Structural basis for the inhibition of the papain-like protease of SARS-CoV-2 by small molecules

SARS-CoV-2 is the pathogen responsible for the COVID-19 pandemic. The SARS-CoV-2 papain-like cysteine protease has been implicated in virus maturation, dysregulation of host inflammation and antiviral immune responses. We showed that PLpro preferably cleaves the K48-ubiquitin linkage while also being capable of cleaving ISG15 modification. The multiple functions of PLpro render it a promising drug target. Therefore, we screened an FDA-approved drug library and also examined available inhibitors against PLpro. Inhibitor GRL0617 showed a promising IC50 of 2.1 M. The co-crystal structure of SARS-CoV-2 PLpro-C111S in complex with GRL0617 suggests that GRL0617 is a non-covalent inhibitor. NMR data indicate that GRL0617 blocks the binding of ISG15 to PLpro. The antiviral activity of GRL0617 reveal that PLpro is a promising drug target for therapeutically treating COVID-19. One Sentence SummaryCo-crystal structure of PLpro in complex with GRL0617 reveals the druggability of PLpro for SARS-CoV-2 treatment.

Phase Ⅱ clinical trail of patients with relapsed follicular lymphoma treated with a humanized anti-programmed death-1 monoclonal antibody combined with rituximab:report in the 54th ASH annual meeting / 白血病·淋巴瘤

Objective A phase Ⅱ trial of anti-programmed death-1 (PD-1) monoclonal antibody CT-011,an anti PD-1 humanized monoclonal antibody combined with rituximab therapy in patients with relapsed follicular lymphoma (FL) were conducted.Methods In order to evaluate the safety and efficacy of CT-011,the impacts of CT-011 on immune cells both from the peripheral blood (PB) samples and tumor microenvironment were examined.PB and core needle biopsies from involved lymph nodes were collected prior to and on day 14 after the first infusion of CT-011.PB mononuclear cells (PBMC) were analyzed by multiparametric flow cytometry to determine various immune cell subsets.Whole genome gene expression profiling (GEP) was performed on core needle biopsies.Results A significant increase in the absolute number of PB immune cells were observed in day 14 samples compared with baseline including total lymphocyte count (P ＜ 0.01),CD+3 T cells (P =0.01),CD+4 T cells (P ＜ 0.01).Comparison of GEP from core needle biopsies obtained pretreatment and day 14 (n =8 pairs) showed up regulation of several genes associated with T cell activation.Conclusion Administration of CT-011 was associated with increase in the numbers of CD+4 T cells and resulted in activation of T cells in the PB and the tumor microenvironment in FL.These results provide insight into the mechanism of action of CT-011 and offer a predictive biomarker for selection of patients for future clinical trials with this class of agents in FL.