An essential role for the Zn 2+ transporter ZIP7 in B cell development

Nat Immunol. 2019 Mar;20(3):350-361. doi: 10.1038/s41590-018-0295-8. Epub 2019 Feb 4.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agammaglobulinemia / genetics
  • Agammaglobulinemia / immunology*
  • Agammaglobulinemia / metabolism
  • Animals
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • Cation Transport Proteins / deficiency
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / immunology*
  • Child, Preschool
  • Cytosol / immunology
  • Cytosol / metabolism
  • Disease Models, Animal
  • Endoplasmic Reticulum / immunology
  • Endoplasmic Reticulum / metabolism
  • Female
  • Gene Expression Profiling
  • Humans
  • Infant
  • Male
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mutation
  • Pedigree
  • Zinc / immunology*
  • Zinc / metabolism

Substances

  • Cation Transport Proteins
  • SLC39A7 protein, human
  • Zinc