Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

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Doublier, Sophie; Zennaro, Cristina; Musante, Luca; Spatola, Tiziana; Candiano, Giovanni; Bruschi, Maurizio; Besso, Luca; Cedrino, Massimo; Carraro, Michele; Ghiggeri, Gian Marco; Camussi, Giovanni; Lupia, Enrico

2017-01-01

CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS.

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Sophie Doublier

Full Text Available CD40/CD40 ligand (CD40L dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs. We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS, and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS, and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

Anthocyanin prevents CD40-activated proinflammatory signaling in endothelial cells by regulating cholesterol distribution.

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Xia, Min; Ling, Wenhua; Zhu, Huilian; Wang, Qing; Ma, Jing; Hou, Mengjun; Tang, Zhihong; Li, Lan; Ye, Qinyuan

2007-03-01

Intracellular tumor necrosis factor receptor-associated factors (TRAFs) translocation to lipid rafts is a key element in CD40-induced signaling. The purpose of this study was to investigate the influence of anthocyanin on CD40-mediated proinflammatory events in human endothelial cells and the underlying possible molecular mechanism. Treatment of endothelial cells with anthocyanin prevented from CD40-induced proinflammatory status, measured by production of IL-6, IL-8, and monocyte chemoattractant protein-1 through inhibiting CD40-induced nuclear factor-kappaB (NF-kappaB) activation. TRAF-2 played pivotal role in CD40-NF-kappaB pathway as TRAF-2 small interference RNA (siRNA) diminished CD40-induced NF-kappaB activation and inflammation. TRAF-2 overexpression increased CD40-mediated NF-kappaB activation. Moreover, TRAF-2 almost totally recruited to lipid rafts after stimulation by CD40 ligand and depletion of cholesterol diminished CD40-mediated NF-kappaB activation. Exposure to anthocyanin not only interrupted TRAF-2 recruitment to lipid rafts but also decreased cholesterol content in Triton X-100 insoluble lipid rafts. However, anthocyanin did not influence the interaction between CD40 ligand and CD40 receptor. Our findings suggest that anthocyanin protects from CD40-induced proinflammatory signaling by preventing TRAF-2 translocation to lipid rafts through regulation of cholesterol distribution, which thereby may represent a mechanism that would explain the anti-inflammatory response of anthocyanin.

Soluble CD40 ligand contributes to blood-brain barrier breakdown and central nervous system inflammation in multiple sclerosis and neuromyelitis optica spectrum disorder.

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Masuda, Hiroki; Mori, Masahiro; Uchida, Tomohiko; Uzawa, Akiyuki; Ohtani, Ryohei; Kuwabara, Satoshi

2017-04-15

Soluble CD40 ligand (sCD40L) is reported to disrupt the blood-brain barrier (BBB). Cerebrospinal fluid (CSF) and serum sCD40L levels were measured in 29 multiple sclerosis (MS), 29 neuromyelitis optica spectrum disorder (NMOSD), and 27 disease control (DC) patients. In MS, serum sCD40L levels were higher than in DCs and positively correlated with the CSF/serum albumin ratio (Qalb). In NMOSD, CSF sCD40L levels were significantly increased compared to DCs, and were correlated to Qalb, CSF cell counts, protein concentrations, and interleukin-6 levels. sCD40L could be involved in BBB disruption in MS, whereas it may contribute to CNS inflammation in NMOSD. Copyright © 2017 Elsevier B.V. All rights reserved.

CD30 ligand is frequently expressed in human hematopoietic malignancies of myeloid and lymphoid origin.

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Gattei, V; Degan, M; Gloghini, A; De Iuliis, A; Improta, S; Rossi, F M; Aldinucci, D; Perin, V; Serraino, D; Babare, R; Zagonel, V; Gruss, H J; Carbone, A; Pinto, A

1997-03-15

CD30 ligand (CD30L) is a type-II membrane glycoprotein capable of transducing signals leading to either cell death or proliferation through its specific counterstructure CD30. Although several lines of evidence indicate that CD30L plays a key role as a paracrine- or autocrine-acting surface molecule in the deregulated cytokine cascade of Hodgkin's disease, little is known regarding its distribution and biologic significance in other human hematopoietic malignancies. By analyzing tumor cells from 181 patients with RNA studies and immunostaining by the anti-CD30L monoclonal antibody M80, we were able to show that human hematopoietic malignancies of different lineage and maturation stage display a frequent and broad expression of the ligand. CD30L mRNA and surface protein were detected in 60% of acute myeloid leukemias (AMLs), 54% of B-lineage acute lymphoblastic leukemias (ALLs), and in a consistent fraction (68%) of B-cell lymphoproliferative disorders. In this latter group, hairy cell leukemia and high-grade B-cell non-Hodgkin's lymphoma (B-NHL) expressed a higher surface density of CD30L as compared with B-cell chronic lymphocytic leukemia and low-grade B-NHL. Purified plasmacells from a fraction of multiple myeloma patients also displayed CD30L mRNA and protein. A more restricted expression of CD30L was found in T-cell tumors that was mainly confined to neoplasms with an activated peripheral T-cell phenotype, such as T-cell prolymphocytic leukemia, peripheral T-NHL, and adult T-cell leukemia/lymphoma. In contrast, none of the T-lineage ALLs analyzed expressed the ligand. In AML, a high cellular density of CD30L was detected in French-American-British M3, M4, and M5 phenotypes, which are directly associated with the presence on tumor cells of certain surface structures, including the p55 interleukin-2 receptor alpha-chain, the alpha(M) (CD11b) chain of beta2 integrins, and the intercellular adhesion molecule-1 (CD54). Analysis of normal hematopoietic cells

Predictive value of elevated soluble CD40 ligand in patients undergoing primary angioplasty for ST-segment elevation myocardial infarction.

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Pusuroglu, Hamdi; Akgul, Ozgur; Erturk, Mehmet; Uyarel, Huseyin; Bulut, Umit; Akkaya, Emre; Buturak, Ali; Surgit, Ozgur; Fuat, Ali; Cetin, Mustafa; Yldrm, Aydn

2014-11-01

The aim of this study was to evaluate the prognostic value of soluble CD40 ligand (sCD40L) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing a primary percutaneous coronary intervention (PCI). The prognostic value of sCD40L has been documented in patients with acute coronary syndrome; however, its value in acute STEMI remains unclear. We prospectively enrolled 499 consecutive STEMI patients (397 men, 102 women) undergoing primary PCI. The study population was divided into tertiles on the basis of admission sCD40L values. The high sCD40L group (n=168) included patients with a value in the third tertile (≥0.947 mg/l) and the low sCD40L group (n=331) included patients with a value in the lower two tertiles (0.947 mg/l) is a powerful independent predictor of 1-year all-cause mortality (odds ratio: 3.68; 95% confidence interval: 1.54-8.77; P=0.003). The results of this study suggest that a high sCD40L level at admission is associated with increased in-hospital and 1-year all-cause mortality rates in patients with STEMI undergoing primary PCI.

Platelet CD40L mediates thrombotic and inflammatory processes in atherosclerosis

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Lievens, Dirk; Zernecke, Alma; Seijkens, Tom; Soehnlein, Oliver; Beckers, Linda; Munnix, Imke C. A.; Wijnands, Erwin; Goossens, Pieter; van Kruchten, Roger; Thevissen, Larissa; Boon, Louis; Flavell, Richard A.; Noelle, Randolph J.; Gerdes, Norbert; Biessen, Erik A.; Daemen, Mat J. A. P.; Heemskerk, Johan W. M.; Weber, Christian; Lutgens, Esther

2010-01-01

CD40 ligand (CD40L), identified as a costimulatory molecule expressed on T cells, is also expressed and functional on platelets. We investigated the thrombotic and inflammatory contributions of platelet CD40L in atherosclerosis. Although CD40L-deficient (Cd40l(-/-)) platelets exhibited impaired

Establishment and Identification of Chinese Hamster Ovary Cell Lines with Stable Expression of Soluble CD40 Ligands

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JIANG Hua-wei

2014-09-01

Full Text Available Objective: To establish the Chinese Hamster Ovary (CHO cell lines with stable expression of soluble CD40 ligands (sCD40L. Methods: Recombinant plasmid pIRES2-EGFP-sCD40L, enzyme digestion and sequencing identification were obtained by cloning sCD40L coding sequences into eukaryotic expression vector pIRES2-EGFP from carrier pDC316-sCD40 containing sCD40L. CHO cells were transfected by electroporation, followed by screening of resistant clones with G418, after which monoclones were obtained by limited dilution assay and multiply cultured. Flow cytometer and reverted fluorescence microscope were applied to observe the expression of green fluorescent protein, while sCD40L expression was detected by polymerase chain reaction (PCR, reverse transcription-polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA from aspects of deoxyribose nucleic acid (DNA, messenger ribonucleic acid (mRNA and protein, respectively. CHO-sCD40L was cultured together with MDA-MB-231 cells to compare the expression changes of surface molecule fatty acid synthase (Fas by flow cytometer and observe the apoptosis of MDA-MB-231 cells after Fas activated antibodies (CH-11 were added 24 h later. Results: Plasmid pIRES2-EGFP-sCD40L was successfully established, and cell lines with stable expression of sCD40L were obtained with cloned culture after CHO cell transfection, which was named as B11. Flow cytometer and reverted fluorescence microscope showed ＞90% expression of green fluorescent protein, while PCR, RT-PCR and ELISA suggested integration of sCD40L genes into cell genome DNA, transcription of sCD40L mRNA and sCD40L protein expression being (4.5±2.1 ng/mL in the supernatant of cell culture, respectively. After co-culture of B11 and MDA-MB-231 cells, the surface Fas expression of MDA-MB-231 cells was increased from (3±1.02 % to (34.8±8.75%, while the apoptosis rate 24 h after addition of CH11 from (5.4±1.32% to (20.7±5.24%, and the differences

Soluble CD40 ligand stimulates CD40-dependent activation of the β2 integrin Mac-1 and protein kinase C zeda (PKCζ in neutrophils: implications for neutrophil-platelet interactions and neutrophil oxidative burst.

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Rong Jin

Full Text Available Recent work has revealed an essential involvement of soluble CD40L (sCD40L in inflammation and vascular disease. Activated platelets are the major source of sCD40L, which has been implicated in platelet and leukocyte activation, although its exact functional impact on leukocyte-platelet interactions and the underlying mechanisms remain undefined. We aimed to determine the impact and the mechanisms of sCD40L on neutrophils. We studied neutrophil interactions with activated, surface-adherent platelets as a model for leukocyte recruitment to the sites of injury. Our data show that CD40L contributes to neutrophil firm adhesion to and transmigration across activated surface-adherent platelets, possibly through two potential mechanisms. One involves the direct interaction of ligand-receptor (CD40L-CD40, i.e., platelet surface CD40L interaction with neutrophil CD40; another involves an indirect mechanism, i.e. soluble CD40L stimulates activation of the leukocyte-specific β2 integrin Mac-1 in neutrophils and thereby further promotes neutrophil adhesion and migration. Activation of the integrin Mac-1 is known to be critical for mediating neutrophil adhesion and migration. sCD40L activated Mac-1 in neutrophils and enhanced neutrophil-platelet interactions in wild-type neutrophils, but failed to elicit such responses in CD40-deficient neutrophils. Furthermore, our data show that the protein kinase C zeta (PKCζ is critically required for sCD40L-induced Mac-1 activation and neutrophil adhesive function. sCD40L strongly stimulated the focal clustering of Mac-1 (CD11b and the colocalization of Mac-1 with PKCζ in wild-type neutrophils, but had minimal effect in CD40-deficient neutrophils. Blocking PKCζ completely inhibited sCD40L-induced neutrophil firm adhesion. Moreover, sCD40L strongly stimulates neutrophil oxidative burst via CD40-dependent activation of PI3K/NF-KB, but independent of Mac-1 and PKCζ. These findings may contribute to a better

Functional Analysis of CD28/B7 and CD40/CD40L Costimulation During the in vivo Type 2 Immune Response

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1995-10-06

Fay, T.M., Masters, S.R, Laman , J.D., and Noelle, R.J. (1994b). The role of CD40 in the regulation ofhumoral and cell-mediated immunity. Immuno...1567-1575. 187 Foy, T.M., Laman , J.D., Ledbetter, J.A., Aruff’o, A., Claassen, E., and Noelle, R.J. (1994). gp39-CD40 interaction are essential for...cystine knot motif. Cell 73,421-424. Mohan, C., Shi, Y., Laman , J.D., and Datta, S.K. (1995). Interaction between CD40 and its ligand gp39 in the

Mechanisms of Nifedipine-Downregulated CD40L/sCD40L Signaling in Collagen Stimulated Human Platelets.

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Tso-Hsiao Chen

Full Text Available The platelet-derived soluble CD40L (sCD40L release plays a critical role in the development of atherosclerosis. Nifedipine, a dihydropyridine-based L-type calcium channel blocker (CCB, has been reported to have an anti-atherosclerotic effect beyond its blood pressure-lowering effect, but the molecular mechanisms remain unclear. The present study was designed to investigate whether nifedipine affects sCD40L release from collagen-stimulated human platelets and to determine the potential role of peroxisome proliferator-activated receptor-β/-γ (PPAR-β/-γ. We found that treatment with nifedipine significantly inhibited the platelet surface CD40L expression and sCD40L release in response to collagen, while the inhibition was markedly reversed by blocking PPAR-β/-γ activity with specific antagonist such as GSK0660 and GW9662. Meanwhile, nifedipine also enhanced nitric oxide (NO and cyclic GMP formation in a PPAR-β/-γ-dependent manner. When the NO/cyclic GMP pathway was suppressed, nifedipine-mediated inhibition of sCD40L release was abolished significantly. Collagen-induced phosphorylation of p38MAPK, ERK1/2 and HSP27, matrix metalloproteinase-2 (MMP-2 expression/activity and reactive oxygen species (ROS formation were significantly inhibited by nifedipine, whereas these alterations were all attenuated by co-treatment with PPAR-β/-γ antagonists. Collectively, these results demonstrate that PPAR-β/-γ-dependent pathways contribute to nifedipine-mediated downregulation of CD40L/sCD40L signaling in activated platelets through regulation of NO/ p38MAPK/ERK1/2/HSP27/MMP-2 signalings and provide a novel mechanism regarding the anti-atherosclerotic effect of nifedipine.

CD137 is induced by the CD40 signal on chronic lymphocytic leukemia B cells and transduces the survival signal via NF-κB activation.

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Yukana Nakaima

Full Text Available CD137 is a member of the tumor necrosis factor receptor family that is expressed on activated T cells. This molecule provides a co-stimulatory signal that enhances the survival, and differentiation of cells, and has a crucial role in the development of CD8 cytotoxic T cells and anti-tumor immunity. Here we report that CD137 expression is also induced on normal or malignant human B cells by CD40 ligation by its ligand CD154. This CD137 induction was more prominent in chronic lymphocytic leukemia (CLL cells than in other types of B cells. CD137 stimulation on B cells by its ligand induced the nuclear translocation of p52 (a non-canonical NF-κB factor. In agreement with this finding, expression of the survival factor BCL-XL was upregulated. Consequently, the CD137 signal augmented the survival of CD154-stimulated CLL B cells in vitro. This unexpected induction of CD137 on B cells by CD40 signal may influence the clinical course of CLL.

CD40 Ligand Deficient C57BL/6 Mouse Is a Potential Surrogate Model of Human X-Linked Hyper IgM (X-HIGM Syndrome for Characterizing Immune Responses against Pathogens

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Catalina Lopez-Saucedo

2015-01-01

Full Text Available Individuals with X-HIGM syndrome fail to express functional CD40 ligand; consequently they cannot mount effective protective antibody responses against pathogenic bacteria. We evaluated, compared, and characterized the humoral immune response of wild type (WT and C57-CD40L deficient (C57-CD40L−/− mice infected with Citrobacter rodentium. Basal serum isotype levels were similar for IgM and IgG3 among mice, while total IgG and IgG2b concentrations were significantly lower in C57-CD40L−/− mice compared with WT. Essentially IgG1 and IgG2c levels were detectable only in WT mice. C57-CD40L−/− animals, orally inoculated with 2×109 CFU, presented several clinical manifestations since the second week of infection and eventually died. In contrast at this time point no clinical manifestations were observed among C57-CD40L−/− mice infected with 1×107 CFU. Infection was subclinical in WT mice inoculated with either bacterial dose. The serum samples from infected mice (1×107 CFU, collected at day 14 after infection, had similar C. rodentium-specific IgM titres. Although C57-CD40L−/− animals had lower IgG and IgG2b titres than WT mice, C57-CD40L−/− mice sera displayed complement-mediated bactericidal activity against C. rodentium. C. rodentium-infected C57-CD40L−/− mice are capable of producing antibodies that are protective. C57-CD40L−/− mouse is a useful surrogate model of X-HIGM syndrome for studying immune responses elicited against pathogens.

CD40-CD40 Ligand Pathway is a Major Component of Acute Neuroinflammation and Contributes to Long-term Cognitive Dysfunction after Sepsis.

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Michels, Monique; Danieslki, Lucinéia Gainski; Vieira, Andriele; Florentino, Drielly; Dall'Igna, Dhébora; Galant, Letícia; Sonai, Beatriz; Vuolo, Francieli; Mina, Franciele; Pescador, Bruna; Dominguini, Diogo; Barichello, Tatiana; Quevedo, João; Dal-Pizzol, Felipe; Petronilho, Fabrícia

2015-03-26

Sepsis-associated encephalopathy (SAE) is associated with an increased rate of morbidity and mortality. It is not understood what the exact mechanism is for the brain dysfunction that occurs in septic patients, but brain inflammation and oxidative stress are a possible theory. Such events can occur through the alteration of molecules that perpetuate the inflammatory response. Thus, it is possible to postulate that CD40 may be involved in this process. The aim of this work is to evaluate the role of CD40-CD40L pathway activation in brain dysfunction associated with sepsis in an animal model. Microglia activation induces the upregulation of CD40-CD40L, both in vitro and in vivo. The inhibition of microglia activation decreases levels of CD40-CD40L in the brain and decreases brain inflammation, oxidative damage and blood brain barrier dysfunction. Despite this, anti-CD40 treatment does not improve mortality in this model. However, it is able to improve long-term cognitive impairment in sepsis survivors. In conclusion, there is a major involvement of the CD40-CD40L signaling pathway in long-term brain dysfunction in an animal model of sepsis.

Involvement of nuclear factor κB in platelet CD40 signaling

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Hachem, Ahmed; Yacoub, Daniel; Zaid, Younes; Mourad, Walid; Merhi, Yahye

2012-01-01

Highlights: ► sCD40L induces TRAF2 association to CD40 and NF-κB activation in platelets. ► IκBα phosphorylation downstream of CD40L/CD40 signaling is independent of p38 MAPK phosphorylation. ► IκBα is required for sCD40L-induced platelet activation and potentiation of aggregation. -- Abstract: CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-κB). Given that platelets contain NF-κB, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of IκBα, which are abolished by CD40L blockade. Inhibition of IκBα phosphorylation reverses sCD40L-induced IκBα phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on IκBα phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of IκBα phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-κB activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo-inflammatory disorders.

Human B cells induce dendritic cell maturation and favour Th2 polarization by inducing OX-40 ligand

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Maddur, Mohan S.; Sharma, Meenu; Hegde, Pushpa; Stephen-Victor, Emmanuel; Pulendran, Bali; Kaveri, Srini V.; Bayry, Jagadeesh

2015-01-01

Dendritic cells (DCs) play a critical role in immune homeostasis by regulating the functions of various immune cells, including T and B cells. Notably, DCs also undergo education on reciprocal signalling by these immune cells and environmental factors. Various reports demonstrated that B cells have profound regulatory functions, although only few reports have explored the regulation of human DCs by B cells. Here we demonstrate that activated but not resting B cells induce maturation of DCs with distinct features to polarize Th2 cells that secrete interleukin (IL)-5, IL-4 and IL-13. B-cell-induced maturation of DCs is contact dependent and implicates signalling of B-cell activation molecules CD69, B-cell-activating factor receptor, and transmembrane activator and calcium-modulating cyclophilin ligand interactor. Mechanistically, differentiation of Th2 cells by B-cell-matured DCs is dependent on OX-40 ligand. Collectively, our results suggest that B cells have the ability to control their own effector functions by enhancing the ability of human DCs to mediate Th2 differentiation. PMID:24910129

CD40–CD40 Ligand Pathway Is a Major Component of Acute Neuroinflammation and Contributes to Long-term Cognitive Dysfunction after Sepsis

Science.gov (United States)

Michels, Monique; Danieslki, Lucinéia Gainski; Vieira, Andriele; Florentino, Drielly; Dall’Igna, Dhébora; Galant, Letícia; Sonai, Beatriz; Vuolo, Francieli; Mina, Franciele; Pescador, Bruna; Dominguini, Diogo; Barichello, Tatiana; Quevedo, João; Dal-Pizzol, Felipe; Petronilho, Fabrícia

2015-01-01

Sepsis-associated encephalopathy (SAE) is associated with an increased rate of morbidity and mortality. It is not understood what the exact mechanism is for the brain dysfunction that occurs in septic patients, but brain inflammation and oxidative stress are a possible theory. Such events can occur through the alteration of molecules that perpetuate the inflammatory response. Thus, it is possible to postulate that CD40 may be involved in this process. The aim of this work is to evaluate the role of CD40–CD40L pathway activation in brain dysfunction associated with sepsis in an animal model. Microglia activation induces the upregulation of CD40–CD40L, both in vitro and in vivo. The inhibition of microglia activation decreases levels of CD40–CD40L in the brain and decreases brain inflammation, oxidative damage and blood brain barrier dysfunction. Despite this, anti-CD40 treatment does not improve mortality in this model. However, it is able to improve long-term cognitive impairment in sepsis survivors. In conclusion, there is a major involvement of the CD40–CD40L signaling pathway in long-term brain dysfunction in an animal model of sepsis. PMID:25822797

Involvement of nuclear factor {kappa}B in platelet CD40 signaling

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Hachem, Ahmed [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Yacoub, Daniel [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Centre Hospitalier Universite de Montreal, 264 boul. Rene-Levesque est, Montreal, Quebec, Canada H2X 1P1 (Canada); Zaid, Younes [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Mourad, Walid [Universite de Montreal, Department of Medicine, 2900 boul. Edouard-Montpetit, Montreal, Quebec, Canada H3T 1J4 (Canada); Centre Hospitalier Universite de Montreal, 264 boul. Rene-Levesque est, Montreal, Quebec, Canada H2X 1P1 (Canada); Merhi, Yahye, E-mail: yahye.merhi@icm-mhi.org [Laboratory of Thrombosis and Hemostasis, Montreal Heart Institute, 5000 Belanger, Montreal, Quebec, Canada H1T 1C8 (Canada); Universite de Montreal, Department of Medicine, 2900 boul. Edouard-Montpetit, Montreal, Quebec, Canada H3T 1J4 (Canada)

2012-08-17

Highlights: Black-Right-Pointing-Pointer sCD40L induces TRAF2 association to CD40 and NF-{kappa}B activation in platelets. Black-Right-Pointing-Pointer I{kappa}B{alpha} phosphorylation downstream of CD40L/CD40 signaling is independent of p38 MAPK phosphorylation. Black-Right-Pointing-Pointer I{kappa}B{alpha} is required for sCD40L-induced platelet activation and potentiation of aggregation. -- Abstract: CD40 ligand (CD40L) is a thrombo-inflammatory molecule that predicts cardiovascular events. Platelets constitute the major source of soluble CD40L (sCD40L), which has been shown to potentiate platelet activation and aggregation, in a CD40-dependent manner, via p38 mitogen activated protein kinase (MAPK) and Rac1 signaling. In many cells, the CD40L/CD40 dyad also induces activation of nuclear factor kappa B (NF-{kappa}B). Given that platelets contain NF-{kappa}B, we hypothesized that it may be involved in platelet CD40 signaling and function. In human platelets, sCD40L induces association of CD40 with its adaptor protein the tumor necrosis factor receptor associated factor 2 and triggers phosphorylation of I{kappa}B{alpha}, which are abolished by CD40L blockade. Inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced I{kappa}B{alpha} phosphorylation without affecting p38 MAPK phosphorylation. On the other hand, inhibition of p38 MAPK phosphorylation has no effect on I{kappa}B{alpha} phosphorylation, indicating a divergence in the signaling pathway originating from CD40 upon its ligation. In functional studies, inhibition of I{kappa}B{alpha} phosphorylation reverses sCD40L-induced platelet activation and potentiation of platelet aggregation in response to a sub-threshold concentration of collagen. This study demonstrates that the sCD40L/CD40 axis triggers NF-{kappa}B activation in platelets. This signaling pathway plays a critical role in platelet activation and aggregation upon sCD40L stimulation and may represent an important target against thrombo

TLR5 signaling enhances the proliferation of human allogeneic CD40-activated B cell induced CD4hiCD25+ regulatory T cells.

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Ping-Lung Chan

Full Text Available Although diverse functions of different toll-like receptors (TLR on human natural regulatory T cells have been demonstrated recently, the role of TLR-related signals on human induced regulatory T cells remain elusive. Previously our group developed an ex vivo high-efficient system in generating human alloantigen-specific CD4(hiCD25(+ regulatory T cells from naïve CD4(+CD25(- T cells using allogeneic CD40-activated B cells as stimulators. In this study, we investigated the role of TLR5-related signals on the generation and function of these novel CD4(hiCD25(+ regulatory T cells. It was found that induced CD4(hiCD25(+ regulatory T cells expressed an up-regulated level of TLR5 compared to their precursors. The blockade of TLR5 using anti-TLR5 antibodies during the co-culture decreased CD4(hiCD25(+ regulatory T cells proliferation by induction of S phase arrest. The S phase arrest was associated with reduced ERK1/2 phosphorylation. However, TLR5 blockade did not decrease the CTLA-4, GITR and FOXP3 expressions, and the suppressive function of CD4(hiCD25(+ regulatory T cells. In conclusion, we discovered a novel function of TLR5-related signaling in enhancing the proliferation of CD4(hiCD25(+ regulatory T cells by promoting S phase progress but not involved in the suppressive function of human CD40-activated B cell-induced CD4(hiCD25(+ regulatory T cells, suggesting a novel role of TLR5-related signals in the generation of induced regulatory T cells.

Correlation between intravoxel incoherent motion magnetic resonance imaging derived metrics and serum soluble CD40 ligand level in an embolic canine stroke model

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Xu, Xiao Quan; Wu, Chen Jiang; Lu, Shan Shan; Gao, Qian Qian; Zu, Qing Quan; Liu, Xing Long; Shi, Hai Bin; Liu, Sheng [Dept. of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing (China)

2017-09-15

To determine the relationship between intravoxel incoherent motion (IVIM) imaging derived quantitative metrics and serum soluble CD40 ligand (sCD40L) level in an embolic canine stroke model. A middle cerebral artery occlusion model was established in 24 beagle dogs. Experimental dogs were divided into low- and high-sCD40L group according to serum sCD40L level at 4.5 hours after establishing the model. IVIM imaging was scanned at 4.5 hours after model establishment using 10 b values ranging from 0 to 900 s/mm{sup 2}. Quantitative metrics diffusion coefficient (D), pseudodiffusion coefficient (D{sup *}), and perfusion fraction (f) of ischemic lesions were calculated. Quantitative metrics of ischemic lesions were normalized by contralateral hemisphere using the following formula: normalized D = D{sub stroke} / D{sub contralateral}. Differences in IVIM metrics between the low- and high-sCD40L groups were compared using t test. Pearson's correlation analyses were performed to determine the relationship between IVIM metrics and serum sCD40L level. The high-sCD40L group showed significantly lower f and normalized f values than the low-sCD40L group (f, p < 0.001; normalized f, p < 0.001). There was no significant difference in D{sup *}, normalized D{sup *}, D, or normalized D value between the two groups (All p > 0.05). Both f and normalized f values were negatively correlated with serum sCD40L level (f, r = −0.789, p < 0.001; normalized f, r = −0.823, p < 0.001). However, serum sCD40L level had no significant correlation with D{sup *}, normalized D{sup *}, D, or normalized D (All p > 0.05). The f value derived from IVIM imaging was negatively correlated with serum sCD40L level. f value might serve as a potential imaging biomarker to assess the formation of microvascular thrombosis in hyperacute period of ischemic stroke.

Precise mapping of the CD95 pre-ligand assembly domain.

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Valérie Edmond

Full Text Available Pre-association of CD95 at the plasma membrane is mandatory for efficient death receptor signaling. This homotrimerization occurs through self-association of an extracellular domain called the pre-ligand assembly domain (PLAD. Using novel molecular and cellular tools, we confirmed that CD95-PLAD is necessary to promote CD95 multimerization and plays a pivotal role in the transmission of apoptotic signals. However, while a human CD95 mutant deleted of the previously described PLAD domain (amino acids 1 to 66 fails to interact with its wild-type counterpart and trigger autonomous cell death, deletion of amino acids 1 to 42 does not prevent homo- or hetero (human/mouse-oligomerization of CD95, and thus does not alter transmission of the apoptotic signal. Overall, these findings indicate that the region between amino acids 43 to 66 corresponds to the minimal motif involved in CD95 homotypic interaction and is necessary to convey an efficient apoptotic signal. Interfering with this PLAD may represent a new therapeutic strategy for altering CD95-induced apoptotic and non-apoptotic signals.

Increased concentrations of soluble CD40 ligand platelet in patients with primary antiphospholipidic syndrome.

Science.gov (United States)

Galicia López, Aida; Olguín Ortega, Lourdes; Saavedra, Miguel A; Méndez Cruz, René; Jimenez Flores, Rafael; García de la Peña, Maximiliano

2013-01-01

To determine the concentrations of sCD40L in patients with PAPS, and establish its association with the number of thrombosis. We included patients with PAPS and healthy controls of the same age and sex. For analysis, patients with PAPS were divided into 2 groups: 1) patients with 1 thrombosis, and 2) patients with >1 thrombosis. Soluble CD40L concentrations were determined by ELISA method. sCD40L concentrations were significantly higher in patients with PAPS compared with the controls (9.72 ng ± 11.23 ng/ml vs. 4.69 ± 4.04 ng/ml) (P=.04) There was no association between serum levels of sCD40L and the number of thrombosis (1 thrombosis: 9.81 ± 9.87 ng/ml vs 9.63 ± 12.75 ng/ml in ≥ 1thrombosis (P=.13). In women with pregnancy and abortions, (13 patients) concentrations of sCD40L were higher than in those patients without a history of abortion (26 patients) but without statically significant difference (12.11 ± 16.46 ng/ml vs. 8.80 ± 8.61 ng/ml) (P=.33). There was no correlation between levels of sCD40L and the total number of thrombosis. Patients with PAPS have higher concentrations of sCD40L compared with healthy subjects, although this is not associated with a greater number of thrombosis. Among patients with PAPS, there is a tendency to higher concentrations of sCD40L in women with pregnancy and history of abortion. Since the platelet is the main cellular source of sCD40L, is possible that this pathway plays a pathogenic role in patients with PAPS. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Enhancing the Performance of CdSe/CdS Dot-in-Rod Light-Emitting Diodes via Surface Ligand Modification.

Science.gov (United States)

Rastogi, Prachi; Palazon, Francisco; Prato, Mirko; Di Stasio, Francesco; Krahne, Roman

2018-02-14

The surface ligands on colloidal nanocrystals (NCs) play an important role in the performance of NC-based optoelectronic devices such as photovoltaic cells, photodetectors, and light-emitting diodes (LEDs). On one hand, the NC emission depends critically on the passivation of the surface to minimize trap states that can provide nonradiative recombination channels. On the other hand, the electrical properties of NC films are dominated by the ligands that constitute the barriers for charge transport from one NC to its neighbor. Therefore, surface modifications via ligand exchange have been employed to improve the conductance of NC films. However, in LEDs, such surface modifications are more critical because of their possible detrimental effects on the emission properties. In this work, we study the role of surface ligand modifications on the optical and electrical properties of CdSe/CdS dot-in-rods (DiRs) in films and investigate their performance in all-solution-processed LEDs. The DiR films maintain high photoluminescence quantum yield, around 40-50%, and their electroluminescence in the LED preserves the excellent color purity of the photoluminescence. In the LEDs, the ligand exchange boosted the luminance, reaching a fourfold increase from 2200 cd/m 2 for native surfactants to 8500 cd/m 2 for the exchanged aminoethanethiol (AET) ligands. Moreover, the efficiency roll-off, operational stability, and shelf life are significantly improved, and the external quantum efficiency is modestly increased from 5.1 to 5.4%. We relate these improvements to the increased conductivity of the emissive layer and to the better charge balance of the electrically injected carriers. In this respect, we performed ultraviolet photoelectron spectroscopy (UPS) to obtain a deeper insight into the band alignment of the LED structure. The UPS data confirm similar flat-band offsets of the emitting layer to the electron- and hole-transport layers in the case of AET ligands, which translates to

Not just a marker: CD34 on human hematopoietic stem/progenitor cells dominates vascular selectin binding along with CD44

KAUST Repository

Abu Samra, Dina Bashir Kamil; Aleisa, Fajr A; Al-Amoodi, Asma S.; Jalal Ahmed, Heba M.; Chin, Chee Jia; AbuElela, Ayman; Bergam, Ptissam; Sougrat, Rachid; Merzaban, Jasmeen

2017-01-01

CD34 is routinely used to identify and isolate human hematopoietic stem/progenitor cells (HSPCs) for use clinically in bone marrow transplantation, but its function on these cells remains elusive. Glycoprotein ligands on HSPCs help guide their migration to specialized microvascular beds in the bone marrow that express vascular selectins (E- and P-selectin). Here, we show that HSPC-enriched fractions from human hematopoietic tissue expressing CD34 (CD34pos) bound selectins, whereas those lacking CD34 (CD34neg) did not. An unbiased proteomics screen identified potential glycoprotein ligands on CD34pos cells revealing CD34 itself as a major vascular selectin ligand. Biochemical and CD34 knockdown analyses highlight a key role for CD34 in the first prerequisite step of cell migration, suggesting that it is not just a marker on these cells. Our results also entice future potential strategies to investigate the glycoforms of CD34 that discriminate normal HSPCs from leukemic cells and to manipulate CD34neg HSPC-enriched bone marrow or cord blood populations as a source of stem cells for clinical use.

Not just a marker: CD34 on human hematopoietic stem/progenitor cells dominates vascular selectin binding along with CD44

KAUST Repository

Abu Samra, Dina Bashir Kamil

2017-12-27

CD34 is routinely used to identify and isolate human hematopoietic stem/progenitor cells (HSPCs) for use clinically in bone marrow transplantation, but its function on these cells remains elusive. Glycoprotein ligands on HSPCs help guide their migration to specialized microvascular beds in the bone marrow that express vascular selectins (E- and P-selectin). Here, we show that HSPC-enriched fractions from human hematopoietic tissue expressing CD34 (CD34pos) bound selectins, whereas those lacking CD34 (CD34neg) did not. An unbiased proteomics screen identified potential glycoprotein ligands on CD34pos cells revealing CD34 itself as a major vascular selectin ligand. Biochemical and CD34 knockdown analyses highlight a key role for CD34 in the first prerequisite step of cell migration, suggesting that it is not just a marker on these cells. Our results also entice future potential strategies to investigate the glycoforms of CD34 that discriminate normal HSPCs from leukemic cells and to manipulate CD34neg HSPC-enriched bone marrow or cord blood populations as a source of stem cells for clinical use.

Can ligand addition to soil enhance Cd phytoextraction? A mechanistic model study.

Science.gov (United States)

Lin, Zhongbing; Schneider, André; Nguyen, Christophe; Sterckeman, Thibault

2014-11-01

Phytoextraction is a potential method for cleaning Cd-polluted soils. Ligand addition to soil is expected to enhance Cd phytoextraction. However, experimental results show that this addition has contradictory effects on plant Cd uptake. A mechanistic model simulating the reaction kinetics (adsorption on solid phase, complexation in solution), transport (convection, diffusion) and root absorption (symplastic, apoplastic) of Cd and its complexes in soil was developed. This was used to calculate plant Cd uptake with and without ligand addition in a great number of combinations of soil, ligand and plant characteristics, varying the parameters within defined domains. Ligand addition generally strongly reduced hydrated Cd (Cd(2+)) concentration in soil solution through Cd complexation. Dissociation of Cd complex ([Formula: see text]) could not compensate for this reduction, which greatly lowered Cd(2+) symplastic uptake by roots. The apoplastic uptake of [Formula: see text] was not sufficient to compensate for the decrease in symplastic uptake. This explained why in the majority of the cases, ligand addition resulted in the reduction of the simulated Cd phytoextraction. A few results showed an enhanced phytoextraction in very particular conditions (strong plant transpiration with high apoplastic Cd uptake capacity), but this enhancement was very limited, making chelant-enhanced phytoextraction poorly efficient for Cd.

Human CD141+ Dendritic Cell and CD1c+ Dendritic Cell Undergo Concordant Early Genetic Programming after Activation in Humanized Mice In Vivo

Directory of Open Access Journals (Sweden)

Yoshihito Minoda

2017-10-01

Full Text Available Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ hematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity, and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. Conventional dendritic cells (cDCs in mice are categorized into cDC1, which mediate T helper (Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The likely human equivalents are CD141+ DC and CD1c+ DC subsets for mouse cDC1 and cDC2, respectively, but the extent of any interspecies differences is poorly characterized. Here, we exploit the fact that human CD141+ DC and CD1c+ DC develop in humanized mice, to further explore their equivalency in vivo. Global transcriptome analysis of CD141+ DC and CD1c+ DC isolated from humanized mice demonstrated that they closely resemble those in human blood. Activation of DC subsets in vivo, with the TLR3 ligand poly I:C, and the TLR7/8 ligand R848 revealed that a core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, while poly I:C upregulated IFN-λ genes specifically by CD141+ DC. MYCL expression, known to be essential for CD8+ T cell priming by mouse DC, was specifically induced in CD141+ DC after activation. Concomitantly, CD141+ DC were superior to CD1c+ DC in their ability to prime naïve antigen-specific CD8+ T cells. Thus, CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses, respectively. In combination, these data demonstrate that humanized mice provide an attractive and tractable model to study

Expression Profiles of Ligands for Activating Natural Killer Cell Receptors on HIV Infected and Uninfected CD4⁺ T Cells.

Science.gov (United States)

Tremblay-McLean, Alexandra; Bruneau, Julie; Lebouché, Bertrand; Lisovsky, Irene; Song, Rujun; Bernard, Nicole F

2017-10-12

Natural Killer (NK) cell responses to HIV-infected CD4 T cells (iCD4) depend on the integration of signals received through inhibitory (iNKR) and activating NK receptors (aNKR). iCD4 activate NK cells to inhibit HIV replication. HIV infection-dependent changes in the human leukocyte antigen (HLA) ligands for iNKR on iCD4 are well documented. By contrast, less is known regarding the HIV infection related changes in ligands for aNKR on iCD4. We examined the aNKR ligand profiles HIV p24⁺ HIV iCD4s that maintained cell surface CD4 (iCD4⁺), did not maintain CD4 (iCD4 - ) and uninfected CD4 (unCD4) T cells for expression of unique long (UL)-16 binding proteins-1 (ULBP-1), ULBP-2/5/6, ULBP-3, major histocompatibility complex (MHC) class 1-related (MIC)-A, MIC-B, CD48, CD80, CD86, CD112, CD155, Intercellular adhesion molecule (ICAM)-1, ICAM-2, HLA-E, HLA-F, HLA-A2, HLA-C, and the ligands to NKp30, NKp44, NKp46, and killer immunoglobulin-like receptor 3DS1 (KIR3DS1) by flow cytometry on CD4 T cells from 17 HIV-1 seronegative donors activated and infected with HIV. iCD4⁺ cells had higher expression of aNKR ligands than did unCD4. However, the expression of aNKR ligands on iCD4 where CD4 was downregulated (iCD4 - ) was similar to (ULBP-1, ULBP-2/5/6, ULBP-3, MIC-A, CD48, CD80, CD86 and CD155) or significantly lower than (MIC-B, CD112 and ICAM-2) what was observed on unCD4. Thus, HIV infection can be associated with increased expression of aNKR ligands or either baseline or lower than baseline levels of aNKR ligands, concomitantly with the HIV-mediated downregulation of cell surface CD4 on infected cells.

Involvement of mitogen-activated protein kinases and NFκB in LPS-induced CD40 expression on human monocytic cells

International Nuclear Information System (INIS)

Wu Weidong; Alexis, Neil E.; Chen Xian; Bromberg, Philip A.; Peden, David B.

2008-01-01

CD40 is a costimulatory molecule linking innate and adaptive immune responses to bacterial stimuli, as well as a critical regulator of functions of other costimulatory molecules. The mechanisms regulating lipopolysaccharide (LPS)-induced CD40 expression have not been adequately characterized in human monocytic cells. In this study we used a human monocytic cell line, THP-1, to investigate the possible mechanisms of CD40 expression following LPS exposure. Exposure to LPS resulted in a dose- and time-dependent increase in CD40 expression. Further studies using immunoblotting and pharmacological inhibitors revealed that mitogen-activated protein kinases (MAPKs) and NFκB were activated by LPS exposure and involved in LPS-induced CD40 expression. Activation of MAPKs was not responsible for LPS-induced NFκB activation. TLR4 was expressed on THP-1 cells and pretreatment of cells with a Toll-like receptor 4 (TLR4) neutralizing antibody (HTA125) significantly blunted LPS-induced MAPK and NFκB activation and ensuing CD40 expression. Additional studies with murine macrophages expressing wild type and mutated TLR4 showed that TLR4 was implicated in LPS-induced ERK and NFκB activation, and CD40 expression. Moreover, blockage of MAPK and NFκB activation inhibited LPS-induced TLR4 expression. In summary, LPS-induced CD40 expression in monocytic cells involves MAPKs and NFκB

Analysis of glycoprotein E-selectin ligANDs on human and mouse marrow cells enriched for hematopoietic stem/progenitor cells

KAUST Repository

Merzaban, Jasmeen S.

2011-06-09

Although well recognized that expression of E-selectin on marrow microvessels mediates osteotropism of hematopoietic stem/progenitor cells (HSPCs), our knowledge regarding the cognate E-selectin ligand(s) on HSPCs is incomplete. Flow cytometry using E-selectin-Ig chimera (E-Ig) shows that human marrow cells enriched for HSPCs (CD34+ cells) display greater E-selectin binding than those obtained from mouse (lin-/Sca-1+/c-kit+ [LSK] cells). To define the relevant glycoprotein E-selectin ligands, lysates from human CD34+ and KG1a cells and from mouse LSK cells were immunoprecipitated using E-Ig and resolved byWestern blot using E-Ig. In both human and mouse cells, E-selectin ligand reactivity was observed at ∼ 120- to 130-kDa region, which contained two E-selectin ligands, the P-selectin glycoprotein ligand- 1 glycoform "CLA," and CD43. Human, but not mouse, cells displayed a prominent ∼ 100-kDa band, exclusively comprising the CD44 glycoform "HCELL."E-Ig reactivity was most prominent on CLA in mouse cells and on HCELL in human cells. To further assess HCELL\\'s contribution to E-selectin adherence, complementary studies were performed to silence (via CD44 siRNA) or enforce its expression (via exoglycosylation). Under physiologic shear conditions, CD44/HCELL-silenced human cells showed striking decreases (> 50%) in E-selectin binding. Conversely, enforced HCELL expression of LSK cells profoundly increased E-selectin adherence, yielding > 3-fold more marrow homing in vivo. These data define the key glycoprotein E-selectin ligands of human and mouse HSPCs, unveiling critical species-intrinsic differences in both the identity and activity of these structures. © 2011 by The American Society of Hematology.

Identification of phosphatidylserine as a ligand for the CD300a immunoreceptor

Energy Technology Data Exchange (ETDEWEB)

Nakahashi-Oda, Chigusa; Tahara-Hanaoka, Satoko; Honda, Shin-ichiro [Department of Immunology, Division of Biomedical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Japan Science and Technology Agency, CREST, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Shibuya, Kazuko [Department of Immunology, Division of Biomedical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Shibuya, Akira, E-mail: ashibuya@md.tsukuba.ac.jp [Department of Immunology, Division of Biomedical Sciences, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Japan Science and Technology Agency, CREST, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan)

2012-01-06

Highlights: Black-Right-Pointing-Pointer CD300a is a new phosphatidylserine receptor expressed on myeloid cells. Black-Right-Pointing-Pointer Phosphatidylserine delivers a signal for recruitment of SHP-1 by CD300a in mast cells. Black-Right-Pointing-Pointer The CD300a/phosphatidylserine interaction is blocked by MFG-E8 or anti-CD300a antibody. -- Abstract: CD300a is a member of CD300 family molecules consisting of seven genes on human chromosome 17 and nine genes in mouse chromosome 11. CD300a has a long cytoplasmic region containing the consensus immunoreceptor tyrosine-based inhibitory motif (ITIM) sequence. Upon crosslinking with antibodies against CD300a, CD300a mediates an inhibitory signal in myeloid cells. However, the ligand for CD300a has not been identified and the physiological role of CD300a remained unclear. Here, we demonstrate that the chimeric fusion protein of CD300a extracellular domain with the Fc portion of human IgG specifically bound phosphatidylserine (PS), which is exposed on the outer leaflet of the plasma membrane of apoptotic cells. PS binding to CD300a induced SHP-1 recruitment by CD300a in mast cells in response to LPS. These results indicated that CD300a is a new PS receptor.

Kinetics and mechanism of ligand-exchange reactions of Cd(II) chelates

Energy Technology Data Exchange (ETDEWEB)

Nivorozhkin, L.E.; Kalabin, G.A.; Nivorozhkin, A.L.; Valeev, R.B.; Minkin, V.I.

1987-03-01

Tetrahedral Cd(II) bis(5-thio(or seleno)pyrazole-4-carboxaldiminates) of types II and III have been synthesized for the first time. The kinetics of the degenerate ligand exchange and enantiomerization of the complexes obtained have been studied by dynamic /sup 111/Cd, /sup 77/Se, and /sup 1/H (s = 1/2) NMR. The rate of intramolecular enantiomerization (k = 1/tau) is more than an order of magnitude greater than the corresponding values for processes of degenerate ligand exchange (a second-order reaction) determined from the dynamics of the averaging of the /sup 111/Cd-/sup 77/Se and /sup 111/Cd-N=CH spin-spin coupling constants. The cleavage and formation processes of the Cd-Se and Cd-N bonds are isoenergetic (..delta.. G/sub 298//sup not equal to/ = 14.4 kcal/mole for chelate II with X = Se and R = CH/sub 2/C/sub 6/H/sub 5/). The free energies of activation of degenerate ligand exchange determined form the dynamics of the averaging of the /sup 111/Cd N=CH spin-spin coupling constant increase from 12.7 to 17.9 kcal/mole along the following series for R: C/sub 2/H/sub 5/ < Ar < CH/sub 2/C/sub 6/H/sub 5/ < t-C/sub 4/H/sub 9/ < cyclo-C/sub 6/H/sub 11/. Replacement of the sulfur atom in the chelate ring by selenium results in increases in the rates of ligand exchange. A mechanism of degenerate ligand exchange has been proposed.

Molecular Characterization of the Interactions between Vascular Selectins and Glycoprotein Ligands on Human Hematopoietic Stem/Progenitor Cells

KAUST Repository

Abusamra, Dina

2016-12-01

The human bone marrow vasculature constitutively expresses both E-selectin and P-selectin where they interact with the cell-surface glycan moiety, sialyl Lewis x, on circulating hematopoietic stem/progenitor cells (HSPCs) to mediate the essential tethering/rolling step. Although several E-selectin glycoprotein ligands (E-selLs) have been identified, the importance of each E-selL on human HSPCs is debatable and requires additional methodologies to advance their specific involvement. The first objective was to fill the knowledge gap in the in vitro characterization of the mechanisms used by selectins to mediate the initial step in the HSPCs homing by developing a real time immunoprecipitation-based assay on a surface plasmon resonance chip. This novel assay bypass the difficulties of purifying ligands, enables the use of natively glycosylated forms of selectin ligands from any model cell of interest and study its binding affinities under flow. We provide the first comprehensive quantitative binding kinetics of two well-documented ligands, CD44 and PSGL-1, with E-selectin. Both ligands bind monomeric E-selectin transiently with fast on- and off-rates while they bind dimeric E-selectin with remarkably slow on- and off-rates with the on-rate, but not the off-rate, is dependent on salt concentration. Thus, suggest a mechanism through which monomeric selectins mediate initial fast-on and -off binding to capture the circulating cells out of shear-flow; subsequently, tight binding by dimeric/oligomeric selectins is enabled to slow rolling significantly. The second objective is to fully identify and characterize E/P-selectin ligand candidates expressed on CD34+ HSPCs which cause enhanced migration after intravenous transplantation compared to their CD34- counterparts. CD34 is widely recognized marker of human HSPCs but its natural ligand and function on these cells remain elusive. Proteomics identified CD34 as an E-selL candidate on human HSPCs, whose binding to E

Constitutive activation of extracellular signal-regulated kinase predisposes diffuse large B-cell lymphoma cell lines to CD40-mediated cell death

DEFF Research Database (Denmark)

Hollmann, C Annette; Owens, Trevor; Nalbantoglu, Josephine

2006-01-01

CD40 promotes survival, proliferation, and differentiation of normal B cells but can cause activation-induced cell death in malignant B lymphocytes. CD40 ligand and anti-CD40 antibodies have been used successfully to induce apoptosis in lymphoma lines both in vitro and in xenograft tumor models. ...

IL-12-mediated STAT4 signaling and TCR signal strength cooperate in the induction of CD40L in human and mouse CD8+ T cells.

Science.gov (United States)

Stark, Regina; Hartung, Anett; Zehn, Dietmar; Frentsch, Marco; Thiel, Andreas

2013-06-01

CD40L is one of the key molecules bridging the activation of specific T cells and the maturation of professional and nonprofessional antigen-presenting cells including B cells. CD4(+) T cells have been regarded as the major T-cell subset that expresses CD40L upon cognate activation; however, we demonstrate here that a putative CD8(+) helper T-cell subset expressing CD40L is induced in human and murine CD8(+) T cells in vitro and in mice immunized with antigen-pulsed dendritic cells. IL-12 and STAT4-mediated signaling was the major instructive cytokine signal boosting the ability of CD8(+) T cells to express CD40L both in vitro and in vivo. Additionally, TCR signaling strength modulated CD40L expression in CD8(+) T cells after primary differentiation in vitro as well as in vivo. The induction of CD40L in CD8(+) T cells regulated by IL-12 and TCR signaling may enable CD8(+) T cells to respond autonomously of CD4(+) T cells. Thus, we propose that under proinflammatory conditions, a self-sustaining positive feedback loop could facilitate the efficient priming of T cells stimulated by high affinity peptide displaying APCs. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular Characterization of the Interactions between Vascular Selectins and Glycoprotein Ligands on Human Hematopoietic Stem/Progenitor Cells

KAUST Repository

Abu Samra, Dina Bashir Kamil

2016-01-01

The first objective was to fill the knowledge gap in the in vitro characterization of the mechanisms used by selectins to mediate the initial step in the HSPCs homing by developing a real time immunoprecipitation-based assay on a surface plasmon resonance chip. This novel assay bypass the difficulties of purifying ligands, enables the use of natively glycosylated forms of selectin ligands from any model cell of interest and study its binding affinities under flow. We provide the first comprehensive quantitative binding kinetics of two well-documented ligands, CD44 and PSGL-1, with E-selectin. Both ligands bind monomeric E-selectin transiently with fast on- and off-rates while they bind dimeric E-selectin with remarkably slow on- and off-rates with the on-rate, but not the off-rate, is dependent on salt concentration. Thus, suggest a mechanism through which monomeric selectins mediate initial fast-on and -off binding to capture the circulating cells out of shear-flow; subsequently, tight binding by dimeric/oligomeric selectins is enabled to slow rolling significantly. The second objective is to fully identify and characterize E/P-selectin ligand candidates expressed on CD34+ HSPCs which cause enhanced migration after intravenous transplantation compared to their CD34- counterparts. CD34 is widely recognized marker of human HSPCs but its natural ligand and function on these cells remain elusive. Proteomics identified CD34 as an E-selL candidate on human HSPCs, whose binding to E-selectin was confirmed using some static and flow-based assays. E-selectin binds to CD34 with an affinity comparable to the well-described E-selLs CD44/HCELL and PSGL-1. CD34 knockdown resulted in faster-rolling velocities compared to control cells especially at and above three dyne/cm2. CD34 is the first selectin ligand since PSGL-1 reported to bind E-/P-/L-selectins and likely plays a key role in directing the migration of human HSPCs to the bone marrow.

T helper-independent activation of human CD8+ cells: the role of CD28 costimulation.

Science.gov (United States)

Van Gool, S W; Zhang, Y; Kasran, A; de Boer, M; Ceuppens, J L

1996-07-01

The concept that activation of MHC class I-restricted CD8+ cells entirely depends on help from MHC class II-restricted CD4+ T cells has recently been supplemented with an alternative model in which CD8+ cells can directly be activated by MHC class I-expressing professional antigen-presenting cells (APC), which are able to deliver an accessory signal. The authors analysed the role of CD28-mediated costimulation for T helper cell-independent activation of purified human CD8+ T cells in two different in vitro models. Freshly isolated CD8+ cells could be activated (proliferation, IL-2 production and cytotoxic activity) by anti-CD3-presenting Fc gamma R+ mouse cells transfected with the human CD28 ligand, CD80, as the only accessory signal. On the other hand, activation of CD8+ cells by allogeneic MHC class I on EBV-transformed B cells, which express two different CD28 ligands, CD80 and CD86, also proceeded very efficiently (proliferation, cytotoxic activity and CD25 expression), but was either not, or only partially, blocked by anti-CD80 and anti-CD86 MoAb or CTLA-4Ig. This indicates that other costimulatory signals are also effective, and that CD28 triggering is not absolutely required for initial T-cell activation. CsA and CD80/CD86-blocking agents were synergistic in completely inhibiting activation of CD8+ cells in the MLR with allogeneic B-cell lines. This combination also induced non-responsiveness of CD8+ cells upon restimulation in the absence of blocking agents. Therefore, although professional APC can apparently provide multiple costimulatory signals for direct activation of CD8+ T cells, the signal derived from CD80/CD86 is unique in providing CsA-resistance.

A Novel de Novo Mutation in the CD40 Ligand Gene in a Patient With a Mild X-Linked Hyper-IgM Phenotype Initially Diagnosed as CVID: New Aspects of Old Diseases

Directory of Open Access Journals (Sweden)

Tábata T. França

2018-05-01

Full Text Available Mutations in the CD40 ligand (CD40L gene (CD40LG lead to X-linked hyper-IgM syndrome (X-HIGM, which is a primary immunodeficiency (PID characterized by decreased serum levels of IgG and IgA and normal or elevated IgM levels. Although most X-HIGM patients become symptomatic during the first or second year of life, during which they exhibit recurrent infections, some patients exhibit mild phenotypes, which are usually associated with hypomorphic mutations that do not abrogate protein expression or function. Here, we describe a 28-year-old man who initially presented with recurrent infections since the age of 7 years, when he exhibited meningitis caused by Cryptococcus neoformans. The patient had no family history of immunodeficiency, and based on clinical and laboratory presentation, he was initially diagnosed with common variable immunodeficiency (CVID. In subsequent years, he displayed several sporadic episodes of infection, including pneumonia, pharyngotonsillitis, acute otitis media, rhinosinusitis, fungal dermatosis, and intestinal helminthiasis. The evaluation of CD40L expression on the surface of activated CD3+CD4+ T cells from the patient showed decreased expression of CD40L. Genetic analysis revealed a novel de novo mutation consisting of a 6-nucleotide insertion in exon 1 of CD40LG, which confirmed the diagnosis of X-HIGM. In this report, we describe a novel mutation in the CD40L gene and highlight the complexities of PID diagnosis in light of atypical phenotypes and hypomorphic mutations as well as the importance of the differential diagnosis of PIDs.

Effect of ligand self-assembly on nanostructure and carrier transport behaviour in CdSe quantum dots

Energy Technology Data Exchange (ETDEWEB)

Li, Kuiying, E-mail: kuiyingli@ysu.edu.cn; Xue, Zhenjie

2014-11-14

Adjustment of the nanostructure and carrier behaviour of CdSe quantum dots (QDs) by varying the ligands used during QD synthesis enables the design of specific quantum devices via a self-assembly process of the QD core–shell structure without additional technologies. Surface photovoltaic (SPV) technology supplemented by X-ray diffractometry and infrared absorption spectroscopy were used to probe the characteristics of these QDs. Our study reveals that while CdSe QDs synthesized in the presence of and capped by thioglycolic acid, 3-mercaptopropionic acid, mercaptoethanol or α-thioglycerol ligands display zinc blende nanocrystalline structures, CdSe QDs modified by L-cysteine possess wurtzite nanocrystalline structures, because different end groups in these ligands induce distinctive nucleation and growth mechanisms. Carboxyl end groups in the ligand served to increase the SPV response of the QDs, when illuminated by hν ≥ E{sub g,nano-CdSe}. Increased length of the alkyl chains and side-chain radicals in the ligands partially inhibit photo-generated free charge carrier (FCC) transfer transitions of CdSe QDs illuminated by photon energy of 4.13 to 2.14 eV. The terminal hydroxyl group might better accommodate energy released in the non-radiative de-excitation process of photo-generated FCCs in the ligand's lowest unoccupied molecular orbital in the 300–580 nm wavelength region, when compared with other ligand end groups. - Highlights: • CdSe QDs modified by L-cysteine possess wurtzite nanocrystalline structures. • Carboxyl end groups in the ligand serve to increase the SPV response of CdSe QDs. • Terminal hydroxyl group in the ligand might accommodate non-radiative de-excitation process in CdSe QDs. • Increased length of the alkyl chains and side-chain radicals in the ligands partially inhibit carriers transport of CdSe QDs.

Immunohistochemical Expression and Prognostic Significance of CD97 and its Ligand DAF in Human Cervical Squamous Cell Carcinoma.

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He, Ying; Wang, Wei; Xu, Lian; Li, Li; Liu, Juan; Feng, Min; Bu, Hong

2015-09-01

Accumulating evidences had demonstrated that the CD97, a member of the epidermal growth factor 7-transmembrane family, and its cellular ligand decay accelerating factor (DAF) both play important roles in tumor dedifferentiation, migration, invasiveness, and metastasis. However, the roles of CD97 and DAF in human cervical squamous cell carcinoma (CSCC) have not been investigated. The purpose of this study was to observe the expression profile of CD97 and DAF in CSCC and evaluate their clinical significance. Immunohistochemistry was used to investigate the expression of CD97 and DAF proteins in 97 patients with CSCC and 53 patients with cervical intraepithelial neoplasia, a precursor lesion of CSCC. CD97 and DAF were absent or only weakly expressed in the normal epithelium of the cervix but were present in 83.5% (81/97) and 90.7% (88/97) of CSCC samples, respectively. Overexpression of CD97 was significantly associated with a high International Federation of Gynecology and Obstetrics stage (P=0.010) and lymph node metastasis (P=0.026). The majority of CSCCs, irrespective of staging/grading classification, displayed strong DAF immunostaining. Kaplan-Meier survival analysis revealed that overexpression of CD97 was associated with a worse prognosis. Multivariate analyses showed that the International Federation of Gynecology and Obstetrics stage (P=0.000), lymph node metastasis (P=0.004), and CD97 expression (P=0.040) were independent risk factors for overall survival. The present study suggested that the expressions of CD97 and DAF were both upregulated in CSCC. The expression level of CD97 in CSCC was associated with the severity of the tumor. Furthermore, CD97 might be an independent poor prognostic factor for CSCC patients.

Study on the optical properties of CdSe QDs with different ligands in specific matrix

International Nuclear Information System (INIS)

Lin Wei; Zou Wei; Du Zhongjie; Li Hangquan; Zhang Chen

2013-01-01

Different ligand structures of CdSe quantum dots were designed and synthesized for the specific matrix and the effect of the ligands on the photoluminescence and optical properties were further investigated. Ligand exchange reaction was used to synthesize thioglycolic acid-capped CdSe QDs and the process was characterized by FT-IR and titration. The influence of environmental pH value and storing time on the properties of thioglycolic acid-capped CdSe QDs in aqueous solution were studied by absorption and photoluminescence spectra. It was found that alkaline environment was more beneficial for the application of CdSe QDs. Therefore, the amino ligands with different molecular weight were grafted onto CdSe QDs for improving the compatibility with epoxy matrix and then amino-capped CdSe QDs/epoxy nanocomposites were fabricated. The morphologies and properties of the nanocomposites were characterized by DLS, HR-TEM, UV–Vis spectra, and photoluminescence spectra. As a result, amino ligands with short-molecular chain-capped CdSe QDs/epoxy nanocomposites exhibited good dispersion, high transparency and photoluminescence, and would be suitable for potential application in light-emitting diode device.

Immune regulation by CD40-CD40-l interactions - 2; Y2K update.

Science.gov (United States)

van Kooten, C

2000-11-01

CD40 is a cell surface receptor, which belongs to the TNF-R family, and which was first identified and functionally characterized on B lymphocytes. However, in recent years it has become clear that CD40 is expressed much broader, including expression on monocytes, dendritic cells, endothelial cells and epithelial cells. Therefore it is now thought that CD40 plays a more general role in immune regulation. The present paper reviews recent developments in this field of research, with main emphasis on CD40 signal transduction and on in vivo functions of CD40/CD40-L interactions.

The multi-functionality of CD40L and its receptor CD40 in atherosclerosis

NARCIS (Netherlands)

Lievens, Dirk; Eijgelaar, Wouter J.; Biessen, Erik A. L.; Daemen, Mat J. A. P.; Lutgens, Esther

2009-01-01

Disrupting the CD40-CD40L co-stimulatory pathway reduces atherosclerosis and induces a stable atherosclerotic plaque phenotype that is low in inflammation and high in fibrosis. Therefore, inhibition of the CD40-CD40L pathway is an attractive therapeutic target to reduce clinical complications of

Introduction of OX40 ligand into lymphoma cells elicits anti-lymphoma immunity in vivo.

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Kaneko, Hitomi; Hori, Toshiyuki; Yanagita, Soshi; Kadowaki, Norimitsu; Uchiyama, Takashi

2005-03-01

OX40, a member of the TNF receptor superfamily, and its ligand (OX40L) play crucial roles in induction and maintenance of integrated T cell immune response. Engagement of OX40L delivers a costimulatory signal to T cells. In this study, we investigated whether inoculation of OX40L-transfected EL4, a murine T cell lymphoma cell line, could induce anti-lymphoma immunity in mice. Female C57BL/6 mice were inoculated with 1 x 10(5) cells of parental EL4, OX40L-transfected EL4 (EL4-OX40L), or mock control vector-transfected EL4 (EL4-mock), and then the tumor size, overall survival, CTL activity of spleen cells, and the immunohistochemistry were compared. While both parental EL4 and EL4-mock grew rapidly, EL4-OX40L was rejected or grew slower than parental EL4 or EL4-mock. Pretreatment of mice with either anti-CD4 or anti-CD8 mAb accelerated the growth of EL4-OX40L, suggesting that both CD4+ and CD8+ T cells were involved in anti-lymphoma immunity. The immunohistochemical study revealed the infiltration of CD8+ T cells into the tumor of EL4-OX40L. In vitro CTL assay demonstrated that spleen cells of mice that had rejected EL4-OX40L had significant cytotoxic activity against parental EL4. The gene transfer of OX40L into lymphoma cells is an eligible and efficient modality to induce anti-lymphoma immunity.

Metabolic Adaptation of Human CD4+ and CD8+ T-Cells to T-Cell Receptor-Mediated Stimulation

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Nicholas Jones

2017-11-01

Full Text Available Linking immunometabolic adaptation to T-cell function provides insight for the development of new therapeutic approaches in multiple disease settings. T-cell activation and downstream effector functions of CD4+ and CD8+ T-cells are controlled by the strength of interaction between the T-cell receptor (TCR and peptides presented by human leukocyte antigens (pHLA. The role of TCR–pHLA interactions in modulating T-cell metabolism is unknown. Here, for the first time, we explore the relative contributions of the main metabolic pathways to functional responses in human CD4+ and CD8+ T-cells. Increased expression of hexokinase II accompanied by higher basal glycolysis is demonstrated in CD4+ T-cells; cytokine production in CD8+ T-cells is more reliant on oxidative phosphorylation. Using antigen-specific CD4+ and CD8+ T-cell clones and altered peptide ligands, we demonstrate that binding affinity tunes the underlying metabolic shift. Overall, this study provides important new insight into how metabolic pathways are controlled during antigen-specific activation of human T-cells.

COMPARATIVE ANALYSIS OF SOLUBLE OF CD40 LIGAND LEVELS IN HEART RECIPIENTS TREATED WITH CYCLOSPORINE A AND TACROLIMUS

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O. P. Shevchenko

2012-01-01

Full Text Available Soluble form of CD40L is platelet activating factor, which is a marker of inflammation and thrombosis. Elevated levels of sCD40L before the heart transplantation are associated with the risk of early development of cardiova- scular complications. The study included 54 patients who had received heart transplants. All recipients received a triple heart immu- nosuppressive therapy, including methylprednisolone, mycophenolate mofetil and cyclosporine A (20 recipients or methylprednisolone, mycophenolate mofetil and tacrolimus (34 recipients. Patients were not differed by age, gender, etiology of heart failure before heart transplantation (p > 0,05. In the first group of transplant recipients, the relative risk of cardiovascular events with high sCD40L levels before transplantation was 3 2 (95% CI 1,4; 12,0. In the second group of recipients, respectively, 2.69 (95% CI 1,1; 8,5. SCD40L level after heart transplan- tation was significantly higher for patients receiving cyclosporine (P < 0.05. Increasing concentrations of sCD40L are associated with a higher incidence of cardiovascular complications. 

Human innate responses and adjuvant activity of TLR ligands in vivo in mice reconstituted with a human immune system.

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Cheng, Liang; Zhang, Zheng; Li, Guangming; Li, Feng; Wang, Li; Zhang, Liguo; Zurawski, Sandra M; Zurawski, Gerard; Levy, Yves; Su, Lishan

2017-10-27

TLR ligands (TLR-Ls) represent a class of novel vaccine adjuvants. However, their immunologic effects in humans remain poorly defined in vivo. Using a humanized mouse model with a functional human immune system, we investigated how different TLR-Ls stimulated human innate immune response in vivo and their applications as vaccine adjuvants for enhancing human cellular immune response. We found that splenocytes from humanized mice showed identical responses to various TLR-Ls as human PBMCs in vitro. To our surprise, various TLR-Ls stimulated human cytokines and chemokines differently in vivo compared to that in vitro. For example, CpG-A was most efficient to induce IFN-α production in vitro. In contrast, CpG-B, R848 and Poly I:C stimulated much more IFN-α than CpG-A in vivo. Importantly, the human innate immune response to specific TLR-Ls in humanized mice was different from that reported in C57BL/6 mice, but similar to that reported in nonhuman primates. Furthermore, we found that different TLR-Ls distinctively activated and mobilized human plasmacytoid dendritic cells (pDCs), myeloid DCs (mDCs) and monocytes in different organs. Finally, we showed that, as adjuvants, CpG-B, R848 and Poly I:C can all enhance antigen specific CD4 + T cell response, while only R848 and Poly I:C induced CD8 + cytotoxic T cells response to a CD40-targeting HIV vaccine in humanized mice, correlated with their ability to activate human mDCs but not pDCs. We conclude that humanized mice serve as a highly relevant model to evaluate and rank the human immunologic effects of novel adjuvants in vivo prior to testing in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

Human CD34+ cells engineered to express membrane-bound tumor necrosis factor-related apoptosis-inducing ligand target both tumor cells and tumor vasculature.

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Lavazza, Cristiana; Carlo-Stella, Carmelo; Giacomini, Arianna; Cleris, Loredana; Righi, Marco; Sia, Daniela; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Francolini, Maura; Gloghini, Annunziata; Carbone, Antonino; Formelli, Franca; Gianni, Alessandro M

2010-03-18

Adenovirus-transduced CD34+ cells expressing membrane-bound tumor necrosis factor-related apoptosis-inducing ligand (CD34-TRAIL+ cells) exert potent antitumor activity. To further investigate the mechanism(s) of action of CD34-TRAIL+ cells, we analyzed their homing properties as well as antitumor and antivascular effects using a subcutaneous myeloma model in immunodeficient mice. After intravenous injection, transduced cells homed in the tumor peaking at 48 hours when 188 plus or minus 25 CD45+ cells per 10(5) tumor cells were detected. Inhibition experiments showed that tumor homing of CD34-TRAIL+ cells was largely mediated by vascular cell adhesion molecule-1 and stromal cell-derived factor-1. Both CD34-TRAIL+ cells and soluble (s)TRAIL significantly reduced tumor volume by 40% and 29%, respectively. Computer-aided analysis of TdT-mediated dUTP nick end-labeling-stained tumor sections demonstrated significantly greater effectiveness for CD34-TRAIL+ cells in increasing tumor cell apoptosis and necrosis over sTRAIL. Proteome array analysis indicated that CD34-TRAIL+ cells and sTRAIL activate similar apoptotic machinery. In vivo staining of tumor vasculature with sulfosuccinimidyl-6-(biotinamido) hexanoate-biotin revealed that CD34-TRAIL+ cells but not sTRAIL significantly damaged tumor vasculature, as shown by TdT-mediated dUTP nick end-labeling+ endothelial cells, appearance of hemorrhagic areas, and marked reduction of endothelial area. These results demonstrate that tumor homing of CD34-TRAIL+ cells induces early vascular disruption, resulting in hemorrhagic necrosis and tumor destruction.

Enhancement of the priming efficacy of DNA vaccines encoding dendritic cell-targeted antigens by synergistic toll-like receptor ligands

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Kornbluth Richard S

2009-08-01

Full Text Available Abstract Background Targeting of protein antigens to dendritic cells (DC via the DEC205 receptor enhances presentation of antigen-derived peptides on MHC-I and MHC-II molecules and, in the presence of costimulatory signals, antigen-specific immune responses. The immunogenicity and efficacy of DNA vaccination can also be enhanced by fusing the encoded antigen to single chain antibodies directed against DEC205. To further improve this strategy, we evaluated different toll-like receptor ligands (TLR and CD40 ligands (CD40L as adjuvants for DNA vaccines encoding a DEC205-single-chain antibody fused to the ovalbumin model antigen or HIV-1 Gag and assessed the priming efficacy of DNA in a DNA prime adenoviral vector boost immunization regimen. Results Mice were primed with the adjuvanted DEC-205 targeted DNA vaccines and boosted with adenoviral vectors encoding the same antigens. CD8+ T cell responses were determined after the adenoviral booster immunization, to determine how well the different DNA immunization regimens prime for the adenoviral boost. In the absence of adjuvants, targeting of DNA-encoded ovalbumin to DCs suppressed CD8+ T-cell responses after the adenoviral booster immunization. CD8+ T-cell responses to the DEC205 targeted DNA vaccines increased only slightly by adding either the TLR-9 ligand CpG, the TLR-3 ligand Poly I:C, or CD40 ligand expression plasmids. However, the combination of both TLR-ligands led to a strong enhancement of CD8+ T-cell responses compared to a non-targeted DNA vaccine. This finding was confirmed using HIV Gag as antigen. Conclusion Although DNA prime adenoviral vector boost immunizations belong to the strongest inducers of cytotoxic T cell responses in different animal models and humans, the CD8+ T cell responses can be further improved by targeting the DNA encoded antigen to DEC205 in the presence of synergistic TLR ligands CpG and Poly I:C.

The role of CD40 expression in dendritic cells in cancer biology; a systematic review.

Science.gov (United States)

Lee, Gui Han; Askari, Alan; Malietzis, George; Bernardo, David; Clark, Susan K; Knight, Stella C; Al-Hassi, Hafid Omar

2014-01-01

for further studies on the role of CD40-CD40 ligand pathway to inform cancer treatment.

Increased Levels of Oxidative Stress Markers, Soluble CD40 Ligand, and Carotid Intima-Media Thickness Reflect Acceleration of Atherosclerosis in Male Patients with Ankylosing Spondylitis in Active Phase and without the Classical Cardiovascular Risk Factors

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Agata Stanek

2017-01-01

Full Text Available Objective. The primary aim of the study was to assess levels of oxidative stress markers, soluble CD40 ligand (sCD40L, serum pregnancy-associated plasma protein-A (PAPP-A, and placental growth factor (PlGF as well as carotid intima-media thickness (IMT in patients with ankylosing spondylitis (AS with active phase without concomitant classical cardiovascular risk factors. Material and methods. The observational study involved 96 male subjects: 48 AS patients and 48 healthy ones, who did not differ significantly regarding age, BMI, comorbid disorders, and distribution of classical cardiovascular risk factors. In both groups, we estimated levels of oxidative stress markers, lipid profile, and inflammation parameters as well as sCD40L, serum PAPP-A, and PlGF. In addition, we estimated carotid IMT in each subject. Results. The study showed that markers of oxidative stress, lipid profile, and inflammation, as well as sCD40L, PlGF, and IMT, were significantly higher in the AS group compared to the healthy group. Conclusion. Our results demonstrate that ankylosing spondylitis may be associated with increased risk for atherosclerosis.

Abnormal proliferation of CD4- CD8+ gammadelta+ T cells with chromosome 6 anomaly: role of Fas ligand expression in spontaneous regression of the cells.

Science.gov (United States)

Ichikawa, N; Kitano, K; Ito, T; Nakazawa, T; Shimodaira, S; Ishida, F; Kiyosawa, K

1999-04-01

We report a case of granular lymphocyte proliferative disorder accompanied with hemolytic anemia and neutropenia. Phenotypes of the cells were T cell receptor gammadelta+ CD3+ CD4- CD8+ CD16+ CD56- CD57-. Southern blot analysis of T cell receptor beta and gamma chains demonstrated rearranged bands in both. Chromosomal analysis after IL-2 stimulation showed deletion of chromosome 6. Sorted gammadelta+ T cells showed an increase in Fas ligand expression compared with the levels in sorted alphabeta+ T cells. The expression of Fas ligand on these gammadelta+ T cells increased after IL-2 stimulation. The patient's anemia improved along with a decrease in granular lymphocyte count and disappearance of the abnormal karyotype without treatment. The expression of Fas ligand may be involved in spontaneous regression of granular lymphocyte proliferation with hemolytic anemia.

A potent adjuvant effect of a CD1d-binding NKT cell ligand in human immune system mice.

Science.gov (United States)

Li, Xiangming; Huang, Jing; Kaneko, Izumi; Zhang, Min; Iwanaga, Shiroh; Yuda, Masao; Tsuji, Moriya

2017-01-01

A CD1d-binding invariant natural killer T (iNKT)-cell stimulatory glycolipid, namely 7DW8-5, is shown to enhance the efficacy of radiation-attenuated sporozoites (RAS)-based malaria vaccine in mice. In the current study, we aim to determine whether 7DW8-5 can display a potent adjuvant effect in human immune system (HIS) mice. HIS-A2/hCD1d mice, which possess both functional human iNKT cells and CD8+ T cells, were generated by the transduction of NSG mice with adeno-associated virus serotype 9 expressing genes that encode human CD1d molecules and HLA-A*0201, followed by the engraftment of human hematopoietic stem cells. The magnitudes of human iNKT-cell response against 7DW8-5 and HLA-A*0201-restricted human CD8+ T-cell response against a human malaria antigen in HIS-A2/hCD1d mice were determined by using human CD1d tetramer and human HLA-A*0201 tetramer, respectively. We found that 7DW8-5 stimulates human iNKT cells in HIS-A2/hCD1d mice, as well as those derived from HIS-A2/hCD1d mice in vitro. We also found that 7DW8-5 significantly increases the level of a human malarial antigen-specific HLA-A*0201-restricted human CD8+ T-cell response in HIS-A2/hCD1d mice. Our study indicates that 7DW8-5 can display a potent adjuvant effect on RAS vaccine-induced anti-malarial immunity by augmenting malaria-specific human CD8+ T-cell response.

Long term influence of regular intake of high dose n-3 fatty acids on CD40-ligand, pregnancy-associated plasma protein A and matrix metalloproteinase-9 following acute myocardial infarction.

Science.gov (United States)

Aarsetøy, Hildegunn; Brügger-Andersen, Trygve; Hetland, Øyvind; Grundt, Heidi; Nilsen, Dennis W T

2006-02-01

Pregnancy-associated plasma protein A (PAPP-A) and matrix metalloproteinase 9 (MMP-9), both zinc-binding endopeptidases, are abundantly expressed in ruptured and eroded plaques in patients with acute coronary syndromes (ACS). The adhesion molecule CD-40 ligand (CD40L), expressed on activated platelets and T-lymphocytes, can activate metalloproteinases and thereby promote plaque-rupture. N-3 fatty acids, through their anti-inflammatory and anti-thrombotic properties, might reduce the levels of these proatherosclerotic markers and thereby the development of ACS. 300 patients were randomized on day 4 to 6 following an acute myocardial infarction (MI) to receive either 4 g of n-3 fatty acids or a similar daily dose of corn oil for at least one year. We compared levels of PAPP-A, MMP-9 and sCD-40 L at baseline and 12 months in each group, and also looked for inter-group changes. In the omega-3 group, the median level of PAPP-A rose from 0.47 mU/l to 0.56 mU/l (p < 0.001). In the same group, sCD-40 L decreased from a mean baseline value of 5.19 ng/ml to 2.45 ng/ml (p < 0.001) and MMP-9 decreased nonsignificantly from 360.50 ng/ml to 308.00 ng/ml. Corresponding values for the corn oil group were 0.54 mU/l to 0.59 mU/l for PAPP-A (p = 0.007), 5.27 ng/ml to 2.84 ng/ml for sCD-40 L (p < 0.001) and 430.00 ng/ml to 324.00 ng/ml for MMP-9 (p = ns), respectively. In conclusion; both interventions resulted in a significant rise in PAPP-A, a significant decrease in sCD40L and a non-significant decrease in MMP-9 after 12 months of treatment in MI survivors. No inter-group differences were noted.

Prevention of carrageenan-induced pleurisy in mice by anti-CD30 ligand monoclonal antibody

DEFF Research Database (Denmark)

Di Paola, Rosanna; Di Marco, Roberto; Mazzon, Emanuela

2004-01-01

CD30 ligand (CD30L) and its receptor CD30 are members of the tumor necrosis factor (TNF) and TNF receptor superfamilies that play a major role in inflammation and immune regulation. To gain insight into the in vivo role of CD30L/CD30 in inflammatory diseases, we have used carrageenan (CAR)-induce...

Generation of Affibody ligands binding interleukin-2 receptor alpha/CD25.

Science.gov (United States)

Grönwall, Caroline; Snelders, Eveline; Palm, Anna Jarelöv; Eriksson, Fredrik; Herne, Nina; Ståhl, Stefan

2008-06-01

Affibody molecules specific for human IL-2Ralpha, the IL-2 (interleukin-2) receptor alpha subunit, also known as CD25, were selected by phage-display technology from a combinatorial protein library based on the 58-residue Protein A-derived Z domain. The IL-2R system plays a major role in T-cell activation and the regulation of cellular immune responses. Moreover, CD25 has been found to be overexpressed in organ rejections, a number of autoimmune diseases and T-cell malignancies. The phage-display selection using Fc-fused target protein generated 16 unique Affibody molecules targeting CD25. The two most promising binders were characterized in more detail using biosensor analysis and demonstrated strong and selective binding to CD25. Kinetic biosensor analysis revealed that the two monomeric Affibody molecules bound to CD25 with apparent affinities of 130 and 240 nM respectively. The Affibody molecules were, on biosensor analysis, found to compete for the same binding site as the natural ligand IL-2 and the IL-2 blocking monoclonal antibody 2A3. Hence the Affibody molecules were assumed to have an overlapping binding site with IL-2 and antibodies targeting the IL-2 blocking Tac epitope (for example, the monoclonal antibodies Daclizumab and Basiliximab, both of which have been approved for therapeutic use). Furthermore, immunofluorescence microscopy and flow-cytometric analysis of CD25-expressing cells demonstrated that the selected Affibody molecules bound to CD4+ CD25+ PMBCs (peripheral-blood mononuclear cells), the IL-2-dependent cell line NK92 and phytohaemagglutinin-activated PMBCs. The potential use of the CD25-binding Affibody molecules as targeting agents for medical imaging and for therapeutic applications is discussed.

Molecular characterization of the haptoglobin.hemoglobin receptor CD163. Ligand binding properties of the scavenger receptor cysteine-rich domain region

DEFF Research Database (Denmark)

Madsen, Mette; Møller, Holger J; Nielsen, Marianne Jensby

2004-01-01

binding to SRCR domain 3 exhibited effective inhibition of ligand binding. Furthermore, analysis of purified native CD163 revealed that proteolytic cleavage in SRCR domain 3 inactivates ligand binding. Calcium protects against cleavage in this domain. Analysis of the calcium sensitivity of ligand binding...... to CD163 demonstrated that optimal ligand binding requires physiological plasma calcium concentrations, and an immediate ligand release occurs at the low calcium concentrations measured in acidifying endosomes. In conclusion, SRCR domain 3 of CD163 is an exposed domain and a critical determinant...... for the calcium-sensitive coupling of haptoglobin.hemoglobin complexes....

The role of ligands in the optical and electronic spectra of CdSe nanoclusters

Energy Technology Data Exchange (ETDEWEB)

Kilina, Svletana [Los Alamos National Laboratory; Sergei, Ivanov A [Los Alamos National Laboratory; Victor, Klimov I [Los Alamos National Laboratory; Sergei, Tretiak [Los Alamos National Laboratory

2008-01-01

We investigate the impact of ligands on morphology, electronic structure, and optical response of the Cd33Se33 cluster, which already overlapps in size with the smallest synthesized CdSe quantum dots (QDs). Our Density Functional Theory (DFT) calculations demonstrate significant surface reorganization both for the bare cluster and for the cluster capped by amine and phosphine oxide ligand models. We observe strong surface-ligand interactions leading to substantial charge redistribution and polarization effects on the surface. This effect results in the appearance of hybridized states, where the electronic density is spread over the cluster and the ligands. Neither the ligand's nor hybridized molecular orbitals appear as trap states inside or near the band gap of the QD. Instead, being optically dark, dense hybridized states from the edges of the valence and the conduction bands could open new relaxation channels for high energy photoexcitations. Comparing quantum dots passivated by different ligands, we found that hybridized states are denser in at the edge of the conduction band of the cluster ligated with phosphine oxide molecules than that with primary amines. Such a different manifestation of ligand binding may potentially lead to the faster electron relaxation in dots passivated by phosphine oxide than by amine ligands, which is in agreement with experimental data.

Safety and biodistribution of a double-deleted oncolytic vaccinia virus encoding CD40 ligand in laboratory Beagles

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Karoliina Autio

2014-01-01

Full Text Available We evaluated adverse events, biodistribution and shedding of oncolytic vaccinia virus encoding CD40 ligand in two Beagles, in preparation for a phase 1 trial in canine cancer patients. Dog 1 received one dose of vaccinia virus and was euthanized 24 hours afterwards, while dog 2 received virus four times once weekly and was euthanized 7 days after that. Dogs were monitored for adverse events and underwent a detailed postmortem examination. Blood, saliva, urine, feces, and organs were collected for virus detection. Dog 1 had mild fever and lethargy while dog 2 experienced a possible seizure 5.5 hours after first virus administration. Viral DNA declined quickly in the blood after virus administration in both dogs but was still detectable 1 week later by quantitative polymerase chain reaction. Only samples taken directly after virus infusion contained infectious virus. Small amounts of viral DNA, but no infectious virus, were detected in a few saliva and urine samples. Necropsies did not reveal any relevant pathological changes and virus DNA was detected mainly in the spleen. The dogs in the study did not have cancer, and thus adverse events could be more common and viral load higher in dogs with tumors which allow viral amplification.

CD4(+) T cell-mediated protection against a lethal outcome of systemic infection with vesicular stomatitis virus requires CD40 ligand expression, but not IFN-gamma or IL-4

DEFF Research Database (Denmark)

Andersen, C; Jensen, T; Nansen, A

1999-01-01

experiments using B cell- and T cell-deficient recipients revealed that no protection could be obtained in the absence of B cells, whereas treatment with virus-specific immune (IgG) serum controlled viral spreading to the central nervous system (CNS), but did not necessarily accomplish virus elimination......To investigate the mechanism(s) whereby T cells protect against a lethal outcome of systemic infection with vesicular stomatitis virus, mice with targeted defects in genes central to T cell function were tested for resistance to i.v. infection with this virus. Our results show that mice lacking...... the capacity to secrete both IFN-gamma and perforin completely resisted disease. Similar results were obtained using IL-4 knockout mice, indicating that neither cell-mediated nor T(h)2-dependent effector systems were required. In contrast, mice deficient in expression of CD40 ligand were more susceptible than...

Properties of mouse CD40: differential expression of CD40 epitopes on dendritic cells and epithelial cells

NARCIS (Netherlands)

van den Berg, T. K.; Hasbold, J.; Renardel de Lavalette, C.; Döpp, E. A.; Dijkstra, C. D.; Klaus, G. G.

1996-01-01

In this study we describe the tissue distribution of mouse CD40 using two monoclonal antibodies (mAb) against different epitopes of the molecule. In lymphoid tissues CD40 was expressed by B lymphocytes. Most B cells in typical B-cell compartments were CD40-positive, including germinal centre B

CD54/intercellular adhesion molecule 1 and major histocompatibility complex II signaling induces B cells to express interleukin 2 receptors and complements help provided through CD40 ligation

DEFF Research Database (Denmark)

Poudrier, J; Owens, T

1994-01-01

We have examined signaling roles for CD54 intercellular adhesion molecule 1 and major histocompatibility complex (MHC) II as contact ligands during T help for B cell activation. We used a T helper 1 (Th1)-dependent helper system that was previously shown to be contact as well as interleukin 2 (IL-2......) dependent to demonstrate the relative roles of CD54, MHC II, and CD40 signaling in the events leading to the induction of B cell proliferation and responsiveness to IL-2. Paraformaldehyde-fixed activated Th1-induced expression of IL-2R alpha, IL-2R beta, and B7, and upregulated MHC II and CD54 on B cells...... resulted in the upregulated expression of MHC II and of CD54 and B7, respectively, analogous to the effect of fixed activated Th1 cells. B7 expression was further enhanced by co-cross-linking CD54 and MHC II. Cross-linking of CD40 achieved comparable effects. Strikingly, cross-linking ligation of CD54...

Synthesis and Optical Properties of Thiol Functionalized CdSe/ZnS (Core/Shell Quantum Dots by Ligand Exchange

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Huaping Zhu

2014-01-01

Full Text Available The colloidal photoluminescent quantum dots (QDs of CdSe (core and CdSe/ZnS (core/shell were synthesized at different temperatures with different growth periods. Optical properties (i.e., UV/Vis spectra and photoluminescent emission spectra of the resulting QDs were investigated. The shell-protected CdSe/ZnS QDs exhibited higher photoluminescent (PL efficiency and stability than their corresponding CdSe core QDs. Ligand exchange with various thiol molecules was performed to replace the initial surface passivation ligands, that is, trioctylphosphine oxide (TOPO and trioctylphosphine (TOP, and the optical properties of the surface-modified QDs were studied. The thiol ligand molecules in this study included 1,4-benzenedimethanethiol, 1,16-hexadecanedithiol, 1,11-undecanedithiol, biphenyl-4,4′-dithiol, 11-mercapto-1-undecanol, and 1,8-octanedithiol. After the thiol functionalization, the CdSe/ZnS QDs exhibited significantly enhanced PL efficiency and storage stability. Besides surface passivation effect, such enhanced performance of thiol-functionalized QDs could be due to cross-linked assembly formation of dimer/trimer clusters, in which QDs are linked by dithiol molecules. Furthermore, effects of ligand concentration, type of ligand, and heating on the thiol stabilization of QDs were also discussed.

IL-2 and IL-15 regulate CD154 expression on activated CD4 T cells

DEFF Research Database (Denmark)

Skov, S; Bonyhadi, M; Odum, Niels

2000-01-01

The cellular and humoral immune system is critically dependent upon CD40-CD154 (CD40 ligand) interactions between CD40 expressed on B cells, macrophages, and dendritic cells, and CD154 expressed primarily on CD4 T cells. Previous studies have shown that CD154 is transiently expressed on CD4 T cells...... after T cell receptor engagement in vitro. However, we found that stimulation of PBLs with maximal CD28 costimulation, using beads coupled to Abs against CD3 and CD28, led to a very prolonged expression of CD154 on CD4 cells (>4 days) that was dependent upon autocrine IL-2 production. Previously...... activated CD4 T cells could respond to IL-2, or the related cytokine IL-15, by de novo CD154 production and expression without requiring an additional signal from CD3 and CD28. These results provide evidence that CD28 costimulation of CD4 T cells, through autocrine IL-2 production, maintains high levels...

Anti-CD40-mediated cancer immunotherapy

DEFF Research Database (Denmark)

Hassan, Sufia Butt; Sørensen, Jesper Freddie; Olsen, Barbara Nicola

2014-01-01

activation and thus enhancement of immune responses. Treatment with anti-CD40 monoclonal antibodies has been exploited in several cancer immunotherapy studies in mice and led to the development of anti-CD40 antibodies for clinical use. Here, Dacetuzumab and Lucatumumab are in the most advanced stage...... with other cancer immunotherapies, in particular interleukin (IL)-2. An in-depth analysis of this immunotherapy is provided elsewhere. In the present review, we provide an update of the most recent clinical trials with anti-CD40 antibodies. We present and discuss recent and ongoing clinical trials...... in this field, including clinical studies which combine anti-CD40 treatment with other cancer-treatments, such as Rituximab and Tremelimumab....

Systemic agonistic anti-CD40 treatment of tumor bearing mice modulates hepatic myeloid suppressive cells and causes immune-mediated liver damage

Science.gov (United States)

Medina-Echeverz, José; Ma, Chi; Duffy, Austin; Eggert, Tobias; Hawk, Nga; Kleiner, David E.; Korangy, Firouzeh; Greten, Tim F.

2015-01-01

Immune stimulatory monoclonal antibodies are currently evaluated as anti tumor agents. Although overall toxicity appears to be moderate, liver toxicities have been reported and are not completely understood. We studied the effect of systemic CD40 antibody treatment on myeloid cells in spleen and liver. Naïve and tumor-bearing mice were treated systemically with agonistic anti-CD40 antibody. Immune cell subsets in liver and spleen, serum transaminases and liver histologies were analyzed after antibody administration. Nox2−/−, Cd40−/− as well as bone marrow chimeric mice were used to study the mechanism by which agonistic anti-CD40 mediates its effects in vivo. Suppressor function of murine and human tumor-induced myeloid derived suppressive cells was studied upon CD40 ligation. Agonistic CD40 antibody caused liver damage within 24 hours after injection in two unrelated tumor models and mice strains. Using bone marrow chimeras we demonstrated that CD40 antibody-induced hepatitis in tumor-bearing mice was dependent on the presence of CD40-expressing hematopoietic cells. Agonistic CD40 ligation-dependent liver damage was induced by the generation of reactive oxygen species. Furthermore, agonistic CD40 antibody resulted in increased CD80 and CD40 positive liver CD11b+Gr-1+ immature myeloid cells. CD40 ligation on tumor-induced murine and human CD14+HLA-DRlow PBMC from cancer patients reduced their immune suppressor function. Collectively, agonistic CD40 antibody treatment activated tumor-induced, myeloid cells, caused myeloid dependent hepatotoxicity and ameliorated the suppressor function of murine and human MDSC. Collectively, our data suggests that CD40 may mature immunosuppressive myeloid cells and thereby cause liver damage in mice with an accumulation of tumor-induced hepatic MDSC. PMID:25637366

Computational Study of Magic-Size CdSe Clusters with Complementary Passivation by Carboxylic and Amine Ligands

KAUST Repository

Voznyy, Oleksandr; Mokkath, Junais Habeeb; Jain, Ankit; Sargent, Edward H.; Schwingenschlö gl, Udo

2016-01-01

The electronic and optical properties of tetrahedral CdSe magic clusters (average diameter.5 nm) protected by carboxyl and amine ligands, which correspond to previously reported experimental structures, are studied using density functional theory. We find extreme ligand packing densities, capping every single dangling bond of the inorganic core, strong dependence of the Z-type metal carboxylate binding on the amount of excess amine, and potential for improved photoluminescence upon replacing phenyl ligands with alkanes. The computed absorption spectra of the Cd35Se20 cluster agree well with experiments, resolving the 0.2 eV splitting of the first exciton peak due to spin-orbit coupling. We discuss the origin of the significant broadening of the optical spectra as due to phonons and structural variations in the ligand configurations and inorganic core apexes. © 2016 American Chemical Society.

Computational Study of Magic-Size CdSe Clusters with Complementary Passivation by Carboxylic and Amine Ligands

KAUST Repository

Voznyy, Oleksandr

2016-04-28

The electronic and optical properties of tetrahedral CdSe magic clusters (average diameter.5 nm) protected by carboxyl and amine ligands, which correspond to previously reported experimental structures, are studied using density functional theory. We find extreme ligand packing densities, capping every single dangling bond of the inorganic core, strong dependence of the Z-type metal carboxylate binding on the amount of excess amine, and potential for improved photoluminescence upon replacing phenyl ligands with alkanes. The computed absorption spectra of the Cd35Se20 cluster agree well with experiments, resolving the 0.2 eV splitting of the first exciton peak due to spin-orbit coupling. We discuss the origin of the significant broadening of the optical spectra as due to phonons and structural variations in the ligand configurations and inorganic core apexes. © 2016 American Chemical Society.

CD40 expression in Wehi-164 cell line.

Science.gov (United States)

Karimi, Mohammad Hossein; Ebadi, Padideh; Pourfathollah, Ali Akbar; Soheili, Zahra Soheila; Moazzeni, Seyed Mohammad

2010-07-01

CD40-CD154 interaction is an important process for cellular and humoral immunity regulation and can be effective in the body's defense against tumors. In the present study, we evaluated the expression of CD40 in Wehi-164 cell line. CD40 expressions on the cell surface and in the cytoplasm were assessed by flow cytometry and intracellular staining assay, respectively. Also, the mRNA expression was identified by real time-PCR. The obtained results showed the high mRNA and cytoplasmic protein expression of CD40 but no surface expression. These results suggest that the Wehi-164 cell line down regulates expression of CD40 on the surface for evasion of immune system.

Contrasting roles for TLR ligands in HIV-1 pathogenesis.

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Beda Brichacek

2010-09-01

Full Text Available The first line of a host's response to various pathogens is triggered by their engagement of cellular pattern recognition receptors (PRRs. Binding of microbial ligands to these receptors leads to the induction of a variety of cellular factors that alter intracellular and extracellular environment and interfere directly or indirectly with the life cycle of the triggering pathogen. Such changes may also affect any coinfecting microbe. Using ligands to Toll-like receptors (TLRs 5 and 9, we examined their effect on human immunodeficiency virus (HIV-1 replication in lymphoid tissue ex vivo. We found marked differences in the outcomes of such treatment. While flagellin (TLR5 agonist treatment enhanced replication of CC chemokine receptor 5 (CCR 5-tropic and CXC chemokine receptor 4 (CXCR4-tropic HIV-1, treatment with oligodeoxynucleotide (ODN M362 (TLR9 agonist suppressed both viral variants. The differential effects of these TLR ligands on HIV-1 replication correlated with changes in production of CC chemokines CCL3, CCL4, CCL5, and of CXC chemokines CXCL10, and CXCL12 in the ligand-treated HIV-1-infected tissues. The nature and/or magnitude of these changes were dependent on the ligand as well as on the HIV-1 viral strain. Moreover, the tested ligands differed in their ability to induce cellular activation as evaluated by the expression of the cluster of differentiation markers (CD 25, CD38, CD39, CD69, CD154, and human leukocyte antigen D related (HLA-DR as well as of a cell proliferation marker, Ki67, and of CCR5. No significant effect of the ligand treatment was observed on apoptosis and cell death/loss in the treated lymphoid tissue ex vivo. Our results suggest that binding of microbial ligands to TLRs is one of the mechanisms that mediate interactions between coinfected microbes and HIV-1 in human tissues. Thus, the engagement of appropriate TLRs by microbial molecules or their mimetic might become a new strategy for HIV therapy or prevention.

Functional dichotomy between NKG2D and CD28-mediated co-stimulation in human CD8+ T cells.

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Kamalakannan Rajasekaran

2010-09-01

Full Text Available Both CD28 and NKG2D can function as co-stimulatory receptors in human CD8+ T cells. However, their independent functional contributions in distinct CD8+ T cell subsets are not well understood. In this study, CD8+ T cells in human peripheral blood- and lung-derived lymphocytes were analyzed for CD28 and NKG2D expression and function. We found a higher level of CD28 expression in PBMC-derived naïve (CD45RA+CD27+ and memory (CD45RA-CD27+ CD8+ T cells (CD28Hi, while its expression was significantly lower in effector (CD45RA+CD27- CD8+ T cells (CD28Lo. Irrespective of the differences in the CD28 levels, NKG2D expression was comparable in all three CD8+ T cell subsets. CD28 and NKG2D expressions followed similar patterns in human lung-resident GILGFVFTL/HLA-A2-pentamer positive CD8+ T cells. Co-stimulation of CD28Lo effector T cells via NKG2D significantly increased IFN-γ and TNF-α levels. On the contrary, irrespective of its comparable levels, NKG2D-mediated co-stimulation failed to augment IFN-γ and TNF-α production in CD28Hi naïve/memory T cells. Additionally, CD28-mediated co-stimulation was obligatory for IL-2 generation and thereby its production was limited only to the CD28Hi naïve/memory subsets. MICA, a ligand for NKG2D was abundantly expressed in the tracheal epithelial cells, validating the use of NKG2D as the major co-stimulatory receptor by tissue-resident CD8+ effector T cells. Based on these findings, we conclude that NKG2D may provide an expanded level of co-stimulation to tissue-residing effector CD8+ T cells. Thus, incorporation of co-stimulation via NKG2D in addition to CD28 is essential to activate tumor or tissue-infiltrating effector CD8+ T cells. However, boosting a recall immune response via memory CD8+ T cells or vaccination to stimulate naïve CD8+ T cells would require CD28-mediated co-stimulation.

Diverse CdII coordination complexes derived from bromide isophthalic acid binding with auxiliary N-donor ligands

International Nuclear Information System (INIS)

Tang, Meng; Dong, Bao-Xia; Wu, Yi-Chen; Yang, Fang; Liu, Wen-Long; Teng, Yun-Lei

2016-01-01

The coordination characteristics of 4-bromoisophthalic acid (4-Br-H 2 ip) have been investigated in a series of Cd II -based frameworks. Hydrothermal reactions of Cd II salts and 4-Br-H 2 ip together with flexible or semiflexible N-donor auxiliary ligands resulted in the formation of four three-dimensional coordination complexes with diverse structures: (Cd(bix) 0.5 (bix) 0.5 (4-Br-ip)]·H 2 O) n (1), [Cd(bbi) 0.5 (bbi) 0.5 (4-Br-ip)] n (2), ([Cd(btx) 0.5 (4-Br-ip)(H 2 O)]·0.5CH 3 OH·H 2 O) n (3) and ([Cd(bbt) 0.5 (4-Br-ip)(H 2 O)]·3·5H 2 O) n (4). These compounds were characterized by elemental analyses, IR spectra, single-crystal and powder X-ray diffraction. They displayed diverse structures depending on the configuration of the 4-connected metal node, the coordination mode of the 4-Br-H 2 ip, the coordination ability and conformationally flexibility of the N-donor auxiliary. Compound 1 exhibits 3-fold interpenetrated 6 6 topology and compound 2 has a 4 12 topology. Compounds 3–4 have similar 3D pillar-layered structures based on 3,4-connected binodal net with the Schläfli symbol of (4·3 8 ). The thermal stabilities and photoluminescence properties of them were discussed in detail. - Graphical abstract: Four 3D Cd II coordination complexes on the basis of 4-bromoisophthalic acid (4-Br-H 2 ip) and two types of flexible (bbi, bbt) and semiflexible (bix, btx) N-donor ligands are prepared. They displayed diverse topology structures of 6 6 (1), 4 12 (2) and 4·3 8 (3−4), depending on the configuration of the 4-connected metal node, the coordination mode of the 4-Br-H 2 ip, the coordination ability and conformationally flexibility of the N-donor auxiliary ligand. - Highlights: • Four 3D Cd II coordination complexes based on 4-Br-H 2 ip and flexible/semiflexible N-donor ligands have been synthesized. • They displayed diverse topology structures of 6 6 for 1, 4 12 for 2 and 4·3 8 for 3–4. • The structural diversity depends on the configuration of 4-Br

Mechanism of charge transport in ligand-capped crystalline CdTe nanoparticles according to surface photovoltaic and photoacoustic results

Energy Technology Data Exchange (ETDEWEB)

Li Kuiying, E-mail: kuiyingli@ysu.edu.cn [National Laboratory of Metastable Materials Manufacture Technology and Science, Yanshan University, Hebei Str. 438, Qinhuangdao, Hebei Province 066004 (China); Zhang Hao [Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012 (China); Yang Weiyong; Wei Sailing [National Laboratory of Metastable Materials Manufacture Technology and Science, Yanshan University, Hebei Str. 438, Qinhuangdao, Hebei Province 066004 (China); Wang Dayang, E-mail: dayang@mpikg-golm.mpg.de [Max Planck Institute of Colloids and Interfaces, Potsdam 14424 (Germany)

2010-09-01

By combining surface photovoltaic and photoacoustic techniques, we probed the photogenerated charge transport channels of 3-mercaptopropionic acid (MPA)- and 2-mercaptoethylamine (MA)-capped crystalline CdTe nanoparticles on illumination with UV-near IR light. The results experimentally confirmed the presence of a CdS shell outside the CdTe core that formed through the self-assembly and decomposition of mercapto ligands during CdTe preparation. The data revealed that the CdS layer was partly responsible for the deexcitation behavior of the photogenerated carriers, which is related to the quantum tunnel effect. Experiments demonstrated that two quantum wells were located at wavelengths of 440 and 500 nm in buried interfacial space-charge regions, whereas the formation of a ligand layer obstructed charge transfer transitions of the core CdTe nanoparticles to a certain extent.

Molecular characterization of the haptoglobin.hemoglobin receptor CD163. Ligand binding properties of the scavenger receptor cysteine-rich domain region

DEFF Research Database (Denmark)

Madsen, Mette; Møller, Holger J; Nielsen, Marianne Jensby

2004-01-01

CD163 is the macrophage receptor for endocytosis of haptoglobin.hemoglobin complexes. The extracellular region consisting of nine scavenger receptor cysteine rich (SRCR) domains also circulates in plasma as a soluble protein. By ligand binding analysis of a broad spectrum of soluble CD163...... truncation variants, the amino-terminal third of the SRCR region was shown to be crucial for the binding of haptoglobin.hemoglobin complexes. By Western blotting of the CD163 variants, a panel of ten monoclonal antibodies was mapped to SRCR domains 1, 3, 4, 6, 7, and 9, respectively. Only the two antibodies...... to CD163 demonstrated that optimal ligand binding requires physiological plasma calcium concentrations, and an immediate ligand release occurs at the low calcium concentrations measured in acidifying endosomes. In conclusion, SRCR domain 3 of CD163 is an exposed domain and a critical determinant...

An age-related numerical and functional deficit in CD19(+) CD24(hi) CD38(hi) B cells is associated with an increase in systemic autoimmunity.

Science.gov (United States)

Duggal, Niharika A; Upton, Jane; Phillips, Anna C; Sapey, Elizabeth; Lord, Janet M

2013-10-01

Autoimmunity increases with aging indicative of reduced immune tolerance, but the mechanisms involved are poorly defined. In recent years, subsets of B cells with immunoregulatory properties have been identified in murine models of autoimmune disorders, and these cells downregulate immune responses via secretion of IL10. In humans, immature transitional B cells with a CD19(+) CD24(hi) CD38(hi) phenotype have been reported to regulate immune responses via IL10 production. We found the frequency and numbers of CD19(+) CD24(hi) CD38(hi) cells were reduced in the PBMC pool with age. IL10 expression and secretion following activation via either CD40, or Toll-like receptors was also impaired in CD19(+) CD24(hi) CD38(hi) B cells from healthy older donors. When investigating the mechanisms involved, we found that CD19(+) CD24(hi) CD38(hi) B-cell function was compromised by age-related effects on both T cells and B cells: specifically, CD40 ligand expression was lower in CD4 T cells from older donors following CD3 stimulation, and signalling through CD40 was impaired in CD19(+) CD24(hi) CD38(hi) B cells from elders as evidenced by reduced phosphorylation (Y705) and activation of STAT3. However, there was no age-associated change in expression of costimulatory molecules CD80 and CD86 on CD19(+) CD24(hi) CD38(hi) cells, suggesting IL10-dependent immune suppression is impaired, but contact-dependent suppressive capacity is intact with age. Finally, we found a negative correlation between CD19(+) CD24(hi) CD38(hi) B-cell IL10 production and autoantibody (Rheumatoid factor) levels in older adults. We therefore propose that an age-related decline in CD19(+) CD24(hi) CD38(hi) B cell number and function may contribute towards the increased autoimmunity and reduced immune tolerance seen with aging. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Induction of IL-12 Production in Human Peripheral Monocytes by Trypanosoma cruzi Is Mediated by Glycosylphosphatidylinositol-Anchored Mucin-Like Glycoproteins and Potentiated by IFN-γ and CD40-CD40L Interactions

Directory of Open Access Journals (Sweden)

Lúcia Cristina Jamli Abel

2014-01-01

Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, is characterized by immunopathology driven by IFN-γ secreting Th1-like T cells. T. cruzi has a thick coat of mucin-like glycoproteins covering its surface, which plays an important role in parasite invasion and host immunomodulation. It has been extensively described that T. cruzi or its products—like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins—are potent inducers of proinflammatory responses (i.e., cytokines and NO production by IFN-γ primed murine macrophages. However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells. We therefore decided to further investigate the in vitro cytokine production profile from human mononuclear cells from uninfected donors exposed to T. cruzi as well as tGPI-mucins. We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ. Our findings suggest that the polarized T1-type cytokine profile seen in T. cruzi infected patients might be a long-term effect of IL-12 production induced by lifelong exposure to T. cruzi tGPI-mucins.

A functional glycoproteomics approach identifies CD13 as a novel E-selectin ligand in breast cancer.

Science.gov (United States)

Carrascal, M A; Silva, M; Ferreira, J A; Azevedo, R; Ferreira, D; Silva, A M N; Ligeiro, D; Santos, L L; Sackstein, R; Videira, P A

2018-05-17

The glycan moieties sialyl-Lewis-X and/or -A (sLe X/A ) are the primary ligands for E-selectin, regulating subsequent tumor cell extravasation into distant organs. However, the nature of the glycoprotein scaffolds displaying these glycans in breast cancer remains unclear and constitutes the focus of the present investigation. We isolated glycoproteins that bind E-selectin from the CF1_T breast cancer cell line, derived from a patient with ductal carcinoma. Proteins were identified using bottom-up proteomics approach by nanoLC-orbitrap LTQ-MS/MS. Data were curated using bioinformatics tools to highlight clinically relevant glycoproteins, which were validated by flow cytometry, Western blot, immunohistochemistry and in-situ proximity ligation assays in clinical samples. We observed that the CF1_T cell line expressed sLe X , but not sLe A and the E-selectin reactivity was mainly on N-glycans. MS and bioinformatics analysis of the targeted glycoproteins, when narrowed down to the most clinically relevant species in breast cancer, identified CD44 glycoprotein (HCELL) and CD13 as key E-selectin ligands. Additionally, the co-expression of sLe X -CD44 and sLe X -CD13 was confirmed in clinical breast cancer tissue samples. Both CD44 and CD13 glycoforms display sLe X in breast cancer and bind E-selectin, suggesting a key role in metastasis development. Such observations provide a novel molecular rationale for developing targeted therapeutics. While HCELL expression in breast cancer has been previously reported, this is the first study indicating that CD13 functions as an E-selectin ligand in breast cancer. This observation supports previous associations of CD13 with metastasis and draws attention to this glycoprotein as an anti-cancer target. Copyright © 2018 Elsevier B.V. All rights reserved.

The CD3 gamma leucine-based receptor-sorting motif is required for efficient ligand-mediated TCR down-regulation

DEFF Research Database (Denmark)

von Essen, Marina; Menné, Charlotte; Nielsen, Bodil L

2002-01-01

. The other pathway is dependent on protein kinase C (PKC)-mediated activation of the CD3 gamma di-leucine-based receptor-sorting motif. Previous studies have failed to demonstrate a connection between ligand- and PKC-induced TCR down-regulation. Thus, although an apparent paradox, the dogma has been...... that ligand- and PKC-induced TCR down-regulations are not interrelated. By analyses of a newly developed CD3 gamma-negative T cell variant, freshly isolated and PHA-activated PBMC, and a mouse T cell line, we challenged this dogma and demonstrate in this work that PKC activation and the CD3 gamma di...

Coordination Architectures of energetic Cd (II) coordination polymers constructed by the bifunctional substituted-tetrazole-carboxylate ligands

Energy Technology Data Exchange (ETDEWEB)

Shen, Lei; Bai, Yu; Min, Yu-Ting; Jia, Tian-Tian; Wu, Qi; Wang, Jing; Geng, Fei; Cheng, Hong-Jian [Department of Chemistry & Materials Engineering, Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology, Changshu 215500 (China); Zhu, Dun-Ru [College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Yang, Jie, E-mail: jieyang@cslg.edu.cn [Department of Chemistry & Materials Engineering, Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology, Changshu 215500 (China); Yang, Gao-Wen, E-mail: ygwsx@126.com [Department of Chemistry & Materials Engineering, Jiangsu Key Laboratory of Advanced Functional Materials, Changshu Institute of Technology, Changshu 215500 (China)

2016-12-15

Three different tetrazole-carboxylate ligands, monotetrazole-carboxylate H{sub 2}tza (H{sub 2}tza=1,5-tetrazole-diacetic acid), Hpztza (Hpztza=5-(2-pyrazinyl)tetrazole-2(1-methyl)acetic acid), ditetrazole-carboxylate H{sub 2}tzpha (H{sub 2}tzpha=1,3-di(tetrazole-5-yl)benzene-N2,N2′-diacetic acid) have been chosen to react with CdCl{sub 2}·6H{sub 2}O, resulting in the formation of three new compounds [Cd{sub 2}(tza){sub 2}] (1), [Cd(pztza){sub 2}] (2) and [Cd(tzpha)(CH{sub 3}OH){sub 2}] (3). The coordinate sites of the three ligands are major influenced by the different substituted group of tetrazole ring. These compounds have been characterized by elemental analysis, IR and single crystal X-ray diffraction. Compound 1 displays a complex 3D structure; compound 2 shows a 3D network and compound 3 features a 2D layer network. Furthermore, the luminescence properties investigated at room temperature in the solid state showed excellent ligand-centered luminescence. The obvious enhancement in luminescence makes these compounds potential materials for optical use. The differential scanning calorimetry (DSC) and thermogravimetric-differential thermogravimetric (TG-DTG) analyses were applied to evaluate the thermal decomposition behavior of such compounds, showing that compounds 2 and 3 can be used as potential energetic materials. The relevant thermodynamic parameters ΔH, ΔS and ΔG were calculated as well. - Graphical abstract: H{sub 2}tza, Hpztza and H{sub 2}tzpha have been prepared. Three novel Cd (II)compounds were synthesized by reactions of CdCl{sub 2}·6H{sub 2}O, namely three dimensional [Cd{sub 2}(tza){sub 2}] (1), three dimensional [Cd(pztza){sub 2}] (2), and two dimensional [Cd(tzpha)(CH{sub 3}O){sub 2}] (3). The luminescences were investigated. Furthermore, the DSC show compounds 1 and 3 can be used as potential explosive materials.

Complete identification of E-selectin ligands on neutrophils reveals distinct functions of PSGL-1, ESL-1, and CD44.

Science.gov (United States)

Hidalgo, Andrés; Peired, Anna J; Wild, Martin; Vestweber, Dietmar; Frenette, Paul S

2007-04-01

The selectins and their ligands are required for leukocyte extravasation during inflammation. Several glycoproteins have been suggested to bind to E-selectin in vitro, but the complete identification of its physiological ligands has remained elusive. Here, we showed that E-selectin ligand-1 (ESL-1), P-selectin glycoprotein ligand-1 (PSGL-1), and CD44 encompassed all endothelial-selectin ligand activity on neutrophils by using gene- and RNA-targeted loss of function. PSGL-1 played a major role in the initial leukocyte capture, whereas ESL-1 was critical for converting initial tethers into steady slow rolling. CD44 controlled rolling velocity and mediated E-selectin-dependent redistribution of PSGL-1 and L-selectin to a major pole on slowly rolling leukocytes through p38 signaling. These results suggest distinct and dynamic contributions of these three glycoproteins in selectin-mediated neutrophil adhesion and signaling.

CD40 expression in Wehi-164 cell line

OpenAIRE

Karimi, Mohammad Hossein; Ebadi, Padideh; Pourfathollah, Ali Akbar; Soheili, Zahra Soheila; Moazzeni, Seyed Mohammad

2010-01-01

CD40-CD154 interaction is an important process for cellular and humoral immunity regulation and can be effective in the body’s defense against tumors. In the present study, we evaluated the expression of CD40 in Wehi-164 cell line. CD40 expressions on the cell surface and in the cytoplasm were assessed by flow cytometry and intracellular staining assay, respectively. Also, the mRNA expression was identified by real time-PCR. The obtained results showed the high mRNA and cytoplasmic protein ex...

Functional contribution of elevated circulating and hepatic non-classical CD14CD16 monocytes to inflammation and human liver fibrosis.

Directory of Open Access Journals (Sweden)

Henning W Zimmermann

Full Text Available BACKGROUND: Monocyte-derived macrophages critically perpetuate inflammatory responses after liver injury as a prerequisite for organ fibrosis. Experimental murine models identified an essential role for the CCR2-dependent infiltration of classical Gr1/Ly6C(+ monocytes in hepatic fibrosis. Moreover, the monocyte-related chemokine receptors CCR1 and CCR5 were recently recognized as important fibrosis modulators in mice. In humans, monocytes consist of classical CD14(+CD16(- and non-classical CD14(+CD16(+ cells. We aimed at investigating the relevance of monocyte subpopulations for human liver fibrosis, and hypothesized that 'non-classical' monocytes critically exert inflammatory as well as profibrogenic functions in patients during liver disease progression. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed circulating monocyte subsets from freshly drawn blood samples of 226 patients with chronic liver disease (CLD and 184 healthy controls by FACS analysis. Circulating monocytes were significantly expanded in CLD-patients compared to controls with a marked increase of the non-classical CD14(+CD16(+ subset that showed an activated phenotype in patients and correlated with proinflammatory cytokines and clinical progression. Correspondingly, CD14(+CD16(+ macrophages massively accumulated in fibrotic/cirrhotic livers, as evidenced by immunofluorescence and FACS. Ligands of monocyte-related chemokine receptors CCR2, CCR1 and CCR5 were expressed at higher levels in fibrotic and cirrhotic livers, while CCL3 and CCL4 were also systemically elevated in CLD-patients. Isolated monocyte/macrophage subpopulations were functionally characterized regarding cytokine/chemokine expression and interactions with primary human hepatic stellate cells (HSC in vitro. CD14(+CD16(+ monocytes released abundant proinflammatory cytokines. Furthermore, CD14(+CD16(+, but not CD14(+CD16(- monocytes could directly activate collagen-producing HSC. CONCLUSIONS/SIGNIFICANCE: Our data

Stable coordination of the inhibitory Ca2+ ion at MIDAS in integrin CD11b/CD18 by an antibody-derived ligand aspartate: Implications for integrin regulation and structure-based drug design

Science.gov (United States)

Mahalingam, Bhuvaneshwari; Ajroud, Kaouther; Alonso, Jose Luis; Anand, Saurabh; Adair, Brian; Horenstein, Alberto L; Malavasi, Fabio; Xiong, Jian-Ping; Arnaout, M. Amin

2011-01-01

A central feature of integrin interaction with physiologic ligands is the monodentate binding of a ligand carboxylate to a Mg2+ ion hexacoordinated at the metal-ion-dependent-adhesion site (MIDAS) in the integrin A-domain. This interaction stabilizes the A-domain in the high-affinity state, which is distinguished from the default low-affinity state by tertiary changes in the domain that culminate in cell adhesion. Small molecule ligand-mimetic integrin antagonists act as partial agonists, eliciting similar activating conformational changes in the A-domain, which has contributed to paradoxical adhesion and increased patient mortality in large clinical trials. As with other ligand-mimetic integrin antagonists, the function-blocking monoclonal antibody (mAb) 107 binds MIDAS of integrin CD11b/CD18 A-domain (CD11bA), but in contrast, it favors the inhibitory Ca2+ ion over Mg2+ at MIDAS. We determined the crystal structures of the Fab fragment of mAb 107 complexed to the low- and high-affinity states of CD11bA. Favored binding of Ca2+ at MIDAS is caused by the unusual symmetric bidentate ligation of a Fab-derived ligand Asp to a heptacoordinated MIDAS Ca2+. Binding of Fab 107 to CD11bA did not trigger the activating tertiary changes in the domain or in the full-length integrin. These data show that denticity of the ligand Asp/Glu can modify divalent cation selectivity at MIDAS and hence integrin function. Stabilizing the Ca2+ ion at MIDAS by bidentate ligation to a ligand Asp/Glu may provide one approach for designing pure integrin antagonists. PMID:22095715

Thermodynamic fingerprints of ligand binding to human telomeric G-quadruplexes.

Science.gov (United States)

Bončina, Matjaž; Podlipnik, Črtomir; Piantanida, Ivo; Eilmes, Julita; Teulade-Fichou, Marie-Paule; Vesnaver, Gorazd; Lah, Jurij

2015-12-02

Thermodynamic studies of ligand binding to human telomere (ht) DNA quadruplexes, as a rule, neglect the involvement of various ht-DNA conformations in the binding process. Therefore, the thermodynamic driving forces and the mechanisms of ht-DNA G-quadruplex-ligand recognition remain poorly understood. In this work we characterize thermodynamically and structurally binding of netropsin (Net), dibenzotetraaza[14]annulene derivatives (DP77, DP78), cationic porphyrin (TMPyP4) and two bisquinolinium ligands (Phen-DC3, 360A-Br) to the ht-DNA fragment (Tel22) AGGG(TTAGGG)3 using isothermal titration calorimetry, CD and fluorescence spectroscopy, gel electrophoresis and molecular modeling. By global thermodynamic analysis of experimental data we show that the driving forces characterized by contributions of specific interactions, changes in solvation and conformation differ significantly for binding of ligands with low quadruplex selectivity over duplexes (Net, DP77, DP78, TMPyP4; KTel22 ≈ KdsDNA). These contributions are in accordance with the observed structural features (changes) and suggest that upon binding Net, DP77, DP78 and TMPyP4 select hybrid-1 and/or hybrid-2 conformation while Phen-DC3 and 360A-Br induce the transition of hybrid-1 and hybrid-2 to the structure with characteristics of antiparallel or hybrid-3 type conformation. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Expression of Programmed Death-Ligand 1 by Human Colonic CD90+ Stromal Cells Differs Between Ulcerative Colitis and Crohn’s Disease and Determines Their Capacity to Suppress Th1 Cells

Directory of Open Access Journals (Sweden)

Ellen J. Beswick

2018-05-01

Full Text Available Background and AimsThe role of programmed cell death protein 1 (PD-1 and its ligands in the dysregulation of T helper immune responses observed in the inflammatory bowel disease (IBD is unclear. Recently, a novel concept emerged that CD90+ colonic (myofibroblasts (CMFs, also known as stromal cells, act as immunosuppressors, and are among the key regulators of acute and chronic inflammation. The objective of this study was to determine if the level of the PD-1 ligands is changed in the IBD inflamed colonic mucosa and to test the hypothesis that changes in IBD-CMF-mediated PD-1 ligand-linked immunosuppression is a mechanism promoting the dysregulation of Th1 cell responses.MethodsTissues and cells derived from Crohn’s disease (CD, ulcerative colitis (UC, and healthy individuals (N were studied in situ, ex vivo, and in culture.ResultsA significant increase in programmed death-ligand 1 (PD-L1 was observed in the inflamed UC colonic mucosa when compared to the non-inflamed matched tissue samples, CD, and healthy controls. UC-CMFs were among the major populations in the colonic mucosa contributing to the enhanced PD-L1 expression. In contrast, PD-L1 expression was decreased in CD-CMFs. When compared to CD-CMFs and N-CMFs, UC-CMFs demonstrated stronger suppression of IL-2, Th1 transcriptional factor Tbet, and IFN-γ expression by CD3/CD28-activated CD4+ T cells, and this process was PD-L1 dependent. Similar observations were made when differentiated Th1 cells were cocultured with UC-CMFs. In contrast, CD-CMFs showed reduced capacity to suppress Th1 cell activity and addition of recombinant PD-L1 Fc to CD-CMF:T cell cocultures partially restored the suppression of the Th1 type responses.ConclusionWe present evidence showing that increased PD-L1 expression suppresses Th1 cell activity in UC. In contrast, loss of PD-L1 expression observed in CD contributes to the persistence of the Th1 inflammatory milieu in CD. Our data suggest that

GITR ligand-costimulation activates effector and regulatory functions of CD4+ T cells

International Nuclear Information System (INIS)

Igarashi, Hanna; Cao, Yujia; Iwai, Hideyuki; Piao, Jinhua; Kamimura, Yosuke; Hashiguchi, Masaaki; Amagasa, Teruo; Azuma, Miyuki

2008-01-01

Engagement of glucocorticoid-induced TNFR-related protein (GITR) enables the costimulation of both CD25 - CD4 + effector (Teff) and CD25 + CD4 + regulatory (Treg) cells; however, the effects of GITR-costimulation on Treg function remain controversial. In this study, we examined the effects of GITR ligand (GITRL) binding on the respective functions of CD4 + T cells. GITRL-P815 transfectants efficiently augmented anti-CD3-induced proliferation and cytokine production by Teff cells. Proliferation and IL-10 production in Treg were also enhanced by GITRL transfectants when exogenous IL-2 and stronger CD3 stimulation was provided. Concomitant GITRL-costimulation of Teff and Treg converted the anergic state of Treg into a proliferating state, maintaining and augmenting their function. Thus, GITRL-costimulation augments both effector and regulatory functions of CD4 + T cells. Our results suggest that highly activated and increased ratios of Treg reverse the immune-enhancing effects of GITRL-costimulation in Teff, which may be problematic for therapeutic applications using strong GITR agonists

Despite disorganized synapse structure, Th2 cells maintain directional delivery of CD40L to antigen-presenting B cells.

Science.gov (United States)

Gardell, Jennifer L; Parker, David C

2017-01-01

Upon recognition of peptide displayed on MHC molecules, Th1 and Th2 cells form distinct immunological synapse structures. Th1 cells have a bull's eye synapse structure with TCR/ MHC-peptide interactions occurring central to a ring of adhesion molecules, while Th2 cells have a multifocal synapse with small clusters of TCR/MHC interactions throughout the area of T cell/antigen-presenting cell interaction. In this study, we investigated whether this structural difference in the immunological synapse affects delivery of T cell help. The immunological synapse is thought to ensure antigen-specific delivery of cytolytic granules and killing of target cells by NK cells and cytolytic T cells. In helper T cells, it has been proposed that the immunological synapse may direct delivery of other effector molecules including cytokines. CD40 ligand (CD40L) is a membrane-bound cytokine essential for antigen-specific T cell help for B cells in the antibody response. We incubated Th1 and Th2 cells overnight with a mixture of antigen-presenting and bystander B cells, and the delivery of CD40L to B cells and subsequent B cell responses were compared. Despite distinct immunological synapse structures, Th1 and Th2 cell do not differ in their ability to deliver CD40L and T cell help in an antigen-specific fashion, or in their susceptibility to inhibition of help by a blocking anti-CD40L antibody.

CD40L Expression Allows CD8+ T Cells to Promote Their Own Expansion and Differentiation through Dendritic Cells

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Neil Q. Tay

2017-11-01

Full Text Available CD8+ T cells play an important role in providing protective immunity against a wide range of pathogens, and a number of different factors control their activation. Although CD40L-mediated CD40 licensing of dendritic cells (DCs by CD4+ T cells is known to be necessary for the generation of a robust CD8+ T cell response, the contribution of CD8+ T cell-expressed CD40L on DC licensing is less clear. We have previously shown that CD8+ T cells are able to induce the production of IL-12 p70 by DCs in a CD40L-dependent manner, providing some evidence that CD8+ T cell-mediated activation of DCs is possible. To better understand the role of CD40L on CD8+ T cell responses, we generated and characterized CD40L-expressing CD8+ T cells both in vitro and in vivo. We found that CD40L was expressed on 30–50% of effector CD8+ T cells when stimulated and that this expression was transient. The expression of CD40L on CD8+ T cells promoted the proliferation and differentiation of both the CD40L-expressing CD8+ T cells and the bystander effector CD8+ T cells. This process occurred via a cell-extrinsic manner and was mediated by DCs. These data demonstrate the existence of a mechanism where CD8+ T cells and DCs cooperate to maximize CD8+ T cell responses.

CD40-CD40L interactions partly participate in the endothelial cel

African Journals Online (AJOL)

Jane

2011-10-17

Oct 17, 2011 ... therapies for its advantages, for instance they can carry. *Corresponding author. ... Vascular endothelial cells (ECs) represent the natural barrier between the blood ..... the kinetics of CD40L-, interleukin 1-, or tumor necrosis.

Interactions of human hemoglobin with charged ligand-functionalized iron oxide nanoparticles and effect of counterions

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Goutam, E-mail: ghoshg@yahoo.com [UGC-DAE Consortium for Scientific Research, Mumbai Centre (India); Panicker, Lata [Bhabha Atomic Research Centre, Solid State Physics Division (India)

2014-12-15

Human hemoglobin is an important metalloprotein. It has tetrameric structure with each subunit containing a ‘heme’ group which carries oxygen and carbon dioxide in blood. In this work, we have investigated the interactions of human hemoglobin (Hb) with charged ligand-functionalized iron oxide nanoparticles and the effect of counterions, in aqueous medium. Several techniques like DLS and ζ-potential measurements, UV–vis, fluorescence, and CD spectroscopy have been used to characterize the interaction. The nanoparticle size was measured to be in the range of 20–30 nm. Our results indicated the binding of Hb with both positively as well as negatively charged ligand-functionalized iron oxide nanoparticles in neutral aqueous medium which was driven by the electrostatic and the hydrophobic interactions. The electrostatic binding interaction was not seen in phosphate buffer at pH 7.4. We have also observed that the ‘heme’ groups of Hb remained unaffected on binding with charged nanoparticles, suggesting the utility of the charged ligand-functionalized nanoparticles in biomedical applications.

Extraction studies of Cd(II), Cu(II), Mn(II), Ni(II) and Zn(II) using N, N', N, N' -Bis((2-hydroxy-3,5-di-tert-butylbenzyl) (2-pyridylmethyl)) -ethylenediamine as a novel ligand

International Nuclear Information System (INIS)

Laus, R.; Anjos, A.D.; Naves, A.

2008-01-01

In the present study, the use of N,N',N,N'-bis((2-hydroxy-3,5-di-tert-butylbenzyl) (2- pyridylmethyl))-ethylenediamine (H2L) as ligand was evaluated in the liquid-liquid (water- chloroform) extraction of Cd(II), Cu(II), Mn(II), Ni(II) and Zn(II). Experiments were carried out to determine the pH for maximum extraction for each metal ion by ligand, maximum extraction capacity, extraction kinetics and extraction selectivity. The results revealed that the extraction of metal ions is dependent on the pH: maximum extraction maximum was obtained in the pH range of 4.5 - 6.0 for Cu(II) and 8.0 - 9.0 for Zn(II). Cd(II) and Mn(II) were best extracted at pH 9.0 and Ni(II) at 10.0. The ligand H2L was effective for the extraction of Cd(II), Cu(II) and Zn(II) (extraction efficient, %E equal 100%), whereas %E of 76% and 23.5% were observed for Mn(II) and Ni(II), respectively. The ligand presented high selectivity for the extraction of Cu(II) at pH 4.0. (author)

A two-dimensional layered Cd(II) coordination polymer with a three-dimensional supramolecular architecture incorporating mixed multidentate N- and O-donor ligands.

Science.gov (United States)

Huang, Qiu-Ying; Su, Ming-Yang; Meng, Xiang-Ru

2015-06-01

The combination of N-heterocyclic and multicarboxylate ligands is a good choice for the construction of metal-organic frameworks. In the title coordination polymer, poly[bis{μ2-1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole-κ(2)N(3):N(4)}(μ4-butanedioato-κ(4)O(1):O(1'):O(4):O(4'))(μ2-butanedioato-κ(2)O(1):O(4))dicadmium], [Cd(C4H4O4)(C9H8N6)]n, each Cd(II) ion exhibits an irregular octahedral CdO4N2 coordination geometry and is coordinated by four O atoms from three carboxylate groups of three succinate (butanedioate) ligands and two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligands. Cd(II) ions are connected by two kinds of crystallographically independent succinate ligands to generate a two-dimensional layered structure with bimt ligands located on each side of the layer. Adjacent layers are further connected by hydrogen bonding, leading to a three-dimensional supramolecular architecture in the solid state. Thermogravimetric analysis of the title polymer shows that it is stable up to 529 K and then loses weight from 529 to 918 K, corresponding to the decomposition of the bimt ligands and succinate groups. The polymer exhibits a strong fluorescence emission in the solid state at room temperature.

Phonon Raman spectra of colloidal CdTe nanocrystals: effect of size, non-stoichiometry and ligand exchange

Directory of Open Access Journals (Sweden)

Lokteva Irina

2011-01-01

Full Text Available Abstract Resonant Raman study reveals the noticeable effect of the ligand exchange on the nanocrystal (NC surface onto the phonon spectra of colloidal CdTe NC of different size and composition. The oleic acid ligand exchange for pyridine ones was found to change noticeably the position and width of the longitudinal optical (LO phonon mode, as well as its intensity ratio to overtones. The broad shoulder above the LO peak frequency was enhanced and sharpened after pyridine treatment, as well as with decreasing NC size. The low-frequency mode around 100 cm-1 which is commonly related with the disorder-activated acoustical phonons appears in smaller NCs but is not enhanced after pyridine treatment. Surprisingly, the feature at low-frequency shoulder of the LO peak, commonly assigned to the surface optical phonon mode, was not sensitive to ligand exchange and concomitant close packing of the NCs. An increased structural disorder on the NC surface, strain and modified electron-phonon coupling is discussed as the possible reason of the observed changes in the phonon spectrum of ligand-exchanged CdTe NCs. PACS: 63.20.-e, 78.30.-j, 78.67.-n, 78.67.Bf

Structural diversification and photocatalytic properties of three Cd(II) coordination polymers decorated with different auxiliary ligands

Energy Technology Data Exchange (ETDEWEB)

Yin, Wen-Yu; Zhuang, Guo-Yong; Huang, Zuo-Long; Cheng, Hong-Jian; Zhou, Li; Ma, Man-Hong; Wang, Hao; Tang, Xiao-Yan, E-mail: xytang@cslg.edu.cn; Ma, Yun-Sheng; Yuan, Rong-Xin, E-mail: yuanrx@cslg.edu.cn

2016-03-15

Three cadmium coordination polymers, [Cd(bismip)]{sub n} (1), {[Cd(bismip)(phen)]·H_2O}{sub n} (2) and {[Cd_2(bismip)_2(4,4′-bipy)]·2H_2O}{sub n} (3) (H{sub 2}bismip=5-(1H-benzoimidazol-2-ylsulfanylmethyl)-isophthalic acid, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine) have been prepared under solvothermal conditions. In 1, the [Cd{sub 4}(bismip){sub 3}] units are jointed by bismip ligands to afford a three-dimensional (3D) architecture. Complex 2 exhibits a 3D supramolecular framework based on the interconnection of 1D chains through hydrogen bonding interactions and π-π packing interactions. 3 is a two-fold interpenetrating 3D architecture with a (4·8{sup 2})(4{sup 2}·8{sup 4}) Schläfli symbol in which 2D layers are interlinked by 4,4′-bipy ligands. The diverse structures of compounds 1–3 indicate that the auxiliary ligands have significant effects on the final structures. The photoluminescent properties and photocatalytic properties of these coordination polymers in the solid state were also investigated. Remarkably, 3 shows the wide gap semiconductor nature and exhibit excellent photocatalytic performance. - Graphical abstract: Three cadmium coordination polymers with different architectures based on 5-(1H-benzoimidazol-2-ylsulfanylmethyl)-isophthalic acid have been prepared. Their photoluminescent properties were also investigated. - Highlights: • Three new Cd(II) Cps were synthesized based on H{sub 2}bismip. • Compounds 1 and 3 show 3D networks and 2 exhibits a 1D chain. • Compoud 3 exhibits good catalytic activity of methylene blue photodegradation.

Successful Sequential Liver and Hematopoietic Stem Cell Transplantation in a Child With CD40 Ligand Deficiency and Cryptosporidium-Induced Liver Cirrhosis.

Science.gov (United States)

Quarello, Paola; Tandoi, Francesco; Carraro, Francesca; Vassallo, Elena; Pinon, Michele; Romagnoli, Renato; David, Ezio; Dell Olio, Dominic; Salizzoni, Mauro; Fagioli, Franca; Calvo, Pier Luigi

2018-05-01

Hematopoietic stem cell transplantation (HSCT) is curative in patients with primary immunodeficiencies. However, pre-HSCT conditioning entails unacceptably high risks if the liver is compromised. The presence of a recurrent opportunistic infection affecting the biliary tree and determining liver cirrhosis with portal hypertension posed particular decisional difficulties in a 7-year-old child with X-linked CD40-ligand deficiency. We aim at adding to the scanty experience available on such rare cases, as successful management with sequential liver transplantation (LT) and HSCT has been reported in detail only in 1 young adult to date. A closely sequential strategy, with a surgical complication-free LT, followed by reduced-intensity conditioning, allowed HSCT to be performed only one month after LT, preventing Cryptosporidium parvum recolonization of the liver graft. Combined sequential LT and HSCT resolved the cirrhotic evolution and corrected the immunodeficiency so that the infection responsible for the progressive sclerosing cholangitis did not recur. Hopefully, this report of the successful resolution of a potentially fatal combination of immunodeficiency and chronic opportunistic infection with end-stage organ damage in a child will encourage others to adapt a sequential transplant approach to this highly complex pathology. However, caution is to be exercised to carefully balance the risks intrinsic to transplant surgery and immunosuppression in primary immunodeficiencies.

Differential requirements of arrestin-3 and clathrin for ligand-dependent and -independent internalization of human G protein-coupled receptor 40.

Science.gov (United States)

Qian, Jing; Wu, Chun; Chen, Xiaopan; Li, Xiangmei; Ying, Guoyuan; Jin, Lili; Ma, Qiang; Li, Guo; Shi, Ying; Zhang, Guozheng; Zhou, Naiming

2014-11-01

G protein-coupled receptor 40 (GPR40) is believed to be an attractive target to enhance insulin secretion in patients with type 2 diabetes. GPR40 has been found to couple to Gq protein, leading to the activation of phospholipase C and subsequent increases in the intracellular Ca(2+) level. However, the underlying mechanisms that regulate the internalization and desensitization of GPR40 remain to be elucidated. In the present study, a construct of GPR40 fused with enhanced green fluorescent protein (EGFP) at its C-terminus was constructed for direct imaging of the localization and internalization of GPR40 by confocal microscopy. In stably transfected HEK-293 cells, GPR40 receptors underwent rapid agonist-induced internalization and constitutive ligand-independent internalization. Our data demonstrated that the agonist-mediated internalization of GPR40 was significantly blocked by hypertonic sucrose treatment and by siRNA mediated depletion of the heavy chain of clathrin. In contrast, constitutive GPR40 internalization was not affected by hypertonic sucrose or by knock-down of clathrin expression, but it was affected by treatment with methyl-β-cyclodextrin (MβCD) and nystatin. Furthermore, our results using an arrestin-3-EGFP redistribution assay and siRNA-mediated knock-down of arrestin-3 and GRK2 expression revealed that arrestin-3 and GRK2 play an essential role in the regulation of agonist-mediated GPR40 internalization, but are not involved in the regulation of constitutive GPR40 internalization. Additionally, our observation showed that upon activation by agonist, the internalized GPR40 receptors were rapidly recycled back to the plasma membrane via Rab4/Rab5 positive endosomes, whereas the constitutively internalized GPR40 receptors were recycled back to the cell surface through Rab5 positive endosomes. Because FFA receptors exhibit a high level of homology, our observations could be applicable to other members of this family. Copyright © 2014 Elsevier Inc

Treatment efficacy and immune stimulation by AdCD40L gene therapy of spontaneous canine malignant melanoma.

Science.gov (United States)

Westberg, Sara; Sadeghi, Arian; Svensson, Emma; Segall, Thomas; Dimopoulou, Maria; Korsgren, Olle; Hemminki, Akseli; Loskog, Angelica S I; Tötterman, Thomas H; von Euler, Henrik

2013-01-01

Malignant melanoma is a serious disease in both humans and dogs, and the high metastatic potential results in poor prognosis for many patients. Its similarities with human melanoma make spontaneous canine melanoma an excellent model for comparative studies of novel therapies and tumor biology. We report a pilot study of local adenovector CD40L (AdCD40L) immunogene treatment in 19 cases of canine melanoma (14 oral, 4 cutaneous, and 1 conjunctival). Three patients were World Health Organization stage I, 2 were stage II, 10 stage III, and 4 stage IV. One to 6 intratumoral injections of AdCD40L were given every 7 days, followed by cytoreductive surgery in 9 cases and only immunotherapy in 10 cases. Tumor tissue was infiltrated with T and B lymphocytes after treatment, suggesting immune stimulation. The best overall response included 5 complete responses, 8 partial responses, and 4 stable and 2 progressive disease statuses according to the World Health Organization response criteria. Median survival was 160 days (range, 20-1141 d), with 3 dogs still alive at submission. Our results suggest that local AdCD40L therapy is safe and could have beneficial effects in dogs, supporting further treatment development. Clinical translation to human patients is in progress.

Transgenic expression of soluble human CD5 enhances experimentally-induced autoimmune and anti-tumoral immune responses.

Directory of Open Access Journals (Sweden)

Rafael Fenutría

Full Text Available CD5 is a lymphoid-specific transmembrane glycoprotein constitutively expressed on thymocytes and mature T and B1a lymphocytes. Current data support the view that CD5 is a negative regulator of antigen-specific receptor-mediated signaling in these cells, and that this would likely be achieved through interaction with CD5 ligand/s (CD5L of still undefined nature expressed on immune or accessory cells. To determine the functional consequence of loss of CD5/CD5L interaction in vivo, a new transgenic mouse line was generated (shCD5EμTg, expressing a circulating soluble form of human CD5 (shCD5 as a decoy to impair membrane-bound CD5 function. These shCD5EμTg mice showed an enhanced response to autologous antigens, as deduced from the presentation of more severe forms of experimentally inducible autoimmune disease (collagen-induced arthritis, CIA; and experimental autoimmune encephalitis, EAE, as well as an increased anti-tumoral response in non-orthotopic cancer models (B16 melanoma. This enhancement of the immune response was in agreement with the finding of significantly reduced proportions of spleen and lymph node Treg cells (CD4+CD25+FoxP3+, and of peritoneal IL-10-producing and CD5+ B cells, as well as an increased proportion of spleen NKT cells in shCD5EμTg mice. Similar changes in lymphocyte subpopulations were observed in wild-type mice following repeated administration of exogenous recombinant shCD5 protein. These data reveal the relevant role played by CD5/CD5L interactions on the homeostasis of some functionally relevant lymphocyte subpopulations and the modulation of immune responses to autologous antigens.

Two novel mixed-ligand complexes containing organosulfonate ligands.

Science.gov (United States)

Li, Mingtian; Huang, Jun; Zhou, Xuan; Fang, Hua; Ding, Liyun

2008-07-01

The structures reported herein, viz. bis(4-aminonaphthalene-1-sulfonato-kappaO)bis(4,5-diazafluoren-9-one-kappa(2)N,N')copper(II), [Cu(C(10)H(8)NO(3)S)(2)(C(11)H(6)N(2)O)(2)], (I), and poly[[[diaquacadmium(II)]-bis(mu-4-aminonaphthalene-1-sulfonato)-kappa(2)O:N;kappa(2)N:O] dihydrate], {[Cd(C(10)H(8)NO(3)S)(2)(H(2)O)(2)].2H(2)O}(n), (II), are rare examples of sulfonate-containing complexes where the anion does not fulfill a passive charge-balancing role, but takes an active part in coordination as a monodentate and/or bridging ligand. Monomeric complex (I) possesses a crystallographic inversion center at the Cu(II) atom, and the asymmetric unit contains one-half of a Cu atom, one complete 4-aminonaphthalene-1-sulfonate (ans) ligand and one 4,5-diazafluoren-9-one (DAFO) ligand. The Cu(II) atom has an elongated distorted octahedral coordination geometry formed by two O atoms from two monodentate ans ligands and by four N atoms from two DAFO molecules. Complex (II) is polymeric and its crystal structure is built up by one-dimensional chains and solvent water molecules. Here also the cation (a Cd(II) atom) lies on a crystallographic inversion center and adopts a slightly distorted octahedral geometry. Each ans anion serves as a bridging ligand linking two Cd(II) atoms into one-dimensional infinite chains along the [010] direction, with each Cd(II) center coordinated by four ans ligands via O and N atoms and by two aqua ligands. In both structures, there are significant pi-pi stacking interactions between adjacent ligands and hydrogen bonds contribute to the formation of two- and three-dimensional networks.

A series of Cd(II) complexes with π-π stacking and hydrogen bonding interactions: Structural diversities by varying the ligands

International Nuclear Information System (INIS)

Wang Xiuli; Zhang Jinxia; Liu Guocheng; Lin Hongyan

2011-01-01

Seven new Cd(II) complexes consisting of different phenanthroline derivatives and organic acid ligands, formulated as [Cd(PIP) 2 (dnba) 2 ] (1), [Cd(PIP)(ox)].H 2 O (2), [Cd(PIP)(1,4-bdc)(H 2 O)].4H 2 O (3), [Cd(3-PIP) 2 (H 2 O) 2 ].4H 2 O (4), [Cd 2 (3-PIP) 4 (4,4'-bpdc)(H 2 O) 2 ].5H 2 O (5), [Cd(3-PIP)(nip)(H 2 O)].H 2 O (6), [Cd 2 (TIP) 4 (4,4'-bpdc)(H 2 O) 2 ].3H 2 O (7) (PIP=2-phenylimidazo[4,5-f]1,10-phenanthroline, 3-PIP=2-(3-pyridyl)imidazo[4,5-f]1,10-phenanthroline, TIP=2-(2-thienyl)imidazo[4,5-f]1,10-phenanthroline, Hdnba=3,5-dinitrobenzoic acid, H 2 ox=oxalic acid, 1,4-H 2 bdc=benzene-1,4-dicarboxylic acid, 4,4'-H 2 bpdc=biphenyl-4,4'-dicarboxylic acid, H 2 nip=5-nitroisophthalic acid) have been synthesized under hydrothermal conditions. Complexes 1 and 4 possess mononuclear structures; complexes 5 and 7 are isostructural and have dinuclear structures; complexes 2 and 3 feature 1D chain structures; complex 6 contains 1D double chain, which are further extended to a 3D supramolecular structure by π-π stacking and hydrogen bonding interactions. The N-donor ligands with extended π-system and organic acid ligands play a crucial role in the formation of the final supramolecular frameworks. Moreover, thermal properties and fluorescence of 1-7 are also investigated. -- Graphical abstract: Seven new supramolecular architectures have been successfully isolated under hydrothermal conditions by reactions of different phen derivatives and Cd(II) salts together with organic carboxylate anions auxiliary ligands. Display Omitted Research highlights: → Complexes 1-7 are 0D or 1D polymeric structure, the π-π stacking and H-bonding interactions extend the complexes into 3D supramolecular network. To our knowledge, systematic study on π-π stacking and H-bonding interactions in cadmium(II) complexes are still limited. → The structural differences among the title complexes indicate the importance of N-donor chelating ligands for the creation of molecular

Synthesis, crystal structures, and luminescent properties of Cd(II) coordination polymers assembled from semi-rigid multi-dentate N-containing ligand

Energy Technology Data Exchange (ETDEWEB)

Yuan, Gang; Shao, Kui-Zhan; Chen, Lei; Liu, Xin-Xin [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China); Su, Zhong-Min, E-mail: zmsu@nenu.edu.cn [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China); Ma, Jian-Fang [Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, Jilin (China)

2012-12-15

Three new polymers, [Cd(L){sub 2}(H{sub 2}O){sub 2}]{sub n} (1), [Cd{sub 3}(L){sub 2}({mu}{sub 3}-OH){sub 2}({mu}{sub 2}-Cl){sub 2}(H{sub 2}O){sub 2}]{sub n} (2), {l_brace}[Cd{sub 2}(L){sub 2}(nic){sub 2}(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O{r_brace}{sub n} (3) (HL=5-(4-((1H-1,2,4-triazol-1-yl)methyl)phenyl)-1H-tetrazole, Hnic=nicotinic acid) have been prepared and structurally characterized. Compounds 1 and 2 display 2D monomolecular layers built by the inter-linking single helical chains and L{sup -} ligands connecting chain-like [Cd({mu}{sub 3}-OH)({mu}{sub 2}-Cl)]{sub n} secondary building units, respectively. Compound 3 is constructed from the mixed ligands and possesses a (3,4)-connected framework with (4{center_dot}8{sup 2})(4{center_dot}8{sup 2}{center_dot}10{sup 3}) topology. Moreover, the fluorescent properties of HL ligand and compounds 1-3 are also been investigated. - Graphical abstract: Three new coordination polymers based on the semi-rigid multidentate N-donor ligand have been successfully synthesized by hydrothermal reaction. Complexes 1 and 2 exhibit the 2D layers formed by inter-linking single helices and L{sup -} anions bridging 1D chain-like SBUs, respectively. Complex 3 is buit by L{sup -} and assistant nic{sup -} ligands connecting metal centers and possesses a (3,4)-connected framework with (4 Multiplication-Sign 8{sup 2})(4 Multiplication-Sign 8{sup 2} Multiplication-Sign 10{sup 3}) topology. Moreover, these complexes display fluorescent properties indicating that they may have potential applications as optical materials. Highlights: Black-Right-Pointing-Pointer Three Cd-compounds were prepared from semi-rigid HL ligand with different N-containing groups. Black-Right-Pointing-Pointer They exhibit diverse structures from 2D monomolecular layer to 3D covalent framework. Black-Right-Pointing-Pointer The HL ligands displayed various coordination modes under different reaction conditions. Black-Right-Pointing-Pointer These compounds exhibit

Effects of anti-CD40 mAb on inducing malignant B cells proliferation arrest and apoptosis and its mechanism

International Nuclear Information System (INIS)

Tang Lin; Zhuang Yumei; Zhou Zhaohua; Yu Gehua; Pan Jianzhong; Zhang Xueguang

2002-01-01

Objective: To study the expression of CD 40 molecule and the biological effects mediated by CD 40 molecules on malignant B cells. Methods: Agonistic anti-human CD 40 monoclonal antibody (clone 5C11) was added to cell culture system. Cell counting, PI staining, Annexin-V staining and flow cytometric analysis were used to study the behavior of malignant B cell lines after treatment with mAb clone 5C11. Results: 5C11 induced homotypic aggregation and proliferation arrest and mediated apoptosis in multiple myeloma cell line XG2 that expressed CD 40 strongly; 5C11 induced B lymphoma cell line Daudi homotypic aggregation and proliferation arrest and apoptosis, the apoptosis of XG2 and Daudi by CD40 activation was not mediated by TNF. Conclusion: Agonistic anti-CD 40 mAb 5C11 can inhibit the proliferation of malignant B cells by inducing them to die apoplectically

CD40 in clinical inflammation: From multiple sclerosis to atherosclerosis

NARCIS (Netherlands)

Laman, J.D.; Boer, M. de; Hart, B.A. 't

1998-01-01

The interactions of CD40 and CD40L have been known for some time to critically regulate B-cell responses with respect to proliferation, isotype switching, antibody production, and memory formation. More recent findings demonstrated that CD40 can be expressed on several other antigen-presenting cell

Impaired CD40L signaling is a cause of defective IL-12 and TNF-alpha production in Sézary syndrome: circumvention by hexameric soluble CD40L.

Science.gov (United States)

French, Lars E; Huard, Bertrand; Wysocka, Maria; Shane, Ryan; Contassot, Emmanuel; Arrighi, Jean-François; Piguet, Vincent; Calderara, Silvio; Rook, Alain H

2005-01-01

Sézary syndrome (SzS) is an advanced form of cutaneous T-cell lymphoma characterized by peripheral blood involvement, impaired cell-mediated immunity, and T-helper 1 (TH1) cytokine production. To understand the mechanism of these defects, we studied the expression and function of CD40L in peripheral blood mononuclear cells (PBMCs) of patients with SzS. We found that PBMCs of patients with SzS have a defect in interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha) production upon anti-CD3 stimulation and that tumor CD4+ T lymphocytes have a specific defect in CD40L induction after anti-CD3 ligation in vitro. This defect may explain the poor IL-12 production, because IL-12 production by anti-CD3-stimulated PBMCs was dependent on CD40L in healthy donors. The observed defect in tumor cell CD40L expression appears to be due to inappropriate T-cell signaling upon CD3 ligation, because expression of other T-cell activation antigens such as CD25, and to a lesser extent CD69, are also impaired on tumor cells. Importantly however, the inability of SzS PBMCs to appropriately produce IL-12 and TNF-alpha could be restored by recombinant hexameric CD40L. Taken together, our results demonstrate that impaired IL-12 and TNF-alpha production in SzS is associated with defective CD4+ T lymphocyte CD40L induction and indicate that CD40L may have therapeutic potential in SzS.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

International Nuclear Information System (INIS)

Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H_2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H_2O)]_n (1), [Cd(bzgluO)(2,4′-bipy)_2(H_2O)·3H_2O]_n (2), [Cd(bzgluO)(phen)·H_2O]_n (3), [Cd(bzgluO)(4,4′-bipy)(H_2O)]_n (4), [Cd(bzgluO)(bpp)(H_2O)·2H_2O]_n (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H_2bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H_2bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H_2bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid. • Each complex displays diverse structures and different supramolecular

CD4 Depletion or CD40L Blockade Results in Antigen-Specific Tolerance in a Red Blood Cell Alloimmunization Model

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Prabitha Natarajan

2017-08-01

Full Text Available Approximately 3–10% of human red blood cell (RBC transfusion recipients form alloantibodies to non-self, non-ABO blood group antigens expressed on donor RBCs, with these alloantibodies having the potential to be clinically significant in transfusion and pregnancy settings. However, the majority of transfused individuals never form detectable alloantibodies. Expanding upon observations that children initially transfused with RBCs at a young age are less likely to form alloantibodies throughout their lives, we hypothesized that “non-responders” may not only be ignorant of antigens on RBCs but instead tolerized. We investigated this question in a reductionist murine model, in which transgenic donors express the human glycophorin A (hGPA antigen in an RBC-specific manner. Although wild-type mice treated with poly IC and transfused with hGPA RBCs generated robust anti-hGPA IgG alloantibodies that led to rapid clearance of incompatible RBCs, those transfused in the absence of an adjuvant failed to become alloimmunized. Animals depleted of CD4+ cells or treated with CD40L blockade prior to initial hGPA RBC exposure, in the presence of poly IC, failed to generate detectable anti-hGPA IgG alloantibodies. These non-responders to a primary transfusion remained unable to generate anti-hGPA IgG alloantibodies upon secondary hGPA exposure and did not prematurely clear transfused hGPA RBCs even after their CD4 cells had returned or their CD40L blockade had resolved. This observed tolerance was antigen (hGPA specific, as robust IgG responses to transfused RBCs expressing a third-party antigen occurred in all studied groups. Experiments completed in an RBC alloimmunization model that allowed evaluation of antigen-specific CD4+ T-cells (HOD (hen egg lysozyme, ovalbumin, and human duffyb demonstrated that CD40L blockade prevented the expansion of ovalbumin 323-339 specific T-cells after HOD RBC transfusion and also prevented germinal center formation. Taken

Synthesis, crystal structures, and thermal and spectroscopic properties of two Cd(II) metal-organic frameworks with a versatile ligand

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Li, Jia-Ming; He, Kun-Huan; Shi, Zhong-Feng [Qinzhou Univ. (China). Guangxi Colleges and Univs. Key Lab. of Beibu Gulf Oil and Natural Gas Resource Effective Utilization; Gao, Hui-Yuan; Jiang, Yi-Min [Guangxi Normal Univ., Guilin (China). Key Lab. for the Chemistry and Molecular Engineering of Medicinal Resources

2016-11-01

Two new metal-organic frameworks, namely, [Cd(L)(H{sub 2}O)]{sub n} (1) and {[Cd_0_._5(L)(4,4"'-bipy)_0_._5][Cd_0_._5(H_2O)(4,4"'-bipy)_0_._5].H_2O}{sub n} (2), where H{sub 2}L = N-pyrazinesulfonyl-glycine and 4,4{sup '}-bipy = 4,4{sup '}-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a distorted octahedral metal coordination in a 3-connected (4, 8{sup 2}) topology, while the molecular structure of 2 has a 4-connected (4, 4) topology with two perfectly octahedrally coordinated Cd centers. The L{sup 2-} ligand serves as a N,N,O-tridentate, μ{sub 2}-pyrazine-bridging, and μ{sub 2}-carboxylate-bridging ligand in 1, and as a N,O-bidentate and μ{sub 2}-carboxylate-bridging ligand in 2. In the crystal, a 3D supramolecular architecture is formed by O-H..O hydrogen bond interactions in 1, but through O-H..O as well as π..π stacking in 2. The two compounds show intense fluorescence in the solid state at room temperature.

A robust ligand exchange approach for preparing hydrophilic, biocompatible photoluminescent quantum dots

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Wang, Sujuan; Zhou, Changhua [Key Laboratory for Special Functional Materials of the Ministry of Education, Henan University, Kaifeng 475004 (China); Yuan, Hang [Life Science Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Shen, Huaibin [Key Laboratory for Special Functional Materials of the Ministry of Education, Henan University, Kaifeng 475004 (China); Zhao, Wenxiu [Life Science Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Ma, Lan, E-mail: malan@sz.tsinghua.edu.cn [Life Science Division, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Li, Lin Song, E-mail: lsli@henu.edu.cn [Key Laboratory for Special Functional Materials of the Ministry of Education, Henan University, Kaifeng 475004 (China)

2013-08-01

Graphical abstract: - Highlights: • Aqueous CdSe/ZnS QDs were prepared using polymaleic anhydrides as capping ligand. • Effect of reaction temperature and time were systematically studied in the synthesis process. • Water-soluble QDs exhibited a good stability in physiological relevant environment. • The aqueous QDs were applied as biological probe to detect human embryonic stem cell. - Abstract: This paper describes a robust ligand exchange approach for preparing biocompatible CdSe/ZnS quantum dots (QDs) to make bioprobe for effective cell imaging. In this method, polymaleic anhydride (PMA) ligand are first used to replace original hydrophobic ligand (oleic acid) and form a protection shell with multiple hydrophilic groups to coat and protect CdSe/ZnS QDs. The as-prepared aqueous QDs exhibit small particle size, good colloidal stability in aqueous solutions with a wide range of pH, salt concentrations and under thermal treatment, which are necessary for biological applications. The use of this new class of aqueous QDs for effective cell imaging shows strong fluorescence signal to human embryonic stem cell, which demonstrate that PMA coated QDs are fully satisfied with the requirements of preparing high quality biological probe.

Human CD134 (OX40) expressed on T cells plays a key role for human herpesvirus 6B replication after allogeneic hematopoietic stem cell transplantation.

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Nagamata, Satoshi; Nagasaka, Miwako; Kawabata, Akiko; Kishimoto, Kenji; Hasegawa, Daiichiro; Kosaka, Yoshiyuki; Mori, Takeshi; Morioka, Ichiro; Nishimura, Noriyuki; Iijima, Kazumoto; Yamada, Hideto; Kawamoto, Shinichiro; Yakushijin, Kimikazu; Matsuoka, Hiroshi; Mori, Yasuko

2018-05-01

CD134 (OX40), which is a cellular receptor for human herpesvirus-6B (HHV-6B) and expresses on activated T cells, may play a key role for HHV-6B replication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, we examined the CD134 expression on T cells and HHV-6B replication after allo-HSCT, and analyzed the correlation between them. Twenty-three patients after allo-HSCT were enrolled. The percentages of CD134-positive cells within the CD4 + and CD8 + cell populations were measured by flow cytometry, and the viral copy number of HHV-6B was simultaneously quantified by real-time PCR. The correlation between CD134 and HHV-6B viral load was then statistically analyzed. HHV-6B reactivation occurred in 11 of 23 patients (47.8%). CD134 expression was seen on T cells and was coincident with the time of peak viral load. The percentage of CD134-positive cells decreased significantly when HHV-6B DNA disappeared (p = .005 in CD4 + T cells, p = .02 in CD8 + T cells). In the 4 patients who underwent umbilical cord blood transplantation (UCBT), the viral load varied with the percentage of CD134-positive cells. In the comparison between the HHV-6B reactivation group and non-reactivation group, maximum percentages of CD134-positive cells among CD4 + T cells in reactivation group were significantly higher than those in non-reactivation group (p = .04). This is the first study to show that a correlation of CD134 expression on T cells with HHV-6B replication after allo-HSCT, especially in UCBT. The results possibly indicate that CD134 on T cells plays a key role for HHV-6B replication after allo-HSCT. Copyright © 2018 Elsevier B.V. All rights reserved.

Loss of CD34 expression in aging human choriocapillaris endothelial cells.

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Elliott H Sohn

Full Text Available Structural and gene expression changes in the microvasculature of the human choroid occur during normal aging and age-related macular degeneration (AMD. In this study, we sought to determine the impact of aging and AMD on expression of the endothelial cell glycoprotein CD34. Sections from 58 human donor eyes were categorized as either young (under age 40, age-matched controls (> age 60 without AMD, or AMD affected (>age 60 with early AMD, geographic atrophy, or choroidal neovascularization. Dual labeling of sections with Ulex europaeus agglutinin-I lectin (UEA-I and CD34 antibodies was performed, and the percentage of capillaries labeled with UEA-I but negative for anti-CD34 was determined. In addition, published databases of mouse and human retinal pigment epithelium-choroid were evaluated and CD34 expression compared between young and old eyes. Immunohistochemical studies revealed that while CD34 and UEA-I were colocalized in young eyes, there was variable loss of CD34 immunoreactivity in older donor eyes. While differences between normal aging and AMD were not significant, the percentage of CD34 negative capillaries in old eyes, compared to young eyes, was highly significant (p = 3.8×10(-6. Endothelial cells in neovascular membranes were invariably CD34 positive. Published databases show either a significant decrease in Cd34 (mouse or a trend toward decreased CD34 (human in aging. These findings suggest that UEA-I and endogenous alkaline phosphatase activity are more consistent markers of aging endothelial cells in the choroid, and suggest a possible mechanism for the increased inflammatory milieu in the aging choroid.

Flow Cytometry Assessment of In Vitro Generated CD138+ Human Plasma Cells

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Rayelle Itoua Maïga

2014-01-01

Full Text Available The in vitro CD40-CD154 interaction promotes human B lymphocytes differentiation into plasma cells. Currently, CD138 is the hallmark marker enabling the detection of human plasma cells, both in vitro and in vivo; its presence can be monitored by flow cytometry using a specific antibody. We have developed a culture system allowing for the differentiation of memory B lymphocytes. In order to detect the newly formed plasma cells, we have compared their staining using five anti-CD138 monoclonal antibodies (mAbs. As a reference, we also tested human cell lines, peripheral blood mononuclear cells, and bone marrow samples. The five anti-CD138 mAbs stained RPMI-8226 cells (>98% with variable stain index (SI. The highest SI was obtained with B-A38 mAb while the lowest SI was obtained with DL-101 and 1D4 mAbs. However, the anti-CD138 mAbs were not showing equivalent CD138+ cells frequencies within the generated plasma cells. B-A38, B-B4, and MI-15 were similar (15–25% while DL-101 mAb stained a higher proportion of CD138-positive cells (38–42%. DL-101 and B-A38 mAbs stained similar populations in bone marrow samples but differed in their capacity to bind to CD138high and CD138lo cell lines. In conclusion, such cellular fluctuations suggest heterogeneity in human plasma cell populations and/or in CD138 molecules.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

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Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua, E-mail: songhuihua@mail.hebtu.edu.cn; Yu, Hai-Tao, E-mail: haitaoyu@mail.hebtu.edu.cn

2016-01-15

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H{sub 2}bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2′-bipy)(H{sub 2}O)]{sub n} (1), [Cd(bzgluO)(2,4′-bipy){sub 2}(H{sub 2}O)·3H{sub 2}O]{sub n} (2), [Cd(bzgluO)(phen)·H{sub 2}O]{sub n} (3), [Cd(bzgluO)(4,4′-bipy)(H{sub 2}O)]{sub n} (4), [Cd(bzgluO)(bpp)(H{sub 2}O)·2H{sub 2}O]{sub n} (5) were synthesized (2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, phen=1,10-phenanthroline, 4,4′-bipy=4,4′-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1–2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π–π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π–π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H{sub 2}bzgluO. Luminescent properties of 1–5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated. - Graphical abstract: Five new Cd(II) metal coordination compounds with H{sub 2}bzgluO and different N-donor ligands were synthesized and characterized. Compounds 1, 2 and 3 present 1D structures, compounds 4 and 5 display 2D networks. Results indicate that auxiliary ligands and coordination modes of H{sub 2}bzgluO play an important role in governing the formation of final frameworks, and the hydrogen-bonding and π–π stacking interactions contribute the formation of the diverse supramolecular architectures. Furthermore, the different crystal structures influence the emission spectra significantly. - Highlights: • It is rarely reported that complexes prepared with N-benzoyl-L-glutamic acid

Study of association of CD40-CD154 gene polymorphisms with disease susceptibility and cardiovascular risk in Spanish rheumatoid arthritis patients.

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Mercedes García-Bermúdez

Full Text Available Rheumatoid arthritis (RA is a chronic inflammatory disease associated with increased cardiovascular (CV mortality. Since CD40-CD154 binding has direct consequences on inflammation process initiation, we aimed to replicate previous findings related to disease susceptibility in Spanish RA population. Furthermore, as the major complication in RA disease patients is the development of CV events due to accelerated atherosclerosis, and elevated levels of CD40L/CD154 are present in patients with acute myocardial infarction, we assessed the potential association of CD40 and CD154/CD40L gene variants with CV risk in Spanish RA patients.One thousand five hundred and seventy-five patients fulfilling the 1987 ACR classification criteria for RA and 1600 matched controls were genotyped for the CD40 rs1883832, rs4810485 and rs1535045 and CD154 rs3092952 and rs3092920 gene polymorphisms, using predesigned TaqMan single nucleotide polymorphism genotyping assays. Afterwards, we investigated the influence of CD40-CD154 gene variants in the development of CV events. Also, in a subgroup of 273 patients without history of CV events, we assessed the influence of these polymorphisms in the risk of subclinical atherosclerosis determined by carotid ultrasonography.Nominally significant differences in the allele frequencies for the rs1883832 CD40 gene polymorphism between RA patients and controls were found (p=0.038. Although we did not observe a significant association of CD40-CD154 gene variants with the development of CV events, an ANCOVA model adjusted for sex, age at the time of the ultrasonography assessment, follow-up time, traditional CV risk factors and anti-cyclic citrullinated peptide antibodies disclosed a significant association (p=0.0047 between CD40 rs1535045 polymorphism and carotid intima media thickness, a surrogate marker of atherosclerosis.Data from our pilot study indicate a potential association of rs1883832 CD40 gene polymorphism with susceptibility

Anti-proliferative effects of T cells expressing a ligand-based chimeric antigen receptor against CD116 on CD34+ cells of juvenile myelomonocytic leukemia

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Yozo Nakazawa

2016-03-01

Full Text Available Abstract Background Juvenile myelomonocytic leukemia (JMML is a fatal, myelodysplastic/myeloproliferative neoplasm of early childhood. Patients with JMML have mutually exclusive genetic abnormalities in granulocyte-macrophage colony-stimulating factor (GM-CSF receptor (GMR, CD116 signaling pathway. Allogeneic hematopoietic stem cell transplantation is currently the only curative treatment option for JMML; however, disease recurrence is a major cause of treatment failure. We investigated adoptive immunotherapy using GMR-targeted chimeric antigen receptor (CAR for JMML. Methods We constructed a novel CAR capable of binding to GMR via its ligand, GM-CSF, and generated piggyBac transposon-based GMR CAR-modified T cells from three healthy donors and two patients with JMML. We further evaluated the anti-proliferative potential of GMR CAR T cells on leukemic CD34+ cells from six patients with JMML (two NRAS mutations, three PTPN11 mutations, and one monosomy 7, and normal CD34+ cells. Results GMR CAR T cells from healthy donors suppressed the cytokine-dependent growth of MO7e cells, but not the growth of K562 and Daudi cells. Co-culture of healthy GMR CAR T cells with CD34+ cells of five patients with JMML at effector to target ratios of 1:1 and 1:4 for 2 days significantly decreased total colony growth, regardless of genetic abnormality. Furthermore, GMR CAR T cells from a non-transplanted patient and a transplanted patient inhibited the proliferation of respective JMML CD34+ cells at onset to a degree comparable to healthy GMR CAR T cells. Seven-day co-culture of GMR CAR T cells resulted in a marked suppression of JMML CD34+ cell proliferation, particularly CD34+CD38− cell proliferation stimulated with stem cell factor and thrombopoietin on AGM-S3 cells. Meanwhile, GMR CAR T cells exerted no effects on normal CD34+ cell colony growth. Conclusions Ligand-based GMR CAR T cells may have anti-proliferative effects on stem and progenitor cells in JMML.

Glycosaminoglycans Regulate CXCR3 Ligands at Distinct Levels: Protection against Processing by Dipeptidyl Peptidase IV/CD26 and Interference with Receptor Signaling

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Mieke Metzemaekers

2017-07-01

Full Text Available CXC chemokine ligand (CXCL9, CXCL10 and CXCL11 direct chemotaxis of mainly T cells and NK cells through activation of their common CXC chemokine receptor (CXCR3. They are inactivated upon NH2-terminal cleavage by dipeptidyl peptidase IV/CD26. In the present study, we found that different glycosaminoglycans (GAGs protect the CXCR3 ligands against proteolytic processing by CD26 without directly affecting the enzymatic activity of CD26. In addition, GAGs were shown to interfere with chemokine-induced CXCR3 signaling. The observation that heparan sulfate did not, and heparin only moderately, altered CXCL10-induced T cell chemotaxis in vitro may be explained by a combination of protection against proteolytic inactivation and altered receptor interaction as observed in calcium assays. No effect of CD26 inhibition was found on CXCL10-induced chemotaxis in vitro. However, treatment of mice with the CD26 inhibitor sitagliptin resulted in an enhanced CXCL10-induced lymphocyte influx into the joint. This study reveals a dual role for GAGs in modulating the biological activity of CXCR3 ligands. GAGs protect the chemokines from proteolytic cleavage but also directly interfere with chemokine–CXCR3 signaling. These data support the hypothesis that both GAGs and CD26 affect the in vivo chemokine function.

Improving polymer/nanocrystal hybrid solar cell performance via tuning ligand orientation at CdSe quantum dot surface.

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Fu, Weifei; Wang, Ling; Zhang, Yanfang; Ma, Ruisong; Zuo, Lijian; Mai, Jiangquan; Lau, Tsz-Ki; Du, Shixuan; Lu, Xinhui; Shi, Minmin; Li, Hanying; Chen, Hongzheng

2014-11-12

Achieving superior solar cell performance based on the colloidal nanocrystals remains challenging due to their complex surface composition. Much attention has been devoted to the development of effective surface modification strategies to enhance electronic coupling between the nanocrystals to promote charge carrier transport. Herein, we aim to attach benzenedithiol ligands onto the surface of CdSe nanocrystals in the "face-on" geometry to minimize the nanocrystal-nanocrystal or polymer-nanocrystal distance. Furthermore, the "electroactive" π-orbitals of the benzenedithiol are expected to further enhance the electronic coupling, which facilitates charge carrier dissociation and transport. The electron mobility of CdSe QD films was improved 20 times by tuning the ligand orientation, and high performance poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):CdSe nanocrystal hybrid solar cells were also achieved, showing a highest power conversion efficiency of 4.18%. This research could open up a new pathway to improve further the performance of colloidal nanocrystal based solar cells.

Elusive Role of the CD94/NKG2C NK Cell Receptor in the Response to Cytomegalovirus: Novel Experimental Observations in a Reporter Cell System

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Aldi Pupuleku

2017-10-01

Full Text Available Human cytomegalovirus (HCMV infection promotes the differentiation and persistent expansion of a mature NK cell subset, which displays high surface levels of the activating CD94/NKG2C NK cell receptor, together with additional distinctive phenotypic and functional features. The mechanisms underlying the development of adaptive NK cells remain uncertain but some observations support the involvement of a cognate interaction of CD94/NKG2C with ligand(s displayed by HCMV-infected cells. To approach this issue, the heterodimer and its adaptor (DAP12 were expressed in the human Jurkat leukemia T cell line; signaling was detected by transfection of a reporter plasmid encoding for Luciferase (Luc under NFAT/AP1-dependent control. Engagement of the receptor by solid-phase bound CD94- or NKG2C-specific monoclonal antibodies (mAbs triggered Luc expression. Moreover, reporter activation was detectable upon interaction with HLA-E+ 721.221 (.221-AEH cells, as well as with 721.221 cells incubated with synthetic peptides, which stabilized surface expression of endogenous HLA-E; the response was specifically antagonized by soluble NKG2C- and HLA-E-specific mAbs. By contrast, activation of Jurkat-NKG2C+ was undetectable upon interaction with Human Fetal Foreskin Fibroblasts (HFFF infected with HCMV laboratory strains (i.e., AD169, Towne, regardless of their differential ability to preserve surface HLA-E expression. On the other hand, infection with two clinical isolates or with the endotheliotropic TB40/E strain triggered Jurkat-NKG2C+ activation; yet, this response was not inhibited by blocking mAbs and was independent of CD94/NKG2C expression. The results are discussed in the framework of previous observations supporting the hypothetical existence of specific ligand(s for CD94/NKG2C in HCMV-infected cells.

Assessment of serum levels of soluble CD40L in Egyptian children and adolescents with type 1 diabetes mellitus: Relationship to microalbuminuria and glycemic control

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Kotb Abbass Metwalley

2013-01-01

Full Text Available Context: Soluble CD40 ligand (sCD40L is known to be elevated in different clinical situations including hypercholesterolemia, acute coronary syndromes, and type 2 diabetes mellitus (T2DM, Data about the relationship between type 1 diabetes mellitus (T1DM and sCD40L is limited. In addition, the potential role ofsCD40Lin the pathogenesis of vascular complications in children and adolescents with T1DM is to be clarified. Hence, the study aimed at assessment of sCD40L levels in children and adolescents with T1DM and correlation of these levels with glycemic control and microalbuminuria. Settings and Design: Cross-sectional controlled study. Materials and Methods: The study was performed in the Pediatric Endocrinology and Diabetes Unit, Assuit University Children Hospital, Assiut, Egypt. It included 70 children and adolescents with T1DM (mean age 14. 76 ± 2.21 years. Cases were further subdivided into 43 cases with normoalbuminuria and 27 cases with microalbuminuria according to presence or absence or microalbuminuria in fresh urine samples. Twentyfive healthy subjects, age- and sex-matched were included as control group (mean age = 13.62 ± 2.11 years. Studied cases were subjected to medical history, clinical examination, and laboratory assessment of fasting blood glucose (FBG, lipid profile, glycosylated hemoglobin (HbA1c, and sCD40L were performed. Results: Mean HbA1c and sCD40L were significantly higher in diabetic children (n = 70 compared to control (n = 25 (P < 0.001 for each. Mean HbA1c and sCD40L levels were significantly higher in microalbuminuric cases (n = 27 compared to normoalbuminuric cases (n = 43 (P < 0.05 and <0.01, respectively.We also observed a significant positive correlation between sCD40L levels and the age, diabetes duration, HbA1c, and urinary albumin creatinine ratio. Conclusions: The high serum sCD40L levels in children and adolescents with T1DM particularly in those with microalbminuria and its positive correlation with

Reprogramming tumor-infiltrating dendritic cells for CD103+CD8+ mucosal T cell differentiation and breast cancer rejection

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Wu, Te-Chia; Xu, Kangling; Banchereau, Romain; Marches, Florentina; Yu, Chun I; Martinek, Jan; Anguiano, Esperanza; Pedroza-Gonzalez, Alexander; Snipes, G. Jackson; O’Shaughnessy, Joyce; Nishimura, Stephen; Liu, Yong-Jun; Pascual, Virginia; Banchereau, Jacques; Oh, Sangkon; Palucka, Karolina

2014-01-01

Our studies showed that tumor-infiltrating dendritic cells (DC) in breast cancer drive inflammatory T helper 2 (iTh2) cells and protumor inflammation. Here we show that intratumoral delivery of the β-glucan curdlan, a ligand of dectin-1, blocks the generation of iTh2 cells, and prevents breast cancer progression in vivo. Curdlan reprograms tumor-infiltrating DC via the ligation of dectin-1, enabling the DC to become resistant to cancer-derived thymic stromal lymphopoietin (TSLP), to produce IL12p70, and to favor the generation of T helper 1 (Th1) cells. DC activated via dectin-1, but not those activated with TLR-7/8 ligand or poly IC, induce CD8+ T cells to express CD103 (αE integrin), a ligand for cancer cells E-cadherin. Generation of these mucosal CD8+ T cells is regulated by DC-derived integrin αvβ8 and TGF-β activation in a dectin-1-dependent fashion. These CD103+CD8+ mucosal T cells accumulate in the tumors thereby increasing cancer necrosis and inhibiting cancer progression in vivo in a humanized mouse model of breast cancer. Importantly, CD103+CD8+ mucosal T cells elicited by reprogrammed DC can reject established cancer. Thus, reprogramming tumor-infiltrating DC represents a new strategy for cancer rejection. PMID:24795361

Solution characterization of the extracellular region of CD147 and its interaction with its enzyme ligand cyclophilin-A

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Schlegel, Jennifer; Redzic, Jasmina S.; Porter, Christopher; Yurchenko, Vyacheslav; Bukrinsky, Michael; Labeikovsky, Wladimir; Armstrong, Geoffrey S.; Zhang, Fengli; Isern, Nancy G.; Degregori, James; Hodges, Robert; Eisenmesser, Elan Z.

2009-08-21

The CD147 receptor plays an integral role in numerous diseases by stimulating the expression of several protein families and serving as the receptor for extracellular cyclophilins, however, neither CD147 nor its interactions with its cyclophilin ligands have been well characterized in solution. CD147 is a unique protein in that it can function both at the cell membrane and after being released from cells where it continues to retain activity. Thus, the CD147 receptor functions through at least two mechanisms that include both cyclophilin-independent and cyclophilin-dependent modes of action. In regard to CD147 cyclophilin-independent activity, CD147 homophilic interactions are thought to underlie its activity. In regard to CD147 cyclophilin-dependent activity, cyclophilin/CD147 interactions may represent a novel means of signaling since cyclophilins are also peptidyl-prolyl isomerases.

Scaffold protein JLP mediates TCR-initiated CD4+T cell activation and CD154 expression.

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Yan, Qi; Yang, Cheng; Fu, Qiang; Chen, Zhaowei; Liu, Shan; Fu, Dou; Rahman, Rahmat N; Nakazato, Ryota; Yoshioka, Katsuji; Kung, Sam K P; Ding, Guohua; Wang, Huiming

2017-07-01

CD4 + T-cell activation and its subsequent induction of CD154 (CD40 ligand, CD40L) expression are pivotal in shaping both the humoral and cellular immune responses. Scaffold protein JLP regulates signal transduction pathways and molecular trafficking inside cells, thus represents a critical component in maintaining cellular functions. Its role in regulating CD4 + T-cell activation and CD154 expression, however, is unclear. Here, we demonstrated expression of JLP in mouse tissues of lymph nodes, thymus, spleen, and also CD4 + T cells. Using CD4+ T cells from jlp-deficient and jlp-wild-type mice, we demonstrated that JLP-deficiency impaired T-cell proliferation, IL-2 production, and CD154 induction upon TCR stimulations, but had no impacts on the expression of other surface molecules such as CD25, CD69, and TCR. These observed impaired T-cell functions in the jlp-/- CD4 + T cells were associated with defective NF-AT activation and Ca 2 + influx, but not the MAPK, NF-κB, as well as AP-1 signaling pathways. Our findings indicated that, for the first time, JLP plays a critical role in regulating CD4 + T cells response to TCR stimulation partly by mediating the activation of TCR-initiated Ca 2+ /NF-AT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differential requirements of CD4(+) T-cell signals for effector cytotoxic T-lymphocyte (CTL) priming and functional memory CTL development at higher CD8(+) T-cell precursor frequency.

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Umeshappa, Channakeshava S; Nanjundappa, Roopa H; Xie, Yufeng; Freywald, Andrew; Xu, Qingyong; Xiang, Jim

2013-04-01

Increased CD8(+) T-cell precursor frequency (PF) precludes the requirement of CD4(+) helper T (Th) cells for primary CD8(+) cytotoxic T-lymphocyte (CTL) responses. However, the key questions of whether unhelped CTLs generated at higher PF are functional effectors, and whether unhelped CTLs can differentiate into functional memory cells at higher PF are unclear. In this study, ovalbumin (OVA) -pulsed dendritic cells (DC(OVA)) derived from C57BL/6, CD40 knockout (CD40(-/-)) or CD40 ligand knockout (CD40L(-/-)) mice were used to immunize C57BL/6, Ia(b-/-), CD40(-/-) or CD40L(-/-) mice, whose PF was previously increased with transfer of 1 × 10(6) CD8(+) T cells derived from OVA-specific T-cell receptor (TCR) transgenic OTI, OTI(CD40(-/-)) or OTI(CD40L(-/-)) mice. All the immunized mice were then assessed for effector and memory CTL responses. Following DC immunization, relatively comparable CTL priming occurred without CD4(+) T-cell help and Th-provided CD40/CD40L signalling. In addition, the unhelped CTLs were functional effectors capable of inducing therapeutic immunity against established OVA-expressing tumours. In contrast, the functional memory development of CTLs was severely impaired in the absence of CD4(+) T-cell help and CD40/CD40L signalling. Finally, unhelped memory CTLs failed to protect mice against lethal tumour challenge. Taken together, these results demonstrate that CD4(+) T-cell help at higher PF, is not required for effector CTL priming, but is required for functional memory CTL development against cancer. Our data may impact the development of novel preventive and therapeutic approaches in cancer patients with compromised CD4(+) T-cell functions. © 2012 Blackwell Publishing Ltd.

Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

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Anne Marie Kay Kovach

2016-10-01

Full Text Available Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF antibody and ligand cluster of differentiation 80 (CD80 for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA. The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTMNPO CRL-2836 at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF. Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum

[Regulatory B cells activated by CpG-ODN combined with anti-CD40 monoclonal antibody inhibit CD4(+)T cell proliferation].

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Wang, Keng; Tao, Lei; Su, Jianbing; Zhang, Yueyang; Zou, Binhua; Wang, Yiyuan; Li, Xiaojuan

2016-09-01

Objective To observe the immunosuppressive function of regulatory B cells (Bregs) in vitro after activated by CpG oligodeoxynucleotide (CpG-ODN) and anti-CD40 mAb. Methods Mice splenic CD5(+)CD1d(high)B cells and CD5(-)CD1d(low)B cells were sorted by flow cytometry. These B cells were first stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours, and then co-cultured with purified CD4(+)T cells. The interleukin 10 (IL-10) expression in the activated Bregs and other B cell subset, as well as the proliferation and interferon γ (IFN-γ) expression in the CD4(+) T cells activated by anti-CD3 mAb plus anti-CD28 mAb were determined by flow cytometry. Results CD5(+)CD1d(high) B cells activated by CpG-ODN plus anti-CD40 mAb blocked the up-regulated CD4(+)T proliferation and significantly reduced the IFN-γ level. At the same time, activated CD5(-)CD1d(low)B cells showed no inhibitory effect on CD4(+)T cells. Further study revealed that IL-10 expression in the CD5(+)CD1d(high) B cells were much higher than that in the CD5(-)CD1d(low)B cells after stimulated with CpG-ODN combined with anti-CD40 mAb for 24 hours. Conclusion CD5(+)CD1d(high) B cells activated by CpG-ODN combined with anti-CD40 mAb have immune inhibitory effects on CD4(+)T cell activation in vitro , which possibly due to IL-10 secretion.

Expression of Siglec-11 by human and chimpanzee ovarian stromal cells, with uniquely human ligands: implications for human ovarian physiology and pathology

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Wang, Xiaoxia; Chow, Renee; Deng, Liwen; Anderson, Dan; Weidner, Noel; Godwin, Andrew K; Bewtra, Chanda; Zlotnik, Albert; Bui, Jack; Varki, Ajit; Varki, Nissi

2011-01-01

Siglecs (Sialic acid-binding Immunoglobulin Superfamily Lectins) are cell surface signaling receptors of the I-type lectin group that recognize sialic acid-bearing glycans. CD33-related-Siglecs are a subset with expression primarily in cells of hematopoietic origin and functional relevance to immune reactions. Earlier we reported a human-specific gene conversion event that markedly changed the coding region for the extracellular domain of Siglec-11, associated with human-specific expression in microglia (Hayakawa T, Angata T, Lewis AL, Mikkelsen TS, Varki NM, Varki A. 2005. A human-specific gene in microglia. Science. 309:1693). Analyzing human gene microarrays to define new patterns of expression, we observed high levels of SIGLEC11 transcript in the ovary and adrenal cortex. Thus, we examined human and chimpanzee tissues using a well-characterized anti-Siglec-11 mouse monoclonal antibody. Although adrenal expression was variable and confined to infiltrating macrophages in capillaries, ovarian expression of Siglec-11 in both humans and chimpanzees was on fibroblasts, the first example of Siglec expression on mesenchyme-derived stromal cells. Cytokines from such ovarian stromal fibroblasts play important roles in follicle development and ovulation. Stable transfection of SIGLEC11 into a primary human ovarian stromal fibroblast cell line altered the secretion of growth-regulated oncogene α, interleukin (IL)-10, IL-7, transforming growth factor β1 and tumor necrosis factor-α, cytokines involved in ovarian physiology. Probing for Siglec-11 ligands revealed distinct and strong mast cell expression in human ovaries, contrasting to diffuse stromal ligands in chimpanzee ovaries. Interestingly, there was a trend of increased Siglec-11 expression in post-menopausal ovaries compared with pre-menopausal ones. Siglec-11 expression was also found on human ovarian stromal tumors and in polycystic ovarian syndrome, a human-specific disease. These results indicate potential

Tumor-Targeted Human T Cells Expressing CD28-Based Chimeric Antigen Receptors Circumvent CTLA-4 Inhibition.

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Maud Condomines

Full Text Available Adoptive T cell therapy represents a promising treatment for cancer. Human T cells engineered to express a chimeric antigen receptor (CAR recognize and kill tumor cells in a MHC-unrestricted manner and persist in vivo when the CAR includes a CD28 costimulatory domain. However, the intensity of the CAR-mediated CD28 activation signal and its regulation by the CTLA-4 checkpoint are unknown. We investigated whether T cells expressing an anti-CD19, CD3 zeta and CD28-based CAR (19-28z displayed the same proliferation and anti-tumor abilities than T cells expressing a CD3 zeta-based CAR (19z1 costimulated through the CD80/CD28, ligand/receptor pathway. Repeated in vitro antigen-specific stimulations indicated that 19-28z+ T cells secreted higher levels of Th1 cytokines and showed enhanced proliferation compared to those of 19z1+ or 19z1-CD80+ T cells. In an aggressive pre-B cell leukemia model, mice treated with 19-28z+ T cells had 10-fold reduced tumor progression compared to those treated with 19z1+ or 19z1-CD80+ T cells. shRNA-mediated CTLA-4 down-regulation in 19z1-CD80+ T cells significantly increased their in vivo expansion and anti-tumor properties, but had no effect in 19-28z+ T cells. Our results establish that CTLA-4 down-regulation may benefit human adoptive T cell therapy and demonstrate that CAR design can elude negative checkpoints to better sustain T cell function.

Dendritic cell based PSMA immunotherapy for prostate cancer using a CD40-targeted adenovirus vector.

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Briana Jill Williams

Full Text Available Human prostate tumor vaccine and gene therapy trials using ex vivo methods to prime dendritic cells (DCs with prostate specific membrane antigen (PSMA have been somewhat successful, but to date the lengthy ex vivo manipulation of DCs has limited the widespread clinical utility of this approach. Our goal was to improve upon cancer vaccination with tumor antigens by delivering PSMA via a CD40-targeted adenovirus vector directly to DCs as an efficient means for activation and antigen presentation to T-cells. To test this approach, we developed a mouse model of prostate cancer by generating clonal derivatives of the mouse RM-1 prostate cancer cell line expressing human PSMA (RM-1-PSMA cells. To maximize antigen presentation in target cells, both MHC class I and TAP protein expression was induced in RM-1 cells by transduction with an Ad vector expressing interferon-gamma (Ad5-IFNγ. Administering DCs infected ex vivo with CD40-targeted Ad5-huPSMA, as well as direct intraperitoneal injection of the vector, resulted in high levels of tumor-specific CTL responses against RM-1-PSMA cells pretreated with Ad5-IFNγ as target cells. CD40 targeting significantly improved the therapeutic antitumor efficacy of Ad5-huPSMA encoding PSMA when combined with Ad5-IFNγ in the RM-1-PSMA model. These results suggest that a CD-targeted adenovirus delivering PSMA may be effective clinically for prostate cancer immunotherapy.

Distinct and overlapping effector functions of expanded human CD4+, CD8α+ and CD4-CD8α- invariant natural killer T cells.

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Vincent O'Reilly

Full Text Available CD1d-restricted invariant natural killer T (iNKT cells have diverse immune stimulatory/regulatory activities through their ability to release cytokines and to kill or transactivate other cells. Activation of iNKT cells can protect against multiple diseases in mice but clinical trials in humans have had limited impact. Clinical studies to date have targeted polyclonal mixtures of iNKT cells and we proposed that their subset compositions will influence therapeutic outcomes. We sorted and expanded iNKT cells from healthy donors and compared the phenotypes, cytotoxic activities and cytokine profiles of the CD4(+, CD8α(+ and CD4(-CD8α(- double-negative (DN subsets. CD4(+ iNKT cells expanded more readily than CD8α(+ and DN iNKT cells upon mitogen stimulation. CD8α(+ and DN iNKT cells most frequently expressed CD56, CD161 and NKG2D and most potently killed CD1d(+ cell lines and primary leukemia cells. All iNKT subsets released Th1 (IFN-γ and TNF-α and Th2 (IL-4, IL-5 and IL-13 cytokines. Relative amounts followed a CD8α>DN>CD4 pattern for Th1 and CD4>DN>CD8α for Th2. All iNKT subsets could simultaneously produce IFN-γ and IL-4, but single-positivity for IFN-γ or IL-4 was strikingly rare in CD4(+ and CD8α(+ fractions, respectively. Only CD4(+ iNKT cells produced IL-9 and IL-10; DN cells released IL-17; and none produced IL-22. All iNKT subsets upregulated CD40L upon glycolipid stimulation and induced IL-10 and IL-12 secretion by dendritic cells. Thus, subset composition of iNKT cells is a major determinant of function. Use of enriched CD8α(+, DN or CD4(+ iNKT cells may optimally harness the immunoregulatory properties of iNKT cells for treatment of disease.

Targeted delivery of TLR ligands to human and mouse dendritic cells strongly enhances adjuvanticity.

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Tacken, Paul J; Zeelenberg, Ingrid S; Cruz, Luis J; van Hout-Kuijer, Maaike A; van de Glind, Gerline; Fokkink, Remco G; Lambeck, Annechien J A; Figdor, Carl G

2011-12-22

Effective vaccines consist of 2 components: immunodominant antigens and effective adjuvants. Whereas it has been demonstrated that targeted delivery of antigens to dendritic cells (DCs) improves vaccine efficacy, we report here that co-targeting of TLR ligands (TLRLs) to DCs strongly enhances adjuvanticity and immunity. We encapsulated ligands for intracellular TLRs within biodegradable nanoparticles coated with Abs recognizing DC-specific receptors. Targeted delivery of TLRLs to human DCs enhanced the maturation and production of immune stimulatory cytokines and the Ag-specific activation of naive CD8(+) T cells. In vivo studies demonstrated that nanoparticles carrying Ag induced cytotoxic T-lymphocyte responses at 100-fold lower adjuvant dose when TLRLs were co-encapsulated instead of administered in soluble form. Moreover, the efficacy of these targeted TLRLs reduced the serum cytokine storm and related toxicity that is associated with administration of soluble TLRLs. We conclude that the targeted delivery of adjuvants may improve the efficacy and safety of DC-based vaccines.

Surfactant-ligand co-assisted solvothermal technique for the synthesis of different-shaped CdS nanorod-based materials

International Nuclear Information System (INIS)

Bao Chunyan; Jin Ming; Lu Ran; Xue Pengchong; Zhang Qinglin; Wang Dejun; Zhao Yingying

2003-01-01

1-D nanorods, twinrods, golfclubs, and tripods of CdS were prepared via a surfactant-ligand co-assisted solvothermal method at 160 deg. C. The surfactant of S-dodecylisothiounium bromide (C 12 ) used in the process was favorable for synthesis of different-shaped CdS nanorod with high aspect ratio. X-ray diffraction (XRD) and TEM images showed that the 1-D nanorods had wurtzite phase and others had a zinc blende core and wurtzite arms. The morphologies of CdS prepared under different conditions suggested the 'template-assistance' of the surfactant and that the nonaqueous organic media are important for the self-assembling of inorganic components at atomic level

Roles of the kinase TAK1 in TRAF6-dependent signaling by CD40 and its oncogenic viral mimic, LMP1.

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Kelly M Arcipowski

Full Text Available The Epstein-Barr virus (EBV-encoded protein latent membrane protein 1 (LMP1 is essential for EBV-mediated B cell transformation and plays a critical role in the development of post-transplant B cell lymphomas. LMP1 also contributes to the exacerbation of autoimmune diseases such as systemic lupus erythematosus (SLE. LMP1 is a functional mimic of the tumor necrosis factor receptor (TNFR superfamily member CD40, and relies on TNFR-associated factor (TRAF adaptor proteins to mediate signaling. However, LMP1 activation signals to the B cell are amplified and sustained compared to CD40 signals. We previously demonstrated that LMP1 and CD40 use TRAF molecules differently. Although associating with CD40 and LMP1 via separate mechanisms, TRAF6 plays a significant role in signal transduction by both. It is unknown whether TRAF6 mediates CD40 versus LMP1 functions via distinct or shared pathways. In this study, we tested the hypothesis that TRAF6 uses the kinase TAK1 to trigger important signaling pathways following both CD40 and LMP1 stimulation. We determined that TAK1 was required for JNK activation and interleukin-6 (IL-6 production mediated by CD40 and LMP1, in both mouse and human B cells. Additionally, TRAF3 negatively regulated TRAF6-dependent, CD40-mediated TAK1 activation by limiting TRAF6 recruitment. This mode of regulation was not observed for LMP1 and may contribute to the dysregulation of LMP1 compared to CD40 signals.

Safety and efficacy of the CD95-ligand inhibitor asunercept in transfusion-dependent patients with low and intermediate risk MDS.

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Boch, Tobias; Luft, Thomas; Metzgeroth, Georgia; Mossner, Maximilian; Jann, Johann-Christoph; Nowak, Daniel; Meir, Franziska La; Schumann, Christiane; Klemmer, Jennifer; Brendel, Susanne; Fricke, Harald; Kunz, Claudia; Weiß, Christel; Hofmann, Wolf-Karsten; Nolte, Florian

2018-05-01

In low risk MDS, increased apoptosis of erythroid progenitors mediated via CD95 (Fas) activation has been described to result in peripheral cytopenia. Blockade of the CD95 system can improve erythropoiesis in MDS. Asunercept (APG101) is a fusion protein consisting of the extracellular domain of human CD95 and the Fc domain of human IgG1 blocking the interaction between CD95 and its ligand. Here we report on results from a phase I study in 20 transfusion-dependent low and intermediate risk MDS patients treated with intravenous asunercept (EudraCT 2012-003027-37). Primary objectives were safety and tolerability as well as pharmacodynamic effects. Secondary objectives were hematologic improvement, incidence and time to leukemic progression as well as overall survival. Frequency and severity of adverse events were in range of what could be expected in a patient cohort comprising of elderly MDS patients. Two patients experienced a serious adverse event with a suspected relationship to asunercept. The incidence of disease progression was low. In the 20 patients a decrease of the transfusion need from a mean of 10,8 (±5,1) pRBCs during the 12 weeks treatment phase to a mean of 10,0 (±4,2) pRBCs at the end of the study was observed. In conclusion, asunercept was well tolerated and showed efficacy in transfusion-dependent low and intermediate risk MDS patients. Further clinical investigation is warranted, particularly in combination with erythropoiesis stimulating agents (ESAs). Copyright © 2018. Published by Elsevier Ltd.

[Evaluation of percentage of lymphocytes B with expression of co-receptors CD 40, CD22 and CD72 in hypertrophied adenoid at children with otitis media with effusion].

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Wysocka, Jolanta; Zelazowska-Rutkowska, Beata; Ratomski, Karol; Skotnicka, Bozena; Hassmann-Poznańska, Elzbieta

2009-01-01

In hypertrophied adenoid lymphocytes B make up about 60% all lymphocytes. When the lymphocytes B come in interaction with antigens this membranes signal be passed through their receptor (BCR) to interior of cell. This signal affect modulation on gene expression, activation from which depends activation, anergy or apoptosis of lymphocyte B. Accompany BCR co-receptors regulate his functions influence stimulate or inhibitive. To the most important co-receptors stepping out on lymphocyte B belong: CD40, CD22, CD72. The aim of study was evaluation of lymphocytes B (CD19) with co-expression with CD72 and CD40 receptors in hypertrophied adenoid with at children with otitis media with effusion. An investigation was executed in hypertrophied adenoids with or without otitis media with effusion. By flow cytometry percentage of lymphocytes B with co-receptors CD 40, CD22 and CD72 in was analyzed. The percentages of CD19+CD72+ lymphocytes in the group of children with adenoid hypertrophy and exudative otitis media were lower as compared to the reference group. However, the percentages of CD19+CD22+, CD19+CD40+ in the study group was approximate to the reference group. The lower percentage of lymphocytes B CD72 + near approximate percentages of lymphocytes B CD40+ and BCD22+ at children with otitis media with effusion can be the cause of incorrect humoral response in hypertrophied adenoid at children. Maybe it is cause reduced spontaneous production IgA and IgG through lymphocyte at children with otitis media with effusion.

Evaluation of CD40 and CD80 receptors in the colonic mucosal membrane of children with inflammatory bowel disease

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Barbara Kamińska

2015-12-01

Full Text Available [b][/b][b]Introduction. [/b]The most prevalent inflammatory bowel diseases (IBD include ulcerative colitis (UC and Crohn’s disease (CD. Immune processes play a vital role in the etiopathogenesis of these conditions, involving both cellular and humoral response mechanisms. The aim of this study was to quantify CD40- and CD80-positive cells in the biopsy specimens of large intestinal mucosa from children with IBD. [b]Materials and method. [/b]The study comprised 38 children aged between 3–17 years (mean 11.5±3.7 years – 20 boys (52.6 % and 18 girls (47.4%. Eighteen patients were diagnosed with UC on the basis of clinical manifestation, endoscopic and histopathological findings. Mean age of this subgroup was 11.55±4.07 years. A group of 10 children (mean age 12.30±2.83 diagnosed with CD was also included. The control group comprised 10 IBD-free children (mean age 10.28±4.07 years. The surface expressions of CD40 and CD80 were analyzed in large intestine mucosa biopsy specimens, fixed in formaldehyde, embedded in paraffin, and cut with a microtome into 4 µm slices. [b]Results. [/b]The number of CD40- and CD80-positive cells in the large intestinal mucosa of children with Crohn’s disease and ulcerative colitis was significantly higher than in the controls. The highest number of CD40+ and CD80+ cells was observed in the caecal mucosal membrane of Crohn’s disease patients and in the rectal mucosa of individuals with ulcerative colitis. [b]Conclusion.[/b] IBD is characterized by elevated, segment-specific, expression of CD40 and CD80.

CD70 reverse signaling enhances NK cell function and immunosurveillance in CD27-expressing B-cell malignancies.

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Al Sayed, Mohamad F; Ruckstuhl, Carla A; Hilmenyuk, Tamara; Claus, Christina; Bourquin, Jean-Pierre; Bornhauser, Beat C; Radpour, Ramin; Riether, Carsten; Ochsenbein, Adrian F

2017-07-20

The interaction of the tumor necrosis factor receptor (TNFR) CD27 with its ligand CD70 is an emerging target to treat cancer. CD27 signaling provides costimulatory signals to cytotoxic T cells but also increases the frequency of regulatory T cells. Similar to other TNFR ligands, CD70 has been shown to initiate intracellular signaling pathways (CD70 reverse signaling). CD27 is expressed on a majority of B-cell non-Hodgkin lymphoma, but its role in the immune control of lymphoma and leukemia is unknown. We therefore generated a cytoplasmic deletion mutant of CD27 (CD27-trunc) to study the role of CD70 reverse signaling in the immunosurveillance of B-cell malignancies in vivo. Expression of CD27-trunc on malignant cells increased the number of tumor-infiltrating interferon γ-producing natural killer (NK) cells. In contrast, the antitumoral T-cell response remained largely unchanged. CD70 reverse signaling in NK cells was mediated via the AKT signaling pathway and increased NK cell survival and effector function. The improved immune control by activated NK cells prolonged survival of CD27-trunc-expressing lymphoma-bearing mice. Finally, CD70 reverse signaling enhanced survival and effector function of human NK cells in a B-cell acute lymphoblastic leukemia xenotransplants model. Therefore, CD70 reverse signaling in NK cells contributes to the immune control of CD27-expressing B-cell lymphoma and leukemia. © 2017 by The American Society of Hematology.

New Mn(II, Ni(II, Cd(II, Pb(II complexes with 2-methylbenzimidazole and other ligands. Synthesis, spectroscopic characterization, crystal structure, magnetic susceptibility and biological activity studies

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Shayma A. Shaker

2016-11-01

Full Text Available Synthesis and characterization of Mn(II, Ni(II, Cd(II and Pb(II mixed ligand complexes of 2-methylbenzimidazole with other ligands have been reported. The structure of the ligands and their complexes was investigated using elemental analysis, IR, UV–Vis, (1H, 13C NMR spectroscopy, molar conductivity and magnetic susceptibility measurements. In all the studies of complexes, the 2-methylbenzimidazole behaves as a neutral monodentate ligand which is coordinated with the metal ions through the N atom. While benzotriazole behaves as a neutral bidentate ligand which is coordinated with the Ni(II ion through the two N atoms. Moreover, the N-acetylglycine behaves as a bidentate ligand which is coordinated with the Mn(II, Ni(II and Pb(II ions through the N atom and the terminal carboxyl oxygen atom. The magnetic and spectral data indicate the tetrahedral geometry for Mn(II complex, irregular tetrahedral geometry for Pb(II complex and octahedral geometry for Ni(II complex. The X-ray single crystal diffraction method was used to confirm a centrosymmetric dinuclear Cd(II complex as each two metal ions are linked by a pair of thiocyanate N = S bridge. Two 2-methylbenzimidazole N-atom donors and one terminal thiocyanate N atom complete a highly distorted square pyramid geometry around the Cd atom. Besides, different cell types were used to determine the inhibitory effect of Mn(II, Ni(II, Cd(II and Pb(II complexes on cell growth using MTT assay. Cd(II complex showed cytotoxic effect on various types of cancer cell lines with different EC50 values.

Specific blockade by CD54 and MHC II of CD40-mediated signaling for B cell proliferation and survival

DEFF Research Database (Denmark)

Doyle, I S; Hollmann, C A; Crispe, I N

2001-01-01

Regulation of B lymphocyte proliferation is critical to maintenance of self-tolerance, and intercellular interactions are likely to signal such regulation. Here, we show that coligation of either the adhesion molecule ICAM-1/CD54 or MHC II with CD40 inhibited cell cycle progression and promoted...... these effects. Addition of BCR or IL-4 signals did not overcome the effect of ICAM-1 or MHC II on CD40-induced proliferation. FasL expression was not detected in B cell populations. These results show that MHC II and ICAM-1 specifically modulate CD40-mediated signaling, so inhibiting proliferation...

Complete identification of E-selectin ligand activity on neutrophils reveals a dynamic interplay and distinct functions of PSGL-1, ESL-1 and CD44

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Wild, Martin; Vestweber, Dietmar; Frenette, Paul S.

2014-01-01

SUMMARY The selectins and their ligands are required for leukocyte extravasation during inflammation. Several glycoproteins have been suggested to bind to E-selectin in vitro but the complete identification of its physiological ligands has remained elusive. Here, we show using gene- and RNA-targeted loss-of-function that E-selectin ligand-1 (ESL-1), PSGL-1 and CD44 encompass all endothelial selectin ligand activity on neutrophils. PSGL-1 plays a major role in the initial leukocyte capture, while ESL-1 is critical to convert initial tethers into steady slow rolling. CD44 controls rolling velocity and mediates E-selectin-dependent redistribution of PSGL-1 and L-selectin to a major pole on slowly rolling leukocytes through p38 signaling. These results suggest distinct and dynamic contributions of these three glycoproteins in selectin-mediated neutrophil adhesion and signaling. PMID:17442598

Targeting CD28, CTLA-4 and PD-L1 costimulation differentially controls immune synapses and function of human regulatory and conventional T-cells.

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Nahzli Dilek

Full Text Available CD28, CTLA-4 and PD-L1, the three identified ligands for CD80/86, are pivotal positive and negative costimulatory molecules that, among other functions, control T cell motility and formation of immune synapse between T cells and antigen-presenting cells (APCs. What remains incompletely understood is how CD28 leads to the activation of effector T cells (Teff but inhibition of suppression by regulatory T cells (Tregs, while CTLA-4 and PD-L1 inhibit Teff function but are crucial for the suppressive function of Tregs. Using alloreactive human T cells and blocking antibodies, we show here by live cell dynamic microscopy that CD28, CTLA-4, and PD-L1 differentially control velocity, motility and immune synapse formation in activated Teff versus Tregs. Selectively antagonizing CD28 costimulation increased Treg dwell time with APCs and induced calcium mobilization which translated in increased Treg suppressive activity, in contrast with the dampening effect on Teff responses. The increase in Treg suppressive activity after CD28 blockade was also confirmed with polyclonal Tregs. Whereas CTLA-4 played a critical role in Teff by reversing TCR-induced STOP signals, it failed to affect motility in Tregs but was essential for formation of the Treg immune synapse. Furthermore, we identified a novel role for PD-L1-CD80 interactions in suppressing motility specifically in Tregs. Thus, our findings reveal that the three identified ligands of CD80/86, CD28, CTLA-4 and PD-L1, differentially control immune synapse formation and function of the human Teff and Treg cells analyzed here. Individually targeting CD28, CTLA-4 and PD-L1 might therefore represent a valuable therapeutic strategy to treat immune disorders where effector and regulatory T cell functions need to be differentially targeted.

Anti-leukemic activity and tolerability of anti-human CD47 monoclonal antibodies

Science.gov (United States)

Pietsch, E C; Dong, J; Cardoso, R; Zhang, X; Chin, D; Hawkins, R; Dinh, T; Zhou, M; Strake, B; Feng, P-H; Rocca, M; Santos, C Dos; Shan, X; Danet-Desnoyers, G; Shi, F; Kaiser, E; Millar, H J; Fenton, S; Swanson, R; Nemeth, J A; Attar, R M

2017-01-01

CD47, a broadly expressed cell surface protein, inhibits cell phagocytosis via interaction with phagocyte-expressed SIRPα. A variety of hematological malignancies demonstrate elevated CD47 expression, suggesting that CD47 may mediate immune escape. We discovered three unique CD47-SIRPα blocking anti-CD47 monoclonal antibodies (mAbs) with low nano-molar affinity to human and cynomolgus monkey CD47, and no hemagglutination and platelet aggregation activity. To characterize the anti-cancer activity elicited by blocking CD47, the mAbs were cloned into effector function silent and competent Fc backbones. Effector function competent mAbs demonstrated potent activity in vitro and in vivo, while effector function silent mAbs demonstrated minimal activity, indicating that blocking CD47 only leads to a therapeutic effect in the presence of Fc effector function. A non-human primate study revealed that the effector function competent mAb IgG1 C47B222-(CHO) decreased red blood cells (RBC), hematocrit and hemoglobin by >40% at 1 mg/kg, whereas the effector function silent mAb IgG2σ C47B222-(CHO) had minimal impact on RBC indices at 1 and 10 mg/kg. Taken together, our findings suggest that targeting CD47 is an attractive therapeutic anti-cancer approach. However, the anti-cancer activity observed with anti-CD47 mAbs is Fc effector dependent as are the side effects observed on RBC indices. PMID:28234345

CD8αα expression marks terminally differentiated human CD8+ T cells expanded in chronic viral infection

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Lucy Jane Walker

2013-08-01

Full Text Available The T cell co-receptor CD8αβ enhances T cell sensitivity to antigen, however studies indicate CD8αα has the converse effect and acts as a co-repressor. Using a combination of Thymic Leukaemia antigen (TL tetramer, which directly binds CD8αα, anti-CD161 and anti-Vα7.2 antibodies we have been able for the first time to clearly define CD8αα expression on human CD8 T cells subsets. In healthy controls CD8αα is most highly expressed by CD161 bright (CD161++ mucosal associated invariant T (MAIT cells, with CD8αα expression highly restricted to the TCR Vα7.2+ cells of this subset. We also identified CD8αα-expressing populations within the CD161 mid (CD161+ and negative (CD161- non-MAIT CD8 T cell subsets and show TL-tetramer binding to correlate with expression of CD8β at low levels in the context of maintained CD8α expression (CD8α+CD8βlow. In addition, we found CD161-CD8α+CD8βlow populations to be significantly expanded in the peripheral blood of HIV-1 and hepatitis B (mean of 47% and 40% of CD161- T cells respectively infected individuals. Such CD8αα expressing T cells are an effector-memory population (CD45RA-, CCR7-, CD62L- that express markers of activation and maturation (HLA-DR+, CD28-, CD27-, CD57+ and are functionally distinct, expressing greater levels of TNF-α and IFN-γ on stimulation and perforin at rest than their CD8α+CD8βhigh counterparts. Antigen-specific T cells in HLA-B*4201+HIV-1 infected patients are found within both the CD161-CD8α+CD8βhigh and CD161-CD8α+CD8βlow populations. Overall we have clearly defined CD8αα expressing human T cell subsets using the TL-tetramer, and have demonstrated CD161-CD8α+CD8βlow populations, highly expanded in disease settings, to co-express CD8αβ and CD8αα. Co-expression of CD8αα on CD8αβ T cells may impact on their overall function in-vivo and contribute to the distinctive phenotype of highly differentiated populations in HBV and HIV-1 infection.

Diverse Cd(II) compounds based on N-benzoyl-L-glutamic acid and N-donor ligands: Structures and photoluminescent properties

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Ma, Ning; Guo, Wei-Ying; Song, Hui-Hua; Yu, Hai-Tao

2016-01-01

Five new Cd(II) coordination polymers with N-benzoyl-L-glutamic acid (H2bzgluO) and different N-donor ligands, [Cd(bzgluO)(2,2‧-bipy)(H2O)]n (1), [Cd(bzgluO)(2,4‧-bipy)2(H2O)·3H2O]n (2), [Cd(bzgluO)(phen)·H2O]n (3), [Cd(bzgluO)(4,4‧-bipy)(H2O)]n (4), [Cd(bzgluO)(bpp)(H2O)·2H2O]n (5) were synthesized (2,2‧-bipy=2,2‧-bipyridine, 2,4‧-bipy=2,4‧-bipyridine, phen=1,10-phenanthroline, 4,4‧-bipy=4,4‧-bipyridine, bpp=1,3-di(4-pyridyl)propane). Compounds 1-2 exhibit a 1D single-chain structure. Compound 1 generates a 2D supramolecular structure via π-π stacking and hydrogen bonding, 3D architecture of compound 2 is formed by hydrogen bonding. Compound 3 features a 1D double-chain structure, which are linked by π-π interactions into a 2D supramolecular layer. Compounds 4-5 display a 2D network structure. Neighboring layers of 4 are extended into a 3D supramolecular architecture through hydrogen bonding. The structural diversity of these compounds is attributed to the effect of ancillary N-donor ligands and coordination modes of H2bzgluO. Luminescent properties of 1-5 were studied at room temperature. Circular dichroism of compounds 1, 2 and 5 were investigated.

Characterization of a Broadly Reactive Anti-CD40 Agonistic Monoclonal Antibody for Potential Use as an Adjuvant.

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Cameron Martin

Full Text Available Lack of safe and effective adjuvants is a major hindrance to the development of efficacious vaccines. Signaling via CD40 pathway leads to enhanced antigen processing and presentation, nitric oxide expression, pro-inflammatory cytokine expression by antigen presenting cells, and stimulation of B-cells to undergo somatic hypermutation, immunoglobulin class switching, and proliferation. Agonistic anti-CD40 antibodies have shown promising adjuvant qualities in human and mouse vaccine studies. An anti-CD40 monoclonal antibody (mAb, designated 2E4E4, was identified and shown to have strong agonistic effects on primary cells from multiple livestock species. The mAb recognize swine, bovine, caprine, and ovine CD40, and evoked 25-fold or greater proliferation of peripheral blood mononuclear cells (PBMCs from these species relative to cells incubated with an isotype control (p<0.001. In addition, the mAb induced significant nitric oxide (p<0.0001 release by bovine macrophages. Furthermore, the mAb upregulated the expression of MHC-II by PBMCs, and stimulated significant (p<0.0001 IL-1α, IL6, IL-8, and TNF-α expression by PBMCs. These results suggest that the mAb 2E4E4 can target and stimulate cells from multiple livestock species and thus, it is a potential candidate for adjuvant development. This is the first study to report an anti-swine CD40 agonistic mAb that is also broadly reactive against multiple species.

p62 regulates CD40-mediated NFκB activation in macrophages through interaction with TRAF6

Energy Technology Data Exchange (ETDEWEB)

Seibold, Kristina; Ehrenschwender, Martin, E-mail: martin.ehrenschwender@ukr.de

2015-08-14

CD40 is a member of the tumor necrosis factor (TNF) receptor family. Activation-induced recruitment of adapter proteins, so-called TNF-receptor-associated factors (TRAFs) to the cytoplasmic tail of CD40 triggers signaling cascades important in the immune system, but has also been associated with excessive inflammation in diseases such as atherosclerosis and rheumatoid arthritis. Especially, pro-inflammatory nuclear factor κB (NFκB) signaling emanating from CD40-associated TRAF6 appears to be a key pathogenic driving force. Consequently, targeting the CD40-TRAF6 interaction is emerging as a promising therapeutic strategy, but the underlying molecular machinery of this signaling axis is to date poorly understood. Here, we identified the multifunctional adaptor protein p62 as a critical regulator in CD40-mediated NFκB signaling via TRAF6. CD40 activation triggered formation of a TRAF6-p62 complex. Disturbing this interaction tremendously reduced CD40-mediated NFκB signaling in macrophages, while TRAF6-independent signaling pathways remained unaffected. This highlights p62 as a potential target in hyper-inflammatory, CD40-associated pathologies. - Highlights: • CD40 activation triggers interaction of the adapter protein TRAF6 with p62. • TRAF6-p62 interaction regulates CD40-mediated NFκB signaling in macrophages. • Defective TRAF6-p62 interaction reduces CD40-mediated NFκB activation in macrophages.

Ex Vivo Expanded Human Non-Cytotoxic CD8+CD45RClow/− Tregs Efficiently Delay Skin Graft Rejection and GVHD in Humanized Mice

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Séverine Bézie

2018-01-01

Full Text Available Both CD4+ and CD8+ Tregs play a critical role in the control of immune responses and immune tolerance; however, our understanding of CD8+ Tregs is limited while they are particularly promising for therapeutic application. We report here existence of highly suppressive human CD8+CD45RClow/− Tregs expressing Foxp3 and producing IFNγ, IL-10, IL-34, and TGFβ to mediate their suppressive activity. We demonstrate that total CD8+CD45RClow/− Tregs can be efficiently expanded in the presence of anti-CD3/28 mAbs, high-dose IL-2 and IL-15 and that such expanded Tregs efficiently delay GVHD and human skin transplantation rejection in immune humanized mice. Robustly expanded CD8+ Tregs displayed a specific gene signature, upregulated cytokines and expansion in the presence of rapamycin greatly improved proliferation and suppression. We show that CD8+CD45RClow/− Tregs are equivalent to canonical CD4+CD25highCD127low/− Tregs for suppression of allogeneic immune responses in vitro. Altogether, our results open new perspectives to tolerogenic strategies in human solid organ transplantation and GVHD.

Genetic adjuvantation of recombinant MVA with CD40L potentiates CD8 T cell mediated immunity

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Henning eLauterbach

2013-08-01

Full Text Available Modified vaccinia Ankara (MVA is a safe and promising viral vaccine vector that is currently investigated in several clinical and pre-clinical trials. In contrast to inactivated or sub-unit vaccines, MVA is able to induce strong humoral as well as cellular immune responses. In order to further improve its CD8 T cell inducing capacity, we genetically adjuvanted MVA with the coding sequence of murine CD40L, a member of the tumor necrosis factor (TNF superfamily. Immunization of mice with this new vector led to strongly enhanced primary and memory CD8 T cell responses. Concordant with the enhanced CD8 T cell response, we could detect stronger activation of dendritic cells and higher systemic levels of innate cytokines (including IL-12p70 early after immunization. Interestingly, acquisition of memory characteristics (i.e., IL-7R expression was accelerated after immunization with MVA-CD40L in comparison to non-adjuvanted MVA. Furthermore, the generated CTLs also showed improved functionality as demonstrated by intracellular cytokine staining and in vivo killing activity. Importantly, the superior CTL response after a single MVA-CD40L immunization was able to protect B cell deficient mice against a fatal infection with ectromelia virus. Taken together, we show that genetic adjuvantation of MVA can change strength, quality and functionality of innate and adaptive immune responses. These data should facilitate a rational vaccine design with a focus on rapid induction of large numbers of CD8 T cells able to protect against specific diseases.

NKG2D Ligands in Tumor Immunity: Two Sides of a Coin

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Jennifer eWu

2015-03-01

Full Text Available The activating/co-stimulatory receptor NKG2D (natural-killer group 2, member D is expressed on the surface of all human NK, NKT, CD8+ T and subsets of γδ+ T cells. The significance of NKG2D function in tumor immunity has been well demonstrated in experimental animal models. However, the role of human NKG2D ligands in regulating tumor immunity and cancer prognosis had been controversial in the literature. In this review, we summarize the latest advancement, discuss the controversies, and present evidence that membrane-bound and soluble NKG2D ligands oppositely regulate tumor immunity. We also discuss new perspectives of targeting NKG2D ligands for cancer immunotherapy.

EBV promotes human CD8 NKT cell development.

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Yuling He

2010-05-01

Full Text Available The reports on the origin of human CD8(+ Valpha24(+ T-cell receptor (TCR natural killer T (NKT cells are controversial. The underlying mechanism that controls human CD4 versus CD8 NKT cell development is not well-characterized. In the present study, we have studied total 177 eligible patients and subjects including 128 healthy latent Epstein-Barr-virus(EBV-infected subjects, 17 newly-onset acute infectious mononucleosis patients, 16 newly-diagnosed EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. We have established human-thymus/liver-SCID chimera, reaggregated thymic organ culture, and fetal thymic organ culture. We here show that the average frequency of total and CD8(+ NKT cells in PBMCs from 128 healthy latent EBV-infected subjects is significantly higher than in 17 acute EBV infectious mononucleosis patients, 16 EBV-associated Hodgkin lymphoma patients, and 16 EBV-negative normal control subjects. However, the frequency of total and CD8(+ NKT cells is remarkably increased in the acute EBV infectious mononucleosis patients at year 1 post-onset. EBV-challenge promotes CD8(+ NKT cell development in the thymus of human-thymus/liver-SCID chimeras. The frequency of total (3% of thymic cells and CD8(+ NKT cells ( approximately 25% of NKT cells is significantly increased in EBV-challenged chimeras, compared to those in the unchallenged chimeras (<0.01% of thymic cells, CD8(+ NKT cells undetectable, respectively. The EBV-induced increase in thymic NKT cells is also reflected in the periphery, where there is an increase in total and CD8(+ NKT cells in liver and peripheral blood in EBV-challenged chimeras. EBV-induced thymic CD8(+ NKT cells display an activated memory phenotype (CD69(+CD45RO(hiCD161(+CD62L(lo. After EBV-challenge, a proportion of NKT precursors diverges from DP thymocytes, develops and differentiates into mature CD8(+ NKT cells in thymus in EBV-challenged human-thymus/liver-SCID chimeras or

CD40-mediated apoptosis in murine B-lymphoma lines containing mutated p53

DEFF Research Database (Denmark)

Hollmann, Annette C; Gong, Qiaoke; Owens, Trevor

2002-01-01

Crosslinking CD40 induces normal B-cells to proliferate and differentiate but causes many tumor cell lines to undergo apoptosis. As p53 is required for many apoptotic pathways, we analyzed the effects of CD40 ligation and their correlation with p53 function in four murine B-lymphoma lines. A20...... of detectable p21 mRNA in A20 and M12 cells. P21 mRNA was increased to detectable levels in M12 cells upon CD40 ligation; however, blocking this effect with the p53 inhibitor pifithrin had no effect on CD40-mediated apoptosis. Sequencing showed that p53 in A20 and M12 cells contained point mutations leading...... to amino acid substitutions in DNA binding regions, but was unmutated in WEHI231 and WEHI 279. These results suggest that CD40-mediated apoptosis can occur in the absence of functional p53....

Stability Investigation of Ligand-Exchanged CdSe/ZnS-Y (Y = 3-Mercaptopropionic Acid or Mercaptosuccinic Acid through Zeta Potential Measurements

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Ngoc Thuy Vo

2016-01-01

Full Text Available Quantum dots have been considered to be promising candidates for bioapplications because of their high sensitivity, rapid response, and reliability. The synthesis of high-quality quantum dots that can be dissolved in water and other biological media is a crucial step toward their further application in biology. Starting with a one-pot reaction and the successive ionic layer adsorption and reaction (SILAR method, we produced the CdSe/ZnS core/shell structure. Through a ligand-exchange mechanism, we coated the as-made CdSe/ZnS structure with 3-mercaptopropionic acid (MPA or mercaptosuccinic acid (MSA. Various techniques, including photoluminescence (PL, ultraviolet-visible (UV-Vis spectroscopy, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Fourier transform infrared (FTIR spectroscopy, were utilized to characterize the ligand-coated CdSe/ZnS structure. The results show enhanced luminescence intensity, CdSe surface passivation by ZnS, and successful coating with MPA and MSA. The stability of quantum dots in solutions with different pH values was investigated by performing zeta potential measurements. The results revealed that the quantum dots shifted from displaying hydrophobic to hydrophilic behavior and could be connected with bioagents.

Human Endometrial CD98 Is Essential for Blastocyst Adhesion

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Domínguez, Francisco; Simón, Carlos; Quiñonero, Alicia; Ramírez, Miguel Ángel; González-Muñoz, Elena; Burghardt, Hans; Cervero, Ana; Martínez, Sebastián; Pellicer, Antonio; Palacín, Manuel; Sánchez-Madrid, Francisco; Yáñez-Mó, María

2010-01-01

Background Understanding the molecular basis of embryonic implantation is of great clinical and biological relevance. Little is currently known about the adhesion receptors that determine endometrial receptivity for embryonic implantation in humans. Methods and Principal Findings Using two human endometrial cell lines characterized by low and high receptivity, we identified the membrane receptor CD98 as a novel molecule selectively and significantly associated with the receptive phenotype. In human endometrial samples, CD98 was the only molecule studied whose expression was restricted to the implantation window in human endometrial tissue. CD98 expression was restricted to the apical surface and included in tetraspanin-enriched microdomains of primary endometrial epithelial cells, as demonstrated by the biochemical association between CD98 and tetraspanin CD9. CD98 expression was induced in vitro by treatment of primary endometrial epithelial cells with human chorionic gonadotropin, 17-β-estradiol, LIF or EGF. Endometrial overexpression of CD98 or tetraspanin CD9 greatly enhanced mouse blastocyst adhesion, while their siRNA-mediated depletion reduced the blastocyst adhesion rate. Conclusions These results indicate that CD98, a component of tetraspanin-enriched microdomains, appears to be an important determinant of human endometrial receptivity during the implantation window. PMID:20976164

CD40L induces functional tunneling nanotube networks exclusively in dendritic cells programmed by mediators of type 1 immunity.

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Zaccard, Colleen R; Watkins, Simon C; Kalinski, Pawel; Fecek, Ronald J; Yates, Aarika L; Salter, Russell D; Ayyavoo, Velpandi; Rinaldo, Charles R; Mailliard, Robbie B

2015-02-01

The ability of dendritic cells (DC) to mediate CD4(+) T cell help for cellular immunity is guided by instructive signals received during DC maturation, as well as the resulting pattern of DC responsiveness to the Th signal, CD40L. Furthermore, the professional transfer of antigenic information from migratory DC to lymph node-residing DC is critical for the effective induction of cellular immune responses. In this study we report that, in addition to their enhanced IL-12p70 producing capacity, human DC matured in the presence of inflammatory mediators of type 1 immunity are uniquely programmed to form networks of tunneling nanotube-like structures in response to CD40L-expressing Th cells or rCD40L. This immunologic process of DC reticulation facilitates intercellular trafficking of endosome-associated vesicles and Ag, but also pathogens such HIV-1, and is regulated by the opposing roles of IFN-γ and IL-4. The initiation of DC reticulation represents a novel helper function of CD40L and a superior mechanism of intercellular communication possessed by type 1 polarized DC, as well as a target for exploitation by pathogens to enhance direct cell-to-cell spread. Copyright © 2015 by The American Association of Immunologists, Inc.

Human CD56bright NK Cells

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Michel, Tatiana; Poli, Aurélie; Cuapio, Angelica

2016-01-01

Human NK cells can be subdivided into various subsets based on the relative expression of CD16 and CD56. In particular, CD56(bright)CD16(-/dim) NK cells are the focus of interest. They are considered efficient cytokine producers endowed with immunoregulatory properties, but they can also become c...... NK cell subsets is not fully defined, nor is their precise hematopoietic origin. In this article, we summarize recent studies about CD56(bright) NK cells in health and disease and briefly discuss the current controversies surrounding them....

CD1 and mycobacterial lipids activate human T cells.

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Van Rhijn, Ildiko; Moody, D Branch

2015-03-01

For decades, proteins were thought to be the sole or at least the dominant source of antigens for T cells. Studies in the 1990s demonstrated that CD1 proteins and mycobacterial lipids form specific targets of human αβ T cells. The molecular basis by which T-cell receptors (TCRs) recognize CD1-lipid complexes is now well understood. Many types of mycobacterial lipids function as antigens in the CD1 system, and new studies done with CD1 tetramers identify T-cell populations in the blood of tuberculosis patients. In human populations, a fundamental difference between the CD1 and major histocompatibility complex systems is that all humans express nearly identical CD1 proteins. Correspondingly, human CD1 responsive T cells show evidence of conserved TCRs. In addition to natural killer T cells and mucosal-associated invariant T (MAIT cells), conserved TCRs define other subsets of human T cells, including germline-encoded mycolyl-reactive (GEM) T cells. The simple immunogenetics of the CD1 system and new investigative tools to measure T-cell responses in humans now creates a situation in which known lipid antigens can be developed as immunodiagnostic and immunotherapeutic reagents for tuberculosis disease. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Synergy of anti-CD40, CpG and MPL in activation of mouse macrophages.

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Shi, Yongyu; Felder, Mildred A R; Sondel, Paul M; Rakhmilevich, Alexander L

2015-08-01

Activation of macrophages is a prerequisite for their antitumor effects. Several reagents, including agonistic anti-CD40 monoclonal antibody (anti-CD40), CpG oligodeoxynucleotides (CpG) and monophosphoryl lipid A (MPL), can stimulate activation of macrophages. Our previous studies showed synergy between anti-CD40 and CpG and between anti-CD40 and MPL in macrophage activation and antitumor efficacy in mice. In the present study, we asked whether there was synergy among these three reagents. The activation of adherent peritoneal exudate cells (PEC) obtained from mice injected with anti-CD40 and then treated with CpG and/or MPL in vitro was determined by their ability to suppress proliferation of tumor cells and to produce various cytokines and chemokines in vitro. Cell sorting and histology followed by functional testing showed that macrophages were the main cell population in PEC activated by CD40 ligation in vivo. A combination of anti-CD40, CpG or MPL activated PEC to suppress proliferation of B16 cells and produce nitric oxide far greater than the single reagents or any of the double combinations of these reagents. In addition, the combination of all three reagents activated PEC to secrete IL-12, IFN-γ and MCP-1 to a greater degree than any single reagent or any two combined reagents. These results demonstrate that macrophages can be synergistically activated by anti-CD40, CpG and MPL, suggesting that this novel combined approach might be further investigated as potential cancer therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergy of anti-CD40, CpG and MPL in activation of mouse macrophages

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Shi, Yongyu; Felder, Mildred A.R.; Sondel, Paul M.; Rakhmilevich, Alexander L.

2015-01-01

Activation of macrophages is a prerequisite for their antitumor effects. Several reagents, including agonistic anti-CD40 monoclonal antibody (anti-CD40), CpG oligodeoxynucleotides (CpG) and monophosphoryl lipid A (MPL), can stimulate activation of macrophages. Our previous studies showed synergy between anti-CD40 and CpG and between anti-CD40 and MPL in macrophage activation and antitumor efficacy in mice. In the present study, we asked whether there was synergy among these three reagents. The activation of adherent peritoneal exudate cells (PEC) obtained from mice injected with anti-CD40 and then treated with CpG and/or MPL in vitro was determined by their ability to suppress proliferation of tumor cells and to produce various cytokines and chemokines in vitro. Cell sorting and histology followed by functional testing showed that macrophages were the main cell population in PEC activated by CD40 ligation in vivo. A combination of anti-CD40, CpG or MPL activated PEC to suppress proliferation of B16 cells and produce nitric oxide far greater than the single reagents or any of the double combinations of these reagents. In addition, the combination of all three reagents activated PEC to secrete IL-12, IFN-γ and MCP-1 to a greater degree than any single reagent or any two combined reagents. These results demonstrate that macrophages can be synergistically activated by anti-CD40, CpG and MPL, suggesting that this novel combined approach might be further investigated as potential cancer therapy. PMID:25829245

Blockade of OX40/OX40 ligand to decrease cytokine messenger RNA expression in acute renal allograft rejection in vitro.

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Wang, Y-L; Li, G; Fu, Y-X; Wang, H; Shen, Z-Y

2013-01-01

The aim of this study was to investigate cytokine messenger RNA (mRNA) expression by peripheral blood mononuclear cells (PBMCs) from renal recipients experiencing acute rejection by blocking OX40-OX40L interactions with recombinant human OX40-Fc fusion protein (rhOX40Fc) in vitro. PBMCs were isolated from 20 recipients experiencing acute rejection episodes (rejection group) and 20 recipients with stable graft function (stable group). Levels of Th1 (interferon [IFN]-γ) and Th2 (interleukin [IL]-4) mRNA expressions by PBMCs were measured using real-time reverse transcriptase-polymerase chain reactions. IFN-γ mRNA expression levels were significantly higher in the rejection than the stable group (P rejection group, rhOX40Fc reduced significantly the expression of IFN-γ and IL-4 mRNA by anti-CD3-monoclonal antibody stimulated PBMCs (P type cytokines. Copyright © 2013 Elsevier Inc. All rights reserved.

Activated human neonatal CD8+ T cells are subject to immunomodulation by direct TLR2 or TLR5 stimulation.

LENUS (Irish Health Repository)

McCarron, Mark

2012-02-01

In conditions of optimal priming, the neonate possesses competency to mount quantitatively adult-like responses. Vaccine formulations containing sufficiently potent adjuvants may overcome the neonate\\'s natural tendency for immunosuppression and provoke a similarly robust immune response. TLR expression on T cells represents the possibility of directly enhancing T cell immunity. We examined the ex vivo responsiveness of highly purified human cord blood-derived CD8(+) T cells to direct TLR ligation by a repertoire of TLR agonists. In concert with TCR stimulation, only Pam(3)Cys (palmitoyl-3-Cys-Ser-(Lys)(4)) and flagellin monomers significantly enhanced proliferation, CD25(+) expression, IL-2, IFN-gamma, TNF-alpha, and intracellular granzyme B expression. TLR2 and TLR5 mRNA was detected in the CD8(+) T cells. Blocking studies confirmed that the increase in IFN-gamma production was by the direct triggering of surface TLR2 or TLR5. The simultaneous exposure of CD8(+) T cells to both TLR agonists had an additive effect on IFN-gamma production. These data suggest that a combination of the two TLR ligands would be a potent T cell adjuvant. This may represent a new approach to TLR agonist-based adjuvant design for future human neonatal vaccination strategies requiring a CD8(+) component.

Circulating CD14brightCD16+ 'intermediate' monocytes exhibit enhanced parasite pattern recognition in human helminth infection.

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Joseph D Turner

2014-04-01

Full Text Available Circulating monocyte sub-sets have recently emerged as mediators of divergent immune functions during infectious disease but their role in helminth infection has not been investigated. In this study we evaluated whether 'classical' (CD14brightCD16-, 'intermediate' (CD14brightCD16+, and 'non-classical' (CD14dimCD16+ monocyte sub-sets from peripheral blood mononuclear cells varied in both abundance and ability to bind antigenic material amongst individuals living in a region of Northern Senegal which is co-endemic for Schistosoma mansoni and S. haematobium. Monocyte recognition of excretory/secretory (E/S products released by skin-invasive cercariae, or eggs, of S. mansoni was assessed by flow cytometry and compared between S. mansoni mono-infected, S. mansoni and S. haematobium co-infected, and uninfected participants. Each of the three monocyte sub-sets in the different infection groups bound schistosome E/S material. However, 'intermediate' CD14brightCD16+ monocytes had a significantly enhanced ability to bind cercarial and egg E/S. Moreover, this elevation of ligand binding was particularly evident in co-infected participants. This is the first demonstration of modulated parasite pattern recognition in CD14brightCD16+ intermediate monocytes during helminth infection, which may have functional consequences for the ability of infected individuals to respond immunologically to infection.

Intracellular targeting of CD44+ cells with self-assembling, protein only nanoparticles.

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Pesarrodona, Mireia; Ferrer-Miralles, Neus; Unzueta, Ugutz; Gener, Petra; Tatkiewicz, Witold; Abasolo, Ibane; Ratera, Imma; Veciana, Jaume; Schwartz, Simó; Villaverde, Antonio; Vazquez, Esther

2014-10-01

CD44 is a multifunctional cell surface protein involved in proliferation and differentiation, angiogenesis and signaling. The expression of CD44 is up-regulated in several types of human tumors and particularly in cancer stem cells, representing an appealing target for drug delivery in the treatment of cancer. We have explored here several protein ligands of CD44 for the construction of self-assembling modular proteins designed to bind and internalize target cells. Among five tested ligands, two of them (A5G27 and FNI/II/V) drive the formation of protein-only, ring-shaped nanoparticles of about 14 nm that efficiently bind and penetrate CD44(+) cells by an endosomal route. The potential of these newly designed nanoparticles is evaluated regarding the need of biocompatible nanostructured materials for drug delivery in CD44-linked conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Association of CD40 gene polymorphisms with sporadic breast cancer in Chinese Han women of Northeast China.

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Chen Shuang

Full Text Available BACKGROUND: Breast cancer is a polygenetic disorder with a complex inheritance pattern. Single nucleotide polymorphisms (SNPs, the most common genetic variations, influence not only phenotypic traits, but also interindividual predisposition to disease, treatment outcomes with drugs and disease prognosis. The co-stimulatory molecule CD40 plays a prominent role in immune regulation and homeostasis. Accumulating evidence suggests that CD40 contributes to the pathogenesis of cancer. Here, we set out to test the association between polymorphisms in the CD40 gene and breast carcinogenesis and tumor pathology. METHODOLOGY AND PRINCIPAL FINDINGS: Four SNPs (rs1800686, rs1883832, rs4810485 and rs3765459 were genotyped by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP method in a case-control study including 591 breast cancer patients and 600 age-matched healthy controls. Differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed by the Chi-square test for trends. Our preliminary data showed a statistically significant association between the four CD40 gene SNPs and sporadic breast cancer risk (additive P = 0.0223, 0.0012, 0.0013 and 0.0279, respectively. A strong association was also found using the dominant, recessive and homozygote comparison genetic models. In the clinical features analysis, significant associations were observed between CD40 SNPs and lymph node metastasis, human epidermal growth factor receptor 2 (C-erbB2, estrogen receptor (ER, progesterone receptor (PR and tumor protein 53 (P53 statuses. In addition, our haplotype analysis indicated that the haplotype C(rs1883832G(rs4810485, which was located within the only linkage disequilibrium (LD block identified, was a protective haplotype for breast cancer, whereas T(rs1883832T(rs4810485 increased the risk in the studied population, even after correcting the P value for multiple testing (P = 0.0337 and

Physicochemical, Spectral, and Biological Studies of Mn(II, Cu(II, Cd(II, Zr(OH2(IV, and UO2(VI Compounds with Ligand Containing Thiazolidin-4-one Moiety

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Dinesh Kumar

2014-01-01

Full Text Available The Schiff base (I upon reacting with mercaptoacetic acid in dry benzene undergoes cyclization and forms N-(2-carbamoylthienyl-C-(3′-carboxy-2′-hydroxyphenylthiazolidin-4-one, LH3 (II. A MeOH solution of II reacts with Mn(II, Cu(II, Cd(II, Zr(OH2(IV, and UO2(VI ions and forms the coordination compounds, [Mn(LH(MeOH2], [Cu(LH]2, [Cd(LH], [Zr(OH2(OAc2(LH3], and [UO2(NO3(LH2(MeOH]. The compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, reflectance, and EPR studies and magnetic susceptibility measurements. LH3 behaves as a neutral tridentate ONS donor ligand in [Zr(OH2(OAc2(LH3], monobasic tridentate ONS donor ligand in [UO2(NO3(LH2(MeOH], dibasic tridentate OOS donor ligand in [Cu(LH]2 and dibasic tetradentate OONO donor ligand in [Mn(LH(MeOH2] and [Cd(LH]. [Cu(LH]2 is dimer, while all other compounds are monomers in diphenyl. A square-planar structure for [Cu(LH]2, a tetrahedral structure for [Cd(LH], an octahedral structure for [Mn(LH(MeOH2], a pentagonal-bipyramidal structure for [Zr(OH2(OAc2(LH3], and an eight-coordinate structure for [UO2(NO3(LH2(MeOH] are proposed. The ligand (II and its compounds show antibacterial activities towards E. coli. (Gram negative and S. aureus (Gram positive.

Human CD4 restores normal T cell development and function in mice deficient in murine CD4

OpenAIRE

1994-01-01

The ability of a human coreceptor to function in mice was investigated by generating human CD4 (hCD4)-expressing transgenic mice on a mouse CD4-deficient (mCD4-/-) background. From developing thymocyte to matured T lymphocyte functions, hCD4 was shown to be physiologically active. By examining the expansion and deletion of specific V beta T cell families in mutated mice with and without hCD4, it was found that hCD4 can participate in positive and negative selection. Mature hCD4 single positiv...

Low Dose Total Body Irradiation Combined With Recombinant CD19-Ligand × Soluble TRAIL Fusion Protein is Highly Effective Against Radiation-resistant B-precursor Acute Lymphoblastic Leukemia in Mice

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Fatih M. Uckun

2015-04-01

Full Text Available In high-risk remission B-precursor acute lymphoblastic leukemia (BPL patients, relapse rates have remained high post-hematopoietic stem cell transplantation (HSCT even after the use of very intensive total body irradiation (TBI-based conditioning regimens, especially in patients with a high “minimal residual disease” (MRD burden. New agents capable of killing radiation-resistant BPL cells and selectively augmenting their radiation sensitivity are therefore urgently needed. We report preclinical proof-of-principle that the potency of radiation therapy against BPL can be augmented by combining radiation with recombinant human CD19-Ligand × soluble TRAIL (“CD19L–sTRAIL” fusion protein. CD19L–sTRAIL consistently killed radiation-resistant primary leukemia cells from BPL patients as well as BPL xenograft cells and their leukemia-initiating in vivo clonogenic fraction. Low dose total body irradiation (TBI combined with CD19L–sTRAIL was highly effective against (1 xenografted CD19+ radiochemotherapy-resistant human BPL in NOD/SCID (NS mice challenged with an otherwise invariably fatal dose of xenograft cells derived from relapsed BPL patients as well as (2 radiation-resistant advanced stage CD19+ murine BPL with lymphomatous features in CD22ΔE12xBCR-ABL double transgenic mice. We hypothesize that the incorporation of CD19L–sTRAIL into the pre-transplant TBI regimens of patients with very high-risk BPL will improve their survival outcome after HSCT.

The role of CD154-CD40 versus CD28-B7 costimulatory pathways in regulating allogeneic Th1 and Th2 responses in vivo

DEFF Research Database (Denmark)

Kishimoto, K; Dong, V M; Issazadeh-Navikas, Shohreh

2000-01-01

We used signal transducer and activator of transcription 4 (STAT4) and STAT6 gene knockout (-/-) mice as recipients of fully mismatched cardiac allografts to study the role of T-cell costimulatory pathways in regulating allogeneic T-helper 1 (Th1) versus Th2 responses in vivo. STAT4(-/-) mice have...... impaired Th1 responses, whereas STAT6(-/-) mice do not generate normal Th2 responses. Cardiac allografts from C57BL/6 mice were transplanted into normal wild-type (WT), STAT4(-/-), and STAT6(-/-) BALB/c recipients. STAT4(-/-) and STAT6(-/-) mice rejected their grafts with the same tempo as untreated WT....... Furthermore, there was a similar differential effect of CD28-B7 versus CD154-CD40 blockade in inhibiting immune responses in animals immunized with ovalbumin and complete Freund's adjuvant. These novel data indicate that Th1 and Th2 cells are differentially regulated by CD28-B7 versus CD154-CD40 costimulation...

Heterogeneity of Human Neutrophil CD177 Expression Results from CD177P1 Pseudogene Conversion.

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Zuopeng Wu

2016-05-01

Full Text Available Most humans harbor both CD177neg and CD177pos neutrophils but 1-10% of people are CD177null, placing them at risk for formation of anti-neutrophil antibodies that can cause transfusion-related acute lung injury and neonatal alloimmune neutropenia. By deep sequencing the CD177 locus, we catalogued CD177 single nucleotide variants and identified a novel stop codon in CD177null individuals arising from a single base substitution in exon 7. This is not a mutation in CD177 itself, rather the CD177null phenotype arises when exon 7 of CD177 is supplied entirely by the CD177 pseudogene (CD177P1, which appears to have resulted from allelic gene conversion. In CD177 expressing individuals the CD177 locus contains both CD177P1 and CD177 sequences. The proportion of CD177hi neutrophils in the blood is a heritable trait. Abundance of CD177hi neutrophils correlates with homozygosity for CD177 reference allele, while heterozygosity for ectopic CD177P1 gene conversion correlates with increased CD177neg neutrophils, in which both CD177P1 partially incorporated allele and paired intact CD177 allele are transcribed. Human neutrophil heterogeneity for CD177 expression arises by ectopic allelic conversion. Resolution of the genetic basis of CD177null phenotype identifies a method for screening for individuals at risk of CD177 isoimmunisation.

Supramolecular architectures constructed using angular bipyridyl ligands

International Nuclear Information System (INIS)

Barnett, Sarah Ann

2003-01-01

This work details the synthesis and characterization of a series of coordination frameworks that are formed using bidentate angular N-donor ligands. Pyrimidine was reacted with metal(ll) nitrate salts. Reactions using Cd(NO 3 ) 2 receive particular focus and the analogous reactions using the linear ligand, pyrazine, were studied for comparison. In all cases, two-dimensional coordination networks were prepared. Structural diversity is observed for the Cd(ll) centres including metal-nitrate bridging. In contrast, first row transition metal nitrates form isostructural one-dimensional chains with only the bridging N-donor ligands generating polymeric propagation. The angular ligand, 2,4-bis(4-pyridyl)-1,3,5-triazine (dpt), was reacted with Cd(NO 3 ) 2 and Zn(NO 3 ) 2 . Whereas Zn(NO 3 ) 2 compounds exhibit solvent mediated polymorphism, a range of structures were obtained for the reactions with Cd(NO 3 ) 2 , including the first example of a doubly parallel interpenetrated 4.8 2 net. 4,7-phenanthroline, was reacted with various metal(ll) nitrates as well as cobalt(ll) and copper(ll) halides. The ability of 4,7-phenanthroline to act as both a N-donor ligand and a hydrogen bond acceptor has been discussed. Reactions of CuSCN with pyrimidine yield an unusual three-dimensional structure in which polymeric propagation is not a result of ligand bridging. The reaction of CuSCN with dpt yielded structural supramolecular isomers. (author)

Human Cytomegalovirus Encoded miR-US25-1-5p Attenuates CD147/EMMPRIN-Mediated Early Antiviral Response

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Jun Chen

2017-12-01

Full Text Available Cellular receptor-mediated signaling pathways play critical roles during the initial immune response to Human Cytomegalovirus (HCMV infection. However, the involvement of type-I transmembrane glycoprotein CD147/EMMPRIN (extracellular matrix metalloproteinase inducer in the antiviral response to HCMV infection is still unknown. Here, we demonstrated the specific knockdown of CD147 significantly decreased HCMV-induced activation of NF-κB and Interferon-beta (IFN-β, which contribute to the cellular antiviral responses. Next, we confirmed that HCMV-encoded miR-US25-1-5p could target the 3′ UTR (Untranslated Region of CD147 mRNA, and thus facilitate HCMV lytic propagation at a low multiplicity of infection (MOI. The expression and secretion of Cyclophilin A (sCyPA, as a ligand for CD147 and a proinflammatory cytokine, were up-regulated in response to HCMV stimuli. Finally, we confirmed that CD147 mediated HCMV-triggered antiviral signaling via the sCyPA-CD147-ERK (extracellular regulated protein kinases/NF-κB axis signaling pathway. These findings reveal an important HCMV mechanism for evading antiviral innate immunity through its encoded microRNA by targeting transmembrane glycoprotein CD147, and a potential cause of HCMV inflammatory disorders due to the secretion of proinflammatory cytokine CyPA.

CD40 dependent exacerbation of immune mediated hepatitis by hepatic CD11b+ Gr-1+ myeloid derived suppressor cells in tumor bearing mice

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Kapanadze, Tamar; Medina-Echeverz, José; Gamrekelashvili, Jaba; Weiss, Jonathan M.; Wiltrout, Robert H.; Kapoor, Veena; Hawk, Nga; Terabe, Masaki; Berzofsky, Jay A.; Manns, Michael P.; Wang, Ena; Marincola, Francesco M.; Korangy, Firouzeh; Greten, Tim F.

2015-01-01

Immunosuppressive CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC) accumulate in the livers of tumor-bearing mice. We studied hepatic MDSC in two murine models of immune mediated hepatitis. Unexpectedly, treatment of tumor bearing mice with Concanavalin A or α-Galactosylceramide resulted in increased ALT and AST serum levels in comparison to tumor free mice. Adoptive transfer of hepatic MDSC into naïve mice exacerbated Concanavalin A induced liver damage. Hepatic CD11b+Gr-1+ cells revealed a polarized pro-inflammatory gene signature after Concanavalin A treatment. An interferon gamma- dependent up-regulation of CD40 on hepatic CD11b+Gr-1+ cells along with an up-regulation of CD80, CD86, and CD1d after Concanavalin A treatment was observed. Concanavalin A treatment resulted in a loss of suppressor function by tumor-induced CD11b+Gr-1+ MDSC as well as enhanced reactive oxygen species-mediated hepatotoxicity. CD40 knockdown in hepatic MDSC led to increased arginase activity upon Concanavalin A treatment and lower ALT/AST serum levels. Finally, blockade of arginase activity in Cd40−/− tumor-induced myeloid cells resulted in exacerbation of hepatitis and increased reactive oxygen species production in vivo. Our findings indicate that in a setting of acute hepatitis, tumor-induced hepatic MDSC act as pro-inflammatory immune effector cells capable of killing hepatocytes in a CD40-dependent manner. PMID:25616156

Innate-like control of human iNKT cell autoreactivity via the hypervariable CDR3beta loop.

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Gediminas Matulis

2010-06-01

Full Text Available Invariant Natural Killer T cells (iNKT are a versatile lymphocyte subset with important roles in both host defense and immunological tolerance. They express a highly conserved TCR which mediates recognition of the non-polymorphic, lipid-binding molecule CD1d. The structure of human iNKT TCRs is unique in that only one of the six complementarity determining region (CDR loops, CDR3beta, is hypervariable. The role of this loop for iNKT biology has been controversial, and it is unresolved whether it contributes to iNKT TCR:CD1d binding or antigen selectivity. On the one hand, the CDR3beta loop is dispensable for iNKT TCR binding to CD1d molecules presenting the xenobiotic alpha-galactosylceramide ligand KRN7000, which elicits a strong functional response from mouse and human iNKT cells. However, a role for CDR3beta in the recognition of CD1d molecules presenting less potent ligands, such as self-lipids, is suggested by the clonal distribution of iNKT autoreactivity. We demonstrate that the human iNKT repertoire comprises subsets of greatly differing TCR affinity to CD1d, and that these differences relate to their autoreactive functions. These functionally different iNKT subsets segregate in their ability to bind CD1d-tetramers loaded with the partial agonist alpha-linked glycolipid antigen OCH and structurally different endogenous beta-glycosylceramides. Using surface plasmon resonance with recombinant iNKT TCRs and different ligand-CD1d complexes, we demonstrate that the CDR3beta sequence strongly impacts on the iNKT TCR affinity to CD1d, independent of the loaded CD1d ligand. Collectively our data reveal a crucial role for CDR3beta for the function of human iNKT cells by tuning the overall affinity of the iNKT TCR to CD1d. This mechanism is relatively independent of the bound CD1d ligand and thus forms the basis of an inherent, CDR3beta dependent functional hierarchy of human iNKT cells.

Rational assembly of Pb(II)/Cd(II)/Mn(II) coordination polymers based on flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Energy Technology Data Exchange (ETDEWEB)

Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Robbins, Julianne; Zhang, Z. John [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Yin, Hong-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Wang, Yu-Hua [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China)

2015-05-15

Six new coordination polymers, namely, [Pb(L)(H{sub 2}O)] (1), [Pb(L)(phen)] (2), [Pb{sub 2}(L){sub 2}(4,4′-bipy){sub 0.5}] (3), [Cd(L)(phen)] (4), [Cd(L)(4,4′-bipy)]·H{sub 2}O (5) and [Mn(L)(4,4′-bipy)]·H{sub 2}O (6) have been synthesized by the hydrothermal reaction of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) with Pb(II)/Cd(II)/Mn(II) in the presence of ancillary ligands 4,4′-bipyridine (4,4′-bipy) or 1,10-phenanthroline (phen). Complexes 1 and 4–6 exhibit 2-D structures, and complexes 2–3 display 3-D frameworks, of which L{sup 2−} ligands join metal ions to single-stranded helical chains of 1, 3–6 and double-stranded helical chains of 2. Complexes 2 and 3 also contain double-stranded Metal–O helices. Topology analysis reveals that complexes 1 and 4 both represent 4-connected sql net, 2 represents 6-connected pcu net, 3 exhibits a novel (3,12)-connected net, while 5 and 6 display (3,5)-connected gek1 net. The six complexes exhibit two kinds of inorganic–organic connectivities: I{sup 0}O{sup 2} for 1, 4–6, and I{sup 1}O{sup 2} for 2–3. The photoluminescent properties of 4–5 and the magnetic properties of 6 have been investigated. - Graphical abstract: Six new Pb(II)/Cd(II)/Mn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent and magnetic properties have been investigated. - Highlights: • Six novel M(II) coordination polymers with 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid and N-donor ligands. • Complexes 1–6 show diverse intriguing helical characters. • The luminescent properties of complexes 1–5 were investigated. • Complex 6 shows antiferromagnetic coupling.

Reduced CD5(+) CD24(hi) CD38(hi) and interleukin-10(+) regulatory B cells in active anti-neutrophil cytoplasmic autoantibody-associated vasculitis permit increased circulating autoantibodies.

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Aybar, L T; McGregor, J G; Hogan, S L; Hu, Y; Mendoza, C E; Brant, E J; Poulton, C J; Henderson, C D; Falk, R J; Bunch, D O

2015-05-01

Pathogenesis of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is B cell-dependent, although how particular B cell subsets modulate immunopathogenesis remains unknown. Although their phenotype remains controversial, regulatory B cells (Bregs ), play a role in immunological tolerance via interleukin (IL)-10. Putative CD19(+) CD24(hi) CD38(hi) and CD19(+) CD24(hi) CD27(+) Bregs were evaluated in addition to their CD5(+) subsets in 69 patients with ANCA-associated vasculitis (AAV). B cell IL-10 was verified by flow cytometry following culture with CD40 ligand and cytosine-phosphate-guanosine (CpG) DNA. Patients with active disease had decreased levels of CD5(+) CD24(hi) CD38(hi) B cells and IL-10(+) B cells compared to patients in remission and healthy controls (HCs). As IL-10(+) and CD5(+) CD24(hi) CD38(hi) B cells normalized in remission within an individual, ANCA titres decreased. The CD5(+) subset of CD24(hi) CD38(hi) B cells decreases in active disease and rebounds during remission similarly to IL-10-producing B cells. Moreover, CD5(+) B cells are enriched in the ability to produce IL-10 compared to CD5(neg) B cells. Together these results suggest that CD5 may identify functional IL-10-producing Bregs . The malfunction of Bregs during active disease due to reduced IL-10 expression may thus permit ANCA production. © 2014 British Society for Immunology.

CD147 (Basigin/Emmprin) identifies FoxP3+CD45RO+CTLA4+-activated human regulatory T cells.

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Solstad, Therese; Bains, Simer Jit; Landskron, Johannes; Aandahl, Einar Martin; Thiede, Bernd; Taskén, Kjetil; Torgersen, Knut Martin

2011-11-10

Human CD4(+)FoxP3(+) T cells are functionally and phenotypically heterogeneous providing plasticity to immune activation and regulation. To better understand the functional dynamics within this subset, we first used a combined strategy of subcellular fractionation and proteomics to describe differences at the protein level between highly purified human CD4(+)CD25(+) and CD4(+)CD25(-) T-cell populations. This identified a set of membrane proteins highly expressed on the cell surface of human regulatory T cells (Tregs), including CD71, CD95, CD147, and CD148. CD147 (Basigin or Emmprin) divided CD4(+)CD25(+) cells into distinct subsets. Furthermore, CD147, CD25, FoxP3, and in particular CTLA-4 expression correlated. Phenotypical and functional analyses suggested that CD147 marks the switch between resting (CD45RA(+)) and activated (CD45RO(+)) subsets within the FoxP3(+) T-cell population. Sorting of regulatory T cells into CD147(-) and CD147(+) populations demonstrated that CD147 identifies an activated and highly suppressive CD45RO(+) Treg subset. When analyzing CD4(+) T cells for their cytokine producing potential, CD147 levels grouped the FoxP3(+) subset into 3 categories with different ability to produce IL-2, TNF-α, IFN-γ, and IL-17. Together, this suggests that CD147 is a direct marker for activated Tregs within the CD4(+)FoxP3(+) subset and may provide means to manipulate cells important for immune homeostasis.

Macrophage-specific nanotechnology-driven CD163 overexpression in human macrophages results in an M2 phenotype under inflammatory conditions.

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Alvarado-Vazquez, Perla Abigail; Bernal, Laura; Paige, Candler A; Grosick, Rachel L; Moracho Vilrriales, Carolina; Ferreira, David Wilson; Ulecia-Morón, Cristina; Romero-Sandoval, E Alfonso

2017-08-01

M1 macrophages release proinflammatory factors during inflammation. They transit to an M2 phenotype and release anti-inflammatory factors to resolve inflammation. An imbalance in the transition from M1 to M2 phenotype in macrophages contributes to the development of persistent inflammation. CD163, a member of the scavenger receptor cysteine-rich family, is an M2 macrophage marker. The functional role of CD163 during the resolution of inflammation is not completely known. We postulate that CD163 contributes to the transition from M1 to M2 phenotype in macrophages. We induced CD163 gene in THP-1 and primary human macrophages using polyethylenimine nanoparticles grafted with a mannose ligand (Man-PEI). This nanoparticle specifically targets cells of monocytic origin via mannose receptors. Cells were challenged with a single or a double stimulation of lipopolysaccharide (LPS). A CD163 or empty plasmid was complexed with Man-PEI nanoparticles for cell transfections. Quantitative RT-PCR, immunocytochemistry, and ELISAs were used for molecular assessments. CD163-overexpressing macrophages displayed reduced levels of tumor necrosis factor-alpha (TNF)-α and monocytes chemoattractant protein (MCP)-1 after a single stimulation with LPS. Following a double stimulation paradigm, CD163-overexpressing macrophages showed an increase of interleukin (IL)-10 and IL-1ra and a reduction of MCP-1. This anti-inflammatory phenotype was partially blocked by an anti-CD163 antibody (effects on IL-10 and IL-1ra). A decrease in the release of TNF-α, IL-1β, and IL-6 was observed in CD163-overexpressing human primary macrophages. The release of IL-6 was blocked by an anti-CD163 antibody in the CD163-overexpressing group. Our data show that the induction of the CD163 gene in human macrophages under inflammatory conditions produces changes in cytokine secretion in favor of an anti-inflammatory phenotype. Targeting macrophages to induce CD163 using cell-directed nanotechnology is an attractive

CD103 is a marker for alloantigen-induced regulatory CD8+ T cells

NARCIS (Netherlands)

Uss, Elena; Rowshani, Ajda T.; Hooibrink, Berend; Lardy, Neubury M.; van Lier, René A. W.; ten Berge, Ineke J. M.

2006-01-01

The alphaEbeta7 integrin CD103 may direct lymphocytes to its ligand E-cadherin. CD103 is expressed on T cells in lung and gut and on allograft-infiltrating T cells. Moreover, recent studies have documented expression of CD103 on CD4+ regulatory T cells. Approximately 4% of circulating CD8+ T cells

Cyclosporine-resistant, Rab27a-independent Mobilization of Intracellular Preformed CD40L Mediates Antigen-specific T Cell Help In Vitro

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Koguchi, Yoshinobu; Gardell, Jennifer L.; Thauland, Timothy J.; Parker, David C.

2011-01-01

CD40L is critically important for the initiation and maintenance of adaptive immune responses. It is generally thought that CD40L expression in CD4+ T cells is regulated transcriptionally and made from new mRNA following antigen recognition. However, recent studies with two-photon microscopy revealed that the majority of cognate interactions between effector CD4+ T cells and APCs are too short for de novo synthesis of CD40L. Given that effector and memory CD4+ T cells store preformed CD40L (pCD40L) in lysosomal compartments and that pCD40L comes to the cell surface within minutes of antigenic stimulation, we and others have proposed that pCD40L might mediate T cell-dependent activation of cognate APCs during brief encounters in vivo. However, it has not been shown that this relatively small amount of pCD40L is sufficient to activate APCs, owing to the difficulty of separating the effects of pCD40L from those of de novo CD40L and other cytokines in vitro. Here we show that pCD40L surface mobilization is resistant to cyclosporine or FK506 treatment, while de novo CD40L and cytokine expression are completely inhibited. These drugs thus provide a tool to dissect the role of pCD40L in APC activation. We find that pCD40L mediates selective activation of cognate but not bystander APCs in vitro and that mobilization of pCD40L does not depend on Rab27a, which is required for mobilization of lytic granules. Therefore, effector CD4+ T cells deliver pCD40L specifically to APCs on the same time scale as the lethal hit of CTLs but with distinct molecular machinery. PMID:21677130

Expression of CD40 is a positive prognostic factor of diffuse large B-cell lymphoma treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone

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Song G

2016-06-01

Full Text Available Guoqi Song,1 Huiyun Ni,1 Linqing Zou,2 Shukui Wang,3 Fuliang Tian,4 Hong Liu,1 William C Cho5 1Department of Hematology, Affiliated Hospital of Nantong University, Nantong, 2Department of Human Anatomy, Nantong University, Nantong, 3Central Laboratory of Nanjing First Hospital, Nanjing Medical University, Nanjing, 4Maternal and Child Health Hospital of Lianyungang, Lianyungang, Jiangsu, People’s Republic of China; 5Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong Objectives: The objective of this study was to investigate the expression level of CD40 and its role in the prognosis of patients with diffuse large B-cell lymphoma (DLBCL who were treated with rituximab-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone.Design and methods: The immunohistochemical expressions of CD40 in 186 well-characterized DLBCL patients were evaluated by tissue microarrays, thereby revealing the relationship of the molecule CD40 with known tumor, patient-related variables, and survival rates.Results: The results showed that CD40 expressions were not statistically different between the germinal center B-cell-like (GCB type and the non-GCB type. We also analyzed the relationships of CD40 expression with overall survival (OS and progression-free survival (PFS in DLBCL patients who were uniformly treated with R-CHOP. A low expression of CD40 compared to high expression is related to poor OS and PFS. Conclusion: Our findings indicate that the CD40 level at onset acts as an independent prognostic predictor of DLBCL patients treated with R-CHOP. Keywords: CD40, diffuse large B-cell lymphoma, R-CHOP, prognostic factor

Immunoexpression of CD30 and CD30 ligand in deciduas from spontaneous abortions

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M Trovato

2009-06-01

Full Text Available In the present study, using immunohistochemistry, we studied the expression of CD30 and CD30-L in 35 deciduas obtained from women following elective abortion during normal physiological gestation and in 60 deciduas obtained from women after spontaneous abortion with or without signs of inflammation. The main difference was noticed in the first trimester of gestation in which was found a decrease in CD30/CD30-L-positive decidual glandular and stromal cells in a greater number of cases of spontaneous abortions with respect to cases of physiological pregnancies (70% vs 50%, p<0.05. In addition, deciduas from spontaneous abortions with inflammation and without inflammation reacted similarly. The reduced expression of CD30 and CD30-L and their cellular pattern detected in the deciduas from spontaneous abortions suggest that the CD30/CD30-L system is crucial for preventing abortions in the first trimester. And furthermore, the distinctive expression of CD30/CD30- L in deciduas from physiological pregnancies may indicate that the CD30/CD30-L system exerts its main role in the first trimester.

CD73 expression identifies a subset of IgM+ antigen-experienced cells with memory attributes that is T cell and CD40 signalling dependent.

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D'Souza, Lucas; Gupta, Sneh Lata; Bal, Vineeta; Rath, Satyajit; George, Anna

2017-12-01

B-cell memory was long characterized as isotype-switched, somatically mutated and germinal centre (GC)-derived. However, it is now clear that the memory pool is a complex mixture that includes unswitched and unmutated cells. Further, expression of CD73, CD80 and CD273 has allowed the categorization of B-cell memory into multiple subsets, with combinatorial expression of the markers increasing with GC progression, isotype-switching and acquisition of somatic mutations. We have extended these findings to determine whether these markers can be used to identify IgM memory phenotypically as arising from T-dependent versus T-independent responses. We report that CD73 expression identifies a subset of antigen-experienced IgM + cells that share attributes of functional B-cell memory. This subset is reduced in the spleens of T-cell-deficient and CD40-deficient mice and in mixed marrow chimeras made with mutant and wild-type marrow, the proportion of CD73 + IgM memory is restored in the T-cell-deficient donor compartment but not in the CD40-deficient donor compartment, indicating that CD40 ligation is involved in its generation. We also report that CD40 signalling supports optimal expression of CD73 on splenic T cells and age-associated B cells (ABCs), but not on other immune cells such as neutrophils, marginal zone B cells, peritoneal cavity B-1 B cells and regulatory T and B cells. Our data indicate that in addition to promoting GC-associated memory generation during B-cell differentiation, CD40-signalling can influence the composition of the unswitched memory B-cell pool. They also raise the possibility that a fraction of ABCs may represent T-cell-dependent IgM memory. © 2017 John Wiley & Sons Ltd.

Site-Specific Gene Editing of Human Hematopoietic Stem Cells for X-Linked Hyper-IgM Syndrome

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Caroline Y. Kuo

2018-05-01

Full Text Available X-linked hyper-immunoglobulin M (hyper-IgM syndrome (XHIM is a primary immunodeficiency due to mutations in CD40 ligand that affect immunoglobulin class-switch recombination and somatic hypermutation. The disease is amenable to gene therapy using retroviral vectors, but dysregulated gene expression results in abnormal lymphoproliferation in mouse models, highlighting the need for alternative strategies. Here, we demonstrate the ability of both the transcription activator-like effector nuclease (TALEN and clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9 platforms to efficiently drive integration of a normal copy of the CD40L cDNA delivered by Adeno-Associated Virus. Site-specific insertion of the donor sequence downstream of the endogenous CD40L promoter maintained physiologic expression of CD40L while overriding all reported downstream mutations. High levels of gene modification were achieved in primary human hematopoietic stem cells (HSCs, as well as in cell lines and XHIM-patient-derived T cells. Notably, gene-corrected HSCs engrafted in immunodeficient mice at clinically relevant frequencies. These studies provide the foundation for a permanent curative therapy in XHIM.

Estimation of CD4+ and CD8+ T-lymphocytes in human immunodeficiency virus infection and acquired immunodeficiency syndrome patients in Manipur

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Singh H

2007-01-01

Full Text Available Purpose : To estimate and stratify CD4 + and CD8 + T-lymphocyte levels in human immunodeficiency virus (HIV infected (asymptomatic and acquired immunodeficiency syndrome (AIDS patients (symptomatic and correlate the clinical features of the patients with CD4+ and CD8+ lymphocyte level. Methods : Between April 2002 and September 2003, a total of 415 HIV seropositive adult patients (297 males and 118 females attending Regional Institute of Medical Sciences (RIMS hospitals were tested for CD4+ and CD8+ T-lymphocytes by fluorescent activated cell sorter (FACS counter (Becton Dickinson. Symptomatic patients were diagnosed as per NACO clinical case definition. Results : Ranges of 0-50, 51-100, 101-200, 201-300, 301-400, 401-500 and above 500 CD4+ T-lymphocyte per microlitre were seen in 68, 52, 101, 73, 47, 31 and 43 patients respectively whereas CD8+ T-lymphocyte ranges of 0-300, 301-600, 601-900, 901-1500, 1501-2000, 2001-3500 per microlitre were seen in 29, 84, 92, 145, 40 and 25 patients respectively. One hundred and fifty patients were asymptomatic and 265 were symptomatic. CD4/CD8 ratio in asymptomatics and symptomatics were 0.13-1.69 and 0.01-0.93 respectively. Tuberculosis and candidiasis occurred in CD4+ T-lymphocyte categories between 0-400 cells per mL in symptomatics. However, cryptosporidiosis, toxoplasmosis, herpes zoster, cryptococcal meningitis, Pneumocystis carinii pneumonia, penicilliosis and cytomegalovirus retinitis were seen in patients having CD4+ T-lymphocyte less than 200 per mL. Conclusions : CD4+ T-lymphocyte was decreased in both asymptomatic and symptomatic HIV patients, The decrease was greater in symptomatics while CD8+ T-lymphocyte was increased in both except advanced stage symptomatics. CD4:CD8 ratio was reversed in both groups. Opportunistic infections correlated with different CD4+ T-lymphocyte categories.

Production of multiple transgenic Yucatan miniature pigs expressing human complement regulatory factors, human CD55, CD59, and H-transferase genes.

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Young-Hee Jeong

Full Text Available The present study was conducted to generate transgenic pigs coexpressing human CD55, CD59, and H-transferase (HT using an IRES-mediated polycistronic vector. The study focused on hyperacute rejection (HAR when considering clinical xenotransplantation as an alternative source for human organ transplants. In total, 35 transgenic cloned piglets were produced by somatic cell nuclear transfer (SCNT and were confirmed for genomic integration of the transgenes from umbilical cord samples by PCR analysis. Eighteen swine umbilical vein endothelial cells (SUVEC were isolated from umbilical cord veins freshly obtained from the piglets. We observed a higher expression of transgenes in the transgenic SUVEC (Tg SUVEC compared with the human umbilical vein endothelial cells (HUVEC. Among these genes, HT and hCD59 were expressed at a higher level in the tested Tg organs compared with non-Tg control organs, but there was no difference in hCD55 expression between them. The transgenes in various organs of the Tg clones revealed organ-specific and spatial expression patterns. Using from 0 to 50% human serum solutions, we performed human complement-mediated cytolysis assays. The results showed that, overall, the Tg SUVEC tested had greater survival rates than did the non-Tg SUVEC, and the Tg SUVEC with higher HT expression levels tended to have more down-regulated α-Gal epitope expression, resulting in greater protection against cytotoxicity. By contrast, several Tg SUVEC with low CD55 expression exhibited a decreased resistance response to cytolysis. These results indicated that the levels of HT expression were inversely correlated with the levels of α-Gal epitope expression and that the combined expression of hCD55, hCD59, and HT proteins in SUVECs markedly enhances a protective response to human serum-mediated cytolysis. Taken together, these results suggest that combining a polycistronic vector system with SCNT methods provides a fast and efficient alternative

A human thymic epithelial cell culture system for the promotion of lymphopoiesis from hematopoietic stem cells.

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Beaudette-Zlatanova, Britte C; Knight, Katherine L; Zhang, Shubin; Stiff, Patrick J; Zúñiga-Pflücker, Juan Carlos; Le, Phong T

2011-05-01

A human thymic epithelial cell (TEC) line expressing human leukocyte antigen-ABC and human leukocyte antigen-DR was engineered to overexpress murine Delta-like 1 (TEC-Dl1) for the purpose of establishing a human culture system that supports T lymphopoiesis from hematopoietic progenitor cells (HPCs). Cord blood or bone marrow HPCs were co-cultured with either the parental TEC line expressing low levels of the Notch ligands, Delta-like 1 and Delta-like 4, or with TEC-Dl1 to determine if these cell lines support human lymphopoiesis. In co-cultures with cord blood or bone marrow HPCs, TEC-Dl1 cells promote de novo generation of CD7(pos)CD1a(pos) T-lineage committed cells. Most CD7(pos)CD1a(hi) cells are CD4(pos)CD8(pos) double-positive (DP). We found that TEC-Dl1 cells are insufficient to generate mature CD3(hi) CD4(pos) or CD3(hi) CD8(pos) single-positive (SP) T cells from the CD4(pos)CD8(pos) DP T cells; however, we detected CD3(lo) cells within the DP and SP CD4 and CD8 populations. The CD3(lo) SP cells expressed lower levels of interleukin-2Rα and interleukin-7Rα compared to CD3(lo) DP cells. In contrast to the TEC-Dl1 line, the parental TEC-84 line expressing low levels of human Notch ligands permits HPC differentiation to the B-cell lineage. We report for the first time a human TEC line that supports lymphopoiesis from cord blood and bone marrow HPC. The TEC cell lines described herein provide a novel human thymic stroma model to study the contribution of human leukocyte antigen molecules and Notch ligands to T-cell commitment and maturation and could be utilized to promote lymphopoiesis for immune cell therapy. Copyright © 2011 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

Structural Analysis Of CD59 Of Chinese Tree Shrew: A New Reference Molecule For Human Immune System Specific CD59 Drug Discovery.

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Panda, Subhamay; Kumari, Leena; Panda, Santamay

2017-11-17

Chinese tree shrews (Tupaia belangeri chinensis) bear several characteristics that are considered to be very crucial for utilizing in animal experimental models in biomedical research. Subsequent to the identification of key aspects and signaling pathways in nervous and immune systems, it is revealed that tree shrews acquires shared common as well as unique characteristics, and hence offers a genetic basis for employing this animal as a prospective model for biomedical research. CD59 glycoprotein, commonly referred to as MAC-inhibitory protein (MAC-IP), membrane inhibitor of reactive lysis (MIRL), or protectin, is encoded by the CD59 gene in human beings. It is the member of the LY6/uPAR/alpha-neurotoxin protein family. With this initial point the objective of this study was to determine a comparative composite based structure of CD59 of Chinese tree shrew. The additional objective of this study was to examine the distribution of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, hydrophobicity molecular surface analysis and electrostatic potential analysis with the assistance of several bioinformatical analytical tools. CD59 Amino acid sequence of Chinese tree shrew collected from the online database system of National Centre for Biotechnology Information. SignalP 4.0 online server was employed for detection of signal peptide instance within the protein sequence of CD59. Molecular model structure of CD59 protein was generated by the Iterative Threading ASSEmbly Refinement (I-TASSER) suite. The confirmation for three-dimensional structural model was evaluated by structure validation tools. Location of negatively and positively charged amino acid over molecular modeled structure, distribution of secondary structural elements, and hydrophobicity molecular surface analysis was performed with the help of Chimera tool. Electrostatic potential analysis was carried out with the adaptive Poisson

Structure of the extracellular portion of CD46 provides insights into its interactions with complement proteins and pathogens.

Directory of Open Access Journals (Sweden)

B David Persson

2010-09-01

Full Text Available The human membrane cofactor protein (MCP, CD46 is a central component of the innate immune system. CD46 protects autologous cells from complement attack by binding to complement proteins C3b and C4b and serving as a cofactor for their cleavage. Recent data show that CD46 also plays a role in mediating acquired immune responses, and in triggering autophagy. In addition to these physiologic functions, a significant number of pathogens, including select adenoviruses, measles virus, human herpes virus 6 (HHV-6, Streptococci, and Neisseria, use CD46 as a cell attachment receptor. We have determined the crystal structure of the extracellular region of CD46 in complex with the human adenovirus type 11 fiber knob. Extracellular CD46 comprises four short consensus repeats (SCR1-SCR4 that form an elongated structure resembling a hockey stick, with a long shaft and a short blade. Domains SCR1, SCR2 and SCR3 are arranged in a nearly linear fashion. Unexpectedly, however, the structure reveals a profound bend between domains SCR3 and SCR4, which has implications for the interactions with ligands as well as the orientation of the protein at the cell surface. This bend can be attributed to an insertion of five hydrophobic residues in a SCR3 surface loop. Residues in this loop have been implicated in interactions with complement, indicating that the bend participates in binding to C3b and C4b. The structure provides an accurate framework for mapping all known ligand binding sites onto the surface of CD46, thereby advancing an understanding of how CD46 acts as a receptor for pathogens and physiologic ligands of the immune system.

Human CD4+ T cells lyse target cells via granzyme/perforin upon circumvention of MHC class II restriction by an antibody-like immunoreceptor.

Science.gov (United States)

Hombach, Andreas; Köhler, Heike; Rappl, Gunter; Abken, Hinrich

2006-10-15

Immune elimination of tumor cells requires the close cooperation between CD8+ CTL and CD4+ Th cells. We circumvent MHC class II-restriction of CD4+ T cells by expression of a recombinant immunoreceptor with an Ab-derived binding domain redirecting specificity. Human CD4+ T cells grafted with an immunoreceptor specific for carcinoembryonic Ag (CEA) are activated to proliferate and secrete cytokines upon binding to CEA+ target cells. Notably, redirected CD4+ T cells mediate cytolysis of CEA+ tumor cells with high efficiencies. Lysis by redirected CD4+ T cells is independent of death receptor signaling via TNF-alpha or Fas, but mediated by perforin and granzyme because cytolysis is inhibited by blocking the release of cytotoxic granules, but not by blocking of Fas ligand or TNF-alpha. CD4+ T cells redirected by Ab-derived immunoreceptors in a MHC class II-independent fashion substantially extend the power of an adoptive, Ag-triggered immunotherapy not only by CD4+ T cell help, but also by cytolytic effector functions. Because cytolysis is predominantly mediated via granzyme/perforin, target cells that are resistant to death receptor signaling become sensitive to a cytolytic attack by engineered CD4+ T cells.

Glucocorticoid-induced TNF receptor family related protein ligand [GITR-L] is requisite for optimal functioning of regulatory CD4+ T cells.

Directory of Open Access Journals (Sweden)

Gongxian eLiao

2014-02-01

Full Text Available Glucocorticoid-Induced Tumor necrosis factor Receptor family-related protein (GITR, TNFRSF18, CD357 is constitutively expressed on regulatory T cells (Tregs and is inducible on effector T cells (Teffs. In this report, we examine the role of GITR-Ligand (GITR-L, which is expressed by antigen presenting cells, on the development and expansion of Tregs. We found that GITR-L is dispensable for the development of naturally occurring FoxP3+ Treg cells in the thymus. However, the expansion of Treg in GITR-L-/- mice is impaired after injection of the dendritic cells (DCs inducing factor Flt3 ligand. Furthermore, DCs from the liver of GITR-L-/- mice were less efficient in inducing proliferation of antigen-specific Treg cells in vitro than the same cells from WT littermates. Upon gene transfer of ovalbumin into hepatocytes of GITR-L-/- FoxP3(GFP reporter mice using adeno-associated virus (AAV8-OVA the number of antigen-specific Treg in liver and spleen is reduced. The reduced number of Tregs resulted in an increase in the number of ovalbumin specific CD8+ T effector cells. This is highly significant because proliferation of antigen specific CD8+ cells itself is dependent on the presence of GITR-L, as shown by in vitro experiments and by adoptive transfers into GITR-L-/-Rag-/- and Rag-/- mice that had received AAV8-OVA. Surprisingly, administering αCD3 significantly reduced the numbers of FoxP3+ Treg cells in the liver and spleen of GITR-L-/- but not WT mice. Because soluble Fc-GITR-L partially rescues αCD3 induced in vitro depletion of the CD103+ subset of FoxP3+CD4+ Treg cells, we conclude that expression of GITR-L by antigen presenting cells is requisite for optimal Treg-mediated regulation of immune responses including those in response during gene transfer.

Human Platelets Exhibit Chemotaxis using Functional N-Formyl Peptide Receptors

National Research Council Canada - National Science Library

Czapiga, Meggan; Gao, Ji-Liang; Kirk, Allen; Lekstrom-Himes, Julie

2005-01-01

Activated platelets participate in inflammatory and microbicidal processes by upregulation of surface selectins, shedding of CD40 ligand, and release of platelet microbicidal proteins and microparticles...

CD25 shedding by human natural occurring CD4+CD25+ regulatory T cells does not inhibit the action of IL-2

DEFF Research Database (Denmark)

Pedersen, Anders Elm; Lauritsen, Jens Peter Holst

2009-01-01

Tregs are known to inhibit CD4+ T cell in a contact-dependent manner, but at the same time, various suppressive factors are secreted. We, here, demonstrate that human naturally occurring CD4+CD25+ Tregs are able to shed large amounts of soluble CD25 upon activation. Secretion of sCD25 could add......Regulatory T (Treg) cells are important for the maintenance of peripheral tolerance and inhibition of pathogenic T-cell responses. Therefore, they are important for the limitation of chronic inflammation but can also be deleterious by e.g. limiting antitumour immune responses. Natural occurring...... to the inhibitory effect of Tregs as such secretion in other settings has been proposed to act as a sink for local IL-2. However, we here demonstrate that supernatant from human Tregs containing high concentration of sCD25 does not inhibit proliferation of CD4+CD25(-) T cells or inhibit the action of IL-2...

Refolding and characterization of the functional ligand-binding domain of human lectin-like oxidized LDL receptor.

Science.gov (United States)

Xie, Qiuhong; Matsunaga, Shigeru; Shi, Xiaohua; Ogawa, Setsuko; Niimi, Setsuko; Wen, Zhesheng; Tokuyasu, Ken; Machida, Sachiko

2003-11-01

Lectin-like oxidized low-density lipoprotein receptor (LOX-1), a type II membrane protein that can recognize a variety of structurally unrelated macromolecules, plays an important role in host defense and is implicated in atherogenesis. To understand the interaction between human LOX-1 and its ligands, in this study the functional C-type lectin-like domain (CTLD) of LOX-1 was reconstituted at high efficiency from inactive aggregates in Escherichia coli using a refolding technique based on an artificial chaperone. The CD spectra of the purified domain suggested that the domain has alpha-helical structure and the blue shift of Trp residues was observed on refolding of the domain. Like wild-type hLOX-1, the refolded CTLD domain was able to bind modified LDL. Thus, even though CTLD contains six Cys residues that form disulfide bonds, it recovered its specific binding ability on refolding. This suggests that the correct disulfide bonds in CTLD were formed by the artificial chaperone technique. Although the domain lacked N-glycosylation, it showed high affinity for its ligand in surface plasmon resonance experiments. Thus, unglycosylated CTLD is sufficient for binding modified LDL.

IL-10-produced by human transitional B-cells down-regulates CD86 expression on B-cells leading to inhibition of CD4+T-cell responses.

Science.gov (United States)

Nova-Lamperti, Estefania; Fanelli, Giorgia; Becker, Pablo D; Chana, Prabhjoat; Elgueta, Raul; Dodd, Philippa C; Lord, Graham M; Lombardi, Giovanna; Hernandez-Fuentes, Maria P

2016-01-22

A novel subset of human regulatory B-cells has recently been described. They arise from within the transitional B-cell subpopulation and are characterised by the production of IL-10. They appear to be of significant importance in regulating T-cell immunity in vivo. Despite this important function, the molecular mechanisms by which they control T-cell activation are incompletely defined. Here we show that transitional B-cells produced more IL-10 and expressed higher levels of IL-10 receptor after CD40 engagement compared to other B-cell subsets. Furthermore, under this stimulatory condition, CD86 expressed by transitional B-cells was down regulated and T-cell proliferation was reduced. We provide evidence to demonstrate that the down-regulation of CD86 expression by transitional B-cells was due to the autocrine effect of IL-10, which in turn leads to decreased T-cell proliferation and TNF-α production. This analysis was further extended to peripheral B-cells in kidney transplant recipients. We observed that B-cells from patients tolerant to the graft maintained higher IL-10 production after CD40 ligation, which correlates with lower CD86 expression compared to patients with chronic rejection. Hence, the results obtained in this study shed light on a new alternative mechanism by which transitional B-cells inhibit T-cell proliferation and cytokine production.

IL-10-produced by human transitional B-cells down-regulates CD86 expression on B-cells leading to inhibition of CD4+T-cell responses

Science.gov (United States)

Nova-Lamperti, Estefania; Fanelli, Giorgia; Becker, Pablo D.; Chana, Prabhjoat; Elgueta, Raul; Dodd, Philippa C.; Lord, Graham M.; Lombardi, Giovanna; Hernandez-Fuentes, Maria P.

2016-01-01

A novel subset of human regulatory B-cells has recently been described. They arise from within the transitional B-cell subpopulation and are characterised by the production of IL-10. They appear to be of significant importance in regulating T-cell immunity in vivo. Despite this important function, the molecular mechanisms by which they control T-cell activation are incompletely defined. Here we show that transitional B-cells produced more IL-10 and expressed higher levels of IL-10 receptor after CD40 engagement compared to other B-cell subsets. Furthermore, under this stimulatory condition, CD86 expressed by transitional B-cells was down regulated and T-cell proliferation was reduced. We provide evidence to demonstrate that the down-regulation of CD86 expression by transitional B-cells was due to the autocrine effect of IL-10, which in turn leads to decreased T-cell proliferation and TNF-α production. This analysis was further extended to peripheral B-cells in kidney transplant recipients. We observed that B-cells from patients tolerant to the graft maintained higher IL-10 production after CD40 ligation, which correlates with lower CD86 expression compared to patients with chronic rejection. Hence, the results obtained in this study shed light on a new alternative mechanism by which transitional B-cells inhibit T-cell proliferation and cytokine production. PMID:26795594

Thermodynamic fingerprints of ligand binding to human telomeric G-quadruplexes

OpenAIRE

Bon?ina, Matja?; Podlipnik, ?rtomir; Piantanida, Ivo; Eilmes, Julita; Teulade-Fichou, Marie-Paule; Vesnaver, Gorazd; Lah, Jurij

2015-01-01

Thermodynamic studies of ligand binding to human telomere (ht) DNA quadruplexes, as a rule, neglect the involvement of various ht-DNA conformations in the binding process. Therefore, the thermodynamic driving forces and the mechanisms of ht-DNA G-quadruplex-ligand recognition remain poorly understood. In this work we characterize thermodynamically and structurally binding of netropsin (Net), dibenzotetraaza[14]annulene derivatives (DP77, DP78), cationic porphyrin (TMPyP4) and two bisquinolini...

Quantum chemistry of the minimal CdSe clusters

Science.gov (United States)

Yang, Ping; Tretiak, Sergei; Masunov, Artëm E.; Ivanov, Sergei

2008-08-01

Colloidal quantum dots are semiconductor nanocrystals (NCs) which have stimulated a great deal of research and have attracted technical interest in recent years due to their chemical stability and the tunability of photophysical properties. While internal structure of large quantum dots is similar to bulk, their surface structure and passivating role of capping ligands (surfactants) are not fully understood to date. We apply ab initio wavefunction methods, density functional theory, and semiempirical approaches to study the passivation effects of substituted phosphine and amine ligands on the minimal cluster Cd2Se2, which is also used to benchmark different computational methods versus high level ab initio techniques. Full geometry optimization of Cd2Se2 at different theory levels and ligand coverage is used to understand the affinities of various ligands and the impact of ligands on cluster structure. Most possible bonding patterns between ligands and surface Cd/Se atoms are considered, including a ligand coordinated to Se atoms. The degree of passivation of Cd and Se atoms (one or two ligands attached to one atom) is also studied. The results suggest that B3LYP/LANL2DZ level of theory is appropriate for the system modeling, whereas frequently used semiempirical methods (such as AM1 and PM3) produce unphysical results. The use of hydrogen atom for modeling of the cluster passivating ligands is found to yield unphysical results as well. Hence, the surface termination of II-VI semiconductor NCs with hydrogen atoms often used in computational models should probably be avoided. Basis set superposition error, zero-point energy, and thermal corrections, as well as solvent effects simulated with polarized continuum model are found to produce minor variations on the ligand binding energies. The effects of Cd-Se complex structure on both the electronic band gap (highest occupied molecular orbital-lowest unoccupied molecular orbital energy difference) and ligand binding

A novel form of the membrane protein CD147 that contains an extra Ig-like domain and interacts homophilically

Directory of Open Access Journals (Sweden)

Brown Marion H

2003-11-01

Full Text Available Abstract Background CD147 is a broadly distributed integral membrane glycoprotein with two Ig-like domains implicated in a wide range of functions. It is associated at the cell surface with the monocarboxylate transporters MCT1 and 4 but interactions of the extracellular region have not been characterised. Results We report the characterisation of a form of CD147 with an additional membrane-distal Ig-like domain. In contrast to the two domain form, this three domain form of CD147 interacts homophilically. Surface plasmon resonance analysis using recombinant proteins showed that the interaction was of low affinity (KD ~ 40 μM and this is typical of many interactions between membrane proteins. cDNA for the 3 domain form are rare but have been identified in human and mouse retina. Conclusion The finding that the three domain form of CD147 has an extracellular ligand, that is it interacts homophilically, suggests this interaction may be important in aligning lactate transporters in the retina where lactate is an important metabolite.

The role of complement receptors type 1 (CR1, CD35) and 2 (CR2, CD21) in promoting C3 fragment deposition and membrane attack complex formation on normal peripheral human B cells

DEFF Research Database (Denmark)

Nielsen, Claus Henrik; Pedersen, Morten Løbner; Marquart, Hanne Vibeke Hansen

2002-01-01

Normal human B lymphocytes are known to activate the alternative pathway (AP) of complement, leading to C3-fragment deposition and membrane attack complex (MAC) formation. The process is mediated via complement receptor type 2 (CR2, CD21), with complement receptor type 1 (CR1, CD35) playing...... a subsidiary role. In this study, we examine the relative contributions of CR1 and CR2 to the deposition of C3 fragments and MAC on B lymphocytes under circumstances where all complement pathways are operational. C3-fragment deposition and MAC formation were assessed on human peripheral B lymphocytes...... in the presence of 30% autologous serum. Blocking the CR2 ligand-binding site with monoclonal antibody (mAb) FE8 resulted in significant reduction (37.9+/-11.9%) in C3-fragment deposition, whereas MAC formation was only marginally affected (12.1+/-22.2% reduction). Blocking the CR1 binding-site resulted...

Gamma-ray mutagenesis studies in a new human-hamster hybrid, A(L)CD59(+/-), which has two human chromosomes 11 but is hemizygous for the CD59 gene

Science.gov (United States)

Kraemer, S. M.; Vannais, D. B.; Kronenberg, A.; Ueno, A.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

2001-01-01

Kraemer, S. M., Vannais, D. B., Kronenberg, A., Ueno, A. and Waldren, C. A. Gamma-Ray Mutagenesis Studies in a New Human-Hamster Hybrid, A(L)CD59(+/-), which has Two Human Chromosomes 11 but is Hemizygous for the CD59 Gene. Radiat. Res. 156, 10-19 (2001).We have developed a human-CHO hybrid cell line, named A(L)CD59(+/-), which has two copies of human chromosome 11 but is hemizygous for the CD59 gene and the CD59 cell surface antigen that it encodes. Our previous studies used the A(L) and A(L)C hybrids that respectively contain one or two sets of CHO chromosomes plus a single copy of human chromosome 11. The CD59 gene at 11p13.5 and the CD59 antigen encoded by it are the principal markers used in our mutagenesis studies. The hybrid A(L)CD59(+/-) contains two copies of human chromosome 11, only one of which carries the CD59 gene. The incidence of CD59 (-) mutants (formerly called S1(-)) induced by (137)Cs gamma rays is about fivefold greater in A(L)CD59(+/-) cells than in A(L) cells. Evidence is presented that this increase in mutant yield is due to the increased induction of certain classes of large chromosomal mutations that are lethal to A(L) cells but are tolerated in the A(L)CD59(+/-) hybrid. In addition, significantly more of the CD59 (-) mutants induced by (137)Cs gamma rays in A(L)CD59(+/-) cells display chromosomal instability than in A(L) cells. On the other hand, the yield of gamma-ray-induced CD59 (-) mutants in A(L)CD59(+/-) cells is half that of the A(L)C hybrid, which also tolerates very large mutations but has only one copy of human chromosome 11. We interpret the difference in mutability as evidence that repair processes involving the homologous chromosomes 11 play a role in determining mutant yields. The A(L)CD59(+/-) hybrid provides a useful new tool for quantifying mutagenesis and shedding light on mechanisms of genetic instability and mutagenesis.

Lipopolysaccharide-Elicited TSLPR Expression Enriches a Functionally Discrete Subset of Human CD14+ CD1c+ Monocytes.

Science.gov (United States)

Borriello, Francesco; Iannone, Raffaella; Di Somma, Sarah; Vastolo, Viviana; Petrosino, Giuseppe; Visconte, Feliciano; Raia, Maddalena; Scalia, Giulia; Loffredo, Stefania; Varricchi, Gilda; Galdiero, Maria Rosaria; Granata, Francescopaolo; Del Vecchio, Luigi; Portella, Giuseppe; Marone, Gianni

2017-05-01

Thymic stromal lymphopoietin (TSLP) is a cytokine produced mainly by epithelial cells in response to inflammatory or microbial stimuli and binds to the TSLP receptor (TSLPR) complex, a heterodimer composed of TSLPR and IL-7 receptor α (CD127). TSLP activates multiple immune cell subsets expressing the TSLPR complex and plays a role in several models of disease. Although human monocytes express TSLPR and CD127 mRNAs in response to the TLR4 agonist LPS, their responsiveness to TSLP is poorly defined. We demonstrate that TSLP enhances human CD14 + monocyte CCL17 production in response to LPS and IL-4. Surprisingly, only a subset of CD14 + CD16 - monocytes, TSLPR + monocytes (TSLPR + mono), expresses TSLPR complex upon LPS stimulation in an NF-κB- and p38-dependent manner. Phenotypic, functional, and transcriptomic analysis revealed specific features of TSLPR + mono, including higher CCL17 and IL-10 production and increased expression of genes with important immune functions (i.e., GAS6 , ALOX15B , FCGR2B , LAIR1 ). Strikingly, TSLPR + mono express higher levels of the dendritic cell marker CD1c. This evidence led us to identify a subset of peripheral blood CD14 + CD1c + cells that expresses the highest levels of TSLPR upon LPS stimulation. The translational relevance of these findings is highlighted by the higher expression of TSLPR and CD127 mRNAs in monocytes isolated from patients with Gram-negative sepsis compared with healthy control subjects. Our results emphasize a phenotypic and functional heterogeneity in an apparently homogeneous population of human CD14 + CD16 - monocytes and prompt further ontogenetic and functional analysis of CD14 + CD1c + and LPS-activated CD14 + CD1c + TSLPR + mono. Copyright © 2017 by The American Association of Immunologists, Inc.

Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

International Nuclear Information System (INIS)

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei

2015-01-01

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H_2ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H_2hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd_2(2,6-ndc)_2(bpp)(DMF)]·2DMF (1) and [Cd_3(hmdb)_3(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

Conformational diversity of flexible ligand in metal-organic frameworks controlled by size-matching mixed ligands

Energy Technology Data Exchange (ETDEWEB)

Hua, Xiu-Ni; Qin, Lan; Yan, Xiao-Zhi; Yu, Lei; Xie, Yi-Xin; Han, Lei, E-mail: hanlei@nbu.edu.cn

2015-12-15

Hydrothermal reactions of N-auxiliary flexible exo-bidentate ligand 1,3-bis(4-pyridyl)propane (bpp) and carboxylates ligands naphthalene-2,6-dicarboxylic acid (2,6-H{sub 2}ndc) or 4,4′-(hydroxymethylene)dibenzoic acid (H{sub 2}hmdb), in the presence of cadmium(II) salts have given rise to two novel metal-organic frameworks based on flexible ligands (FL-MOFs), namely, [Cd{sub 2}(2,6-ndc){sub 2}(bpp)(DMF)]·2DMF (1) and [Cd{sub 3}(hmdb){sub 3}(bpp)]·2DMF·2EtOH (2) (DMF=N,N-Dimethylformamide). Single-crystal X-ray diffraction analyses revealed that compound 1 exhibits a three-dimensional self-penetrating 6-connected framework based on dinuclear cluster second building unit. Compound 2 displays an infinite three-dimensional ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster and V-shaped organic linkers. The flexible bpp ligand displays different conformations in 1 and 2, which are successfully controlled by size-matching mixed ligands during the self-assembly process. - Graphical abstract: Compound 1 exhibits a 3D self-penetrating 6-connected framework based on dinuclear cluster, and 2 displays an infinite 3D ‘Lucky Clover’ shape (2,10)-connected network based on the trinuclear cluster. The flexible 1,3-bis(4-pyridyl)propane ligand displays different conformations in 1 and 2, which successfully controlled by size-matching mixed ligands during the self-assembly process.

Altered phenotypic and functional characteristics of CD3+CD56+ NKT-like cells in human gastric cancer.

Science.gov (United States)

Peng, Liu-Sheng; Mao, Fang-Yuan; Zhao, Yong-Liang; Wang, Ting-Ting; Chen, Na; Zhang, Jin-Yu; Cheng, Ping; Li, Wen-Hua; Lv, Yi-Pin; Teng, Yong-Sheng; Guo, Gang; Luo, Ping; Chen, Weisan; Zou, Quan-Ming; Zhuang, Yuan

2016-08-23

CD3+CD56+ natural killer T (NKT)-like cells are a group of CD3+ T cells sharing characteristics of NK and T cells and constitute a major component of host anti-tumor immune response in human cancer. However, the nature, function and clinical relevance of CD3+CD56+ NKT-like cells in human gastric cancer (GC) remain unclear. In this study, we showed that the frequencies of CD3+CD56+NKT-like cells in GC tumors were significantly decreased and low levels of tumor-infiltrating CD3+CD56+ NKT-like cells were positively correlated with poor survival and disease progression. Most CD3+CD56+NKT-like cells in GC tumors were CD45RA-CD27+/- central/effector-memory cells with decreased activity and lower expression levels of CD69, NKG2D and DNAM-1 than those in non-tumor tissues. We further observed that tumor-infiltrating CD3+CD56+ NKT-like cells had impaired effector function as shown by decreased IFN-γ, TNF-α, granzyme B and Ki-67 expression. Moreover, in vitro studies showed that soluble factors released from GC tumors could induce the functional impairment of CD3+CD56+ NKT-like cells. Collectively, our data indicate that decreased tumor-infiltrating CD3+CD56+ NKT-like cells with impaired effector function are associated with tumor progression and poor survival of GC patients, which may contribute to immune escape of GC.

Studies of the polynuclear complexes of labile ligands of vitamin B1 and Zn(II), Cd(II) and Hg(II) with Fe(III)

International Nuclear Information System (INIS)

Ojo, J.O.

2003-01-01

The ligands (complex salts) of vitamin B/sub 1/ (H Vit.) and the chlorides of Zn, Cd and Hg with the general formula, [H Vit]/sup +2/ [MCl/sub 4/]/sup -2/ were prepared and their interactions with iron (III) investigated. It was found that the complex salts of Zn and Cd produced the dinuclear complexes and that of mercury produced a complex without the thiamine moiety. The possible reason for the absence of a Hg complex similar to those of Zn and Cd may be that large size of mercury ion. The complexes were characterized by elementary analyses, infrared and visible spectra, magnetic moment and conductivity measurements.(author)

Receptor activator NFkappaB-ligand and osteoprotegerin protein expression in human periapical cysts and granulomas.

Science.gov (United States)

Menezes, Renato; Bramante, Clóvis Monteiro; da Silva Paiva, Katiúcia Batista; Letra, Ariadne; Carneiro, Everdan; Fernando Zambuzzi, Willian; Granjeiro, José Mauro

2006-09-01

The purpose of this study was to determine the expression of receptor activator of NFkappaB ligand (RANKL) and osteoprotegerin (OPG) associated with bone destruction in periapical cysts and granulomas. Forty human dental chronic periapical lesions were collected after periapical surgery. The lesions collected were fixed in 10% buffered formalin and histologically processed. At least 2 sections of each specimen were stained with hematoxylin and eosin for microscopic diagnosis. After that, 10 human periapical granulomas and 10 cysts were selected for immunohistochemical analysis for RANKL, OPG, and CD68+. Polymorphonuclear neutrophils, macrophages, endothelial cells, and lymphocytes were stained for RANKL and OPG in both lesions. Epithelial cells were also stained for RANKL and OPG in periapical cysts. Quantitative analysis was conducted and the results were expressed as a ratio of the number of immunostained cells over the total number of cells in the field (n = 100). The ratio of RANKL+/total cells was higher than OPG+/total cells in periapical granulomas (0.553 +/- 0.153 and 0.483 +/- 0.189, respectively; P cysts (0.519 +/- 0.09 and 0.339 +/- 0.117, respectively; P cysts. However, the ratio RANKL+/OPG+ in granulomas (1.336 +/- 0.723) and cysts (1.404 +/- 0.385) was not significantly different. The ratio of CD68+/total cells was significantly higher in granulomas (0.381 +/- 0.040) than in cysts (0.307 +/- 0.068) (P cysts and granulomas, strongly suggesting the involvement of these gene products in the development of periapical lesions.

Activation of human CD141+ and CD1c+ dendritic cells in vivo with combined TLR3 and TLR7/8 ligation.

Science.gov (United States)

Pearson, Frances E; Chang, Karshing; Minoda, Yoshihito; Rojas, Ingrid M Leal; Haigh, Oscar L; Daraj, Ghazal; Tullett, Kirsteen M; Radford, Kristen J

2018-04-01

Mice reconstituted with human hematopoietic stem cells are valuable models to study aspects of the human immune system in vivo. We describe a humanized mouse model (hu mice) in which fully functional human CD141 + and CD1c + myeloid and CD123 + plasmacytoid dendritic cells (DC) develop from human cord blood CD34 + cells in immunodeficient mice. CD141 + DC are the human equivalents of murine CD8 + /CD103 + DC which are essential for the induction of tumor-inhibitory cytotoxic T lymphocyte responses, making them attractive targets to exploit for the development of new cancer immunotherapies. We used CD34 + -engrafted NSG-A2 mice to investigate activation of DC subsets by synthetic dsRNA or ssRNA analogs polyinosinic-polycytidylic acid/poly I:C and Resiquimod/R848, agonists for TLR3 and TLR8, respectively, both of which are expressed by CD141 + DC. Injection of hu mice with these agonists resulted in upregulation of costimulatory molecules CD80, CD83 and CD86 by CD141 + and CD1c + DC alike, and their combination further enhanced expression of these molecules by both subsets. When combined, poly I:C and R848 enhanced serum levels of key cytokines associated with cross-presentation and the induction of cytotoxic T lymphocyte responses including IFN-α, IFN-β, IL-12 and CXCL10. These data advocate a combination of poly I:C and R848 TLR agonists as means of activating human DC for immunotherapy. © 2018 Australasian Society for Immunology Inc.

[Cloning of human CD45 gene and its expression in Hela cells].

Science.gov (United States)

Li, Jie; Xu, Tianyu; Wu, Lulin; Zhang, Liyun; Lu, Xiao; Zuo, Daming; Chen, Zhengliang

2015-11-01

To clone human CD45 gene PTPRC and establish Hela cells overexpressing recombinant human CD45 protein. The intact cDNA encoding human CD45 amplified using RT-PCR from the total RNA extracted from peripheral blood mononuclear cells (PBMCs) of a healthy donor was cloned into pMD-18T vector. The CD45 cDNA fragment amplified from the pMD-18T-CD45 by PCR was inserted to the coding region of the PcDNA3.1-3xflag vector, and the resultant recombinant expression vector PcDNA3.1-3xflag-CD45 was transfected into Hela cells. The expression of CD45 in Hela cells was detected by flow cytometry and Western blotting, and the phosphastase activity of CD45 was quantified using an alkaline phosphatase assay kit. The cDNA fragment of about 3 900 bp was amplified from human PBMCs and cloned into pMD-18T vector. The recombinant expression vector PcDNA3.1-3xflag-CD45 was constructed, whose restriction maps and sequence were consistent with those expected. The expression of CD45 in transfected Hela cells was detected by flow cytometry and Western blotting, and the expressed recombinant CD45 protein in Hela cells showed a phosphastase activity. The cDNA of human CD45 was successfully cloned and effectively expressed in Hela cells, which provides a basis for further exploration of the functions of CD45.

The role of CD40L, IL-10 and IL-17 in radioprotection

International Nuclear Information System (INIS)

Li Ting

2003-01-01

CD40L/CD40 interaction is central to the control of thymus-dependent humoral immunity and cell mediated immune responses. IL-17 has been shown to induce the production of IL-6 and G-CSF, which can induce proliferation and differentiation of CD34 + hematopoietic progenitors. IL-10 can interfere with up-regulation of costimulatory molecules, thus suppressing the production of costimulatory cytokines, such as IL-12. IL-10 has been implicated as an essential mediator in the induction of systemic immune suppression following ultraviolet (UV) exposure. Treating UV-irradiated mice with anti-IL-10 blocks the induction of immune suppression

Per a 10 protease activity modulates CD40 expression on dendritic cell surface by nuclear factor-kappaB pathway.

Science.gov (United States)

Goel, C; Kalra, N; Dwarakanath, B S; Gaur, S N; Arora, N

2015-05-01

Serine protease activity of Per a 10 from Periplaneta americana modulates dendritic cell (DC) functions by a mechanism(s) that remains unclear. In the present study, Per a 10 protease activity on CD40 expression and downstream signalling was evaluated in DCs. Monocyte-derived DCs from cockroach-allergic patients were treated with proteolytically active/heat-inactivated Per a 10. Stimulation with active Per a 10 demonstrated low CD40 expression on DCs surface (P Per a 10, suggesting cleavage of CD40. Per a 10 activity reduced the interleukin (IL)-12 and interferon (IFN)-γ secretion by DCs (P Per a 10, indicating that low CD40 expression is associated with low levels of IL-12 secretion. Active Per a 10 stimulation caused low nuclear factor-kappa B (NF-κB) activation in DCs compared to heat-inactivated Per a 10. Inhibition of the NF-κB pathway suppressed the CD40 expression and IL-12 secretion by DCs, further indicating that NF-κB is required for CD40 up-regulation. CD40 expression activated the tumour necrosis factor (TNF) receptor-associated factor 6 (TRAF6), thereby suggesting its involvement in NF-κB activation. Protease activity of Per a 10 induced p38 mitogen-activated protein kinase (MAPK) activation that showed no significant effect on CD40 expression by DCs. However, inhibiting p38 MAPK or NF-κB suppressed the secretion of IL-12, IFN-γ, IL-6 and TNF-α by DCs. Such DCs further reduced the secretion of IL-4, IL-6, IL-12 and TNF-α by CD4(+) T cells. In conclusion, protease activity of Per a 10 reduces CD40 expression on DCs. CD40 down-regulation leads to low NF-κB levels, thereby modulating DC-mediated immune responses. © 2014 British Society for Immunology.

Human influenza viruses and CD8(+) T cell responses.

Science.gov (United States)

Grant, Emma J; Quiñones-Parra, Sergio M; Clemens, E Bridie; Kedzierska, Katherine

2016-02-01

Influenza A viruses (IAVs) cause significant morbidity and mortality worldwide, despite new strain-specific vaccines being available annually. As IAV-specific CD8(+) T cells promote viral control in the absence of neutralizing antibodies, and can mediate cross-reactive immunity toward distinct IAVs to drive rapid recovery from both mild and severe influenza disease, there is great interest in developing a universal T cell vaccine. However, despite detailed studies in mouse models of influenza virus infection, there is still a paucity of data on human epitope-specific CD8(+) T cell responses to IAVs. This review focuses on our current understanding of human CD8(+) T cell immunity against distinct IAVs and discusses the possibility of achieving a CD8(+) T cell mediated-vaccine that protects against multiple, distinct IAV strains across diverse human populations. We also review the importance of CD8(+) T cell immunity in individuals highly susceptible to severe influenza infection, including those hospitalised with influenza, the elderly and Indigenous populations. Copyright © 2016 Elsevier B.V. All rights reserved.

CD83 Antibody Inhibits Human B Cell Responses to Antigen as well as Dendritic Cell-Mediated CD4 T Cell Responses.

Science.gov (United States)

Wong, Kuan Y; Baron, Rebecca; Seldon, Therese A; Jones, Martina L; Rice, Alison M; Munster, David J

2018-05-15

Anti-CD83 Ab capable of Ab-dependent cellular cytotoxicity can deplete activated CD83 + human dendritic cells, thereby inhibiting CD4 T cell-mediated acute graft-versus-host disease. As CD83 is also expressed on the surface of activated B lymphocytes, we hypothesized that anti-CD83 would also inhibit B cell responses to stimulation. We found that anti-CD83 inhibited total IgM and IgG production in vitro by allostimulated human PBMC. Also, Ag-specific Ab responses to immunization of SCID mice xenografted with human PBMC were inhibited by anti-CD83 treatment. This inhibition occurred without depletion of all human B cells because anti-CD83 lysed activated CD83 + B cells by Ab-dependent cellular cytotoxicity and spared resting (CD83 - ) B cells. In cultured human PBMC, anti-CD83 inhibited tetanus toxoid-stimulated B cell proliferation and concomitant dendritic cell-mediated CD4 T cell proliferation and expression of IFN-γ and IL-17A, with minimal losses of B cells (80% of B cells but had no effect on CD4 T cell proliferation and cytokine expression. By virtue of the ability of anti-CD83 to selectively deplete activated, but not resting, B cells and dendritic cells, with the latter reducing CD4 T cell responses, anti-CD83 may be clinically useful in autoimmunity and transplantation. Advantages might include inhibited expansion of autoantigen- or alloantigen-specific B cells and CD4 T cells, thus preventing further production of pathogenic Abs and inflammatory cytokines while preserving protective memory and regulatory cells. Copyright © 2018 by The American Association of Immunologists, Inc.

Suppression of FAT/CD36 mRNA by human growth hormone in pancreatic β-cells

DEFF Research Database (Denmark)

Dalgaard, Louise Torp; Thams, Peter Grevsen; Gaarn, Louise Winkel

2011-01-01

of this study was to examine the effect of human growth hormone (hGH) on mRNAs of fatty acid transport and binding proteins expressed in pancreatic β-cells, and to examine this in relation to β-cell survival after exposure to fatty acids. hGH decreased mRNA levels of FAT/CD36, whereas mRNAs of GPR40, FASN, FABP...

Suppression of FAT/CD36 mRNA by human growth hormone in pancreatic ß-cells

DEFF Research Database (Denmark)

Dalgaard, Louise Torp; Thams, Peter Grevsen; Gaarn, Louise Winkel

2011-01-01

of this study was to examine the effect of human growth hormone (hGH) on mRNAs of fatty acid transport and binding proteins expressed in pancreatic ß-cells, and to examine this in relation to ß-cell survival after exposure to fatty acids. hGH decreased mRNA levels of FAT/CD36, whereas mRNAs of GPR40, FASN, FABP...

Quantitation of species differences in albumin–ligand interactions for bovine, human and rat serum albumins using fluorescence spectroscopy: A test case with some Sudlow's site I ligands

International Nuclear Information System (INIS)

Poór, Miklós; Li, Yin; Matisz, Gergely; Kiss, László; Kunsági-Máté, Sándor; Kőszegi, Tamás

2014-01-01

Albumin, the most abundant plasma protein is an approximately 67 kDa sized water-soluble macromolecule. Since several drugs and xenobiotics circulate in the blood at least partially in albumin-bound form, albumin plays a key role in the pharmacokinetics/toxicokinetics of these chemicals. Most of the drugs and xenobiotics are Sudlow's site I ligands. In numerous studies, bovine serum albumin (BSA) is used for modeling albumin–ligand interactions and the results are extrapolated to human serum albumin (HSA). Furthermore, only limited information is available related to albumin–ligand interactions of different albumin species. Therefore, in our study, we have focused on the quantification of differences between bovine, human and rat serum albumin (RSA) using four Sudlow's site I ligands (luteolin, ochratoxin A, phenylbutazone and warfarin). Interactions were analyzed by fluorescence spectroscopy. Stability constants as well as competing capacities of the ligands were determined, and thermodynamic study was also performed. Our results highlight that there could be major differences between BSA, HSA and RSA in their ligand binding properties. Based on our observations we emphasize that in molecular aspects BSA behaves considerably differently from HSA or from albumins of other species therefore, it is strongly recommended to apply at least some confirmatory measurements when data obtained from other species are attempted to be extrapolated to HSA. -- Highlights: • Albumin–ligand interactions of human, bovine and rat albumins were studied. • Four Sudlow's site I ligands were tested by fluorescence spectroscopy. • Substantial differences were found in stability constants among albumin complexes. • Competing capacity of ligands showed major differences in the studied species. • Data obtained for BSA cannot be directly extrapolated to human albumin

Expression of CD44 splice variants in human primary brain tumors

NARCIS (Netherlands)

Kaaijk, P.; Troost, D.; Morsink, F.; Keehnen, R. M.; Leenstra, S.; Bosch, D. A.; Pals, S. T.

1995-01-01

Expression of CD44, particularly of certain splice variants, has been linked to tumor progression and metastatic potential in a number of different animal and human cancers. Although differential expression of CD44 standard epitopes (CD44s) in human brain tumors has been reported, the expression of

Secreted and transmembrane 1A is a novel co-stimulatory ligand.

Directory of Open Access Journals (Sweden)

Duncan Howie

Full Text Available Most T cell responses to pathogens or self antigens are modulated through the action of regulatory T cells and tissue-specific inhibitory mechanisms. To this end, several receptor-ligand pairs have evolved which either augment or diminish T cell function. Here we describe the tissue ligand SECTM1A (Secreted and transmembrane1A as an alternative murine CD7 ligand. We show that SECTM1A, like SECTM1B, binds strongly to CD7, and that SECTM1B was able to compete with SECTM1A for CD7 binding. SECTM1A is ubiquitously expressed and has two major alternative transcripts which differ in expression between tissues. Both immobilised soluble forms of SECTM1A and SECTM1B and cell surface anchored forms demonstrated opposing effects on CD4+ T cell activation. Whereas SECTM1A acted as a co-stimulator of T cells, enhancing IL-2 production and proliferation, SECTM1B proved inhibitory to TCR mediated T cell activation. Surprisingly, both functional outcomes proved to be CD7-independent, indicating the existence of alternative receptors for both ligands. We used a SECTM1A-Fc fusion protein to immunoprecipitate potential alternative ligands from detergent lysates of CD7(-/- T cells and, using mass spectrometry, identified GITR as a SECTM1A binder. SECTM1A was found to bind to activated CD4+ and CD8+ T cells as well as to CHO cells expressing cell surface GITR. Binding of SECTM1A to activated primary T cells was inhibited by either GITRL-Fc or anti GITR antibodies. Thus SECTM1A and SECTM1B represent novel reciprocal alternative ligands which may function to modulate the activation of effector and regulatory T cells. The ability of SECTM1A to activate T cells may be explained by its ability to bind to GITR.

Ligand-Modified Human Serum Albumin Nanoparticles for Enhanced Gene Delivery.

Science.gov (United States)

Look, Jennifer; Wilhelm, Nadine; von Briesen, Hagen; Noske, Nadja; Günther, Christine; Langer, Klaus; Gorjup, Erwin

2015-09-08

The development of nonviral gene delivery systems is a great challenge to enable safe gene therapy. In this study, ligand-modified nanoparticles based on human serum albumin (HSA) were developed and optimized for an efficient gene therapy. Different glutaraldehyde cross-linking degrees were investigated to optimize the HSA nanoparticles for gene delivery. The peptide sequence arginine-glycine-aspartate (RGD) and the HIV-1 transactivator of transduction sequence (Tat) are well-known as promising targeting ligands. Plasmid DNA loaded HSA nanoparticles were covalently modified on their surface with these different ligands. The transfection potential of the obtained plasmid DNA loaded RGD- and Tat-modified nanoparticles was investigated in vitro, and optimal incubation conditions for these preparations were studied. It turned out that Tat-modified HSA nanoparticles with the lowest cross-linking degree of 20% showed the highest transfection potential. Taken together, ligand-functionalized HSA nanoparticles represent promising tools for efficient and safe gene therapy.

Maturation of dendritic cells by recombinant human CD40L-trimer leads to a homogeneous cell population with enhanced surface marker expression and increased cytokine production

DEFF Research Database (Denmark)

Würtzen, P A; Nissen, Mogens Holst; Claesson, M H

2001-01-01

allostimulus or through the presentation of PPD, and influenza M1-peptide specific CTL activity was obtained with nonmaturated (CD83-) and maturated (CD83+) DC. In conclusion, a final maturation of monocyte-derived DC through huCD40LT resulted in a highly homogeneous cell population with enhanced surface...

Cd(II)-coordination polymers based on tetracarboxylic acid and diverse bis(imidazole) ligands: Synthesis, structural diversity and photoluminescence properties

Energy Technology Data Exchange (ETDEWEB)

Arıcı, Mürsel, E-mail: marici@ogu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Yeşilel, Okan Zafer [Department of Chemistry, Faculty of Arts and Sciences, Eskişehir Osmangazi University, 26480 Eskişehir (Turkey); Taş, Murat [Department of Science Education, Education Faculty, Ondokuz Mayıs University, 55139 Samsun (Turkey)

2017-01-15

Three new Cd(II)-coordination polymers, namely, ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,5-bipe){sub 2}]·2H{sub 2}O){sub n} (1), ([Cd{sub 2}(μ{sub 6}-ao{sub 2}btc)(μ-1,4-bix){sub 2}]{sub n}·2DMF) (2) and ([Cd{sub 2}(μ{sub 8}-abtc)(μ-1,4-betix)]·DMF·H{sub 2}O){sub n} (3) (ao{sub 2}btc=di-oxygenated form of 3,3′,5,5′-azobenzenetetracarboxylate, 1,5-bipe: 1,5-bis(imidazol-1yl)pentane, 1,4-bix=1,4-bis(imidazol-1ylmethyl)benzene, 1,4-betix=1,4-bis(2-ethylimidazol-1ylmethyl)benzene) were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi-flexible substituted bis(imidazole) linker was used, 3D framework of complex 3 was obtained with the paddlewheel Cd{sub 2}(CO{sub 2}){sub 4}-type binuclear SBU. Moreover, thermal and photoluminescence properties of the complexes were determined in detailed. - Graphical abstract: In this study, three novel Cd(II)-coordination polymers were synthesized with 3,3′,5,5′-azobenzenetetracarboxylic acid and flexible, semi-flexible and semi-flexible substituted bis(imidazole) linkers. They were characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction, powder X-ray diffractions (PXRD) and thermal analyses (TG/DTA). Complexes 1–3 exhibited structural diversities depending on flexible, semi-flexible and semi-flexible substituted bis(imidazole) ligands. Complex 1 was 2D structure with 3,6L18 topology. Complex 2 had a 3D pillar-layered framework with the rare sqc27 topology. When semi

TLR2 ligands induce NF-κB activation from endosomal compartments of human monocytes.

Directory of Open Access Journals (Sweden)

Karim J Brandt

Full Text Available Localization of Toll-like receptors (TLR in subcellular organelles is a major strategy to regulate innate immune responses. While TLR4, a cell-surface receptor, signals from both the plasma membrane and endosomal compartments, less is known about the functional role of endosomal trafficking upon TLR2 signaling. Here we show that the bacterial TLR2 ligands Pam3CSK4 and LTA activate NF-κB-dependent signaling from endosomal compartments in human monocytes and in a NF-κB sensitive reporter cell line, despite the expression of TLR2 at the cell surface. Further analyses indicate that TLR2-induced NF-κB activation is controlled by a clathrin/dynamin-dependent endocytosis mechanism, in which CD14 serves as an important upstream regulator. These findings establish that internalization of cell-surface TLR2 into endosomal compartments is required for NF-κB activation. These observations further demonstrate the need of endocytosis in the activation and regulation of TLR2-dependent signaling pathways.

Radiation-induced decrease of CD8+ dendritic cells contributes to Th1/Th2 shift.

Science.gov (United States)

Liu, Hu; Li, Bailong; Jia, Xiaojing; Ma, Yan; Gu, Yifeng; Zhang, Pei; Wei, Qun; Cai, Jianming; Cui, Jianguo; Gao, Fu; Yang, Yanyong

2017-05-01

Exposure to ionizing radiation (IR) often reduce the helper T (Th) 1 like function, resulting in a Th1/Th2 imbalance, which could affect the efficacy of cancer radiotherapy. As the most potent antigen presenting cells, dendritic cells (DC) can be divided into several subsets with specialized function. However, there is no literature covering the changes of DC subsets and their roles in immune regulation in response to IR. In the present study, we were aimed to investigate the changes of DC subsets after IR and its relationship with Th1/Th2 immunity. We found a significant decrease of BDCA3+DC in the blood of patients treated with radiotherapy. CD8+DC, a mouse equivalent of human BDCA3+DC, was also found decreased in mice spleen, peripheral blood and lymph node tissues after irradiation. As CD8+DC mainly induce Th1 immunity, we tested the changes of Th1/Th2 response and found that IR caused a repression of Th1 immunity, indicating a possible role of CD8+DC in radiation-induced Th1/Th2 imbalance. We also found that a CD8+DC-inducing cytokine, Fms-like tyrosine kinase 3 ligand (FLT3 ligand), restored CD8+DC and reversed Th1/Th2 shift. And then we found that bone marrow cells from irradiated mice differentiated into less CD8+DC, which was also protected by FLT3 ligand. In conclusion, our data showed that IR induced a decrease of CD8+DC and Th1/Th2 shift, which was reversed by Flt3 ligand treatment, suggesting a novel mechanism for radiation-induced immunosuppression. Copyright © 2017. Published by Elsevier B.V.

Interaction of cadmium with atrial natriuretic factor receptors: Ligand binding and cellular processing

International Nuclear Information System (INIS)

Giridhar, J.; Rathinavelu, A.; Isom, G.E.

1990-01-01

ANF is a peptide hormone secreted by the heart and produces potent diuresis and vascular smooth muscle relaxation. It is well known that Cd produces cardiovascular toxicity and is implicated in the pathogenesis of hypertension. Hence the effects of Cd on ANF receptor dynamics and ligand binding were studied in PC12 cells. Receptor internalization using 125 I-ANF as the ligand at 37 degree C displayed a decrease in endocytic rate constants (ERC) when either preincubated with Cd (500 μM for 30 min, ERC = 0.183/min) or coincubated with Cd (500 μM, ERC = 0.196) when compared to control value (ERC = 0.259/min). Ligand binding ( 125 I-ANF) was changed by Cd as reflected by a decrease in the number of binding sites/cell in both Cd preincubated (Kd = 3.81 x 10 -10 M, B max = 1 x 10 -10 M, binding sites/cell = 9333) and coincubated cells (Kd = 1.76 x 10 -10 M, B max = 3.92 x 10 -11 M, binding sites/cell = 5960) from control (Kd = 3.87 x 10 -10 M, B max = 9.58 x 10 -11 M, binding sites/cell = 12141). Photoaffinity labelling with 125 I-ANF as the ligand was used to measure receptor subtype binding. Coincubation of cells with Cd (500 μM) and ligand decreased both high and low mol. wt. receptor binding, whereas preincubation with Cd (500μM) for 60 min produced a slight decrease in binding of both receptor subtypes. These results indicate that the cardiovascular toxicity of Cd may be partially mediated by altered ANF receptor function

One ligand capable of in situ reaction in a mixed-ligand system with two new different frameworks

KAUST Repository

Wang, Xiaofang; Wang, Runwei; Liu, Xiaofang; Zhu, Pinwen; Qiu, Shilun

2017-01-01

The in situ ligand 2,3-pyrazinedicarboxylic acid (2,3-H2pzdc) mixed with 1,1′-(1,4-butanediyl)bis(benzimidazole) (bbbi) is used to form two coordination polymers ([Cd(2,3-pzdc)(bbbi)] (1) and [Cd2Cl3(2-pzc)(bbbi)2] (2)) under hydrothermal conditions

Chirality of TLR-2 ligand Pam3CysSK4 in fully synthetic peptide conjugates critically influences the induction of specific CD8+ T-cells.

Science.gov (United States)

Khan, Selina; Weterings, Jimmy J; Britten, Cedrik M; de Jong, Ana R; Graafland, Dirk; Melief, Cornelis J M; van der Burg, Sjoerd H; van der Marel, Gijs; Overkleeft, Hermen S; Filippov, Dmitri V; Ossendorp, Ferry

2009-03-01

Covalent conjugation of synthetic Toll-like receptor ligands (TLR-L) to synthetic antigenic peptides provides well-defined constructs that have significantly improved capacity to induce efficient priming of CD8(+) T lymphocytes in vivo. We have recently explored the cellular mechanisms underlying the efficient induction of a CD8(+) cytotoxic T lymphocyte response by such synthetic model vaccines [Khan, S., Bijker, M.S., Weterings, J.J., Tanke, H.J., Adema, G.J., van, H.T., Drijfhout, J.W., Melief, C.J., Overkleeft, H.S., van der Marel, G.A., Filippov, D.V., van der Burg, S.H., Ossendorp, F., 2007. Distinct uptake mechanisms but similar intracellular processing of two different toll-like receptor ligand-peptide conjugates in dendritic cells. J. Biol. Chem. 282, 21145-21159.]. In the current study we have investigated the behaviour of two diastereomers of the TLR-2 ligand Pam(3)CSK(4) (Pam) derivatives, namely the R- and S-epimers at C-2 of the glycerol moiety. Other studies have shown that the Pam(3)Cys based lipopeptides of R-configuration (Pam(R)) in the glycerol moiety enhanced macrophage and B-cell activation compared to those with S-configuration (Pam(S)). Here we report that Pam(R)-conjugates lead to better activation of dendritic cells than the Pam(S)-conjugates as judged by higher IL-12 secretion, upregulation of relevant markers for dendritic cell maturation. In contrast both epimers were internalized equally efficient in a clathrin-dependent manner indicating no qualitative difference in the uptake of the two stereoisomeric Pam-conjugates. We conclude that the enhanced DC activation is due to enhanced TLR-2 triggering by the Pam(R)-conjugate in contrast to the Pam(S)-conjugate. Importantly, induction of specific CD8(+) T-cells was significantly higher in mice injected with the Pam(R)-conjugates compared to mice injected with the Pam(S)-conjugate. In summary we show that the favourable effects of the Pam(R)-configuration of TLR-2 ligand can be attributed to

Chiral ligand-protected gold nanoclusters: Considering the optical activity from a viewpoint of ligand dissymmetric field

Directory of Open Access Journals (Sweden)

Hiroshi Yao

2016-10-01

Full Text Available Chirality is a geometric property of a physical, chemical, or biological object, which is not superimposable on its mirror image. Its significant presence has led to a strong demand in the development of chiral drugs, sensors, catalysts, and photofunctional materials. In recent years, chirality of nanoscale organic/inorganic hybrids has received tremendous attention owing to potential applications in chiral nanotechnology. In particular, with the recent progress in the syntheses and characterizations of atomically precise gold nanoclusters protected by achiral thiolates, atomic level origins of their chirality have been unveiled. On the other hand, chirality or optical activity in metal nanoclusters can also be introduced via the surface chiral ligands, which should be universal for the nanosystems. This tutorial review presents some optically-active metal (gold nanoclusters protected by chiral thiolates or phosphines, and their chiroptical (or circular dichroism; CD properties are discussed mostly from a viewpoint of the ligand dissymmetric field scheme. The examples are the gold nanoclusters protected by (R-/(S-2-phenylpropane-1-thiol, (R-/(S-mercaptosuccinic acid, phenylboronate-D/L-fructose complexes, phosphine sulfonate-ephedrinium ion pairs, or glutathione. Some methodologies for versatile asymmetric transformation and chiroptical controls of the nanocluster compounds are also described. In the dissymmetric field model as the origin of optical activity, the chiroptical responses of the gold nanoclusters are strongly associated with coupled oscillator and/or CD stealing mechanisms based on the concept of induced CD (ICD derived from a perturbation theory, so on this basis, some characteristic features of the observed CD responses of chiral ligand-protected gold nanoclusters are presented in detail. We believe that various kinds of origins of chirality found in ligand-protected gold nanoclusters may provide models for understanding those of

The role of metalloproteinase ADAM17 in regulating ICOS ligand-mediated humoral immune responses

DEFF Research Database (Denmark)

Marczynska, Joanna; Ozga, Aleksandra; Wlodarczyk, Agnieszka

2014-01-01

results in spleen and lymph node enlargement, as well as increased levels of Ag-specific class-switched Ig production following immunization with OVA together with anti-CD40 mAbs and polyinosinic-polycytidylic acid. Moreover, we demonstrate that the costimulatory ligand ICOS ligand (ICOSL) is selectively...... downregulated on the surface of B cells in an ADAM17-specific manner, although it is not proteolitically processed by recombinant ADAM17 in vitro. Finally, we show that higher cell surface levels of ICOSL in ADAM17(ex/ex) mice may contribute to the development of excessive Ab responses. Therefore, our data...... suggest a functional link between ADAM17 and ICOSL in controlling adaptive immune responses....

Parvovirus B19 integration into human CD36+ erythroid progenitor cells.

Science.gov (United States)

Janovitz, Tyler; Wong, Susan; Young, Neal S; Oliveira, Thiago; Falck-Pedersen, Erik

2017-11-01

The pathogenic autonomous human parvovirus B19 (B19V) productively infects erythroid progenitor cells (EPCs). Functional similarities between B19V nonstructural protein (NS1), a DNA binding endonuclease, and the Rep proteins of Adeno-Associated Virus (AAV) led us to hypothesize that NS1 may facilitate targeted nicking of the human genome and B19 vDNA integration. We adapted an integration capture sequencing protocol (IC-Seq) to screen B19V infected human CD36+ EPCs for viral integrants, and discovered 40,000 unique B19V integration events distributed throughout the human genome. Computational analysis of integration patterns revealed strong correlations with gene intronic regions, H3K9me3 sites, and the identification of 41 base pair consensus sequence with an octanucleotide core motif. The octanucleotide core has homology to a single region of B19V, adjacent to the P6 promoter TATA box. We present the first direct evidence that B19V infection of erythroid progenitor cells disrupts the human genome and facilitates viral DNA integration. Copyright © 2017 Elsevier Inc. All rights reserved.

CD80 and CD86 IgC domains are important for quaternary structure, receptor binding and co-signaling function.

Science.gov (United States)

Girard, Tanya; Gaucher, Denis; El-Far, Mohamed; Breton, Gaëlle; Sékaly, Rafick-Pierre

2014-09-01

CD86 and CD80, the ligands for the co-stimulatory molecules CD28 and CTLA-4, are members of the Ig superfamily. Their structure includes Ig variable-like (IgV) domains, Ig constant-like (IgC) domains and intracellular domains. Although crystallographic studies have clearly identified the IgV domain to be responsible for receptor interactions, earlier studies suggested that both Ig domains are required for full co-signaling function. Herein, we have used deletion and chimeric human CD80 and CD86 molecules in co-stimulation assays to study the impact of the multimeric state of IgV and IgC domains on receptor binding properties and on co-stimulatory function in a peptide-specific T cell activation model. We report for the first time the presence of CD80 dimers and CD86 monomers in living cells. Moreover, we show that the IgC domain of both molecules inhibits multimer formation and greatly affects binding to the co-receptors CD28 and CTLA-4. Finally, both IgC and intracellular domains are required for full co-signaling function. These findings reveal the distinct but complementary roles of CD80 and CD86 IgV and IgC domains in T cell activation. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification and Functional Characterization of Human Cd4+Cd25+ T Cells with Regulatory Properties Isolated from Peripheral Blood

Science.gov (United States)

Jonuleit, Helmut; Schmitt, Edgar; Stassen, Michael; Tuettenberg, Andrea; Knop, Jurgen; Enk, Alexander H.

2001-01-01

A subpopulation of peripheral human CD4+CD25+ T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte–associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4+CD25+ T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-4, or interferon (IFN)-γ on either protein or mRNA levels. The anergic state of CD4+CD25+ T cells is not reversible by the addition of anti-CD28, anti–CTLA-4, anti–transforming growth factor β, or anti–IL-10 antibody. However, the refractory state of CD4+CD25+ T cells was partially reversible by the addition of IL-2 or IL-4. These data demonstrate that human blood contains a resident T cell population with potent regulatory properties. PMID:11390435

Expression of Fas (CD95/APO-1) ligand by human breast cancers: significance for tumor immune privilege.

LENUS (Irish Health Repository)

O'Connell, J

2012-02-03

Breast cancers have been shown to elicit tumor-specific immune responses. As in other types of cancer, the antitumor immune response fails to contain breast tumor growth, and a reduction in both the quantity and cytotoxic effectiveness of tumor-infiltrating lymphocytes (TILs) is associated with a poorer prognosis. Fas ligand (FasL) induces apoptotic death of activated lymphocytes that express its cell surface receptor, FasR (CD95\\/APO-1). FasL-mediated apoptosis of activated lymphocytes contributes to normal immune downregulation through its roles in tolerance acquisition, immune response termination, and maintenance of immune privilege in the eye, testis, and fetus. In this report, we demonstrate that breast carcinomas express FasL. Using in situ hybridization and immunohistochemistry, we show that breast tumors constitutively express FasL at both the mRNA and protein levels, respectively. FasL expression is prevalent in breast cancer: 100% of breast tumors (17 of 17) were found to express FasL, and expression occurred over more than 50% of the tumor area in all cases. By immunohistochemistry, FasR was found to be coexpressed with FasL throughout large areas of all the breast tumors. This suggests that the tumor cells had acquired intracellular defects in FasL-mediated apoptotic signaling. FasL and FasR expression were independent of tumor type or infiltrative capacity. FasL expressed by tumor cells has previously been shown to kill Fas-sensitive lymphoid cells in vitro and has been associated with apoptosis of TILs in vivo. We conclude that mammary carcinomas express FasL in vivo as a potential inhibitor of the antitumor immune response.

Human CD5+ Innate Lymphoid Cells Are Functionally Immature and Their Development from CD34+ Progenitor Cells Is Regulated by Id2

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Maho Nagasawa

2017-08-01

Full Text Available Innate lymphoid cells (ILCs have emerged as a key cell type involved in surveillance and maintenance of mucosal tissues. Mouse ILCs rely on the transcriptional regulator Inhibitor of DNA-binding protein 2 (Id2 for their development. Here, we show that Id2 also drives development of human ILC because forced expression of Id2 in human thymic progenitors blocked T cell commitment, upregulated CD161 and promyelocytic leukemia zinc finger (PLZF, and maintained CD127 expression, markers that are characteristic for human ILCs. Surprisingly CD5 was also expressed on these in vitro generated ILCs. This was not an in vitro artifact because CD5 was also found on ex vivo isolated ILCs from thymus and from umbilical cord blood. CD5 was also expressed on small proportions of ILC2 and ILC3. CD5+ ILCs were functionally immature, but could further differentiate into mature CD5− cytokine-secreting ILCs. Our data show that Id2 governs human ILC development from thymic progenitor cells toward immature CD5+ ILCs.

CD40: Novel Association with Crohn's Disease and Replication in Multiple Sclerosis Susceptibility

Science.gov (United States)

Alcina, Antonio; Teruel, María; Díaz-Gallo, Lina M.; Gómez-García, María; López-Nevot, Miguel A.; Rodrigo, Luis; Nieto, Antonio; Cardeña, Carlos; Alcain, Guillermo; Díaz-Rubio, Manuel; de la Concha, Emilio G.; Fernandez, Oscar; Arroyo, Rafael

2010-01-01

Background A functional polymorphism located at −1 from the start codon of the CD40 gene, rs1883832, was previously reported to disrupt a Kozak sequence essential for translation. It has been consistently associated with Graves' disease risk in populations of different ethnicity and genetic proxies of this variant evaluated in genome-wide association studies have shown evidence of an effect in rheumatoid arthritis and multiple sclerosis (MS) susceptibility. However, the protective allele associated with Graves' disease or rheumatoid arthritis has shown a risk role in MS, an effect that we aimed to replicate in the present work. We hypothesized that this functional polymorphism might also show an association with other complex autoimmune condition such as inflammatory bowel disease, given the CD40 overexpression previously observed in Crohn's disease (CD) lesions. Methodology Genotyping of rs1883832C>T was performed in 1564 MS, 1102 CD and 969 ulcerative colitis (UC) Spanish patients and in 2948 ethnically matched controls by TaqMan chemistry. Principal Findings The observed effect of the minor allele rs1883832T was replicated in our independent Spanish MS cohort [p = 0.025; OR (95% CI) = 1.12 (1.01–1.23)]. The frequency of the minor allele was also significantly higher in CD patients than in controls [p = 0.002; OR (95% CI) = 1.19 (1.06–1.33)]. This increased predisposition was not detected in UC patients [p = 0.5; OR (95% CI) = 1.04 (0.93–1.17)]. Conclusion The impact of CD40 rs1883832 on MS and CD risk points to a common signaling shared by these autoimmune conditions. PMID:20634952

Modulation of phenotype and function of human CD4+CD25+ T regulatory lymphocytes mediated by cAMP elevating agents

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Antonella Riccomi

2016-09-01

Full Text Available We have shown that Cholera Toxin (CT and other cyclic AMP (cAMP elevating agents induce up-regulation of the inhibitory molecule CTLA-4 in human resting CD4+ T lymphocytes, which following the treatment acquired suppressive functions. In this study, we evaluated the effect of cAMP elevating agents on human CD4+CD25+ T cells, which include the T regulatory (Treg cells that play a pivotal role in the maintenance of immunological tolerance. We found that cAMP elevating agents induce up-regulation of CTLA-4 in CD4+CD25- and further enhance its expression in CD4+CD25+ T cells. We observed an increase of two isoforms of mRNA coding for the membrane and the soluble CTLA-4 molecules, suggesting that the regulation of CTLA-4 expression by cAMP is at the transcriptional level. In addition, we found that the increase of cAMP in CD4+CD25+ T cells converts the CD4+CD25+Foxp3- T cells in CD4+CD25+Foxp3+ T cells, whereas the increase of cAMP in CD4+CD25- T cells did not up-regulate Foxp3 in the absence of activation stimuli. To investigate the function of these cells, we performed an in vitro suppression assay by culturing CD4+CD25+ T cells untreated or pre-treated with CT with anti-CD3 mAbs-stimulated autologous PBMC. We found that CT enhances the inhibitory function of CD4+CD25+ T cells, CD4+ and CD8+ T cell proliferation and IFNγ production are strongly inhibited by CD4+CD25+ T cells pre-treated with cAMP elevating agents. Furthermore, we found that CD4+CD25+ T lymphocytes pre-treated with cAMP elevating agents induce the up-regulation of CD80 and CD86 co-stimulatory molecules on immature dendritic cells (DCs in the absence of antigenic stimulation, however without leading to full DC maturation. These data show that the increase of intracellular cAMP modulates the phenotype and function of human CD4+CD25+ T cells.

Spectroscopic study of cadmium (II) complexes with heterocyclic dithiocarbamate ligands

International Nuclear Information System (INIS)

Garcia-Fontan, S.; Rodriguez-Seoane, P.; Casas, J.S.; Sordo, J.; Jones, M.M.

1993-01-01

Cadmium(II) dithiocarbamates [Cd(dtc) 2 ] (dtc=4-carboxamidopiperidine-1-carbodithioate, morpholine-1-carbodithioate or 4-(2-hydroxyethyl)piperazine-1-carbodithioate) and [Cd(dtc) 2 ].H 2 O (dtc=4-hydroxypiperidine-1-carbodithioate} have been prepared and characterized by thermal analysis and IR and NMR ( 13 C, 113 Cd) spectrometry. Two of these ligands have previously been shown capable of removing cadmium from its aged in vivo storage sites. The use of solid state 13 C NMR measurements to establish the coordination mode of the dithiocarbomate ligands is also examined and the difficulties which arise are discussed. (orig.)

Prospectively Isolated Human Bone Marrow Cell-Derived MSCs Support Primitive Human CD34-Negative Hematopoietic Stem Cells.

Science.gov (United States)

Matsuoka, Yoshikazu; Nakatsuka, Ryusuke; Sumide, Keisuke; Kawamura, Hiroshi; Takahashi, Masaya; Fujioka, Tatsuya; Uemura, Yasushi; Asano, Hiroaki; Sasaki, Yutaka; Inoue, Masami; Ogawa, Hiroyasu; Takahashi, Takayuki; Hino, Masayuki; Sonoda, Yoshiaki

2015-05-01

Hematopoietic stem cells (HSCs) are maintained in a specialized bone marrow (BM) niche, which consists of osteoblasts, endothelial cells, and a variety of mesenchymal stem/stromal cells (MSCs). However, precisely what types of MSCs support human HSCs in the BM remain to be elucidated because of their heterogeneity. In this study, we succeeded in prospectively isolating/establishing three types of MSCs from human BM-derived lineage- and CD45-negative cells, according to their cell surface expression of CD271 and stage-specific embryonic antigen (SSEA)-4. Among them, the MSCs established from the Lineage(-) CD45(-) CD271(+) SSEA-4(+) fraction (DP MSC) could differentiate into osteoblasts and chondrocytes, but they lacked adipogenic differentiation potential. The DP MSCs expressed significantly higher levels of well-characterized HSC-supportive genes, including IGF-2, Wnt3a, Jagged1, TGFβ3, nestin, CXCL12, and Foxc1, compared with other MSCs. Interestingly, these osteo-chondrogenic DP MSCs possessed the ability to support cord blood-derived primitive human CD34-negative severe combined immunodeficiency-repopulating cells. The HSC-supportive actions of DP MSCs were partially carried out by soluble factors, including IGF-2, Wnt3a, and Jagged1. Moreover, contact between DP MSCs and CD34-positive (CD34(+) ) as well as CD34-negative (CD34(-) ) HSCs was important for the support/maintenance of the CD34(+/-) HSCs in vitro. These data suggest that DP MSCs might play an important role in the maintenance of human primitive HSCs in the BM niche. Therefore, the establishment of DP MSCs provides a new tool for the elucidation of the human HSC/niche interaction in vitro as well as in vivo. © 2014 AlphaMed Press.

Immune modulation through RNA interference-mediated silencing of CD40 in dendritic cells.

Science.gov (United States)

Karimi, Mohammad Hossein; Ebadi, Padideh; Pourfathollah, Ali Akbar; Soheili, Zahra Soheila; Samiee, Shahram; Ataee, Zahra; Tabei, Seyyed Ziyaoddin; Moazzeni, Seyed Mohammad

2009-01-01

RNA interference (RNAi) is an exciting mechanism for knocking down any target gene in transcriptional level. It is now clear that small interfering RNA (siRNA), a 19-21nt long dsRNA, can trigger a degradation process (RNAi) that specifically silences the expression of a cognate mRNA. Our findings in this study showed that down regulation of CD40 gene expression in dendritic cells (DCs) by RNAi culminated to immune modulation. Effective delivery of siRNA into DCs would be a reasonable method for the blocking of CD40 gene expression at the cell surface without any effect on other genes and cell cytotoxicity. The effects of siRNA against CD40 mRNA on the function and phenotype of DCs were investigated. The DCs were separated from the mice spleen and then cultured in vitro. By the means of Lipofectamine2000, siRNA was delivered to the cells and the efficacy of transfection was estimated by flow cytometry. By Annexine V and Propidium Iodide staining, we could evaluate the transfected cells viability. Also, the mRNA expression and protein synthesis were assessed by real-time PCR and flow cytometry, respectively. Knocking down the CD40 gene in the DCs caused an increase in IL-4 production, decrease in IL-12 production and allostimulation activity. All together, these effects would stimulate Th2 cytokines production from allogenic T-cells in vitro.

Quantitation of species differences in albumin–ligand interactions for bovine, human and rat serum albumins using fluorescence spectroscopy: A test case with some Sudlow's site I ligands

Energy Technology Data Exchange (ETDEWEB)

Poór, Miklós [Institute of Laboratory Medicine, University of Pécs, Ifjúság u. 13, Pécs H-7624 (Hungary); Li, Yin; Matisz, Gergely [Department of General and Physical Chemistry, University of Pécs, Pécs H-7624 (Hungary); János Szentágothai Research Center, Pécs H-7624 (Hungary); Kiss, László [Department of General and Physical Chemistry, University of Pécs, Pécs H-7624 (Hungary); Kunsági-Máté, Sándor [Department of General and Physical Chemistry, University of Pécs, Pécs H-7624 (Hungary); János Szentágothai Research Center, Pécs H-7624 (Hungary); Kőszegi, Tamás, E-mail: koszegit@freemail.hu [Institute of Laboratory Medicine, University of Pécs, Ifjúság u. 13, Pécs H-7624 (Hungary)

2014-01-15

Albumin, the most abundant plasma protein is an approximately 67 kDa sized water-soluble macromolecule. Since several drugs and xenobiotics circulate in the blood at least partially in albumin-bound form, albumin plays a key role in the pharmacokinetics/toxicokinetics of these chemicals. Most of the drugs and xenobiotics are Sudlow's site I ligands. In numerous studies, bovine serum albumin (BSA) is used for modeling albumin–ligand interactions and the results are extrapolated to human serum albumin (HSA). Furthermore, only limited information is available related to albumin–ligand interactions of different albumin species. Therefore, in our study, we have focused on the quantification of differences between bovine, human and rat serum albumin (RSA) using four Sudlow's site I ligands (luteolin, ochratoxin A, phenylbutazone and warfarin). Interactions were analyzed by fluorescence spectroscopy. Stability constants as well as competing capacities of the ligands were determined, and thermodynamic study was also performed. Our results highlight that there could be major differences between BSA, HSA and RSA in their ligand binding properties. Based on our observations we emphasize that in molecular aspects BSA behaves considerably differently from HSA or from albumins of other species therefore, it is strongly recommended to apply at least some confirmatory measurements when data obtained from other species are attempted to be extrapolated to HSA. -- Highlights: • Albumin–ligand interactions of human, bovine and rat albumins were studied. • Four Sudlow's site I ligands were tested by fluorescence spectroscopy. • Substantial differences were found in stability constants among albumin complexes. • Competing capacity of ligands showed major differences in the studied species. • Data obtained for BSA cannot be directly extrapolated to human albumin.

Effectiveness of slow-release systems in CD40 agonistic antibody immunotherapy of cancer

NARCIS (Netherlands)

Fransen, Marieke F.; Cordfunke, Robert A.; Sluijter, Marjolein; Van Steenbergen, Mies J.; Drijfhout, Jan W.; Ossendorp, Ferry; Hennink, Wim E.; Melief, Cornelis J M

2014-01-01

Slow-release delivery has great potential for specifically targeting immune-modulating agents into the tumor-draining area. In prior work we showed that local treatment of slowly delivered anti-CD40 antibody induced robust anti-tumor CD8+ T cell responses without systemic toxicity. We now report on

CD95 (FAS) and CD178 (FASL) induce the apoptosis of CD4+ and CD8+ cells isolated from the peripheral blood and spleen of dogs naturally infected with Leishmania spp.

Science.gov (United States)

Silva, Kathlenn Liezbeth Oliveira; Melo, Larissa Martins; Perosso, Juliana; Oliveira, Bruna Brito; Santos, Paulo Sérgio Patto Dos; Eugênio, Flávia de Rezende; Lima, Valéria Marçal Felix de

2013-11-08

Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion. Copyright © 2013 Elsevier B.V. All rights reserved.

Crystal structures and luminescence of two cadmium-carboxylate cluster-based compounds with mixed ligands

Energy Technology Data Exchange (ETDEWEB)

Ma, Hui-Fang; Lei, Qian; Wang, Yu-Ling; Yin, Shun-Gao; Liu, Qing-Yan [College of Chemistry and Chemical Engineering and Key Lab. of Functional Small Organic Molecule of Ministry of Education, Jiangxi Normal Univ., Nanchang (China)

2017-04-04

Reactions of Cd(NO{sub 3}){sub 2}.4H{sub 2}O with 2-quinolinecarboxylic acid (H-QLC) in the presence of 1,4-benzenedicarboxylic acid (H{sub 2}-BDC) or 1,3,5-benzenetricarboxylic acid (H-BTC) in DMF/H{sub 2}O solvent afforded two compounds, namely, [Cd(QLC)(BDC){sub 1/2}(H{sub 2}O)]{sub n} (1) and [Cd(QLC)(BTC){sub 1/3}]{sub n} (2). Both compounds are two-dimensional (2D) frameworks but feature different cadmium-carboxylate clusters as a result of the presence of the polycarboxylate ligands with different geometries and coordination preference. The dinuclear Cd{sub 2}(QLC){sub 2} units in 1 are bridged by the pairs of bridging water ligands to give a one-dimensional (1D) chain, which is further linked by the second ligand of BDC{sup 2-} to form a 2D structure. Compound 2 is constructed from unique hexanuclear macrometallacyclic Cd{sub 6}(QLC){sub 6} clusters, which are linked by the surrounding BTC{sup 3-} ligands to generate a 2D structure. Photoluminescence studies showed both compounds exhibit ligand-centered luminescent emissions with emission maxima at 405 and 401 nm, respectively. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Synthesis, Characterization and in Vitro Antibacterial Activities of CdO Nanoparticle and Nano-sheet Mixed-ligand of Cadmium(ІІ Complex

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Zohreh Rashidi Ranjbar

2016-07-01

Full Text Available Here, we report the synthesis of a Schiff-base mixed-ligand complex of cadmium(ІІ in bulk and nano-scales via the precipitation and sonochemical methods, respectively. The complex formula is [Cd(3-bpdh(3-bpdbCl2]n (1, where the ligands are 3-bpdh = 2,5-bis(3-pyridyl-3,4-diaza-2,4-hexadiene and 3-bpdb = 1,4-bis(3-pyridyl-2,3-diaza-1,3-butadiene. The structure of mixed-ligand complex (1 was characterized by IR, 1H NMR and elemental analyses. Cadmium(ІІ oxide nanoparticles were prepared by direct thermolysis from nanosheet of complex (1. The cadmium(ІІ oxide structure was characterized by X-ray Diffraction (XRD and Energy Dispersive X-ray  analyses (EDAX. Size, morphology and structural dispersion of all obtained nanostructures were characterized by Scanning Electron Microscopy (SEM. The Schiff-base ligands, bulk and nano-scales of complex (1 and cadmium(ІІ oxide nanoparticles were analyzed for antibacterial activities against Bacillus alvei (bacteria causing the honey bee European foulbrood disease. The Minimum Inhibitory Concentrations (MIC has been shown moderate antibacterial activities compared with some other standard drugs. Known antibiotics like penicillin and SXT (Trimethoprim/sulfamethoxazole were used as positive control.

Predominant CD4 T-lymphocyte tropism of human herpesvirus 6-related virus.

OpenAIRE

Takahashi, K; Sonoda, S; Higashi, K; Kondo, T; Takahashi, H; Takahashi, M; Yamanishi, K

1989-01-01

Human herpesvirus 6 (HHV-6)-related virus was isolated from CD4+ CD8- and CD3+ CD4+ mature T lymphocytes but could not be isolated from CD4- CD8+, CD4- CD8-, and CD3- T cells in the peripheral blood of exanthem subitum patients. HHV-6-related virus predominantly infected CD4+ CD8+, CD4+ CD8-, and CD3+ CD4+ cells with mature phenotypes and rarely infected CD4- CD8+ cells from cord blood mononuclear cells, which suggested predominant CD4 mature T-lymphocyte tropism of HHV-6-related virus.

Human natural killer cell maturation defect supports in vivo CD56(bright to CD56(dim lineage development.

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Carolina Inés Domaica

Full Text Available Two populations of human natural killer (NK cells can be identified in peripheral blood. The majority are CD3(-CD56(dim cells while the minority exhibits a CD3(-CD56(bright phenotype. In vitro evidence indicates that CD56(bright cells are precursors of CD56(dim cells, but in vivo evidence is lacking. Here, we studied NK cells from a patient that suffered from a melanoma and opportunistic fungal infection during childhood. The patient exhibited a stable phenotype characterized by a reduction in the frequency of peripheral blood CD3(-CD56(dim NK cells, accompanied by an overt increase in the frequency and absolute number of CD3(-CD56(bright cells. These NK cells exhibited similar expression of perforin, CD57 and CD158, the major activating receptors CD16, NKp46, NKG2D, DNAM-1, and 2B4, as well as the inhibitory receptor CD94/NKG2A, on both CD56(bright and CD56(dim NK cells as healthy controls. Also, both NK cell subpopulations produced IFN-γ upon stimulation with cytokines, and CD3(-CD56(dim NK cells degranulated in response to cytokines or K562 cells. However, upon stimulation with cytokines, a substantial fraction of CD56(dim cells failed to up-regulate CD57 and CD158, showed a reduction in the percentage of CD16(+ cells, and CD56(bright cells did not down-regulate CD62L, suggesting that CD56(dim cells could not acquire a terminally differentiated phenotype and that CD56(bright cells exhibit a maturation defect that might result in a potential altered migration pattern. These observations, support the notion that NK cells of this patient display a maturation/activation defect that precludes the generation of mature NK cells at a normal rate accompanied by CD56(dim NK cells that cannot completely acquire a terminally differentiated phenotype. Thus, our results provide evidence that support the concept that in vivo CD56(bright NK cells differentiate into CD56(dim NK cells, and contribute to further understand human NK cell ontogeny.

Tetraspanin CD9 modulates human lymphoma cellular proliferation via histone deacetylase activity

Energy Technology Data Exchange (ETDEWEB)

Herr, Michael J. [Vascular Biology Center of Excellence, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Molecular Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Surgery, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Longhurst, Celia M.; Baker, Benjamin [Vascular Biology Center of Excellence, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Homayouni, Ramin [Department of Biology, Bioinformatics Program, University of Memphis, Memphis, TN 38152 (United States); Speich, Henry E.; Kotha, Jayaprakash [Vascular Biology Center of Excellence, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Jennings, Lisa K., E-mail: ljennings@uthsc.edu [Vascular Biology Center of Excellence, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Molecular Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Surgery, The University of Tennessee Health Science Center, Memphis, TN 38163 (United States); Department of Biology, Bioinformatics Program, University of Memphis, Memphis, TN 38152 (United States)

2014-05-16

Highlights: • CD9 is differentially expressed in human Burkitt’s lymphoma cells. • We found that CD9 expression promotes these cells proliferation. • CD9 expression also increases HDAC activity. • HDAC inhibition decreased both cell proliferation and importantly CD9 expression. • CD9 may dictate HDAC efficacy and play a role in HDAC regulation. - Abstract: Non-Hodgkin Lymphoma (NHL) is a type of hematological malignancy that affects two percent of the overall population in the United States. Tetraspanin CD9 is a cell surface protein that has been thoroughly demonstrated to be a molecular facilitator of cellular phenotype. CD9 expression varies in two human lymphoma cell lines, Raji and BJAB. In this report, we investigated the functional relationship between CD9 and cell proliferation regulated by histone deacetylase (HDAC) activity in these two cell lines. Introduction of CD9 expression in Raji cells resulted in significantly increased cell proliferation and HDAC activity compared to Mock transfected Raji cells. The increase in CD9–Raji cell proliferation was significantly inhibited by HDAC inhibitor (HDACi) treatment. Pretreatment of BJAB cells with HDAC inhibitors resulted in a significant decrease in endogenous CD9 mRNA and cell surface expression. BJAB cells also displayed decreased cell proliferation after HDACi treatment. These results suggest a significant relationship between CD9 expression and cell proliferation in human lymphoma cells that may be modulated by HDAC activity.

Human haemato-endothelial precursors: cord blood CD34+ cells produce haemogenic endothelium.

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Elvira Pelosi

Full Text Available Embryologic and genetic evidence suggest a common origin of haematopoietic and endothelial lineages. In the murine embryo, recent studies indicate the presence of haemogenic endothelium and of a common haemato-endothelial precursor, the haemangioblast. Conversely, so far, little evidence supports the presence of haemogenic endothelium and haemangioblasts in later stages of development. Our studies indicate that human cord blood haematopoietic progenitors (CD34+45+144-, triggered by murine hepatocyte conditioned medium, differentiate into adherent proliferating endothelial precursors (CD144+CD105+CD146+CD31+CD45- capable of functioning as haemogenic endothelium. These cells, proven to give rise to functional vasculature in vivo, if further instructed by haematopoietic growth factors, first switch to transitional CD144+45+ cells and then to haematopoietic cells. These results highlight the plasticity of haemato-endhothelial precursors in human post-natal life. Furthermore, these studies may provide highly enriched populations of human post-fetal haemogenic endothelium, paving the way for innovative projects at a basic and possibly clinical level.

In situ depletion of CD4(+) T cells in human skin by Zanolimumab

DEFF Research Database (Denmark)

Villadsen, L.S.; Skov, L.; Dam, T.N.

2007-01-01

CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease......-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis......(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody...

The Tetraspanin CD151 in Papillomavirus Infection

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Konstanze D. Scheffer

2014-02-01

Full Text Available Human papillomaviruses (HPV are non-enveloped DNA tumor viruses that infect skin and mucosa. The most oncogenic subtype, HPV16, causes various types of cancer, including cervical, anal, and head and neck cancers. During the multistep process of infection, numerous host proteins are required for the delivery of virus genetic information into the nucleus of target cells. Over the last two decades, many host-cell proteins such as heparan sulfate proteoglycans, integrins, growth factor receptors, actin and the tetraspanin CD151 have been described to be involved in the process of infectious entry of HPV16. Tetraspanins have the ability to organize membrane microdomains and to directly influence the function of associated molecules, including binding of receptors to their ligands, receptor oligomerization and signal transduction. Here, we summarize the current knowledge on CD151, and CD151-associated partners during HPV infection and discuss the underlying mechanisms.

The human membrane cofactor CD46 is a receptor for species B adenovirus serotype 3.

Science.gov (United States)

Sirena, Dominique; Lilienfeld, Benjamin; Eisenhut, Markus; Kälin, Stefan; Boucke, Karin; Beerli, Roger R; Vogt, Lorenz; Ruedl, Christiane; Bachmann, Martin F; Greber, Urs F; Hemmi, Silvio

2004-05-01

Many human adenovirus (Ad) serotypes use the coxsackie B virus-Ad receptor (CAR). Recently, CD46 was suggested to be a receptor of species B Ad serotype 11 (Ad11), Ad14, Ad16, Ad21, Ad35, and Ad50. Using Sindbis virus-mediated cDNA library expression, we identify here the membrane cofactor protein CD46 as a surface receptor of species B Ad3. All four major CD46 transcripts and one minor CD46 transcript expressed in nucleated human cells were isolated. Rodent BHK cells stably expressing the BC1 form of CD46 bound radiolabeled Ad3 with a dissociation constant of 0.3 nM, identical to that of CD46-positive HeLa cells expressing twice as many Ad3 binding sites. Pull-down experiments with recombinant Ad3 fibers and a soluble form of the CD46 extracellular domain linked to the Fc portion of human immunoglobulin G (CD46ex-Fc) indicated direct interactions of the Ad3 fiber knob with CD46ex-Fc but not CARex-Fc (Fc-linked extracellular domain of CAR). Ad3 colocalized with cell surface CD46 in both rodent and human cells at the light and electron microscopy levels. Anti-CD46 antibodies and CD46ex-Fc inhibited Ad3 binding to CD46-expressing BHK cells more than 10-fold and to human cells 2-fold. In CD46-expressing BHK cells, wild-type Ad3 and a chimeric Ad consisting of the Ad5 capsid and the Ad3 fiber elicited dose-dependent cytopathic effects and transgene expression, albeit less efficiently than in human cells. Together, our results show that all of the major splice forms of CD46 are predominant and functional binding sites of Ad3 on CD46-expressing rodent and human cells but may not be the sole receptor of species B Ads on human cells. These results have implications for understanding viral pathogenesis and therapeutic gene delivery.

A one-dimensional cadmium(II complex supported by a sulfur–nitrogen mixed-donor ligand

Directory of Open Access Journals (Sweden)

Qian Gao

2009-07-01

Full Text Available In the title compound, catena-poly[cadmium(II-bis(μ-5-amino-1,3,4-thiadiazole-2-thiolato-κ2N3:S2;κ2S2:N3], [Cd(C2H2N3S22]n, the CdII ion is coordinated by two N atoms of the 1,3,4-thiadiazole rings from two ligands and two S atoms of sulfhydryl from two other ligands in a slightly distorted tetrahedral geometry. The ligands bridge CdII ions, forming one-dimensional chains along [001], which are connected by N—H...N and N—H...S hydrogen bonds into a three-dimensional network.

D2-40/podoplanin expression in the human placenta

Science.gov (United States)

Wang, Yuping; Sun, Jingxia; Gu, Yang; Zhao, Shuang; Groome, Lynn J.; Alexander, J. Steven

2011-01-01

Placental tissue expresses many lymphatic markers. The current study was undertaken to examine if D2-40/podoplanin, a lymphatic endothelial marker, was expressed in the human placentas, and how it is altered developmentally and pathologically. We studied D2-40/podoplanin and VEGFR-3 expressions in placentas from normotensive pregnancies at different gestational ages and in placentas from women with clinically defined preeclampsia. D2-40 expression in systemic lymphatic vessel endothelium served as a positive control. Protein expression for D2-40, VEGFR-3, and β-actin were determined by Western blot in placentas from normotensive (n=6) and preeclamptic (n=5) pregnancies. Our results show that D2-40/podoplanin was strongly expressed in the placenta, mainly as a network plexus pattern in the villous stroma throughout gestation. CD31 was limited to villous core fetal vessel endothelium and VEGFR-3 was found in both villous core fetal vessel endothelium and trophoblasts. D2-40/podoplanin expression was significantly decreased, and VEGFR-3 significantly increased in preeclamptic placental tissues compared to normotensive placental controls. Placental villous stroma is a reticular-like structure, and the localization of D2-40 to the stroma suggests that a lymphatic-like conductive network may exist in the human placenta. D2-40/podoplanin is an O-linked sialoglycoprotein. Although little is known regarding biological functions of sialylated glycoproteins within the placenta, placental D2-40/podoplanin may support fetal vessel angiogenesis during placenta development and reduced D2-40/podoplanin expression in preeclamptic placenta may contribute to altered interstitial fluid homeostasis and impaired angiogenesis in this pregnancy disorder. PMID:21095001

Polarographic study of mixed-ligand complexes of cadmium(II) with L-amino acid and vitamin B5

International Nuclear Information System (INIS)

Jain, Alok K.; Khan, Farid

1998-01-01

A survey of literature shows that ternary complexes of Cd II with L-amino acids and vitamin B 5 have not been studied so far. The present communication reports the formation of mixed-ligand complexes of Cd II with L-amino acids as primary ligands and vitamin B 5 as secondary ligand, studied by polarographic technique. (author)

Study the interaction between CdTe-glutathione and human serum albumin

International Nuclear Information System (INIS)

Yang, Qing; Zhou, Xi-min; Zhu, Yi-shuo; Chen, Xing-guo

2013-01-01

In this paper, glutathione (GSH) modified CdTe quantum dots (CdTe-GSH QDs) were synthesized in an aqueous solution. Then, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using the fluorescence spectroscopy. The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. The fluorescence data revealed that CdTe-GSH QDs could quench the intrinsic fluorescence of human serum albumin by a static quenching mechanism. Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. - Highlights: ► In this paper, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using a fluorescence spectroscopy. ► The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. ► Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. ► The research can help us assess biological toxicity of QDs and further expand the application scope of QDs.

Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d'Alene River, Idaho: Comparisons among chemical equilibrium models and implications for biotic ligand models

Science.gov (United States)

Balistrieri, L.S.; Blank, R.G.

2008-01-01

In order to evaluate thermodynamic speciation calculations inherent in biotic ligand models, the speciation of dissolved Cd, Cu, Pb, and Zn in aquatic systems influenced by historical mining activities is examined using equilibrium computer models and the diffusive gradients in thin films (DGT) technique. Several metal/organic-matter complexation models, including WHAM VI, NICA-Donnan, and Stockholm Humic model (SHM), are used in combination with inorganic speciation models to calculate the thermodynamic speciation of dissolved metals and concentrations of metal associated with biotic ligands (e.g., fish gills). Maximum dynamic metal concentrations, determined from total dissolved metal concentrations and thermodynamic speciation calculations, are compared with labile metal concentrations measured by DGT to assess which metal/organic-matter complexation model best describes metal speciation and, thereby, biotic ligand speciation, in the studied systems. Results indicate that the choice of model that defines metal/organic-matter interactions does not affect calculated concentrations of Cd and Zn associated with biotic ligands for geochemical conditions in the study area, whereas concentrations of Cu and Pb associated with biotic ligands depend on whether the speciation calculations use WHAM VI, NICA-Donnan, or SHM. Agreement between labile metal concentrations and dynamic metal concentrations occurs when WHAM VI is used to calculate Cu speciation and SHM is used to calculate Pb speciation. Additional work in systems that contain wide ranges in concentrations of multiple metals should incorporate analytical speciation methods, such as DGT, to constrain the speciation component of biotic ligand models. ?? 2008 Elsevier Ltd.

Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II, Cd(II, and Hg(II Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

Directory of Open Access Journals (Sweden)

Morteza Montazerozohori

2013-01-01

Full Text Available Synthesis of zinc(II/cadmium(II/mercury(II thiocyanate and azide complexes of a new bidentate Schiff-base ligand (L with general formula of MLX2 (M = Zn(II, Cd(II, and Hg(II in ethanol solution at room temperature is reported. The ligand and metal complexes were characterized by using ultraviolet-visible (UV-visible, Fourier transform infrared (FT-IR, 1H- and 13C-NMR spectroscopy and physical characterization, CHN analysis, and molar conductivity. 1H- and 13C-NMR spectra have been studied in DMSO-d6. The reasonable shifts of FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm well coordination of Schiff-base ligand and anions in an inner sphere coordination space. The conductivity measurements as well as spectral data indicated that the complexes are nonelectrolyte. Theoretical optimization on the structure of ligand and its complexes was performed at the Becke’s three-parameter hybrid functional (B3 with the nonlocal correlation of Lee-Yang-Parr (LYP level of theory with double-zeta valence (LANL2DZ basis set using GAUSSIAN 03 suite of program, and then some theoretical structural parameters such as bond lengths, bond angles, and torsion angles were obtained. Finally, electrochemical behavior of ligand and its complexes was investigated. Cyclic voltammograms of metal complexes showed considerable changes with respect to free ligand.

A viral long terminal repeat expressed in CD4+CD8+ precursors is downregulated in mature peripheral CD4-CD8+ or CD4+CD8- T cells.

OpenAIRE

Paquette, Y; Doyon, L; Laperrière, A; Hanna, Z; Ball, J; Sekaly, R P; Jolicoeur, P

1992-01-01

The long terminal repeat from a thymotropic mouse mammary tumor virus variant, DMBA-LV, was used to drive the expression of two reporter genes, murine c-myc and human CD4, in transgenic mice. Expression was observed specifically in thymic immature cells. Expression of c-myc in these cells induced oligoclonal CD4+ CD8+ T-cell thymomas. Expression of human CD4 was restricted to thymic progenitor CD4- CD8- and CD4+ CD8+ T cells and was shut off in mature CD4+ CD8- and CD4- CD8+ T cells, known to...

Adiponectin has a pivotal role in the cardioprotective effect of CP-3(iv), a selective CD36 azapeptide ligand, after transient coronary artery occlusion in mice.

Science.gov (United States)

Huynh, David N; Bessi, Valérie L; Ménard, Liliane; Piquereau, Jérôme; Proulx, Caroline; Febbraio, Maria; Lubell, William D; Carpentier, André C; Burelle, Yan; Ong, Huy; Marleau, Sylvie

2018-02-01

CD36 is a multiligand receptor involved in lipid metabolism. We investigated the mechanisms underlying the cardioprotective effect of CP-3(iv), an azapeptide belonging to a new class of selective CD36 ligands. The role of CP-3(iv) in mediating cardioprotection was investigated because CD36 signaling leads to activation of peroxisome proliferator-activated receptor-γ, a transcriptional regulator of adiponectin. CP-3(iv) pretreatment reduced infarct size by 54% and preserved hemodynamics in C57BL/6 mice subjected to 30 min coronary ligation and reperfusion but had no effect in CD36-deficient mice. The effects of CP-3(iv) were associated with an increase in circulating adiponectin levels, epididymal fat adiponectin gene expression, and adiponectin transcriptional regulators ( Pparg, Cebpb, Sirt1) after 6 h of reperfusion. Reduced myocardial oxidative stress and apoptosis were observed along with an increase in expression of myocardial adiponectin target proteins, including cyclooxygenase-2, phospho-AMPK, and phospho-Akt. Moreover, CP-3(iv) increased myocardial performance in isolated hearts, whereas blockade of adiponectin with an anti-adiponectin antibody abrogated it. CP-3(iv) exerts cardioprotection against myocardial ischemia and reperfusion (MI/R) injury and dysfunction, at least in part, by increasing circulating and myocardial adiponectin levels. Hence, both paracrine and endocrine effects of adiponectin may contribute to reduced reactive oxygen species generation and apoptosis after MI/R, in a CD36-dependent manner.-Huynh, D. N., Bessi, V. L., Ménard, L., Piquereau, J., Proulx, C., Febbraio, M., Lubell, W. D., Carpentier, A. C., Burelle, Y., Ong, H., Marleau, S. Adiponectin has a pivotal role in the cardioprotective effect of CP-3(iv), a selective CD36 azapeptide ligand, after transient coronary artery occlusion in mice.

CXCL10 is the key ligand for CXCR3 on CD8+ effector T cells involved in immune surveillance of the lymphocytic choriomeningitis virus-infected central nervous system

DEFF Research Database (Denmark)

Christensen, Jeanette Erbo; de Lemos, Carina; Moos, Torben

2006-01-01

/ligand pair is thought to play a central role in regulating T cell-mediated inflammation in this organ site. In this report, we investigated the role of CXCL10 in regulating CD8(+) T cell-mediated inflammation in the virus-infected brain. This was done through analysis of CXCL10-deficient mice infected...... indicate a central role for CXCL10 in regulating the accumulation of effector T cells at sites of CNS inflammation, with no apparent compensatory effect of other CXCR3 ligands....

Mixed ligand chelate therapy for plutonium and cadmium poisoning

Energy Technology Data Exchange (ETDEWEB)

Schubert, J; Derr, S K [Hope Coll., Holland, MI (USA)

1978-09-28

Some experiments with mice are described in which complete removal of tissue deposits of /sup 239/Pu and prevention of mortality in animals given lethal doses of Cd were achieved using a mixed ligand chelate treatment (MLC). The mixed ligand consisted of diethylenetriaminepentaacetic acid and salicylic acid.

CD56 marks human dendritic cell subsets with cytotoxic potential

NARCIS (Netherlands)

Roothans, D.; Smits, E.; Lion, E.; Tel, J.; Anguille, S.

2013-01-01

Human plasmacytoid and myeloid dendritic cells (DCs), when appropriately stimulated, can express the archetypal natural killer (NK)-cell surface marker CD56. In addition to classical DC functions, CD56(+) DCs are endowed with an unconventional cytotoxic capacity.

Low CD4/CD8 T-cell ratio associated with inflammatory arthropathy in human T-cell leukemia virus type I Tax transgenic mice.

Directory of Open Access Journals (Sweden)

Takeo Ohsugi

Full Text Available BACKGROUND: Human T-cell leukemia virus type I (HTLV-1 can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. A transgenic mouse that expresses HTLV-1 Tax also develops T-cell leukemia/lymphoma and an inflammatory arthropathy that resembles rheumatoid arthritis. The aim of this study was to identify the primary T-cell subsets involved in the development of arthropathy in Tax transgenic mice. PRINCIPAL FINDINGS: By 24 months of age, Tax transgenic mice developed severe arthropathy with a cumulative incidence of 22.8%. The pathological findings of arthropathy in Tax transgenic mice were similar to those seen in human rheumatoid arthritis or mouse models of rheumatoid arthritis, with synovial proliferation and a positive rheumatoid factor. Before the onset of spontaneous arthropathy, young and old Tax transgenic mice were not sensitive to collagen and did not develop arthritis after immunization with type II collagen. The arthropathic Tax transgenic mice showed a significantly decreased proportion of splenic CD4(+ T cells, whereas the proportion of splenic CD8(+ T cells was increased. Regulatory T cells (CD4(+CD25(+Foxp3(+ were significantly decreased and CD8(+ T cells that expressed the chemokine receptor CCR4 (CD8(+CCR4(+ were significantly increased in arthropathic Tax transgenic mice. The expression of tax mRNA was strong in the spleen and joints of arthropathic mice, with a 40-fold increase compared with healthy transgenic mice. CONCLUSIONS: Our findings reveal that Tax transgenic mice develop rheumatoid-like arthritis with proliferating synovial cells in the joints; however, the proportion of different splenic T-cell subsets in these mice was completely different from other commonly used animal models of rheumatoid arthritis. The crucial T-cell subsets in arthropathic Tax transgenic mice appear to resemble

Epitope-dependent mechanisms of CD27 neutralization revealed by X-ray crystallography

Energy Technology Data Exchange (ETDEWEB)

Obmolova, Galina; Teplyakov, Alexey; Malia, Thomas J.; Wunderler, Nicole; Kwok, Deborah; Barone, Linda; Sweet, Raymond; Ort, Tatiana; Scully, Michael; Gilliland, Gary L. (Janssen)

2017-03-01

CD27 is a T and B cell co-stimulatory protein of the TNF receptor superfamily dependent on the availability of the TNF-like ligand CD70. Two anti-CD27 neutralizing monoclonal antibodies were obtained from mouse hybridoma and subsequently humanized and optimized for binding the target. The two antibodies are similar in terms of their CD27-binding affinity and ability to block NF-κB signaling, however their clearance rates in monkeys are very different. The pharmacokinetics profiles could be epitope dependent. To identify the epitopes, we determined the crystal structure of the ternary complex between CD27 and the Fab fragments of these non-competing antibodies. The structure reveals the binding modes of the antibodies suggesting that their mechanisms of action are distinctly different and provides a possible explanation of the in vivo data.

Reactive glia promote development of CD103+ CD69+ CD8+ T-cells through programmed cell death-ligand 1 (PD-L1).

Science.gov (United States)

Prasad, Sujata; Hu, Shuxian; Sheng, Wen S; Chauhan, Priyanka; Lokensgard, James R

2018-06-01

Previous work from our laboratory has demonstrated in vivo persistence of CD103 + CD69 + brain resident memory CD8 + T-cells (bT RM ) following viral infection, and that the PD-1: PD-L1 pathway promotes development of these T RM cells within the brain. Although glial cells express low basal levels of PD-L1, its expression is upregulated upon IFN-γ-treatment, and they have been shown to modulate antiviral T-cell effector responses through the PD-1: PD-L1 pathway. We performed flow cytometric analysis of cells from co-cultures of mixed glia and CD8 + T-cells obtained from wild type mice to investigate the role of glial cells in the development of bT RM . In this study, we show that interactions between reactive glia and anti-CD3 Ab-stimulated CD8 + T-cells promote development of CD103 + CD69 + CD8 + T-cells through engagement of the PD-1: PD-L1 pathway. These studies used co-cultures of primary murine glial cells obtained from WT animals along with CD8 + T-cells obtained from either WT or PD-1 KO mice. We found that αCD3 Ab-stimulated CD8 + T-cells from WT animals increased expression of CD103 and CD69 when co-cultured with primary murine glial cells. In contrast, significantly reduced expression of CD103 and CD69 was observed using CD8 + T-cells from PD-1 KO mice. We also observed that reactive glia promoted high levels of CD127, a marker of memory precursor effector cells (MPEC), on CD69 + CD8 + T-cells, which promotes development of T RM cells. Interestingly, results obtained using T-cells from PD-1 KO animals showed significantly reduced expression of CD127 on CD69 + CD8 + cells. Additionally, blocking of glial PD-L1 resulted in decreased expression of CD103, along with reduced CD127 on CD69 + CD8 + T-cells. Taken together, these results demonstrate a role for activated glia in promoting development of bT RM through the PD-1: PD-L1 pathway. © 2018 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.

Cd(II) and Zn(II) thiocyanate coordination compounds with 3-ethylpyridine. Synthesis, crystal structures and properties

Energy Technology Data Exchange (ETDEWEB)

Neumann, Tristan; Jess, Inke; Dos Santos Cunha, Cesar; Terraschke, Huayna; Naether, Christian [Kiel Univ. (Germany). Inst. fuer Anorganische Chemie

2018-04-01

Reaction of Cd(NCS){sub 2} and Zn(NCS){sub 2} with 3-ethylpyridine leads to the formation of compounds of compositions M(NCS){sub 2}(3-ethylpyridine){sub 4} (M=Cd, 1-Cd; Zn, 1-Zn) and M(NCS){sub 2}(3-ethylpyridine){sub 2} (M=Cd, 2-Cd; Zn, 2-Zn). 1-Cd and 1-Zn are isotypic and form discrete complexes in which the metal cations are octahedrally coordinated by two trans-coordinating N-bonded thiocyanate anions and four 3-ethylpyridine co-ligands. In 2-Cd the cations are also octahedrally coordinated but linked into chains by pairs of μ-1,3-bridging anionic ligands. 2-Zn is built up of discrete complexes, in which the Zn cation is tetrahedrally coordinated by two N-bonded thiocyanate anions and two 3-ethylpyridine co-ligands. Compounds 1-Cd, 2-Cd and 2-Zn can be prepared in a pure state, whereas 1-Zn is unstable and transforms on storage into 2-Zn. If 1-Cd and 1-Zn are heated, a transformation into 2-Cd, respectively 2-Zn is observed. Luminescence measurements reveal that 1-Cd, 2-Cd and 2-Zn emit light in the blue spectral range with maxima at, respectively, 21724, 21654 and 22055 cm{sup -1}, assigned to ligand-based luminescence.

Humanized CD7 nanobody-based immunotoxins exhibit promising anti-T-cell acute lymphoblastic leukemia potential.

Science.gov (United States)

Yu, Yuan; Li, Jialu; Zhu, Xuejun; Tang, Xiaowen; Bao, Yangyi; Sun, Xiang; Huang, Yuhui; Tian, Fang; Liu, Xiaomei; Yang, Lin

2017-01-01

Nanobodies, named as VHHs (variable domain of heavy chain of HCAb [heavy-chain antibodies]), are derived from heavy-chain-only antibodies that circulate in sera of camelids. Their exceptional physicochemical properties, possibility of humanization, and unique antigen recognition properties make them excellent candidates for targeted delivery of biologically active components, including immunotoxins. In our previous efforts, we have successfully generated the monovalent and bivalent CD7 nanobody-based immunotoxins, which can effectively trigger the apoptosis of CD7-positive malignant cells. To pursue the possibility of translating those immunotoxins into clinics, we humanized the nanobody sequences (designated as dhuVHH6) as well as further truncated the Pseudomonas exotoxin A (PE)-derived PE38 toxin to produce a more protease-resistant form, which is named as PE-LR, by deleting majority of PE domain II. Three new types of immunotoxins, dhuVHH6-PE38, dVHH6-PE-LR, and dhuVHH6-PE-LR, were successfully constructed. These recombinant immunotoxins were expressed in Escherichia coli and showed that nanobody immunotoxins have the benefits of easy soluble expression in a prokaryotic expression system. Flow cytometry results revealed that all immunotoxins still maintained the ability to bind specifically to CD7-positive T lymphocyte strains without binding to CD7-negative control cells. Laser scanning confocal microscopy revealed that these proteins can be endocytosed into the cytoplasm after binding with CD7-positive cells and that this phenomenon was not observed in CD7-negative cells. WST-8 experiments showed that all immunotoxins retained the highly effective and specific growth inhibition activity in CD7-positive cell lines and primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Further in vivo animal model experiments showed that humanized dhuVHH6-PE38 immunotoxin can tolerate higher doses and extend the survival of NOD-Prkdc em26 Il2rg em26 Nju (NCG) mice

Anti-tumour therapeutic efficacy of OX40L in murine tumour model.

Science.gov (United States)

Ali, Selman A; Ahmad, Murrium; Lynam, June; McLean, Cornelia S; Entwisle, Claire; Loudon, Peter; Choolun, Esther; McArdle, Stephanie E B; Li, Geng; Mian, Shahid; Rees, Robert C

2004-09-09

OX40 ligand (OX40L), a member of TNF superfamily, is a co-stimulatory molecule involved in T cell activation. Systemic administration of mOX40L fusion protein significantly inhibited the growth of experimental lung metastasis and subcutaneous (s.c.) established colon (CT26) and breast (4T1) carcinomas. Vaccination with OX40L was significantly enhanced by combination treatment with intra-tumour injection of a disabled infectious single cycle-herpes simplex virus (DISC-HSV) vector encoding murine granulocyte macrophage-colony stimulating factor (mGM-CSF). Tumour rejection in response to OX40L therapy required functional CD4+ and CD8+ T cells and correlated with splenocyte cytotoxic T lymphocytes (CTLs) activity against the AH-1 gp70 peptide of the tumour associated antigen expressed by CT26 cells. These results demonstrate the potential role of the OX40L in cancer immunotherapy.

The influence of capping thioalkyl acid on the growth and photoluminescence efficiency of CdTe and CdSe quantum dots

International Nuclear Information System (INIS)

Aldeek, Fadi; Lambert, Jacques; Balan, Lavinia; Schneider, Raphael

2008-01-01

The influence of thioalkyl acid ligand was evaluated during aqueous synthesis at 100 deg. C and under hydrothermal conditions (150 deg. C) of CdTe and CdSe quantum dots (QDs). Experiments performed with 3-mercaptopropionic acid (MPA), 6-mercaptohexanoic acid (MHA) and 11-mercaptoundecanoic acid (MUA) demonstrated that the use of MHA and MUA allowed for the preparation of very small nanoparticles (0.6-2.5 nm) in carrying out the reaction under atmospheric pressure or in an autoclave and that the photophysical properties of QDs were dependent on the ligand and on the synthesis conditions. The influence of various experimental conditions, including the Te-to-Cd ratio, temperature, and precursor concentration, on the growth rate of CdTe or CdSe QDs has been systematically investigated. The fluorescence intensities of CdTe QDs capped with MPA, MHA, or MUA versus pH were also found to be related to the surface coverage of the nanoparticles.

Aging Impairs the Ability of Conventional Dendritic Cells to Cross-Prime CD8+ T Cells upon Stimulation with a TLR7 Ligand.

Directory of Open Access Journals (Sweden)

Estefanía R Zacca

Full Text Available The aging process is accompanied by altered immune system functioning and an increased risk of infection. Dendritic cells (DCs are antigen-presenting cells that play a key role in both adaptive and innate immunity, but how aging affects DCs and their influence on immunity has not been thoroughly established. Here we examined the function of conventional DCs (cDCs in old mice after TLR7 stimulation, focusing on their ability to cross-prime CD8+ T cells. Using polyU, a synthetic ssRNA analog, as TLR7 ligand and OVA as an antigen (Ag model, we found that cDCs from old mice have a poor ability to stimulate a CD8+ T cell-mediated cytotoxic response. cDCs from old mice exhibit alterations in Ag-processing machinery and TLR7 activation. Remarkably, CD8α+ cDCs from old mice have an impaired ability to activate naïve CD8+ T cells and, moreover, a lower capacity to mature and to process exogenous Ag. Taken together, our results suggest that immunosenescence impacts cDC function, affecting the activation of naïve CD8+ T cells and the generation of effector cytotoxic T cells.

Flt3 ligand-eGFP-reporter expression characterizes functionally distinct subpopulations of CD150+ long-term repopulating murine hematopoietic stem cells.

Science.gov (United States)

Tornack, Julia; Kawano, Yohei; Garbi, Natalio; Hämmerling, Günter J; Melchers, Fritz; Tsuneto, Motokazu

2017-09-01

The pool of hematopoietic stem cells (HSCs) in the bone marrow is a mixture of resting, proliferating, and differentiating cells. Long-term repopulating HSCs (LT-HSC) are routinely enriched as Lin - Sca1 + c-Kit + CD34 - Flt3 - CD150 + CD48 - cells. The Flt3 ligand (Flt3L) and its receptor Flt3 are important regulators of HSC maintenance, expansion and differentiation. Using Flt3L-eGFP reporter mice, we show that endogenous Flt3L-eGFP-reporter RNA expression correlates with eGFP-protein expression. This Flt3L-eGFP-reporter expression distinguishes two LT-HSC populations with differences in gene expressions and reconstituting potential. Thus, Flt3L-eGFP-reporter low cells are identified as predominantly resting HSCs with long-term repopulating capacities. In contrast, Flt3L-eGFP-reporter high cells are in majority proliferating HSCs with only short-term repopulating capacities. Flt3L-eGFP-reporter low cells express hypoxia, autophagy-inducing, and the LT-HSC-associated genes HoxB5 and Fgd5, while Flt3L-eGFP-reporter high HSCs upregulate genes involved in HSC differentiation. Flt3L-eGFP-reporter low cells develop to Flt3L-eGFP-reporter high cells in vitro, although Flt3L-eGFP-reporter high cells remain Flt3L-eGFP-reporter high . CD150 + Flt3L-eGFP-reporter low cells express either endothelial protein C receptor (EPCR) or CD41, while Flt3L-eGFP-reporter high cells do express EPCR but not CD41. Thus, FACS-enrichment of Flt3/ Flt3L-eGFP-reporter negative, Lin - CD150 + CD48 - EPCR + CD41 + HSCs allows a further 5-fold enrichment of functional LT-HSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Signaling signatures and functional properties of anti-human CD28 superagonistic antibodies.

Directory of Open Access Journals (Sweden)

Zoe Waibler

Full Text Available Superagonistic CD28 antibodies (CD28SAs activate T lymphocytes without concomitant perturbation of the TCR/CD3-complex. In rodents these reagents induce the preferential expansion of regulatory T cells and can be used for the treatment of autoimmune diseases. Unexpectedly, the humanized CD28 superagonist TGN1412 caused severe and life threatening adverse effects during a recently conducted phase I clinical trail. The underlying molecular mechanisms are as yet unclear. We show that TGN1412 as well as the commercially available CD28 superagonist ANC28.1 induce a delayed but extremely sustained calcium response in human naïve and memory CD4+ T cells but not in cynomolgus T lymphocytes. The sustained Ca++-signal was associated with the activation of multiple intracellular signaling pathways and together these events culminated in the rapid de novo synthesis of high amounts of pro-inflammatory cytokines, most notably IFN-gamma and TNF-alpha. Importantly, sustained transmembranous calcium flux, activation of Src-kinases as well as activation of PI3K were found to be absolutely required for CD28SA-mediated production of IFN-gamma and IL-2. Collectively, our data suggest a molecular basis for the severe side effects caused by TGN1412 and impinge upon the relevance of non-human primates as preclinical models for reagents that are supposed to modify the function of human T cells.

Dimeric ligands for GPCRs involved in human reproduction : synthesis and biological evaluation

NARCIS (Netherlands)

Bonger, Kimberly Michelle

2008-01-01

Dimeric ligands for G-protein coupled receptors that are involved in human reproduction, namely the gonadotropin releasing hormone receptor, the luteinizing hormone receptor and the follicle-stimulating hormone receptor, were synthesized and biologically evaluated.

Study the interaction between CdTe-glutathione and human serum albumin

Energy Technology Data Exchange (ETDEWEB)

Yang, Qing; Zhou, Xi-min; Zhu, Yi-shuo [National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen, Xing-guo, E-mail: chenxg@lzu.edu.cn [National Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Department of Chemistry, Lanzhou University, Lanzhou 730000 (China)

2013-03-15

In this paper, glutathione (GSH) modified CdTe quantum dots (CdTe-GSH QDs) were synthesized in an aqueous solution. Then, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using the fluorescence spectroscopy. The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. The fluorescence data revealed that CdTe-GSH QDs could quench the intrinsic fluorescence of human serum albumin by a static quenching mechanism. Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. - Highlights: Black-Right-Pointing-Pointer In this paper, the binding of the CdTe-GSH QDs to human serum albumin (HSA) was studied using a fluorescence spectroscopy. Black-Right-Pointing-Pointer The quenching mechanism was investigated in terms of the association constants and basic thermodynamic parameters. Black-Right-Pointing-Pointer Furthermore, alteration of the secondary protein structure in the presence of the QDs was confirmed by synchronous fluorescence spectra. Black-Right-Pointing-Pointer The research can help us assess biological toxicity of QDs and further expand the application scope of QDs.

In Vivo Lipopolysaccharide Exposure of Human Blood Leukocytes Induces Cross-Tolerance to Multiple TLR Ligands

NARCIS (Netherlands)

de Vos, Alex F.; Pater, Jennie M.; van den Pangaart, Petra S.; de Kruif, Martijn D.; van 't Veer, Cornelis; van der Poll, Tom

2009-01-01

In vitro and in vivo experiments in mice have shown that exposure of cells to the TLR4 ligand LPS induces tolerance toward a second exposure to LPS and induces cross-tolerance to certain other TLR ligands. Recently, we found that LPS tolerance in experimental human endotoxemia and Gram-negative

The role of CD4 and CD8 T cells in human cutaneous leishmaniasis.

Directory of Open Access Journals (Sweden)

Claudia Ida Brodskyn

2014-09-01

Full Text Available Leishmaniasis, caused by infection with parasites of the Leishmania genus, affects millions of individuals worldwide. This disease displays distinct clinical manifestations ranging from self-healing skin lesions to severe tissue damage. The control of Leishmania infection is dependent on cellular immune mechanisms, and evidence has shown that CD4 and CD8 T lymphocytes play different roles in the outcome of leishmaniasis. Although the presence of CD4 T cells is important for controlling parasite growth, the results in the literature suggest that the inflammatory response elicited by these cells could contribute to the pathogenesis of lesions. However, recent studies on CD8 T lymphocytes show that these cells are mainly involved in tissue damage through cytotoxic mechanisms. In this review, we focus on the recent advances in the study of the human adaptive immunological response in the pathogenesis of tegumentary leishmaniasis.

Identification and Functional Characterization of Human Cd4+Cd25+ T Cells with Regulatory Properties Isolated from Peripheral Blood

OpenAIRE

Jonuleit, Helmut; Schmitt, Edgar; Stassen, Michael; Tuettenberg, Andrea; Knop, Jurgen; Enk, Alexander H.

2001-01-01

A subpopulation of peripheral human CD4+CD25+ T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte–associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4+CD25+ T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-...

Influence of CCR7 ligand DNA preexposure on the magnitude and duration of immunity

International Nuclear Information System (INIS)

Lee, Yunsang; Seong, Kug Eo; Rouse, Richard J.D.; Rouse, Barry T.

2003-01-01

The CC chemokine receptor (CCR) 7 ligands CCL21 and CCL19 were recently described as essential elements for establishing the microenvironment needed to initiate optimal immune responses in secondary lymphoid tissues. In the present study we have kinetically investigated the primary responses of naive DO11.10 TCR-transgenic CD4+ T cells (OVA323-339 peptide specific) adoptively transferred into normal BALB/c mice given plasmid DNA encoding CCR7 ligands. The primary responses of CD4+ Tg-T cells in CCR7 ligand DNA recipients occurred more promptly, reaching levels higher than those observed in vector controls. In line with enhanced specific immunity, the T-cell population in CCR7 ligand recipients underwent more in vivo cell division following Ag stimulation, and a higher percentage of Ag-specific T cells expressed an activation phenotype. Moreover, the enhanced primary responses of naive CD4+ T cells appeared to act via affects on migration and maturation of CD11c+ dendritic cells in the draining lymph nodes. In addition following mucosal challenge of herpes simplex virus-immune mice with virus, those that had received CCL21 or CCL19 during priming contained a higher frequency of responding CD4 T cells in lymph nodes and the site of infection. Moreover, CCL21- and CCL19-treated mice showed less severe disease and better survival following challenge. Our results are discussed in terms of the relevance of CCR7 ligand preimmunization to improve vaccine

Modulation of Cytokine Production by Drugs with Antiepileptic or Mood Stabilizer Properties in Anti-CD3- and Anti-CD40-Stimulated Blood In Vitro

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Hubertus Himmerich

2014-01-01

Full Text Available Increased cytokine production possibly due to oxidative stress has repeatedly been shown to play a pivotal role in the pathophysiology of epilepsy and bipolar disorder. Recent in vitro and animal studies of valproic acid (VPA report antioxidative and anti-inflammatory properties, and suppression of interleukin (IL-6 and tumor necrosis factor (TNF-α. We tested the effect of drugs with antiepileptic or mood stabilizer properties, namely, primidone (PRM, carbamazepine (CBZ, levetiracetam (LEV, lamotrigine (LTG, VPA, oxcarbazepine (OXC, topiramate (TPM, phenobarbital (PB, and lithium on the production of the following cytokines in vitro: interleukin (IL-1β, IL-2, IL-4, IL-6, IL-17, IL-22, and TNF-α. We performed a whole blood assay with stimulated blood of 14 healthy female subjects. Anti-human CD3 monoclonal antibody OKT3, combined with 5C3 antibody against CD40, was used as stimulant. We found a significant reduction of IL-1 and IL-2 levels with all tested drugs other than lithium in the CD3/5C3-stimulated blood; VPA led to a decrease in IL-1β, IL-2, IL-4, IL-6, IL-17, and TNF-α production, which substantiates and adds knowledge to current hypotheses on VPA’s anti-inflammatory properties.

In situ identification of CD44+/CD24- cancer cells in primary human breast carcinomas.

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Giuseppe Perrone

Full Text Available Breast cancer cells with the CD44+/CD24- phenotype have been reported to be tumourigenic due to their enhanced capacity for cancer development and their self-renewal potential. The identification of human tumourigenic breast cancer cells in surgical samples has recently received increased attention due to the implications for prognosis and treatment, although limitations exist in the interpretation of these studies. To better identify the CD44+/CD24- cells in routine surgical specimens, 56 primary breast carcinoma cases were analysed by immunofluorescence and confocal microscopy, and the results were compared using flow cytometry analysis to correlate the amount and distribution of the CD44+/CD24- population with clinicopathological features. Using these methods, we showed that the breast carcinoma cells displayed four distinct sub-populations based on the expression pattern of CD44 and CD24. The CD44+/CD24- cells were found in 91% of breast tumours and constituted an average of 6.12% (range, 0.11%-21.23% of the tumour. A strong correlation was found between the percentage of CD44+/CD24- cells in primary tumours and distant metastasis development (p = 0.0001; in addition, there was an inverse significant association with ER and PGR status (p = 0.002 and p = 0.001, respectively. No relationship was evident with tumour size (T and regional lymph node (N status, differentiation grade, proliferative index or HER2 status. In a multivariate analysis, the percentage of CD44+/CD24- cancer cells was an independent factor related to metastasis development (p = 0.004. Our results indicate that confocal analysis of fluorescence-labelled breast cancer samples obtained at surgery is a reliable method to identify the CD44+/CD24- tumourigenic cell population, allowing for the stratification of breast cancer patients into two groups with substantially different relapse rates on the basis of CD44+/CD24- cell percentage.

High PD-L1/CD86 MFI ratio and IL-10 secretion characterize human regulatory dendritic cells generated for clinical testing in organ transplantation.

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Zahorchak, Alan F; Macedo, Camila; Hamm, David E; Butterfield, Lisa H; Metes, Diana M; Thomson, Angus W

2018-01-01

Human regulatory dendritic cells (DCreg) were generated from CD14 immunobead-purified or elutriated monocytes in the presence of vitamin D3 and IL-10. They exhibited similar, low levels of costimulatory CD80 and CD86, but comparatively high levels of co-inhibitory programed death ligand-1 (PD-L1) and IL-10 production compared to control immature DC (iDC). Following Toll-like receptor 4 ligation, unlike control iDC, DCreg resisted phenotypic and functional maturation and further upregulated PD-L1:CD86 expression. Whereas LPS-stimulated control iDC (mature DC; matDC) secreted pro-inflammatory tumor necrosis factor but no IL-10, the converse was observed for LPS-stimulated DCreg. DCreg weakly stimulated naïve and memory allogeneic CD4 + and CD8 + T cell proliferation and IFNγ, IL-17A and perforin/granzyme B production in MLR. Their stimulatory function was enhanced however, by blocking PD-1 ligation. High-throughput T cell receptor (TCR) sequencing revealed that, among circulating T cell subsets, memory CD8 + T cells contained the most alloreactive TCR clonotypes and that, while matDC expanded these alloreactive memory CD8 TCR clonotypes, DCreg induced more attenuated responses. These findings demonstrate the feasibility of generating highly-purified GMP-grade DCreg for systemic infusion, their influence on the alloreactive T cell response, and a key mechanistic role of the PD1 pathway. Copyright © 2017 Elsevier Inc. All rights reserved.