搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

HIV up-regulates cell-surface expression of specific ligands for the activating NKG2D receptor,including ULBP-1,-2,and -3,but not MICA or MICB,in infected cells both in vitro and in vivo. However,the viral factor(s) involved in NKG2D ligand expression still remains undefined. HIV-1 Vpr activates the DNA damage/stress-sensing ATR kinase and promotes G(2) cell-cycle arrest,conditions known to up-regulate NKG2D ligands. We report here that HIV-1 selectively induces cell-surface expression of ULBP-2 in primary CD4(+) T lymphocytes by a process that is Vpr dependent. Importantly,Vpr enhanced the susceptibility of HIV-1-infected cells to NK cell-mediated killing. Strikingly,Vpr alone was sufficient to up-regulate expression of all NKG2D ligands and thus promoted efficient NKG2D-dependent NK cell-mediated killing. Delivery of virion-associated Vpr via defective HIV-1 particles induced analogous biologic effects in noninfected target cells,suggesting that Vpr may act similarly beyond infected cells. All these activities relied on Vpr ability to activate the ATR-mediated DNA damage/stress checkpoint. Overall,these results indicate that Vpr is a key determinant responsible for HIV-1-induced up-regulation of NKG2D ligands and further suggest an immunomodulatory role for Vpr that may not only contribute to HIV-1-induced CD4(+) T-lymphocyte depletion but may also take part in HIV-1-induced NK-cell dysfunction. View Publication

The mechanisms by which neutralizing antibodies inhibit Marburg virus (MARV) are not known. We isolated a panel of neutralizing antibodies from a human MARV survivor that bind to MARV glycoprotein (GP) and compete for binding to a single major antigenic site. Remarkably,several of the antibodies also bind to Ebola virus (EBOV) GP. Single-particle EM structures of antibody-GP complexes reveal that all of the neutralizing antibodies bind to MARV GP at or near the predicted region of the receptor-binding site. The presence of the glycan cap or mucin-like domain blocks binding of neutralizing antibodies to EBOV GP,but not to MARV GP. The data suggest that MARV-neutralizing antibodies inhibit virus by binding to infectious virions at the exposed MARV receptor-binding site,revealing a mechanism of filovirus inhibition. View Publication

Langerhans cells (LCs) constitute a subset of DCs that initiate immune responses in skin. Using leprosy as a model,we investigated whether expression of CD1a and langerin,an LC-specific C-type lectin,imparts a specific functional role to LCs. LC-like DCs and freshly isolated epidermal LCs presented nonpeptide antigens of Mycobacterium leprae to T cell clones derived from a leprosy patient in a CD1a-restricted and langerin-dependent manner. LC-like DCs were more efficient at CD1a-restricted antigen presentation than monocyte-derived DCs. LCs in leprosy lesions coexpress CD1a and langerin,placing LCs in position to efficiently present a subset of antigens to T cells as part of the host response to human infectious disease. View Publication

HIV-infected slow progressors (SP) represent a heterogeneous group of subjects who spontaneously control HIV infection without treatment for several years while showing moderate signs of disease progression. Under conditions that remain poorly understood,a subgroup of these subjects experience failure of spontaneous immunological and virological control. Here we determined the frequency of SP subjects who showed loss of HIV control within our Canadian Cohort of HIV(+) Slow Progressors and identified the proinflammatory cytokine IL-32 as a robust biomarker for control failure. Plasmatic levels of the proinflammatory isoforms of IL-32 (mainly β and γ) at earlier clinic visits positively correlated with the decline of CD4 T-cell counts,increased viral load,lower CD4/CD8 ratio and levels of inflammatory markers (sCD14 and IL-6) at later clinic visits. We present here a proof-of-concept for the use of IL-32 as a predictive biomarker for disease progression in SP subjects and identify IL-32 as a potential therapeutic target. View Publication

The impact of shipping temperatures and preservation media used during transport of either peripheral blood mononuclear cells (PBMCs) or Jurkat cells was assessed,in view of implementing of a proficiency testing scheme on mononuclear cell viability. Samples were analyzed before and after shipment at different temperatures (ambient temperature,dry ice,and liquid nitrogen) and in different preservation media (serum with cryoprotectant,commercial cryopreservation solution,and room temperature transport medium). Sample quality was assessed by viability assays (Trypan Blue dye exclusion,flow cytometry,Cell Analysis System cell counting (CASY)),and by ELISpot functional assay. The liquid nitrogen storage and shipment were found to be the most stable conditions to preserve cell viability and functionality. However,we show that alternative high quality shipment conditions for viable cells are dry ice shipment and commercial cryopreservation solution. These were also cost-efficient shipment conditions,satisfying the requirements of a proficiency testing scheme for viable mononuclear cells. Room temperature transport medium dramatically and adversely affected the integrity of mononuclear cells. View Publication

Adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type 1 (HTLV-1) infection,occurs in 2% to 4% of the HTLV-1 carriers with a long latent period,suggesting that additional alterations participate in the development of ATL. To characterize and identify novel markers of ATL,we examined the expression profiles of more than 12 000 genes in 8 cases of acute-type ATL using microarray. One hundred ninety-two genes containing interleukin 2 (IL-2) receptor alpha were up-regulated more than 2-fold compared with CD4(+) and CD4(+)CD45RO(+) T cells,and tumor suppressor in lung cancer 1 (TSLC1),caveolin 1,and prostaglandin D2 synthase showed increased expression of more than 30-fold. TSLC1 is a cell adhesion molecule originally identified as a tumor suppressor in the lung but lacks its expression in normal or activated T cells. We confirmed ectopic expression of the TSLC1 in all acute-type ATL cells and in 7 of 10 ATL- or HTLV-1-infected T-cell lines. Introduction of TSLC1 into a human ATL cell line ED enhanced both self-aggregation and adhesion ability to vascular endothelial cells. These results suggested that the ectopic expression of TSLC1 could provide a novel marker for acute-type ATL and may participate in tissue invasion,a characteristic feature of the malignant ATL cells. View Publication

The Plasmodium falciparum reticulocyte-binding protein homolog 5 (PfRH5) is the leading target for next-generation vaccines against the disease-causing blood-stage of malaria. However,little is known about how human antibodies confer functional immunity against this antigen. We isolated a panel of human monoclonal antibodies (mAbs) against PfRH5 from peripheral blood B cells from vaccinees in the first clinical trial of a PfRH5-based vaccine. We identified a subset of mAbs with neutralizing activity that bind to three distinct sites and another subset of mAbs that are non-functional,or even antagonistic to neutralizing antibodies. We also identify the epitope of a novel group of non-neutralizing antibodies that significantly reduce the speed of red blood cell invasion by the merozoite,thereby potentiating the effect of all neutralizing PfRH5 antibodies as well as synergizing with antibodies targeting other malaria invasion proteins. Our results provide a roadmap for structure-guided vaccine development to maximize antibody efficacy against blood-stage malaria. View Publication

Abs have been shown to be protective in passive immunotherapy of tuberculous infection using mouse experimental models. In this study,we report on the properties of a novel human IgA1,constructed using a single-chain variable fragment clone (2E9),selected from an Ab phage library. The purified Ab monomer revealed high binding affinities for the mycobacterial ?-crystallin Ag and for the human Fc?RI (CD89) IgA receptor. Intranasal inoculations with 2E9IgA1 and recombinant mouse IFN-? significantly inhibited pulmonary H37Rv infection in mice transgenic for human CD89 but not in CD89-negative littermate controls,suggesting that binding to CD89 was necessary for the IgA-imparted passive protection. 2E9IgA1 added to human whole-blood or monocyte cultures inhibited luciferase-tagged H37Rv infection although not for all tested blood donors. Inhibition by 2E9IgA1 was synergistic with human rIFN-? in cultures of purified human monocytes but not in whole-blood cultures. The demonstration of the mandatory role of Fc?RI (CD89) for human IgA-mediated protection is important for understanding of the mechanisms involved and also for translation of this approach toward development of passive immunotherapy of tuberculosis. View Publication

Mucosal-associated invariant T (MAIT) cells exhibit different characteristics from those of TCRalpha7.2- conventional T cells. They play important roles in various inflammatory diseases,including rheumatoid arthritis and inflammatory bowel disease. MAIT cells express a single T cell receptor alpha chain,TCRalpha7.2 segment associated with Jalpha33 and CDR3 with fixed length,which recognizes bacteria-derived vitamin B metabolites. However,the characteristics of MAIT cells and TCRalpha7.2+ CD161- T cells have never been compared. Here,we performed RNA sequencing to compare the properties of MAIT cells,TCRalpha7.2- conventional T cells and TCRalpha7.2+ CD161- T cells. Genome-wide transcriptomes of MAIT cells,TCRalpha7.2- conventional T cells,and TCRalpha7.2+ CD161- T cells were compared and analyzed using causal network analysis. This is the first report comparing the transcriptomes of MAIT cells,TCRalpha7.2- conventional T cells and TCRalpha7.2+ CD161- T cells. We also identified the predominant signaling pathways of MAIT cells,which differed from those of TCRalpha7.2- conventional T cells and TCRalpha7.2+ CD161- T cells,through a gene set enrichment test and upstream regulator analysis and identified the genes responsible for the characteristic MAIT cell phenotypes. Our study advances the complete understanding of MAIT biology. View Publication

Acute coronary syndromes (ACS) are precipitated by a rupture of the atherosclerotic plaque,often at the site of T cell and macrophage infiltration. Here,we show that plaque-infiltrating CD4 T cells effectively kill vascular smooth muscle cells (VSMC). VSMCs sensitive to T cell-mediated killing express the death receptor DR5 (TNF-related apoptosis-inducing ligand [TRAIL] receptor 2),and anti-TRAIL and anti-DR5 antibodies block T cell-mediated apoptosis. CD4 T cells that express TRAIL upon stimulation are expanded in patients with ACS and more effectively induce VSMC apoptosis. Adoptive transfer of plaque-derived CD4 T cells into immunodeficient mice that are engrafted with human atherosclerotic plaque results in apoptosis of VSMCs,which was prevented by coadministration of anti-TRAIL antibody. These data identify that the death pathway is triggered by TRAIL-producing CD4 T cells as a direct mechanism of VSMC apoptosis,a process which may lead to plaque destabilization. View Publication