RESUMO
The treatment of patients with acute myeloid leukemia (AML) with targeted immunotherapy is challenged by the heterogeneity of the disease and a lack of tumor-exclusive antigens. Conventional immunotherapy targets for AML such as CD33 and CD123 have been proposed as targets for chimeric antigen receptor (CAR)-engineered T-cells (CAR-T-cells), a therapy that has been highly successful in the treatment of B-cell leukemia and lymphoma. However, CD33 and CD123 are present on hematopoietic stem cells, and targeting with CAR-T-cells has the potential to elicit long-term myelosuppression. C-type lectin-like molecule-1 (CLL1 or CLEC12A) is a myeloid lineage antigen that is expressed by malignant cells in more than 90% of AML patients. CLL1 is not expressed by healthy Hematopoietic Stem Cells (HSCs), and is therefore a promising target for CAR-T-cell therapy. Here, we describe the development and optimization of an anti-CLL1 CAR-T-cell with potent activity on both AML cell lines and primary patient-derived AML blasts in vitro while sparing healthy HSCs. Furthermore, in a disseminated mouse xenograft model using the CLL1-positive HL60 cell line, these CAR-T-cells completely eradicated tumor, thus supporting CLL1 as a promising target for CAR-T-cells to treat AML while limiting myelosuppressive toxicity.
Assuntos
Lectinas Tipo C/antagonistas & inibidores , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores Mitogênicos/antagonistas & inibidores , Proteínas Recombinantes de Fusão , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Modelos Animais de Doenças , Feminino , Humanos , Imunoterapia Adotiva/métodos , Lectinas Tipo C/imunologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores Mitogênicos/imunologia , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Antidiabetic treatments aiming to reduce body weight are currently gaining increased interest. Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist administered twice daily via s.c. injection, improves glycemic control, often with associated weight reduction. To further improve the therapeutic efficacy of exendin-4, we have developed a novel peptide engineering strategy that incorporates a serum protein binding motif onto a covalent side-chain staple and applied to the peptide to enhance its helicity and, as a consequence, its potency and serum half-life. We demonstrated that one of the resulting peptides, E6, has significantly improved half-life and glucose tolerance in an oral glucose tolerance test in rodents. Chronic treatment of E6 significantly decreased body weight and fasting blood glucose, improved lipid metabolism, and also reduced hepatic steatosis in diet-induced obese mice. Moreover, the high potency of E6 allowed us to administer this peptide using a dissolvable microstructure-based transdermal delivery system. Pharmacokinetic and pharmacodynamic studies in guinea pigs showed that a single 5-min application of a microstructure system containing E6 significantly improved glucose tolerance for 96 h. This delivery strategy may offer an effective and patient-friendly alternative to currently marketed GLP-1 injectables and can likely be extended to other peptide hormones.
