Search

Hematopoietic progenitor kinase 1 (HPK1, MAP4K1), a serine/threonine (SER/THR) kinase, has been identified as a negative immune regulator of T-cell receptor signaling. Deprivation of the HPK1 function suppresses tumor growth, providing an attractive strategy for cancer immunotherapy. Herein, we present a novel PROTAC-based HPK1 degrader compound DD205-291 with high selectivity and potency. DD205-291 showed a dose-dependent inhibition of SLP-76 phosphorylation and an induction of IL-2 and IFN-γ. Compared with other inhibitors, DD205-291 exhibited good efficacy and a favorable safety profile in the MC38 model. Specifically, oral administration of DD205-291 at 0.5 mg/kg in combination with anti-PD1 resulted in significant suppression with a TGI value of 91.0%. Furthermore, DD205-291 exhibited a low risk of cardiotoxicity and a wide safety window. This research effort demonstrates that DD205-291 is a promising preclinical candidate (PCC) for potential mono- and comboimmunotherapy of cancer.

Ankylosing spondylitis (AS) is a chronic immune-mediated disease. Various immune cells play an essential role in the AS pathogenesis. However, the specific pathogenesis of AS has not been well understood. Proteomic profiles of peripheral blood mononuclear cells (PBMCs) were applied to reveal the specific pathogenesis of AS. Quantitative proteomic analyses were performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based methods to investigate the protein profiling of PBMCs from new-onset AS patients ( n = 9) and healthy controls ( n = 9). We identified 782 differentially expressed proteins (DEPs) and 527 differentially phosphorylated proteins (DPPs) between AS patients and healthy controls. The subcellular location of DEPs and DPPs showed that most of the DEPs were from the cytoplasm ( n = 296, 38%), were extracellular ( n = 141, 18%), and from the nucleus ( n = 114, 15%); most of the DPPs were from the cytoplasm ( n = 37, 34%), nucleus ( n = 35, 32%), and plasma membrane ( n = 10, 9%). We further identified 89 proteins with both expression and phosphorylation differences. The functional annotation of the 89 differentially expressed and phosphorylated proteins enriched in the antigen processing and presentation pathway. Four DEPs with six phosphorylated positions were found in the antigen processing and presentation pathway. The differentially expressed and phosphorylated proteins may be helpful to uncover the pathogenesis of AS. The six AS-specific proteins may serve as candidate markers for AS diagnosis and new treatment targets., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

All-inorganic colloidal perovskite quantum dots (QDs) based on cesium, lead, and halide have recently emerged as promising light emitting materials. CsPbBr 3 QDs have also been demonstrated as stable two-photon-pumped lasing medium. However, the reported two photon absorption (TPA) cross sections for these QDs differ by an order of magnitude. Here we present an in-depth study of the TPA properties of CsPbBr 3 QDs with mean size ranging from 4.6 to 11.4 nm. By using femtosecond transient absorption (TA) spectroscopy we found that TPA cross section is proportional to the linear one photon absorption. The TPA cross section follows a power law dependence on QDs size with exponent 3.3 ± 0.2. The empirically obtained power-law dependence suggests that the TPA process through a virtual state populates exciton band states. The revealed power-law dependence and the understanding of TPA process are important for developing high performance nonlinear optical devices based on CsPbBr 3 nanocrystals.

Paracellular permeability enhancers have been used to improve the oral bioavailability of hydrophilic drugs; however, the mechanism of action of many enhancers is poorly understood. In this study, highly potent enhancers of paracellular permeability were identified in the 3-alkylamido-2-alkoxypropylphosphocholine series, and a structure-activity relationship was developed for enhancement of paracellular permeability across Caco-2 cell monolayers. Compounds with short (<5 carbons) hydrocarbon chains at both C-2 and C-3 were generally inactive. The potency exhibited a parabolic relationship with respect to the chain length at either C-2 or C-3. Linear molecules (i.e., compounds with a short hydrocarbon chain at C-2 or C-3 and a long hydrocarbon chain on C-3 or C-2, respectively) were more potent than the corresponding branched molecules with the same carbon load. The efficacy of 3-alkylamido-2-alkoxypropylphosphocholines as enhancers of paracellular permeability was not dependent on their existence in micellar form or their ability to alter the fluidity of cell membrane. Previously, a correlation between the potency of alkylphosphocholines as enhancers of paracellular permeability and the inhibitors of phospholipase C (PLC) was established in Madine Darby canine kidney (MDCK) cell monolayers. The potencies of selected 3-alkylamido-2-alkoxypropylphosphocholines as inhibitors of PLC and enhancers of paracellular permeability fit well into this correlation. Therefore, phosphocholines are likely to increase paracellular permeability by modulating the signal transduction pathway initiated by a PLC-catalyzed reaction rather than by physically altering the cell membrane.