Nonsense CD247 mutations show dominant-negative features in T-cell receptor expression and function

作者：Alejandro C. Briones, Rebeca F. Megino, Ana V. Marín, Daniel Chacón-Arguedas, Elena García-Martínez, Héctor Balastegui-Martín, Hugh T. Reyburn, Sarah E. Henrickson, Carmen Rodríguez-Sáinz, Elena Seoane-Reula, Paloma Sánchez‐Mateos, Paula P. Cárdenas, José R. Regueiro · 发表于：Journal of Allergy and Clinical Immunology · 年份：2024 · DOI：10.1016/j.jaci.2024.06.019 · 被引用次数：11 · 研究领域：CAR-T cell therapy research、Immune Cell Function and Interaction、T-cell and B-cell Immunology

BACKGROUND: The invariant TCR ζ/CD247 homodimer is crucial for TCR/CD3 expression and signaling through its 3 immunoreceptor tyrosine-based activation motifs (ITAMs). Homozygous null mutations in CD247 lead to immunodeficiency, while carriers exhibit 50% reduced surface CD3. It is unclear whether carriers of other CD247 variants show dominant-negative effects. OBJECTIVE: We sought to analyze and model the potential impact on T-cell receptor (TCR) expression and function of heterozygous nonsense CD247 mutations found in patients with signs of immunodeficiency or autoimmunity. METHODS: Jurkat T cells, either wild-type (WT) or CRISPR/Cas9-edited CD247-deficient (ZKO), were lentivirally transduced with WT CD247 or mutations ablating 1 (Q142X), 2 (Q101X), or 3 (Q70X) ITAMs. RESULTS: Three patients from unrelated families were studied. Two heterozygous nonsense CD247 mutations were identified (p.Y152X and p.Q101X), which affected ITAM-3 and ITAM-2 and ITAM-3, respectively. Both mutations were associated with low surface CD3 expression and normal intracellular CD247 levels using a transmembrane-specific antibody, but very low intracellular CD247 levels using an ITAM-3-specific one, suggesting the presence of truncated variants in T cells. Transduction of the mutations lacking 1, 2, or 3 ITAMs into ZKO cells could not restore normal surface CD3 expression (only 60%, 22%, and 10%, respectively), whereas in WT cells, normal surface CD3 expression was reduced (to 39%, 19%, and 9% of nor...