A congenital neutrophil defect syndrome associated with mutations in VPS45

Thierry Vilboux, Atar Lev, May Christine V. Malicdan, Amos J. Simon, Päivi Järvinen, Tomas Racek, Jacek Puchalka, Raman Sood, Blake Carrington, Kevin Bishop, James Mullikin, Marjan Huizing, Ben Zion Garty, Eran Eyal, Baruch Wolach, Ronit Gavrieli, Amos Toren, Michalle Soudack, Osama M. Atawneh, Tatiana BabushkinGinette Schiby, Andrew Cullinane, Camila Avivi, Sylvie Polak-Charcon, Iris Barshack, Ninette Amariglio, Gideon Rechavi, Jutte Van Der Werff Ten Bosch, Yair Anikster, Christoph Klein, William A. Gahl, Raz Somech

Research output: Contribution to journalArticlepeer-review

105 Scopus citations

Abstract

Background: Neutrophils are the predominant phagocytes that provide protection against bacterial and fungal infections. Genetically determined neutrophil disorders confer a predisposition to severe infections and reveal novel mechanisms that control vesicular trafficking, hematopoiesis, and innate immunity. Methods: We clinically evaluated seven children from five families who had neutropenia, neutrophil dysfunction, bone marrow fibrosis, and nephromegaly. To identify the causative gene, we performed homozygosity mapping using single-nucleotide polymorphism arrays, whole-exome sequencing, immunoblotting, immunofluorescence, electron microscopy, a real-time quantitative polymerase-chain-reaction assay, immunohistochemistry, flow cytometry, fibroblast motility assays, measurements of apoptosis, and zebrafish models. Correction experiments were performed by transfecting mutant fibroblasts with the nonmutated gene. Results: All seven affected children had homozygous mutations (Thr224Asn or Glu238Lys, depending on the child's ethnic origin) in VPS45, which encodes a protein that regulates membrane trafficking through the endosomal system. The level of VPS45 protein was reduced, as were the VPS45 binding partners rabenosyn-5 and syntaxin-16. The level of β1 integrin was reduced on the surface of VPS45-deficient neutrophils and fibroblasts. VPS45-deficient fibroblasts were characterized by impaired motility and increased apoptosis. A zebrafish model of vps45 deficiency showed a marked paucity of myeloperoxidase-positive cells (i.e., neutrophils). Transfection of patient cells with nonmutated VPS45 corrected the migration defect and decreased apoptosis. Conclusions: Defective endosomal intracellular protein trafficking due to biallelic mutations in VPS45 underlies a new immunodeficiency syndrome involving impaired neutrophil function.

Original languageEnglish
Pages (from-to)54-65
Number of pages12
JournalNew England Journal of Medicine
Volume369
Issue number1
DOIs
StatePublished - 2013
Externally publishedYes

Fingerprint

Dive into the research topics of 'A congenital neutrophil defect syndrome associated with mutations in VPS45'. Together they form a unique fingerprint.

Cite this