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Rey-Suarez I, Wheatley BA, Koo P, Bhanja A, Shu Z, Mochrie S, Song W, Shroff H, Upadhyaya A. WASP family proteins regulate the mobility of the B cell receptor during signaling activation. Nat Commun 2020; 11:439. [PMID: 31974357 PMCID: PMC6978525 DOI: 10.1038/s41467-020-14335-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 12/23/2019] [Indexed: 12/13/2022] Open
Abstract
Regulation of membrane receptor mobility tunes cellular response to external signals, such as in binding of B cell receptors (BCR) to antigen, which initiates signaling. However, whether BCR signaling is regulated by BCR mobility, and what factors mediate this regulation, are not well understood. Here we use single molecule imaging to examine BCR movement during signaling activation and a novel machine learning method to classify BCR trajectories into distinct diffusive states. Inhibition of actin dynamics downstream of the actin nucleating factors, Arp2/3 and formin, decreases BCR mobility. Constitutive loss or acute inhibition of the Arp2/3 regulator, N-WASP, which is associated with enhanced signaling, increases the proportion of BCR trajectories with lower diffusivity. Furthermore, loss of N-WASP reduces the diffusivity of CD19, a stimulatory co-receptor, but not that of FcγRIIB, an inhibitory co-receptor. Our results implicate a dynamic actin network in fine-tuning receptor mobility and receptor-ligand interactions for modulating B cell signaling. B cell receptors (BCR) capture antigen and initiate downstream antibody responses, but whether and how BCR signaling is regulated by BCR mobility is still unclear. Here the authors show, using single molecule imaging and machine learning analyses, that BCR and CD19 mobility is modulated by the actin nucleation regulators Arp2/3 and N-WASP to control BCR signaling.
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Affiliation(s)
- Ivan Rey-Suarez
- Biophysics Program, University of Maryland, College Park, MD, 20742, USA.,National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Brittany A Wheatley
- Department of Physics, University of Maryland, College Park, MD, 20742, USA.,Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742, USA
| | - Peter Koo
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Anshuman Bhanja
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, 20742, USA
| | - Zhou Shu
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, 20742, USA.,Division of Immunology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Simon Mochrie
- Department of Physics, Yale University, New Haven, CT, 06520, USA
| | - Wenxia Song
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD, 20742, USA
| | - Hari Shroff
- National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Arpita Upadhyaya
- Biophysics Program, University of Maryland, College Park, MD, 20742, USA. .,Department of Physics, University of Maryland, College Park, MD, 20742, USA. .,Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742, USA.
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