1. An essential role for the Zn2+ transporter ZIP7 in B cell development
- Author
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Tarana Singh Dang, Karin R. Engelhardt, John C. Christianson, Eleanor Cawthorne, M. Teresa de la Morena, David J. Swan, Mirjam van der Burg, Bertrand Boisson, Stuart G. Tangye, Yaobo Xu, J. Ross Chapman, Sarah J. de Jong, Consuelo Anzilotti, T. Ronan Leahy, Pauline Chabosseau, Stefan Przyborski, Mary Ellen Conley, Andreas Werner, B. Christoffer Lagerholm, Adam P. Cribbs, Emma J. Fenech, Cindy S. Ma, David Sims, Mauro Santibanez Koref, Catarina Oliveira, Xijin Xu, Andrew J. Cant, Rui Chen, Luis Alvarez, Sophie Hambleton, Benjamin Davies, Mukta Deobagkar-Lele, Ralph S. Shapiro, Amy Fearn, Jennifer M. Puck, Katherine R. Bull, Jean-Laurent Casanova, Sergi Padilla-Parra, Bert van den Berg, Guy A. Rutter, John A. McGrath, Rolando Berlinguer-Palmini, Tanya L. Crockford, Richard J. Cornall, Gary Kleiner, and Immunology
- Subjects
0301 basic medicine ,Mutation ,Cell signaling ,biology ,Immunology ,B-cell receptor ,Cell ,medicine.disease_cause ,Null allele ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,1107 Immunology ,Cytoplasm ,medicine ,biology.protein ,Immunology and Allergy ,SLC39A7 ,B cell ,030215 immunology - Abstract
Despite the known importance of zinc for human immunity, molecular insights into its roles have remained limited. Here we report a novel autosomal recessive disease characterized by absent B cells, agammaglobulinemia and early onset infections in five unrelated families. The immunodeficiency results from hypomorphic mutations of SLC39A7, which encodes the endoplasmic reticulum-to-cytoplasm zinc transporter ZIP7. Using CRISPR-Cas9 mutagenesis we have precisely modeled ZIP7 deficiency in mice. Homozygosity for a null allele caused embryonic death, but hypomorphic alleles reproduced the block in B cell development seen in patients. B cells from mutant mice exhibited a diminished concentration of cytoplasmic free zinc, increased phosphatase activity and decreased phosphorylation of signaling molecules downstream of the pre-B cell and B cell receptors. Our findings highlight a specific role for cytosolic Zn2+ in modulating B cell receptor signal strength and positive selection.
- Published
- 2019