技术资料

MicroRNAs play an important role in T cell responses. However,how microRNAs regulate CD8 T cell memory remains poorly defined. Here,we found that miR-150 negatively regulates CD8 T cell memory in vivo. Genetic deletion of miR-150 disrupted the balance between memory precursor and terminal effector CD8 T cells following acute viral infection. Moreover,miR-150-deficient memory CD8 T cells were more protective upon rechallenge. A key circuit whereby miR-150 repressed memory CD8 T cell development through the transcription factor c-Myb was identified. Without miR-150,c-Myb was upregulated and anti-apoptotic targets of c-Myb,such as Bcl-2 and Bcl-xL,were also increased,suggesting a miR-150-c-Myb survival circuit during memory CD8 T cell development. Indeed,overexpression of non-repressible c-Myb rescued the memory CD8 T cell defects caused by overexpression of miR-150. Overall,these results identify a key role for miR-150 in memory CD8 T cells through a c-Myb-controlled enhanced survival circuit. View Publication

Tumor-associated macrophages (TAMs) originate as circulating monocytes,and are recruited to gliomas,where they facilitate tumor growth and migration. Understanding the interaction between TAM and cancer cells may identify therapeutic targets for glioblastoma multiforme (GBM). Vascular cell adhesion molecule-1 (VCAM-1) is a cytokine-induced adhesion molecule expressed on the surface of cancer cells,which is involved in interactions with immune cells. Analysis of the glioma patient database and tissue immunohistochemistry showed that VCAM-1 expression correlated with the clinico-pathological grade of gliomas. Here,we found that VCAM-1 expression correlated positively with monocyte adhesion to GBM,and knockdown of VCAM-1 abolished the enhancement of monocyte adhesion. Importantly,upregulation of VCAM-1 is dependent on epidermal-growth-factor-receptor (EGFR) expression,and inhibition of EGFR effectively reduced VCAM-1 expression and monocyte adhesion activity. Moreover,GBM possessing higher EGFR levels (U251 cells) had higher VCAM-1 levels compared to GBMs with lower levels of EGFR (GL261 cells). Using two- and three-dimensional cultures,we found that monocyte adhesion to GBM occurs via integrin α4β1,which promotes tumor growth and invasion activity. Increased proliferation and tumor necrosis factor-α and IFN-γ levels were also observed in the adherent monocytes. Using a genetic modification approach,we demonstrated that VCAM-1 expression and monocyte adhesion were regulated by the miR-181 family,and lower levels of miR-181b correlated with high-grade glioma patients. Our results also demonstrated that miR-181b/protein phosphatase 2A-modulated SP-1 de-phosphorylation,which mediated the EGFR-dependent VCAM-1 expression and monocyte adhesion to GBM. We also found that the EGFR-dependent VCAM-1 expression is mediated by the p38/STAT3 signaling pathway. Our study suggested that VCAM-1 is a critical modulator of EGFR-dependent interaction of monocytes with GBM,which raises the possibility of developing effective and improved therapies for GBM.Oncogene advance online publication,1 May 2017; doi:10.1038/onc.2017.129. View Publication

Mobile sensing based on the integration of microfluidic device and smartphone,so-called MS2 technology,has enabled many applications over recent years,and continues to stimulate growing interest in both research communities and industries. In particular,it has been envisioned that MS2 technology can be developed for various cell functional assays to enable basic research and clinical applications. Toward this direction,in this paper,we describe the development of a MS2-based cell functional assay for testing cell migration (the Mkit). The system is constructed as an integrated test kit,which includes microfluidic chips,a smartphone-based imaging platform,the phone apps for image capturing and data analysis,and a set of reagent and accessories for performing the cell migration assay. We demonstrated that the Mkit can effectively measure purified neutrophil and cancer cell chemotaxis. Furthermore,neutrophil chemotaxis can be tested from a drop of whole blood using the Mkit with red blood cell (RBC) lysis. The effects of chemoattractant dose and gradient profile on neutrophil chemotaxis were also tested using the Mkit. In addition to research applications,we demonstrated the effective use of the Mkit for on-site test at the hospital and for testing clinical samples from chronic obstructive pulmonary disease patient. Thus,this developed Mkit provides an easy and integrated experimental platform for cell migration related research and potential medical diagnostic applications. View Publication

The serological complement-dependent cytotoxicity crossmatch (CDC-XM) permits routine identification of anti-donor alloantibodies in the sera of allotransplant recipients. However,in a small group of recipients,antibodies below the threshold of detection may still be responsible for hyperacute rejection. For the same reason,approximately 20% of recipients develop acute rejection episodes. The flow cytometry crossmatch (FCXM) was designed to address these problems,but because of the presence of clinically insignificant antibodies (linked,non-lytic),the FCXM appears to be too sensitive yielding false-positive results. We compared FCXM with its modified version assessing cell viability (cytolytic flow cytometry crossmatch; cFCXM) using sera from previously sensitised kidney recipients. The presence of alloantibodies was detected using the Luminex platform. The cFCXM proved to be of greater sensitivity than CDC-XM,which was additionally confirmed with bead-based Luminex techniques. The cFCXM was also superior to FCXM because it distinguished lytic from non-lytic antibodies. The cFCXM was superior to assess donor specificity,sensitivity,and detection of clinically relevant lytic antibodies. View Publication

The type III family of IFNs displays immunomodulatory and antiviral activity. Each member (IFN-lambda1,-2,and -3) signals through the same heterodimeric receptor complex,which consists of the binding and signaling subunit (IL-28Ralpha) plus the IL-10Rbeta chain. Although the receptor has a wide tissue distribution,the direct effects of IFN-lambda on various immune cell subsets have not been fully characterized. We have identified high levels of IL-28Ralpha mRNA in pDC from peripheral blood and hypothesized that IFN-lambda plays an important role in pDC maturation and development. We show that stimulation of pDC with HSV or Imiquimod causes an increase in IL-28Ralpha mRNA. In these cells,IFN-lambda1 alters expression of the costimulatory molecules CD80 and ICOS-L and synergizes with IFN-alpha to up-regulate CD83. In addition,IFN-lambda1 has a variable effect on the homing molecule expression of pDC and mDC. IFN-lambda1-treated pDC display a marked difference in their ability to stimulate production of the signature cytokines IL-13,IFN-gamma,and IL-10 in a MLR. This work characterizes the variable effects of IFN-lambda on DC surface molecule expression and identifies a role in pDC activation and immunostimulatory potential. View Publication

Glatiramer acetate (GA or Copaxone) is a drug used to treat experimental autoimmune encephalomyelitis in mice and multiple sclerosis in human. Here,we describe a new mechanism of action for this drug. GA enhanced the cytolysis of human NK cells against autologous and allogeneic immature and mature monocyte-derived dendritic cells (DCs). This drug reduced the percentages of mature DCs expressing CD80,CD83,HLA-DR or HLA-I. In contrast,it did not modulate the percentages of NK cells expressing NKG2D,NKp30,or NKp44. Nonetheless,anti-NKp30 or anti-CD86 inhibited GA-enhanced human NK cell lysis of immature DCs. Hence,CD86,and NKp30 are important for NK cell lysis of immature DCs,whereas CD80,CD83,HLA-DR and HLA-I are important for the lysis of mature DCs when GA is used as a stimulus. Further,GA inhibited the release of IFN-gamma 24 h but increased the release of TNF-alpha 48 h after incubation with NK cells. View Publication

1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) can modulate immune responses,but whether it directly affects B cell function is unknown. Patients with systemic lupus erythematosus,especially those with antinuclear Abs and increased disease activity,had decreased 1,25(OH)(2)D(3) levels,suggesting that vitamin D might play a role in regulating autoantibody production. To address this,we examined the effects of 1,25(OH)(2)D(3) on B cell responses and found that it inhibited the ongoing proliferation of activated B cells and induced their apoptosis,whereas initial cell division was unimpeded. The generation of plasma cells and postswitch memory B cells was significantly inhibited by 1,25(OH)(2)D(3),although the up-regulation of genetic programs involved in B cell differentiation was only modestly affected. B cells expressed mRNAs for proteins involved in vitamin D activity,including 1 alpha-hydroxylase,24-hydroxylase,and the vitamin D receptor,each of which was regulated by 1,25(OH)(2)D(3) and/or activation. Importantly,1,25(OH)(2)D(3) up-regulated the expression of p27,but not of p18 and p21,which may be important in regulating the proliferation of activated B cells and their subsequent differentiation. These results indicate that 1,25(OH)(2)D(3) may play an important role in the maintenance of B cell homeostasis and that the correction of vitamin D deficiency may be useful in the treatment of B cell-mediated autoimmune disorders. View Publication

Background Progressive T cell decline in aged humans is associated with a deficiency of naive (TN) and central memory (TCM) T cells. We have previously reported increased tumor necrosis factor-? (TNF-?)-induced apoptosis in TN and TCM T cells in aged humans; however,the molecular basis of increased apoptosis remains to be defined. Since expression of TNF receptors (TNFRs) was reported to be comparable in young and aged,we investigated signaling events downstream of TNFRs to understand the molecular basis of increased TNF-?-induced apoptosis in aged TN and TCM CD8+ cells. Results The expression of TRAF-2 and RIP,phosphorylation of JNK,IKK?/?,and I?B?,and activation of NF-?B activation were significantly decreased in TN and TCM CD8+ cells from aged subjects as compared to young controls. Furthermore,expression of A20,Bcl-xL,cIAP1,and FLIP-L and FLIP-S was significantly decreased in TN and TCM CD8+ cells from aged subjects. Conclusions These data demonstrate that an impaired expression/function of molecules downstream TNFR signaling pathway that confer survival signals contribute to increased apoptosis of TN and TCM CD8+ cells in aged humans. View Publication

We have previously reported that an anti-human transferrin receptor IgG3-avidin fusion protein (anti-hTfR IgG3-Av) inhibits the proliferation of an erythroleukemia-cell line. We have now found that anti-hTfR IgG3-Av also inhibits the proliferation of additional human malignant B and plasma cells. Anti-hTfR IgG3-Av induces internalization and rapid degradation of the TfR. These events can be reproduced in cells treated with anti-hTfR IgG3 cross-linked with a secondary Ab,suggesting that they result from increased TfR cross-linking. Confocal microscopy of cells treated with anti-hTfR IgG3-Av shows that the TfR is directed to an intracellular compartment expressing the lysosomal marker LAMP-1. The degradation of TfR is partially blocked by cysteine protease inhibitors. Furthermore,cells treated with anti-hTfR IgG3-Av exhibit mitochondrial depolarization and activation of caspases 9,8,and 3. The mitochondrial damage and cell death can be prevented by iron supplementation,but cannot be fully blocked by a pan-caspase inhibitor. These results suggest that anti-hTfR IgG3-Av induces lethal iron deprivation,but the resulting cell death does not solely depend on caspase activation. This report provides insights into the mechanism of cell death induced by anti-TfR Abs such as anti-hTfR IgG3-Av,a molecule that may be useful in the treatment of B-cell malignancies such as multiple myeloma. View Publication

We have recently shown that proteasome inhibitor PS-341 induces apoptosis in drug-resistant multiple myeloma (MM) cells,inhibits binding of MM cells in the bone marrow microenvironment,and inhibits cytokines mediating MM cell growth,survival,drug resistance,and migration in vitro. PS-341 also inhibits human MM cell growth and prolongs survival in a SCID mouse model. Importantly,PS-341 has achieved remarkable clinical responses in patients with refractory relapsed MM. We here demonstrate molecular mechanisms whereby PS-341 mediates anti-MM activity by inducing p53 and MDM2 protein expression; inducing the phosphorylation (Ser15) of p53 protein; activating c-Jun NH(2)-terminal kinase (JNK),caspase-8,and caspase-3; and cleaving the DNA protein kinase catalytic subunit,ATM,and MDM2. Inhibition of JNK activity abrogates PS-341-induced MM cell death. These studies identify molecular targets of PS-341 and provide the rationale for the development of second-generation,more targeted therapies. View Publication

MSCs have received attention for their therapeutic potential in a number of disease states,including bone formation,diabetes,stem cell engraftment after marrow transplantation,graft-versus-host disease,and heart failure. Despite this diverse interest,the molecular signals regulating MSC trafficking to sites of injury are unclear. MSCs are known to transiently home to the freshly infarcted myocardium. To identify MSC homing factors,we determined chemokine expression pattern as a function of time after myocardial infarction (MI). We merged these profiles with chemokine receptors expressed on MSCs but not cardiac fibroblasts,which do not home after MI. This analysis identified monocyte chemotactic protein-3 (MCP-3) as a potential MSC homing factor. Overexpression of MCP-3 1 month after MI restored MSC homing to the heart. After serial infusions of MSCs,cardiac function improved in MCP-3-expressing hearts (88.7%,p textless .001) but not in control hearts (8.6%,p = .47). MSC engraftment was not associated with differentiation into cardiac myocytes. Rather,MSC engraftment appeared to result in recruitment of myofibroblasts and remodeling of the collagen matrix. These data indicate that MCP-3 is an MSC homing factor; local overexpression of MCP-3 recruits MSCs to sites of injured tissue and improves cardiac remodeling independent of cardiac myocyte regeneration. View Publication

In this study,we have investigated the hypothesis that previously reported beneficial effect of peripheral blood mononuclear cells cultured under angiogenic conditions on cardiovascular function following ischemia is not limited to EPCs but also to monocytes contained therein. We first purified and analyzed the phenotype and secretome of human and murine blood monocytes cultured under angiogenic conditions (named MDs for monocyte derivatives) and tested their effect in a mouse model of myocardial infarction (MI). FACS analysis of MDs shows that these cells express mature endothelial cell markers and that their proliferative capacity is virtually absent,consistent with their end-differentiated monocytic ontogeny. MDs secreted significant levels of HGF,IGF-1,MCP-1,and sTNFR-1 relative to their monocyte precursors. MDs were unable to form vascular networks in vitro when cultured on matrix coated flasks. Treatment of murine HL-1 cardiomyocyte cell line with MD-conditioned medium reduced their death induced by TNF-alpha,staurosporine,and oxidative stress,and this effect was dependent upon MD-derived sTNFR-1,HGF,and IGF-1. We further demonstrate that MD secretome promoted endothelial cell proliferation and capacity to form vessels in vitro and this was dependent upon MD-derived MCP-1,HGF,and IGF-1. Echocardiography analysis showed that MD myocardial implantation improved left ventricle fractional shortening of mouse hearts following MI and was associated with reduced myocardial fibrosis and enhancement of angiogenesis. Transplanted MDs and their secretome participate in preserving functional myocardium after ischemic insult and attenuate pathological remodeling. View Publication