title: Actin-mediated feedback loops in B-cell receptor signaling.
abstract: Upon recognizing cognate antigen, B cells mobilize multiple cellular apparatuses to propagate an optimal response. Antigen binding is transduced into cytoplasmic signaling events through B-cell antigen receptor (BCR)-based signalosomes at the B-cell surface. BCR signalosomes are dynamic and transient and are subsequently endocytosed for antigen processing. The function of BCR signalosomes is one of the determining factors for the fate of B cells: clonal expansion, anergy, or apoptosis. Accumulating evidence underscores the importance of the actin cytoskeleton in B-cell activation. We have begun to appreciate the role of actin dynamics in regulating BCR-mediated tonic signaling and the formation of BCR signalosomes. Our recent studies reveal an additional function of the actin cytoskeleton in the downregulation of BCR signaling, consequently contributing to the generation and maintenance of B-cell self-tolerance. In this review, we discuss how actin remodels its organization and dynamics in close coordination with BCR signaling and how actin remodeling in turn amplifies the activation and subsequent downregulation process of BCR signaling, providing vital feedback for optimal BCR activation.
authors.affiliation: Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, USA.
authors.forename: Wenxia
authors.initials: W
authors.lastname: Song
authors.forename: Chaohong
authors.initials: C
authors.lastname: Liu
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Seeley-Fallen
authors.forename: Heather
authors.initials: H
authors.lastname: Miller
authors.forename: Christina
authors.initials: C
authors.lastname: Ketchum
authors.forename: Arpita
authors.initials: A
authors.lastname: Upadhyaya
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D025461:Feedback, Physiological; D006801:Humans; D011485:Protein Binding; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000199:Actins; D011947:Receptors, Antigen, B-Cell
keywords: B cells; B-cell antigen receptor; actin cytoskeleton; endocytosis; signal transduction