An anti-sortilin affibody-peptide fusion inhibits sortilin-mediated progranulin degradation.
Front Immunol
; 15: 1437886, 2024.
Article
em En
| MEDLINE
| ID: mdl-39185427
ABSTRACT
Heterozygous loss-of-function mutations in the GRN gene are a common cause of frontotemporal dementia. Such mutations lead to decreased plasma and cerebrospinal fluid levels of progranulin (PGRN), a neurotrophic factor with lysosomal functions. Sortilin is a negative regulator of extracellular PGRN levels and has shown promise as a therapeutic target for frontotemporal dementia, enabling increased extracellular PGRN levels through inhibition of sortilin-mediated PGRN degradation. Here we report the development of a high-affinity sortilin-binding affibody-peptide fusion construct capable of increasing extracellular PGRN levels in vitro. By genetic fusion of a sortilin-binding affibody generated through phage display and a peptide derived from the progranulin C-terminus, an affinity protein (A3-PGRNC15*) with 185-pM affinity for sortilin was obtained. Treating PGRN-secreting and sortilin-expressing human glioblastoma U-251 cells with the fusion protein increased extracellular PGRN levels up to 2.5-fold, with an EC50 value of 1.3 nM. Our results introduce A3-PGRNC15* as a promising new agent with therapeutic potential for the treatment of frontotemporal dementia. Furthermore, the work highlights means to increase binding affinity through synergistic contribution from two orthogonal polypeptide units.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Recombinantes de Fusão
/
Proteínas Adaptadoras de Transporte Vesicular
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Proteólise
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Progranulinas
Limite:
Humans
Idioma:
En
Revista:
Front Immunol
Ano de publicação:
2024
Tipo de documento:
Article