RT Journal Article
T1 Nonsense CD247 mutations show dominant-negative features in TCR expression and function
A1 Briones Contreras, Alejandro
A1 Megino, Rebeca F.
A1 Marín Marín, Ana Victoria
A1 Chacón Arguedas, Carlos Daniel
A1 García Martínez, Elena
A1 Balastegui Martín, Héctor
A1 Rodríguez Sainz, Carmen
A1 Sánchez-Mateos Rubio, María Paloma
A1 Cárdenas Mastrascusa, Paula Patricia
A1 Regueiro González-Barros, José Ramón
AB BackgroundThe invariant TCRζ/CD247 homodimer is crucial for TCR/CD3 expression and signaling through its three 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.ObjectiveTo analyze and model the potential impact on TCR expression and function of heterozygous nonsense CD247 mutations found in patients with signs of immunodeficiency or autoimmunity.MethodsJurkat T cells, either wild-type (WT) or CRISPR/Cas9-edited CD247-deficient (ZKO), were lentivirally transduced with wild-type CD247 or mutations ablating one (Q142X), two (Q101X), or three (Q70X) ITAMs.ResultsThree 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+3, respectively. Both mutations were associated with low surface CD3 expression, 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 could not restore normal surface CD3 expression (only 60%, 22% and 10%, respectively), whereas in WT they reduced it (to 39%, 19% and 9% of normal levels), and both effects were ITAM number dependent. All six transfectants showed reduced CD69 induction (25-50%), indicating that they were unable to signal downstream properly neither isolated nor associated with wild-type CD247.ConclusionOur results suggest that CD247 variants lacking ITAMs due to nonsense, but not null, mutations are defective for normal TCR assembly and exert a dominant-negative effect on TCR expression and signaling in vitro. This, in turn, may correlate with clinical features in vivo.
PB Elsevier
SN 0091-6749
YR 2024
FD 2024-07-09
LK https://hdl.handle.net/20.500.14352/107379
UL https://hdl.handle.net/20.500.14352/107379
LA eng
NO Briones AC, Megino RF, Marin AV, Chacón-Arguedas D, García-Martinez E, Martín HB, Reyburn HT, Henrickson SE, Rodríguez-Sainz C, Seoane-Reula E, Sanchez-Mateos P, Cardenas PP, Regueiro JR, Nonsense CD247 mutations show dominant-negative features in TCR expression and function, Journal of Allergy and Clinical Immunology (2024), doi: https://doi.org/10.1016/ j.jaci.2024.06.019.
DS Docta Complutense
RD 4 abr 2025