B cells with a germ line gene-encoded specificity for the Thy-1 (CD90) glycoprotein was developed, in which the presence of self-antigen promotes B cell accumulation and serum autoantibody secretion.

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The prevalence of self-reactive antibody formation and its regulation in human B cells is determined and a majority (55 to 75%) of all antibodies expressed by early immature B cells displayedSelf-reactivity, including polyreactive and anti-nuclear specificities.

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  • Biology, Medicine
    Current opinion in immunology
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Autoimmunity-prone B-1 (CD5 B) cells, natural antibodies and self recognition.

The recent findings suggest that while in healthy subjects the majority of natural polyreactive antibodies is encoded in V genes in germline configuration, some polyre active antibodies are encoded in somatically mutated V genes, in a fashion consistent with an antigen-driven process of selection of such mutations.

B-1 cells modulate oral tolerance in mice.

Origins and functions of B-1 cells with notes on the role of CD5.

Evidence indicates that B-1a cells can derive from adult precursors expressing an appropriate specificity when the (self-) antigen is present, and the CD5 molecule can function as a negative regulator of BCR signaling that may help prevent inappropriate activation of autoreactive B- 1a cells.

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