RESUMO
BACKGROUND: Chimeric antigen receptor (CAR) T cells are effective in B-cell malignancies. However, heterogeneous antigen expression and antigen loss remain important limitations of targeted immunotherapy in solid tumors. Therefore, targeting multiple tumor-associated antigens simultaneously is expected to improve the outcome of CAR-T cell therapies. Due to the instability of single-chain variable fragments, it remains challenging to develop the simultaneous targeting of multiple antigens using traditional single-chain fragment variable (scFv)-based CARs. METHODS: We used Humabody VH domains derived from a transgenic mouse to obtain fully human prostate-specific membrane antigen (PSMA) VH and mesothelin (MSLN) VH sequences and redirect T cell with VH based-CAR. The antitumor activity and mode of action of PSMA VH and MSLN VH were evaluated in vitro and in vivo compared with the traditional scFv-based CARs. RESULTS: Human VH domain-based CAR targeting PSMA and MSLN are stable and functional both in vitro and in vivo. VH modules in the bispecific format are capable of binding their specific target with similar affinity as their monovalent counterparts. Bispecific CARs generated by joining two human antibody VH domains can prevent tumor escape in tumor with heterogeneous antigen expression. CONCLUSIONS: Fully human antibody VH domains can be used to generate functional CAR molecules, and redirected T cells elicit antitumoral responses in solid tumors at least as well as conventional scFv-based CARs. In addition, VH domains can be used to generate bispecific CAR-T cells to simultaneously target two different antigens expressed by tumor cells, and therefore, achieve better tumor control in solid tumors.
Assuntos
Antígenos de Superfície/imunologia , Glutamato Carboxipeptidase II/imunologia , Região Variável de Imunoglobulina/imunologia , Imunoterapia Adotiva , Mesotelina/imunologia , Neoplasias da Próstata/terapia , Receptores de Antígenos Quiméricos/imunologia , Anticorpos de Cadeia Única/imunologia , Linfócitos T/transplante , Animais , Linhagem Celular Tumoral , Técnicas de Cocultura , Citocinas/metabolismo , Citotoxicidade Imunológica , Humanos , Região Variável de Imunoglobulina/genética , Ativação Linfocitária , Masculino , Camundongos Endogâmicos NOD , Fenótipo , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/metabolismo , Receptores de Antígenos Quiméricos/genética , Anticorpos de Cadeia Única/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Pancreatic cancer is one of the most lethal forms of cancer and has proven to be difficult to treat through conventional methods, including surgery and chemotherapy. Gene therapy serves as a potential novel treatment to interfere with genes that make this cancer so aggressive, but free nucleic acids have low cell uptake due to their negative charge and are unstable in circulation. Nanoparticles can serve as an effective carrier for a wide variety of gene therapies for pancreatic cancer as they can improve the circulation time, decrease the recognition by the immune system, and be functionalized to target specific surface proteins. In this review, we focus on therapeutic strategies using nanoparticles as carriers of small interfering RNA (siRNA), microRNA (miRNA), and gene augmentation (DNA) therapies in the context of pancreatic cancer. Lastly, we discuss the future outlook of nanoparticle-based therapies, including challenges in the clinical setting.