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Quorum sensing contributes to activated IgM-secreting B cell homeostasis.

ABSTRACT: Maintenance of plasma IgM levels is critical for immune system function and homeostasis in humans and mice. However, the mechanisms that control homeostasis of the activated IgM-secreting B cells are unknown. After adoptive transfer into immune-deficient hosts, B lymphocytes expand poorly, but fully reconstitute the pool of natural IgM-secreting cells and circulating IgM levels. By using sequential cell transfers and B cell populations from several mutant mice, we were able to identify novel mechanisms regulating the size of the IgM-secreting B cell pool. Contrary to previous mechanisms described regulating homeostasis, which involve competition for the same niche by cells having overlapping survival requirements, homeostasis of the innate IgM-secreting B cell pool is also achieved when B cell populations are able to monitor the number of activated B cells by detecting their secreted products. Notably, B cell populations are able to assess the density of activated B cells by sensing their secreted IgG. This process involves the Fc?RIIB, a low-affinity IgG receptor that is expressed on B cells and acts as a negative regulator of B cell activation, and its intracellular effector the inositol phosphatase SHIP. As a result of the engagement of this inhibitory pathway, the number of activated IgM-secreting B cells is kept under control. We hypothesize that malfunction of this quorum-sensing mechanism may lead to uncontrolled B cell activation and autoimmunity.

SUBMITTER: Montaudouin C

PROVIDER: S-EPMC3572529 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

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Quorum sensing contributes to activated IgM-secreting B cell homeostasis.

Montaudouin Caroline C Anson Marie M Hao Yi Y Duncker Susanne V SV Fernandez Tahia T Gaudin Emmanuelle E Ehrenstein Michael M Kerr William G WG Colle Jean-Hervé JH Bruhns Pierre P Daëron Marc M Freitas António A AA

Journal of immunology (Baltimore, Md. : 1950) 20121203 1

Maintenance of plasma IgM levels is critical for immune system function and homeostasis in humans and mice. However, the mechanisms that control homeostasis of the activated IgM-secreting B cells are unknown. After adoptive transfer into immune-deficient hosts, B lymphocytes expand poorly, but fully reconstitute the pool of natural IgM-secreting cells and circulating IgM levels. By using sequential cell transfers and B cell populations from several mutant mice, we were able to identify novel mec ...[more]

PMID: 23209322

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Quorum sensing contributes to activated IgM-secreting B cell homeostasis.

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Quorum sensing contributes to activated IgM-secreting B cell homeostasis.

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