RESUMO
Protein tyrosine phosphatase nonreceptor Type 2 (PTPN2) is an attractive target for cancer immunotherapy. PTPN2 and another subtype of PTP1B are highly similar in structure, but their biological functions are distinct. Therefore, subtype-selective targeting of PTPN2 remains a challenge for researchers. Herein, the development of small molecular PTPN2 degraders based on a thiadiazolidinone dioxide-naphthalene scaffold and a VHL E3 ligase ligand is described, and the PTPN2/PTP1B subtype-selective degradation is achieved for the first time. The linker structure modifications led to the discovery of the subtype-selective PTPN2 degrader PVD-06 (PTPN2/PTP1B selective index > 60-fold), which also exhibits excellent proteome-wide degradation selectivity. PVD-06 induces PTPN2 degradation in a ubiquitination- and proteasome-dependent manner. It efficiently promotes T cell activation and amplifies IFN-γ-mediated B16F10 cell growth inhibition. This study provides a convenient chemical knockdown tool for PTPN2-related research and a paradigm for subtype-selective PTP degradation through nonspecific substrate-mimicking ligands, demonstrating the therapeutic potential of PTPN2 subtype-selective degradation.
Assuntos
Proteína Tirosina Fosfatase não Receptora Tipo 2 , Ubiquitina-Proteína Ligases , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Fosforilação , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Complexo de Endopeptidases do Proteassoma/metabolismoRESUMO
C57BL/6 mice were inoculated intranasally (50 microl) with serial 10-fold dilution of HAB/01 H5N1 virus. Three and five days later, three mice of each group were euthanized. Lung injury was assessed by observation of lung histopathology, virus titers and MCD50 were also measured. Our data showed that H5N1 viral infection in mice resulted in mainly epithelial injury and interstitial pneumonia, featuring significant weight loss, dramatically increased lung wet weight:body weight ratio, inflammatory cellular infiltration, alveolar and interstitial edema, hemorrhage in lungs with high virus titers, and MCD50 was 10(-6.5)/ 0.05 mL. These results suggested that a mouse model of H5N1 viral infection was successfully established which may benefit study of H5N1 avian influenza virus and pathogenic mechanism of host.