Rescuing the cytolytic function of APDS1 patient T cells via TALEN-mediated PIK3CD gene correction
Lucie Poggi1,2, Loïc Chentout1,2, Sabrina Lizot3
1Université de Paris Cité, Imagine Institute, Paris, France.
Abstract:
Gain-of-function mutations in the PIK3CD gene result in activated phosphoinositide 3-kinase δ syndrome type 1 (APDS1). This syndrome is a life-threatening combined immunodeficiency and today there are neither optimal nor long-term therapeutic solutions for APDS1 patients. Thus, new alternative treatments are highly needed. The aim of the present study is to explore one therapeutic avenue that consists of the correction of the PIK3CD gene through gene editing. Our proof-of-concept shows that TALEN-mediated gene correction of the mutated PIK3CD gene in APDS1 T cells results in normalized phospho-AKT levels in basal and activated conditions. Normalization of PI3K signaling was correlated to restored cytotoxic functions of edited CD8+ T cells. At the transcriptomic level, single-cell RNA sequencing revealed corrected signatures of CD8+ effector memory and CD8+ proliferating T cells. This proof-of-concept study paves the way for the future development of a gene therapy candidate to cure activated phosphoinositide 3-kinase δ syndrome type 1.
Insights
Gene editing offers a promising new treatment for activated phosphoinositide 3-kinase δ syndrome type 1 (APDS1). Correcting the PIK3CD gene in APDS1 T cells restored normal signaling and immune cell function, paving the way for gene therapy.
Area of Science:
- Immunology
- Genetics
- Molecular Biology
Background:
- Activated phosphoinositide 3-kinase δ syndrome type 1 (APDS1) is a severe combined immunodeficiency caused by gain-of-function mutations in the PIK3CD gene.
- Current therapeutic options for APDS1 are limited, highlighting the urgent need for novel treatment strategies.
Purpose of the Study:
- To investigate the potential of gene editing as a therapeutic approach for APDS1 by correcting the mutated PIK3CD gene.
- To assess the functional restoration of immune cells following gene correction in APDS1 patients.
Main Methods:
- Utilized TALEN-mediated gene editing to correct the PIK3CD mutation in T cells from APDS1 patients.
- Assessed PI3K/AKT signaling pathway activity through phospho-AKT levels.
- Evaluated cytotoxic functions of CD8+ T cells.
- Performed single-cell RNA sequencing to analyze transcriptomic changes in edited T cells.
Main Results:
- TALEN-mediated gene correction normalized phospho-AKT levels in APDS1 T cells under both basal and stimulated conditions.
- Correction of PI3K signaling correlated with the restoration of CD8+ T cell cytotoxic functions.
- Single-cell RNA sequencing demonstrated corrected transcriptomic signatures associated with CD8+ effector memory and proliferating T cells.
Conclusions:
- Gene editing of the PIK3CD gene is a viable proof-of-concept for treating APDS1.
- This approach shows potential for restoring immune cell function and offers a promising avenue for developing a gene therapy for APDS1.
