Lentiviral-mediated gene therapy restores B cell tolerance in Wiskott-Aldrich syndrome patients
Francesca Pala, … , Anna Villa, Eric Meffre
Francesca Pala, … , Anna Villa, Eric Meffre
Published September 14, 2015
Citation Information: J Clin Invest. 2015;125(10):3941-3951. https://doi.org/10.1172/JCI82249.
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Research Article Immunology

Lentiviral-mediated gene therapy restores B cell tolerance in Wiskott-Aldrich syndrome patients

Abstract

Wiskott-Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by microthrombocytopenia, eczema, and high susceptibility to developing tumors and autoimmunity. Recent evidence suggests that B cells may be key players in the pathogenesis of autoimmunity in WAS. Here, we assessed whether WAS protein deficiency (WASp deficiency) affects the establishment of B cell tolerance by testing the reactivity of recombinant antibodies isolated from single B cells from 4 WAS patients before and after gene therapy (GT). We found that pre-GT WASp-deficient B cells were hyperreactive to B cell receptor stimulation (BCR stimulation). This hyperreactivity correlated with decreased frequency of autoreactive new emigrant/transitional B cells exiting the BM, indicating that the BCR signaling threshold plays a major role in the regulation of central B cell tolerance. In contrast, mature naive B cells from WAS patients were enriched in self-reactive clones, revealing that peripheral B cell tolerance checkpoint dysfunction is associated with impaired suppressive function of WAS regulatory T cells. The introduction of functional WASp by GT corrected the alterations of both central and peripheral B cell tolerance checkpoints. We conclude that WASp plays an important role in the establishment and maintenance of B cell tolerance in humans and that restoration of WASp by GT is able to restore B cell tolerance in WAS patients.

Authors

Francesca Pala, Henner Morbach, Maria Carmina Castiello, Jean-Nicolas Schickel, Samantha Scaramuzza, Nicolas Chamberlain, Barbara Cassani, Salome Glauzy, Neil Romberg, Fabio Candotti, Alessandro Aiuti, Marita Bosticardo, Anna Villa, Eric Meffre

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Figure 3

The peripheral B cell tolerance checkpoint is defective in WAS patients.

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The peripheral B cell tolerance checkpoint is defective in WAS patients....
(A) Recombinant antibodies expressed by mature naive (CD19+CD10–CD21+IgM+CD27–) B cells from a representative HD (HD29) and 4 WAS patients were tested by ELISA for reactivity against HEp-2 cell lysate. Dotted lines show ED38+control. Horizontal lines show cutoff OD405 for positive reactivity. The frequencies of HEp-2 reactive and non–HEp-2–reactive clones are summarized in the pie charts, with the number of antibodies tested shown in the center. (B, C, and E) Frequencies of HEp-2–reactive (B), polyreactive (C), and antinuclear (E) mature naive B cells are summarized for HDs and WAS patients (left panels). The evolution of the frequencies of HEp-2–reactive (B), polyreactive (C), and antinuclear (E) B cell clones between the new emigrant and mature naive B cell stages is represented for HDs (open diamonds) and WAS patients (filled diamonds) (right panels). Each symbol represents an individual, and horizontal bars display means. (D) Autoreactive antibodies expressed by WAS mature naive B cells do not recognize nuclear structures and react against cytoplasmic structures. Original magnification, ×40. (B, C, and E) Differences were analyzed for statistical significance using Mann-Whitney test. *P < 0.05 and **P < 0.01.