Biologic and genetic characterization of the novel amyloidogenic lambda light chain-secreting human cell lines, ALMC-1 and ALMC-2.
Primary systemic amyloidosis (AL) is a rare monoclonal plasma cell (PC) disorder characterized by the deposition of misfolded immunoglobulin (Ig) light chains (LC) in vital organs throughout the body. To our knowledge,no cell lines have ever been established from AL patients. Here we describe the establishment of the ALMC-1 and ALMC-2 cell lines from an AL patient. Both cell lines exhibit a PC phenotype and display cytokine-dependent growth. Using a comprehensive genetic approach,we established the genetic relationship between the cell lines and the primary patient cells,and we were also able to identify new genetic changes accompanying tumor progression that may explain the natural history of this patient's disease. Importantly,we demonstrate that free lambda LC secreted by both cell lines contained a beta structure and formed amyloid fibrils. Despite absolute Ig LC variable gene sequence identity,the proteins show differences in amyloid formation kinetics that are abolished by the presence of Na(2)SO(4). The formation of amyloid fibrils from these naturally secreting human LC cell lines is unprecedented. Moreover,these cell lines will provide an invaluable tool to better understand AL,from the combined perspectives of amyloidogenic protein structure and amyloid formation,genetics,and cell biology.
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产品类型：
产品号#：
18357
18357RF
21000
20119
20155
18387
18387RF
产品名：
RoboSep™- S
RoboSep™ 吸头组件抛光剂
RoboSep™分选管套装（9个塑料管）
Lalli PN et al. (SEP 2008)
Blood 112 5 1759--66
Locally produced C5a binds to T cell-expressed C5aR to enhance effector T-cell expansion by limiting antigen-induced apoptosis.
Our recent studies have shown that immune cell-produced complement provides costimulatory and survival signals to naive CD4(+) T cells. Whether these signals are similarly required during effector cell expansion and what molecular pathways link locally produced complement to T-cell survival were not clarified. To address this,we stimulated monoclonal and polyclonal T cells in vitro and in vivo with antigen-presenting cells (APCs) deficient in the complement regulatory protein,decay accelerating factor (DAF),and/or the complement component C3. We found that T-cell expansion induced by DAF-deficient APCs was augmented with diminished T-cell apoptosis,whereas T-cell expansion induced by C3(-/-) APCs was reduced because of enhanced T-cell apoptosis. These effects were traced to locally produced C5a,which through binding to T cell-expressed C5aR,enhanced expression of Bcl-2 and prevented Fas up-regulation. The results show that C5aR signal transduction in T cells is important to allow optimal T-cell expansion,as well as to maintain naive cell viability,and does so by suppressing programmed cell death.
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Engineering a stable and selective peptide blocker of the Kv1.3 channel in T lymphocytes.
Kv1.3 potassium channels maintain the membrane potential of effector memory (T(EM)) T cells that are important mediators of multiple sclerosis,type 1 diabetes mellitus,and rheumatoid arthritis. The polypeptide ShK-170 (ShK-L5),containing an N-terminal phosphotyrosine extension of the Stichodactyla helianthus ShK toxin,is a potent and selective blocker of these channels. However,a stability study of ShK-170 showed minor pH-related hydrolysis and oxidation byproducts that were exacerbated by increasing temperatures. We therefore engineered a series of analogs to minimize the formation of these byproducts. The analog with the greatest stability,ShK-192,contains a nonhydrolyzable phosphotyrosine surrogate,a methionine isostere,and a C-terminal amide. ShK-192 shows the same overall fold as ShK,and there is no evidence of any interaction between the N-terminal adduct and the rest of the peptide. The docking configuration of ShK-192 in Kv1.3 shows the N-terminal para-phosphonophenylalanine group lying at the junction of two channel monomers to form a salt bridge with Lys(411) of the channel. ShK-192 blocks Kv1.3 with an IC(50) of 140 pM and exhibits greater than 100-fold selectivity over closely related channels. After a single subcutaneous injection of 100 microg/kg,approximately 100 to 200 pM concentrations of active peptide is detectable in the blood of Lewis rats 24,48,and 72 h after the injection. ShK-192 effectively inhibits the proliferation of T(EM) cells and suppresses delayed type hypersensitivity when administered at 10 or 100 microg/kg by subcutaneous injection once daily. ShK-192 has potential as a therapeutic for autoimmune diseases mediated by T(EM) cells.
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产品类型：
产品号#：
19051
19051RF
产品名：
EasySep™人T细胞富集试剂盒
RoboSep™ 人T细胞富集试剂盒含滤芯吸头
Popovic R et al. (APR 2009)
Blood 113 14 3314--22
Regulation of mir-196b by MLL and its overexpression by MLL fusions contributes to immortalization.
Chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene produce chimeric proteins that cause abnormal expression of a subset of HOX genes and leukemia development. Here,we show that MLL normally regulates expression of mir-196b,a hematopoietic microRNA located within the HoxA cluster,in a pattern similar to that of the surrounding 5' Hox genes,Hoxa9 and Hoxa10,during embryonic stem (ES) cell differentiation. Within the hematopoietic lineage,mir-196b is most abundant in short-term hematopoietic stem cells and is down-regulated in more differentiated hematopoietic cells. Leukemogenic MLL fusion proteins cause overexpression of mir-196b,while treatment of MLL-AF9 transformed bone marrow cells with mir-196-specific antagomir abrogates their replating potential in methylcellulose. This demonstrates that mir-196b function is necessary for MLL fusion-mediated immortalization. Furthermore,overexpression of mir-196b was found specifically in patients with MLL associated leukemias as determined from analysis of 55 primary leukemia samples. Overexpression of mir-196b in bone marrow progenitor cells leads to increased proliferative capacity and survival,as well as a partial block in differentiation. Our results suggest a mechanism whereby increased expression of mir-196b by MLL fusion proteins significantly contributes to leukemia development.
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产品类型：
产品号#：
03534
19756
19756RF
产品名：
MethoCult™ GF M3534
Wang X et al. (MAR 2009)
Journal of immunology (Baltimore,Md. : 1950) 182 6 3597--608
MEKK3 is essential for lymphopenia-induced T cell proliferation and survival.
T cell homeostasis is crucial for maintaining an efficient and balanced T cell immunity. The interaction between TCR and self peptide (sp) MHC ligands is known to be the key driving force in this process,and it is believed to be functionally and mechanistically different from that initiated by the antigenic TCR stimulation. Yet,very little is known about the downstream signaling events triggered by this TCR-spMHC interaction and how they differ from those triggered by antigenic TCR stimulation. In this study,we show that T cell conditional ablation of MEKK3,a Ser/Thr kinase in the MAPK cascade,causes a significant reduction in peripheral T cell numbers in the conditional knockout mice,but does not perturb thymic T cell development and maturation. Using an adoptive mixed transfer method,we show that MEKK3-deficient T cells are severely impaired in lymphopenia-induced cell proliferation and survival. Interestingly,the Ag-induced T cell proliferation proceeds normally in the absence of MEKK3. Finally,we found that the activity of ERK1/2,but not p38 MAPK,was attenuated during the lymphopenia-driven response in MEKK3-deficient T cells. Together,these data suggest that MEKK3 may play a crucial selective role for spMHC-mediated T cell homeostasis.
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产品类型：
产品号#：
18751
18751RF
产品名：
Maldonado RA et al. (APR 2009)
The Journal of experimental medicine 206 4 877--92
Control of T helper cell differentiation through cytokine receptor inclusion in the immunological synapse.
The antigen recognition interface formed by T helper precursors (Thps) and antigen-presenting cells (APCs),called the immunological synapse (IS),includes receptors and signaling molecules necessary for Thp activation and differentiation. We have recently shown that recruitment of the interferon-gamma receptor (IFNGR) into the IS correlates with the capacity of Thps to differentiate into Th1 effector cells,an event regulated by signaling through the functionally opposing receptor to interleukin-4 (IL4R). Here,we show that,similar to IFN-gamma ligation,TCR stimuli induce the translocation of signal transducer and activator of transcription 1 (STAT1) to IFNGR1-rich regions of the membrane. Unexpectedly,STAT1 is preferentially expressed,is constitutively serine (727) phosphorylated in Thp,and is recruited to the IS and the nucleus upon TCR signaling. IL4R engagement controls this process by interfering with both STAT1 recruitment and nuclear translocation. We also show that in cells with deficient Th1 or constitutive Th2 differentiation,the IL4R is recruited to the IS. This observation suggest that the IL4R is retained outside the IS,similar to the exclusion of IFNGR from the IS during IL4R signaling. This study provides new mechanistic cues for the regulation of lineage commitment by mutual immobilization of functionally antagonistic membrane receptors.
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EasySep™小鼠TIL（CD45）正选试剂盒
科学海报Isolation of Human CD4+CD25+Bright/Foxp3+ Regulatory T Cells Directly from Whole Blood
科学海报Cell Enrichment to Obtain Mouse NK Cell Populations By Negative Selection
产品手册小鼠细胞分选
挂图Frequencies and Percentages of Mouse Immune Cell Types List of the frequencies of over 25 immune cell types in C57BL/6 mice
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