Objective To establish the high-throughput screening fluorescence polarization assay for HSP90 inhibitor.Methods E.coli strain BL21 ( DE3) competent cells were transformed with pET24α( +)-HSP90αplasmid.The cell lysate supernatant was induced to product the soluble protein and purified with Ni-NTA agarose.Western blot analysis was used to identify whether the purified protein is HSP90α.The fluorescence polarization assay for screening HSP90 inhibitors was established and optimized using varying concentrations of recombinant HSP90 protein and molecular probe VER00051001.Meanwhile, the binding activity of GA and NVP-AUY922 for HSP90αwas measured by fluorescence polarization assay.Results HSP90αwas induced expression and purified successfully.The fluorescence polarization assay was performed using 80 nM probe VER00051001 and 2.01μg/mL HSP90α, with the Z factor of 0.83.GA and NVP-AUY922 competed with the probes VER00051001 for binding sites of HSP90, with IC50 of 55 nM and 13 nM, respectively.Conclusion A reliable model was established using fluorescence polarization assay for screening HSP90 inhibitors.

Objective To investigate the effect of different stimulants on the LAG3 expression and function of spleen lymphocytes in mice. Methods The spleen lymphocytes from mice were isolated by density centrifugation.The LAG3 expressions in T cell subsets after exposure to conA, PMA, PHA or anti-CD3/28 antibodies for 24 h or 72 h were analyzed by Flow cytometry.The IFN-γsecretions of conditional medium were detected by ELISA kit.The proliferation of lymphocytes was examined by MTT analysis.Results Treatment with conA for 24 h or 72 h dose-dependently increased LAG3 +CD3 +and LAG3 +CD4 +CD3 +T cell percentages.Similarly, an exposure of anti-CD3/28 antibodies for 72 h significantly increased LAG3 +CD3 +and LAG3 +CD4 +CD3 + T cell percentages.Meanwhile, conA and anti-CD3/28 antibodies increased the IFN-γsecretion of lymphocytes in a time-dependent manner.Furthermore, Treatment with conA, PMA, PHA or anti-CD3/28 antibodies for 72 h could enhance the proliferation of lymphocyte. Conclusion conA and anti-CD3/28 antibodies are effective activators of T cells, and both of them could promote the expression of LAG3 and IFN-γsecretion of lymphocytes.

PD-1 and PD-L1 antibodies have brought about extraordinary clinical benefits for cancer patients, and their indications are expanding incessantly. Currently, most PD-1/PD-L1 agents are administered intravenously, which may be uncomfortable for some cancer patients. Herein, we develop a novel oral-delivered small molecular, YPD-29B, which specifically targets human PD-L1. Our data suggested that YPD-29B could potently and selectively block the interaction between PD-L1 and PD-1, but did not inhibit any other immune checkpoints. Mechanistically, YPD-29B induced human PD-L1 dimerization and internalization, which subsequently activated T lymphocytes and therefore overcomes immunity tolerance in vitro. YDP-29B was modified as the YPD-30 prodrug to improve druggability. Using humanized mice with human PD-1 xenografts of human PD-L1 knock-in mouse MC38 cancer cells, we demonstrated that YPD-30 exhibited significant antitumor activity and was well tolerated in vivo. Taken together, our results indicate that YPD-30 serves as a promising therapeutic candidate for anti-human PD-L1 cancer immunotherapy.

[This corrects the article DOI: 10.1016/j.apsb.2022.02.031.].

Glioblastoma (GBM) is a highly aggressive and lethal brain tumor with an immunosuppressive tumor microenvironment (TME). In this environment, myeloid cells, such as myeloid-derived suppressor cells (MDSCs), play a pivotal role in suppressing antitumor immunity. Lipometabolism is closely related to the function of myeloid cells. Here, our study reports that acetyl-CoA acetyltransferase 1 (ACAT1), the key enzyme of fatty acid oxidation (FAO) and ketogenesis, is significantly downregulated in the MDSCs infiltrated in GBM patients. To investigate the effects of ACAT1 on myeloid cells, we generated mice with myeloid-specific (LyzM-cre) depletion of ACAT1. The results show that these mice exhibited a remarkable accumulation of MDSCs and increased tumor progression both ectopically and orthotopically. The mechanism behind this effect is elevated secretion of C-X-C motif ligand 1 (CXCL1) of macrophages (Mφ). Overall, our findings demonstrate that ACAT1 could serve as a promising drug target for GBM by regulating the function of MDSCs in the TME.

Psoriasis is characterized by abnormal proliferation of keratinocytes, as well as infiltration of immune cells into the dermis and epidermis, causing itchy, scaly and erythematous plaques of skin. The understanding of this chronic inflammatory skin disease remains unclear and all available treatments have their limitations currently. Here, we showed that IMMH002, a novel orally active S1P modulator, desensitized peripheral pathogenic lymphocytes to egress signal from secondary lymphoid organs and thymus. Using different psoriasis animal models, we demonstrated that IMMH002 could significantly relieve skin damage as revealed by PASI score and pathological injure evaluation. Mechanistically, IMMH002 regulated CD3 T lymphocytes re-distribution by inducing lymphocytes' homing, thus decreased T lymphocytes allocation in the peripheral blood and skin but increased in the thymus. Our results suggest that the novel S1P agonist, IMMH002, exert extraordinary capacity to rapidly modulate T lymphocytes distribution, representing a promising drug candidate for psoriasis treatment.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with unclear etiology and limited treatment options. The median survival time for IPF patients is approximately 2-3 years and there is no effective intervention to treat IPF other than lung transplantation. As important components of lung tissue, endothelial cells (ECs) are associated with pulmonary diseases. However, the role of endothelial dysfunction in pulmonary fibrosis (PF) is incompletely understood. Sphingosine-1-phosphate receptor 1 (S1PR1) is a G protein-coupled receptor highly expressed in lung ECs. Its expression is markedly reduced in patients with IPF. Herein, we generated an endothelial-conditional S1pr1 knockout mouse model which exhibited inflammation and fibrosis with or without bleomycin (BLM) challenge. Selective activation of S1PR1 with an S1PR1 agonist, IMMH002, exerted a potent therapeutic effect in mice with bleomycin-induced fibrosis by protecting the integrity of the endothelial barrier. These results suggest that S1PR1 might be a promising drug target for IPF therapy.