A peptide derived from the Wiskott-Aldrich syndrome (WAS) protein-interacting protein (WIP) restores WAS protein level and actin cytoskeleton reorganization in lymphocytes from patients with WAS mutations that disrupt WIP binding.

Abstract

BACKGROUND:

The Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are caused by mutations in WAS, which encodes for WAS protein (WASP). The WASP-interacting protein (WIP) stabilizes WASP, as evidenced by severely decreased WASP levels in T cells from WIP-deficient mice. The majority of missense mutations in patients with WAS/XLT are located in the WIP-binding domain of WASP and might result in dissociation of the WASP-WIP complex and WASP degradation.

OBJECTIVE:

To restore WASP levels and correct T-cell function in WAS/XLT patients with mutations in the WIP-binding domain of WASP.

METHODS:

WIP, and a WIP-derived 41-amino acid-long peptide, which interacts with WASP and was designated nanoWIP (nWIP), were fused to enhanced green fluorescent protein and introduced by electroporation into EBV-transformed B cells, and by retroviral transduction into purified blood T cells from patients with WAS. WASP levels were measured by intracellular fluorescence-activated cell sorting staining. The actin cytoskeleton was visualized by intracellular phalloidin staining.

RESULTS:

Introduction of WIP and nWIP restored WASP levels to normal in EBV-transformed B-cell lines from XLT patients with missense mutations in the WIP-binding domain of WASP and residual WASP levels, and corrected the defective spreading and pseudopodia formation of their T cells in response to immobilized anti-CD3.

CONCLUSION:

A WASP-binding WIP-derived peptide stabilizes WASP in cells from XLT patients with missense mutations that disrupt WIP binding, and corrects their T-cell actin cytoskeleton defect. This may provide a novel therapeutic strategy for these patients.

• Authors: Michel J Massaad, Narayanaswamy Ramesh, Severine Le Bras, Silvia Giliani, Lucia D Notarangelo, Waleed Al-Herz, Luigi D Notarangelo, Raif S Geha
• Journal: The Journal of allergy and clinical immunology (J Allergy Clin Immunol) Vol. 127 Issue 4 Pg. 998-1005.e1-2 (Apr 2011) ISSN: 1097-6825 [Electronic] United States
• PMID: 21376381 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Chemical References

• Actins
• Cytoskeletal Proteins
• Intracellular Signaling Peptides and Proteins
• Peptides
• WIPF1 protein, human
• Wiskott-Aldrich Syndrome Protein

Topics

• Actins (metabolism)
• Animals
• B-Lymphocytes (metabolism)
• Blotting, Western
• Cell Separation
• Cytoskeletal Proteins (metabolism)
• Cytoskeleton (metabolism, pathology)
• Electroporation
• Flow Cytometry
• Humans
• Immunoprecipitation
• Intracellular Signaling Peptides and Proteins (metabolism)
• Jurkat Cells
• Mice
• Mice, Knockout
• Microscopy, Fluorescence
• Mutation, Missense
• Peptides
• Reverse Transcriptase Polymerase Chain Reaction
• T-Lymphocytes (metabolism, pathology)
• Transduction, Genetic
• Wiskott-Aldrich Syndrome (genetics, metabolism)
• Wiskott-Aldrich Syndrome Protein (genetics, metabolism)