Chaetocin: a promising new antimyeloma agent with in vitro and in vivo activity mediated via imposition of oxidative stress.
Chaetocin,a thiodioxopiperazine natural product previously unreported to have anticancer effects,was found to have potent antimyeloma activity in IL-6-dependent and -independent myeloma cell lines in freshly collected sorted and unsorted patient CD138(+) myeloma cells and in vivo. Chaetocin largely spares matched normal CD138(-) patient bone marrow leukocytes,normal B cells,and neoplastic B-CLL (chronic lymphocytic leukemia) cells,indicating a high degree of selectivity even in closely lineage-related B cells. Furthermore,chaetocin displays superior ex vivo antimyeloma activity and selectivity than doxorubicin and dexamethasone,and dexamethasone- or doxorubicin-resistant myeloma cell lines are largely non-cross-resistant to chaetocin. Mechanistically,chaetocin is dramatically accumulated in cancer cells via a process inhibited by glutathione and requiring intact/unreduced disulfides for uptake. Once inside the cell,its anticancer activity appears mediated primarily through the imposition of oxidative stress and consequent apoptosis induction. Moreover,the selective antimyeloma effects of chaetocin appear not to reflect differential intracellular accumulation of chaetocin but,instead,heightened sensitivity of myeloma cells to the cytotoxic effects of imposed oxidative stress. Considered collectively,chaetocin appears to represent a promising agent for further study as a potential antimyeloma therapeutic.
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产品号#：
18054
18054RF
21000
20119
20155
19154
19154RF
73592
产品名：
RoboSep™- S
RoboSep™ 吸头组件抛光剂
RoboSep™分选管套装（9个塑料管）
毛壳素
Pua HH et al. (JAN 2007)
The Journal of experimental medicine 204 1 25--31
A critical role for the autophagy gene Atg5 in T cell survival and proliferation.
Macroautophagy (hereafter referred to as autophagy) is a well-conserved intracellular degradation process. Recent studies examining cells lacking the autophagy genes Atg5 and Atg7 have demonstrated that autophagy plays essential roles in cell survival during starvation,in innate cell clearance of microbial pathogens,and in neural cell maintenance. However,the role of autophagy in T lymphocyte development and survival is not known. Here,we demonstrate that autophagosomes form in primary mouse T lymphocytes. By generating Atg5-/- chimeric mice,we found that Atg5-deficient T lymphocytes underwent full maturation. However,the numbers of total thymocytes and peripheral T and B lymphocytes were reduced in Atg5 chimeras. In the periphery,Atg5-/- CD8+ T lymphocytes displayed dramatically increased cell death. Furthermore,Atg5-/- CD4+ and CD8+ T cells failed to undergo efficient proliferation after TCR stimulation. These results demonstrate a critical role for Atg5 in multiple aspects of lymphocyte development and function and suggest that autophagy may be essential for both T lymphocyte survival and proliferation.
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产品号#：
19752
19752RF
19753
19753RF
19751
19751RF
产品名：
Heinzel K et al. (JAN 2007)
Journal of immunology (Baltimore,Md. : 1950) 178 2 858--68
Bone marrow-derived hemopoietic precursors commit to the T cell lineage only after arrival in the thymic microenvironment.
T lymphocytes develop in the thymus from hemopoietic precursors that commit to the T cell lineage under the influence of Notch signals. In this study,we show by single cell analyses that the most immature hemopoietic precursors in the adult mouse thymus are uncommitted and specify to the T cell lineage only after their arrival in the thymus. These precursors express high levels of surface Notch receptors and rapidly lose B cell potential upon the provision of Notch signals. Using a novel culture system with complexed,soluble Notch ligands that allows the titration of T cell lineage commitment,we find that these precursors are highly sensitive to both Delta and Jagged ligands. In contrast,their phenotypical and functional counterparts in the bone marrow are resistant to Notch signals that efficiently induce T cell lineage commitment in thymic precursors. Mechanistically,this is not due to differences in receptor expression,because early T lineage precursors,bone marrow lineage marker-negative,Sca-1-positive,c-Kit-positive and common lymphoid progenitor cells,express comparable amounts of surface Notch receptors. Our data demonstrate that the sensitivity to Notch-mediated T lineage commitment is stage-dependent and argue against the bone marrow as the site of T cell lineage commitment.
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产品号#：
03231
产品名：
MethoCult™ M3231
Pereira LE et al. (MAY 2007)
Journal of virology 81 9 4445--56
Simian immunodeficiency virus (SIV) infection influences the level and function of regulatory T cells in SIV-infected rhesus macaques but not SIV-infected sooty mangabeys.
Differences in clinical outcome of simian immunodeficiency virus (SIV) infection in disease-resistant African sooty mangabeys (SM) and disease-susceptible Asian rhesus macaques (RM) prompted us to examine the role of regulatory T cells (Tregs) in these two animal models. Results from a cross-sectional study revealed maintenance of the frequency and absolute number of peripheral Tregs in chronically SIV-infected SM while a significant loss occurred in chronically SIV-infected RM compared to uninfected animals. A longitudinal study of experimentally SIV-infected animals revealed a transient increase in the frequency of Tregs from baseline values following acute infection in RM,but no change in the frequency of Tregs occurred in SM during this period. Further examination revealed a strong correlation between plasma viral load (VL) and the level of Tregs in SIV-infected RM but not SM. A correlation was also noted in SIV-infected RM that control VL spontaneously or in response to antiretroviral chemotherapy. In addition,immunofluorescent cell count assays showed that while Treg-depleted peripheral blood mononuclear cells from RM led to a significant enhancement of CD4+ and CD8+ T-cell responses to select pools of SIV peptides,there was no detectable T-cell response to the same pool of SIV peptides in Treg-depleted cells from SIV-infected SM. Our data collectively suggest that while Tregs do appear to play a role in the control of viremia and the magnitude of the SIV-specific immune response in RM,their role in disease resistance in SM remains unclear.
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产品号#：
18557
18557RF
15809
产品名：
Fahey AJ et al. (JUN 2007)
Journal of leukocyte biology 81 6 1562--7
Reciprocal effects of IFN-beta and IL-12 on STAT4 activation and cytokine induction in T cells.
IL-12 is an immunoregulatory cytokine,which promotes Th1 cell differentiation and is a major inducer of IFN-gamma. IFN-beta,a Type I IFN used in the treatment of multiple sclerosis,has been shown to significantly increase the expression of the anti-inflammatory cytokine IL-10,a major suppressor of Th1 cytokines. The beneficial immunomodulatory effects of IFN-beta may in part be a result of its ability to suppress IL-12. However,IL-12 and IFN-beta signal via the STAT4 pathway. Our aim was to investigate the relationship between IL-12 and IFN-beta by observing the effect of prior exposure to IL-12 or IFN-beta on the ability of T cells to subsequently respond to the other cytokine. We report that IFN-beta increases IL-12-induced STAT4 phosphorylation and up-regulates IL-12 receptor beta1 and beta2 expression. However,despite this up-regulation,IFN-beta suppressed IL-12-induced IFN-gamma expression. Our results suggest that this may be a result of the parallel induction of IL-10 by IFN-beta.
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产品号#：
19053
19053RF
19052
19052RF
产品名：
EasySep™人CD8+ T细胞富集试剂盒
RoboSep™ 人CD8+ T细胞富集试剂盒含滤芯吸头
EasySep™人CD4+ T细胞富集试剂盒
RoboSep™ 人CD4+ T细胞富集试剂盒含滤芯吸头
Yonkers NL et al. (APR 2007)
Journal of immunology (Baltimore,Md. : 1950) 178 7 4436--44
TLR ligand-dependent activation of naive CD4 T cells by plasmacytoid dendritic cells is impaired in hepatitis C virus infection.
Chronic hepatitis C virus (HCV) infection is characterized by diminished numbers and function of HCV-reactive T cells and impaired responses to immunization. Because host response to viral infection likely involves TLR signaling,we examined whether chronic HCV infection impairs APC response to TLR ligand and contributes to the origin of dysfunctional T cells. Freshly purified myeloid dendritic cells (MDC) and plasmacytoid DC (PDC) obtained from subjects with chronic HCV infection and healthy controls were exposed to TLR ligands (poly(I:C),R-848,or CpG),in the presence or absence of cytokine (TNF-alpha or IL-3),and examined for indices of maturation and for their ability to activate allogeneic naive CD4 T cells to proliferate and secrete IFN-gamma. TLR ligand was observed to enhance both MDC and PDC activation of naive CD4 T cells. Although there was increased CD83 and CD86 expression on MDC from HCV-infected persons,the ability of MDC to activate naive CD4 T cells in the presence or absence of poly(I:C) or TNF-alpha did not differ between HCV-infected and healthy control subjects. In contrast,PDC from HCV-infected persons had reduced activation marker (HLA-DR) and cytokine (IFN-alpha) expression upon R-848 stimulation,and these were associated with impaired activation of naive CD4 T cells. These data indicate that an impaired PDC responsiveness to TLR ligation may play an important role in the fundamental and unexplained failure to induce new T cell responses to HCV Ags and to other new Ags as a consequence of HCV infection.
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产品号#：
15022
15062
19155
19155RF
产品名：
RosetteSep™人CD4+ T细胞富集抗体混合物
RosetteSep™人CD4+ T细胞富集抗体混合物
Billard E et al. (OCT 2007)
Infection and immunity 75 10 4980--9
Brucella suis prevents human dendritic cell maturation and antigen presentation through regulation of tumor necrosis factor alpha secretion.
Brucella is a facultative intracellular pathogen and the etiological agent of brucellosis. In some cases,human brucellosis results in a persistent infection that may reactivate years after the initial exposure. The mechanisms by which the parasite evades clearance by the immune response to chronically infect its host are unknown. We recently demonstrated that dendritic cells (DCs),which are critical components of adaptive immunity,are highly susceptible to Brucella infection and are a preferential niche for the development of the bacteria. Here,we report that in contrast to several intracellular bacteria,Brucella prevented the infected DCs from engaging in their maturation process and impaired their capacities to present antigen to naïve T cells and to secrete interleukin-12. Moreover,Brucella-infected DCs failed to release tumor necrosis factor alpha (TNF-alpha),a defect involving the bacterial protein Omp25. Exogenous TNF-alpha addition to Brucella-infected DCs restored cell maturation and allowed them to present antigens. Two avirulent mutants of B. suis,B. suis bvrR and B. suis omp25 mutants,which do not express the Omp25 protein,triggered TNF-alpha production upon DC invasion. Cells infected with these mutants subsequently matured and acquired the ability to present antigens,two properties which were dramatically impaired by addition of anti-TNF-alpha antibodies. In light of these data,we propose a model in which virulent Brucella alters the maturation and functions of DCs through Omp25-dependent control of TNF-alpha production. This model defines a specific evasion strategy of the bacteria by which they can escape the immune response to chronically infect their host.
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产品号#：
19155
19155RF
产品名：
Jia W et al. (FEB 2011)
Journal of immunology (Baltimore,Md. : 1950) 186 3 1564--74
Autophagy regulates endoplasmic reticulum homeostasis and calcium mobilization in T lymphocytes.
Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved intracellular bulk degradation pathway that plays critical roles in eliminating intracellular pathogens,presenting endogenous Ags,and regulating T lymphocyte survival and proliferation. In this study,we have investigated the role of autophagy in regulating the endoplasmic reticulum (ER) compartment in T lymphocytes. We found that ER content is expanded in mature autophagy-related protein (Atg) 7-deficient T lymphocytes. Atg7-deficient T cells stimulated through the TCR display impaired influx,but not efflux,of calcium,and ER calcium stores are increased in Atg7-deficient T cells. Treatment with the ER sarco/ER Ca(2+)-ATPase pump inhibitor thapsigargin rescues the calcium influx defect in Atg7-deficient T lymphocytes,suggesting that this impairment is caused by an intrinsic defect in ER. Furthermore,we found that the stimulation-induced redistribution of stromal interaction molecule-1,a critical event for the store-operated Ca(2+) release-activated Ca(2+) channel opening,is impaired in Atg7-deficient T cells. Together,these findings indicate that the expanded ER compartment in Atg7-deficient T cells contains increased calcium stores,and the inability of these stores to be depleted causes defective calcium influx in these cells. Our results demonstrate that autophagy plays an important role in maintaining ER and calcium homeostasis in T lymphocytes.
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产品号#：
19751
19751RF
产品名：
Zeng J et al. (MAY 2012)
The Journal of Immunology 188 9 4297--4304
Enhancing Immunostimulatory Function of Human Embryonic Stem Cell-Derived Dendritic Cells by CD1d Overexpression
Human embryonic stem cell-derived dendritic cells (hESC-DCs) may potentially provide a platform to generate off-the-shelf" therapeutic cancer vaccines. To apply hESC-DCs for cancer immunotherapy in a semiallogeneic setting�
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产品号#：
05850
05857
05870
05875
09600
09650
70024
70024.1
85850
85857
85870
85875
70025
70025.1
70025.2
70025.3
70047
70047.1
70047.2
70048
70048.1
70048.2
产品名：
StemSpan™ SFEM
StemSpan™ SFEM
冻存的人外周血Pan T细胞
冻存的人外周血Pan T细胞
mTeSR™1
mTeSR™1
冻存的人外周血单个核细胞
冻存的人外周血单个核细胞
冻存的人外周血单个核细胞
冻存的人外周血单个核细胞
Fang L et al. (MAY 2008)
The Journal of Experimental Medicine 205 5 1037--48
Essential role of TNF receptor superfamily 25 (TNFRSF25) in the development of allergic lung inflammation
We identify the tumor necrosis factor receptor superfamily 25 (TNFRSF25)/TNFSF15 pair as critical trigger for allergic lung inflammation,which is a cardinal feature of asthma. TNFRSF25 (TNFR25) signals are required to exert T helper cell 2 (Th2) effector function in Th2-polarized CD4 cells and co-stimulate interleukin (IL)-13 production by glycosphingolipid-activated NKT cells. In vivo,antibody blockade of TNFSF15 (TL1A),which is the ligand for TNFR25,inhibits lung inflammation and production of Th2 cytokines such as IL-13,even when administered days after airway antigen exposure. Similarly,blockade of TNFR25 by a dominant-negative (DN) transgene,DN TNFR25,confers resistance to lung inflammation in mice. Allergic lung inflammation-resistant,NKT-deficient mice become susceptible upon adoptive transfer of wild-type NKT cells,but not after transfer of DN TNFR25 transgenic NKT cells. The TNFR25/TL1A pair appears to provide an early signal for Th2 cytokine production in the lung,and therefore may be a drug target in attempts to attenuate lung inflammation in asthmatics.
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产品号#：
03800
03801
03802
03803
03804
03805
03806
03831
产品名：
ClonaCell™-HY杂交瘤试剂盒
ClonaCell™-HY培养基A
ClonaCell™-HY 培养基 B
ClonaCell™-HY 培养基 C
ClonaCell™-HY 培养基 D
ClonaCell™-HY 培养基 E
ClonaCell™-HY PEG
ClonaCell™-HY 液体 HAT 筛选培养基
Wu X et al. (DEC 2008)
Blood 112 12 4675--82
Alternative splicing regulates activation-induced cytidine deaminase (AID): implications for suppression of AID mutagenic activity in normal and malignant B cells.
The mutagenic enzyme activation-induced cytidine deaminase (AID) is required for immunoglobulin class switch recombination (CSR) and somatic hypermutation (SHM) in germinal center (GC) B cells. Deregulated expression of AID is associated with various B-cell malignancies and,currently,it remains unclear how AID activity is extinguished to avoid illegitimate mutations. AID has also been shown to be alternatively spliced in malignant B cells,and there is limited evidence that this also occurs in normal blood B cells. The functional significance of these splice variants remains unknown. Here we show that normal GC human B cells and blood memory B cells similarly express AID splice variants and show for the first time that AID splicing variants are singly expressed in individual normal B cells as well as malignant B cells from chronic lymphocytic leukemia patients. We further demonstrate that the alternative AID splice variants display different activities ranging from inactivation of CSR to inactivation or heightened SHM activity. Our data therefore suggest that CSR and SHM are differentially switched off by varying the expression of splicing products of AID at the individual cell level. Most importantly,our findings suggest a novel tumor suppression mechanism by which unnecessary AID mutagenic activities are promptly contained for GC B cells.
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产品号#：
21000
20119
20155
19054
19054RF
19754
19754RF
产品名：
RoboSep™- S
RoboSep™ 吸头组件抛光剂
RoboSep™分选管套装（9个塑料管）
EasySep™人B细胞富集试剂盒
RoboSep™ 人B细胞富集试剂盒含滤芯吸头
Snyder CM et al. (OCT 2008)
Immunity 29 4 650--9
Memory inflation during chronic viral infection is maintained by continuous production of short-lived, functional T cells.
During persistent murine cytomegalovirus (MCMV) infection,the T cell response is maintained at extremely high intensity for the life of the host. These cells closely resemble human CMV-specific cells,which compose a major component of the peripheral T cell compartment in most people. Despite a phenotype that suggests extensive antigen-driven differentiation,MCMV-specific T cells remain functional and respond vigorously to viral challenge. We hypothesized that a low rate of antigen-driven proliferation would account for the maintenance of this population. Instead,we found that most of these cells divided only sporadically in chronically infected hosts and had a short half-life in circulation. The overall population was supported,at least in part,by memory T cells primed early in infection,as well as by recruitment of naive T cells at late times. Thus,these data show that memory inflation is maintained by a continuous replacement of short-lived,functional cells during chronic MCMV infection.
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EasySep™小鼠TIL（CD45）正选试剂盒
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