技术资料

The Vps34 (vacuolar protein sorting 34) class III PI3K (phosphoinositide 3-kinase) phosphorylates PtdIns (phosphatidylinositol) at endosomal membranes to generate PtdIns(3)P that regulates membrane trafficking processes via its ability to recruit a subset of proteins possessing PtdIns(3)P-binding PX (phox homology) and FYVE domains. In the present study,we describe a highly selective and potent inhibitor of Vps34,termed VPS34-IN1,that inhibits Vps34 with 25 nM IC50 in vitro,but does not significantly inhibit the activity of 340 protein kinases or 25 lipid kinases tested that include all isoforms of class I as well as class II PI3Ks. Administration of VPS34-IN1 to cells induces a rapid dose-dependent dispersal of a specific PtdIns(3)P-binding probe from endosome membranes,within 1 min,without affecting the ability of class I PI3K to regulate Akt. Moreover,we explored whether SGK3 (serum- and glucocorticoid-regulated kinase-3),the only protein kinase known to interact specifically with PtdIns(3)P via its N-terminal PX domain,might be controlled by Vps34. Mutations disrupting PtdIns(3)P binding ablated SGK3 kinase activity by suppressing phosphorylation of the T-loop [PDK1 (phosphoinositide-dependent kinase 1) site] and hydrophobic motif (mammalian target of rapamycin site) residues. VPS34-IN1 induced a rapid {\~{}}50-60{\%} loss of SGK3 phosphorylation within 1 min. VPS34-IN1 did not inhibit activity of the SGK2 isoform that does not possess a PtdIns(3)P-binding PX domain. Furthermore,class I PI3K inhibitors (GDC-0941 and BKM120) that do not inhibit Vps34 suppressed SGK3 activity by {\~{}}40{\%}. Combining VPS34-IN1 and GDC-0941 reduced SGK3 activity {\~{}}80-90{\%}. These data suggest SGK3 phosphorylation and hence activity is controlled by two pools of PtdIns(3)P. The first is produced through phosphorylation of PtdIns by Vps34 at the endosome. The second is due to the conversion of class I PI3K product,PtdIns(3,4,5)P3 into PtdIns(3)P,via the sequential actions of the PtdIns 5-phosphatases [SHIP1/2 (Src homology 2-domain-containing inositol phosphatase 1/2)] and PtdIns 4-phosphatase [INPP4B (inositol polyphosphate 4-phosphatase type II)]. VPS34-IN1 will be a useful probe to delineate physiological roles of the Vps34. Monitoring SGK3 phosphorylation and activity could be employed as a biomarker of Vps34 activity,in an analogous manner by which Akt is used to probe cellular class I PI3K activity. Combining class I (GDC-0941) and class III (VPS34-IN1) PI3K inhibitors could be used as a strategy to better analyse the roles and regulation of the elusive class II PI3K. View Publication

The stimulator of interferon genes (STING) pathway has been proposed as a key regulator of gastrointestinal homeostasis and inflammatory responses. Although STING reportedly protects against gut barrier damage and graft-versus-host disease (GVHD) after major histocompatibility complex (MHC)-mismatched allogeneic hematopoietic stem cell transplantation (aHSCT),its effect in clinically relevant MHC-matched aHSCT is unknown. Studies here demonstrate that STING signaling in nonhematopoietic cells promoted MHC-matched aHSCT-induced GVHD and that STING agonists increased type I interferon and MHC I expression in nonhematopoietic mouse intestinal organoid cultures. Moreover,mice expressing a human STING allele containing three single-nucleotide polymorphisms associated with decreased STING activity also developed reduced MHC-matched GVHD,demonstrating STING's potential clinical importance. STING-/- recipients experienced reduced GVHD with transplant of purified donor CD8+ T cells in both MHC-matched and MHC-mismatched models,reconciling the seemingly disparate results. Further examination revealed that STING deficiency reduced the activation of donor CD8+ T cells early after transplant and promoted recipient MHC class II+ antigen-presenting cell (APC) survival. Therefore,APC persistence in STING pathway absence may account for the increased GVHD mediated by CD4+ T cells in completely mismatched recipients. In total,our findings have important implications for regulating clinical GVHD by targeting STING early after aHSCT and demonstrate that an innate immune pathway has opposing effects on the outcome of aHSCT,depending on the donor/recipient MHC disparity. View Publication

As SARS-CoV-2 infections and death counts continue to rise,it remains unclear why some individuals recover from infection,whereas others rapidly progress and die. Although the immunological mechanisms that underlie different clinical trajectories remain poorly defined,pathogen-specific antibodies often point to immunological mechanisms of protection. Here,we profiled SARS-CoV-2-specific humoral responses in a cohort of 22 hospitalized individuals. Despite inter-individual heterogeneity,distinct antibody signatures resolved individuals with different outcomes. Although no differences in SARS-CoV-2-specific IgG levels were observed,spike-specific humoral responses were enriched among convalescent individuals,whereas functional antibody responses to the nucleocapsid were elevated in deceased individuals. Furthermore,this enriched immunodominant spike-specific antibody profile in convalescents was confirmed in a larger validation cohort. These results demonstrate that early antigen-specific and qualitative features of SARS-CoV-2-specific antibodies point to differences in disease trajectory,highlighting the potential importance of functional antigen-specific humoral immunity to guide patient care and vaccine development. View Publication

Perhexiline,2-(2,2-dicyclohexylethyl)piperidine,was originally developed as an anti-anginal drug in the 1970s. Despite its success,its use diminished due to the occurrence of poorly understood side effects including neurotoxicity and hepatotoxicity in a small proportion of patients. Recently,perhexiline's mechanism of action and the molecular basis of its toxicity have been elucidated. Perhexiline reduces fatty acid metabolism through the inhibition of carnitine palmitoyltransferase,the enzyme responsible for mitochondrial uptake of long-chain fatty acids. The corresponding shift to greater carbohydrate utilization increases myocardial efficiency (work done per unit oxygen consumption) and this oxygen-sparing effect explains its antianginal efficacy. Perhexiline's side effects are attributable to high plasma concentrations occurring with standard doses in patients with impaired metabolism due to CYP2D6 mutations. Accordingly,dose modification in these poorly metabolizing patients identified through therapeutic plasma monitoring can eliminate any significant side effects. Herein we detail perhexiline's pharmacology with particular emphasis on its mechanism of action and its side effects. We discuss how therapeutic plasma monitoring has led to perhexiline's safe reintroduction into clinical practice and how recent clinical data attesting to its safety and remarkable efficacy led to a renaissance in its use in both refractory angina and chronic heart failure. Finally,we discuss the application of pharmacogenetics in combination with therapeutic plasma monitoring to potentially broaden perhexiline's use in heart failure,aortic stenosis,and other cardiac conditions. View Publication

Although initial treatment of ovarian cancer is successful,tumors typically relapse and become resistant to treatment. Because of poor infiltration of effector T cells,patients are mostly unresponsive to immunotherapy. Plasma gelsolin (pGSN) is transported by exosomes (small extracellular vesicle,sEV) and plays a key role in ovarian cancer chemoresistance,yet little is known about its role in immunosurveillance. Here,we report the immunomodulatory roles of sEV-pGSN in ovarian cancer chemoresistance. In chemosensitive conditions,secretion of sEV-pGSN was low,allowing for optimal CD8+ T-cell function. This resulted in increased T-cell secretion of IFN$\gamma$,which reduced intracellular glutathione (GSH) production and sensitized chemosensitive cells to cis-diaminedichloroplatinum (CDDP)-induced apoptosis. In chemoresistant conditions,increased secretion of sEV-pGSN by ovarian cancer cells induced apoptosis in CD8+ T cells. IFN$\gamma$ secretion was therefore reduced,resulting in high GSH production and resistance to CDDP-induced death in ovarian cancer cells. These findings support our hypothesis that sEV-pGSN attenuates immunosurveillance and regulates GSH biosynthesis,a phenomenon that contributes to chemoresistance in ovarian cancer. SIGNIFICANCE: These findings provide new insight into pGSN-mediated immune cell dysfunction in ovarian cancer chemoresistance and demonstrate how this dysfunction can be exploited to enhance immunotherapy. View Publication

Spontaneous control of human immunodeficiency virus (HIV) is generally associated with an enhanced capacity of CD8+ T cells to eliminate infected CD4+ T cells,but the molecular characteristics of these highly functional CD8+ T cells are largely unknown. In the present study,using single-cell analysis,it was shown that HIV-specific,central memory CD8+ T cells from spontaneous HIV controllers (HICs) and antiretrovirally treated non-controllers have opposing transcriptomic profiles. Genes linked to effector functions and survival are upregulated in cells from HICs. In contrast,genes associated with activation,exhaustion and glycolysis are upregulated in cells from non-controllers. It was shown that HIV-specific CD8+ T cells from non-controllers are largely glucose dependent,whereas those from HICs have more diverse metabolic resources that enhance both their survival potential and their capacity to develop anti-HIV effector functions. The functional efficiency of the HIV-specific CD8+ T cell response in HICs is thus engraved in their memory population and related to their metabolic programme. Metabolic reprogramming in vitro through interleukin-15 treatment abrogated the glucose dependency and enhanced the antiviral potency of HIV-specific CD8+ T cells from non-controllers. View Publication

Several HIV-1 and SIV vaccine candidates have shown partial protection against viral challenges in rhesus macaques. However,the protective efficacy of vaccine-elicited polyclonal antibodies has not previously been demonstrated in adoptive transfer studies in nonhuman primates. In this study,we show that passive transfer of purified antibodies from vaccinated macaques can protect naive animals against SIVmac251 challenges. We vaccinated 30 rhesus macaques with Ad26-SIV Env/Gag/Pol and SIV Env gp140 protein vaccines and assessed the induction of antibody responses and a putative protective signature. This signature included multiple antibody functions and correlated with upregulation of interferon pathways in vaccinated animals. Adoptive transfer of purified immunoglobulin G (IgG) from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naive recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies in this model,even in the absence of virus neutralization. View Publication

A continuing quest for specific inhibitors of proinflammatory cytokines brings promise for effective therapies designed for inflammatory and autoimmune disorders. Cefazolin,a safe,first-generation cephalosporin antibiotic,has been recently shown to specifically interact with interleukin 15 (IL-15) receptor subunit $\alpha$ (IL-15R$\alpha$) and to inhibit IL-15-dependent TNF-$\alpha$ and IL-17 synthesis. The aim of this study was to elucidate cefazolin activity against IL-2,IL-4,IL-15 and IL-21,i.e. four cytokines sharing the common cytokine receptor $\gamma$ chain ($\gamma$c). In silico,molecular docking unveiled two potential cefazolin binding sites within the IL-2/IL-15R$\beta$ subunit and two within the $\gamma$c subunit. In vitro,cefazolin decreased proliferation of PBMC (peripheral blood mononuclear cells) following IL-2,IL-4 and IL-15 stimulation,reduced production of IFN-$\gamma$,IL-17 and TNF-$\alpha$ in IL-2- and IL-15-treated PBMC and in IL-15 stimulated natural killer (NK) cells,attenuated IL-4-dependent expression of CD11c in monocyte-derived dendritic cells and suppressed phosphorylation of JAK3 in response to IL-2 and IL-15 in PBMC,to IL-4 in TF-1 (erythroleukemic cell line) and to IL-21 in NK-92 (NK cell line). The results of the study suggest that cefazolin may exert inhibitory activity against all of the $\gamma$c receptor-dependent cytokines,i.e. IL-2,IL-4,IL-7,IL-9,IL-15 and IL-21. View Publication

We recently demonstrated that the sympathetic nervous system can be voluntarily activated following a training program consisting of cold exposure,breathing exercises,and meditation. This resulted in profound attenuation of the systemic inflammatory response elicited by lipopolysaccharide (LPS) administration. Herein,we assessed whether this training program affects the plasma metabolome and if these changes are linked to the immunomodulatory effects observed. A total of 224 metabolites were identified in plasma obtained from 24 healthy male volunteers at six timepoints,of which 98 were significantly altered following LPS administration. Effects of the training program were most prominent shortly after initiation of the acquired breathing exercises but prior to LPS administration,and point towards increased activation of the Cori cycle. Elevated concentrations of lactate and pyruvate in trained individuals correlated with enhanced levels of anti-inflammatory interleukin (IL)-10. In vitro validation experiments revealed that co-incubation with lactate and pyruvate enhances IL-10 production and attenuates the release of pro-inflammatory IL-1$\beta$ and IL-6 by LPS-stimulated leukocytes. Our results demonstrate that practicing the breathing exercises acquired during the training program results in increased activity of the Cori cycle. Furthermore,this work uncovers an important role of lactate and pyruvate in the anti-inflammatory phenotype observed in trained subjects. View Publication

Antibodies are a principal determinant of immunity for most RNA viruses and have promise to reduce infection or disease during major epidemics. The novel coronavirus SARS-CoV-2 has caused a global pandemic with millions of infections and hundreds of thousands of deaths to date1,2. In response,we used a rapid antibody discovery platform to isolate hundreds of human monoclonal antibodies (mAbs) against the SARS-CoV-2 spike (S) protein. We stratify these mAbs into five major classes on the basis of their reactivity to subdomains of S protein as well as their cross-reactivity to SARS-CoV. Many of these mAbs inhibit infection of authentic SARS-CoV-2 virus,with most neutralizing mAbs recognizing the receptor-binding domain (RBD) of S. This work defines sites of vulnerability on SARS-CoV-2 S and demonstrates the speed and robustness of advanced antibody discovery platforms. View Publication

Cytokine-inducible SH2-containing protein (CIS; encoded by the gene CISH) is a key negative regulator of interleukin-15 (IL-15) signaling in natural killer (NK) cells. Here,we develop human CISH-knockout (CISH-/-) NK cells using an induced pluripotent stem cell-derived NK cell (iPSC-NK cell) platform. CISH-/- iPSC-NK cells demonstrate increased IL-15-mediated JAK-STAT signaling activity. Consequently,CISH-/- iPSC-NK cells exhibit improved expansion and increased cytotoxic activity against multiple tumor cell lines when maintained at low cytokine concentrations. CISH-/- iPSC-NK cells display significantly increased in vivo persistence and inhibition of tumor progression in a leukemia xenograft model. Mechanistically,CISH-/- iPSC-NK cells display improved metabolic fitness characterized by increased basal glycolysis,glycolytic capacity,maximal mitochondrial respiration,ATP-linked respiration,and spare respiration capacity mediated by mammalian target of rapamycin (mTOR) signaling that directly contributes to enhanced NK cell function. Together,these studies demonstrate that CIS plays a key role to regulate human NK cell metabolic activity and thereby modulate anti-tumor activity. View Publication

Endogenous repair of osteochondral defect is usually limited by the insufficient number of cells in the early stage and incomplete cell differentiation in the later stage. The development of drug delivery systems for sequential release of pro-migratory and pro-chondrogenic molecules to induce endogenous bone marrow-derived mesenchymal stem cells (BMSCs) recruitment and chondrogenic differentiation is highly desirable for in situ osteochondral regeneration. In this study,a novel,all-silk-derived sequential delivery system was fabricated by incorporating the tunable drug-loaded silk fibroin (SF) nanospheres into a SF porous matrix. The loading efficiency and release kinetics of biomolecules depended on the initial SF/polyvinyl alcohol (PVA) concentrations (0.2{\%},1{\%} and 5{\%}) of the nanospheres,as well as the hydrophobicity of the loaded molecules,resulting in controllable and programmed delivery profiles. Our findings indicated that the 5{\%} nanosphere-incorporated matrix showed a rapid release of E7 peptide during the first 120 h,whereas the 0.2{\%} nanosphere-incorporated matrix provided a slow and sustained release of Kartogenin (KGN) longer than 30 days. During in vitro culture of BMSCs,this functional SF matrix incorporated with E7/KGN nanospheres showed good biocompatibility,as well as enhanced BMSCs migration and chondrogenic differentiation through the release of E7 and KGN. Furthermore,when implanted into rabbit osteochondral defect,the SF nanosphere matrix with sequential E7/KGN release promoted the regeneration of both cartilage and subchondral bone. This work not only provided a novel all-silk-derived drug delivery system for sequential release of molecules,but also a functional tissue-engineered scaffold for osteochondral regeneration. View Publication