技术资料

A renewable source of human monocytes and macrophages would be a valuable alternative to primary cells from peripheral blood (PB) in biomedical research. We developed an efficient protocol to derive monocytes and macrophages from human induced pluripotent stem cells (hiPSCs) and performed a functional comparison with PB-derived cells. hiPSC-derived monocytes were functional after cryopreservation and exhibited gene expression profiles comparable with PB-derived monocytes. Notably,hiPSC-derived monocytes were more activated with greater adhesion to endothelial cells under physiological flow. hiPSC-derived monocytes were successfully polarized to M1 and M2 macrophage subtypes,which showed similar pan- and subtype-specific gene and surface protein expression and cytokine secretion to PB-derived macrophages. hiPSC-derived macrophages exhibited higher endocytosis and efferocytosis and similar bacterial and tumor cell phagocytosis to PB-derived macrophages. In summary,we developed a robust protocol to generate hiPSC monocytes and macrophages from independent hiPSC lines that showed aspects of functional maturity comparable with those from PB. View Publication

A proposed strategy to cure HIV uses latency-reversing agents (LRAs) to reactivate latent proviruses for purging HIV reservoirs. A variety of LRAs have been identified,but none has yet proven effective in reducing the reservoir size in vivo. Nanocarriers could address some major challenges by improving drug solubility and safety,providing sustained drug release,and simultaneously delivering multiple drugs to target tissues and cells. Here,we formulated hybrid nanocarriers that incorporate physicochemically diverse LRAs and target lymphatic CD4+ T cells. We identified one LRA combination that displayed synergistic latency reversal and low cytotoxicity in a cell model of HIV and in CD4+ T cells from virologically suppressed patients. Furthermore,our targeted nanocarriers selectively activated CD4+ T cells in nonhuman primate peripheral blood mononuclear cells as well as in murine lymph nodes,and substantially reduced local toxicity. This nanocarrier platform may enable new solutions for delivering anti-HIV agents for an HIV cure. View Publication

Inflammation is a risk factor for cancer development. Individuals with preleukemic TET2 mutations manifest clonal hematopoiesis and are at a higher risk of developing leukemia. How inflammatory signals influence the survival of preleukemic hematopoietic stem and progenitor cells (HSPCs) is unclear. We show a rapid increase in the frequency and absolute number of Tet2-KO mature myeloid cells and HSPCs in response to inflammatory stress,which results in enhanced production of inflammatory cytokines,including interleukin-6 (IL-6),and resistance to apoptosis. IL-6 induces hyperactivation of the Shp2-Stat3 signaling axis,resulting in increased expression of a novel anti-apoptotic long non-coding RNA (lncRNAs),Morrbid,in Tet2-KO myeloid cells and HSPCs. Expression of activated Shp2 in HSPCs phenocopies Tet2 loss with regard to hyperactivation of Stat3 and Morrbid. In vivo,pharmacologic inhibition of Shp2 or Stat3 or genetic loss of Morrbid in Tet2 mutant mice rescues inflammatory-stress-induced abnormalities in HSPCs and mature myeloid cells,including clonal hematopoiesis. View Publication

Niches in the bone marrow regulate hematopoietic stem and progenitor cell (HSPC) fate and behavior through cell-cell interactions and soluble factor secretion. The niche-HSPC crosstalk is a very complex process not completely elucidated yet. To aid further investigation of this crosstalk,a functional in vitro 3D model that closely represents the main supportive compartments of the bone marrow is developed. Different combinations of human stromal cells and hydrogels are tested for their potential to maintain CD34+ HSPCs. Cell viability,clonogenic hematopoietic potential,and surface marker expression are assessed over time. Optimal HSPC support is obtained in presence of adipogenic and osteogenic cells,together with progenitor derived endothelial cells. When cultured in a bioactive hydrogel,the supportive cells self-assemble into a hypoxic stromal network,stimulating CD34+ CD38+ cell formation,while maintaining the pool of CD34+ 38- HSPCs. HSPC clusters colocalize with the stromal networks,in close proximity to sinusoidal clusters of CD31+ endothelial cells. Importantly,the primary in vitro niche model supports HSPCs with no cytokine addition. Overall,the engineered primary 3D bone marrow environment provides an easy and reliable model to further investigate interactions between HSPCs and their endosteal and perivascular niches,in the context of normal hematopoiesis or blood-related diseases. View Publication

Pathobiology of several chronic inflammatory disorders,including ulcerative colitis and Crohn's disease is related to intermittent,spontaneous injury/ulceration of mucosal surfaces. Disease morbidity has been associated with pathologic release of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFalpha). In this report,we show that TNFalpha promotes intestinal mucosal repair through upregulation of the GPCR platelet activating factor receptor (PAFR) in the intestinal epithelium. Platelet activating factor (PAF) was increased in healing mucosal wounds and its engagement with epithelial PAFR leads to activation of epidermal growth factor receptor,Src and Rac1 signaling to promote wound closure. Consistent with these findings,delayed colonic mucosal repair was observed after administration of a neutralizing TNFalpha antibody and in mice lacking PAFR. These findings suggest that in the injured mucosa,the pro-inflammatory milieu containing TNFalpha and PAF sets the stage for reparative events mediated by PAFR signaling. View Publication

Identifying targets present in the tumor microenvironment that contribute to immune evasion has become an important area of research. In this study,we identified EphB4-ephrin-B2 signaling as a regulator of both innate and adaptive components of the immune system. EphB4 belongs to receptor tyrosine kinase family that interacts with ephrin-B2 ligand at sites of cell-cell contact,resulting in bidirectional signaling. We found that EphB4-ephrin-B2 inhibition alone or in combination with radiation (RT) reduced intratumoral regulatory T cells (Tregs) and increased activation of both CD8+ and CD4+Foxp3- T cells compared with the control group in an orthotopic head and neck squamous cell carcinoma (HNSCC) model. We also compared the effect of EphB4-ephrin-B2 inhibition combined with RT with combined anti-PDL1 and RT and observed similar tumor growth suppression,particularly at early time-points. A patient-derived xenograft model showed reduction of tumor-associated M2 macrophages and favored polarization towards an antitumoral M1 phenotype following EphB4-ephrin-B2 inhibition with RT. In vitro,EphB4 signaling inhibition decreased Ki67-expressing Tregs and Treg activation compared with the control group. Overall,our study is the first to implicate the role of EphB4-ephrin-B2 in tumor immune response. Moreover,our findings suggest that EphB4-ephrin-B2 inhibition combined with RT represents a potential alternative for patients with HNSCC and could be particularly beneficial for patients who are ineligible to receive or cannot tolerate anti-PDL1 therapy. SIGNIFICANCE: These findings present EphB4-ephrin-B2 inhibition as an alternative to anti-PDL1 therapeutics that can be used in combination with radiation to induce an effective antitumor immune response in patients with HNSCC. View Publication

Sterol regulatory element binding proteins (SREBPs) are a family of transcription factors that regulate lipid biosynthesis and adipogenesis by controlling the expression of several enzymes required for cholesterol,fatty acid,triacylglycerol and phospholipid synthesis. In vertebrates,SREBP activation is mainly controlled by a complex and well-characterized feedback mechanism mediated by cholesterol,a crucial bio-product of the SREBP-activated mevalonate pathway. In this work,we identified acto-myosin contractility and mechanical forces imposed by the extracellular matrix (ECM) as SREBP1 regulators. SREBP1 control by mechanical cues depends on geranylgeranyl pyrophosphate,another key bio-product of the mevalonate pathway,and impacts on stem cell fate in mouse and on fat storage in Drosophila. Mechanistically,we show that activation of AMP-activated protein kinase (AMPK) by ECM stiffening and geranylgeranylated RhoA-dependent acto-myosin contraction inhibits SREBP1 activation. Our results unveil an unpredicted and evolutionary conserved role of SREBP1 in rewiring cell metabolism in response to mechanical cues. View Publication

The importance of early cancer diagnosis and improved cancer therapy has been clear for years and has initiated worldwide research towards new possibilities in the care strategy of patients with cancer using technological innovations. One of the key research fields involves the separation and detection of circulating tumor cells (CTC) because of their suggested important role in early cancer diagnosis and prognosis,namely,providing easy access by a liquid biopsy from blood to identify metastatic cells before clinically detectable metastasis occurs and to study the molecular and genetic profile of these metastatic cells. Provided the opportunity to further progress the development of technology for treating cancer,several CTC technologies have been proposed in recent years by various research groups and companies. Despite their potential role in cancer healthcare,CTC methods are currently mainly used for research purposes,and only a few methods have been accepted for clinical application because of the difficulties caused by CTC heterogeneity,CTC separation from the blood,and a lack of thorough clinical validation. Therefore,the standardization and clinical application of various developed CTC technologies remain important subsequent necessary steps. Because of their suggested future clinical benefits,we focus on describing technologies using whole blood samples without any pretreatment and discuss their advantages,use,and significance. Technologies using whole blood samples utilize size-based,immunoaffinity-based,and density-based methods or combinations of these methods as well as positive and negative enrichment during separation. Although current CTC technologies have not been truly implemented yet,they possess high potential as future clinical diagnostic techniques for the individualized therapy of patients with cancer. Thus,a detailed discussion of the clinical suitability of these new advanced technologies could help prepare clinicians for the future and can be a foundation for technologies that would be used to eliminate CTCs in vivo. View Publication

Here,we describe the discovery of a naturally occurring human antibody (Ab),FluA-20,that recognizes a new site of vulnerability on the hemagglutinin (HA) head domain and reacts with most influenza A viruses. Structural characterization of FluA-20 with H1 and H3 head domains revealed a novel epitope in the HA trimer interface,suggesting previously unrecognized dynamic features of the trimeric HA protein. The critical HA residues recognized by FluA-20 remain conserved across most subtypes of influenza A viruses,which explains the Ab's extraordinary breadth. The Ab rapidly disrupted the integrity of HA protein trimers,inhibited cell-to-cell spread of virus in culture,and protected mice against challenge with viruses of H1N1,H3N2,H5N1,or H7N9 subtypes when used as prophylaxis or therapy. The FluA-20 Ab has uncovered an exceedingly conserved protective determinant in the influenza HA head domain trimer interface that is an unexpected new target for anti-influenza therapeutics and vaccines. View Publication

To expand the breadth and extent of current multiple myeloma (MM)-specific immunotherapy,we have identified various antigens on CD138+ tumor cells from newly diagnosed MM patients (n = 616) and confirmed B-cell maturation antigen (BCMA) as a key myeloma-associated antigen. The aim of this study is to target the BCMA,which promotes MM cell growth and survival,by generating BCMA-specific memory CD8+ CTL that mediate effective and long-lasting immunity against MM. Here we report the identification of novel engineered peptides specific to BCMA,BCMA72-80 (YLMFLLRKI),and BCMA54-62 (YILWTCLGL),which display improved affinity/stability to HLA-A2 compared to their native peptides and induce highly functional BCMA-specific CTL with increased activation (CD38,CD69) and co-stimulatory (CD40L,OX40,GITR) molecule expression. Importantly,the heteroclitic BCMA72-80 specific CTL demonstrated poly-functional Th1-specific immune activities [IFN-gamma/IL-2/TNF-alpha production,proliferation,cytotoxicity] against MM,which were correlated with expansion of Tetramer+ and memory CD8+ CTL. Additionally,heteroclitic BCMA72-80 specific CTL treated with anti-OX40 (immune agonist) or anti-LAG-3 (checkpoint inhibitor) display increased immune function,mainly by central memory CTL. These results provide the framework for clinical application of heteroclitic BCMA72-80 peptide,alone and in combination with anti-LAG3 and/or anti-OX40 therapy,in vaccination and/or adoptive immunotherapeutic strategies to generate long-lasting anti-tumor immunity in patients with MM or other BCMA expressing tumors. View Publication

Lupus nephritis is a potentially fatal autoimmune disease for which the current treatment is ineffective and often toxic. To develop mechanistic hypotheses of disease,we analyzed kidney samples from patients with lupus nephritis and from healthy control subjects using single-cell RNA sequencing. Our analysis revealed 21 subsets of leukocytes active in disease,including multiple populations of myeloid cells,T cells,natural killer cells and B cells that demonstrated both pro-inflammatory responses and inflammation-resolving responses. We found evidence of local activation of B cells correlated with an age-associated B-cell signature and evidence of progressive stages of monocyte differentiation within the kidney. A clear interferon response was observed in most cells. Two chemokine receptors,CXCR4 and CX3CR1,were broadly expressed,implying a potentially central role in cell trafficking. Gene expression of immune cells in urine and kidney was highly correlated,which would suggest that urine might serve as a surrogate for kidney biopsies. View Publication

Rheumatoid arthritis is characterized by progressive joint inflammation and affects {\~{}}1{\%} of the human population. We noted single-nucleotide polymorphisms (SNPs) in the apoptotic cell-engulfment genes ELMO1,DOCK2,and RAC1 linked to rheumatoid arthritis. As ELMO1 promotes cytoskeletal reorganization during engulfment,we hypothesized that ELMO1 loss would worsen inflammatory arthritis. Surprisingly,Elmo1-deficient mice showed reduced joint inflammation in acute and chronic arthritis models. Genetic and cell-biology studies revealed that ELMO1 associates with receptors linked to neutrophil function in arthritis and regulates activation and early neutrophil recruitment to the joints,without general inhibition of inflammatory responses. Further,neutrophils from the peripheral blood of human donors that carry the SNP in ELMO1 associated with arthritis display increased migratory capacity,whereas ELMO1 knockdown reduces human neutrophil migration to chemokines linked to arthritis. These data identify 'noncanonical' roles for ELMO1 as an important cytoplasmic regulator of specific neutrophil receptors and promoter of arthritis. View Publication