Science.gov

Sample records for direct th2 cell

  1. CD4(+) Th2 cells are directly regulated by IL-10 during allergic airway inflammation.

    PubMed

    Coomes, S M; Kannan, Y; Pelly, V S; Entwistle, L J; Guidi, R; Perez-Lloret, J; Nikolov, N; Müller, W; Wilson, M S

    2017-01-01

    Interleukin-10 (IL-10) is an important regulatory cytokine required to control allergy and asthma. IL-10-mediated regulation of T cell-mediated responses was previously thought to occur indirectly via antigen-presenting cells. However, IL-10 can act directly on regulatory T cells and T helper type 17 (Th17) cells. In the context of allergy, it is therefore unclear whether IL-10 can directly regulate T helper type 2 (Th2) cells and whether this is an important regulatory axis during allergic responses. We sought to determine whether IL-10 signaling in CD4(+) Th2 cells was an important mechanism of immune regulation during airway allergy. We demonstrate that IL-10 directly limits Th2 cell differentiation and survival in vitro and in vivo. Ablation of IL-10 signaling in Th2 cells led to enhanced Th2 cell survival and exacerbated pulmonary inflammation in a murine model of house dust mite allergy. Mechanistically, IL-10R signaling regulated the expression of several genes in Th2 cells, including granzyme B. Indeed, IL-10 increased granzyme B expression in Th2 cells and led to increased Th2 cell death, identifying an IL-10-regulated granzyme B axis in Th2 cells controlling Th2 cell survival. This study provides clear evidence that IL-10 exerts direct effects on Th2 cells, regulating the survival of Th2 cells and severity of Th2-mediated allergic airway inflammation.

  2. Innate immunological function of TH2 cells in vivo.

    PubMed

    Guo, Liying; Huang, Yuefeng; Chen, Xi; Hu-Li, Jane; Urban, Joseph F; Paul, William E

    2015-10-01

    Type 2 helper T cells (TH2 cells) produce interleukin 13 (IL-13) when stimulated by papain or house dust mite extract (HDM) and induce eosinophilic inflammation. This innate response is dependent on IL-33 but not T cell antigen receptors (TCRs). While type 2 innate lymphoid cells (ILC2 cells) are the dominant innate producers of IL-13 in naive mice, we found here that helminth-infected mice had more TH2 cells compared to uninfected mice, and thes e cells became major mediators of innate type 2 responses. TH2 cells made important contributions to HDM-induced antigen-nonspecific eosinophilic inflammation and protected mice recovering from infection with Ascaris suum against subsequent infection with the phylogenetically distant nematode Nippostrongylus brasiliensis. Our findings reveal a previously unappreciated role for effector TH2 cells during TCR-independent innate-like immune responses.

  3. Innate immunological function of TH2 cells in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Th2 cells produce IL-13 when stimulated by papain or house dust mites (HDM) and induce eosinophilic inflammation. This innate response of cells of the adaptive immune system is dependent on IL-33-, not T cell receptor-, based stimulation. While type 2 innate lymphoid cells (ILC2s) are the dominant ...

  4. Innate Immune Function of TH2 Cells in vivo

    PubMed Central

    Guo, Liying; Huang, Yuefeng; Chen, Xi; Hu-Li, Jane; Urban, Joseph F.; Paul, William E.

    2015-01-01

    Type 2 helper T (TH) cells produce interleukin 13 (IL-13) when stimulated by papain or house dust mites (HDM) and induce eosinophilic inflammation. This innate response is dependent on IL-33 but not T cell antigen receptors (TCRs). While type 2 innate lymphoid cells (ILC2s) are the dominant innate producers of IL-13 in naïve animals, we show here that in helminth-infected mice, TH2 cell numbers increased and became major mediators of innate type II responses. TH2 cells made important contributions to HDM-induced antigen–non-specific eosinophilic inflammation and protected mice recovering from Ascaris suum infection against subsequent infection with the phylogenetically distant nematode Nippostrongylus brasiliensis. Our findings reveal a previously unappreciated role of effector TH2 cells during TCR-independent innate-like immune responses. PMID:26322482

  5. Morphine withdrawal contributes to Th cell differentiation by biasing cells toward the Th2 lineage.

    PubMed

    Kelschenbach, Jennifer; Barke, Roderick A; Roy, Sabita

    2005-08-15

    The consequences that drug withdrawal has on immune functioning has only recently been appreciated; however, given the wide variety of use and abuse of opiate analgesics, understanding the decrements to immune function that withdrawal from these drugs causes is of crucial importance. In previous work, we have demonstrated that morphine treatment contributes to immunosuppression by polarizing Th cells toward the Th2 lineage. In the current study, it was hypothesized that morphine withdrawal would result in Th2 differentiation and subsequent immune dysfunction. To address this hypothesis, mice were chronically treated with morphine for 72 h followed by a 24-h withdrawal period. It was determined that 24-h morphine withdrawal resulted in a decrease in IFN-gamma, the Th1 signature cytokine, whereas the Th2 cytokine, IL-4, was increased. In addition, Western blot and EMSA experiments revealed that morphine withdrawal-induced Th2 differentiation was mediated through the classical Th2 transcription factors Stat-6 and GATA-3. In addition, the consequence of morphine withdrawal in the presence of an immune stimulation was also examined by treating mice in vivo with LPS before morphine withdrawal. Following withdrawal, it was found that the Th1-polarizing cytokine IL-12 was significantly decreased, providing further support for the observation that withdrawal results in Th2 differentiation by possibly impacting the generation of an appropriate innate immune response which directs subsequent adaptive Th1/Th2 responses.

  6. Hierarchical IL-5 expression defines a subpopulation of highly differentiated human Th2 cells.

    PubMed

    Upadhyaya, Bhaskar; Yin, Yuzhi; Hill, Brenna J; Douek, Daniel C; Prussin, Calman

    2011-09-15

    Each of the three Th2 cytokine genes, IL-4, IL-5, and IL-13, has different functions. We hypothesized that Th2 heterogeneity could yield Th2 subpopulations with different cytokine expression and effector functions. Using multiple approaches, we demonstrate that human Th2 cells are composed of two major subpopulations: a minority IL-5(+) (IL-5(+), IL-4(+), IL-13(+)) and majority IL-5(-) Th2 (IL-5(-), IL-4(+), IL-13(+)) population. IL-5(+) Th2 cells comprised only 20% of all Th2 cells. Serial rounds of in vitro differentiation initially yielded IL-5(-) Th2, but required multiple rounds of differentiation to generate IL-5(+) Th2 cells. IL-5(+) Th2 cells expressed less CD27 and greater programmed cell death-1 than IL-5(-) Th2 cells, consistent with their being more highly differentiated, Ag-exposed memory cells. IL-5(+) Th2 cells expressed greater IL-4, IL-13, and GATA-3 relative to IL-5(-) Th2 cells. GATA-3 and H3K4me(3) binding to the IL5 promoter (IL5p) was greater in IL-5(+) relative to IL-5(-) Th2 cells, whereas there was no difference in their binding to the IL4p and IL13p. Conversely, H3K27me(3) binding to the IL5p was greater in IL-5(-) Th2 cells. These findings demonstrate Th2 lineage heterogeneity, in which the IL5 gene is regulated in a hierarchical manner relative to other Th2 genes. IL-5(+) Th2 cells are phenotypically distinct and have epigenetic changes consistent with greater IL5p accessibility. Recurrent antigenic exposure preferentially drives the differentiation of IL-5(+) Th2 cells. These results demonstrate that IL-5(+) and IL-5(-) Th2 cells, respectively, represent more and less highly differentiated Th2 cell subpopulations. Such Th2 subpopulations may differentially contribute to Th2-driven pathology.

  7. Transcription factor IRF4 drives dendritic cells to promote Th2 differentiation

    NASA Astrophysics Data System (ADS)

    Williams, Jesse W.; Tjota, Melissa Y.; Clay, Bryan S.; Vander Lugt, Bryan; Bandukwala, Hozefa S.; Hrusch, Cara L.; Decker, Donna C.; Blaine, Kelly M.; Fixsen, Bethany R.; Singh, Harinder; Sciammas, Roger; Sperling, Anne I.

    2013-12-01

    Atopic asthma is an inflammatory pulmonary disease associated with Th2 adaptive immune responses triggered by innocuous antigens. While dendritic cells (DCs) are known to shape the adaptive immune response, the mechanisms by which DCs promote Th2 differentiation remain elusive. Herein we demonstrate that Th2-promoting stimuli induce DC expression of IRF4. Mice with conditional deletion of Irf4 in DCs show a dramatic defect in Th2-type lung inflammation, yet retain the ability to elicit pulmonary Th1 antiviral responses. Using loss- and gain-of-function analysis, we demonstrate that Th2 differentiation is dependent on IRF4 expression in DCs. Finally, IRF4 directly targets and activates the Il-10 and Il-33 genes in DCs. Reconstitution with exogenous IL-10 and IL-33 recovers the ability of Irf4-deficient DCs to promote Th2 differentiation. These findings reveal a regulatory module in DCs by which IRF4 modulates IL-10 and IL-33 cytokine production to specifically promote Th2 differentiation and inflammation.

  8. Both Th1 and Th2 Cells Require P-Selectin Glycoprotein Ligand-1 for Optimal Rolling on Inflamed Endothelium

    PubMed Central

    Mangan, Paul R.; O’Quinn, Darrell; Harrington, Laurie; Bonder, Claudine S.; Kubes, Paul; Kucik, Dennis F.; Bullard, Daniel C.; Weaver, Casey T.

    2005-01-01

    The acquisition of homing receptors that redirect lymphocyte trafficking to nonlymphoid tissues after antigen encounter is a fundamental aspect of effector T-cell development. Although a role for selectins and their ligands has been well characterized for trafficking of Th1 cells to nonlymphoid sites, mechanisms responsible for Th2 trafficking are not well understood. Using a flow chamber system in which the endothelial interactions of two distinct T-cell populations could be examined simultaneously, we directly compared the requirements for Th1 and Th2 cell tethering and rolling. We found that although Th2 cells expressed significantly lower levels of selectin ligands than Th1 cells, activation of the endothelium by Th2-derived factors induced rolling interactions that were comparable for both Th1 and Th2 populations. Further, in the absence of PSGL-1, no other adhesion molecule could effectively compensate for lack of PSGL-1 to mediate rolling of either Th1 or Th2 cells. Thus, both Th1 and Th2 populations express functional PSGL-1-based selectin ligands for tethering and rolling on activated endothelium, and both effector populations can use PSGL-1 as the dominant scaffold for functional selectin ligand expression. PMID:16314478

  9. T-cell-intrinsic Tif1α/Trim24 regulates IL-1R expression on TH2 cells and TH2 cell-mediated airway allergy.

    PubMed

    Perez-Lloret, Jimena; Okoye, Isobel S; Guidi, Riccardo; Kannan, Yashaswini; Coomes, Stephanie M; Czieso, Stephanie; Mengus, Gabrielle; Davidson, Irwin; Wilson, Mark S

    2016-02-02

    There is a paucity of new therapeutic targets to control allergic reactions and forestall the rising trend of allergic diseases. Although a variety of immune cells contribute to allergy, cytokine-secreting αβ(+)CD4(+) T-helper 2 (TH2) cells orchestrate the type-2-driven immune response in a large proportion of atopic asthmatics. To identify previously unidentified putative targets in pathogenic TH2 cells, we performed in silico analyses of recently published transcriptional data from a wide variety of pathogenic TH cells [Okoye IS, et al. (2014) Proc Natl Acad Sci USA 111(30):E3081-E3090] and identified that transcription intermediary factor 1 regulator-alpha (Tif1α)/tripartite motif-containing 24 (Trim24) was predicted to be active in house dust mite (HDM)- and helminth-elicited Il4(gfp+)αβ(+)CD4(+) TH2 cells but not in TH1, TH17, or Treg cells. Testing this prediction, we restricted Trim24 deficiency to T cells by using a mixed bone marrow chimera system and found that T-cell-intrinsic Trim24 is essential for HDM-mediated airway allergy and antihelminth immunity. Mechanistically, HDM-elicited Trim24(-/-) T cells have reduced expression of many TH2 cytokines and chemokines and were predicted to have compromised IL-1-regulated signaling. Following this prediction, we found that Trim24(-/-) T cells have reduced IL-1 receptor (IL-1R) expression, are refractory to IL-1β-mediated activation in vitro and in vivo, and fail to respond to IL-1β-exacerbated airway allergy. Collectively, these data identify a previously unappreciated Trim24-dependent requirement for IL-1R expression on TH2 cells and an important nonredundant role for T-cell-intrinsic Trim24 in TH2-mediated allergy and antihelminth immunity.

  10. Different growth factor requirements for human Th2 cells may reflect in vivo induced anergy.

    PubMed Central

    Van Reijsen, F C; Wijburg, O L; Gebhardt, M; Van Ieperen-Van Dijk, A G; Betz, S; Poellabauer, E M; Thepen, T; Bruijnzeel-Koomen, C A; Mudde, G C

    1994-01-01

    We previously reported the isolation of allergen-specific Th2 lines and clones from atopy patch test (APT) sites of atopic dermatitis (AD) patients. Upon stimulation with allergen or anti-CD3+ phorbol myristate acetate (PMA) IL-4 was released with or without IL-5, while no (or extremely low concentrations of) IL-2 and interferon-gamma (IFN-gamma) were detectable. A high IL-4/IFN-gamma ratio facilitates production of allergen-specific IgE, of which high levels are observed in AD patients. Here we show that the above mentioned Th2 cells are notably different from murine Th2 cells. Not IL-4, which is the autocrine acting growth factor for murine Th2 cells, but IL-2 was needed for proliferation of these human APT-derived Th2 lines and clones. Of significance, unless exogenous IL-2 was added, no proliferative response to allergen, presented by Epstein-Barr virus-transformed B (EBV-B) cells, non-T cells or IgE-bearing Langerhans cells (LC), occurred. Lack of proliferation and IL-2 production after full T cell receptor (TCR) triggering is a characteristic first described for in vitro anergized T cells. However, like the clones we describe in this study, anergic T cells may retain production of cytokines other than IL-2. A further resemblance between anergic T cells and the human Th2 clones reported here is that IL-4 can enhance IL-2-driven proliferation, but is not capable of inducing T cell growth by itself. The absence of IL-4-driven proliferation differentiates human Th2 cells from murine Th2 cells. Both produce IL-4 when stimulated in a cognate fashion, but only murine Th2 cells will proliferate. We conclude that the presently reported human Th2 cells are different from murine Th2 cells, in that they need other T cells to produce IL-2 required for their expansion. Moreover, the Th2 cells phenotypically resemble anergic T cells. As yet, however, we have no clue as to whether these features account for the current Th2 cells only or for human Th2 cells in general. We

  11. Quantitative analysis of peripheral blood Th0, Th1, Th2 and the Th1:Th2 cell ratio during normal human pregnancy and preeclampsia

    PubMed Central

    Saito, S; Sakai, M; Sasaki, Y; Tanebe, K; Tsuda, H; Michimata, T

    1999-01-01

    We calculated the percentage of Th1, Th2, Th0 cells and the Th1:Th2 cell ratio of peripheral blood from normal pregnant subjects and preeclampsia patients using flow cytometry which can analyse both the surface marker, CD4, and intracellular cytokines, interleukin (IL)-4 and interferon (IFN)-γ. In normal pregnancy, the percentage of Th1 cells was significantly lower in the third trimester, and the ratios of Th1:Th2 were significantly lower in the second and third trimester than in nonpregnant subjects. In contrast, the percentage of Th1 cells and the ratios of Th1:Th2 in preeclampsia were significantly higher than in normal third trimester pregnant subjects. The percentage of Th2 cells in preeclampsia was significantly lower than in third trimester of normal pregnancy. Additionally, peripheral blood mononuclear cells from these subjects and patients were cultured with phytohemagglutinin stimulation, and IL-4 and IFN-γ concentrations were determined in the supernatant by enzymed linked immunosorbent assays. The percentage of Th1 and Th2, and the ratios of Th1:Th2 were correlated with cytokine (IFN-γ and IL-4) secretion level. These results demonstrated that Th2 cells were predominant in the second and third trimesters of normal pregnancy, but Th1 cells predominated in preeclamptic patients. PMID:10469061

  12. IL25 elicits a multipotent progenitor cell population that promotes TH2 cytokine responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4+ T helper 2 (TH2) cells secrete interleukin (IL)4, IL5 and IL13, and are required for immunity to gastrointestinal helminth infections. However, TH2 cells also promote chronic inflammation associated with asthma and allergic disorders. The non-haematopoietic-cell-derived cytokines thymic stromal...

  13. CD4+ T-cell subsets in inflammatory diseases: beyond the Th1/Th2 paradigm

    PubMed Central

    Hirahara, Kiyoshi

    2016-01-01

    CD4+ T cells are crucial for directing appropriate immune responses during host defense and for the pathogenesis of inflammatory diseases. In addition to the classical biphasic model of differentiation of T-helper 1 (Th1) and Th2 cells, unexpected increases in the numbers of CD4+ T-cell subsets, including Th17, Th9, T follicular-helper (Tfh) and T-regulatory (Treg) cells, have been recognized. In the present review, we focus on how these various T-helper cell subsets contribute to the pathogenesis of immune-mediated inflammatory diseases. In particular, we focus on multiple sclerosis, psoriasis and asthma as typical model diseases in which multiple T-helper cell subsets have recently been suggested to play a role. We will also discuss various unique sub-populations of T-helper cells that have been identified. First, we will introduce the heterogeneous T-helper cell subsets, which are classified by their simultaneous expression of multiple key transcription factors. We will also introduce different kinds of memory-type Th2 cells, which are involved in the pathogenesis of chronic type-2 immune-related diseases. Finally, we will discuss the molecular mechanisms underlying the generation of the plasticity and heterogeneity of T-helper cell subsets. The latest progress in the study of T-helper cell subsets has forced us to reconsider the etiology of immune-mediated inflammatory diseases beyond the model based on the Th1/Th2 balance. To this end, we propose another model—the pathogenic T-helper population disease-induction model—as a possible mechanism for the induction and/or persistence of immune-mediated inflammatory diseases. PMID:26874355

  14. T-cell–intrinsic Tif1α/Trim24 regulates IL-1R expression on TH2 cells and TH2 cell-mediated airway allergy

    PubMed Central

    Perez-Lloret, Jimena; Okoye, Isobel S.; Guidi, Riccardo; Kannan, Yashaswini; Coomes, Stephanie M.; Czieso, Stephanie; Mengus, Gabrielle; Davidson, Irwin; Wilson, Mark S.

    2016-01-01

    There is a paucity of new therapeutic targets to control allergic reactions and forestall the rising trend of allergic diseases. Although a variety of immune cells contribute to allergy, cytokine-secreting αβ+CD4+ T-helper 2 (TH2) cells orchestrate the type-2–driven immune response in a large proportion of atopic asthmatics. To identify previously unidentified putative targets in pathogenic TH2 cells, we performed in silico analyses of recently published transcriptional data from a wide variety of pathogenic TH cells [Okoye IS, et al. (2014) Proc Natl Acad Sci USA 111(30):E3081–E3090] and identified that transcription intermediary factor 1 regulator-alpha (Tif1α)/tripartite motif-containing 24 (Trim24) was predicted to be active in house dust mite (HDM)- and helminth-elicited Il4gfp+αβ+CD4+ TH2 cells but not in TH1, TH17, or Treg cells. Testing this prediction, we restricted Trim24 deficiency to T cells by using a mixed bone marrow chimera system and found that T-cell–intrinsic Trim24 is essential for HDM-mediated airway allergy and antihelminth immunity. Mechanistically, HDM-elicited Trim24−/− T cells have reduced expression of many TH2 cytokines and chemokines and were predicted to have compromised IL-1–regulated signaling. Following this prediction, we found that Trim24−/− T cells have reduced IL-1 receptor (IL-1R) expression, are refractory to IL-1β–mediated activation in vitro and in vivo, and fail to respond to IL-1β–exacerbated airway allergy. Collectively, these data identify a previously unappreciated Trim24-dependent requirement for IL-1R expression on TH2 cells and an important nonredundant role for T-cell–intrinsic Trim24 in TH2-mediated allergy and antihelminth immunity. PMID:26787865

  15. IFNγ and IL-12 Restrict Th2 Responses during Helminth/Plasmodium Co-Infection and Promote IFNγ from Th2 Cells

    PubMed Central

    Coomes, Stephanie M.; Pelly, Victoria S.; Kannan, Yashaswini; Okoye, Isobel S.; Czieso, Stephanie; Entwistle, Lewis J.; Perez-Lloret, Jimena; Nikolov, Nikolay; Potocnik, Alexandre J.; Biró, Judit; Langhorne, Jean; Wilson, Mark S.

    2015-01-01

    Parasitic helminths establish chronic infections in mammalian hosts. Helminth/Plasmodium co-infections occur frequently in endemic areas. However, it is unclear whether Plasmodium infections compromise anti-helminth immunity, contributing to the chronicity of infection. Immunity to Plasmodium or helminths requires divergent CD4+ T cell-driven responses, dominated by IFNγ or IL-4, respectively. Recent literature has indicated that Th cells, including Th2 cells, have phenotypic plasticity with the ability to produce non-lineage associated cytokines. Whether such plasticity occurs during co-infection is unclear. In this study, we observed reduced anti-helminth Th2 cell responses and compromised anti-helminth immunity during Heligmosomoides polygyrus and Plasmodium chabaudi co-infection. Using newly established triple cytokine reporter mice (Il4gfpIfngyfpIl17aFP635), we demonstrated that Il4gfp+ Th2 cells purified from in vitro cultures or isolated ex vivo from helminth-infected mice up-regulated IFNγ following adoptive transfer into Rag1–/– mice infected with P. chabaudi. Functionally, Th2 cells that up-regulated IFNγ were transcriptionally re-wired and protected recipient mice from high parasitemia. Mechanistically, TCR stimulation and responsiveness to IL-12 and IFNγ, but not type I IFN, was required for optimal IFNγ production by Th2 cells. Finally, blockade of IL-12 and IFNγ during co-infection partially preserved anti-helminth Th2 responses. In summary, this study demonstrates that Th2 cells retain substantial plasticity with the ability to produce IFNγ during Plasmodium infection. Consequently, co-infection with Plasmodium spp. may contribute to the chronicity of helminth infection by reducing anti-helminth Th2 cells and converting them into IFNγ-secreting cells. PMID:26147567

  16. Caerulomycin A inhibits Th2 cell activity: a possible role in the management of asthma

    PubMed Central

    Kujur, Weshely; Gurram, Rama Krishna; Haleem, Nazia; Maurya, Sudeep K.; Agrewala, Javed N.

    2015-01-01

    We have recently demonstrated that Caerulomycin A induces regulatory T cells differentiation by suppressing Th1 cells activity. The role of regulatory T cells is well established in suppressing the function of Th2 cells. Th2 cells are known to inflict the induction of the activation of asthma. Consequently, in the present study, we monitored the influence of Caerulomycin A in inhibiting the activity of Th2 cells and its impact in recuperating asthma symptoms. Interestingly, we observed that Caerulomycin A significantly suppressed the differentiation of Th2 cells, as evidenced by downregulation in the GATA-3 expression. Further, decline in the levels of IL-4, IL-5 and IL-13 cytokines and IgE was noted in the animals suffering from asthma. Furthermore, we noticed substantial suppression in the inflammatory response and number of eosinophils in the lungs. In essence, this study signifies an important therapeutic role of Caerulomycin A in asthma. PMID:26481184

  17. TH2, allergy and group 2 innate lymphoid cells.

    PubMed

    Licona-Limón, Paula; Kim, Lark Kyun; Palm, Noah W; Flavell, Richard A

    2013-06-01

    The initiation of type 2 immune responses by the epithelial cell-derived cytokines IL-25, IL-33 and TSLP has been an area of extensive research in the past decade. Such studies have led to the identification of a new innate lymphoid subset that produces the canonical type 2 cytokines IL-5, IL-9 and IL-13 in response to IL-25 and IL-33. These group 2 or type 2 innate lymphoid cells (ILC2 cells) represent a critical source of type 2 cytokines in vivo and serve an important role in orchestrating the type 2 response to helminths and allergens. Further characterization of ILC2 cell biology will enhance the understanding of type 2 responses and may identify new treatments for asthma, allergies and parasitic infections. Interactions between ILC2 cells and the adaptive immune system, as well as examination of potential roles for ILC2 cells in the maintenance of homeostasis, promise to be particularly fruitful areas of future research.

  18. CD30 antigen: not a physiological marker for TH2 cells but an important costimulator molecule in the regulation of the balance between TH1/TH2 response.

    PubMed

    Pellegrini, Patrizia; Berghella, Anna Maria; Contasta, Ida; Adorno, Domenico

    2003-01-01

    Understanding the physiological role of CD30 would be an important step forward in transplants because CD30+ T cells can be induced by alloantigens even in the presence of immunosuppressives such as cyclosporine (Csa) and hence can act as regulatory cells in allograft. The results of functional studies on purified T CD30+ cell populations led us to hypothesize that the CD30 costimulator molecule is not a specific marker for TH2 cells in normal conditions, as has been suggested, but rather a marker for an important immunoregulatory subpopulation that regulates the balance between TH1 and TH2 (TH1/TH2) type response. To substantiate this hypothesis we studied the TH1/TH2 cytokine network in peripheral whole blood cultures stimulate with M44 CD30 ligand (CD30L), an agonistic monoclonal antibody (mAb). Four types of whole blood culture were used: the first had been stimulated with anti-CD3 mAb which generates a CD30 cytokine profile similar to alloreactive stimulation; the second with anti-CD3 mAb+M81 (an anti-CD30L mAb) to inhibit CD30/CD30L interaction; the third with anti-CD3+anti-interleukin (IL)4 mAbs to counteract IL4 activity and the fourth with anti-CD3+anti-interferon (IFN)gamma mAbs to counteract IFNgamma activity. Network interactions between soluble CD30 (sCD30, a maker of CD30 expression), sBcl2 (a marker of cell survival) and TH1/TH2 cytokines (IFNgamma, IL2, IL12p70, IL12p40, IL4, IL5 and IL10) were then studied in the supernatants obtained. Our results confirm the hypothesis above by showing that CD30 signals trigger functional mechanisms responsible for changes in levels of production of several important TH1 and TH2 cytokines involved in the regulation of the physiological balance between TH1/TH2 functions. The CD30-stimulated network, in fact, induces IFNgamma production linked to TH1 activity (-->TH1) which is subsequently integrated by IL4 production linked to TH2 activity (-->TH2). This production appears to be regulated, respectively, by IL12p40

  19. Eotaxins and CCR3 interaction regulates the Th2 environment of cutaneous T-cell lymphoma.

    PubMed

    Miyagaki, Tomomitsu; Sugaya, Makoto; Fujita, Hideki; Ohmatsu, Hanako; Kakinuma, Takashi; Kadono, Takafumi; Tamaki, Kunihiko; Sato, Shinichi

    2010-09-01

    CC chemokine receptor 3 (CCR3), the sole receptor for eotaxins, is expressed on eosinophils and T helper type 2 (Th2) cells. In Hodgkin's disease, eotaxin-1 secreted by fibroblasts collects Th2 cells and eosinophils within the tissue. Similarly, many Th2 cells infiltrate the lesional skin of cutaneous T-cell lymphoma (CTCL). In this study, we investigated the role of eotaxins in the development of the Th2 environment of CTCL. We revealed that fibroblasts from lesional skin of CTCL expressed higher amounts of eotaxin-3 messenger RNA (mRNA) compared with those from normal skin. Lesional skin of CTCL at advanced stages contained significantly higher levels of eotaxin-3 and CCR3 mRNA, compared with early stages of CTCL. IL-4 mRNA was expressed in some cases at advanced stages. Immunohistochemistry revealed that keratinocytes, endothelial cells, and dermal fibroblasts in lesional skin of CTCL showed a stronger expression of eotaxin-3 than did normal skin. CCR3(+) lymphocytes and IL-4 expression were observed in some cases of advanced CTCL. Furthermore, both serum eotaxin-3 and eotaxin-1 levels of CTCL patients at advanced stages were significantly higher than those of healthy individuals. The concentrations of these chemokines correlated with serum soluble IL-2 receptor levels. These results suggest that interaction of eotaxins and CCR3 regulates the Th2-dominant tumor environment, which is closely related to the development of CTCL.

  20. Thimerosal induces TH2 responses via influencing cytokine secretion by human dendritic cells.

    PubMed

    Agrawal, Anshu; Kaushal, Poonam; Agrawal, Sudhanshu; Gollapudi, Sastry; Gupta, Sudhir

    2007-02-01

    Thimerosal is an organic mercury compound that is used as a preservative in vaccines and pharmaceutical products. Recent studies have shown a TH2-skewing effect of mercury, although the underlying mechanisms have not been identified. In this study, we investigated whether thimerosal can exercise a TH2-promoting effect through modulation of functions of dendritic cells (DC). Thimerosal, in a concentration-dependent manner, inhibited the secretion of LPS-induced proinflammatory cytokines TNF-alpha, IL-6, and IL-12p70 from human monocyte-derived DC. However, the secretion of IL-10 from DC was not affected. These thimerosal-exposed DC induced increased TH2 (IL-5 and IL-13) and decreased TH1 (IFN-gamma) cytokine secretion from the T cells in the absence of additional thimerosal added to the coculture. Thimerosal exposure of DC led to the depletion of intracellular glutathione (GSH), and addition of exogenous GSH to DC abolished the TH2-promoting effect of thimerosal-treated DC, restoring secretion of TNF-alpha, IL-6, and IL-12p70 by DC and IFN-gamma secretion by T cells. These data suggest that modulation of TH2 responses by mercury and thimerosal, in particular, is through depletion of GSH in DC.

  1. Th2 cells are essential for modulation of vascular repair by allogeneic endothelial cells

    PubMed Central

    Methe, Heiko; Nanasato, Mamoru; Spognardi, Anna-Maria; Groothuis, Adam; Edelman, Elazer R.

    2009-01-01

    Background Endothelial cells (EC) embedded within three-dimensional matrices (MEEC) when placed in the vascular adventitia control lumenal inflammation and intimal hyperplasia. Matrix-embedding alters endothelial immunogenicity in vitro. T helper (Th) driven host immunity is a major impediment for of allogeneic grafts. We therefore aimed to identify if modulation of T helper balance would affect immune compatibility and endothelial regulation of vascular repair in vivo. Methods Pigs (n=4/group) underwent balloon injury of both carotid arteries and were left alone (group 1) or received perivascular implants of porcine MEEC (group 2), a 12 days course of cyclosporine A (CsA) (group 3), or a combination of MEEC and CsA (group 4). Host immune reactivity (EC-specific antibodies, activation of splenocytes) was analyzed after 28 and 90 days in 2 pigs/group respectively. Results MEEC treatment alone induced formation of EC-specific IgG1-antibodies (41±6 mean fluorescence intensity (MFI)) and differentiation of host splenocytes into Th2, but not Th1, cytokine-producing cells (IL-4: 242±102, IL-10: 273±114 number of spots). Concomitant CsA-therapy reduced the frequency of IgG1-antibodies (25±2 MFI; p<0.02) and Th2-cytokine producing splenocytes upon MEEC treatment (IL-4: 157±19, IL-10: 124±26 number of spots; p< 0.05). MEEC significantly inhibited luminal occlusion 28 and 90 days after balloon injury compared to untreated controls (12±7 vs. 68±14%; p<0.001) but to a lesser extent in the face of immunomodulation with concomitant CsA-treatment (34±13%; p<0.02 vs. group 2). Conclusions MEEC do not induce a significant Th1-driven immune response expected from alloimplants, but do enhance differentiation of splenocytes into Th2-cytokine producing cells. Reduction in this Th2 response reduces the vasoregulatory effects of allogeneic EC after injury. PMID:20036161

  2. The expanding universe of T-cell subsets: Th1, Th2 and more.

    PubMed

    Mosmann, T R; Sad, S

    1996-03-01

    Since their discovery nearly ten years ago, T helper 1 (Th1) and Th2 subsets have been implicated in the regulation of many immune responses. In this article, Tim Mosmann and Subash Sad discuss the increasing number of T-cell subsets defined by cytokine patterns; the differentiation pathways of CD4+ and CD8+ T cells; the contribution of other cell types to these patterns; and the cytokine interactions during infection and pregnancy.

  3. Transcription mediated by NFAT is highly inducible in effector CD4+ T helper 2 (Th2) cells but not in Th1 cells.

    PubMed Central

    Rincón, M; Flavell, R A

    1997-01-01

    Transcriptional factors of the NFAT family play an important role in regulating the expression of several cytokine genes during the immune response, such as the genes for interleukin 2 (IL-2) and IL-4, among others. Upon antigen stimulation, precursor CD4+ T helper (pTh) cells proliferate and differentiate into two populations of effector cells (eTh1 and eTh2), each one expressing a specific pattern of cytokines that distinguishes them from their precursors. eTh2 cells are the major source of IL-4, while gamma interferon is produced by eTh1 cells. Here we have used reporter transgenic mice to show that DNA binding and transcriptional activities of NFAT are transiently induced during the differentiation of pTh cells into either eTh1 or eTh2 cells to mediate the expression of IL-2 as a common growth factor in both pathways. However, although NFAT DNA binding is similarly induced in both eTh1 and eTh2 cells upon antigen stimulation, only the NFAT complexes present in eTh2 cells are able to mediate high-level transcription, and relatively little NFAT transcriptional activity was induced in eTh1 cells. In contrast to activated pTh cells, neither eTh1 nor eTh2 cells produced significant IL-2 upon stimulation, but the high levels of NFAT transcriptional activities directly correlate with the IL-4 production induced in response to antigen stimulation in eTh2 cells. These data suggest that activated NFAT is involved in the effector function of eTh2 cells and that the failure of eTh1 cells to produce IL-4 in response to an antigen is due, at least partially, to a failure to induce high-level transcription of the IL-4 gene by NFAT. Regulation of NFAT could be therefore a critical element in the polarization to eTh1 or eTh2. PMID:9032280

  4. Akt1-mediated Gata3 phosphorylation controls the repression of IFNγ in memory-type Th2 cells

    PubMed Central

    Hosokawa, Hiroyuki; Tanaka, Tomoaki; Endo, Yusuke; Kato, Miki; Shinoda, Kenta; Suzuki, Akane; Motohashi, Shinichiro; Matsumoto, Masaki; Nakayama, Keiichi I.; Nakayama, Toshinori

    2016-01-01

    Th2 cells produce Th2 cytokines such as IL-4, IL-5 and IL-13, but repress Th1 cytokine IFNγ. Recent studies have revealed various distinct memory-type Th2 cell subsets, one of which produces a substantial amount of IFNγ in addition to Th2 cytokines, however it remains unclear precisely how these Th2 cells produce IFNγ. We herein show that phosphorylation of Gata3 at Ser308, Thr315 and Ser316 induces dissociation of a histone deacetylase Hdac2 from the Gata3/Chd4 repressive complex in Th2 cells. We also identify Akt1 as a Gata3-phosphorylating kinase, and the activation of Akt1 induces derepression of Tbx21 and Ifng expression in Th2 cells. Moreover, T-bet-dependent IFNγ expression in IFNγ-producing memory Th2 cells appears to be controlled by the phosphorylation status of Gata3 in human and murine systems. Thus, this study highlights the molecular basis for posttranslational modifications of Gata3 that control the regulation of IFNγ expression in memory Th2 cells. PMID:27053161

  5. Plasmacytoid dendritic cells prevent cigarette smoke and Chlamydophila pneumoniae-induced Th2 inflammatory responses.

    PubMed

    Sorrentino, Rosalinda; Gray, Pearl; Chen, Shuang; Shimada, Kenichi; Crother, Timothy R; Arditi, Moshe

    2010-10-01

    Smoking promotes the development of allergic asthma and pneumonia. Chlamydophila pneumoniae lung infection is associated with an increased risk for asthma, inducing an immune response regulated by dendritic cells (DCs). This study sought to determine whether exposure to cigarette smoke modulates the functional activity of CD11c-positive DCs in the lung, with and without concomitant C. pneumoniae infection. Bone marrow-derived DCs (BMDCs) were exposed in vitro to cigarette smoke extract (CSE) and/or live C. pneumoniae (Cpn), and then adoptively transferred intratracheally into wild-type mice. Although CSE plus Cpn appeared to exert an additive effect on the production of Th2 cytokines in vitro, we did not see this effect in vivo. However, the adoptive transfer of DCs pulsed with both CSE and C. pneumoniae into the lungs of naive mice led to an influx of plasmacytoid DCs (pDCs) that suppressed the Th2 skewing ability of the transferred BMDCs. The depletion of pDCs by antibody restored the Th2 skewing ability of the BMDCs. The expression of indoleamine-2,3-dioxygenase in the lung was reduced after the depletion of pDCs, and blocking IFN-α in vitro prevented the ability of pDCs to inhibit the Th2 responses induced by myeloid DCs (mDCs), suggesting their potential involvement in the mechanism of altered polarization. In conclusion, exposure to cigarette smoke skews C. pneumoniae-induced mDCs responses toward a Th2 bias in the lung, which is prevented by pDCs. We propose that pDCs may play a major role in the immunosuppressive lung environment in smokers with C. pneumoniae infection.

  6. T-cell clones in human trichinellosis: Evidence for a mixed Th1/Th2 response.

    PubMed

    Della Bella, C; Benagiano, M; De Gennaro, M; Gomez-Morales, M A; Ludovisi, A; D'Elios, S; Luchi, S; Pozio, E; D'Elios, M M; Bruschi, F

    2017-03-01

    In humans, studies on the cellular immune response against Trichinella are scarce. Aim of this study was to characterize the cytokine profile of T cells specific for Trichinella britovi in trichinellosis patients. Peripheral blood mononuclear cells (PBMC) were obtained from five patients involved in a trichinellosis outbreak caused by T. britovi, which occurred in 2013 in Tuscany (Italy). All the patients resulted positive for Trichinella-specific IgG, IgE and presented eosinophilia. T cells were investigated for their proliferation to excretory/secretory antigens from Trichinella spiralis muscle larvae (TsES) and for their cytokine profile. A total of 284 CD4+ and 42 CD8+ T-cell clones were obtained from the TsES-specific T-cell lines from PBMC. All T-cell clones proliferated in response to mitogen. Of the 284 CD4+ T-cell clones generated from TsES-specific T-cell lines, 135 (47%) proliferated significantly to TsES; 26% CD8+ T-cell clones showed proliferation to TsES. In the series of the 135 TsES-specific CD4+ clones, 51% expressed a Th2 profile, 30% a Th0 and 19% Th1. In the series of the 11 TsES-specific CD8+ T-cell clones, 18% were Tc2, 45% Tc0 and 36% Tc1. In human trichinellosis, the cellular immune response is, during the chronic phase, mixed Th1/Th2.

  7. Traditional Korean medicine (SCRT) modulate Th1/Th2 specific cytokine production in mice CD4+ T cell.

    PubMed

    Ko, Eunjung; Rho, Samwoong; Lee, Eui-Joon; Seo, Young-Ho; Cho, Chongwoon; Lee, Yongwon; Min, Byung-Il; Shin, Min-Kyu; Hong, Moo-Chang; Bae, Hyunsu

    2004-05-01

    Traditional Korea medicine, So-Cheong-Ryong-Tang (SCRT) also called as Xiao-qing-long-tang or Sho-seiru-to, contains eight species of medicinal plants and has been used for treating allergic diseases, such as allergic rhinitis and asthma, for hundreds of years in Asian countries. CD4+ T cells were highly purified by using magnetic bead from splenocytes of BALB/c mice. SCRT treatment slightly decreased the expression of cell surface protein CD69 on CD4+ T cell in the flow cytometry analysis. In RT-PCR analysis, SCRT increases the expression of IL-2 and IL2R-alpha mRNA, and decreases the expression of IL-4 mRNA, which is an important cytokine of Th2 cell development. On the other hand, SCRT treatment increases IFN-gamma expression, which is one of the key cytokines for Th1 cell development. Present study implies that SCRT can correct Th2 dominant condition directly affecting to the CD4+ T cell without significantly depressing general T cell activities. These results also suggest that the effect on CD4+ T cell may be the one of key pharmacological effect point for treating IgE medicated allergic asthma by SCRT.

  8. CD4 T-Cell Subsets in Malaria: TH1/TH2 Revisited

    PubMed Central

    Perez-Mazliah, Damian; Langhorne, Jean

    2015-01-01

    CD4+ T-cells have been shown to play a central role in immune control of infection with Plasmodium parasites. At the erythrocytic stage of infection, IFN-γ production by CD4+ T-cells and CD4+ T-cell help for the B-cell response are required for control and elimination of infected red blood cells. CD4+ T-cells are also important for controlling Plasmodium pre-erythrocytic stages through the activation of parasite-specific CD8+ T-cells. However, excessive inflammatory responses triggered by the infection have been shown to drive pathology. Early classical experiments demonstrated a biphasic CD4+ T-cell response against erythrocytic stages in mice, in which T helper (Th)1 and antibody-helper CD4+ T-cells appear sequentially during a primary infection. While IFN-γ-producing Th1 cells do play a role in controlling acute infections, and they contribute to acute erythrocytic-stage pathology, it became apparent that a classical Th2 response producing IL-4 is not a critical feature of the CD4+ T-cell response during the chronic phase of infection. Rather, effective CD4+ T-cell help for B-cells, which can occur in the absence of IL-4, is required to control chronic parasitemia. IL-10, important to counterbalance inflammation and associated with protection from inflammatory-mediated severe malaria in both humans and experimental models, was originally considered be produced by CD4+ Th2 cells during infection. We review the interpretations of CD4+ T-cell responses during Plasmodium infection, proposed under the original Th1/Th2 paradigm, in light of more recent advances, including the identification of multifunctional T-cells such as Th1 cells co-expressing IFN-γ and IL-10, the identification of follicular helper T-cells (Tfh) as the predominant CD4+ T helper subset for B-cells, and the recognition of inherent plasticity in the fates of different CD4+ T-cells. PMID:25628621

  9. Regulation of T Cell Receptor Signaling by DENND1B in TH2 Cells and Allergic Disease.

    PubMed

    Yang, Chiao-Wen; Hojer, Caroline D; Zhou, Meijuan; Wu, Xiumin; Wuster, Arthur; Lee, Wyne P; Yaspan, Brian L; Chan, Andrew C

    2016-01-14

    The DENN domain is an evolutionary conserved protein module found in all eukaryotes and serves as an exchange factor for Rab-GTPases to regulate diverse cellular functions. Variants in DENND1B are associated with development of childhood asthma and other immune disorders. To understand how DENND1B may contribute to human disease, Dennd1b(-/-) mice were generated and exhibit hyper-allergic responses following antigen challenge. Dennd1b(-/-) TH2, but not other TH cells, exhibit delayed receptor-induced T cell receptor (TCR) downmodulation, enhanced TCR signaling, and increased production of effector cytokines. As DENND1B interacts with AP-2 and Rab35, TH2 cells deficient in AP-2 or Rab35 also exhibit enhanced TCR-mediated effector functions. Moreover, human TH2 cells carrying asthma-associated DENND1B variants express less DENND1B and phenocopy Dennd1b(-/-) TH2 cells. These results provide a molecular basis for how DENND1B, a previously unrecognized regulator of TCR downmodulation in TH2 cells, contributes to asthma pathogenesis and how DENN-domain-containing proteins may contribute to other human disorders.

  10. Ex vivo rapamycin generates donor Th2 cells that potently inhibit graft-versus-host disease and graft-versus-tumor effects via an IL-4-dependent mechanism.

    PubMed

    Foley, Jason E; Jung, Unsu; Miera, Angel; Borenstein, Todd; Mariotti, Jacopo; Eckhaus, Michael; Bierer, Barbara E; Fowler, Daniel H

    2005-11-01

    Rapamycin (sirolimus) inhibits graft-vs-host disease (GVHD) and polarizes T cells toward Th2 cytokine secretion after allogeneic bone marrow transplantation (BMT). Therefore, we reasoned that ex vivo rapamycin might enhance the generation of donor Th2 cells capable of preventing GVHD after fully MHC-disparate murine BMT. Using anti-CD3 and anti-CD28 costimulation, CD4+ Th2 cell expansion was preserved partially in high-dose rapamycin (10 microM; Th2.rapa cells). Th2.rapa cells secreted IL-4 yet had reduced IL-5, IL-10, and IL-13 secretion relative to control Th2 cells. BMT cohorts receiving wild-type (WT) Th2.rapa cells, but not Th2.rapa cells generated from IL-4-deficient (knockout) donors, had marked Th2 skewing post-BMT and greatly reduced donor anti-host T cell alloreactivity. Histologic studies demonstrated that Th2.rapa cell recipients had near complete abrogation of skin, liver, and gut GVHD. Overall survival in recipients of WT Th2.rapa cells, but not IL-4 knockout Th2.rapa cells, was constrained due to marked attenuation of an allogeneic graft-vs-tumor (GVT) effect against host-type breast cancer cells. Delay in Th2.rapa cell administration until day 4, 7, or 14 post-BMT enhanced GVT effects, moderated GVHD, and improved overall survival. Therefore, ex vivo rapamycin generates enhanced donor Th2 cells for attempts to balance GVHD and GVT effects.

  11. Lipooligosaccharide from Bordetella pertussis induces mature human monocyte-derived dendritic cells and drives a Th2 biased response.

    PubMed

    Fedele, Giorgio; Celestino, Ignacio; Spensieri, Fabiana; Frasca, Loredana; Nasso, Maria; Watanabe, Mineo; Remoli, Maria Elena; Coccia, Eliana Marina; Altieri, Fabio; Ausiello, Clara Maria

    2007-06-01

    Bordetella pertussis has a distinctive cell wall lipooligosaccharide (LOS) that is released from the bacterium during bacterial division and killing. LOS directly participates in host-bacterial interactions, in particular influencing the dendritic cells' (DC) immune regulatory ability. We analyze LOS mediated toll-like receptor (TLR) activation and dissect the role played by LOS on human monocyte-derived (MD)DC functions and polarization of the host T cell response. LOS activates TLR4-dependent signaling and induces mature MDDC able to secrete IL-10. LOS-matured MDDC enhance allogeneic presentation and skew T helper (Th) cell polarization towards a Th2 phenotype. LOS protects MDDC from undergoing apoptosis, prolonging their longevity and their functions. Compared to Escherichia coli lipopolysaccharide (LPS), the classical DC maturation stimulus, LOS was a less efficient inducer of TLR4 signaling, MDDC maturation, IL-10 secretion and allogeneic T cell proliferation and it was not able to induce IL-12p70 production in MDDC. However, the MDDC apoptosis protection exerted by LOS and LPS were comparable. In conclusion, LOS treated MDDC are able to perform antigen presentation in a context that promotes licensing of Th2 effectors. Considering these properties, the use of LOS in the formulation of acellular pertussis vaccines to potentiate protective and adjuvant capacity should be taken into consideration.

  12. T helper 2 (Th2) T cells induce acute pancreatitis and diabetes in immune-compromised nonobese diabetic (NOD) mice.

    PubMed

    Pakala, S V; Kurrer, M O; Katz, J D

    1997-07-21

    Autoimmune diabetes is caused by the CD4(+), T helper 1 (Th1) cell-mediated apoptosis of insulin-producing beta cells. We have previously shown that Th2 T cells bearing the same T cell receptor (TCR) as the diabetogenic Th1 T cells invade islets in neonatal nonobese diabetic (NOD) mice but fail to cause disease. Moreover, when mixed in excess and cotransferred with Th1 T cells, Th2 T cells could not protect NOD neonates from Th1-mediated diabetes. We have now found, to our great surprise, the same Th2 T cells that produced a harmless insulitis in neonatal NOD mice produced intense and generalized pancreatitis and insulitis associated with islet cell necrosis, abscess formation, and subsequent diabetes when transferred into immunocompromised NOD.scid mice. These lesions resembled allergic inflamation and contained a large eosinophilic infiltrate. Moreover, the Th2-mediated destruction of islet cells was mediated by local interleukin-10 (IL-10) production but not by IL-4. These findings indicate that under certain conditions Th2 T cells may not produce a benign or protective insulitis but rather acute pathology and disease. Additionally, these results lead us to question the feasibility of Th2-based therapy in type I diabetes, especially in immunosuppressed recipients of islet cell transplants.

  13. Effect of Th1/Th2 cytokine administration on proinflammatory SKOV-3 cell activation

    PubMed Central

    Sikora, Justyna; Kondera-Anasz, Zdzisława; Mickiewicz, Patrycja; Mickiewicz, Adam

    2015-01-01

    Introduction Interleukin(IL)-1β, IL-6 and IL-12 might associate with inflammatory processes in a tumor progression and create a specific microenvironment for tumor growth. The aim of the study was to assess whether the Th1 and Th2 type cytokines, such as IL-2 and IL-10, affect ovarian carcinoma continuous cell line (SKOV-3) pro-inflammatory activation. Material and methods SKOV-3 ovarian cells and peripheral blood mononuclear cells (PBMCs) were stimulated by IL-2 and IL-10. Additionally, SKOV-3 ovarian cells and PBMCs were co-cultured together. Proinflammatory activation of cancer cells was evaluated by measurement of IL-1β and IL-6 levels in culture fluid after 72 h of incubation. Results SKOV-3 cells and PBMCs secreted IL-1β and IL-6. After stimulation by IL-2 and IL-10, secretion of studied parameters was changed in a dose-dependent manner. The addition of a higher IL-2 level gave rise to an increase of IL-1β, IL-6 and IL-12 secretion in SKOV-3 cells. Stimulation by IL-10 increased only IL-1β secretion in SKOV-3 cells. However, IL-6 secretion decreased after stimulation with 25 ng/ml IL-10. Activatory effects of IL-2 and inhibitory effects of IL-10 in co-culture of SKOV-3 and PBMCs were observed. Conclusions Our results suggested that Th1/Th2 type of cytokines might influence pro-inflammatory activation of SKOV-3 ovarian cells. Co-cultures of SKOV-3 and PBMCs showed significant changes in cross-talk between cancer and immune cells. PMID:27904527

  14. Th1 and Th2 cytokine profiles in sickle cell disease.

    PubMed

    Raghupathy, R; Haider, M Z; Azizieh, F; Abdelsalam, R; D'Souza, T M; Adekile, A D

    2000-01-01

    We have investigated the levels of Th1 (IL-2 and IFN-gamma) and Th2 (IL-4) cytokines in the plasma and supernatants following peripheral blood mononuclear cell culture and mitogen stimulation in a group of 39 patients with sickle cell disease (SCD) made up of 29 SS, 8 Sbeta-thal and 2 Hb SD in steady state. Five SS patients were studied during 7 episodes of vaso-occlusive crisis. Twenty-four control (3 Hb AS and 21 Hb AA) were also studied; 10 were acutely ill while 14 were healthy at the time of the study. The plasma levels of IL-2 and IFN-gamma were similar in the patients and the controls. However, plasma IL-4 was significantly higher among the steady-state SS patients than in the controls. While there was no significant difference in cytokine levels following mitogen stimulation in the different groups, plasma IL-2 to IL-4 and IFN-gamma to IL-4 ratios were significantly lower among the steady-state SS patients, indicating a possible Th2 bias in our sickle cell patients and suggesting a possible mechanism to explain the predisposition of SCD patients to bacterial infections. However, SS patients with good splenic function showed a relative Th1 bias, which may be an additional explanation for the protection against bacterial infections in such patients.

  15. Th2-polarized CD4+ T cells and macrophages limit efficacy of radiation therapy

    PubMed Central

    Shiao, Stephen L.; Ruffell, Brian; DeNardo, David G.; Faddegon, Bruce A.; Park, Catherine C.; Coussens, Lisa M.

    2015-01-01

    Radiation therapy (RT) and chemotherapy (CTX) following surgery are mainstays of treatment for breast cancer (BC). While multiple studies have recently revealed the significance of immune cells as mediators of CTX response in BC, less is known regarding roles for leukocytes as mediating outcomes following RT. To address this, we utilized a syngeneic orthotopic murine model of mammary carcinogenesis to investigate if response to RT could be improved when select immune cells or immune-based pathways in the mammary microenvironment were inhibited. Treatment of mammary tumor-bearing mice with either a neutralizing monoclonal antibody (mAb) to colony-stimulating factor-1 (CSF-1) or a small molecule inhibitor of the CSF-1 receptor kinase (i.e., PLX3397), resulting in efficient macrophage depletion, significantly delayed tumor regrowth following RT. Delayed tumor growth in this setting was associated with increased presence of CD8+ T cells, and reduced presence of CD4+ T cells, the main source of the Th2 cytokine interleukin (IL)4 in mammary tumors. Selective depletion of CD4+ T cells or neutralization of IL4 in combination with RT, phenocopied results following macrophage depletion, whereas depletion of CD8+ T cells abrogated improved response to RT following these therapies. Analogously, therapeutic neutralization of IL4 or IL13, or IL4 receptor alpha deficiency, in combination with the CTX paclitaxel resulted in slowed primary mammary tumor growth by CD8+ T cell-dependent mechanisms. These findings indicate that clinical responses to cytotoxic therapy in general can be improved by neutralizing dominant Th2-based programs driving protumorigenic and immune suppressive pathways in mammary (breast) tumors to improve outcomes. PMID:25716473

  16. Ascaris lumbricoides pseudocoelomic body fluid induces a partially activated dendritic cell phenotype with Th2 promoting ability in vivo.

    PubMed

    Dowling, David J; Noone, Cariosa M; Adams, Paul N; Vukman, Krisztina V; Molloy, Sile F; Forde, Jessica; Asaolu, Samuel; O'Neill, Sandra M

    2011-02-01

    Dendritic cells (DCs) matured with helminth-derived molecules that promote Th2 immune responses do not follow conventional definitions of DC maturation processes. While a number of models of DC maturation by Th2 stimuli are postulated, further studies are required if we are to clearly define DC maturation processes that lead to Th2 immune responses. In this study, we examine the interaction of Th2-inducing molecules from the parasitic helminth Ascaris lumbricoides with the maturation processes and function of DCs. Here we show that murine bone marrow-derived DCs are partially matured by A. lumbricoides pseudocoelomic body fluid (ABF) as characterised by the production of IL-6, IL-12p40 and macrophage inflammatory protein 2 (MIP-2) but no enhanced expression of cluster of differentiation (CD)-14, T-cell co-stimulatory markers CD80, CD86, CD40, OX40L and major histocompatibility complex class II was observed. Despite these phenotypic characteristics, ABF-stimulated DCs displayed the functional hallmarks of fully matured cells, enhancing DC phagocytosis and promoting Th2-type responses in skin-draining lymph node cells in vivo. ABF activated Th2-associated extracellular signal-regulated kinase-1 and nuclear factor-kB intracellular signalling pathways independently of toll-like receptor 4. Taken together, we believe this is the first paper to demonstrate A. lumbricoides murine DC-Th cell-driven responses shedding further light on DC maturation processes by helminth antigens.

  17. The autophagy gene Atg16l1 differentially regulates Treg and TH2 cells to control intestinal inflammation

    PubMed Central

    Kabat, Agnieszka M; Moghaddam, Amin E; Pearson, Claire F; Laing, Adam; Abeler-Dörner, Lucie; Forman, Simon P; Grencis, Richard K; Sattentau, Quentin; Simon, Anna Katharina; Pott, Johanna; Maloy, Kevin J

    2016-01-01

    A polymorphism in the autophagy gene Atg16l1 is associated with susceptibility to inflammatory bowel disease (IBD); however, it remains unclear how autophagy contributes to intestinal immune homeostasis. Here, we demonstrate that autophagy is essential for maintenance of balanced CD4+ T cell responses in the intestine. Selective deletion of Atg16l1 in T cells in mice resulted in spontaneous intestinal inflammation that was characterized by aberrant type 2 responses to dietary and microbiota antigens, and by a loss of Foxp3+ Treg cells. Specific ablation of Atg16l1 in Foxp3+ Treg cells in mice demonstrated that autophagy directly promotes their survival and metabolic adaptation in the intestine. Moreover, we also identify an unexpected role for autophagy in directly limiting mucosal TH2 cell expansion. These findings provide new insights into the reciprocal control of distinct intestinal TH cell responses by autophagy, with important implications for understanding and treatment of chronic inflammatory disorders. DOI: http://dx.doi.org/10.7554/eLife.12444.001 PMID:26910010

  18. Blood myeloid and lymphoid dendritic cells reflect Th1/Th2 balance in sarcoidosis and extrinsic allergic alveolitis.

    PubMed

    Buczkowski, Jarosław; Krawczyk, Paweł; Chocholska, Sylwia; Tabarkiewicz, Jacek; Kieszko, Robert; Michnar, Marek; Milanowski, Janusz; Roliński, Jacek

    2003-01-01

    Dendritic cells play a specific regulatory role in the immune system. In this paper, the significance of myeloid and lymphoid dendritic cells in sarcoidosis and extrinsic allergic alveolitis (EAA) was evaluated. Myeloid dendritic cells are connected with Th1 type of immunological response, whereas lymphoid ones--with Th2 type. The latest findings indicate that both diseases are characterized by serious disturbances of Th1/Th2 response to Th1 dominance. Our studies seem to confirm these suggestions. In the peripheral blood of patients with sarcoidosis as well as with EAA, myeloid dendritic cells outnumbered lymphoid ones.

  19. Myeloid dendritic cells stimulated by thymic stromal lymphopoietin promote Th2 immune responses and the pathogenesis of oral lichen planus

    PubMed Central

    Hayashida, Jun-Nosuke; Maehara, Takashi; Ishiguro, Noriko; Kubota, Keigo; Furukawa, Sachiko; Ohta, Miho; Sakamoto, Mizuki; Tanaka, Akihiko; Nakamura, Seiji

    2017-01-01

    Oral lichen planus (OLP) is a chronic inflammatory disease characterized by subepithelial T-cell infiltration. Recent studies reported that specific T helper (Th) subsets, especially Th2 cells, are involved in the pathogenesis of OLP. Thymic stromal lymphopoietin (TSLP) is mainly secreted by epithelial cells and potently activates myeloid dendritic cells (mDCs) to induce Th2-mediated inflammation. Here, we investigated the expression of TSLP and related molecules in OLP. Buccal mucosa specimens from patients with OLP, hyperkeratosis, and ulcer were analyzed by immunohistochemistry for expression of TSLP, its receptor (TSLPR), and inflammatory cells. TSLP was detected in/around the epithelium of patients with OLP and hyperkeratosis, whereas TSLPR, CD11c (mDC), and GATA3 (Th2) were strongly expressed in the subepithelial layer only in OLP patients. Double immunofluorescence staining showed that TSLPR expression mainly co-localized with CD11c. Moreover, the number of CD11c- and GATA-3 positive cells was correlated in OLP patients. In lesions selectively extracted by laser microdissection, the mRNA expression of Th2 (IL-4, MDC, TARC, GATA3)- and Th17 (IL-17, RORγt)-related molecules in OLP patients was significantly higher than in other groups. These results suggest that CD11c+ mDCs expressing TSLPR contribute to aberrant Th2 immune responses and the pathogenesis of OLP via TSLP stimulation. PMID:28278185

  20. STAT4-mediated transcriptional repression of the IL5 gene in human memory Th2 cells.

    PubMed

    Gonzales-van Horn, Sarah R; Estrada, Leonardo D; van Oers, Nicolai S C; Farrar, J David

    2016-06-01

    Type I interferon (IFN-α/β) plays a critical role in suppressing viral replication by driving the transcription of hundreds of interferon-sensitive genes (ISGs). While many ISGs are transcriptionally activated by the ISGF3 complex, the significance of other signaling intermediates in IFN-α/β-mediated gene regulation remains elusive, particularly in rare cases of gene silencing. In human Th2 cells, IFN-α/β signaling suppressed IL5 and IL13 mRNA expression during recall responses to T-cell receptor (TCR) activation. This suppression occurred through a rapid reduction in the rate of nascent transcription, independent of de novo expression of ISGs. Further, IFN-α/β-mediated STAT4 activation was required for repressing the human IL5 gene, and disrupting STAT4 dimerization reversed this effect. This is the first demonstration of STAT4 acting as a transcriptional repressor in response to IFN-α/β signaling and highlights the unique activity of this cytokine to acutely block the expression of an inflammatory cytokine in human T cells.

  1. Th2-Associated Alternative Kupffer Cell Activation Promotes Liver Fibrosis without Inducing Local Inflammation

    PubMed Central

    López-Navarrete, Giuliana; Ramos-Martínez, Espiridión; Suárez-Álvarez, Karina; Aguirre-García, Jesús; Ledezma-Soto, Yadira; León-Cabrera, Sonia; Gudiño-Zayas, Marco; Guzmán, Carolina; Gutiérrez-Reyes, Gabriela; Hernández-Ruíz, Joselín; Camacho-Arroyo, Ignacio; Robles-Díaz, Guillermo; Kershenobich, David; Terrazas, Luis I.; Escobedo, Galileo

    2011-01-01

    Cirrhosis is the final outcome of liver fibrosis. Kupffer cell-mediated hepatic inflammation is considered to aggravate liver injury and fibrosis. Alternatively-activated macrophages are able to control chronic inflammatory events and trigger wound healing processes. Nevertheless, the role of alternative Kupffer cell activation in liver harm is largely unclear. Thus, we evaluated the participation of alternatively-activated Kupffer cells during liver inflammation and fibrosis in the murine model of carbon tetrachloride-induced hepatic damage. To stimulate alternative activation in Kupffer cells, 20 Taenia crassiceps (Tc) larvae were inoculated into BALBc/AnN female mice. Six weeks post-inoculation, carbon tetrachloride or olive oil were orally administered to Tc-inoculated and non-inoculated mice twice per week during other six weeks. The initial exposure of animals to T. crassiceps resulted in high serum concentrations of IL-4 accompanied by a significant increase in the hepatic mRNA levels of Ym-1, with no alteration in iNOS expression. In response to carbon tetrachloride, recruitment of inflammatory cell populations into the hepatic parenchyma was 5-fold higher in non-inoculated animals than Tc-inoculated mice. In contrast, carbon tetrachloride-induced liver fibrosis was significantly less in non-inoculated animals than in the Tc-inoculated group. The latter showed elevated IL-4 serum levels and low IFN-γ concentrations during the whole experiment, associated with hepatic expression of IL-4, TGF-β, desmin and α-sma, as well as increased mRNA levels of Arg-1, Ym-1, FIZZ-1 and MMR in Kupffer cells. These results suggest that alternative Kupffer cell activation is favored in a Th2 microenvironment, whereby such liver resident macrophages could exhibit a dichotomic role during chronic hepatic damage, being involved in attenuation of the inflammatory response but at the same time exacerbation of liver fibrosis. PMID:22110380

  2. NK cell deficiency predisposes to viral-induced Th2-type allergic inflammation via epithelial-derived IL-25.

    PubMed

    Kaiko, Gerard E; Phipps, Simon; Angkasekwinai, Pornpimon; Dong, Chen; Foster, Paul S

    2010-10-15

    Severe respiratory syncytial virus (RSV) infection has long been associated with an increased risk for the development of childhood asthma and exacerbations of this disorder. Despite much research into the induction of Th2 responses by allergens and helminths, the factors associated with viral infection that predispose to Th2-regulated asthma remain unknown. Recently, clinical studies have shown reduced numbers of NK cells in infants suffering from a severe RSV infection. Here we demonstrate that NK cell deficiency during primary RSV infection of BALB/c mice results in the suppression of IFN-γ production and the development of an RSV-specific Th2 response and subsequent allergic lung disease. The outgrowth of the Th2 responses was dependent on airway epithelial cell-derived IL-25, which induced the upregulation of the notch ligand Jagged1 on dendritic cells. This study identifies a novel pathway underlying viral-driven Th2 responses that may have functional relevance to viral-associated asthma.

  3. Behavior of  Visceral Leishmania donovani in an Experimentally Induced T Helper Cell 2 (Th2)-Associated Response Model

    PubMed Central

    Murray, Henry W.; Hariprashad, June; Coffman, Robert L.

    1997-01-01

    Although implicated in the clinical expression of human visceral leishmaniasis, a disease-exacerbating T helper cell 2 (Th2)-associated immune response involving interleukin-4 (IL-4) and/ or IL-10 is not readily detectable in experimental visceral infection. To overcome this obstacle to analyzing visceral Leishmania donovani in this relevant immunopathogenetic environment, we sought a model in which a Th2 response induces noncuring infection. Four initial approaches were tested primarily in BALB/c mice which control intracellular L. donovani via an IL-12– and interferon-γ (IFN-γ)–dependent Th1 mechanism: (a) modifying the cytokine milieu when the parasite is first encountered (treatment with exogenous IL-4 or anti–IL-12), (b) providing sustained endogenous exposure to a Th2 cytokine (infection of IL-4 transgenic mice), (c) increasing the parasite challenge inoculum, and (d) injecting heat-killed L. major promastigotes (HKLMP) to induce a cross-reactive Th2 response to live L. donovani. Only the last approach generated a functional Th2-type response that induced disease exacerbation accompanied by inhibition of tissue granuloma assembly. In HKLMP-primed BALB/c mice, prophylaxis with anti–IL-4, anti–IL-10, or exogenous IL-12 (but not IFN-γ) readily restored resistance. In primed mice with established visceral infection, treatment with either IL-12 or IFN-γ also successfully induced antileishmanial activity. The results in this model (a) suggest that rather than acting alone, IL-4 and IL-10 may act in concert to prevent acquisition of resistance to L. donovani, (b) reemphasize the capacity of IL-12 to reverse early Th2-related effects, and (c) demonstrate that Th1 cytokines (IL-12, IFN-γ) have therapeutic action in an established systemic infection despite the presence of a disease-exacerbating Th2-type response. PMID:9120392

  4. Schistosome-induced pulmonary B cells inhibit allergic airway inflammation and display a reduced Th2-driving function.

    PubMed

    van der Vlugt, L E; Obieglo, K; Ozir-Fazalalikhan, A; Sparwasser, T; Haeberlein, S; Smits, H H

    2017-04-04

    Chronic schistosome infections protect against allergic airway inflammation (AAI) via the induction of IL-10-producing splenic regulatory B (Breg) cells. Previous experiments have demonstrated that schistosome-induced pulmonary B cells can also reduce AAI, but act independently of IL-10. We have now further characterized the phenotype and inhibitory activity of these protective pulmonary B cells. We excluded a role for regulatory T (Treg) cell induction as putative AAI-protective mechanisms. Schistosome-induced B cells showed increased CD86 expression and reduced cytokine expression in response to Toll-like receptor (TLR) ligands compared with control B cells. To investigate the consequences for T cell activation we cultured ovalbumin (OVA)-pulsed, schistosome-induced B cells with OVA-specific transgenic T cells and observed less Th2 cytokine expression and T cell proliferation compared with control conditions. This suppressive effect was preserved even under optimal T cell stimulation by anti-CD3/28. Blocking of the inhibitory cytokines IL-10 or TGF-β only marginally restored Th2 cytokine induction. These data suggest that schistosome-induced pulmonary B cells are impaired in their capacity to produce cytokines to TLR ligands and to induce Th2 cytokine responses independent of their antigen-presenting function. These findings underline the presence of distinct B cell subsets with different stimulatory or inhibitory properties even if induced by the same type of helminth.

  5. Mast cells play a key role in Th2 cytokine-dependent asthma model through production of adhesion molecules by liberation of TNF-α.

    PubMed

    Chai, Ok Hee; Han, Eui-Hyeog; Lee, Hern-Ku; Song, Chang Ho

    2011-01-31

    Mast cells are well recognized as key cells in allergic reactions, such as asthma and allergic airway diseases. However, the effects of mast cells and TNF-α on T-helper type 2 (Th2) cytokine-dependent asthma are not clearly understood. Therefore, an aim of this study was to investigate the role of mast cells on Th2 cytokine-dependent airway hyperresponsiveness and inflammation. We used genetically mast cell-deficient WBB6F1/J-Kitw/Kitw-v (W/Wv), congenic normal WBB6F1/J-Kit+/Kit+ (+/+), and mast cell-reconstituted W/Wv mouse models of allergic asthma to investigate the role of mast cells in Th2 cytokine-dependent asthma induced by ovalbumin (OVA). And we investigated whether the intratracheal injection of TNF-α directly induce the expression of ICAM-1 and VCAM-1 in W/Wv mice. This study, with OVA-sensitized and OVA-challenged mice, revealed the following typical histopathologic features of allergic diseases: increased inflammatory cells of the airway, airway hyperresponsiveness, and increased levels of TNF-α, intercellular adhesion molecule (ICAM)-1, and vascular cellular adhesion molecule (VCAM)-1. However, the histopathologic features and levels of ICAM-1 and VCAM-1 proteins in W/Wv mice after OVA challenges were significantly inhibited. Moreover, mast cell-reconstituted W/Wv mice showed restoration of histopathologic features and recovery of ICAM-1 and VCAM-1 protein levels that were similar to those found in +/+ mice. Intratracheal administration of TNF-α resulted in increased ICAM-1 and VCAM-1 protein levels in W/Wv mice. These results suggest that mast cells play a key role in a Th2 cytokine-dependent asthma model through production of adhesion molecules, including ICAM-1 and VCAM-1, by liberation of TNF-α.

  6. Hyperreactive onchocerciasis is characterized by a combination of Th17-Th2 immune responses and reduced regulatory T cells.

    PubMed

    Katawa, Gnatoulma; Layland, Laura E; Debrah, Alex Y; von Horn, Charlotte; Batsa, Linda; Kwarteng, Alexander; Arriens, Sandra; W Taylor, David; Specht, Sabine; Hoerauf, Achim; Adjobimey, Tomabu

    2015-01-01

    Clinical manifestations in onchocerciasis range from generalized onchocerciasis (GEO) to the rare but severe hyperreactive (HO)/sowda form. Since disease pathogenesis is associated with host inflammatory reactions, we investigated whether Th17 responses could be related to aggravated pathology in HO. Using flow cytometry, filarial-specific cytokine responses and PCR arrays, we compared the immune cell profiles, including Th subsets, in individuals presenting the two polar forms of infection and endemic normals (EN). In addition to elevated frequencies of memory CD4+ T cells, individuals with HO showed accentuated Th17 and Th2 profiles but decreased CD4+CD25hiFoxp3+ regulatory T cells. These profiles included increased IL-17A+, IL-4+, RORC2+ and GATA3+CD4+ T cell populations. Flow cytometry data was further confirmed using a PCR array since Th17-related genes (IL-17 family members, IL-6, IL-1β and IL-22) and Th2-related (IL-4, IL-13, STAT6) genes were all significantly up-regulated in HO individuals. In addition, stronger Onchocerca volvulus-specific Th2 responses, especially IL-13, were observed in vitro in hyperreactive individuals when compared to GEO or EN groups. This study provides initial evidence that elevated frequencies of Th17 and Th2 cells form part of the immune network instigating the development of severe onchocerciasis.

  7. Effects of strenuous exercise on Th1/Th2 gene expression from human peripheral blood mononuclear cells of marathon participants.

    PubMed

    Xiang, Lianbin; Rehm, Kristina E; Marshall, Gailen D

    2014-08-01

    Physical stressors, such as strenuous exercise, can have numerous effects on the human body including the immune system. The aim of this study was to evaluate the gene expression profile of Th1/Th2 cytokines and related transcription factor genes in order to investigate possible immune imbalances before and after a marathon. Blood samples were collected from 16 normal volunteers 24-48 h before and one week after completing a marathon race. Gene expression of Th1 and Th2 related cytokines from human peripheral blood mononuclear cells (PBMC) was analyzed using Human Th1-Th2-Th3 RT(2) Profiler PCR Array and qRT-PCR that measured the transcript levels of 84 genes related to T cell activation. We found that PBMC express a characteristic Th2-like gene profile one week post-marathon compared to pre-marathon. The majority of genes up-regulated one week post-marathon such as IL-4, GATA3, and CCR4 were Th2 associated. For Th1-related genes, CXCR3 and IRF1 were up-regulated one week post-marathon. There was a trend of down-regulation of two Th1 related genes, T-bet and STAT1. Th3-related gene expression patterns did not change in the study. The ratios of both IFN-γ/IL-4 and T-bet/GATA3 gene expressions were significantly lower one week after marathon. These findings suggest that a Th1/Th2 immune imbalance persisted at least 1 week after completion of a marathon which offers a mechanistic rationale for the increased risk of upper respiratory tract infections often reported after strenuous exercise.

  8. IL-25 promotes Th2 immunity responses in airway inflammation of asthmatic mice via activation of dendritic cells.

    PubMed

    Hongjia, Li; Caiqing, Zhang; Degan, Lu; Fen, Liu; Chao, Wang; Jinxiang, Wu; Liang, Dong

    2014-08-01

    Allergic asthma occurs as a consequence of inappropriate immunologic inflammation to allergens and characterized by Th2 adaptive immune response. Recent studies indicated that interleukin (IL)-25, a member of the IL-17 cytokine family, had been implicated in inducing Th2 cell-dependent inflammation in airway epithelium and IL-25-deficient mice exhibit impaired Th2 immunity responses; however, how these cytokines influence innate immune responses remains poorly understood. In this study, we used ovalbumin (OVA) sensitization and challenge to induce the murine asthmatic model and confirmed by histological analysis of lung tissues and serum levels of total and OVA-specific immunoglobulin (Ig)-E. The expression of IL-25 was detected by quantitative real-time PCR and immunohistochemistry, respectively, and the dendritic cells (DCs) activation was detected by levels of CD80 and CD86 in bronchoalveolar lavage fluid (BALF) by flow cytometry. The mice sensitized and challenged with OVA showed high expression of IL-25 in both mRNA and protein levels in lungs. We detected the expression of CD80 and CD86 in BALF was also increased. A tight correlation between IL-25 mRNA and other Th2 cells producing cytokines such as IL-4, IL-5, and IL-13 in BALF was identified. Furthermore, when the asthmatic mice were treated with inhaled corticosteroids, the inflammatory cells infiltration and the inflammatory cytokines secretion were significantly decreased. In this study, we show that IL-25 promoted the accumulation of co-stimulatory molecules of CD80 and CD86 on DCs and then induced the differentiation of prime naive CD4(+) T cells to become proinflammatory Th2 cells and promoted Th2 cytokine responses in OVA-induced airway inflammation. The ability of IL-25 to promote the activation and differentiation of DCs population was identified as a link between the IL-17 cytokine family and the innate immune response and suggested a previously unrecognized innate immune pathway that promotes Th2

  9. A dominant role for the methyl-CpG-binding protein Mbd2 in controlling Th2 induction by dendritic cells

    PubMed Central

    Cook, Peter C.; Owen, Heather; Deaton, Aimée M.; Borger, Jessica G.; Brown, Sheila L.; Clouaire, Thomas; Jones, Gareth-Rhys; Jones, Lucy H.; Lundie, Rachel J.; Marley, Angela K.; Morrison, Vicky L.; Phythian-Adams, Alexander T.; Wachter, Elisabeth; Webb, Lauren M.; Sutherland, Tara E.; Thomas, Graham D.; Grainger, John R.; Selfridge, Jim; McKenzie, Andrew N. J.; Allen, Judith E.; Fagerholm, Susanna C.; Maizels, Rick M.; Ivens, Alasdair C.; Bird, Adrian; MacDonald, Andrew S.

    2015-01-01

    Dendritic cells (DCs) direct CD4+ T-cell differentiation into diverse helper (Th) subsets that are required for protection against varied infections. However, the mechanisms used by DCs to promote Th2 responses, which are important both for immunity to helminth infection and in allergic disease, are currently poorly understood. We demonstrate a key role for the protein methyl-CpG-binding domain-2 (Mbd2), which links DNA methylation to repressive chromatin structure, in regulating expression of a range of genes that are associated with optimal DC activation and function. In the absence of Mbd2, DCs display reduced phenotypic activation and a markedly impaired capacity to initiate Th2 immunity against helminths or allergens. These data identify an epigenetic mechanism that is central to the activation of CD4+ T-cell responses by DCs, particularly in Th2 settings, and reveal methyl-CpG-binding proteins and the genes under their control as possible therapeutic targets for type-2 inflammation. PMID:25908537

  10. B cells play key roles in th2-type airway immune responses in mice exposed to natural airborne allergens.

    PubMed

    Drake, Li Yin; Iijima, Koji; Hara, Kenichiro; Kobayashi, Takao; Kephart, Gail M; Kita, Hirohito

    2015-01-01

    Humans are frequently exposed to various airborne allergens. In addition to producing antibodies, B cells participate in immune responses via various mechanisms. The roles of B cells in allergic airway inflammation and asthma have been controversial. We examined the functional importance of B cells in a mouse model of asthma, in which mice were exposed repeatedly to common airborne allergens. Naïve wild-type BALB/c mice or B cell-deficient JH-/- mice were exposed intranasally to a cocktail of allergen extracts, including Alternaria, Aspergillus, and house dust mite, every other day for two weeks. Ovalbumin was included in the cocktail to monitor the T cell immune response. Airway inflammation, lung pathology, and airway reactivity were analyzed. The airway exposure of naïve wild type mice to airborne allergens induced robust eosinophilic airway inflammation, increased the levels of Th2 cytokines and chemokines in the lung, and increased the reactivity to inhaled methacholine. These pathological changes and immune responses were attenuated in B cell-deficient JH-/- mice. The allergen-induced expansion of CD4+ T cells was impaired in the lungs and draining lymph nodes of JH-/- mice. Furthermore, lymphocytes from JH-/- mice failed to produce Th2 cytokines in response to ovalbumin re-stimulation in vitro. Our results suggest that B cells are required for the optimal development of Th2-type immune responses and airway inflammation when exposed to common airborne allergens. The therapeutic targeting of B cells may be beneficial to treat asthma in certain patients.

  11. Ribavirin exerts differential effects on functions of Cd4+ Th1, Th2, and regulatory T cell clones in hepatitis C.

    PubMed

    Langhans, Bettina; Nischalke, Hans Dieter; Arndt, Simone; Braunschweiger, Ingrid; Nattermann, Jacob; Sauerbruch, Tilman; Spengler, Ulrich

    2012-01-01

    Ribavirin improves outcomes of therapy in chronic hepatitis C but its mode of action has still remained unclear. Since ribavirin has been proposed to modulate the host's T cell responses, we studied its direct effects on CD4(+) T cell clones with diverse functional polarization which had been generated from patients with chronic hepatitis C. We analysed in vitro proliferation ([(3)H] thymidine uptake) and cytokine responses (IL-10, IFN-gamma) at varying concentrations of ribavirin (0-10 µg/ml) in 8, 9 and 7 CD4(+) TH1, TH2 and regulatory T cell (Treg) clones, respectively. In co-culture experiments, we further determined effects of ribarivin on inhibition of TH1 and TH2 effector cells by Treg clones. All clones had been generated from peripheral blood of patients with chronic hepatitis C in the presence of HCV core protein. Ribavirin enhanced proliferation of T effector cells and increased production of IFN-gamma in TH1 clones, but had only little effect on IL-10 secretion in TH2 clones. However, ribavirin markedly inhibited IL-10 release in Treg clones in a dose dependent fashion. These Treg clones suppressed proliferation of T effector clones by their IL-10 secretion, and in co-culture assays ribavirin reversed Treg-mediated suppression of T effector cells. Our in vitro data suggest that--in addition to its immunostimulatory effects on TH1 cells--ribavirin can inhibit functions of HCV-specific Tregs and thus reverses Treg-mediated suppression of T effector cells in chronic hepatitis C.

  12. Innate production of T(H)2 cytokines by adipose tissue-associated c-Kit(+)Sca-1(+) lymphoid cells.

    PubMed

    Moro, Kazuyo; Yamada, Taketo; Tanabe, Masanobu; Takeuchi, Tsutomu; Ikawa, Tomokatsu; Kawamoto, Hiroshi; Furusawa, Jun-Ichi; Ohtani, Masashi; Fujii, Hideki; Koyasu, Shigeo

    2010-01-28

    Innate immune responses are important in combating various microbes during the early phases of infection. Natural killer (NK) cells are innate lymphocytes that, unlike T and B lymphocytes, do not express antigen receptors but rapidly exhibit cytotoxic activities against virus-infected cells and produce various cytokines. Here we report a new type of innate lymphocyte present in a novel lymphoid structure associated with adipose tissues in the peritoneal cavity. These cells do not express lineage (Lin) markers but do express c-Kit, Sca-1 (also known as Ly6a), IL7R and IL33R. Similar lymphoid clusters were found in both human and mouse mesentery and we term this tissue 'FALC' (fat-associated lymphoid cluster). FALC Lin(-)c-Kit(+)Sca-1(+) cells are distinct from lymphoid progenitors and lymphoid tissue inducer cells. These cells proliferate in response to IL2 and produce large amounts of T(H)2 cytokines such as IL5, IL6 and IL13. IL5 and IL6 regulate B-cell antibody production and self-renewal of B1 cells. Indeed, FALC Lin(-)c-Kit(+)Sca-1(+) cells support the self-renewal of B1 cells and enhance IgA production. IL5 and IL13 mediate allergic inflammation and protection against helminth infection. After helminth infection and in response to IL33, FALC Lin(-)c-Kit(+)Sca-1(+) cells produce large amounts of IL13, which leads to goblet cell hyperplasia-a critical step for helminth expulsion. In mice devoid of FALC Lin(-)c-Kit(+)Sca-1(+) cells, such goblet cell hyperplasia was not induced. Thus, FALC Lin(-)c-Kit(+)Sca-1(+) cells are T(H)2-type innate lymphocytes, and we propose that these cells be called 'natural helper cells'.

  13. Prenatal secondhand cigarette smoke promotes Th2 polarization and impairs goblet cell differentiation and airway mucus formation.

    PubMed

    Singh, Shashi P; Gundavarapu, Sravanthi; Peña-Philippides, Juan C; Rir-Sima-ah, Jules; Mishra, Neerad C; Wilder, Julie A; Langley, Raymond J; Smith, Kevin R; Sopori, Mohan L

    2011-11-01

    Parental, particularly maternal, smoking increases the risk for childhood allergic asthma and infection. Similarly, in a murine allergic asthma model, prenatal plus early postnatal exposure to secondhand cigarette smoke (SS) exacerbates airways hyperreactivity and Th2 responses in the lung. However, the mechanism and contribution of prenatal versus early postnatal SS exposure on allergic asthma remain unresolved. To identify the effects of prenatal and/or early postnatal SS on allergic asthma, BALB/c dams and their offspring were exposed gestationally and/or 8-10 wk postbirth to filtered air or SS. Prenatal, but not postnatal, SS strongly increased methacholine and allergen (Aspergillus)-induced airway resistance, Th2 cytokine levels, and atopy and activated the Th2-polarizing pathway GATA3/Lck/ERK1/2/STAT6. Either prenatal and/or early postnatal SS downregulated the Th1-specific transcription factor T-bet and, surprisingly, despite high levels of IL-4/IL-13, dramatically blocked the allergen-induced mucous cell metaplasia, airway mucus formation, and the expression of mucus-related genes/proteins: Muc5ac, γ-aminobutyric acid A receptors, and SAM pointed domain-containing Ets-like factor. Given that SS/nicotine exposure of normal adult mice promotes mucus formation, the results suggested that fetal and neonatal lung are highly sensitive to cigarette smoke. Thus, although the gestational SS promotes Th2 polarization/allergic asthma, it may also impair and/or delay the development of fetal and neonatal lung, affecting mucociliary clearance and Th1 responses. Together, this may explain the increased susceptibility of children from smoking parents to allergic asthma and childhood respiratory infections.

  14. Regulatory T cells prevent Th2 immune responses and pulmonary eosinophilia during respiratory syncytial virus infection in mice.

    PubMed

    Durant, Lydia R; Makris, Spyridon; Voorburg, Cornelia Maaike; Loebbermann, Jens; Johansson, Cecilia; Openshaw, Peter J M

    2013-10-01

    During viral infection, inflammation and recovery are tightly controlled by competing proinflammatory and regulatory immune pathways. Respiratory syncytial virus (RSV) is the leading global cause of infantile bronchiolitis, which is associated with recurrent wheeze and asthma diagnosis in later life. Th2-driven disease has been well described under some conditions for RSV-infected mice. In the present studies, we used the Foxp3(DTR) mice (which allow specific conditional depletion of Foxp3(+) T cells) to investigate the functional effects of regulatory T cells (Tregs) during A2-strain RSV infection. Infected Treg-depleted mice lost significantly more weight than wild-type mice, indicating enhanced disease. This enhancement was characterized by increased cellularity in the bronchoalveolar lavage (BAL) fluid and notable lung eosinophilia not seen in control mice. This was accompanied by abundant CD4(+) and CD8(+) T cells exhibiting an activated phenotype and induction of interleukin 13 (IL-13)- and GATA3-expressing Th2-type CD4(+) T cells that remained present in the airways even 14 days after infection. Therefore, Treg cells perform vital anti-inflammatory functions during RSV infection, suppressing pathogenic T cell responses and inhibiting lung eosinophilia. These findings provide additional evidence that dysregulation of normal immune responses to viral infection may contribute to severe RSV disease.

  15. Regulatory T Cells Prevent Th2 Immune Responses and Pulmonary Eosinophilia during Respiratory Syncytial Virus Infection in Mice

    PubMed Central

    Durant, Lydia R.; Makris, Spyridon; Voorburg, Cornelia Maaike; Loebbermann, Jens

    2013-01-01

    During viral infection, inflammation and recovery are tightly controlled by competing proinflammatory and regulatory immune pathways. Respiratory syncytial virus (RSV) is the leading global cause of infantile bronchiolitis, which is associated with recurrent wheeze and asthma diagnosis in later life. Th2-driven disease has been well described under some conditions for RSV-infected mice. In the present studies, we used the Foxp3DTR mice (which allow specific conditional depletion of Foxp3+ T cells) to investigate the functional effects of regulatory T cells (Tregs) during A2-strain RSV infection. Infected Treg-depleted mice lost significantly more weight than wild-type mice, indicating enhanced disease. This enhancement was characterized by increased cellularity in the bronchoalveolar lavage (BAL) fluid and notable lung eosinophilia not seen in control mice. This was accompanied by abundant CD4+ and CD8+ T cells exhibiting an activated phenotype and induction of interleukin 13 (IL-13)- and GATA3-expressing Th2-type CD4+ T cells that remained present in the airways even 14 days after infection. Therefore, Treg cells perform vital anti-inflammatory functions during RSV infection, suppressing pathogenic T cell responses and inhibiting lung eosinophilia. These findings provide additional evidence that dysregulation of normal immune responses to viral infection may contribute to severe RSV disease. PMID:23926350

  16. Notch-ligand expression by NALT dendritic cells regulates mucosal Th1- and Th2-type responses

    SciTech Connect

    Fukuyama, Yoshiko; Tokuhara, Daisuke; Sekine, Shinichi; Kataoka, Kosuke; Markham, Jonathan D.; Irwin, Allyson R.; Moon, Grace H.; Tokuhara, Yuka; Fujihashi, Keiko; Davydova, Julia; Yamamoto, Masato; Gilbert, Rebekah S.; Fujihashi, Kohtaro

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Nasal Ad-FL effectively up-regulates APC function by CD11c{sup +} DCs in mucosal tissues. Black-Right-Pointing-Pointer Nasal Ad-FL induces Notch ligand (L)-expressing CD11c{sup +} DCs. Black-Right-Pointing-Pointer Notch L-expressing DCs support the induction of Th1- and Th2-type cytokine responses. -- Abstract: Our previous studies showed that an adenovirus (Ad) serotype 5 vector expressing Flt3 ligand (Ad-FL) as nasal adjuvant activates CD11c{sup +} dendritic cells (DCs) for the enhancement of antigen (Ag)-specific IgA antibody (Ab) responses. In this study, we examined the molecular mechanism for activation of CD11c{sup +} DCs and their roles in induction of Ag-specific Th1- and Th2-cell responses. Ad-FL activated CD11c{sup +} DCs expressed increased levels of the Notch ligand (L)-expression and specific mRNA. When CD11c{sup +} DCs from various mucosal and systemic lymphoid tissues of mice given nasal OVA plus Ad-FL were cultured with CD4{sup +} T cells isolated from non-immunized OVA TCR-transgenic (OT II) mice, significantly increased levels of T cell proliferative responses were noted. Furthermore, Ad-FL activated DCs induced IFN-{gamma}, IL-2 and IL-4 producing CD4{sup +} T cells. Of importance, these APC functions by Ad-FL activated DCs were down-regulated by blocking Notch-Notch-L pathway. These results show that Ad-FL induces CD11c{sup +} DCs to the express Notch-ligands and these activated DCs regulate the induction of Ag-specific Th1- and Th2-type cytokine responses.

  17. Differential effects of myelin basic protein-activated Th1 and Th2 cells on the local immune microenvironment of injured spinal cord.

    PubMed

    Hu, Jian-Guo; Shi, Ling-Ling; Chen, Yue-Juan; Xie, Xiu-Mei; Zhang, Nan; Zhu, An-You; Jiang, Zheng-Song; Feng, Yi-Fan; Zhang, Chen; Xi, Jin; Lü, He-Zuo

    2016-03-01

    Myelin basic protein (MBP) activated T cells (MBP-T) play an important role in the damage and repair process of the central nervous system (CNS). However, whether these cells play a beneficial or detrimental role is still a matter of debate. Although some studies showed that MBP-T cells are mainly helper T (Th) cells, their subtypes are still not very clear. One possible explanation for MBP-T immunization leading to conflicting results may be the different subtypes of T cells are responsible for distinct effects. In this study, the Th1 and Th2 type MBP-T cells (MBP-Th1 and -Th2) were polarized in vitro, and their effects on the local immune microenvironment and tissue repair of spinal cord injury (SCI) after adoptive immunization were investigated. In MBP-Th1 cell transferred rats, the high levels of pro-inflammatory cells (Th1 cells and M1 macrophages) and cytokines (IFN-γ, TNF-α, -β, IL-1β) were detected in the injured spinal cord; however, the anti-inflammatory cells (Th2 cells, regulatory T cells, and M2 macrophages) and cytokines (IL-4, -10, and -13) were found in MBP-Th2 cell transferred animals. MBP-Th2 cell transfer resulted in decreased lesion volume, increased myelination of axons, and preservation of neurons. This was accompanied by significant locomotor improvement. These results indicate that MBP-Th2 adoptive transfer has beneficial effects on the injured spinal cord, in which the increased number of Th2 cells may alter the local microenvironment from one primarily populated by Th1 and M1 cells to another dominated by Th2, Treg, and M2 cells and is conducive for SCI repair.

  18. CD80 and CD86 knockdown in dendritic cells regulates Th1/Th2 cytokine production in asthmatic mice

    PubMed Central

    LI, JIAN-GUO; DU, YU-MO; YAN, ZHI-DONG; YAN, JIA; ZHUANSUN, YONG-XUN; CHEN, RUI; ZHANG, WEI; FENG, SU-LING; RAN, PI-XIN

    2016-01-01

    Dendritic cells (DCs) are associated with the activation and differentiation of T helper (Th) cells. Cluster of differentiation (CD)80 and CD86, the co-stimulatory molecules highly expressed in DCs, have are prominent in promoting the differentiation of Th cells toward Th2 cells. However, little is known about the effect of CD80 and CD86 knockdown on Th1/Th2 cytokine production in mature DCs (mDCs). The aim of the present study was to investigate whether small-interfering RNA (siRNA) could suppress the surface expression of CD80 and CD86 in mDCs. The effects of CD80 and CD86 knockdown in mDCs on Th1/Th2 cytokine expression were examined using an asthmatic murine model. DCs were isolated, separated and cultured in vitro. Flow cytometry was used to examine the expression of CD11c, CD80 and CD86 on the DCs. The DCs were transfected with CD80- and CD86-specific siRNA, while non-siRNA and negative siRNA controls were also designed. Then, the mRNA and protein expression levels of CD80 and CD86 were determined by reverse transcription-quantitative polymerase chain reaction and flow cytometry, respectively. The levels of interferon (IFN)-γ and interleukin (IL)-4 produced by T cells co-cultured with mDCs were measured by enzyme-linked immunosorbent assay. Substantial downregulation of CD80 and CD86 mRNA and protein levels were observed in the mDCs following transfection with siRNA. The level of IFN-γ produced by T cells co-cultured with mDCs was significantly increased in the siRNA group, while IL-4 production was significantly decreased. These results show that specific targeting of CD80 and CD86 with siRNA is able to suppress CD80/CD86 expression and consequently regulate Th1/Th2 cytokine levels by increasing IFN-γ production and decreasing IL-4 levels in an asthmatic murine model. PMID:26998006

  19. Blockade of PD-1 Signaling Enhances Th2 Cell Responses and Aggravates Liver Immunopathology in Mice with Schistosomiasis japonica

    PubMed Central

    Zhou, Sha; Jin, Xin; Li, Yalin; Li, Wei; Chen, Xiaojun; Xu, Lei; Zhu, Jifeng; Xu, Zhipeng; Zhang, Yang; Liu, Feng; Su, Chuan

    2016-01-01

    Background More than 220 million people worldwide are chronically infected with schistosomes, causing severe disease or even death. The major pathological damage occurring in schistosomiasis is attributable to the granulomatous inflammatory response and liver fibrosis induced by schistosome eggs. The inflammatory response is tightly controlled and parallels immunosuppressive regulation, constantly maintaining immune homeostasis and limiting excessive immunopathologic damage in important host organs. It is well known that the activation of programmed death 1 (PD-1) signaling causes a significant suppression of T cell function. However, the roles of PD-1 signaling in modulating CD4+ T cell responses and immunopathology during schistosome infection, have yet to be defined. Methodology/Principal Findings Here, we show that PD-1 is upregulated in CD4+ T cells in Schistosoma japonicum (S. japonicum)-infected patients. We also show the upregulation of PD-1 expression in CD4+ T cells in the spleens, mesenteric lymph nodes, and livers of mice with S. japonicum infection. Finally, we found that the blockade of PD-1 signaling enhanced CD4+ T helper 2 (Th2) cell responses and led to more severe liver immunopathology in mice with S. japonicum infection, without a reduction of egg production or deposition in the host liver. Conclusions/Significance Overall, our study suggests that PD-1 signaling is specifically induced to control Th2-associated inflammatory responses during schistosome infection and is beneficial to the development of PD-1-based control of liver immunopathology. PMID:27792733

  20. T helper cell IL-4 drives intestinal Th2 priming to oral peanut antigen, under the control of OX40L and independent of innate-like lymphocytes.

    PubMed

    Chu, D K; Mohammed-Ali, Z; Jiménez-Saiz, R; Walker, T D; Goncharova, S; Llop-Guevara, A; Kong, J; Gordon, M E; Barra, N G; Gillgrass, A E; Van Seggelen, H; Khan, W I; Ashkar, A A; Bramson, J L; Humbles, A A; Kolbeck, R; Waserman, S; Jordana, M

    2014-11-01

    Intestinal T helper type 2 (Th2) immunity in food allergy results in IgG1 and IgE production, and antigen re-exposure elicits responses such as anaphylaxis and eosinophilic inflammation. Although interleukin-4 (IL-4) is critically required for allergic sensitization, the source and control of IL-4 during the initiation of Th2 immunity in vivo remains unclear. Non-intestinal and non-food allergy systems have suggested that natural killer-like T (NKT) or γδ T-cell innate lymphocytes can supply the IL-4 required to induce Th2 polarization. Group 2 innate lymphoid cells (ILCs) are a novel IL-4-competent population, but their contribution to initiating adaptive Th2 immunity is unclear. There are also reports of IL-4-independent Th2 responses. Here, we show that IL-4-dependent peanut allergic Th2 responses are completely intact in NKT-deficient, γδ T-deficient or ILC-deficient mice, including antigen-specific IgG1/IgE production, anaphylaxis, and cytokine production. Instead, IL-4 solely from CD4(+) Th cells induces full Th2 immunity. Further, CD4(+) Th cell production of IL-4 in vivo is dependent on OX40L, a costimulatory molecule on dendritic cells (DCs) required for intestinal allergic priming. However, both Th2 cells and ILCs orchestrated IL-13-dependent eosinophilic inflammation. Thus, intestinal Th2 priming is initiated by an autocrine/paracrine acting CD4(+) Th cell-intrinsic IL-4 program that is controlled by DC OX40L, and not by NKT, γδ T, or ILC cells.

  1. Lead effects on development and function of bone marrow-derived dendritic cells promote Th2 immune responses

    SciTech Connect

    Gao Donghong; Mondal, Tapan K.; Lawrence, David A. . E-mail: lawrencd@wadsworth.org

    2007-07-01

    Although lead (Pb) has significant effects on the development and function of macrophages, B cells, and T cells and has been suggested to promote allergic asthma in mice and humans, Pb modulation of bone marrow (BM)-derived dendritic cells (DCs) and the resultant DC effects on Th1 and Th2 development have not been examined. Accordingly, we cultured BM cells with murine granulocyte macrophage-colony stimulating factor (mGM-CSF) {+-} PbCl{sub 2}. At day 10, culture supernatant (SN) and non-adherent cells were harvested for analysis. Additionally, day 10 non-adherent BM-DCs were harvested and recultured with mGM-CSF + LPS {+-} Pb for 2 days. The day 10 Pb exposure significantly inhibited BM-DC generation, based on CD11c expression. Although fewer DCs were generated with Pb, the existing Pb-exposed DCs had significantly greater MHC-II expression than did the non-Pb-exposed DCs. However, these differences diminished upon LPS stimulation. After LPS stimulation, CD80, CD86, CD40, CD54, and MHC-II were all up-regulated on both Pb-DCs and DCs, but Pb-DCs expressed significantly less CD80 than did DCs. The CD86:CD80 ratio suggests a Pb-DC potential for Th2 cell development. After LPS stimulation, IL-6, IL-10, IL-12 (p70), and TNF-{alpha} levels significantly increased with both Pb-DCs and DCs, but Pb-DCs produced significantly less cytokines than did DCs, except for IL-10, which further supports Pb-DC preferential skewing toward type-2 immunity. In vitro studies confirm that Pb-DCs have the ability to polarize antigen-specific T cells to Th2 cells. Pb-DCs also enhanced allogeneic and autologous T cell proliferation in vitro, and in vivo studies suggested that Pb-DCs inhibited Th1 effects on humoral and cell-mediated immunity. The Pb effect was mainly on DCs, rather than on T cells, and Pb's modification of DC function appears to be the main cause of Pb's promotion of type-2-related immunity, which may relate to Pb's enhanced activation of the Erk/MAP kinase pathway.

  2. Th17 and treg cells innovate the TH1/TH2 concept and allergy research.

    PubMed

    Schmidt-Weber, C B

    2008-01-01

    Allergic reactions are caused by harmless allergens, which are recognized by the specific immune system. Allergen-specific T cells are assumed to play a key role in the sensitization phase and in immunological memory. Current immunological concepts suggest that asymptomatic T-cell memory cells also exist, tagging the allergen as harmless and preventing an inappropriate response and thus allergic symptoms. Proinflammatory T cells mediate allergic inflammation by exceeding the induction of IgE and competing with other T-cell subsets. Therefore, molecular mechanisms leading to pro- or anti-inflammatory T-cell memory cells appear as the key mechanism in allergy.

  3. Nuclear factor of activated T cells regulates the expression of interleukin-4 in Th2 cells in an all-or-none fashion.

    PubMed

    Köck, Juliana; Kreher, Stephan; Lehmann, Katrin; Riedel, René; Bardua, Markus; Lischke, Timo; Jargosch, Manja; Haftmann, Claudia; Bendfeldt, Hanna; Hatam, Farahnaz; Mashreghi, Mir-Farzin; Baumgrass, Ria; Radbruch, Andreas; Chang, Hyun-Dong

    2014-09-26

    Th2 memory lymphocytes have imprinted their Il4 genes epigenetically for expression in dependence of T cell receptor restimulation. However, in a given restimulation, not all Th cells with a memory for IL-4 expression express IL-4. Here, we show that in reactivated Th2 cells, the transcription factors NFATc2, NF-kB p65, c-Maf, p300, Brg1, STAT6, and GATA-3 assemble at the Il4 promoter in Th2 cells expressing IL-4 but not in Th2 cells not expressing it. NFATc2 is critical for assembly of this transcription factor complex. Because NFATc2 translocation into the nucleus occurs in an all-or-none fashion, dependent on complete dephosphorylation by calcineurin, NFATc2 controls the frequencies of cells reexpressing Il4, translates analog differences in T cell receptor stimulation into a digital decision for Il4 reexpression, and instructs all reexpressing cells to express the same amount of IL-4. This analog-to-digital conversion may be critical for the immune system to respond to low concentrations of antigens.

  4. A novel small compound SH-2251 suppresses Th2 cell-dependent airway inflammation through selective modulation of chromatin status at the Il5 gene locus.

    PubMed

    Suzuki, Junpei; Kuwahara, Makoto; Tofukuji, Soichi; Imamura, Masashi; Kato, Fuminori; Nakayama, Toshinori; Ohara, Osamu; Yamashita, Masakatsu

    2013-01-01

    IL-5 is a key cytokine that plays an important role in the development of pathological conditions in allergic inflammation. Identifying strategies to inhibit IL-5 production is important in order to establish new therapies for treating allergic inflammation. We found that SH-2251, a novel thioamide-related small compound, selectively inhibits the differentiation of IL-5-producing Th2 cells. SH-2251 inhibited the induction of active histone marks at the Il5 gene locus during Th2 cell differentiation. The recruitment of RNA polymerase II, and following expression of the Th2 cell-specific intergenic transcripts around the Il5 gene locus was also inhibited. Furthermore, Th2 cell-dependent airway inflammation in mice was suppressed by the oral administration of SH-2251. Gfi1, a transcriptional repressor, was identified as a downstream target molecule of SH-2251 using a DNA microarray analysis. The Gfi1 expression dramatically decreased in SH-2251-treated Th2 cells, and the SH-2251-mediated inhibition of IL-5-producing Th2 cell differentiation was restored by transduction of Gfi1. Therefore, our study unearthed SH-2251 as a novel therapeutic candidate for allergic inflammation that selectively inhibits active histone marks at the Il5 gene locus.

  5. Th1, Th2 and Th17 Effector T Cell-Induced Autoimmune Gastritis Differs in Pathological Pattern and in Susceptibility to Suppression by Regulatory T Cells

    PubMed Central

    Stummvoll, Georg H.; DiPaolo, Richard J.; Huter, Eva N.; Davidson, Todd S.; Glass, Deborah; Ward, Jerrold M.; Shevach, Ethan M.

    2008-01-01

    Th cells can be subdivided into IFNγ-secreting Th1, IL-4/IL-5 secreting Th2, and IL-17 secreting Th17 cells. We have evaluated the capacity of fully differentiated Th1, Th2, and Th17 cells derived from a mouse bearing a transgenic TCR specific for the gastric parietal cell antigen, H/K ATPase, to induce autoimmune gastritis after transfer to immunodeficient recipients. We have also determined the susceptibility of the disease induced by each of the effector T cell types to suppression by polyclonal regulatory T cells (Treg) in vivo. Each type of effector cell induced autoimmune gastritis with distinct histological patterns. Th17 cells induced the most destructive disease with cellular infiltrates composed primarily of eosinophils accompanied by high levels of serum IgE. Polyclonal Treg could suppress the capacity of Th1 cells, moderately suppress Th2 cells, but could only suppress Th17 induced disease at early time points. The major effect of the Treg was to inhibit the expansion of the effector T cells. However, effector cells isolated from protected animals were not anergic and were fully competent to proliferate and produce effector cytokines ex vivo. The strong inhibitory effect of polyclonal Treg on the capacity of some types of differentiated effector cells to induce disease provides an experimental basis for the clinical use of polyclonal Treg in the treatment of autoimmune disease in man. PMID:18641328

  6. Th1, Th2, and Th17 effector T cell-induced autoimmune gastritis differs in pathological pattern and in susceptibility to suppression by regulatory T cells.

    PubMed

    Stummvoll, Georg H; DiPaolo, Richard J; Huter, Eva N; Davidson, Todd S; Glass, Deborah; Ward, Jerrold M; Shevach, Ethan M

    2008-08-01

    Th cells can be subdivided into IFN-gamma-secreting Th1, IL-4/IL-5-secreting Th2, and IL-17-secreting Th17 cells. We have evaluated the capacity of fully differentiated Th1, Th2, and Th17 cells derived from a mouse bearing a transgenic TCR specific for the gastric parietal cell antigen, H(+)K(+)-ATPase, to induce autoimmune gastritis after transfer to immunodeficient recipients. We have also determined the susceptibility of the disease induced by each of the effector T cell types to suppression by polyclonal regulatory T cells (Treg) in vivo. Each type of effector cell induced autoimmune gastritis with distinct histological patterns. Th17 cells induced the most destructive disease with cellular infiltrates composed primarily of eosinophils accompanied by high levels of serum IgE. Polyclonal Treg could suppress the capacity of Th1 cells, could moderately suppress Th2 cells, but could suppress Th17-induced disease only at early time points. The major effect of the Treg was to inhibit the expansion of the effector T cells. However, effector cells isolated from protected animals were not anergic and were fully competent to proliferate and produce effector cytokines ex vivo. The strong inhibitory effect of polyclonal Treg on the capacity of some types of differentiated effector cells to induce disease provides an experimental basis for the clinical use of polyclonal Treg in the treatment of autoimmune disease in humans.

  7. Th1/Th2 Cytokines: An Easy Model to Study Gene Expression in Immune Cells

    PubMed Central

    González-Polo, Rosa A.; Soler, Germán; Fuentes, José M.

    2006-01-01

    This report describes a laboratory exercise that was incorporated into a Cell Biology and Molecular Biology advanced course. The exercise was made for a class size with eight students and was designed to reinforce the understanding of basic molecular biology techniques. Students used the techniques of reverse transcription and arginase activity measurement as well as nitric oxide determination to discover whether two specific genes were expressed by cytokine-stimulated dendritic cells. The experiment served as the basis for discussing the importance of differential gene expression inside the eukaryotic cell and the importance of cytokines in the immune system. PMID:17012221

  8. Multiparameter fluorescence imaging for quantification of TH-1 and TH-2 cytokines at the single-cell level

    NASA Astrophysics Data System (ADS)

    Fekkar, Hakim; Benbernou, N.; Esnault, S.; Shin, H. C.; Guenounou, Moncef

    1998-04-01

    Immune responses are strongly influenced by the cytokines following antigenic stimulation. Distinct cytokine-producing T cell subsets are well known to play a major role in immune responses and to be differentially regulated during immunological disorders, although the characterization and quantification of the TH-1/TH-2 cytokine pattern in T cells remained not clearly defined. Expression of cytokines by T lymphocytes is a highly balanced process, involving stimulatory and inhibitory intracellular signaling pathways. The aim of this study was (1) to quantify the cytokine expression in T cells at the single cell level using optical imaging, (2) and to analyze the influence of cyclic AMP- dependent signal transduction pathway in the balance between the TH-1 and TH-2 cytokine profile. We attempted to study several cytokines (IL-2, IFN-(gamma) , IL-4, IL-10 and IL-13) in peripheral blood mononuclear cells. Cells were prestimulated in vitro using phytohemagglutinin and phorbol ester for 36h, and then further cultured for 8h in the presence of monensin. Cells were permeabilized and then simple-, double- or triple-labeled with the corresponding specific fluorescent monoclonal antibodies. The cell phenotype was also determined by analyzing the expression of each of CD4, CD8, CD45RO and CD45RA with the cytokine expression. Conventional images of cells were recorded with a Peltier- cooled CCD camera (B/W C5985, Hamamatsu photonics) through an inverted microscope equipped with epi-fluorescence (Diaphot 300, Nikon). Images were digitalized using an acquisition video interface (Oculus TCX Coreco) in 762 by 570 pixels coded in 8 bits (256 gray levels), and analyzed thereafter in an IBM PC computer based on an intel pentium processor with an adequate software (Visilog 4, Noesis). The first image processing step is the extraction of cell areas using an edge detection and a binary thresholding method. In order to reduce the background noise of fluorescence, we performed an opening

  9. Th1/Th2 Cytokines: An Easy Model to Study Gene Expression in Immune Cells

    ERIC Educational Resources Information Center

    Moran, Jose M.; Gonzalez-Polo, Rosa A.; Soler, German; Fuentes, Jose M.

    2006-01-01

    This report describes a laboratory exercise that was incorporated into a Cell Biology and Molecular Biology advanced course. The exercise was made for a class size with eight students and was designed to reinforce the understanding of basic molecular biology techniques. Students used the techniques of reverse transcription and arginase activity…

  10. Breast Cancer Cell-Derived GM-CSF Licenses Regulatory Th2 Induction by Plasmacytoid Predendritic Cells in Aggressive Disease Subtypes.

    PubMed

    Ghirelli, Cristina; Reyal, Fabien; Jeanmougin, Marine; Zollinger, Raphaël; Sirven, Philémon; Michea, Paula; Caux, Christophe; Bendriss-Vermare, Nathalie; Donnadieu, Marie-Hélène; Caly, Martial; Fourchotte, Virginie; Vincent-Salomon, Anne; Sigal-Zafrani, Brigitte; Sastre-Garau, Xavier; Soumelis, Vassili

    2015-07-15

    Reciprocal interactions between tumor cells and their microenvironment vitally impact tumor progression. In this study, we show that GM-CSF produced by primary breast tumor cells induced the activation of plasmacytoid predendritic cells (pDC), a cell type critical to anti-viral immunity. pDC that expressed the GM-CSF receptor were increased in breast tumors compared with noninvolved adjacent breast tissue. Tumor-activated pDC acquired naïve CD4(+) T-cell stimulatory capacity and promoted a regulatory Th2 response. Finally, the concomitant increase of GM-CSF and pDC was significantly associated with relatively more aggressive breast cancer subtypes. Our results characterize the first tumor-derived factor that can activate pDC to promote a regulatory Th2 response, with implications for therapeutic targeting of a tumor-immune axis of growing recognition in its significance to cancer.

  11. Alteration of leucine aminopeptidase from Streptomyces septatus TH-2 to phenylalanine aminopeptidase by site-directed mutagenesis.

    PubMed

    Arima, Jiro; Uesugi, Yoshiko; Iwabuchi, Masaki; Hatanaka, Tadashi

    2005-11-01

    To tailor leucine aminopeptidase from Streptomyces septatus TH-2 (SSAP) to become a convenient biocatalyst, we are interested in Phe221 of SSAP, which is thought to interact with the side chain of the N-terminal residue of the substrate. By using saturation mutagenesis, the feasibility of altering the performance of SSAP was evaluated. The hydrolytic activities of 19 mutants were investigated using aminoacyl p-nitroanilide (pNA) derivatives as substrates. Replacement of Phe221 resulted in changes in the activities of all the mutants. Three of these mutants, F221G, F221A, and F221S, specifically hydrolyzed L-Phe-pNA, and F221I SSAP exhibited hydrolytic activity with L-Leu-pNA exceeding that of the wild type. Although the hydrolytic activities with peptide substrates decreased, the hydrolytic activities with amide and methyl ester substrates were proportional to the changes in the hydrolytic activities with pNA derivatives. Furthermore, based on a comparative kinetic study, the mechanism underlying the alteration in the preference of SSAP from leucine to phenylalanine is discussed.

  12. Burn Wound gammadelta T-Cells Support a Th2 and Th17 Immune Response

    DTIC Science & Technology

    2014-02-01

    in chronic alcoholics is associated with multiple organ dysfunction syndrome . J Trauma 2002;52:95–103. 47. Yeh FL, Lin WL, Shen HD. Changes in...GNK (0.3%; glucose/dextrose, NaCl and KCl buffer; Sigma, St Louis, MO) for 30 min- utes at 37°C in water bath shaker. Heat inactivated fetal bovine...and centrifuged at 400 g for 10 min at 4°C. The cell pellet was resuspended in RPMI containing 10% heat-inactivated fetal bovine serum (GIBCO), 50

  13. Changes in peripheral blood Th1 and Th2 cells in rat liver transplantation under different immune statuses.

    PubMed

    Yang, Z-L; Cheng, K; Sun, H G; Zou, W W; Wu, M M

    2013-12-19

    In this study, early expressions of peripheral blood Th1 and Th2 cells were documented following rat liver transplantation and related to immune status. Rats were divided into 3 groups: group A (control): syngeneic transplantation (Brown Norway (BN) → BN); group B: allogeneic transplantation + cyclosporine A (CsA); group C: allogeneic transplantation (Lewis → BN). Flow cytometry was used to analyze peripheral blood CD4(+)CD45RC percentage on days 1, 3, 5, 7, and 14 following transplantation, and were compared to graft rejection pathological grades and receptor survival times. The average survival of groups A and B exceeded 100 days, which was significantly longer than that of group C (3.56 ± 34.3 days). With the exception of the first day, rejection grades were significantly higher in groups C and B compared to group A, and group C rejection grades were significantly higher than those of group B. Three days after transplantation, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio of group C was significantly higher than that of groups A and B. In group B, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio was negatively correlated to the rejection grade (r = -0.565, P < 0.01), whereas this relationship was positive in group C (r = 0.745, P < 0.01). In conclusion, peripheral blood Th1 was highly expressed during rejection in rat liver grafts. Peripheral blood Th2 tended to increase early under rejection inhibition with CsA, and its high expression level may correlate with long-term acceptance or tolerance of transplanted livers.

  14. Neuromedin U elicits cytokine release in murine Th2-type T cell clone D10.G4.1.

    PubMed

    Johnson, Eric N; Appelbaum, Edward R; Carpenter, Donald C; Cox, Richard F; Disa, Jyoti; Foley, James J; Ghosh, Sujoy K; Naselsky, Diane P; Pullen, Mark A; Sarau, Henry M; Scheff, Samuel R; Steplewski, Klaudia M; Zaks-Zilberman, Meirav; Aiyar, Nambi

    2004-12-15

    Neuromedin U (NmU), originally isolated from porcine spinal cord and later from other species, is a novel peptide that potently contracts smooth muscle. NmU interacts with two G protein-coupled receptors designated as NmU-1R and NmU-2R. This study demonstrates a potential proinflammatory role for NmU. In a mouse Th2 cell line (D10.G4.1), a single class of high affinity saturable binding sites for (125)I-labeled NmU (K(D) 364 pM and B(max) 1114 fmol/mg protein) was identified, and mRNA encoding NmU-1R, but not NmU-2R, was present. Competition binding analysis revealed equipotent, high affinity binding of NmU isopeptides to membranes prepared from D10.G4.1 cells. Exposure of these cells to NmU isopeptides resulted in an increase in intracellular Ca(2+) concentration (EC(50) 4.8 nM for human NmU). In addition, NmU also significantly increased the synthesis and release of cytokines including IL-4, IL-5, IL-6, IL-10, and IL-13. Studies using pharmacological inhibitors indicated that maximal NmU-evoked cytokine release required functional phospholipase C, calcineurin, MEK, and PI3K pathways. These data suggest a role for NmU in inflammation by stimulating cytokine production by T cells.

  15. Mapping post-translational modifications of mammalian testicular specific histone variant TH2B in tetraploid and haploid germ cells and their implications on the dynamics of nucleosome structure.

    PubMed

    Pentakota, Satya Krishna; Sandhya, Sankaran; P Sikarwar, Arun; Chandra, Nagasuma; Satyanarayana Rao, Manchanahalli R

    2014-12-05

    Histones regulate a variety of chromatin templated events by their post-translational modifications (PTMs). Although there are extensive reports on the PTMs of canonical histones, the information on the histone variants remains very scanty. Here, we report the identification of different PTMs, such as acetylation, methylation, and phosphorylation of a major mammalian histone variant TH2B. Our mass spectrometric analysis has led to the identification of both conserved and unique modifications across tetraploid spermatocytes and haploid spermatids. We have also computationally derived the 3-dimensional model of a TH2B containing nucleosome in order to study the spatial orientation of the PTMs identified and their effect on nucleosome stability and DNA binding potential. From our nucleosome model, it is evident that substitution of specific amino acid residues in TH2B results in both differential histone-DNA and histone-histone contacts. Furthermore, we have also observed that acetylation on the N-terminal tail of TH2B weakens the interactions with the DNA. These results provide direct evidence that, similar to somatic H2B, the testis specific histone TH2B also undergoes multiple PTMs, suggesting the possibility of chromatin regulation by such covalent modifications in mammalian male germ cells.

  16. Chronic cat-allergen exposure induces a TH2 cell-dependent IgG4 response related to low-sensitization

    PubMed Central

    Renand, Amedee; Archila, Luis D.; McGinty, John; Wambre, Erik; Robinson, David; Hales, Belinda J.; Thomas, Wayne R.; Kwok, William W.

    2015-01-01

    Background In human subjects, allergen-tolerance has been observed after high dose allergen exposure or after completed allergen immunotherapy, which is related to the accumulation of anti-inflammatory IgG4. However, the specific T cell response that leads to the induction of IgG4 during chronic allergen exposure remains poorly understood. Objective To evaluate the relationship between cat allergen-specific T cell frequency, cat allergen-specific IgE and IgG4 titers and clinical status in cat allergic adults with and without cat ownership and the cellular mechanism by which IgG4 is produced. Methods Fel d 1, Fel d 4, Fel d 7 and Fel d 8- specific T cell responses were characterized by CD154 expression after antigen stimulation. Results In allergic subjects without cat ownership, the frequency of cat allergen (Fel d 1 and Fel d 4) specific TH2 cells (sTH2 cells) correlates with IgE level and is linked to asthma. Paradoxically, we observed that cat allergic subjects with chronic cat exposure maintain high frequency of sTH2 cells, which correlates with IgG4 level and low-sensitization. B cells from allergic, but not from non-allergic subjects, are able to produce IgG4 after cognate interactions with sTH2 clones, and Fel d 1 peptide or the Fel d 1 recombinant protein. Conclusion These experiments suggest that 1) allergen-experienced B cells with capacity to produce IgG4 are present in allergic subjects; and 2) cat-allergen exposure induces an IgG4 response in a TH2 cell-dependent manner. Thus, IgG4 accumulation could be mediated by chronic activation of the TH2 response, which in turn drives desensitization. PMID:26371841

  17. Down-regulation of E-cadherin in human bronchial epithelial cells leads to epidermal growth factor receptor-dependent Th2 cell-promoting activity.

    PubMed

    Heijink, Irene H; Kies, P Marcel; Kauffman, Henk F; Postma, Dirkje S; van Oosterhout, Antoon J M; Vellenga, Edo

    2007-06-15

    Airway epithelial cells are well-known producers of thymus- and activation-regulated chemokine (TARC), a Th2 cell-attracting chemokine that may play an important role in the development of allergic airway inflammation. However, the mechanism responsible for up-regulation of TARC in allergy is still unknown. In the asthmatic airways, loss of expression of the cell-cell contact molecule E-cadherin and reduced epithelial barrier function has been observed, which may be the result of an inadequate repair response. Because E-cadherin also suppressed multiple signaling pathways, we studied whether disruption of E-cadherin-mediated cell contact may contribute to increased proallergic activity of epithelial cells, e.g., production of the chemokine TARC. We down-regulated E-cadherin in bronchial epithelial cells by small interference RNA and studied effects on electrical resistance, signaling pathways, and TARC expression (by electric cell-substrate impedance sensing, immunodetection, immunofluorescent staining, and real-time PCR). Small interference RNA silencing of E-cadherin resulted in loss of E-cadherin-mediated junctions, enhanced phosphorylation of epidermal growth factor receptor (EGFR), and the downstream targets MEK/ERK-1/2 and p38 MAPK, finally resulting in up-regulation of TARC as well as thymic stromal lymphopoietin expression. The use of specific inhibitors revealed that the effect on TARC is mediated by EGFR-dependent activation of the MAPK pathways. In contrast to TARC, expression of the Th1/Treg cell-attracting chemokine RANTES was unaffected by E-cadherin down-regulation. In summary, we show that loss of E-cadherin-mediated epithelial cell-cell contact by damaging stimuli, e.g., allergens, may result in reduced suppression of EGFR-dependent signaling pathways and subsequent induction of Th2 cell-attracting molecule TARC. Thus, disruption of intercellular epithelial contacts may specifically promote Th2 cell recruitment in allergic asthma.

  18. Increased expression of surface CD44 in hypoxia-DCs skews helper T cells toward a Th2 polarization

    PubMed Central

    Yang, Meixiang; Liu, Yanguo; Ren, Guangwen; Shao, Qianqian; Gao, Wenjuan; Sun, Jintang; Wang, Huayang; Ji, Chunyan; Li, Xingang; Zhang, Yun; Qu, Xun

    2015-01-01

    A low partial oxygen pressure (hypoxia) occurs in many pathological environments, such as solid tumors and inflammatory lesions. Understanding the cellular response to hypoxic stress has broad implications for human diseases. As we previously reported, hypoxia significantly altered dendritic cells (DCs) to a DC2 phenotype and promoted a Th2 polarization of naïve T cells with increased IL-4 production. However, the underlying mechanisms still remain largely unknown. In this study, we found the over-expression of surface CD44 in DCs was involved in this process via ligand binding. Further investigation showed hypoxia could reduce the surface expression of membrane type 1 metalloprotease (MT1-MMP) via down-regulating the kinesin-like protein KIF2A, which subsequently alleviated the shedding of CD44 from DCs. Moreover, KIF2A expression was found negatively regulated by HIF-1α in hypoxic microenvironment. These results suggest a previously uncharacterized mechanism by which hypoxia regulates the function of DCs via KIF2A/MT1-MMP/CD44 axis, providing critical information to understand the immune response under hypoxia. PMID:26323509

  19. Correlation between the kinetics of Th1, Th2 cells and pathology in a murine model of experimental pulmonary tuberculosis.

    PubMed Central

    Hernández-Pando, R; Orozcoe, H; Sampieri, A; Pavón, L; Velasquillo, C; Larriva-Sahd, J; Alcocer, J M; Madrid, M V

    1996-01-01

    T-helper 1 (Th1) Th2 kinetics were studied by immunohistochemistry and molecular biology techniques (reverse transcriptase polymerase chain reaction. RT PCR, Southern-blot) during the course of pulmonary tuberculosis induced in BALB/c mice by the intratracheal instillation of the live and virulent strain H-37Rv. The histopathological study clearly showed two phases of the disease. The first one was an acute phase which was characterized by inflammatory infiltrate in the alveolar capillary interstitium, blood vessel and bronchial wall with formation of granulomas. In this acute phase which lasted from 1 to 28 days, a clear predominance of Th1 cells was observed, manifested by a high percentage of interleukin-2 (IL-2) positive cells in the inflammatory infiltrate and granulomas demonstrated by immunohistology, as well as a gradual increment of interferon-gamma (INF-gamma) m-RNA. This was followed by a chronic or advanced phase characterized by pneumonia, focal necrosis and fibrosis, with a Th0 balance due to an equivalent proportion of IL-2 and IL-4 positive cells in the lung lesions, that coincided with the highest level of INF-gamma and IL-4 mRNA. The cytofluorometric analysis of bronchial lavage cells, showed a predominance of CD4 T cells during the acute phase and CD8 T lymphocytes in the chronic phase, gamma-delta T lymphocytes showed two peaks, at the beginning (3 days) and at the end (4 months) of the infection. These results suggest that T-lymphocyte subset kinetics and the pattern of cytokines produced in the lung during tuberculosis infection changed over time and correlate with the type and magnitude of tissue injury. Images Figure 1 Figure 3 Figure 5 PMID:8911136

  20. Resting Respiratory Tract Dendritic Cells Preferentially Stimulate T Helper Cell Type 2 (Th2) Responses and Require Obligatory Cytokine Signals for Induction of  Th1 Immunity

    PubMed Central

    Stumbles, Philip A.; Thomas, Jennifer A.; Pimm, Carolyn L.; Lee, Peter T.; Venaille, Thierry J.; Proksch, Stephen; Holt, Patrick G.

    1998-01-01

    Consistent with their role in host defense, mature dendritic cells (DCs) from central lymphoid organs preferentially prime for T helper cell type 1 (Th1)-polarized immunity. However, the “default” T helper response at mucosal surfaces demonstrates Th2 polarity, which is reflected in the cytokine profiles of activated T cells from mucosal lymph nodes. This study on rat respiratory tract DCs (RTDCs) provides an explanation for this paradox. We demonstrate that freshly isolated RTDCs are functionally immature as defined in vitro, being surface major histocompatibility complex (MHC) II lo, endocytosishi, and mixed lymphocyte reactionlo, and these cells produce mRNA encoding interleukin (IL)-10. After ovalbumin (OVA)-pulsing and adoptive transfer, freshly isolated RTDCs preferentially stimulated Th2-dependent OVA-specific immunoglobulin (Ig)G1 responses, and antigen-stimulated splenocytes from recipient animals produced IL-4 in vitro. However, preculture with granulocyte/macrophage colony stimulating factor increased their in vivo IgG priming capacity by 2–3 logs, inducing production of both Th1- and Th2-dependent IgG subclasses and high levels of IFN-γ by antigen-stimulated splenocytes. Associated phenotypic changes included upregulation of surface MHC II and B7 expression and IL-12 p35 mRNA, and downregulation of endocytosis, MHC II processing– associated genes, and IL-10 mRNA expression. Full expression of IL-12 p40 required additional signals, such as tumor necrosis factor α or CD40 ligand. These results suggest that the observed Th2 polarity of the resting mucosal immune system may be an inherent property of the resident DC population, and furthermore that mobilization of Th1 immunity relies absolutely on the provision of appropriate microenvironmental costimuli. PMID:9841916

  1. Coincident diabetes mellitus modulates Th1-, Th2-, and Th17-cell responses in latent tuberculosis in an IL-10- and TGF-β-dependent manner.

    PubMed

    Kumar, Nathella Pavan; Moideen, Kadar; George, Parakkal Jovvian; Dolla, Chandrakumar; Kumaran, Paul; Babu, Subash

    2016-02-01

    Type 2 diabetes mellitus (DM) is a risk factor for the development of active tuberculosis (TB), although its role in the TB-induced responses in latent TB (LTB) is not well understood. Since Th1, Th2, and Th17 responses are important in immunity to LTB, we postulated that coincident DM could alter the function of these CD4(+) T-cell subsets. To this end, we examined mycobacteria-induced immune responses in the whole blood of individuals with LTB-DM and compared them with responses of individuals without DM (LTB-NDM). T-cell responses from LTB-DM are characterized by diminished frequencies of mono- and dual-functional CD4(+) Th1, Th2, and Th17 cells at baseline and following stimulation with mycobacterial antigens-purified protein derivative, early secreted antigen-6, and culture filtrate protein-10. This modulation was at least partially dependent on IL-10 and TGF-β, since neutralization of either cytokine resulted in significantly increased frequencies of Th1 and Th2 cells but not Th17 cells in LTB-DM but not LTB individuals. LTB-DM is therefore characterized by diminished frequencies of Th1, Th2, and Th17 cells, indicating that DM alters the immune response in latent TB leading to a suboptimal induction of protective CD4(+) T-cell responses, thereby providing a potential mechanism for increased susceptibility to active disease.

  2. Suppression of allergic reactions by dehulled adlay in association with the balance of TH1/TH2 cell responses.

    PubMed

    Hsu, Hsin-Yi; Lin, Bi-Fong; Lin, Jin-Yuarn; Kuo, Ching-Chuan; Chiang, Wenchang

    2003-06-18

    Dehulled adlay is known as a natural Chinese medicine having antiallergic activity, although its mechanism remains unclear. This study examined the effects of dehulled adlay on antigen-specific antibody and cytokine production. Mice were immunized three times with ovalbumin (OVA) in alum adjuvant. It was found that oral administration of dehulled adlay in mice suppressed the production of IgE against OVA antigen. Serum anti-OVA IgG(2a) antibody levels were significantly increased in mice after oral administration of dehulled adlay. Furthermore, the production of IL-2 by OVA-stimulated splenocytes was augmented in dehulled adlay-fed mice. Although dehulled adlay had no effect on the serum anti-OVA IgG(1) antibody levels, it had a great capacity to reduce IL-5 secretion by means of OVA-stimulated splenocytes. Hydrothermal processes, including steaming and extrusion cooking, did not change the capacity of dehulled adlay to suppress IgE production. Three fractions of dehulled alday, including methanolic extract, warm water extract, and residue, were obtained. The methanolic extract exhibited the greatest capacity to reduce anti-OVA IgE production. These results suggest that dehulled adlay has a modulating ability to shift the balance from Th2 to Th1 dominance in the T cell mediated immune system and may be beneficial for the treatment of allergic disorders.

  3. SH2 domain–containing adaptor protein B expressed in dendritic cells is involved in T-cell homeostasis by regulating dendritic cell–mediated Th2 immunity

    PubMed Central

    2017-01-01

    Purpose The Src homology 2 domain–containing adaptor protein B (SHB) is widely expressed in immune cells and acts as an important regulator for hematopoietic cell function. SHB silencing induces Th2 immunity in mice. SHB is also involved in T-cell homeostasis in vivo. However, SHB has not yet been studied and addressed in association with dendritic cells (DCs). Materials and Methods The effects of SHB expression on the immunogenicity of DCs were assessed by Shb gene silencing in mouse bone marrow–derived DCs (BMDCs). After silencing, surface phenotype, cytokine expression profile, and T-cell stimulation capacity of BMDCs were examined. We investigated the signaling pathways involved in SHB expression during BMDC development. We also examined the immunogenicity of SHB-knockdown (SHBKD) BMDCs in a mouse atopic dermatitis model. Results SHB was steadily expressed in mouse splenic DCs and in in vitro–generated BMDCs in both immature and mature stages. SHB expression was contingent on activation of the mitogen- activated protein kinase/Foxa2 signaling pathway during DC development. SHBKD increased the expression of MHC class II and costimulatory molecules without affecting the cytokine expression of BMDCs. When co-cultured with T cells, SHBKD in BMDCs significantly induced CD4+ T-cell proliferation and the expression of Th2 cytokines, while the regulatory T cell (Treg) population was downregulated. In mouse atopic dermatitis model, mice inoculated with SHBKD DCs developed more severe symptoms of atopic dermatitis compared with mice injected with control DCs. Conclusion SHB expression in DCs plays an important role in T-cell homeostasis in vivo by regulating DC-mediated Th2 polarization. PMID:28168174

  4. Elevated Levels of Cytokines Associated with Th2 and Th17 Cells in Vitreous Fluid of Proliferative Diabetic Retinopathy Patients.

    PubMed

    Takeuchi, Masaru; Sato, Tomohito; Tanaka, Atsushi; Muraoka, Tadashi; Taguchi, Manzo; Sakurai, Yutaka; Karasawa, Yoko; Ito, Masataka

    2015-01-01

    Macrophages are involved in low-grade inflammation in diabetes, and play pathogenic roles in proliferative diabetic retinopathy (PDR) by producing proinflammatory cytokines. T cells as well as other cells are also activated by proinflammatory cytokines, and infiltration into the vitreous of patients with PDR has been shown. In this study, we measured helper T (Th) cell-related cytokines in the vitreous of PDR patients to define the characteristics of Th-mediated immune responses associated with PDR. The study group consisted of 25 type 2 diabetic patients (25 eyes) with PDR. The control group consisted of 27 patients with epiretinal membrane (ERM), 26 patients with idiopathic macular hole (MH), and 26 patients with uveitis associated with sarcoidosis. Vitreous fluid was obtained at the beginning of vitrectomy, and centrifuging for cellular removals was not performed. Serum was also collected from PDR patients. IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, soluble sCD40L, and TNFα in the vitreous and serum samples were measured. Both percent detectable and levels of IL-4, IL-6, IL-17A, IL-21, IL-22, and TNFα in the vitreous were significantly higher than those in the serum in PDR patients. Vitreous levels of these cytokines and IL-31 were significantly higher in PDR than in ERM or MH patients. Vitreous levels of IL-4, IL-17A, IL-22, IL-31, and TNFα in PDR patients were also significantly higher than those of sarcoidosis patients. In PDR patients, vitreous IL-17A level correlated significantly with vitreous levels of IL-22 and IL-31, and especially with IL-4 and TNFα. Although it is unclear whether these cytokines play facilitative roles or inhibitory roles for the progression of PDR, the present study indicated that Th2- and Th17-related immune responses are involved in the pathogenesis of PDR.

  5. Upregulation of Tim-3 on CD4(+) T cells is associated with Th1/Th2 imbalance in patients with allergic asthma.

    PubMed

    Tang, Fei; Wang, Fukun; An, Liyun; Wang, Xianling

    2015-01-01

    T cell Ig and mucin domain-containing molecule-3 (Tim-3) is a negative regulator preferentially expressed on Th1 cells. Allergic asthma is a clinical syndrome well characterized by Th1/Th2 imbalance. To investigate the role of Tim-3 in the pathogenesis of asthma and its relationship with Th1/Th2 imbalance, a total of 40 patients with allergic asthma and 40 healthy controls were enrolled. Expression of Tim-3 and Th1/Th2 imbalance as well as the relationship between them was analyzed by flow cytometry and real-time PCR. Peripheral blood mononuclear cells (PBMCs) were cultured in vitro and anti-Tim-3 was used to block Tim-3 signaling; Th1/Th2 cytokines in the culture supernatant were detected by enzyme linked immunosorbent assay (ELISA). CD4(+) T cells and B cells were sorted and co-cultured in vitro, and anti-Tim-3 was used to block Tim-3 signaling; Total IgG/IgE in the culture supernatant was detected by ELISA. The mRNA level of T-bet and IFN-γ were significantly decreased in allergic asthma patients, while GATA-3 and IL-4 were significantly increased. Expression of Tim-3 on CD4(+) T cells was much higher in allergic asthma patients and it was negatively correlated with T-bet/GATA-3 ratio or IFN-γ/IL-4 ratio. Blocking of Tim-3 significantly increased Th1 cytokines (TNF-α and IFN-γ) and decreased Th2 cytokines (IL-4, IL-5, IL-13) in the culture supernatant of PBMCs. Blocking of Tim-3 dramatically reduced the production of IgG and IgE in the co-culture supernatant of CD4(+) T cells and B cells. In conclusion, Tim-3 was up-regulated in allergic asthma patients and related with the Th1/Th2 imbalance. Blocking of Tim-3 may be of therapeutic benefit by enhancing the Th1 cytokines response, down-regulating the Th2 cytokines response, and reducing IgG/IgE production.

  6. Sirtuin 1 promotes Th2 responses and airway allergy by repressing peroxisome proliferator-activated receptor-γ activity in dendritic cells.

    PubMed

    Legutko, Agnieszka; Marichal, Thomas; Fiévez, Laurence; Bedoret, Denis; Mayer, Alice; de Vries, Hilda; Klotz, Luisa; Drion, Pierre-Vincent; Heirman, Carlo; Cataldo, Didier; Louis, Renaud; Thielemans, Kris; Andris, Fabienne; Leo, Oberdan; Lekeux, Pierre; Desmet, Christophe J; Bureau, Fabrice

    2011-11-01

    Sirtuins are a unique class of NAD(+)-dependent deacetylases that regulate diverse biological functions such as aging, metabolism, and stress resistance. Recently, it has been shown that sirtuins may have anti-inflammatory activities by inhibiting proinflammatory transcription factors such as NF-κB. In contrast, we report in this study that pharmacological inhibition of sirtuins dampens adaptive Th2 responses and subsequent allergic inflammation by interfering with lung dendritic cell (DC) function in a mouse model of airway allergy. Using genetic engineering, we demonstrate that sirtuin 1 represses the activity of the nuclear receptor peroxisome proliferator-activated receptor-γ in DCs, thereby favoring their maturation toward a pro-Th2 phenotype. This study reveals a previously unappreciated function of sirtuin 1 in the regulation of DC function and Th2 responses, thus shedding new light on our current knowledge on the regulation of inflammatory processes by sirtuins.

  7. CD4+ Th17 Cells Discriminate Clinical Types and Constitute a Third Subset of Non Th1, Non Th2 T Cells in Human Leprosy

    PubMed Central

    Saini, Chaman; Ramesh, V.; Nath, Indira

    2013-01-01

    Background Patients with localized tuberculoid and generalized lepromatous leprosy show respectively Th1 and Th2 cytokine profile. Additionally, other patients in both types of leprosy also show a non discriminating Th0 cytokine profile with both interferon-γ and IL-4. The present study investigated the role of Th17 cells which appear to be a distinct subtype of Th subtypes in 19 tuberculoid and 18 lepromatous leprosy patients. Five healthy subjects with long term exposure to infection and 4 skin biopsies from healthy subjects undergoing cosmetic surgery were used as controls. Methodology/Principle Findings An array of Th17 related primers for cytokines, chemokines and transcription factors was used in real time reverse transcribed PCR to evaluate gene expression, ELISA for cytokine secretion in the supernatants of antigen stimulated PBMC cultures and flow cytometry for establishing the phenotype of the IL-17, IL-21 producing cells. Conclusions/Significance IL-17 isoforms showed significantly higher expression and release in supernatants of antigen stimulated PBMC cultures and dermal lesions of healthy contacts and tuberculoid leprosy as compared to lepromatous leprosy (p<0.003). This was further confirmed by Th17 associated transcription factor RORC, cytokines IL-21, IL-22, and IL-23, chemokines MMP13, CCL20, CCL22. Of interest was the association of IL-23R and not IL-6R with IL-17+ cells. The Th17 cells were CD4+ CCR6+ confirming their effector cell lineage. Polarized Th1 cytokines were seen in 3/7 tuberculoid and Th2 cytokines in 5/10 lepromatous leprosy patients. Of importance was the higher association of Th17 pathway factors with the non-polarized Th0 types as compared to the polarized Th1 and Th2 (p<0.01). Our study draws attention to a third type of effector Th cell that may play a role in leprosy. PMID:23936569

  8. SB-273005, an antagonist of αvβ3 integrin, reduces the production of Th2 cells and cytokine IL-10 in pregnant mice.

    PubMed

    Wang, Shaojuan; Yang, Jing; Wang, Chongyang; Yang, Qing; Zhou, Xiaoli

    2014-06-01

    Pregnancy is associated with complex immunoreactions. In the present study, the effect of SB-273005, an antagonist of αvβ3 integrin, on the alterations of T helper (Th) cells and their derived cytokines that occur during pregnancy was investigated in mice. Five non-pregnant mice were used as a negative control. Mice were impregnated by co-housing females and males at a ratio of 2:1 overnight and pregnancy was confirmed by the appearance of vaginal plugs the following morning. Day 1 (D1) pregnant mice were randomly divided into two groups (n=20) and were administered either dimethylsulfoxide (mock treatment) or SB-273005 (3 mg/kg) by gavage at D3, D4 and D5. At D8, the levels of Th1 and Th2 cells and interleukin (IL)-2 and IL-10 in the spleen and peripheral blood were determined using flow cytometry and enzyme-linked immunosorbent assay. Pregnancy significantly increased the ratio of Th2:Th1 cells in the spleen compared with that in non-pregnant mice (P<0.01). However, this increase was significantly reduced by SB-273005 (P<0.001). Furthermore, whilst pregnancy decreased Th1 cell-produced IL-2 levels and increased Th2 cell-derived IL-10 levels, SB-273005 reversed both processes (P<0.05 for IL-2; P<0.01 for IL-10). The results from the present study demonstrated that pregnancy induces changes in the spleen, including a reduction of IL-2 and an increase in IL-10 production by Th1 and Th2 cells, respectively, as well as an upregulation of the Th2:Th1 ratio in the spleen. These immunological changes are reversed by SB-273005, indicating an important role for αvβ3 integrin in mediating these immunological alterations.

  9. Effect of vitamin D supplementation during pregnancy on the Th1/Th2 cell balance of rat offspring.

    PubMed

    Chen, Wen-Jia; Hou, Xue-Jing; Yang, Shu-Fen; Yin, Xin-Hua; Ren, Lihong

    2014-05-01

    Vitamin D has important functions in the immune system, and it may suppress the proliferation of T helper (Th) cells and modulate their cytokine production. In this study, we aimed to investigate the effects of maternal supplementation with different doses of vitamin D on the allergy status of the offspring. We gave pregnant female rats a low dose (48000IU/kg, equal to 800IU/d in human) and a high dose (240000IU/kg,equal to 4000IU/d in human) of vitamin D3 intramuscular injection on gestation day (GD)17, and we used an enzyme-linked immunosorbent assay (ELISA) to determine the levels of immune responsive cytokines including IL-4, IgE, and interferon gamma (IFN-gamma) in the offspring. On postnatal day (PND) 21, plasma IL-4 levels were elevated by 10.43% (p < 0.01) in the offspring from the high dose vitamin D3 group compared with the control group. And offspring plasma IL-4 levels in the low dose group decreased by 7.27% (p < 0.05) compared with the control dose group. We found that the offspring of mothers given a low dose of vitamin D3 had a 6.17% (p < 0.01) decrease in their plasma IgE levels compared to control animals, but the high dose of vitamin D3 showed no effect. The serum 25(OH)D3 levels were negatively correlated with the IL-4 (r = -0.561, p < 0.01) and IgE (r = -0.421, p < 0.05) levels of the offspring from the low dose group. In the lung tissues of the offspring of the high dose group, we observed thickening of the alveolar septa and more inflammatory cells compared with the control group and low dose group. Thickened alveolar septa were also found in the lung tissues of the offspring from the control group. We conclude that high dose vitamin D3 maternal supplementation during pregnancy induced an imbalance of Th1 and Th2 cells in their offspring resulting allergic and inflammatory response.

  10. Cyclosporine A enhances Th2 bias at the maternal-fetal interface in early human pregnancy with aid of the interaction between maternal and fetal cells.

    PubMed

    Piao, Hai-Lan; Wang, Song-Cun; Tao, Yu; Zhu, Rui; Sun, Chan; Fu, Qiang; Du, Mei-Rong; Li, Da-Jin

    2012-01-01

    Our previous study has demonstrated that cyclosporine A (CsA) administration in vivo induces Th2 bias at the maternal-fetal interface, leading to improved murine pregnancy outcomes. Here, we investigated how CsA treatment in vitro induced Th2 bias at the human maternal-fetal interface in early pregnancy. The cell co-culture in vitro in different combination of component cells at the maternal-fetal interface was established to investigate the regulation of CsA on cytokine production from the interaction of these cells. It was found that interferon (IFN)-γ was produced only by decidual immune cells (DICs), and not by trophoblasts or decidual stromal cells (DSCs); all these cells secreted interleukin (IL)-4, IL-10, and tumor necrosis factor (TNF)-α. Treatment with CsA completely blocked IFN-γ production in DICs and inhibited TNF-α production in all examined cells. CsA increased IL-10 and IL-4 production in trophoblasts co-cultured with DSCs and DICs although CsA treatment did not affect IL-10 or IL-4 production in any of the cells when cultured alone. These results suggest that CsA promotes Th2 bias at the maternal-fetal interface by increasing Th2-type cytokine production in trophoblasts with the aid of DSCs and DICs, while inhibiting Th1-type cytokine production in DICs and TNF-α production in all investigated cells. Our study might be useful in clinical therapeutics for spontaneous pregnancy wastage and other pregnancy complications.

  11. Th2 and Tc2 cells in the regulation of GVHD, GVL, and graft rejection: considerations for the allogeneic transplantation therapy of leukemia and lymphoma.

    PubMed

    Fowler, D H; Gress, R E

    2000-07-01

    Allogeneic stem cell transplantation (SCT) represents a curative treatment option for patients with leukemia and lymphoma. T lymphocytes contained in the allograft mediate a graft-versus-leukemia (GVL) effect and prevent graft rejection; however, T cells also initiate graft-versus-host disease (GVHD). Identification of T cell populations which mediate a GVL effect and prevent rejection with reduced GVHD will likely improve transplantation outcome. T cells exist in four functionally-defined populations, the CD4+, Th1/Th2 and CD8+, Tc1/Tc2 subsets. Th1-type CD4 cells primarily secrete type I cytokines (IL-2 and IFN-gamma), whereas Th2 cells secrete type II cytokines (IL-4, IL-5, and IL-10). Similarly, the CD8+ Tc1 and Tc2 cells differentially secrete the type I and type II cytokines, respectively. In addition to cytokine secretion, Tc1 and Tc2 populations mediate cytolytic effects, with Tc1 cells utilizing both perforin- and fas-based killing pathways, whereas Tc2 cells primarily utilize perforin-mediated cytolysis. In murine transplantation models of graft rejection, GVHD, and GVL effects, we have evaluated such functional T cell subsets for their ability to differentially mediate and regulate transplantation responses. These studies demonstrate that donor Th2 cells do not initiate acute GVHD, and can regulate the GVHD mediated by unmanipulated donor T cells without impairing alloengraftment. Additional experiments have shown that allospecific donor Tc2 cells result in reduced GVHD, and mediate a significant GVL effect. Thirdly, we have demonstrated that non-host reactive Tc2 cells with veto-like activity can potently abrogate marrow rejection independent of GVHD. Together, these results demonstrate that functionally-defined donor Th2 and Tc2 populations play an important role in the regulation of GVHD, the prevention of graft rejection, and the mediation of GVL effects, and suggest that utilization of Th2 and Tc2 cells in clinical allogeneic SCT may have potential

  12. TH1/TH2 cytokines in the central nervous system.

    PubMed

    Sredni-Kenigsbuch, Dvora

    2002-06-01

    For the past 20 years it has become increasingly evident that cytokines play an important role in both the normal development of the brain, acting as neurotrophic factors, and in brain injuries. Although cytokines and their receptors are synthesized and expressed in the brain (normally at low levels), increased cytokine production levels are now associated with various neurological disorders. T lymphocytes are the cells responsible for coordinating the immune response and a major source of cytokines. Different cytokines induce different subsets of T cells or have different effects on proliferation within a particular subset. Recent studies suggest that the immune response is in fact regulated by the balance between Th1 and Th2 cytokines. These two pathways are often mutually exclusive, the one resulting in protection and the other in progression of disease. Various studies describe the function and production of proinflammatory cytokines in the central nervous system (CNS) and their role in health and disease. Inflammation is upregulated following activation of Th1 cells, whereas Th2 cells may play a significant role in downregulating Th1 proinflammatory responses in those instances in which there is overproduction of Th2 cytokines. Although both Th1 and Th2 cytokines may influence CNS functioning, most studies have so far dealt with proinflammatory cytokines, probably because they directly affect CNS cells and are thought to be implicated in CNS pathology. It is of interest that endogenous glucocorticoids also control Th1-Th2 balance, favoring Th2 cell development. This review presents the evidence that cytokines have important functions in the CNS, both during development and as a part of brain pathology. In particular, the author highlighted recent work that supports a major role for the so-called inflammatory cytokines, Th1, and the anti-inflammatory Th2 cytokines.

  13. Study of Th1/Th2 balance in peripheral blood mononuclear cells of patients with alopecia areata.

    PubMed

    Sadeghi, Soha; Sanati, Mohammad Hossein; Taghizadeh, Morteza; Mansouri, Parvine; Jadali, Zohreh

    2015-09-01

    Alopecia areata represents an autoimmune pathological process driven primarily by cellular aberrations contained within the immune system, which activates various humoral and cellular elements of the immune response. The aim of this study was to determine the mRNA expression levels of T-bet and GATA-3 as potential inducers of T helper (Th)1 and Th2 differentiation, respectively, as well as Th1(IFN-γ) and Th2(IL-4) cytokine mRNA expression in patients with alopecia areata. Using real-time reverse transcriptase PCR (RT-PCR), the relative amounts of T-bet, GATA-3, IFN-γ, and IL-4 mRNA transcripts were determined in PBMCs from 20 Iranian patients with alopecia areata and compared with those of 20 healthy control subjects. In comparison with the normal group, T-bet and IFN-γ mRNA expression levels were significantly up-regulated in the alopecia areata patients, while GATA-3 and IL-4 mRNA expression levels were down-regulated. Notably, positive correlation (P < 0.05) was found between IFN-γ and T-bet levels in patients and controls. In addition, significant positive correlations existed between GATA-3 and IL-4 (P < 0.05). These results indicate that a Th1/Th2 imbalance exists in alopecia areata, and it may be implicated in the pathogenesis of disease.

  14. Transcriptome signature for dampened Th2 dominance in acellular pertussis vaccine-induced CD4+ T cell responses through TLR4 ligation

    PubMed Central

    Brummelman, Jolanda; Raeven, René H. M.; Helm, Kina; Pennings, Jeroen L. A.; Metz, Bernard; van Eden, Willem; van Els, Cécile A. C. M.; Han, Wanda G. H.

    2016-01-01

    Current acellular pertussis (aP) vaccines promote a T helper 2 (Th2)-dominated response, while Th1/Th17 cells are protective. As our previous study showed, after adding a non-toxic TLR4 ligand, LpxL1, to the aP vaccine in mice, the Bordetella pertussis-specific Th2 response is decreased and Th1/Th17 responses are increased as measured at the cytokine protein level. However, how this shift in Th response by LpxL1 addition is regulated at the gene expression level remains unclear. Transcriptomics analysis was performed on purified CD4+ T cells of control and vaccinated mice after in vitro restimulation with aP vaccine antigens. Multiple key factors in Th differentiation, including transcription factors, cytokines, and receptors, were identified within the differentially expressed genes. Upregulation of Th2- and downregulation of follicular helper T cell-associated genes were found in the CD4+ T cells of both aP- and aP+LpxL1-vaccinated mice. Genes exclusively upregulated in CD4+ T cells of aP+LpxL1-vaccinated mice included Th1 and Th17 signature cytokine genes Ifng and Il17a respectively. Overall, our study indicates that after addition of LpxL1 to the aP vaccine the Th2 component is not downregulated at the gene expression level. Rather an increase in expression of Th1- and Th17-associated genes caused the shift in Th subset outcome. PMID:27118638

  15. Expression of Th1, Th2, lymphocyte trafficking and activation markers on CD4+ T-cells of Hymenoptera allergic subjects and after venom immunotherapy.

    PubMed

    Cabrera, Carmen M; Urra, José M; Alfaya, Teresa; Roca, Federico De La; Feo-Brito, Francisco

    2014-11-01

    Systemic reactions to Hymenoptera stings can be fatal and represent a reduction in the quality of life. The immune mechanisms involved in venom allergic subjects are barely known. Nevertheless, a shift towards a Th1-type response with an increase in IFNγ levels has been observed after venom immunotherapy (VIT). There is currently no information available about the expression of markers on CD4+ T-cells or their involvement in venom allergy, nor following VIT. For this, we have studied the expression of Th1 and Th2-cell markers, homing receptors and activation markers on CD4+ T-cells of subjects who presented systemic allergic reactions, mainly to Polistes dominulus, and after receiving a 4-month conventional VIT protocol. The markers studied were: CD26 (Th1), CD30 (Th2), CXCR4, CXCR3 (Th1), CCR4 (Th2), CD154 (CD40L), CD152 (CTLA-A), and ICOS. We also determined the IL-4 (Th2) and IFNγ (Th1) intracellular cytokine levels in T-cells and carried out a basophil activation test (BAT). Comparing venom allergic subjects with non-allergic healthy controls, we have found up-regulation of CD26, CXCR4, CXCR3, CD154 and ICOS. Conversely, a down-regulation of CD30, CD154 and CD152 occurred upon immune intervention, whereas the remaining markers were not affected. Equally, VIT has been shown to be effective, as evidenced by the decrease of basophil degranulation and increase of IFNγ levels in T-cells after the fourth month of treatment. These new findings highlight the possible application of these surface molecules as markers to distinguish between symptomatic and asymptomatic subjects sensitized to Hymenoptera venom, as well as revealing information about the immune changes associated with VIT.

  16. Ferulic Acid Induces Th1 Responses by Modulating the Function of Dendritic Cells and Ameliorates Th2-Mediated Allergic Airway Inflammation in Mice

    PubMed Central

    Lee, Chen-Chen; Wang, Ching-Chiung; Huang, Huei-Mei; Lin, Chu-Lun; Leu, Sy-Jye; Lee, Yueh-Lun

    2015-01-01

    This study investigated the immunomodulatory effects of ferulic acid (FA) on antigen-presenting dendritic cells (DCs) in vitro and its antiallergic effects against ovalbumin- (OVA-) induced Th2-mediated allergic asthma in mice. The activation of FA-treated bone marrow-derived DCs by lipopolysaccharide (LPS) stimulation induced a high level of interleukin- (IL-) 12 but reduced the expression levels of the proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor- (TNF-) α. Compared to control-treated DCs, FA significantly enhanced the expressions of Notch ligand Delta-like 4 (Dll4), MHC class II, and CD40 molecules by these DCs. Furthermore, these FA-treated DCs enhanced T-cell proliferation and Th1 cell polarization. In animal experiments, oral administration of FA reduced the levels of OVA-specific immunoglobulin E (IgE) and IgG1 and enhanced IgG2a antibody production in serum. It also ameliorated airway hyperresponsiveness and attenuated eosinophilic pulmonary infiltration in dose-dependent manners. In addition, FA treatment inhibited the production of eotaxin, Th2 cytokines (IL-4, IL-5, and IL-13), and proinflammatory cytokines but promoted the Th1 cytokine interferon- (IFN-) γ production in bronchoalveolar lavage fluid (BALF) and the culture supernatant of spleen cells. These findings suggest that FA exhibits an antiallergic effect via restoring Th1/Th2 imbalance by modulating DCs function in an asthmatic mouse model. PMID:26495021

  17. T Cell Polarization toward TH2/TFH2 and TH17/TFH17 in Patients with IgG4-Related Disease

    PubMed Central

    Grados, Aurélie; Ebbo, Mikael; Piperoglou, Christelle; Groh, Matthieu; Regent, Alexis; Samson, Maxime; Terrier, Benjamin; Loundou, Anderson; Morel, Nathalie; Audia, Sylvain; Maurier, François; Graveleau, Julie; Hamidou, Mohamed; Forestier, Amandine; Palat, Sylvain; Bernit, Emmanuelle; Bonotte, Bernard; Farnarier, Catherine; Harlé, Jean-Robert; Costedoat-Chalumeau, Nathalie; Vély, Frédéric; Schleinitz, Nicolas

    2017-01-01

    IgG4-related disease (IgG4-RD) is a fibro-inflammatory disorder involving virtually every organ with a risk of organ dysfunction. Despite recent studies regarding B cell and T cell compartments, the disease’s pathophysiology remains poorly understood. We examined and characterized subsets of circulating lymphocytes in untreated patients with active IgG4-RD. Twenty-eight consecutive patients with biopsy-proven IgG4-RD were included in a prospective, multicentric study. Lymphocytes’ subsets were analyzed by flow cytometry, with analysis of TH1/TH2/TH17, TFH cells, and cytokine release by peripheral blood mononuclear cells. Results were compared to healthy controls and to patients with primary Sjögren’s syndrome. Patients with IgG4-RD showed an increase of circulating T regulatory, TH2, TH17, and CD4+CXCR5+PD1+ TFH cell subsets. Accordingly, increased levels of IL-10 and IL-4 were measured in IgG-RD patients. TFH increase was characterized by the specific expansion of TFH2 (CCR6−CXCR3−), and to a lesser extent of TFH17 (CCR6+CXCR3−) cells. Interestingly, CD4+CXCR5+PD1+ TFH cells normalized under treatment. IgG4-RD is characterized by a shift of circulating T cells toward a TH2/TFH2 and TH17/TFH17 polarization. This immunological imbalance might be implicated in the disease’s pathophysiology. Treatment regimens targeting such T cells warrant further evaluation. PMID:28348556

  18. IL-25/IL-33–responsive TH2 cells characterize nasal polyps with a default TH17 signature in nasal mucosa

    PubMed Central

    Lam, Emily P.S.; Kariyawasam, Harsha H.; Rana, Batika M.J.; Durham, Stephen R.; McKenzie, Andrew N.J.; Powell, Nicholas; Orban, Nara; Lennartz-Walker, Melissa; Hopkins, Claire; Ying, Sun; Rimmer, Joanne; Lund, Valerie J.; Cousins, David J.; Till, Stephen J.

    2016-01-01

    Background Chronic rhinosinusitis with nasal polyposis (CRSwNP) in Western countries is characterized by eosinophilia, IgE production, and TH2 cytokine expression. Type 2 innate lymphoid cells from polyps produce IL-5 and IL-13 in response to IL-25 and IL-33, although the relevance of this axis to local mucosal T-cell responses is unknown. Objective We sought to investigate the role of the IL-25/IL-33 axis in local mucosal T-cell responses in patients with CRSwNP. Methods Polyp tissue and blood were obtained from patients undergoing nasal polypectomy. Control nasal biopsy specimens and blood were obtained from healthy volunteers. Tissue was cultured in a short-term explant model. T-cell surface phenotype/intracellular cytokines were assessed by means of flow cytometry. T-cell receptor variable β-chain analysis was performed with the immunoSEQ assay. Microarrays were performed for gene expression analysis. Results IL-25 receptor (IL-17RB)–expressing TH2 effector cells were identified in nasal polyp tissue but not the healthy nasal mucosa or periphery. IL-17RB+CD4+ polyp–derived TH2 cells coexpressed ST2 (IL-33 receptor) and responded to IL-25 and IL-33 with enhanced IL-5 and IL-13 production. Within IL-17RB+CD4+ T cells, several identical T-cell receptor variable β-chain complementarity-determining region 3 sequences were identified in different subjects, suggesting clonal expansion driven by a common antigen. Abundant IL-17–producing T cells were observed in both healthy nasal mucosal and polyp populations, with TH17-related genes the most overexpressed compared with peripheral blood T cells. Conclusion IL-25 and IL-33 can interact locally with IL-17RB+ST2+ polyp T cells to augment TH2 responses in patients with CRSwNP. A local TH17 response might be important in healthy nasal mucosal immune homeostasis. PMID:26684290

  19. Sublingual administration of Lactobacillus paracasei KW3110 inhibits Th2-dependent allergic responses via upregulation of PD-L2 on dendritic cells.

    PubMed

    Inamine, Ayako; Sakurai, Daijyu; Horiguchi, Shigetoshi; Yonekura, Syuji; Hanazawa, Toyoyuki; Hosokawa, Hiroyuki; Matuura-Suzuki, Asaka; Nakayama, Toshinori; Okamoto, Yoshitaka

    2012-05-01

    Lactic acid bacteria have potential in immunomodulation therapy, but their clinical efficacy and underlying mechanisms are unclear. We aimed to clarify the anti-allergic immune responses induced by intragastric and sublingual administration of heat-killed Lactobacillus paracasei KW3110 and Lactobacillus acidophilus L-92. The KW3110 strain (but not the L-92 strain) enhanced ovalbumin (OVA)-induced expression of CCR-7 and PD-L2 in murine dendritic cells (DCs), and strongly inhibited IL-5 and IL-13 production in vitro in co-cultures with Th2-skewed CD4(+) T cells from DO11.10 transgenic mice. Sublingual administration of low-dose KW3110 (but not L-92) to OVA-sensitized mice selectively suppressed serum IgE production and Th2 cytokine expression in cervical lymph nodes, and significantly improved symptoms after OVA provocation in vivo. KW3110 probably accelerates DC migration into the regional lymph nodes and inhibits Th2 cytokine production through enhanced CCR-7 and PD-L2 expression. Thus, sublingual KW3110 administration may be effective in reducing allergic inflammation.

  20. Compound A, a Dissociated Glucocorticoid Receptor Modulator, Inhibits T-bet (Th1) and Induces GATA-3 (Th2) Activity in Immune Cells

    PubMed Central

    Ferraz-de-Paula, Viviane; Palermo-Neto, Joao; Castro, Carla N.; Druker, Jimena; Holsboer, Florian; Perone, Marcelo J.; Gerlo, Sarah; De Bosscher, Karolien; Haegeman, Guy; Arzt, Eduardo

    2012-01-01

    Background Compound A (CpdA) is a dissociating non-steroidal glucocorticoid receptor (GR) ligand which has anti-inflammatory properties exerted by down-modulating proinflammatory gene expression. By favouring GR monomer formation, CpdA does not enhance glucocorticoid (GC) response element-driven gene expression, resulting in a reduced side effect profile as compared to GCs. Considering the importance of Th1/Th2 balance in the final outcome of immune and inflammatory responses, we analyzed how selective GR modulation differentially regulates the activity of T-bet and GATA-3, master drivers of Th1 and Th2 differentiation, respectively. Results Using Western analysis and reporter gene assays, we show in murine T cells that, similar to GCs, CpdA inhibits T-bet activity via a transrepressive mechanism. Different from GCs, CpdA induces GATA-3 activity by p38 MAPK-induction of GATA-3 phosphorylation and nuclear translocation. CpdA effects are reversed by the GR antagonist RU38486, proving the involvement of GR in these actions. ELISA assays demonstrate that modulation of T-bet and GATA-3 impacts on cytokine production shown by a decrease in IFN-γ and an increase in IL-5 production, respectively. Conclusions Taken together, through their effect favoring Th2 over Th1 responses, particular dissociated GR ligands, for which CpdA represents a paradigm, hold potential for the application in Th1-mediated immune disorders. PMID:22496903

  1. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for glial and neural-related molecules in central nervous system mixed glial cell cultures: neurotrophins, growth factors and structural proteins

    PubMed Central

    Lisak, Robert P; Benjamins, Joyce A; Bealmear, Beverly; Nedelkoska, Liljana; Yao, Bin; Land, Susan; Studzinski, Diane

    2007-01-01

    Background In multiple sclerosis, inflammatory cells are found in both active and chronic lesions, and it is increasingly clear that cytokines are involved directly and indirectly in both formation and inhibition of lesions. We propose that cytokine mixtures typical of Th1 or Th2 lymphocytes, or monocyte/macrophages each induce unique molecular changes in glial cells. Methods To examine changes in gene expression that might occur in glial cells exposed to the secreted products of immune cells, we have used gene array analysis to assess the early effects of different cytokine mixtures on mixed CNS glia in culture. We compared the effects of cytokines typical of Th1 and Th2 lymphocytes and monocyte/macrophages (M/M) on CNS glia after 6 hours of treatment. Results In this paper we focus on changes with potential relevance for neuroprotection and axon/glial interactions. Each mixture of cytokines induced a unique pattern of changes in genes for neurotrophins, growth and maturation factors and related receptors; most notably an alternatively spliced form of trkC was markedly downregulated by Th1 and M/M cytokines, while Th2 cytokines upregulated BDNF. Genes for molecules of potential importance in axon/glial interactions, including cell adhesion molecules, connexins, and some molecules traditionally associated with neurons showed significant changes, while no genes for myelin-associated genes were regulated at this early time point. Unexpectedly, changes occurred in several genes for proteins initially associated with retina, cancer or bone development, and not previously reported in glial cells. Conclusion Each of the three cytokine mixtures induced specific changes in gene expression that could be altered by pharmacologic strategies to promote protection of the central nervous system. PMID:18088439

  2. Quantitative Proteomics Analysis of the Nuclear Fraction of Human CD4+ Cells in the Early Phases of IL-4-induced Th2 Differentiation*

    PubMed Central

    Moulder, Robert; Lönnberg, Tapio; Elo, Laura L.; Filén, Jan-Jonas; Rainio, Eeva; Corthals, Garry; Oresic, Matej; Nyman, Tuula A.; Aittokallio, Tero; Lahesmaa, Riitta

    2010-01-01

    We used stable isotope labeling with 4-plex iTRAQ (isobaric tags for relative and absolute quantification) reagents and LC-MS/MS to investigate proteomic changes in the nucleus of activated human CD4+ cells during the early stages of Th2 cell differentiation. The effects of IL-4 stimulation upon activated naïve CD4+ cells were measured in the nuclear fractions from 6 and 24 h in three biological replicates, each using pooled cord blood samples derived from seven or more individuals. In these analyses, in the order of 800 proteins were detected with two or more peptides and quantified in three biological replicates. In addition to consistent differences observed with the nuclear localization/expression of established human Th2 and Th1 markers, there were changes that suggested the involvement of several proteins either only recently reported or otherwise not known in this context. These included SATB1 and among the novel changes detected and validated an IL-4-induced increase in the level of YB1. This unique data set from human cord blood CD4+ T cells details an extensive list of protein determinations that compares with and complements previous data determined from the Jurkat cell nucleus. PMID:20467038

  3. Stat6-Dependent Inhibition of Mincle Expression in Mouse and Human Antigen-Presenting Cells by the Th2 Cytokine IL-4

    PubMed Central

    Hupfer, Thomas; Schick, Judith; Jozefowski, Katrin; Voehringer, David; Ostrop, Jenny; Lang, Roland

    2016-01-01

    The C-type lectin receptors (CLRs) Mincle, Mcl, and Dectin-2 bind mycobacterial and fungal cell wall glycolipids and carbohydrates. Recently, we described that expression of these CLR is downregulated during differentiation of human monocytes to dendritic cells (DC) in the presence of GM-CSF and IL-4. Here, we demonstrate that the Th2 cytokine IL-4 specifically inhibits expression of Mincle, Mcl, and Dectin-2 in human antigen-presenting cells (APC). This inhibitory effect of IL-4 was observed across species, as murine macrophages and DC treated with IL-4 also downregulated these receptors. IL-4 blocked upregulation of Mincle and Mcl mRNA expression and cell surface protein by murine macrophages in response to the Mincle ligand Trehalose-6,6-dibehenate (TDB), whereas the TLR4 ligand LPS overcame inhibition by IL-4. Functionally, downregulation of Mincle expression by IL-4 was accompanied by reduced cytokine production upon stimulation with TDB. These inhibitory effects of IL-4 were dependent on the transcription factor Stat6. Together, our results show that the key Th2 cytokine IL-4 exerts a negative effect on the expression of Mincle and other Dectin-2 cluster CLR in mouse and human macrophages and DC, which may render these sentinel cells less vigilant for sensing mycobacterial and fungal ligands. PMID:27790218

  4. Interleukin-33 produced by M2 macrophages and other immune cells contributes to Th2 immune reaction of IgG4-related disease

    PubMed Central

    Furukawa, Sachiko; Moriyama, Masafumi; Miyake, Kensuke; Nakashima, Hitoshi; Tanaka, Akihiko; Maehara, Takashi; Iizuka-Koga, Mana; Tsuboi, Hiroto; Hayashida, Jun-Nosuke; Ishiguro, Noriko; Yamauchi, Masaki; Sumida, Takayuki; Nakamura, Seiji

    2017-01-01

    IgG4-related disease (IgG4-RD) is characterized by elevated serum IgG4 and marked infiltration of IgG4-positive cells in multiple organs. Interleukin-33 (IL-33) is a recently described cytokine that is secreted by damaged epithelial cells, macrophages, and dendritic cells, and potently activates helper T type 2 (Th2) immune responses, which have been suggested to play a major role in IgG4 production of IgG4-RD. Here, we assessed the expression of IL-33 and related molecules in the salivary glands (SGs) of patients with IgG4-RD versus that in patients with Sjögren’s syndrome (SS) and controls. Expression of IL-33 and its receptor (ST2) was strongly detected around ectopic germinal centers (GCs) in the SGs from patients with IgG4-RD, whereas IL-33 was expressed only in epithelial cells in patients with SS and controls. Moreover, IL-33 and CD68+/CD163+ macrophages were mainly distributed around ectopic GCs in patients with IgG4-RD. Double immunofluorescence staining showed that IL-33 expression co-localized with CD68+/CD163+ macrophages. Finally, mRNA expression levels of IL-33 showed a positive correlation to those of Th2 cytokines (IL-4 and IL-13) in patients with IgG4-RD. Our data suggest that IL-33 produced by M2 macrophages might contribute to the pathogenesis of IgG4-RD via aberrant activation of Th2 immune responses. PMID:28205524

  5. Passage from normal mucosa to adenoma and colon cancer: alteration of normal sCD30 mechanisms regulating TH1/TH2 cell functions.

    PubMed

    Contasta, Ida; Berghella, Anna Maria; Pellegrini, Patrizia; Adorno, Domenico

    2003-08-01

    The pathogenesis of cancer is currently under intensive investigation to identify reliable prognostic indices for the early detection of disease. Adenomas have been identified as precursors of colorectal cancer and tumor establishment, and disease progression has been found to reflect a malfunction of the immune system. On the basis of the role of the CD30 molecule in the regulation of TH1/TH2 functions and our previous results, strongly suggesting the validity of serum TH1/TH2 cytokines in the study of tumor progression, we studied network interaction between the production of soluble (s) CD30/sBCl2 in whole blood culture [in basic conditions and after PHA, LPS, and anti-CD3 monoclonal antibody (mAb) stimulation] and levels of TH1/TH2 cytokines (IL2, IFN gamma, IL12, IL4, IL5, IL10). Peripheral blood from a group of healthy subjects, as well as from patients with adenoma and colorectal cancer was used. Our objective was to gain a better insight into the role of the CD30 molecule in the passage from normal mucosa to adenoma and tumor and identify specific disease markers. Our results suggest that the decrease in CD30 expression and the abnormal increase in Bcl2 expression, observed in the peripheral cells of both adenoma and tumor groups determine an imbalance between TH1/TH2 functions. Consequently, changes in sCD30/sBcl2 culture production and TH1/TH2 cytokine serum levels may be reliable markers for tumor progression. In fact, our overall data show that a decrease of sCD30 levels in basic and PHA conditions and an increase of IFN gamma, IL4, IL5, and IL12 serum levels and sBcl2 in all activation condition are indicative of the passage from normal mucosa to adenoma; whilst a decrease of sBcl2 level in basic, LPS and anti-CD3 conditions and of IL2, IFN gamma serum levels, together with an increase of IL5 are indicative of the passage from adenoma to tumor.

  6. Proliferation and TH1/TH2 cytokine production in human peripheral blood mononuclear cells after treatment with cypermethrin and mancozeb in vitro.

    PubMed

    Mandarapu, Rajesh; Ajumeera, Rajanna; Venkatesan, Vijayalakshmi; Prakhya, Balakrishna Murthy

    2014-01-01

    In recent times, human cell-based assays are gaining attention in assessments of immunomodulatory effects of chemicals. In the study here, the possible effects of cypermethrin and mancozeb on lymphocyte proliferation and proinflammatory (tumor necrosis factor (TNF-) α) and immunoregulatory cytokine (interferon- (IFN-) γ, interleukins (IL) 2, 4, 6, and 10) formation in vitro were investigated. Human peripheral blood mononuclear cells (PBMC) were isolated and exposed for 6 hr to noncytotoxic doses (0.45-30 µM) of cypermethrin or mancozeb in the presence of activating rat S9 fraction. Cultures were then further incubated for 48 or 72 hr in fresh medium containing phytohemagglutinin (10 µg/mL) to assess, respectively, effects on cell proliferation (BrdU-ELISA method) and cytokine formation (flow cytometric bead immunoassays). Mancozeb induced dose-dependent increases in lymphocyte proliferation, inhibition of production of TNFα and the TH2 cytokines IL-6 and IL-10, and an increase in IFNγ (TH1 cytokine) production (at least 2-fold compared to control); mancozeb also induced inhibition of IL-4 (TH2) and stimulated IL-2 (TH1) production, albeit only in dose-related manners for each. In contrast, cypermethrin exposure did not cause significant effects on proliferation or cytokine profiles. Further studies are needed to better understand the functional significance of our in vitro findings.

  7. The Anti-Allergic Rhinitis Effect of Traditional Chinese Medicine of Shenqi by Regulating Mast Cell Degranulation and Th1/Th2 Cytokine Balance.

    PubMed

    Shao, Yang-Yang; Zhou, Yi-Ming; Hu, Min; Li, Jin-Ze; Chen, Cheng-Juan; Wang, Yong-Jiang; Shi, Xiao-Yun; Wang, Wen-Jie; Zhang, Tian-Tai

    2017-03-22

    Shenqi is a traditional Chinese polyherbal medicine has been widely used for the treatment of allergic rhinitis (AR). The aim of this study was to investigate the anti-allergic rhinitis activity of Shenqi and explore its underlying molecular mechanism. Ovalbumin (OVA)-induced allergic rhinitis rat model was used to evaluate the anti-allergic rhinitis effect of Shenqi. The effect of Shenqi on IgE-mediated degranulation was measured using rat basophilic leukemia (RBL-2H3) cells. Primary spleen lymphocytes were isolated to investigate the anti-allergic mechanism of Shenqi by detecting the expression of transcription factors via Western blot and the level of cytokines (IL-4 and IFN-γ) via ELISA. In OVA-induced AR rat models, Shenqi relieved the allergic rhinitis symptoms, inhibited the histopathological changes of nasal mucosa, and reduced the levels of IL-4 and IgE. The results from the in vitro study certified that Shenqi inhibited mast cell degranulation. Furthermore, the results of GATA3, T-bet, p-STAT6, and SOCS1 expression and production of IFN-γ and IL-4 demonstrated that Shenqi balanced the ratio of Th1/Th2 (IFN-γ/IL-4) in OVA-stimulated spleen lymphocytes. In conclusion, these results suggest that Shenqi exhibits an obvious anti-allergic effect by suppressing the mast cell-mediated allergic response and by improving the imbalance of Th1/Th2 ratio in allergic rhinitis.

  8. Ex vivo rapamycin generates Th1/Tc1 or Th2/Tc2 Effector T cells with enhanced in vivo function and differential sensitivity to post-transplant rapamycin therapy.

    PubMed

    Jung, Unsu; Foley, Jason E; Erdmann, Andreas A; Toda, Yoko; Borenstein, Todd; Mariotti, Jacopo; Fowler, Daniel H

    2006-09-01

    Rapamycin prevention of murine graft-versus-host disease (GVHD) is associated with a shift toward Th2- and Tc2-type cytokines. Recently, we found that use of rapamycin during ex vivo donor Th2 cell generation enhances the ability of adoptively transferred Th2 cells to prevent murine GVHD. In this study, using a method, without antigen-presenting cells, of T-cell expansion based on CD3,CD28 costimulation, we evaluated whether (1) rapamycin preferentially promotes the generation of Th2/Tc2 cells relative to Th1/Tc1 cells, (2) rapamycin-generated T-cell subsets induce cytokine skewing after allogeneic bone marrow transplantation (BMT), and (3) such in vivo cytokine skewing is sensitive to post-BMT rapamycin therapy. Contrary to our hypothesis, rapamycin did not preferentially promote Th2/Tc2 cell polarity, because rapamycin-generated Th1/Tc1 cells secreted type I cytokines (interleukin [IL]-2 and interferon-gamma) did not secrete type II cytokines (IL-4, IL-5, IL-10, or IL-13) and mediated fasL-based cytolysis. Rapamycin influenced T-cell differentiation, because each of the Th1, Th2, Tc1, and Tc2 subsets generated in rapamycin had increased expression of the central-memory T-cell marker, L-selectin (CD62L). Rapamycin-generated Th1/Tc1 and Th2/Tc2 cells were not anergic but instead had increased expansion after costimulation in vitro, increased expansion in vivo after BMT, and maintained full capacity to skew toward type I or II cytokines after BMT, respectively; further, rapamycin-generated Th1/Tc1 cells mediated increased lethal GVHD relative to control Th1/Tc1 cells. Rapamycin therapy after BMT in recipients of rapamycin-generated Th1/Tc1 cells greatly reduced Th1/Tc1 cell number, greatly reduced type I cytokines, and reduced lethal GVHD; in marked contrast, rapamycin therapy in recipients of rapamycin-generated Th2/Tc2 cells nominally influenced the number of Th2/Tc2 cells in vivo and did not abrogate post-BMT type II cytokine skewing. In conclusion, ex vivo and

  9. Selective development of T helper (Th)2 cells induced by continuous administration of low dose soluble proteins to normal and beta(2)- microglobulin-deficient BALB/c mice

    PubMed Central

    1996-01-01

    Continuous administration of soluble proteins, delivered over a 10-d period by a mini-osmotic pump implanted subcutaneously, induces a long- lasting inhibition of antigen-specific T cell proliferation in lymph node cells from BALB/c mice subsequently primed with antigen in adjuvant. The decreased T cell proliferative response is associated with a down-regulation of the T helper cell (Th)1 cytokines interleukin (IL)-2 and interferon (IFN)-gamma and with a strong increase in the secretion of the Th2 cytokines IL-4 and IL-5 by antigen specific CD4+ T cells. This is accompanied by predominant inhibition of antigen- specific antibody production of IgG2a and IgG2b, rather than IgG1 isotype. Interestingly, inhibition of Th1 and priming of Th2 cells is also induced in beta(2) microglobulin-deficient BALB/c mice, indicating that neither CD8+ nor CD4+ NK1.1+ T cells, respectively, are required. The polarization in Th2 cells is stably maintained by T cell lines, all composed of CD4+/CD8- cells expressing T cell receptor for antigen (TCR) alpha/beta chains, derived from BALB/c mice treated with continuous antigen administration, indicating that they originate from Th2 cells fully differentiated in vivo. This polarization is induced in BALB/c mice by continuous administration of any protein antigen tested, including soluble extracts from pathogenic microorganisms. Priming of Th2 cells is dose dependent and it is optimal for low rather than high doses of protein. Blocking endogenous IL-4 in vivo inhibits expansion of antigen-specific Th2 cells, but does not restore IFN-gamma production by T cells from mice treated with soluble antigen-specific Th2 cells, but does not restore IFN-gamma production by T cells from mice treated with soluble antigen, indicating the involvement of two independent mechanisms. Consistent with this, Th2 cell development, but not inhibition of Th1 cells, depends on non-major histocompatibility complex genetic predisposition, since the Th2 response is

  10. The bioactivity of teleost IL-6: IL-6 protein in orange-spotted grouper (Epinephelus coioides) induces Th2 cell differentiation pathway and antibody production.

    PubMed

    Chen, Hsin-Hung; Lin, Han-Tso; Foung, Yi-Fan; Han-You Lin, John

    2012-10-01

    Interleukin 6 (IL-6) is a protein secreted by T cells and macrophages and plays an important role in immune response. IL-6 regulates the proliferation and differentiation of T cells, and elicits immunoglobulin production in B cells. In this study, the cDNA il-6 (gil-6) sequence of the orange spotted grouper (Epinephelus coioides) was obtained. The deduced IL-6 (gIL-6) protein comprised 223 amino acids, the sequence shared approximately 30% similarity with mammalian IL-6, and between 47% and 69% similarity with other available teleost IL-6. The protein comprises the signal peptide, the IL-6 family signature, and conserved amino acid residues found in IL-6 sequences of other teleost. In order to understand the bioactivity and influence of gIL-6 on humoral immune response, recombinant gIL-6 (rgIL-6) synthesized by prokaryotes was injected into orange spotted groupers, and the immune-related gene expression at various times in various organs was observed. Our results revealed that the Th1 specific transcription factor t-bet was down-regulated and Th2 specific transcription factors gata3, and c-maf were up-regulated in immune organs, following IL-6 stimulation. Additionally, higher levels of igm mRNA and translated protein were detected in rgIL-6 stimulated fish. These results indicate that IL-6 in groupers regulates the differentiation of naїve T helper cells into Th2 cells and elicits the production of antibodies.

  11. Oral administration of an immunodominant T-cell epitope downregulates Th1/Th2 cytokines and prevents experimental myasthenia gravis

    PubMed Central

    Baggi, Fulvio; Andreetta, Francesca; Caspani, Elisabetta; Milani, Monica; Longhi, Renato; Mantegazza, Renato; Cornelio, Ferdinando; Antozzi, Carlo

    1999-01-01

    The mucosal administration of the native antigen or peptide fragments corresponding to immunodominant regions is effective in preventing or treating several T cell–dependent models of autoimmune disease. No data are yet available on oral tolerance with immunodominant T-cell peptides in experimental autoimmune myasthenia gravis (EAMG), an animal model of B cell–dependent disease. We report that oral administration of the T-cell epitope α146-162 of the Torpedo californica acetylcholine receptor (TAChR) α-subunit suppressed T-cell responses to AChR and ameliorated the disease in C57Bl/6 (B6) mice. Protection from EAMG was associated with reduced serum Ab’s to mouse AChR and reduced AChR loss in muscle. The effect of Tα146-162 feeding was specific; treatment with a control peptide did not affect EAMG manifestations. The protective effect induced by peptide Tα146-162 was mediated by reduced production of IFN-γ, IL-2, and IL-10 by TAChR-reactive cells, suggesting T-cell anergy. TGF-β–secreting Th3 cells did not seem to be involved in tolerance induction. We therefore demonstrate that feeding a single immunodominant epitope can prevent an Ab-mediated experimental model of autoimmune disease. PMID:10545527

  12. Kinetics and functional implications of Th1 and Th2 cytokine production following activation of peripheral blood mononuclear cells in primary culture.

    PubMed

    McHugh, S; Deighton, J; Rifkin, I; Ewan, P

    1996-06-01

    The importance of cytokine production in some disease processes is now widely recognized. To investigate temporal relationships between cytokines, we stimulated peripheral blood mononuclear cells (PBMC) in vitro using the T cell mitogen phytohemagglutinin (PHA) and various antigens chosen to induce predominantly Th1 (streptokinase: streptodornase or purified protein derivative) or Th2 (Dermatophagoides pteronyssinus, bee or wasp venom: allergens in sensitive subjects) responses. Cytokine production was measured by sensitive bioassays or enzyme-linked immunosorbent assays. Of the 30 subjects studied, 10 were normal and 20 individuals were allergic to either D. pteronyssinus (n = 10) or bee venom (n = 10) (examined before specific allergen immunotherapy). We examined the temporal profiles of a panel of cytokines produced in primary culture. In PHA-driven cultures, cytokines were found to be sequentially produced in the order interleukin (IL)-2, IL-4, IL-5, IL-3, interferon (IFN)-gamma, IL-10, IL-6, IL-12 and tumor necrosis factor (TNF)-alpha. The response to allergen in allergic patients was predominantly Th2 in nature, with the production of IL-4, IL-5, IL-6 and IL-10, but little or no IFN-gamma. IL-2, IL-3, TNF-alpha and IL-12 were also produced in low amounts. The response of both atopic and normal subjects to recall bacterial antigens was predominantly Th1, with high levels of IFN-gamma, IL-2 and TNF-alpha. The relevance of the order, amount and speed of production, characteristic kinetics (production, consumption, homeostatic regulation) and the cell source of the cytokines are discussed.

  13. The formation of titan cells in Cryptococcus neoformans depends on the mouse strain and correlates with induction of Th2-type responses.

    PubMed

    García-Barbazán, Irene; Trevijano-Contador, Nuria; Rueda, Cristina; de Andrés, Belén; Pérez-Tavárez, Raquel; Herrero-Fernández, Inés; Gaspar, María Luisa; Zaragoza, Oscar

    2016-01-01

    Cryptococcus neoformans is a pathogenic yeast that can form titan cells in the lungs, which are fungal cells of abnormal enlarged size. Little is known about the factors that trigger titan cells. In particular, it is not known how the host environment influences this transition. In this work, we describe the formation of titan cells in two mouse strains, CD1 and C57BL/6J. We found that the proportion of C. neoformans titan cells was significantly higher in C57BL/6J mice than in CD1. This higher proportion of titan cells was associated with a higher dissemination of the yeasts to the brain. Histology sections demonstrated eosinophilia in infected animals, although it was significantly lower in the CD1 mice which presented infiltration of lymphocytes. Both mouse strains presented infiltration of granulocytes, but the amount of eosinophils was higher in C57BL/6J. CD1 mice showed a significant accumulation of IFN-γ, TNF-α and IL17, while C57BL/BL mice had an increase in the anti-inflammatory cytokine IL-4. IgM antibodies to the polysaccharide capsule and total IgE were more abundant in the sera from C57BL/6J, confirming that these animals present a Th2-type response. We conclude that titan cell formation in C. neoformans depends, not only on microbe factors, but also on the host environment.

  14. Human Bone Marrow-derived Mesenchymal Stem Cells Induce Th2-Polarized Immune Response and Promote Endogenous Repair in Animal Models of Multiple Sclerosis

    PubMed Central

    Bai, L; Lennon, DP; Eaton, V; Maier, K; Caplan, AI; Miller, SD; Miller, RH

    2009-01-01

    Cell based therapies are attractive approaches to promote myelin repair. Recent studies demonstrated a reduction in disease burden in mice with EAE treated with mouse mesenchymal stem cells (MSCs). Here we demonstrated human bone marrow derived MSCs (BM-hMSCs) promote functional recovery in both chronic and relapsing-remitting models of mouse EAE, traced their migration into the injured CNS and assayed their ability to modulate disease progression and the host immune response. Injected BM-hMSCs accumulated in the CNS, reduced the extent of damage and increased oligodendrocyte lineage cells in lesion areas. The increase in oligodendrocytes in lesions may reflect BM-hMSC induced changes in neural fate determination since neurospheres from treated animals gave rise to more oligodendrocytes and less astrocytes than non-treated neurospheres. Host immune responses were also influenced by BM-hMSCs. Inflammatory T-cells including interferon gamma (IFN-γ) producing Th1 cells and IL-17 producing Th17 inflammatory cells and their associated cytokines were reduced along with concomitant increases in IL-4 producing Th2 cells and anti-inflammatory cytokines. Together these data suggest the BM-hMSCs represent a viable option for therapeutic approaches. PMID:19191336

  15. TLR4/MyD88-Induced CD11b+Gr-1intF4/80+ Non-Migratory Myeloid Cells Suppress Th2 Effector Function in the Lung

    PubMed Central

    Arora, Meenakshi; Poe, Stephanie L.; Oriss, Timothy B.; Krishnamoorthy, Nandini; Yarlagadda, Manohar; Wenzel, Sally E.; Billiar, Timothy R.; Ray, Anuradha; Ray, Prabir

    2010-01-01

    In humans, environmental exposure to a high dose of lipopolysaccharide (LPS) protects from allergic asthma the immunological underpinnings of which are not well understood. In mice, exposure to a high LPS dose blunted house dust mite-induced airway eosinophilia and Th2 cytokine production. While adoptively transferred Th2 cells induced allergic airway inflammation in control mice, they were unable to do so in LPS-exposed mice. LPS promoted the development of a CD11b+Gr1intF4/80+ lung-resident cell resembling myeloid-derived suppressor cells in a TLR4- and MyD88-dependent fashion that suppressed lung dendritic cell (DC)-mediated reactivation of primed Th2 cells. LPS effects switched from suppressive to stimulatory in MyD88-/- mice. Suppression of Th2 effector function was reversed by anti-IL-10 or inhibition of Arginase 1. Lineageneg bone marrow progenitor cells could be induced by LPS to develop into CD11b+Gr1intF4/80+ cells both in vivo and in vitro which when adoptively transferred suppressed allergen-induced airway inflammation in recipient mice. These data suggest that CD11b+Gr1intF4/80+ cells contribute to the protective effects of LPS in allergic asthma by tempering Th2 effector function in the tissue. PMID:20664577

  16. Bazex Syndrome in Lung Squamous Cell Carcinoma: High Expression of Epidermal Growth Factor Receptor in Lesional Keratinocytes with Th2 Immune Shift

    PubMed Central

    Amano, Maki; Hanafusa, Takaaki; Chikazawa, Sakiko; Ueno, Makiko; Namiki, Takeshi; Igawa, Ken; Miura, Keiko; Yokozeki, Hiroo

    2016-01-01

    An 82-year-old Japanese man was referred for detailed examination of hyperkeratotic erythematous plaques on his palms and soles for 6 months. Two weeks before his first visit, he had undergone lung lobectomy for right lung squamous cell carcinoma (SCC). Laboratory findings showed elevations of eosinophil counts, serum IgE, thymus and activation-regulated chemokine, SCC antigen, and soluble interleukin-2 receptor levels. Histological results of a skin biopsy involving the left palm showed psoriasiform dermatitis. Before lung lobectomy, the hyperkeratotic erythematous plaques on the palms and soles and the erythemas on the trunk and extremities were difficult to treat with topical steroids. After lobectomy, the skin symptoms dramatically and rapidly subsided with topical steroids. Therefore, we diagnosed Bazex syndrome (BS), also known as acrokeratosis paraneoplastica, as a paraneoplastic cutaneous disease in lung SCC. The mild eosinophilia subsided and levels of SCC antigen, IgE, and soluble interleukin-2 receptor were reduced. BS is a paraneoplastic cutaneous disease characterized by acral psoriasiform lesions associated with an underlying neoplasm. In a previous report, a shift to the Th2 immune condition was found in patients with non-small cell lung cancer, as shown in our patient. Epidermal growth factor receptor (EGFR) is also known as tumor growth factor-α receptor; it is increased in psoriatic keratinocytes. In our case, EGFR expression increased in lesional keratinocytes 2 weeks after surgery and decreased 4 weeks after surgery. We speculate that a shift to Th2 immune reactions in lung SCC may be the pathogenesis of BS, whereby lesional keratinocytes highly express EGFR in parallel with disease activity. PMID:28101024

  17. CD4-Transgenic Zebrafish Reveal Tissue-Resident Th2- and Regulatory T Cell-like Populations and Diverse Mononuclear Phagocytes.

    PubMed

    Dee, Christopher T; Nagaraju, Raghavendar T; Athanasiadis, Emmanouil I; Gray, Caroline; Fernandez Del Ama, Laura; Johnston, Simon A; Secombes, Christopher J; Cvejic, Ana; Hurlstone, Adam F L

    2016-11-01

    CD4(+) T cells are at the nexus of the innate and adaptive arms of the immune system. However, little is known about the evolutionary history of CD4(+) T cells, and it is unclear whether their differentiation into specialized subsets is conserved in early vertebrates. In this study, we have created transgenic zebrafish with vibrantly labeled CD4(+) cells allowing us to scrutinize the development and specialization of teleost CD4(+) leukocytes in vivo. We provide further evidence that CD4(+) macrophages have an ancient origin and had already emerged in bony fish. We demonstrate the utility of this zebrafish resource for interrogating the complex behavior of immune cells at cellular resolution by the imaging of intimate contacts between teleost CD4(+) T cells and mononuclear phagocytes. Most importantly, we reveal the conserved subspecialization of teleost CD4(+) T cells in vivo. We demonstrate that the ancient and specialized tissues of the gills contain a resident population of il-4/13b-expressing Th2-like cells, which do not coexpress il-4/13a Additionally, we identify a contrasting population of regulatory T cell-like cells resident in the zebrafish gut mucosa, in marked similarity to that found in the intestine of mammals. Finally, we show that, as in mammals, zebrafish CD4(+) T cells will infiltrate melanoma tumors and obtain a phenotype consistent with a type 2 immune microenvironment. We anticipate that this unique resource will prove invaluable for future investigation of T cell function in biomedical research, the development of vaccination and health management in aquaculture, and for further research into the evolution of adaptive immunity.

  18. Mesenchymal stem cell transplantation can restore lupus disease-associated miRNA expression and Th1/Th2 ratios in a murine model of SLE

    PubMed Central

    Choi, Eun Wha; Lee, MinJae; Song, Ji Woo; Shin, Il Seob; Kim, Sung Joo

    2016-01-01

    C3.MRL-Faslpr/J mice spontaneously develop high titers of anti-dsDNA, mild glomerular nephritis, and severe lymphoproliferation symptoms. This study aimed to compare the effects of long-term serial administration of human adipose tissue-derived mesenchymal stem cells (ASCs), and cyclophosphamide treatment in C3.MRL-Faslpr/J mice using a murine SLE model. C3.MRL-Faslpr/J mice were divided into saline (C), cyclophosphamide (Y), and ASC (H) treatment groups. Background-matched control C3H mice treated with saline (N) were also compared. The Y group showed the greatest improvement in disease parameters, but with damaged trabecular integrity. ASC transplantation reduced anti-dsDNA levels, glomerular C3 deposition and CD138 proportion significantly, without trabecular damage. Furthermore, both cyclophosphamide and ASC treatment significantly decreased the ratio of Th1/Th2 compared with the saline-treatment. The expression levels of miR-31-5p, miR-96-5p, miR-182-5p, miR-183-5p, and miR-379-5p were significantly higher, while those of miR150-5p were significantly lower in the C group than in the N group. The expression levels of miR-96-5p, miR-182-5p in the Y and H groups were significantly lower than in the C group. Thus, treatment with cyclophosphamide or ASC can change miRNAs and decrease miR-96-5p and miR-182-5p expression, as well as decreasing the CD138 proportion and the Th1/Th2 ratio, which might be involved in the therapeutic mechanism. PMID:27924862

  19. Transgenic expression of CXCR3 on T cells enhances susceptibility to cutaneous Leishmania major infection by inhibiting monocyte maturation and promoting a Th2 response.

    PubMed

    Oghumu, Steve; Stock, James C; Varikuti, Sanjay; Dong, Ran; Terrazas, Cesar; Edwards, Jessica A; Rappleye, Chad A; Holovatyk, Ariel; Sharpe, Arlene; Satoskar, Abhay R

    2015-01-01

    Cutaneous leishmaniasis, caused mainly by Leishmania major, an obligate intracellular parasite, is a disfiguring disease characterized by large skin lesions and is transmitted by a sand fly vector. We previously showed that the chemokine receptor CXCR3 plays a critical role in mediating resistance to cutaneous leishmaniasis caused by Leishmania major. Furthermore, T cells from L. major-susceptible BALB/c but not L. major-resistant C57BL/6 mice fail to efficiently upregulate CXCR3 upon activation. We therefore examined whether transgenic expression of CXCR3 on T cells would enhance resistance to L. major infection in susceptible BALB/c mice. We generated BALB/c and C57BL/6 transgenic mice, which constitutively overexpressed CXCR3 under a CD2 promoter, and then examined the outcomes with L. major infection. Contrary to our hypothesis, transgenic expression of CXCR3 (CXCR3(Tg)) on T cells of BALB/c mice resulted in increased lesion sizes and parasite burdens compared to wild-type (WT) littermates after L. major infection. Restimulated lymph node cells from L. major-infected BALB/c-CXCR3(Tg) mice produced more interleukin-4 (IL-4) and IL-10 and less gamma interferon (IFN-γ). Cells in draining lymph nodes from BALB/c-CXCR3(Tg) mice showed enhanced Th2 and reduced Th1 cell accumulation associated with increased neutrophils and inflammatory monocytes. However, monocytes displayed an immature phenotype which correlated with increased parasite burdens. Interestingly, transgenic expression of CXCR3 on T cells did not impact the outcome of L. major infection in C57BL/6 mice, which mounted a predominantly Th1 response and spontaneously resolved their infection similar to WT littermates. Our findings demonstrate that transgenic expression of CXCR3 on T cells increases susceptibility of BALB/c mice to L. major.

  20. Mycobacterium tuberculosis PE25/PPE41 protein complex induces activation and maturation of dendritic cells and drives Th2-biased immune responses.

    PubMed

    Chen, Wei; Bao, Yige; Chen, Xuerong; Burton, Jeremy; Gong, Xueli; Gu, Dongqing; Mi, Youjun; Bao, Lang

    2016-04-01

    Mycobacterium tuberculosis evades innate host immune responses by parasitizing macrophages and causes significant morbidity and mortality around the world. A mycobacterial antigen that can activate dendritic cells (DCs) and elicit effective host innate immune responses will be vital to the development of an effective TB vaccine. The M. tuberculosis genes PE25/PPE41 encode proteins which have been associated with evasion of the host immune response. We constructed a PE25/PPE41 complex gene via splicing by overlapping extension and expressed it successfully in E. coli. We investigated whether this protein complex could interact with DCs to induce effective host immune responses. The PE25/PPE41 protein complex induced maturation of isolated mouse DCs in vitro, increasing expression of cell surface markers (CD80, CD86 and MHC-II), thereby promoting Th2 polarization via secretion of pro-inflammatory cytokines IL-4 and IL-10. In addition, PE25/PPE41 protein complex-activated DCs induced proliferation of mouse CD4(+) and CD8(+) T cells, and a strong humoral response in immunized mice. The sera of five TB patients were also highly reactive to this antigen. These findings suggest that interaction of the PE25/PPE41 protein complex with DCs may be of great immunological significance.

  1. NK T cell-induced protection against diabetes in V alpha 14-J alpha 281 transgenic nonobese diabetic mice is associated with a Th2 shift circumscribed regionally to the islets and functionally to islet autoantigen.

    PubMed

    Laloux, V; Beaudoin, L; Jeske, D; Carnaud, C; Lehuen, A

    2001-03-15

    The onset of autoimmune diabetes is related to defective immune regulation. Recent studies have shown that NK T cells are deficient in number and function in both diabetic patients and nonobese diabetic (NOD) mice. NK T cells, which are CD1d restricted, express a TCR with an invariant V alpha 14-J alpha 281 chain and rapidly produce large amounts of cytokines. V alpha 14-J alpha 281 transgenic NOD mice have increased numbers of NK T cells and are protected against diabetes onset. In this study we analyzed where and how NK T cells interfere with the development of the anti-islet autoimmune response. NK T cells, which are usually rare in lymph nodes, are abundant in pancreatic lymph nodes and are also present in islets. IL-4 mRNA levels are increased and IFN-gamma mRNA levels decreased in islets from diabetes-free V alpha 14-J alpha 281 transgenic NOD mice; the IgG1/IgG2c ratio of autoantibodies against glutamic acid decarboxylase is also increased in these mice. Treatment with IL-12 (a pro-Th1 cytokine) or anti-IL-4 Ab abolishes the diabetes protection in V alpha 14-J alpha 281 NOD mice. The protection from diabetes conferred by NK T cells is thus associated with a Th2 shift within islets directed against autoantigen such as glutamic acid decarboxylase. Our findings also demonstrate the key role of IL-4.

  2. Pulmonary IL-17E (IL-25) production and IL-17RB+ myeloid cell-derived Th2 cytokine production are dependent upon stem cell factor-induced responses during chronic allergic pulmonary disease.

    PubMed

    Dolgachev, Vladislav; Petersen, Bryan C; Budelsky, Alison L; Berlin, Aaron A; Lukacs, Nicholas W

    2009-11-01

    In the present studies local neutralization of allergen-induced stem cell factor (SCF) leads to decreased production of Th2 cytokines, a reduction in inflammation, allergen-specific serum IgE/IgG1, and attenuation of severe asthma-like responses. The local blockade of pulmonary SCF also resulted in a significant reduction of IL-17E (IL-25). Sorted cell populations from the lung indicated that IL-25 was produced from c-kit(+) cells, whereas Th2 cytokine production was primarily from c-kit(-) cell populations. SCF stimulated c-kit(+) eosinophils produced IL-25, whereas bone marrow-derived mast cells did not. Using 4get mice that contain a IL-4-IRES-eGFP that when transcribed coexpress GFP and IL-4, our studies identified cells that comprised a CD11b(+), GR1(+), Ly6C(+/-), c-kit(-), CD4(-), CD11c(-), MHC class II(low) cell population as a source of IL-4 in the lung after chronic allergen challenge. In the bone marrow a similar cell was identified with approximately a third of the IL-4(+) cells also expressing c-kit(+). The pulmonary and bone marrow IL-4(+) cell populations were significantly reduced upon local pulmonary anti-SCF treatment. Subsequently, when IL-25R was examined during the chronic allergen responses the expression was found on the IL-4(+) myeloid cell population that expressed CD11b(+)GR1(+). Interestingly, the IL-25R(+) cells in the bone marrow were also all CD11b(+)GR1(+), similar to the lung cells, but they were also all c-kit(+), potentially suggesting a maturation of the bone marrow cell once it enters the lung and/or is stimulated by SCF. Overall, these studies suggest a complex relationship between SCF, bone marrow-derived IL-25-responsive myeloid cells, Th2 cytokines, and chronic allergic disease.

  3. Direct hydrocarbon fuel cells

    DOEpatents

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  4. Administration of TLR7 agonist, resiquimod, in different types of chicken induces a mixed Th1 and Th2 response in the peripheral blood mononuclear cells.

    PubMed

    Annamalai, Arunsaravanakumar; Ramakrishnan, Saravanan; Sachan, Swati; Sharma, Bal Krishan; Anand Kumar, B S; Kumar, Vimal; Badasara, Surendra Kumar; Kumar, Ajay; Saravanan, B C; Krishnaswamy, Narayanan

    2015-06-01

    This study evaluated the variation in immune response in peripheral blood mononuclear cells (PBMCs) of broiler, White Leghorn (WL) and Kadaknath breeds of chicken following administration of TLR7 agonist, resiquimod (R-848). Expression of different immune related genes viz., interferon-β (IFN-β), IFN-γ, IL-1β, IL-4, TLR7 and iNOS was assessed by quantitative real time PCR over a period of 24 h. The results indicated that there was a significant up-regulation in the relative expression of immune response genes post R-848 administration (P < 0.01). In conclusion, the transcriptional expression of IFN-β, IFN-γ, IL-1β, IL-4, iNOS and TLR7 genes in the PBMCs was significantly up-regulated over 24 h in broiler, WL and Kadaknath breeds of birds after the administration of R-848. Overall, R-848 induced a mixed Th1 and Th2 response in PBMCs of chicken origin ex vivo.

  5. Analysis of Cytokine Production by Peanut-Reactive T Cells Identifies Residual Th2 Effectors in Highly Allergic Children Who Received Peanut Oral Immunotherapy

    PubMed Central

    Wisniewski, Julia A.; Commins, Scott P.; Agrawal, Rachana; Hulse, Kathryn E.; Yu, Mingxi D.; Cronin, Julia; Heymann, Peter W.; Pomes, Anna; Platts-Mills, Thomas; Workman, Lisa; Woodfolk, Judith A.

    2015-01-01

    Background Only limited evidence is available regarding the cytokine repertoire of effector T cells associated with peanut allergy, and how these responses relate to IgE antibodies to peanut components. Objective To interrogate T-cell effector cytokine populations induced by Ara h 1 and Ara h 2 among peanut allergic (PA) children in the context of IgE, and to evaluate their modulation during oral immunotherapy (OIT). Methods Peanut-reactive effector T cells were analyzed in conjunction with specific IgE profiles in PA children using intracellular staining and multiplex assay. Cytokine-expressing T cell subpopulations were visualized using SPICE. Results Ara h 2 dominated the antibody response to peanut as judged by prevalence and quantity among a cohort of children with IgE to peanut. High IgE (>15 kUA/L) was almost exclusively associated with dual sensitization to Ara h 1 and Ara h 2, and was age-independent. Among PA children, IL-4-biased responses to both major allergens were induced, regardless of whether IgE antibodies to Ara h 1 were present. Among subjects receiving OIT in whom high IgE was maintained, Th2 reactivity to peanut components persisted despite clinical desensitization and modulation of allergen-specific immune parameters including augmented specific IgG4 antibodies, Th1 skewing and enhanced IL-10. The complexity of cytokine-positive subpopulations within peanut-reactive IL-4+ and IFN-γ+ T cells was similar to that observed in those who received no OIT, but was modified with extended therapy. Nonetheless, high Foxp3 expression was a distinguishing feature of peanut-reactive IL-4+ T cells irrespective of OIT, and a correlate of their ability to secrete type 2 cytokines. Conclusion Though total numbers of peanut-reactive IL-4+ and IFN-γ+ T cells are modulated by OIT in highly allergic children, complex T-cell populations with pathogenic potential persist in the presence of recognized immune markers of successful immunotherapy. [Clinical

  6. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for molecules associated with metabolism, signaling and regulation in central nervous system mixed glial cell cultures

    PubMed Central

    Lisak, Robert P; Benjamins, Joyce A; Bealmear, Beverly; Nedelkoska, Liljana; Studzinski, Diane; Retland, Ernest; Yao, Bin; Land, Susan

    2009-01-01

    Background Cytokines secreted by immune cells and activated glia play central roles in both the pathogenesis of and protection from damage to the central nervous system (CNS) in multiple sclerosis (MS). Methods We have used gene array analysis to identify the initial direct effects of cytokines on CNS glia by comparing changes in early gene expression in CNS glial cultures treated for 6 hours with cytokines typical of those secreted by Th1 and Th2 lymphocytes and monocyte/macrophages (M/M). Results In two previous papers, we summarized effects of these cytokines on immune-related molecules, and on neural and glial related proteins, including neurotrophins, growth factors and structural proteins. In this paper, we present the effects of the cytokines on molecules involved in metabolism, signaling and regulatory mechanisms in CNS glia. Many of the changes in gene expression were similar to those seen in ischemic preconditioning and in early inflammatory lesions in experimental autoimmune encephalomyelitis (EAE), related to ion homeostasis, mitochondrial function, neurotransmission, vitamin D metabolism and a variety of transcription factors and signaling pathways. Among the most prominent changes, all three cytokine mixtures markedly downregulated the dopamine D3 receptor, while Th1 and Th2 cytokines downregulated neuropeptide Y receptor 5. An unexpected finding was the large number of changes related to lipid metabolism, including several suggesting a switch from diacylglycerol to phosphatidyl inositol mediated signaling pathways. Using QRT-PCR we validated the results for regulation of genes for iNOS, arginase and P glycoprotein/multi-drug resistance protein 1 (MDR1) seen at 6 hours with microarray. Conclusion Each of the three cytokine mixtures differentially regulated gene expression related to metabolism and signaling that may play roles in the pathogenesis of MS, most notably with regard to mitochondrial function and neurotransmitter signaling in glia. PMID

  7. Effects of Psoraleae fructus and its major component psoralen on Th2 response in allergic asthma.

    PubMed

    Jin, Hualiang; Wang, Limin; Xu, Changqing; Li, Bei; Luo, Qingli; Wu, Jinfeng; Lv, Yubao; Wang, Genfa; Dong, Jingcheng

    2014-01-01

    This study is aimed to evaluate the effects of Psoraleae fructus (PF) on Th2 responses in a rat model of asthma in vivo and psoralen, a major constituent in PF, on Th2 responses in vitro. A rat model of asthma was established by sensitization and challenged with ovalbumin (OVA). Airway hyperresponsiveness was detected by direct airway resistance analysis. Lung tissues were examined for cell infiltration and mucus hypersecretion. Bronchoalveolar lavage fluid (BALF) was assessed for cytokine levels. In vitro study, Th2 cytokine production was evaluated in the culture supernatant of D10.G4.1 (D10 cells) followed by the determination of cell viability, meanwhile Th2 transcription factor GATA-3 expression in D10 cells was also determined. The oral administration of PF significantly reduced airway hyperresponsiveness (AHR) to aerosolized methacholine and decreased IL-4 and IL-13 levels in the BALF. Histological studies showed that PF markedly inhibited inflammatory infiltration and mucus secretion in the lung tissues. In vitro study, psoralen significantly suppressed Th2 cytokines of IL-4, IL-5 and IL-13 by ConA-stimulated D10 cells without inhibitory effect on cell viability. Furthermore, GATA-3 protein expression was also markedly reduced by psoralen. This study demonstrated that PF exhibited inhibitory effects on hyperresponsiveness and airway inflammation in a rat model of asthma, which was associated with the suppression of Th2 response. Psoralen, a major constituent of PF, has immunomodulatory properties on Th2 response in vitro, which indicated that psoralen might be a critical component of PF for its therapeutic effects.

  8. Expression pattern of transcription factors and intracellular cytokines reveals that clinically cured tuberculosis is accompanied by an increase in Mycobacterium-specific Th1, Th2, and Th17 cells.

    PubMed

    da Silva, Marcos V; Massaro Junior, Vladimir J; Machado, Juliana R; Silva, Djalma A A; Castellano, Lúcio R; Alexandre, Patricia B D; Rodrigues, Denise B R; Rodrigues, Virmondes

    2015-01-01

    Tuberculosis (TB) remains a major global health problem and is the second biggest cause of death by infectious disease worldwide. Here, we investigate in vitro the Th1, Th2, Th17, and Treg cytokines and transcriptional factors produced after Mycobacterium-specific antigen stimulation in patients with active pulmonary tuberculosis, clinically cured pulmonary tuberculosis, and healthy donors with a positive tuberculin skin test (TST+). Together, our data indicate that clinical cure after treatment increases the percentages of Mycobacterium-specific Th1, Th2, and Th17 cells compared with those found in active-TB and TST+ healthy donors. These results show that the host-parasite equilibrium in latent TB breaks in favor of the microorganism and that the subsequent clinical recovery posttreatment does not return the percentage levels of such cells to those observed in latent tuberculosis. Additionally, our results indicate that rather than showing an increase in the percentage of Mycobacterium-specific Tregs, active-TB patients display lower Th1 : Treg and Th17 : Treg ratios. These data, together with lower Th1 : Th2 and Th17 : Th2 ratios, may indicate a mechanism by which the breakdown of the host-parasite equilibrium leads to active-TB and changes in the repertoire of Mycobacterium-specific Th cells that are associated with clinical cure after treatment of pulmonary tuberculosis.

  9. Relationships between Th1 or Th2 iNKT Cell Activity and Structures of CD1d-Antigen Complexes: Meta-analysis of CD1d-Glycolipids Dynamics Simulations

    PubMed Central

    Laurent, Xavier; Renault, Nicolas; Farce, Amaury; Chavatte, Philippe; Hénon, Eric

    2014-01-01

    A number of potentially bioactive molecules can be found in nature. In particular, marine organisms are a valuable source of bioactive compounds. The activity of an α-galactosylceramide was first discovered in 1993 via screening of a Japanese marine sponge (Agelas mauritanius). Very rapidly, a synthetic glycololipid analogue of this natural molecule was discovered, called KRN7000. Associated with the CD1d protein, this α-galactosylceramide 1 (KRN7000) interacts with the T-cell antigen receptor to form a ternary complex that yields T helper (Th) 1 and Th2 responses with opposing effects. In our work, we carried out molecular dynamics simulations (11.5 µs in total) involving eight different ligands (conducted in triplicate) in an effort to find out correlation at the molecular level, if any, between chemical modulation of 1 and the orientation of the known biological response, Th1 or Th2. Comparative investigations of human versus mouse and Th1 versus Th2 data have been carried out. A large set of analysis tools was employed including free energy landscapes. One major result is the identification of a specific conformational state of the sugar polar head, which could be correlated, in the present study, to the biological Th2 biased response. These theoretical tools provide a structural basis for predicting the very different dynamical behaviors of α-glycosphingolipids in CD1d and might aid in the future design of new analogues of 1. PMID:25376021

  10. New drugs targeting Th2 lymphocytes in asthma

    PubMed Central

    Caramori, Gaetano; Groneberg, David; Ito, Kazuhiro; Casolari, Paolo; Adcock, Ian M; Papi, Alberto

    2008-01-01

    Asthma represents a profound worldwide public health problem. The most effective anti-asthmatic drugs currently available include inhaled β2-agonists and glucocorticoids and control asthma in about 90-95% of patients. The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term therapy. Although glucocorticoids are highly effective in controlling the inflammatory process in asthma, they appear to have little effect on the lower airway remodelling processes that appear to play a role in the pathophysiology of asthma at currently prescribed doses. The development of novel drugs may allow resolution of these changes. In addition, severe glucocorticoid-dependent and resistant asthma presents a great clinical burden and reducing the side-effects of glucocorticoids using novel steroid-sparing agents is needed. Furthermore, the mechanisms involved in the persistence of inflammation are poorly understood and the reasons why some patients have severe life threatening asthma and others have very mild disease are still unknown. Drug development for asthma has been directed at improving currently available drugs and findings new compounds that usually target the Th2-driven airway inflammatory response. Considering the apparently central role of T lymphocytes in the pathogenesis of asthma, drugs targeting disease-inducing Th2 cells are promising therapeutic strategies. However, although animal models of asthma suggest that this is feasible, the translation of these types of studies for the treatment of human asthma remains poor due to the limitations of the models currently used. The myriad of new compounds that are in development directed to modulate Th2 cells recruitment and/or activation will clarify in the near future the relative importance of these cells and their mediators in the complex interactions with the other pro-inflammatory/anti-inflammatory cells and mediators responsible of the different asthmatic

  11. The comparison of expression of cutaneous lymphocyte-associated antigen (CLA), and Th1- and Th2-associated antigens in mycosis fungoides and cutaneous lesions of adult T-cell leukemia/lymphoma.

    PubMed

    Yamaguchi, Takahiro; Ohshima, Koichi; Tsuchiya, Takeshi; Suehuji, Hiroaki; Karube, Kennosuke; Nakayama, Juichiro; Suzumiya, Junji; Yoshino, Tadashi; Kikuchi, Masahiro

    2003-01-01

    Mycosis fungoides (MF) is morphologically similar to cutaneous lesions of adult T cell leukemia/lymphoma (ATLL) of human T-cell lymphotropic virus-type I (HTLV-1). In addition, the Th1 or Th2 characteristic of MF and ATLL is still controversial. In the present study, to discriminate MF and cutaneous lesion of ATLL using immunohistochemical markers, and to elucidate Th1 or Th2 dominancy in both disorders, CLA (cutaneous lymphocyte associated antigen) was expressed on epidermotrophic lymphoma cells in all early stage MF. In contrast, all ATLL were negative for CLA. CXCR3 was especially expressed in epidermotropic small lymphoma cells of MF. CCR5 was expressed in both disorders with variable sized lymphoma cells. ST2 was expressed on large transformed lymphoma cells with ATLL, but not in any MF cases. OX40 was expressed in the large transformed cell population in both disorders. These findings suggest that CLA and ST2 could be potentially useful immunohistochemical markers for discrimination of mycosis fungoides and cutaneous lesions of ATLL. And OX40 could be a useful immunohistochemical marker for the histopathological progression of both disorders.

  12. p(⁷⁰S⁶K¹) in the TORC1 pathway is essential for the differentiation of Th17 Cells, but not Th1, Th2, or Treg cells in mice.

    PubMed

    Sasaki, Carl Y; Chen, Gang; Munk, Rachel; Eitan, Erez; Martindale, Jennifer; Longo, Dan L; Ghosh, Paritosh

    2016-01-01

    The TORC1 pathway is necessary for ribosomal biogenesis and initiation of protein translation. Furthermore, the differentiation of Th1 and Th17 cells requires TORC1 activity. To investigate the role of the TORC1 pathway in the differentiation of Th1 and/or Th17 cells in more detail, we compared the differentiation capacity of naïve T cells from wild type and p70(S6K1) knockout mice. Expression of many of the genes associated with Th17-cell differentiation, such as IL17a, IL17f, and IL-23R, were reduced in p70(S6K1) knockout mice. In contrast, the development of Th1, Th2, and Treg cells was unaffected in the absence of p70(S6K1) . Furthermore, expression of the major transcription factor in Th17-cell differentiation, retinoic acid receptor-related orphan receptor gamma T, remained unchanged. However, the acetylation of histone 3 at the promoters of IL17a and IL17f was reduced in the absence of p70(S6K1) . In accordance with the in vitro data, the kinetics, but not the development, of EAE was affected with the loss of p70(S6K1) expression. Collectively, our findings suggested that both in vitro and in vivo differentiation of Th17 cells were positively regulated by p70(S6K1) .

  13. Th2 and eosinophil responses suppress inflammatory arthritis

    PubMed Central

    Chen, Zhu; Andreev, Darja; Oeser, Katharina; Krljanac, Branislav; Hueber, Axel; Kleyer, Arnd; Voehringer, David; Schett, Georg; Bozec, Aline

    2016-01-01

    Th2–eosinophil immune responses are well known for mediating host defence against helminths. Herein we describe a function of Th2–eosinophil responses in counteracting the development of arthritis. In two independent models of arthritis, Nippostrongylus brasiliensis infection leads to Th2 and eosinophil accumulation in the joints associated with robust inhibition of arthritis and protection from bone loss. Mechanistically, this protective effect is dependent on IL-4/IL-13-induced STAT6 pathway. Furthermore, we show that eosinophils play a central role in the modulation of arthritis probably through the increase of anti-inflammatory macrophages into arthritic joints. The presence of these pathways in human disease is confirmed by detection of GATA3-positive cells and eosinophils in the joints of rheumatoid arthritis patients. Taken together, these results demonstrate that eosinophils and helminth-induced activation of the Th2 pathway axis effectively mitigate the course of inflammatory arthritis. PMID:27273006

  14. As2 O3 combined with leflunomide prolongs heart xenograft survival via suppressing the response of Th1, Th2, and B cells in a rat model.

    PubMed

    Jiao, Zhi-Xing; Leng, Yun; Xia, Jun-Jie; Wu, Hai-Qiao; Jin, Ning; Fu, Jia-Zhao; Cheng, Lian-Na; Wang, Jin-Hua; Ni, Shao-Bin; Qi, Zhong-Quan

    2016-05-01

    Xenotransplantation remits the severe shortage of human organs and tissues for transplantation, which is a problem that severely limits the application of transplantation to the treatment of human disease. However, severe immune rejection significantly limits the efficacy of xenotransplantation. In this study, we systematically investigated the immunosuppressive effect and mechanism of action of As2 O3 and leflunomide using a hamster-to-rat heart xenotransplantation model. We initially examined heart xenograft survival following As2 O3 and leflunomide treatment alone or combined treatment. We found that treatment with As2 O3 combined with leflunomide can significantly prolong the survival of heart xenograft by inhibiting Th1 and Th2 differentiation and reducing the production of IgG and IgM. Interestingly, As2 O3 and leflunomide showed low toxicity to the organs of the recipient. Taken together, these observations indicate that treatment with As2 O3 combined with leflunomide may be a promising immunosuppressive schedule for xenotransplantation.

  15. Constituents of the anti–asthma herbal formula ASHMI™ synergistically inhibit IL–4 and IL–5 secretion by murine Th2 memory cells, and eotaxin by human lung fibroblasts in vitro

    PubMed Central

    Jayaprakasam, Bolleddula; Yang, Nan; Wen, Ming-Chun; Wang, Rong; Goldfarb, Joseph; Sampson, Hugh; Li, Xiu-Min

    2015-01-01

    OBJECTIVE Anti-asthma herbal medicine intervention (ASHMI™), a combination of three traditional Chinese medicinal herbs developed in our laboratory, has demonstrated efficacy in both mouse models of allergic asthma, and a double-blind placebo-controlled clinical trial in patients with asthma. This study was designed to determine if the anti-inflammatory effects of individual herbal constituents of ASHMI™ exhibited synergy. METHODS Effects of ASHMI and its components aqueous extracts of Lingzhi (Ganoderma lucidum), Kushen (Sophora flavescens) and Gancao (Glycyrrhiza uralensis), on Th2 cytokine secretion by murine memory Th2 cells (D10.G4.1) and eotaxin-1 secretion by human lung fibroblast (HLF-1) cells were determined by measuring levels in culture supernatants by enzyme-linked immunosorbent assay. Potential synergistic effects were determined by computing interaction indices from concentration-effect curve parameters. RESULTS Individual Lingzhi, Kushen and Gancao extracts and ASHMI (the combination of individual extracts) inhibited production of interleukin (IL)-4 and IL-5 by murine memory Th2 cells and eotaxin-1 production by HLF-1 cells. The mean 25%-inhibitory-concentration (IC25) values (mg/mL) for ASHMI, Lingzhi, Kushen and Gancao for IL-4 production were 30.9, 79.4, 123, and 64.6, respectively; for IL-5 production were 30.2, 263, 123.2 and 100, respectively; for eotaxin-1 were 13.2, 16.2, 30.2, and 25.1, respectively. The IC50 values (mg/mL) for ASHMI, Lingzhi, Kushen and Gancao for IL-4 production were 158.5, 239.9, 446.7, and 281.8, respectively; for eotaxin-1 were 38.1, 33.1, 100, and 158.5, respectively. The interaction indices of ASHMI constituents at IC25 were 0.35 for IL-4, 0.21 for IL-5 and 0.59 for eotaxin-1. The interaction indices at IC50 values were 0.50 for IL-4 and 0.62 for eotaxin-1 inhibition. Inhibition of IL-5 did not reach IC50 values. All interaction indices were below 1 which indicated synergy. CONCLUSION By comparing the interaction

  16. Clinical association of baseline levels of conjugated dienes in low-density lipoprotein and nitric oxide with aggressive B-cell non-Hodgkin lymphoma and their relationship with immunoglobulins and Th1-to-Th2 ratio

    PubMed Central

    Haddouche, Mustapha; Meziane, Warda; Hadjidj, Zeyneb; Mesli, Naima; Aribi, Mourad

    2016-01-01

    Objective The aim of this study was to highlight the clinical association of baseline levels of conjugated dienes in low-density lipoprotein (LDL-BCD) and nitric oxide (NO) with immunoglobulins (Igs) and T helper (Th)1/Th2 ratio in patients with newly diagnosed B-cell non-Hodgkin lymphoma (NHL). Patients and methods Thirty-two newly diagnosed patients with aggressive B-cell NHL and 25 age-, sex-, and body-mass-index-matched healthy controls were randomly selected for a cross-sectional case–control study conducted at the Hematology Department of Tlemcen Medical Centre University (northwest of Algeria). Results Circulating levels of LDL-BCD and NO and those of IgA and IgM were significantly higher in patients than in controls. The levels of Th1/Th2 ratio and plasma total antioxidant capacity were significantly lower in patients compared with controls, while malondialdehyde and protein carbonyl levels were significantly higher in patients. B-cell NHL was significantly associated with high levels of LDL-BCD from 25th to 75th percentile (25th percentile: relative risk [RR] =2.26, 95% confidence interval [CI] 1.42–3.59, P=0.014; 50th percentile: RR =2.84, 95% CI 1.72–4.68, P<0.001; 75th percentile: RR =5.43, 95% CI 2.58–11.42, P<0.001). Similarly, the disease was significantly associated with high levels of NO production from 25th to 75th percentile (25th percentile: RR =2.07, 95% CI 1.25–3.44, P=0.024; 50th percentile: RR =2.78, 95% CI 1.63–4.72, P<0.001; 75th percentile: RR =4.68, 95% CI 2.21–9.91, P<0.001). Moreover, LDL-BCD levels were positively and significantly correlated with interferon (IFN)-γ, whereas NO levels were inversely and significantly correlated with IFN-γ and Th1/Th2 ratio. Conclusion LDL-BCD and NO production seem to be associated with aggressive B-cell NHL and alteration of Th1/Th2 ratio. Our results have to be examined using ex vivo mechanistic studies leading to further investigations of these parameters, with an interest in the

  17. Bach2–Batf interactions control Th2-type immune response by regulating the IL-4 amplification loop

    PubMed Central

    Kuwahara, Makoto; Ise, Wataru; Ochi, Mizuki; Suzuki, Junpei; Kometani, Kohei; Maruyama, Saho; Izumoto, Maya; Matsumoto, Akira; Takemori, Nobuaki; Takemori, Ayako; Shinoda, Kenta; Nakayama, Toshinori; Ohara, Osamu; Yasukawa, Masaki; Sawasaki, Tatsuya; Kurosaki, Tomohiro; Yamashita, Masakatsu

    2016-01-01

    Although Bach2 has an important role in regulating the Th2-type immune response, the underlying molecular mechanisms remain unclear. We herein demonstrate that Bach2 associates with Batf and binds to the regulatory regions of the Th2 cytokine gene loci. The Bach2–Batf complex antagonizes the recruitment of the Batf–Irf4 complex to AP-1 motifs and suppresses Th2 cytokine production. Furthermore, we find that Bach2 regulates the Batf and Batf3 expressions via two distinct pathways. First, Bach2 suppresses the maintenance of the Batf and Batf3 expression through the inhibition of IL-4 production. Second, the Bach2–Batf complex directly binds to the Batf and Batf3 gene loci and reduces transcription by interfering with the Batf–Irf4 complex. These findings suggest that IL-4 and Batf form a positive feedback amplification loop to induce Th2 cell differentiation and the subsequent Th2-type immune response, and Bach2–Batf interactions are required to prevent an excessive Th2 response. PMID:27581382

  18. Selective Th2 Upregulation by Crocus sativus: A Neutraceutical Spice

    PubMed Central

    Bani, Sarang; Pandey, Anjali; Agnihotri, Vijai K.; Pathania, Vijaylata; Singh, Bikram

    2011-01-01

    The immunomodulatory activity of an Indian neutraceutical spice, saffron (Crocus sativus) was studied on Th1 and Th2 limbs of the immune system. Oral administration of alcoholic extract of Crocus sativus (ACS) at graded dose levels from 1.56–50 mg/kg p.o. potentiated the Th2 response of humoral immunity causing the significant increases in agglutinating antibody titre in mice at a dose of 6.25 mg/kg and an elevation of CD19+ B cells and IL-4 cytokine, a signature cytokine of Th2 pathway. Appreciable elevation in levels of IgG-1 and IgM antibodies of the primary and secondary immune response was observed. However, ACS showed no appreciable expression of the Th1 cytokines IL-2 (growth factor for CD4+ T cells) and IFN-γ (signature cytokine of Th1 response). A significant modulation of immune reactivity was observed in all the animal models used. This paper represents the selective upregulation of the Th2 response of the test material and suggests its use for subsequent selective Th2 immunomodulation. PMID:20953384

  19. A rice-based edible vaccine expressing multiple T cell epitopes induces oral tolerance for inhibition of Th2-mediated IgE responses.

    PubMed

    Takagi, Hidenori; Hiroi, Takachika; Yang, Lijun; Tada, Yoshifumi; Yuki, Yoshikazu; Takamura, Kaoru; Ishimitsu, Ryotaro; Kawauchi, Hideyuki; Kiyono, Hiroshi; Takaiwa, Fumio

    2005-11-29

    Peptide immunotherapy using multiple predominant allergen-specific T cell epitopes is a safe and promising strategy for the control of type I allergy. In this study, we developed transgenic rice plants expressing mouse dominant T cell epitope peptides of Cry j I and Cry j II allergens of Japanese cedar pollen as a fusion protein with the soybean seed storage protein glycinin. Under the control of the rice seed storage protein glutelin GluB-1 promoter, the fusion protein was specifically expressed and accumulated in seeds at a level of 0.5% of the total seed protein. Oral feeding to mice of transgenic rice seeds expressing the T cell epitope peptides of Cry j I and Cry j II before systemic challenge with total protein of cedar pollen inhibited the development of allergen-specific serum IgE and IgG antibody and CD4(+) T cell proliferative responses. The levels of allergen-specific CD4(+) T cell-derived allergy-associated T helper 2 cytokine production of IL-4, IL-5, and IL-13 and histamine release in serum were significantly decreased. Moreover, the development of pollen-induced clinical symptoms was inhibited in our experimental sneezing mouse model. These results indicate the potential of transgenic rice seeds in production and mucosal delivery of allergen-specific T cell epitope peptides for the induction of oral tolerance to pollen allergens.

  20. Effect of nutrient deficiencies on in vitro Th1 and Th2 cytokine response of peripheral blood mononuclear cells to Plasmodium falciparum infection

    PubMed Central

    2010-01-01

    Background An appropriate balance between pro-inflammatory and anti-inflammatory cytokines that mediate innate and adaptive immune responses is required for effective protection against human malaria and to avoid immunopathology. In malaria endemic countries, this immunological balance may be influenced by micronutrient deficiencies. Methods Peripheral blood mononuclear cells from Tanzanian preschool children were stimulated in vitro with Plasmodium falciparum-parasitized red blood cells to determine T-cell responses to malaria under different conditions of nutrient deficiencies and malaria status. Results The data obtained indicate that zinc deficiency is associated with an increase in TNF response by 37%; 95% CI: 14% to 118% and IFN-γ response by 74%; 95% CI: 24% to 297%. Magnesium deficiency, on the other hand, was associated with an increase in production of IL-13 by 80%; 95% CI: 31% to 371% and a reduction in IFN-γ production. These results reflect a shift in cytokine profile to a more type I cytokine profile and cell-cell mediated responses in zinc deficiency and a type II response in magnesium deficiency. The data also reveal a non-specific decrease in cytokine production in children due to iron deficiency anaemia that is largely associated with malaria infection status. Conclusions The pathological sequels of malaria potentially depend more on the balance between type I and type II cytokine responses than on absolute suppression of these cytokines and this balance may be influenced by a combination of micronutrient deficiencies and malaria status. PMID:20546583

  1. Correlation of TLR2 and TLR4 expressions in peripheral blood mononuclear cells to Th1- and Th2-type immune responses in children with henoch-schönlein purpura.

    PubMed

    Chang, Hong; Zhang, Qiu-Ye; Lin, Yi; Cheng, Na; Zhang, Shou-Qing

    2015-01-01

    We discussed the correlation of TLR2 (Toll-like receptor) and TLR4 expressions in peripheral blood mononuclear cells (PBMCs) to Th1- and Th2-type immune responses in children with Henoch-Schönlein Purpura (HSP). The role of TLR2 and TLR4 in the pathogenesis of HSP was analyzed. Sixty-four HSP children treated at our hospital from October 2011 to November 2012 were enrolled and divided into NHSPN group (complicated by renal impairment, 36 cases) and HSPN group (not complicated by renal impairment, 28 cases). In the meantime, 30 normal children receiving physical examination at our hospital were recruited as controls. Peripheral blood T cell subgroups and TLR2 and TLR4 expressions in PBMCs were detected by using flow cytometry; relative expression levels of TLR2 and TLR4 mRNA in PBMCs by real-time quantitative fluorescence PCR, and plasma levels of IFN-γ, IL-4 and IL-6 by ELISA method. Relative expression levels of TLR2 and TLR4 mRNAs in PBMCs and TLR2 and TLR4 protein expressions in children with HSP were significantly higher than those of the controls (P<0.01). The relative expression levels of TLR2 and TLR4 mRNAs in PBMCs and TLR2 and TLR4 protein expressions in HSPN group were obviously higher than those in NHSPN group (P<0.05; P<0.01; P<0.01; P<0.01); CD3(+) T cells and CD3(+)CD4(+) T cells in HSP group were significantly decreased, while CD3(+)CD8(+) T cells and CD3(+)HLADR(+) T activated cells were considerably increased (P<0.01); The plasma levels of IL-4 and IL-6 in HSP group were significantly higher than those of the normal controls (P<0.01, P<0.01); IFN-γ level in the former was much lower than in the control group (P<0.05); IFN-γ/IL-4 ratio in the former was also lower than that in the control (P<0.01); TLR2 and TLR4 expressions in HSP group showed significantly positive correlation with the plasma levels of IL-4 and IL-6 (P<0.01, P<0.05; P<0.01, P<0.01) and significantly negative correlation with IFN-γ/IL-4 ratio (P<0.01; P<0.01). TLR2 and TLR4

  2. So-Cheong-Ryong-Tang, tradititional Korean medicine, suppresses Th2 lineage development.

    PubMed

    Ko, Eunjung; Rho, Samwoong; Cho, Chongwoon; Choi, Hyun; Ko, Seonggyu; Lee, Youngwon; Hong, Moo-Chang; Shin, Min-Kyu; Jung, Seung-Gi; Bae, Hyunsu

    2004-05-01

    The present study was designed to evaluate the effect of So-Cheong-Ryong-Tang (SCRT, also called Sho-Seiryu-To or Xiao-Qing-Long-Tang) on helper T cell development by monitoring Th1/Th2-specific cytokine secretion patterns in artificially induced Th1 or Th2 polarized conditions. The results demonstrated that Th2 cells were dramatically underpopulated in the Th2-driven condition triggered by SCRT treatment, while the Th1 cells were not altered in the Th1-skewed condition. Furthermore, under Th2-skewed conditions the levels of interleukin-4 were considerably decreased with SCRT treatment. The expression of GATA-3, a transcription factor that plays a pivotal role in Th2 lineage programming, did not change with SCRT treatment, while the expression of another Th2 transcription factor, c-Maf, was dramatically suppressed. These data suggest that SCRT modulates Th2 development by suppressing c-Maf expression. This study implies that the SCRT effect on CD4(+) T cells is a key pharmacologic point of effect for treating IgE-mediated allergic asthma. These results also suggest that SCRT might be a useful agent for the correction of Th2-dominant pathologic disorders.

  3. Protrusion Fluctuations Direct Cell Motion

    PubMed Central

    Caballero, David; Voituriez, Raphaël; Riveline, Daniel

    2014-01-01

    Many physiological phenomena involve directional cell migration. It is usually attributed to chemical gradients in vivo. Recently, other cues have been shown to guide cells in vitro, including stiffness/adhesion gradients or micropatterned adhesive motifs. However, the cellular mechanism leading to these biased migrations remains unknown, and, often, even the direction of motion is unpredictable. In this study, we show the key role of fluctuating protrusions on ratchet-like structures in driving NIH3T3 cell migration. We identified the concept of efficient protrusion and an associated direction index. Our analysis of the protrusion statistics facilitated the quantitative prediction of cell trajectories in all investigated conditions. We varied the external cues by changing the adhesive patterns. We also modified the internal cues using drug treatments, which modified the protrusion activity. Stochasticity affects the short- and long-term steps. We developed a theoretical model showing that an asymmetry in the protrusion fluctuations is sufficient for predicting all measures associated with the long-term motion, which can be described as a biased persistent random walk. PMID:24988339

  4. Th1, Th2 and Treg/T17 cytokines in two types of proliferative glomerulonephritis

    PubMed Central

    Stangou, M.; Bantis, C.; Skoularopoulou, M.; Korelidou, L.; Kouloukouriotou, D.; Scina, M.; Labropoulou, I. T.; Kouri, N. M.; Papagianni, A.; Efstratiadis, G.

    2016-01-01

    IgA nephropathy (IgAN) and focal segmental necrotizing glomerulonephritis (FSNGN) are characterized by proliferation of native glomerular cells and infiltration by inflammatory cells. Several cytokines act as mediators of kidney damage in both diseases. The aim of the present study was to investigate the role of Th1, Th2 and Treg/T17 cytokines in these types of proliferative glomerulonephritis. Simultaneous measurement of Th1 interleukin (IL-2, IL-12, tumor necrosis factor-alpha [TNF-α], interferon-gamma [INF-γ]), Th2 (IL-4, IL-5, IL-6, IL-10, IL-13), Treg/T17 transforming growth factor-beta 1 (TGF-β1, granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-17) cytokines and C-C chemokines Monocyte chemoattractant protein-1 (MCP-1, macrophage inflammatory protein-1 [MIP-1] β) was performed in first-morning urine samples, at the day of renal biopsy, using a multiplex cytokine assay. Cytokine concentrations were correlated with histological findings and renal function outcome. Urinary excretion of Th1, Th2 and Treg/Th17 cytokines were significantly higher in FSNGN compared to IgAN patients. In IgAN patients (n = 50, M/F: 36/14, M age: 40.7 [17–67] years), Th1, Th2 and T17 cytokines correlated significantly with the presence of endocapillary proliferation, while in FSNGN patients (n = 40, M/F: 24/16, M age: 56.5 [25–80] years), MCP-1 and TGF-β1 had a positive correlation with severe extracapillary proliferation (P = 0.001 and P = 0.002, respectively). Urinary IL-17 was the only independent parameter associated with endocapillary proliferation in IgAN and with MCP-1 urinary excretion in FSNGN. Response to treatment was mainly predicted by IL-6 in IgAN, and by Th2 (IL-4, IL-6), Treg (GM-CSF) cytokines and MIP-1 β in FSNGN. Th1, Th2 and T17 cytokines were directly implicated in renal pathology in IgAN and possibly through MCP-1 production in FSNGN. IL-17 and IL-6 seem to have a central role in inflammation and progression of kidney injury. PMID:27194829

  5. The direct methanol fuel cell

    SciTech Connect

    Halpert, G.; Narayanan, S.R.; Frank, H.

    1995-08-01

    This presentation describes the approach and progress in the ARPA-sponsored effort to develop a Direct Methanol, Liquid-Feed Fuel Cell (DMLFFC) with a solid Polymer Electrolyte Membrane (PEM) for battery replacement in small portable applications. Using Membrane Electrode Assemblies (MEAs) developed by JPL and Giner, significant voltage was demonstrated at relatively high current densities. The DMLFFC utilizes a 3 percent aqueous solution of methanol that is oxidized directly in the anode (fuel) chamber and oxygen (air) in the cathode chamber to produce water and significant power. The only products are water and CO{sub 2}. The ARPA effort is aimed at replacing the battery in the BA 5590 military radio.

  6. Plasticity of Migrating CD1b+ and CD1b- Lymph Dendritic Cells in the Promotion of Th1, Th2 and Th17 in Response to Salmonella and Helminth Secretions

    PubMed Central

    Olivier, Michel; Foret, Benjamin; Le Vern, Yves; Kerboeuf, Dominique; Guilloteau, Laurence A.

    2013-01-01

    Dendritic cells (DCs) are pivotal in the development of specific T-cell responses to control pathogens, as they govern both the initiation and the polarization of adaptive immunity. To investigate the capacities of migrating DCs to respond to pathogens, we used physiologically generated lymph DCs (L-DCs). The flexible polarization of L-DCs was analysed in response to Salmonella or helminth secretions known to induce different T cell responses. Mature conventional CD1b+ L-DCs showed a predisposition to promote pro-inflammatory (IL-6), pro-Th1 (IL-12p40) and anti-inflammatory (IL-10) responses which were amplified by Salmonella, and limited to only IL-6 induction by helminth secretions. The other major population of L-DCs did not express the CD1b molecule and displayed phenotypic features of immaturity compared to CD1b+ L-DCs. Salmonella infection reduced the constitutive expression of TNF-α and IL-4 mRNA in CD1b- L-DCs, whereas this expression was not affected by helminth secretions. The cytokine response of T cells promoted by L-DCs was analysed in T cell subsets after co-culture with Salmonella or helminth secretion-driven CD1b+ or CD1b- L-DCs. T cells preferentially expressed the IL-17 gene, and to a lesser extent the IFN-γ and IL-10 genes, in response to Salmonella-driven CD1b+ L-DCs, whereas a preferential IL-10, IFN-γ and IL-17 gene expression was observed in response to Salmonella-driven CD1b- L-DCs. In contrast, a predominant IL-4 and IL-13 gene expression by CD4+ and CD8+ T cells was observed after stimulation of CD1b+ and CD1b- L-DCs with helminth secretions. These results show that mature conventional CD1b+ L-DCs maintain a flexible capacity to respond differently to pathogens, that the predisposition of CD1b- L-DCs to promote a Th2 response can be oriented towards other Th responses, and finally that the modulation of migrating L-DCs responses is controlled more by the pathogen encountered than the L-DC subsets. PMID:24223964

  7. TPL-2 Regulates Macrophage Lipid Metabolism and M2 Differentiation to Control TH2-Mediated Immunopathology

    PubMed Central

    Entwistle, Lewis J.; Khoury, Hania; Papoutsopoulou, Stamatia; Mahmood, Radma; Mansour, Nuha R.; Ching-Cheng Huang, Stanley; Pearce, Edward J.; Pedro S. de Carvalho, Luiz; Ley, Steven C.

    2016-01-01

    Persistent TH2 cytokine responses following chronic helminth infections can often lead to the development of tissue pathology and fibrotic scarring. Despite a good understanding of the cellular mechanisms involved in fibrogenesis, there are very few therapeutic options available, highlighting a significant medical need and gap in our understanding of the molecular mechanisms of TH2-mediated immunopathology. In this study, we found that the Map3 kinase, TPL-2 (Map3k8; Cot) regulated TH2-mediated intestinal, hepatic and pulmonary immunopathology following Schistosoma mansoni infection or S. mansoni egg injection. Elevated inflammation, TH2 cell responses and exacerbated fibrosis in Map3k8–/–mice was observed in mice with myeloid cell-specific (LysM) deletion of Map3k8, but not CD4 cell-specific deletion of Map3k8, indicating that TPL-2 regulated myeloid cell function to limit TH2-mediated immunopathology. Transcriptional and metabolic assays of Map3k8–/–M2 macrophages identified that TPL-2 was required for lipolysis, M2 macrophage activation and the expression of a variety of genes involved in immuno-regulatory and pro-fibrotic pathways. Taken together this study identified that TPL-2 regulated TH2-mediated inflammation by supporting lipolysis and M2 macrophage activation, preventing TH2 cell expansion and downstream immunopathology and fibrosis. PMID:27487182

  8. Direct methanol fuel cell for portable applications

    SciTech Connect

    Valdez, T.I.; Narayanan, S.R.; Frank, H.; Chun, W.

    1997-12-01

    A five cell direct methanol fuel cell stack has been developed at the Jet Propulsion Laboratory. Presently direct methanol fuel cell technology is being incorporated into a system for portable applications. Electrochemical performance and its dependence on flow rate and temperature for a five cell stack are presented. Water transport data, and water transport mechanisms for direct methanol fuel cells are discussed. Stack response to pulse loads has been characterized. Implications of stack performance and operating conditions on system design have been addressed.

  9. Directional Summation in Non-direction Selective Retinal Ganglion Cells

    PubMed Central

    Abbas, Syed Y.; Hamade, Khaldoun C.; Yang, Ellen J.; Nawy, Scott; Smith, Robert G.; Pettit, Diana L.

    2013-01-01

    Retinal ganglion cells receive inputs from multiple bipolar cells which must be integrated before a decision to fire is made. Theoretical studies have provided clues about how this integration is accomplished but have not directly determined the rules regulating summation of closely timed inputs along single or multiple dendrites. Here we have examined dendritic summation of multiple inputs along On ganglion cell dendrites in whole mount rat retina. We activated inputs at targeted locations by uncaging glutamate sequentially to generate apparent motion along On ganglion cell dendrites in whole mount retina. Summation was directional and dependent13 on input sequence. Input moving away from the soma (centrifugal) resulted in supralinear summation, while activation sequences moving toward the soma (centripetal) were linear. Enhanced summation for centrifugal activation was robust as it was also observed in cultured retinal ganglion cells. This directional summation was dependent on hyperpolarization activated cyclic nucleotide-gated (HCN) channels as blockade with ZD7288 eliminated directionality. A computational model confirms that activation of HCN channels can override a preference for centripetal summation expected from cell anatomy. This type of direction selectivity could play a role in coding movement similar to the axial selectivity seen in locust ganglion cells which detect looming stimuli. More generally, these results suggest that non-directional retinal ganglion cells can discriminate between input sequences independent of the retina network. PMID:23516351

  10. Air Breathing Direct Methanol Fuel Cell

    DOEpatents

    Ren; Xiaoming

    2003-07-22

    A method for activating a membrane electrode assembly for a direct methanol fuel cell is disclosed. The method comprises operating the fuel cell with humidified hydrogen as the fuel followed by running the fuel cell with methanol as the fuel.

  11. Signals for the execution of Th2 effector function.

    PubMed

    Fowell, Deborah J

    2009-04-01

    Appropriate control of infection depends on the generation of lymphocytes armed with a particular array of cytokine and chemokine effector molecules. The differentiation of naïve T cells into functionally distinct effector subsets is regulated by signals from the T cell receptor (TCR) and cytokine receptors. Using gene knock-out approaches, the initiation of discrete effector programs appears differentially sensitive to the loss of individual TCR signaling components; likely due to differences in the transcription factors needed to activate individual cytokine genes. Less well understood however, are the signal requirements for the execution of effector function. With a focus on Th2 cells and the kinase ITK, we review recent observations that point to differences between the signals needed for the initiation and implementation of cytokine programs in CD4+ T cells. Indeed, Th2 effector cells signal differently from both their naïve counterparts and from Th1 effectors suggesting they may transduce activation signals differently or may be selectively receptive to different activation signals. Potential regulation points for effector function lie at the level of transcription and translation of cytokine genes. We also discuss how provision of these execution signals may be spatially segregated in vivo occurring at tissue sites of inflammation and subject to modulation by the pathogen itself.

  12. Development of chronic allergic responses by dampening Bcl6-mediated suppressor activity in memory T helper 2 cells.

    PubMed

    Ogasawara, Takashi; Hatano, Masahiko; Satake, Hisae; Ikari, Jun; Taniguchi, Toshibumi; Tsuruoka, Nobuhide; Watanabe-Takano, Haruko; Fujimura, Lisa; Sakamoto, Akemi; Hirata, Hirokuni; Sugiyama, Kumiya; Fukushima, Yasutsugu; Nakae, Susumu; Matsumoto, Kenji; Saito, Hirohisa; Fukuda, Takeshi; Kurasawa, Kazuhiro; Tatsumi, Koichiro; Tokuhisa, Takeshi; Arima, Masafumi

    2017-01-31

    Mice deficient in the transcriptional repressor B-cell CLL/lymphoma 6 (Bcl6) exhibit similar T helper 2 (TH2) immune responses as patients with allergic diseases. However, the molecular mechanisms underlying Bcl6-directed regulation of TH2 cytokine genes remain unclear. We identified multiple Bcl6/STAT binding sites (BSs) in TH2 cytokine gene loci. We found that Bcl6 is modestly associated with the BSs, and it had no significant effect on cytokine production in newly differentiated TH2 cells. Contrarily, in memory TH2 (mTH2) cells derived from adaptively transferred TH2 effectors, Bcl6 outcompeted STAT5 for binding to TH2 cytokine gene loci, particularly Interleukin4 (Il4) loci, and attenuated GATA binding protein 3 (GATA3) binding to highly conserved intron enhancer regions in mTH2 cells. Bcl6 suppressed cytokine production epigenetically in mTH2 cells to negatively tune histone acetylation at TH2 cytokine gene loci, including Il4 loci. In addition, IL-33, a pro-TH2 cytokine, diminished Bcl6's association with loci to which GATA3 recruitment was inversely augmented, resulting in altered IL-4, but not IL-5 and IL-13, production in mTH2 cells but no altered production in newly differentiated TH2 cells. Use of a murine asthma model that generates high levels of pro-TH2 cytokines, such as IL-33, suggested that the suppressive function of Bcl6 in mTH2 cells is abolished in severe asthma. These findings indicate a role of the interaction between TH2-promoting factors and Bcl6 in promoting appropriate IL-4 production in mTH2 cells and suggest that chronic allergic diseases involve the TH2-promoting factor-mediated functional breakdown of Bcl6, resulting in allergy exacerbation.

  13. DIRECT AMMONIA-AIR FUEL CELL.

    DTIC Science & Technology

    Experimental runs were conducted on direct ammonia fuel cells . Effects of temperature, composition, as well as run effect and block effect were...cells and to electrode flooding are discussed. Data on performance of complete laboratory direct ammonia-oxygen fuel cells are presented and discussed. (Author)

  14. Stem cell directed gene therapy.

    PubMed

    Engel, B C; Kohn, D B

    1999-05-01

    A potential therapeutic approach to HIV-1 infection is the genetic modification of cells of a patient to make them resistant to HIV-1. Hematopoietic stem cells are an attractive target for gene therapy of AIDS because of their ability to generate a broad repertoire of mature T lymphocytes, as well as the monocytic cells (macrophages, dendritic cells and microglia) which are also involved in HIV-1 pathogenesis. A number of synthetic "anti-HIV-1 genes" have been developed which inhibit HIV-1 replication. However, current methods for gene transfer into human hematopoietic stem cells, using retroviral vectors derived from the Moloney murine leukemia virus, have been minimally effective. Clinical trials performed to date in which hematopoietic cells from HIV-1-positive patients have been transduced with retroviral vectors and then reinfused have produced low to undetectable levels of gene-containing peripheral blood leukocytes. New vector delivery systems, such as lentiviral vectors, need to be developed to ensure efficient gene transfer and persistent transgene expression to provide life-long resistance to the cells targeted by HIV-1.

  15. Random versus directionally persistent cell migration

    PubMed Central

    Petrie, Ryan J.; Doyle, Andrew D.; Yamada, Kenneth M.

    2009-01-01

    Directional migration is an important component of cell motility. Although the basic mechanisms of random cell movement are well characterized, no single model explains the complex regulation of directional migration. Multiple factors operate at each step of cell migration to stabilize lamellipodia and maintain directional migration. Factors such as topography of the extracellular matrix, the cellular polarity machinery, receptor signalling, integrin trafficking and co-receptors, and actin–myosin contraction converge on regulation of the Rho family of GTPases and control of lamellipodial protrusions to promote directional migration. PMID:19603038

  16. Gold and d-penicillamine induce vasculitis and up-regulate mRNA for IL-4 in the Brown Norway rat: support for a role for Th2 cell activity

    PubMed Central

    QASIM, F J; THIRU, S; GILLESPIE, K

    1997-01-01

    d-penicillamine (DP) and gold salts which are used as immune-modulating agents in the treatment of rheumatoid arthritis are known to be capable of causing autoimmune manifestations. Most autoimmune diseases in man are dominated by Th1-type responses, and one might presume that effective immunotherapy counteracts Th1 activity, perhaps by causing a shift to a Th2 response. The mechanism of action of gold and DP is not clear, but some clues may be obtained from their effects in animal models. DP, gold salts and mercuric chloride (HgCl2) are known to induce Th2-dominated autoimmune syndromes in genetically susceptible rodent strains, and we have demonstrated recently that HgCl2 up-regulates messenger RNA (mRNA) for IL-4 in the Brown Norway (BN) rat. In the BN rat HgCl2 treatment is also associated with the development of vasculitis, and anti-myeloperoxidase (MPO) antibodies are found in the serum. The present study examined and confirmed the hypothesis that, since gold and DP induce an autoimmune syndrome similar to HgCl2 in the BN rat, they may also induce vasculitis and an up-regulation in mRNA for IL-4. Tissue injury was assessed macroscopically and histologically on day 5 and day 15 after the start of injections with gold, DP or HgCl2, serum titres of IgE and presence of anti-MPO antibodies were determined using ELISA, and a semi-quantitative assay using reverse transcription-polymerase chain reaction was used to assay the level of mRNA for IL-4 in spleen and caecum. The relative degree of tissue injury reflected the potency of induction of IgE by the three agents (HgCl2 being most potent and DP least potent). The lesions were identical histologically, supporting the premise that the vasculitis is a manifestation of the autoimmune syndrome rather than non-specific HgCl2 toxicity. Both gold and DP induced less up-regulation of mRNA for IL-4 than HgCl2. HgCl2 (but not gold or DP) induced anti-MPO antibodies. It would be interesting to examine patients treated with

  17. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

  18. Air breathing direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2002-01-01

    An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

  19. RHS6-mediated chromosomal looping and nuclear substructure binding is required for Th2 cytokine gene expression.

    PubMed

    Hwang, Soo Seok; Jang, Sung Woong; Lee, Gap Ryol

    2017-03-01

    Subset-specific gene expression is a critical feature of CD4 T cell differentiation. Th2 cells express Th2 cytokine genes including Il4, Il5, and Il13 and mediate the immune response against helminths. The expression of Th2 cytokine genes is regulated by Rad50 hypersensitive site 6 (RHS6) in the Th2 locus control region; however, the molecular mechanisms of RHS6 action at the chromatin level are poorly understood. Here, we demonstrate that RHS6 is crucial for chromosomal interactions and nuclear substructure binding of the Th2 cytokine locus. RHS6-deficient cells had a marked reduction in chromatin remodeling and in intrachromosomal interactions at the Th2 locus. Deficiency of RHS6-binding transcription factors GATA3, SATB1, and IRF4 also caused a great reduction in chromatin remodeling and long-range chromosomal interactions involving the Th2 locus. RHS6 deficiency abrogated association of the Th2 locus with the nuclear substructure and RNA polymerase II. Therefore, RHS6 serves as a crucial cis-acting hub for coordinate regulation of Th2 cytokine genes by forming chromosomal loops and binding to a nuclear substructure.

  20. Effect of ultra violet irradiation on the interplay between Th1 and Th2 lymphocytes

    PubMed Central

    Abo Elnazar, Salma Y.; Ghazy, Amany A.; Ghoneim, Hossam E.; Taha, Abdul-Rahman M.; Abouelella, Amira M.

    2015-01-01

    Although ultraviolet (UV) radiation is used to treat several types of diseases, including rickets, psoriasis, eczema, and jaundice, the prolonged exposure to its radiation may result in acute and chronic health effects particularly on the skin, eyes, and the immune system. Aim: This study was carried out to show the effect of UV on both of the lymphoproliferative response and their capacity to produce IL-12 and IL-10 in mice. Methods: Mice were exposed to whole body UVB and tested for the effect of recovery times on lymphocyte proliferation and cytokine production. In addition, direct irradiation of spleens and lymphocyte suspension was carried out. Basal and mitogens-stimulated lymphocyte proliferation was assessed by MTT assay while IL-10 and IL-12 were measured using ELISA. Results: There was a significant suppression in lymphocyte proliferation in comparison with control. IL-12 level was significantly reduced while the level of IL-10 was increased. Con A and PWM mitogens had no significant changes in IL-10 while Con A caused a highly significant increase in IL-12 at day 6 of recovery in UVB body irradiation. Conclusion: Exposure to UVB radiation could cause a state of immune suppression and shifts Th1/Th2 cell response. This effect is closely associated with the reduction of Th1 cytokines’ expression and increase in Th2 cytokines’ levels. PMID:25852558

  1. Shallow cells in directional solidification

    NASA Technical Reports Server (NTRS)

    Merchant, G. J.; Davis, S. H.

    1989-01-01

    The existing theory on two-dimensional transitions (appropriate to thin parallel-plate geometries) is presented in such a way that it is possible to identify easily conditions for the onset of shallow cells. Conditions are given under which succinonitrile-acetone mixtures should undergo supercritical bifurcation in experimentally accessible ranges. These results suggest a means for the quantitative test of the Mullins and Sekerka (1964) model and its weakly nonlinear extensions.

  2. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    PubMed

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-09-02

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis.

  3. Nestin+ cells direct inflammatory cell migration in atherosclerosis

    PubMed Central

    del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin+ cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin+ cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin+ cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin+ cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin+ stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin+ cells—but not in endothelial cells only— increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  4. Expression of Th1- Th2- and Th17-associated cytokines in laryngeal carcinoma

    PubMed Central

    Xu, Xiaoqun; Wang, Rui; Su, Qinghong; Huang, Haiyan; Zhou, Peng; Luan, Junwen; Liu, Jingsheng; Wang, Junfu; Chen, Xuemei

    2016-01-01

    T-helper (Th) 0 cell differentiation into Th1 or Th2 cells is dependent on a number of transcription factors that act at specific time points to regulate gene expression. Th17 cells, a subset of interleukin (IL)-17-producing T cells distinct from Th1 or Th2 cells, are considered to exhibit a critical function in inflammation and autoimmune diseases, as well as cancer development. In the present study, the expression of Th1-, Th2- and Th17-associated cytokines in laryngeal cancer and pericarcinoma tissues obtained from 57 laryngeal carcinoma patients was investigated. The association between Th1, Th2 and Th17 infiltration and tumor development was also evaluated. Reverse transcription-polymerase chain reaction and western blotting results revealed that the mRNA and protein expression of Th2 cytokines was lower, while the expression of Th1 and Th17 cytokines was higher in tumor tissues than in pericarcinoma tissues. Furthermore, the early stage cancer patients exhibited a higher level of interferon-γ, IL-2 and IL-17 mRNA expression than those at advanced stages. Cancer tissues exhibited higher Th17 cytokine expression than pericarcinoma tissues. By contrast, Th1 cytokine expression was increased in pericarcinoma tissues compared with cancer tissues. These results indicate that high expression of Th1- and Th17-associated cytokines in laryngeal carcinoma may contribute to suppression of cancer development and a relatively good prognosis. PMID:27588143

  5. Foxa2 Regulates Leukotrienes to Inhibit Th2-mediated Pulmonary Inflammation

    PubMed Central

    Tang, Xiaoju; Liu, Xiaojing J.; Tian, Cuijie; Su, Qiaoli; Lei, Yi; Wu, Qingbo; He, Yangyan; Whitsett, Jeffrey A.

    2013-01-01

    Foxa2 is a member of the Forkhead family of nuclear transcription factors that is highly expressed in respiratory epithelial cells of the developing and mature lung. Foxa2 is required for normal airway epithelial differentiation, and its deletion causes goblet-cell metaplasia and Th2-mediated pulmonary inflammation during postnatal development. Foxa2 expression is inhibited during aeroallergen sensitization and after stimulation with Th2 cytokines, when its loss is associated with goblet-cell metaplasia. Mechanisms by which Foxa2 controls airway epithelial differentiation and Th2 immunity are incompletely known. During the first 2 weeks after birth, the loss of Foxa2 increases the production of leukotrienes (LTs) and Th2 cytokines in the lungs of Foxa2 gene–targeted mice. Foxa2 expression inhibited 15-lipoxygenase (Alox15) and increased Alox5 transcription, each encoding key lipoxygenases associated with asthma. The inhibition of the cysteinyl LT (CysLT) signaling pathway by montelukast inhibited IL-4, IL-5, eotaxin-2, and regulated upon activation normal T cell expressed and presumably secreted expression in the developing lungs of Foxa2 gene–targeted mice. Montelukast inhibited the expression of genes regulating mucus metaplasia, including Spdef, Muc5ac, Foxa3, and Arg2. Foxa2 plays a cell-autonomous role in the respiratory epithelium, and is required for the suppression of Th2 immunity and mucus metaplasia in the developing lung in a process determined in part by its regulation of the CysLT pathway. PMID:23822876

  6. Methods of conditioning direct methanol fuel cells

    DOEpatents

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  7. Lightweight Stacks of Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram; Valdez, Thomas

    2004-01-01

    An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

  8. Th2 cytokine-induced alterations in intestinal smooth muscle function depend on alternatively activated macrophages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric nematode infection induces a strong Th2 cytokine response and is characterized by increased infiltration of various immune cells including macrophages. The role of these immune cells in host defense against enteric nematode infection, however, remains poorly defined. The present study invest...

  9. Matrix elasticity directs stem cell lineage specification

    NASA Astrophysics Data System (ADS)

    Discher, Dennis

    2010-03-01

    Adhesion of stem cells - like most cells - is not just a membrane phenomenon. Most tissue cells need to adhere to a ``solid'' for viability, and over the last decade it has become increasingly clear that the physical ``elasticity'' of that solid is literally ``felt'' by cells. Here we show that Mesenchymal Stem Cells (MSCs) specify lineage and commit to phenotypes with extreme sensitivity to the elasticity typical of tissues [1]. In serum only media, soft matrices that mimic brain appear neurogenic, stiffer matrices that mimic muscle are myogenic, and comparatively rigid matrices that mimic collagenous bone prove osteogenic. Inhibition of nonmuscle myosin II activity blocks all elasticity directed lineage specification, which indicates that the cytoskeleton pulls on matrix through adhesive attachments. Results have significant implications for `therapeutic' stem cells and have motivated development of a proteomic-scale method to identify mechano-responsive protein structures [2] as well as deeper physical studies of matrix physics [3] and growth factor pathways [4]. [4pt] [1] A. Engler, et al. Matrix elasticity directs stem cell lineage specification. Cell (2006).[0pt] [2] C.P. Johnson, et al. Forced unfolding of proteins within cells. Science (2007).[0pt] [3] A.E.X. Brown, et al. Multiscale mechanics of fibrin polymer: Gel stretching with protein unfolding and loss of water. Science (2009).[0pt] [4] D.E. Discher, et al. Growth factors, matrices, and forces combine and control stem cells. Science (2009).

  10. Diisononyl phthalate induces asthma via modulation of Th1/Th2 equilibrium.

    PubMed

    Hwang, Yun-Ho; Paik, Man-Jeong; Yee, Sung-Tae

    2017-03-12

    Diisononyl phthalate (DINP), a member of the phthalate family, is used to plasticize polyvinyl chloride (PVC). This chemical is known to enhance airway inflammation in the OVA-induced asthma model (adjuvant effects) and aggravate allergic dermatitis. Moreover, DINP enhances the production of interleukin-4 in activated CD4(+) T cells. However, the effect of DINP itself on the differentiation of naïve CD4(+) T cells into T helper cells (Th1/Th2) in vitro and allergic asthma in vivo has not yet been studied. In this study, DINP was shown to suppress the polarization of Th1 and enhance the polarization of Th2 from naïve CD4(+) T cells in vitro. Also, DINP induced allergic asthma via the production of IL-4, IL-5, IgE and IgG1 and the reduction of IFN-γ and IgG2a. Finally, we confirmed that exposure to DINP induces the infiltration of inflammatory cells and PAS positive cells and increases the expression of caspase-1 and caspase-3 in asthmatic mice. In conclusion, we suggest that DINP as an environmental pollutant or endocrine disruptor (ECD) induces asthma via the modulation of the Th1/Th2 equilibrium and production of Th2 mediated cytokines and immunoglobulin.

  11. Advances in direct oxidation methanol fuel cells

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Narayanan, S. R.; Vamos, E.; Frank, H.; Halpert, G.; Laconti, Anthony B.; Kosek, J.; Prakash, G. K. Surya; Olah, G. A.

    1993-01-01

    Fuel cells that can operate directly on fuels such as methanol are attractive for low to medium power applications in view of their low weight and volume relative to other power sources. A liquid feed direct methanol fuel cell has been developed based on a proton exchange membrane electrolyte and Pt/Ru and Pt catalyzed fuel and air/O2 electrodes, respectively. The cell has been shown to deliver significant power outputs at temperatures of 60 to 90 C. The cell voltage is near 0.5 V at 300 mA/cm(exp 2) current density and an operating temperature of 90 C. A deterrent to performance appears to be methanol crossover through the membrane to the oxygen electrode. Further improvements in performance appear possible by minimizing the methanol crossover rate.

  12. Direct formate fuel cells: A review

    NASA Astrophysics Data System (ADS)

    An, L.; Chen, R.

    2016-07-01

    Direct formate fuel cells (DFFC), which convert the chemical energy stored in formate directly into electricity, are recently attracting more attention, primarily because of the use of the carbon-neutral fuel and the low-cost electrocatalytic and membrane materials. As an emerging energy technology, the DFFC has made a rapid progress in recent years (currently, the state-of-the-art power density is 591 mW cm-2 at 60 °C). This article provides a review of past research on the development of this type of fuel cell, including the working principle, mechanisms and materials of the electrocatalytic oxidation of formate, singe-cell designs and performance, as well as innovative system designs. In addition, future perspectives with regard to the development of this fuel cell system are also highlighted.

  13. Immunomodulation Mechanism of Antidepressants: Interactions between Serotonin/Norepinephrine Balance and Th1/Th2 Balance

    PubMed Central

    Martino, Matteo; Rocchi, Giulio; Escelsior, Andrea; Fornaro, Michele

    2012-01-01

    Neurotransmitters and hormones regulate major immune functions, including the selection of T helper (Th)1 or Th2 cytokine responses, related to cell-mediated and humoral immunity, respectively. A role of imbalance and dynamic switching of Th1/Th2 system has been proposed, with relative displacement of the immune reserve in relation to complex interaction between Th1/Th2 and neuro-hormonal balance fluctuations, in the pathogenesis of various chronic human diseases, probably also including psychiatric disorders. Components of the stress system such as norepinephrine (NE) and glucocorticoids appear to mediate a Th2 shift, while serotonin (5-HT) and melatonin might mediate a Th1 shift. Some antidepressants would occur affecting these systems, acting on neurotransmitter balance (especially the 5-HT/NE balance) and expression levels of receptor subtypes, which in turn affect cytokine production and relative Th1/Th2 balance. It could be therefore hypothesized that the antidepressant-related increase in NE tone enhances the Th2 response, while the decrease in NE tone or the increase in 5-HT tone enhances the Th1 response. However, the neurotransmitter and Th1/Th2 balance modulation could be relative, aiming to restore physiological levels a previous imbalance in receptor sensitivity and cytokine production. The considerations on neuro-immunomodulation could represent an additional aid in the study of pathophysiology of psychiatric disorders and in the choice of specific antidepressants in specific clusters of symptoms, especially in comorbidity with internal pathologies. Furthermore limited data, reviewed here, have shown the effectiveness of some antidepressants as pure immunomodulators. However, these considerations are tentative and require experimental confirmation or refutation by future studies. PMID:23204981

  14. Direct Numerical Simulation of Cell Printing

    NASA Astrophysics Data System (ADS)

    Qiao, Rui; He, Ping

    2010-11-01

    Structural cell printing, i.e., printing three dimensional (3D) structures of cells held in a tissue matrix, is gaining significant attention in the biomedical community. The key idea is to use desktop printer or similar devices to print cells into 3D patterns with a resolution comparable to the size of mammalian cells, similar to that in living organs. Achieving such a resolution in vitro can lead to breakthroughs in areas such as organ transplantation and understanding of cell-cell interactions in truly 3D spaces. Although the feasibility of cell printing has been demonstrated in the recent years, the printing resolution and cell viability remain to be improved. In this work, we investigate one of the unit operations in cell printing, namely, the impact of a cell-laden droplet into a pool of highly viscous liquids using direct numerical simulations. The dynamics of droplet impact (e.g., crater formation and droplet spreading and penetration) and the evolution of cell shape and internal stress are quantified in details.

  15. Participation of MyD88 and Interleukin-33 as Innate Drivers of Th2 Immunity to Trichinella spiralis

    PubMed Central

    Scalfone, Lisa K.; Nel, Hendrik J.; Gagliardo, Lucille F.; Cameron, Jody L.; Al-Shokri, Shaikha; Leifer, Cynthia A.; Fallon, Padraic G.

    2013-01-01

    Trichinella spiralis is a highly destructive parasitic nematode that invades and destroys intestinal epithelial cells, injures many different tissues during its migratory phase, and occupies and transforms myotubes during the final phase of its life cycle. We set out to investigate the role in immunity of innate receptors for potential pathogen- or danger-associated molecular patterns (PAMPs or DAMPs). Focusing on the MyD88-dependent receptors, which include Toll-like receptors (TLRs) and interleukin-1 (IL-1) family members, we found that MyD88-deficient mice expelled worms normally, while TLR2/4-deficient mice showed accelerated worm expulsion, suggesting that MyD88 was active in signaling pathways for more than one receptor during intestinal immunity. A direct role for PAMPs in TLR activation was not supported in a transactivation assay involving a panel of murine and human TLRs. Mice deficient in the IL-1 family receptor for the DAMP, IL-33 (called ST2), displayed reduced intestinal Th2 responses and impaired mast cell activation. IL-33 was constitutively expressed in intestinal epithelial cells, where it became concentrated in nuclei within 2 days of infection. Nuclear localization was an innate response to infection that occurred in intestinal regions where worms were actively migrating. Th2 responses were also compromised in the lymph nodes draining the skeletal muscles of ST2-deficient mice, and this correlated with increased larval burdens in muscle. Our results support a mechanism in which the immune system recognizes and responds to tissue injury in a way that promotes Th2 responses. PMID:23403558

  16. Alignment of cell division axes in directed epithelial cell migration

    NASA Astrophysics Data System (ADS)

    Marel, Anna-Kristina; Podewitz, Nils; Zorn, Matthias; Oskar Rädler, Joachim; Elgeti, Jens

    2014-11-01

    Cell division is an essential dynamic event in tissue remodeling during wound healing, cancer and embryogenesis. In collective migration, tensile stresses affect cell shape and polarity, hence, the orientation of the cell division axis is expected to depend on cellular flow patterns. Here, we study the degree of orientation of cell division axes in migrating and resting epithelial cell sheets. We use microstructured channels to create a defined scenario of directed cell invasion and compare this situation to resting but proliferating cell monolayers. In experiments, we find a strong alignment of the axis due to directed flow while resting sheets show very weak global order, but local flow gradients still correlate strongly with the cell division axis. We compare experimental results with a previously published mesoscopic particle based simulation model. Most of the observed effects are reproduced by the simulations.

  17. Architecture for portable direct liquid fuel cells

    NASA Astrophysics Data System (ADS)

    Qian, Weimin; Wilkinson, David P.; Shen, Jun; Wang, Haijiang; Zhang, Jiujun

    Direct fuel cells (DFCs) are receiving increased interest for portable power applications. Cell and stack architecture is a vital technical issue for portable DFCs. The architecture of a DFC not only has to meet particular application requirements such as a compact size and easy handling, but also has to ensure desired performance, reliability and fabrication costs. In this paper, the most recent advances related to portable DFCs and their architecture are reviewed. The current status of system architecture, stack/unit cell architecture, flow-field designs and MEA morphology strategies along with analysis are surveyed. In addition, promising methods of passive fuel delivery are also presented.

  18. Improved Direct Methanol Fuel Cell Stack

    SciTech Connect

    Wilson, Mahlon S.; Ramsey, John C.

    2005-03-08

    A stack of direct methanol fuel cells exhibiting a circular footprint. A cathode and anode manifold, tie-bolt penetrations and tie-bolts are located within the circular footprint. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet and outlet cathode manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold, where the serpentine channels of the anode are orthogonal to the serpentine channels of the cathode. Located between the two plates is the fuel cell active region.

  19. Altered Th1/Th2 commitment contributes to lung senescence in CXCR3-deficient mice.

    PubMed

    Huang, Junmin; Li, Zongli; Yao, Xiujuan; Li, Yan; Reng, Xiaoxia; Li, Junfa; Wang, Wei; Gao, Jinming; Wang, Chen; Tankersley, Clarke G; Huang, Kewu

    2013-08-01

    Aging is an inevitable process associated with immune imbalance, which is characterized by a progressive functional decline in major organs, including lung. However, effects of altered Th1/Th2 commitment on lung senescence are largely unknown. To examine effects of altered Th1/Th2 balance on lung aging, we measured proportions of Th1 and Th2 cells and expression of cytokines, chemokines, collagen deposition and other relevant physiological and pathological parameters in 2- and 20-months-old (mo) CXCR3-deficient (CXCR3(-/-)) C57BL/6J mice compared with wild-type (WT) mice. There was a significant weight-loss observed in 20-mo CXCR3(-/-) mice compared with the same aged WT group. Although lung function and structure changed with age in both groups, central airway resistance (Rn), tissue elastance (H) and damping (G) were significantly lower in 20-mo CXCR3(-/-) mice than those of WT mice. In contrast, the whole lung volume (V(L)), the mean linear intercept length of alveolar (L(m)), and the total lung collagen content were significantly elevated in 20-mo CXCR3(-/-) mice. With aging, the lungs of WT mice had typical Th1-type status (increased population of Th1 cells and concentrations of cytokine IFN-γ and CXCR3 ligands) while CXCR3(-/-) mice showed Th2-type polarization (decreased proportion of Th1 cells and concentrations of CXCR3 ligands but increased level of IL-4). Our data suggest that Immunosenescence is associated with lung aging, and that altered Th1/Th2 imbalance favors Th2 predominance in CXCR3(-/-) mice, which contributes to the process of accelerated lung aging in this model.

  20. DIRECT FUEL/CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2004-05-01

    This report includes the progress in development of Direct FuelCell/Turbine{reg_sign} (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed testing of the pre-alpha DFC/T hybrid power plant. This power plant was constructed by integration of a 250kW fuel cell stack and a microturbine. The tests of the cascaded fuel cell concept for achieving high fuel utilizations were completed. The tests demonstrated that the concept results in higher power plant efficiency. Also, the preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed.

  1. Identification of a variant-specific phosphorylation of TH2A during spermiogenesis

    PubMed Central

    Hada, Masashi; Masuda, Koji; Yamaguchi, Kosuke; Shirahige, Katsuhiko; Okada, Yuki

    2017-01-01

    Tissue-specific histone variant incorporation into chromatin plays dynamic and important roles in tissue development. Testis is one such tissue, and a number of testis-specific histone variants are expressed that have unique roles. While it is expected that such variants acquire post-transcriptional modifications to be functional, identification of variant-specific histone modifications is challenging because of the high similarity of amino acid sequences between canonical and variant versions. Here we identified a novel phosphorylation on TH2A, a germ cell-specific histone H2A variant. TH2A-Thr127 is unique to the variant and phosphorylated concomitant with chromatin condensation including spermiogenesis and early embryonic mitosis. In sperm chromatin, phosphorylated TH2A-Thr127 (=pTH2A) is co-localized with H3.3 at transcriptional starting sites of the genome, and subsequently becomes absent from the paternal genome upon fertilization. Notably, pTH2A is recurrent and accumulated in the pericentromeric heterochromatin of both paternal and maternal chromosomes in the first mitosis of embryos, suggesting its unique regulation during spermiogenesis and early embryogenesis. PMID:28387373

  2. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2004-11-01

    This report includes the progress in development of Direct FuelCell/Turbine{reg_sign} (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. The operation of sub-MW hybrid Direct FuelCell/Turbine power plant test facility with a Capstone C60 microturbine was initiated in March 2003. The inclusion of the C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in previous tests using a 30kW microturbine. The design of multi-MW DFC/T hybrid systems, approaching 75% efficiency on natural gas, was initiated. A new concept was developed based on clusters of One-MW fuel cell modules as the building blocks. System analyses were performed, including systems for near-term deployment and power plants with long-term ultra high efficiency objectives. Preliminary assessment of the fuel cell cluster concept, including power plant layout for a 14MW power plant, was performed.

  3. Establishing direction during chemotaxis in eukaryotic cells.

    PubMed Central

    Rappel, Wouter-Jan; Thomas, Peter J; Levine, Herbert; Loomis, William F

    2002-01-01

    Several recent studies have demonstrated that eukaryotic cells, including amoeboid cells of Dictyostelium discoideum and neutrophils, respond to chemoattractants by translocation of PH-domain proteins to the cell membrane, where these proteins participate in the modulation of the cytoskeleton and relay of the signal. When the chemoattractant is released from a pipette, the localization is found predominantly on the proximal side of the cell. The recruitment of PH-domain proteins, particularly for Dictyostelium cells, occurs very rapidly (<2 s). Thus, the mechanism responsible for the first step in the directional sensing process of a cell must be able to establish an asymmetry on the same time scale. Here, we propose a simple mechanism in which a second messenger, generated by local activation of the membrane, diffuses through the interior of the cell, suppresses the activation of the back of the cell, and converts the temporal gradient into an initial cellular asymmetry. Numerical simulations show that such a mechanism is plausible. Available evidence suggests that the internal inhibitor may be cGMP, which accumulates within less than a second following treatment of cells with external cAMP. PMID:12202361

  4. Microbiota-Independent Ameliorative Effects of Antibiotics on Spontaneous Th2-Associated Pathology of the Small Intestine.

    PubMed

    Han, Daehee; Walsh, Matthew C; Kim, Kwang Soon; Hong, Sung-Wook; Lee, Junyoung; Yi, Jaeu; Rivas, Gloriany; Surh, Charles D; Choi, Yongwon

    2015-01-01

    We have previously generated a mouse model of spontaneous Th2-associated disease of the small intestine called TRAF6ΔDC, in which dendritic cell (DC)-intrinsic expression of the signaling mediator TRAF6 is ablated. Interestingly, broad-spectrum antibiotic treatment ameliorates TRAF6ΔDC disease, implying a role for commensal microbiota in disease development. However, the relationship between the drug effects and commensal microbiota status remains to be formally demonstrated. To directly assess this relationship, we have now generated TRAF6ΔDC bone marrow chimera mice under germ-free (GF) conditions lacking commensal microbiota, and found, unexpectedly, that Th2-associated disease is actually exacerbated in GF TRAF6ΔDC mice compared to specific pathogen-free (SPF) TRAF6ΔDC mice. At the same time, broad-spectrum antibiotic treatment of GF TRAF6ΔDC mice has an ameliorative effect similar to that observed in antibiotics-treated SPF TRAF6ΔDC mice, implying a commensal microbiota-independent effect of broad-spectrum antibiotic treatment. We further found that treatment of GF TRAF6ΔDC mice with broad-spectrum antibiotics increases Foxp3+ Treg populations in lymphoid organs and the small intestine, pointing to a possible mechanism by which treatment may directly exert an immunomodulatory effect. To investigate links between the exacerbated phenotype of the small intestines of GF TRAF6ΔDC mice and local microbiota, we performed microbiotic profiling of the luminal contents specifically within the small intestines of diseased TRAF6ΔDC mice, and, when compared to co-housed control mice, found significantly increased total bacterial content characterized by specific increases in Firmicutes Lactobacillus species. These data suggest a protective effect of Firmicutes Lactobacillus against the spontaneous Th2-related inflammation of the small intestine of the TRAF6ΔDC model, and may represent a potential mechanism for related disease phenotypes.

  5. Chrysler Pentastar direct hydrogen fuel cell program

    SciTech Connect

    Kimble, M.; Deloney, D.

    1995-08-01

    The Chrysler Pentastar Electronics, Inc. Direct Hydrogen Fueled PEM Fuel Cell Hybrid Vehicle Program (DPHV) was initiated 1 July, 1994 with the following mission, {open_quotes}Design, fabricate, and test a Direct Hydrogen Fueled Proton Exchange Membrane (PEM) Fuel Cell System including onboard hydrogen storage, an efficient lightweight fuel cell, a gas management system, peak power augmentation and a complete system controls that can be economically mass produced and comply with all safety environmental and consumer requirements for vehicle applications for the 21st century.{close_quotes} The Conceptual Design for the entire system based upon the selection of an applicable vehicle and performance requirements that are consistent with the PNGV goals will be discussed. A Hydrogen Storage system that has been selected, packaged, and partially tested in accordance with perceived Hydrogen Safety and Infrastructure requirements will be discussed in addition to our Fuel Cell approach along with design of the {open_quotes}real{close_quotes} module. The Gas Management System and the Load Leveling System have been designed and the software programs have been developed and will be discussed along with a complete fuel cell test station that has the capability to test up to a 60 kW fuel cell system.

  6. Direct fuel cell product design improvement

    SciTech Connect

    Maru, H.C.; Farooque, M.

    1996-12-31

    Significant milestones have been attained towards the technology development field testing and commercialization of direct fuel cell power plant since the 1994 Fuel Cell Seminar. Under a 5-year cooperative agreement with the Department of Energy signed in December 1994, Energy Research Corporation (ERC) has been developing the design for a MW-scale direct fuel cell power plant with input from previous technology efforts and the Santa Clara Demonstration Project. The effort encompasses product definition in consultation with the Fuel Cell Commercialization Group, potential customers, as well as extensive system design and packaging. Manufacturing process improvements, test facility construction, cell component scale up, performance and endurance improvements, stack engineering, and critical balance-of-plant development are also addressed. Major emphasis of this product design improvement project is on increased efficiency, compactness and cost reduction to establish a competitive place in the market. A 2.85 MW power plant with an efficiency of 58% and a footprint of 420 m{sup 2} has been designed. Component and subsystem testing is being conducted at various levels. Planning and preparation for verification of a full size prototype unit are in progress. This paper presents the results obtained since the last fuel cell seminar.

  7. Persistent neural activity in head direction cells

    NASA Technical Reports Server (NTRS)

    Taube, Jeffrey S.; Bassett, Joshua P.; Oman, C. M. (Principal Investigator)

    2003-01-01

    Many neurons throughout the rat limbic system discharge in relation to the animal's directional heading with respect to its environment. These so-called head direction (HD) cells exhibit characteristics of persistent neural activity. This article summarizes where HD cells are found, their major properties, and some of the important experiments that have been conducted to elucidate how this signal is generated. The number of HD and angular head velocity cells was estimated for several brain areas involved in the generation of the HD signal, including the postsubiculum, anterior dorsal thalamus, lateral mammillary nuclei and dorsal tegmental nucleus. The HD cell signal has many features in common with what is known about how neural integration is accomplished in the oculomotor system. The nature of the HD cell signal makes it an attractive candidate for using neural network models to elucidate the signal's underlying mechanisms. The conditions that any network model must satisfy in order to accurately represent how the nervous system generates this signal are highlighted and areas where key information is missing are discussed.

  8. Th2 differentiation is necessary for soft tissue fibrosis and lymphatic dysfunction resulting from lymphedema

    PubMed Central

    Avraham, Tomer; Zampell, Jamie C.; Yan, Alan; Elhadad, Sonia; Weitman, Evan S.; Rockson, Stanley G.; Bromberg, Jacqueline; Mehrara, Babak J.

    2013-01-01

    Lymphedema is a dreaded complication of cancer treatment. However, despite the fact that >5 million Americans are affected by this disorder, the development of effective treatments is limited by the fact that the pathology of lymphedema remains unknown. The purpose of these studies was to determine the role of inflammatory responses in lymphedema pathology. Using mouse models of lymphedema, as well as clinical lymphedema specimens, we show that lymphatic stasis results in a CD4+ T-cell inflammation and T-helper 2 (Th2) differentiation. Using mice deficient in T cells or CD4+ cells, we show that this inflammatory response is necessary for the pathological changes of lymphedema, including fibrosis, adipose deposition, and lymphatic dysfunction. Further, we show that inhibition of Th2 differentiation using interleukin-4 (IL-4) or IL-13 blockade prevents initiation and progression of lymphedema by decreasing tissue fibrosis and significantly improving lymphatic function, independent of lymphangiogenic growth factors. We show that CD4+ inflammation is a critical regulator of tissue fibrosis and lymphatic dysfunction in lymphedema and that inhibition of Th2 differentiation markedly improves lymphatic function independent of lymphangiogenic cytokine expression. Notably, preventing and/or reversing the development of pathological tissue changes that occur in lymphedema may be a viable treatment strategy for this disorder.—Avraham, T., Zampell, J. C., Yan, A., Elhadad, S., Weitman, E. S., Rockson, S. G., Bromberg, J., Mehrara, B. J. Th2 differentiation is necessary for soft tissue fibrosis and lymphatic dysfunction resulting from lymphedema. PMID:23193171

  9. Looking beyond the induction of Th2 responses to explain immunomodulation by helminths.

    PubMed

    Nutman, T B

    2015-06-01

    Although helminth infections are characteristically associated with Th2-mediated responses that include the production of the prototypical cytokines IL-4, IL-5 and IL-13 by CD4(+) cells, the production of IgE, peripheral blood eosinophilia and mucus production in localized sites, these responses are largely attenuated when helminth infections become less acute. This modulation of the immune response that occurs with chronic helminth infection is often induced by molecules secreted by helminth parasites, by non-Th2 regulatory CD4(+) cells, and by nonclassical B cells, macrophages and dendritic cells. This review will focus on those parasite- and host-mediated mechanisms underlying the modulated T-cell response that occurs as the default in chronic helminth infections.

  10. TH2 profile in asymptomatic Taenia solium human neurocysticercosis.

    PubMed

    Chavarría, Anahí; Roger, Beatrice; Fragoso, Gladis; Tapia, Graciela; Fleury, Agnes; Dumas, Michel; Dessein, Alain; Larralde, Carlos; Sciutto, Edda

    2003-10-01

    Neurocysticercosis (NC), a parasitic disease caused by Taenia solium, may be either asymptomatic or have mild to severe symptoms due to several factors. In this study, the immunological factors that underlie NC pleomorphism were studied. Ten of the 132 inhabitants of a rural community in Mexico (Tepez) had a computerized tomography (CT) scan compatible with calcified NC, and all were asymptomatic. Their immunological profiles were compared with those of 122 CT scan negative (non-NC) subjects from the same village. NC was associated with a TH2 response (IgG4, IL-4, IL-5, IL-13). Subjects from Tepez had higher levels of specific antibodies (IgG1, IgG2, IgG4, IgE) and specific cell proliferation than subjects from an area with low exposure (Ensenada). This suggests that non-NC subjects from Tepez had been exposed to T. solium and resisted infection in the brain. Distinct immunological profiles in equally exposed individuals differing in outcome of infection support the hypothesis of host-related factors in resistance to and pathogenesis of NC. This is the first study reporting the immunological profile associated with the asymptomatic form of NC.

  11. Direct FuelCell/Turbine Power Plant

    SciTech Connect

    Hossein Ghezel-Ayagh

    2004-11-19

    This report includes the progress in development of Direct Fuel Cell/Turbine. (DFC/T.) power plants for generation of clean power at very high efficiencies. The DFC/T power system is based on an indirectly heated gas turbine to supplement fuel cell generated power. The DFC/T power generation concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, 60% on coal gas, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, reduced carbon dioxide release to the environment, and potential cost competitiveness with existing combined cycle power plants. FCE successfully completed testing of the pre-alpha sub-MW DFC/T power plant. This power plant was constructed by integration of a 250kW fuel cell stack and a microturbine. Following these proof-of-concept tests, a stand-alone test of the microturbine verified the turbine power output expectations at an elevated (representative of the packaged unit condition) turbine inlet temperature. Preliminary design of the packaged sub-MW alpha DFC/T unit has been completed and procurement activity has been initiated. The preliminary design of a 40 MW power plant including the key equipment layout and the site plan was completed. A preliminary cost estimate for the 40 MW DFC/T plant has also been prepared. The tests of the cascaded fuel cell concept for achieving high fuel utilizations were completed. The tests demonstrated that the concept results in higher power plant efficiency. Alternate stack flow geometries for increased power output/fuel utilization capabilities are also being evaluated.

  12. Interleukin 12 inhibits antigen-induced airway hyperresponsiveness, inflammation, and Th2 cytokine expression in mice

    PubMed Central

    1995-01-01

    Allergic asthma is characterized by airway hyperresponsiveness and pulmonary eosinophilia, and may be mediated by T helper (Th) lymphocytes expressing a Th2 cytokine pattern. Interleukin (IL) 12 suppresses the expression of Th2 cytokines and their associated responses, including eosinophilia, serum immunoglobulin E, and mucosal mastocytosis. We have previously shown in a murine model that antigen- induced increases in airway hyperresponsiveness and pulmonary eosinophilia are CD4+ T cell dependent. We used this model to determine the ability of IL-12 to prevent antigen-induced increases in airway hyperresponsiveness, bronchoalveolar lavage (BAL) eosinophils, and lung Th2 cytokine expression. Sensitized A/J mice developed airway hyperresponsiveness and increased numbers of BAL eosinophils and other inflammatory cells after single or repeated intratracheal challenges with sheep red blood cell antigen. Pulmonary mRNA and protein levels of the Th2 cytokines IL-4 and IL-5 were increased after antigen challenge. Administration of IL-12 (1 microgram/d x 5 d) at the time of a single antigen challenge abolished the airway hyperresponsiveness and pulmonary eosinophilia and promoted an increase in interferon (IFN) gamma and decreases in IL-4 and IL-5 expression. The effects of IL-12 were partially dependent on IFN-gamma, because concurrent treatment with IL-12 and anti-IFN-gamma monoclonal antibody partially reversed the inhibition of airway hyperresponsiveness and eosinophilia by IL-12. Treatment of mice with IL-12 at the time of a second antigen challenge also prevented airway hyperresponsiveness and significantly reduced numbers of BAL inflammatory cells, reflecting the ability of IL-12 to inhibit responses associated with ongoing antigen-induced pulmonary inflammation. These data show that antigen-induced airway hyperresponsiveness and inflammation can be blocked by IL-12, which suppresses Th2 cytokine expression. Local administration of IL-12 may provide a novel

  13. Direct volume rendering methods for cell structures.

    PubMed

    Martišek, Dalibor; Martišek, Karel

    2012-01-01

    The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well.

  14. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2003-05-23

    In this reporting period, a milestone was achieved by commencement of testing and operation of the sub-scale hybrid direct fuel cell/turbine (DFC/T{reg_sign}) power plant. The operation was initiated subsequent to the completion of the construction of the balance-of-plant (BOP) and implementation of process and control tests of the BOP for the subscale DFC/T hybrid system. The construction efforts consisted of finishing the power plant insulation and completion of the plant instrumentation including the wiring and tubing required for process measurement and control. The preparation work also included the development of procedures for facility shake down, conditioning and load testing of the fuel cell, integration of the microturbine, and fuel cell/gas turbine load tests. At conclusion of the construction, the process and control (PAC) tests of BOP, including the microturbine, were initiated.

  15. Fucose-specific DC-SIGN signalling directs T helper cell type-2 responses via IKKε- and CYLD-dependent Bcl3 activation.

    PubMed

    Gringhuis, Sonja I; Kaptein, Tanja M; Wevers, Brigitte A; Mesman, Annelies W; Geijtenbeek, Teunis B H

    2014-05-28

    Carbohydrate-specific signalling through DC-SIGN provides dendritic cells with plasticity to tailor immunity to the nature of invading microbes. Here we demonstrate that recognition of fucose-expressing extracellular pathogens like Schistosoma mansoni and Helicobacter pylori by DC-SIGN favors T helper cell type-2 (TH2) responses via activation of atypical NF-κB family member Bcl3. Crosstalk between TLR and DC-SIGN signalling results in TLR-induced MK2-mediated phosphorylation of LSP1, associated with DC-SIGN, upon fucose binding. Subsequently, IKKε and CYLD are recruited to phosphorylated LSP1. IKKε activation is pivotal for suppression of CYLD deubiquitinase activity and subsequent nuclear translocation of ubiquitinated Bcl3. Bcl3 activation represses TLR-induced proinflammatory cytokine expression, while enhancing interleukin-10 (IL-10) and TH2-attracting chemokine expression, shifting TH differentiation from TH1 to TH2 polarization. Thus, DC-SIGN directs adaptive TH2 immunity to fucose-expressing pathogens via an IKKε-CYLD-dependent signalling pathway leading to Bcl3 activation, which might be targeted in vaccination strategies or to prevent aberrant inflammation and allergy.

  16. Selective suppression of Th2-mediated airway eosinophil infiltration by low-molecular weight CCR3 antagonists.

    PubMed

    Mori, Akio; Ogawa, Koji; Someya, Koichiro; Kunori, Yuichi; Nagakubo, Daisuke; Yoshie, Osamu; Kitamura, Fujiko; Hiroi, Takachika; Kaminuma, Osamu

    2007-08-01

    The effects of selective CC chemokine receptor (CCR)-3 antagonists on antigen-induced leukocyte accumulation in the lungs of mice adoptively transferred with in vitro-differentiated T(h)1 and T(h)2 were investigated. Inhalation of antigen by mice injected with T(h)1 and T(h)2 initiated the migration of T cells themselves into the lungs. Subsequently, neutrophils massively accumulated in T(h)1-transferred mice, whereas eosinophil infiltration was specifically induced by T(h)2. CCR3 antagonists, SB-297006 and/or SB-328437, suppressed antigen-induced accumulation of T(h)2 as well as eosinophils in the lungs, whereas they failed to affect T(h)1-mediated airway inflammation. Not only T(h)2 and eosinophil infiltration but also cellular mobilization in T(h)1-transferred mice was attenuated by an anti-CC chemokine ligand-11 antibody. CCR3 antagonists reduced chemokine production in the lungs of mice transferred with T(h)2 but not T(h)1, suggesting that down-regulation of chemokine synthesis is involved in the selective inhibition of T(h)2-mediated eosinophil infiltration by CCR3 antagonists.

  17. Expression of IL-22 in the Skin Causes Th2-Biased Immunity, Epidermal Barrier Dysfunction, and Pruritus via Stimulating Epithelial Th2 Cytokines and the GRP Pathway.

    PubMed

    Lou, Hongfei; Lu, Jingning; Choi, Eun Byul; Oh, Min Hee; Jeong, Mingeum; Barmettler, Sara; Zhu, Zhou; Zheng, Tao

    2017-04-01

    Increased expression of Th22 cytokine IL-22 is a characteristic finding in atopic dermatitis (AD). However, the specific role of IL-22 in the pathogenesis of AD in vivo has yet to be elucidated. Consistent with observations in human AD, IL-22 was significantly increased in the AD skin of mice after epicutaneous sensitization to house dust mite allergen. Utilizing a skin-specific inducible transgenic system, we show in the present study that expression of IL-22 in the skin of mice caused an AD-like phenotype characterized by chronic pruritic dermatitis associated with Th2-biased local and systemic immune responses, downregulation of epidermal differentiation complex genes, and enhanced dermatitis upon epicutaneous allergen exposure. IL-22 potently induced the expression of gastrin-releasing peptide (GRP), a neuropeptide pruritogen, in dermal immune cells and sensory afferents and in their skin-innervating sensory neurons. IL-22 also differentially upregulated the expression of GRP receptor (GRPR) on keratinocytes of AD skin. The number of GRP(+) cells in the skin correlated with the AD severity and the intensity of pruritus. IL-22 directly upregulated the expression of epithelial-derived type 2 cytokines (thymic stromal lymphopoietin and IL-33) and GRP in primary keratinocytes. Furthermore, GRP not only strongly induced thymic stromal lymphopoietin but it also increased the expression of IL-33 and GRPR synergistically with IL-22. Importantly, we found that the expression of GRP was strikingly increased in the skin of patients with AD. These results indicate that IL-22 plays important pathogenic roles in the initiation and development of AD, in part through inducing keratinocyte production of type 2 cytokines and activation of the GRP/GRPR pathway.

  18. Central role of Th2/Tc2 lymphocytes in pattern II multiple sclerosis lesions

    PubMed Central

    Planas, Raquel; Metz, Imke; Ortiz, Yaneth; Vilarrasa, Nuria; Jelčić, Ilijas; Salinas-Riester, Gabriela; Heesen, Christoph; Brück, Wolfgang; Martin, Roland; Sospedra, Mireia

    2015-01-01

    Objective Multiple sclerosis (MS) is a disease of the central nervous system with marked heterogeneity in several aspects including pathological processes. Based on infiltrating immune cells, deposition of humoral factors and loss of oligodendrocytes and/or myelin proteins, four lesion patterns have been described. Pattern II is characterized by antibody and complement deposition in addition to T-cell infiltration. MS is considered a T-cell-mediated disease, but until now the study of pathogenic T cells has encountered major challenges, most importantly the limited access of brain-infiltrating T cells. Our objective was to identify, isolate, and characterize brain-infiltrating clonally expanded T cells in pattern II MS lesions. Methods We used next-generation sequencing to identify clonally expanded T cells in demyelinating pattern II brain autopsy lesions, subsequently isolated these as T-cell clones from autologous cerebrospinal fluid and functionally characterized them. Results We identified clonally expanded CD8+ but also CD4+ T cells in demyelinating pattern II lesions and for the first time were able to isolate these as live T-cell clones. The functional characterization shows that T cells releasing Th2 cytokines and able to provide B cell help dominate the T-cell infiltrate in pattern II brain lesions. Interpretation Our data provide the first functional evidence for a putative role of Th2/Tc2 cells in pattern II MS supporting the existence of this pathogenic phenotype and questioning the protective role that is generally ascribed to Th2 cells. Our observations are important to consider for future treatments of pattern II MS patients. PMID:26401510

  19. A micro direct methanol fuel cell demonstrator

    NASA Astrophysics Data System (ADS)

    Wozniak, Konrad; Johansson, David; Bring, Martin; Sanz-Velasco, Anke; Enoksson, Peter

    2004-09-01

    The demand for compact power sources with high energy density is increasing. A direct methanol fuel cell (DMFC) is a renewable energy source which works at near room temperature, and allows for easier liquid fuel storage, which makes it a potential candidate. We report the design, fabrication and characterization of a self-driven DMFC made by micromachining techniques and macro-assembly. Several designs were created on the basis of state-of-the-art DMFCs. A simplified mathematical model was used mainly to design the flow channels and verify the polarization curves, which reveal the output power of a cell. Silicon was used as a substrate for the fabrication of electrodes, and the membrane electrode assembly was provided by Ion Power, Inc. A 0.25 cm2 cell showed a performance of 0.29 mW cm-2 and an open circuit voltage of 0.7 V. Ten microliters of 6 M methanol solution is sufficient to operate the cell for more than 1 h.

  20. Epidermal expression of I-TAC (Cxcl11) instructs adaptive Th2-type immunity.

    PubMed

    Roebrock, Kirsten; Sunderkötter, Cord; Münck, Niels-Arne; Wolf, Marc; Nippe, Nadine; Barczyk, Katarzyna; Varga, Georg; Vogl, Thomas; Roth, Johannes; Ehrchen, Jan

    2014-04-01

    To decipher early promoters of the local microenvironment for Th2-type immunity, we wanted to identify gene patterns that were induced by Leishmania major in the infected skin of susceptible, Th2-prone BALB/c, but not of resistant, Th1-prone C57BL/6 mice. We found a marked up-regulation of the chemokine I-TAC (Cxcl11) during the first 2 d of infection in the epidermis of susceptible but not of resistant mice. Accordingly, local injection of I-TAC (2×1 μg) in resistant mice on the first day of infection resulted in a Th2-driven, sustained deterioration of disease and dramatically enhanced parasite levels. On the cellular level, I-TAC decreased IL-12 production by dendritic cells (DCs) in skin-draining lymph nodes and by DCs in vitro. Thus, we demonstrate for the first time that epidermis-derived I-TAC triggers a sustained Th2-response that determines the outcome of a complex immunological process.

  1. Nanoparticle clearance is governed by Th1/Th2 immunity and strain background

    PubMed Central

    Jones, Stephen W.; Roberts, Reid A.; Robbins, Gregory R.; Perry, Jillian L.; Kai, Marc P.; Chen, Kai; Bo, Tao; Napier, Mary E.; Ting, Jenny P.Y.; DeSimone, Joseph M.; Bear, James E.

    2013-01-01

    Extended circulation of nanoparticles in blood is essential for most clinical applications. Nanoparticles are rapidly cleared by cells of the mononuclear phagocyte system (MPS). Approaches such as grafting polyethylene glycol onto particles (PEGylation) extend circulation times; however, these particles are still cleared, and the processes involved in this clearance remain poorly understood. Here, we present an intravital microscopy–based assay for the quantification of nanoparticle clearance, allowing us to determine the effect of mouse strain and immune system function on particle clearance. We demonstrate that mouse strains that are prone to Th1 immune responses clear nanoparticles at a slower rate than Th2-prone mice. Using depletion strategies, we show that both granulocytes and macrophages participate in the enhanced clearance observed in Th2-prone mice. Macrophages isolated from Th1 strains took up fewer particles in vitro than macrophages from Th2 strains. Treating macrophages from Th1 strains with cytokines to differentiate them into M2 macrophages increased the amount of particle uptake. Conversely, treating macrophages from Th2 strains with cytokines to differentiate them into M1 macrophages decreased their particle uptake. Moreover, these results were confirmed in human monocyte–derived macrophages, suggesting that global immune regulation has a significant impact on nanoparticle clearance in humans. PMID:23778144

  2. Direct FuelCell/Turbine Power Plant

    SciTech Connect

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply to the

  3. Interleukin-19 contributes as a protective factor in experimental Th2-mediated colitis.

    PubMed

    Fujimoto, Yasuyuki; Azuma, Yasu-Taka; Matsuo, Yukiko; Kuwamura, Mitsuru; Kuramoto, Nobuyuki; Miki, Mariko; Azuma, Naoki; Teramoto, Midori; Nishiyama, Kazuhiro; Izawa, Takeshi; Nakajima, Hidemitsu; Takeuchi, Tadayoshi

    2017-03-01

    Inflammatory bowel disease results from chronic dysregulation of the mucosal immune system and aberrant activation of both the innate and adaptive immune responses. IL-19 is a member of the IL-10 family, and IL-10 plays an important role in inflammatory bowel disease. We have previously shown that IL-19 knockout mice are more susceptible to innate-mediated colitis. Next, we ask whether IL-19 contributes to T cells-mediated colitis. Here, we investigated the role of IL-19 in a mouse model of Th2 cell-mediated colitis. Inflammatory responses in IL-19-deficient mice were assessed using a Th2-mediated colitis induced by oxazolone. The colitis was evaluated by analyzing the body weight loss and histology of the colon. Lymph node cells were cultured in vitro to determine cytokine production. IL-19 knockout mice exacerbated oxazolone-induced colitis by stimulating the transport of inflammatory cells into the colon, and by increasing IgE production and the number of circulating eosinophil. The exacerbation of oxazolone-induced colonic inflammation following IL-19 knockout mice was accompanied by an increased production of IL-4 and IL-9, but no changes in the expression of IL-5 and IL-13 in lymph node cells. IL-19 plays an anti-inflammatory role in the Th2-mediated colitis model, suggesting that IL-19 may represent a potential therapeutic target for reducing colonic inflammation.

  4. Selectivity of Direct Methanol Fuel Cell Membranes.

    PubMed

    Aricò, Antonino S; Sebastian, David; Schuster, Michael; Bauer, Bernd; D'Urso, Claudia; Lufrano, Francesco; Baglio, Vincenzo

    2015-11-24

    Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion(®) were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate-PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA) was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC). The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA) was higher than the benchmark Nafion(®) 115-based MEA (77 mW·cm(-2) vs. 64 mW·cm(-2)). This result was due to a lower methanol crossover (47 mA·cm(-2) equivalent current density for s-PEEK vs. 120 mA·cm(-2) for Nafion(®) 115 at 60 °C as recorded at OCV with 2 M methanol) and a suitable area specific resistance (0.15 Ohm cm² for s-PEEK vs. 0.22 Ohm cm² for Nafion(®) 115).

  5. Selectivity of Direct Methanol Fuel Cell Membranes

    PubMed Central

    Aricò, Antonino S.; Sebastian, David; Schuster, Michael; Bauer, Bernd; D’Urso, Claudia; Lufrano, Francesco; Baglio, Vincenzo

    2015-01-01

    Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion® were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate–PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA) was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC). The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA) was higher than the benchmark Nafion® 115-based MEA (77 mW·cm−2 vs. 64 mW·cm−2). This result was due to a lower methanol crossover (47 mA·cm−2 equivalent current density for s-PEEK vs. 120 mA·cm−2 for Nafion® 115 at 60 °C as recorded at OCV with 2 M methanol) and a suitable area specific resistance (0.15 Ohm cm2 for s-PEEK vs. 0.22 Ohm cm2 for Nafion® 115). PMID:26610582

  6. Skin exposure promotes a Th2-dependent sensitization to peanut allergens.

    PubMed

    Tordesillas, Leticia; Goswami, Ritobrata; Benedé, Sara; Grishina, Galina; Dunkin, David; Järvinen, Kirsi M; Maleki, Soheila J; Sampson, Hugh A; Berin, M Cecilia

    2014-11-01

    Sensitization to foods often occurs in infancy, without a known prior oral exposure, suggesting that alternative exposure routes contribute to food allergy. Here, we tested the hypothesis that peanut proteins activate innate immune pathways in the skin that promote sensitization. We exposed mice to peanut protein extract on undamaged areas of skin and observed that repeated topical exposure to peanut allergens led to sensitization and anaphylaxis upon rechallenge. In mice, this epicutaneous peanut exposure induced sensitization to the peanut components Ara h 1 and Ara h 2, which is also observed in human peanut allergy. Both crude peanut extract and Ara h 2 alone served as adjuvants, as both induced a bystander sensitization that was similar to that induced by the atopic dermatitis-associated staphylococcal enterotoxin B. In cultured human keratinocytes and in murine skin, peanut extract directly induced cytokine expression. Moreover, topical peanut extract application induced an alteration dependent on the IL-33 receptor ST2 in skin-draining DCs, resulting in Th2 cytokine production from T cells. Together, our data support the hypothesis that peanuts are allergenic due to inherent adjuvant activity and suggest that skin exposure to food allergens contributes to sensitization to foods in early life.

  7. Arabidopsis TH2 Encodes the Orphan Enzyme Thiamin Monophosphate Phosphatase[OPEN

    PubMed Central

    Niehaus, Thomas D.; Hasnain, Ghulam; Gidda, Satinder K.; Nguyen, Thuy N.D.; Anderson, Erin M.; Brown, Greg; Yakunin, Alexander F.; de Crécy-Lagard, Valérie; Gregory, Jesse F.

    2016-01-01

    To synthesize the cofactor thiamin diphosphate (ThDP), plants must first hydrolyze thiamin monophosphate (ThMP) to thiamin, but dedicated enzymes for this hydrolysis step were unknown and widely doubted to exist. The classical thiamin-requiring th2-1 mutation in Arabidopsis thaliana was shown to reduce ThDP levels by half and to increase ThMP levels 5-fold, implying that the THIAMIN REQUIRING2 (TH2) gene product could be a dedicated ThMP phosphatase. Genomic and transcriptomic data indicated that TH2 corresponds to At5g32470, encoding a HAD (haloacid dehalogenase) family phosphatase fused to a TenA (thiamin salvage) family protein. Like the th2-1 mutant, an insertional mutant of At5g32470 accumulated ThMP, and the thiamin requirement of the th2-1 mutant was complemented by wild-type At5g32470. Complementation tests in Escherichia coli and enzyme assays with recombinant proteins confirmed that At5g32470 and its maize (Zea mays) orthologs GRMZM2G148896 and GRMZM2G078283 are ThMP-selective phosphatases whose activity resides in the HAD domain and that the At5g32470 TenA domain has the expected thiamin salvage activity. In vitro and in vivo experiments showed that alternative translation start sites direct the At5g32470 protein to the cytosol and potentially also to mitochondria. Our findings establish that plants have a dedicated ThMP phosphatase and indicate that modest (50%) ThDP depletion can produce severe deficiency symptoms. PMID:27677881

  8. Differential Activation of Airway Eosinophils Induces IL-13 Mediated Allergic Th2 Pulmonary Responses in Mice

    PubMed Central

    Jacobsen, EA; Doyle, AD; Colbert, DC; Zellner, KR; Protheroe, CA; LeSuer, WE; Lee, NA.; Lee, JJ

    2015-01-01

    Background Eosinophils are hallmark cells of allergic Th2 respiratory inflammation. However, the relative importance of eosinophil activation and the induction of effector functions such as the expression of IL-13 to allergic Th2 pulmonary disease remain to be defined. Methods Wild type or cytokine deficient (IL-13−/− or IL-4−/−) eosinophils treated with cytokines (GM-CSF, IL-4, IL-33) were adoptively transferred into eosinophil-deficient recipient mice subjected to allergen provocation using established models of respiratory inflammation. Allergen-induced pulmonary changes were assessed. Results In contrast to the transfer of untreated blood eosinophils to the lungs of recipient eosinophildeficient mice, which induced no immune/inflammatory changes either in the lung or lung draining lymph nodes (LDLNs), pretreatment of blood eosinophils with GM-CSF prior to transfer elicited trafficking of these eosinophils to LDLNs. In turn, these LDLN eosinophils elicited the accumulation of dendritic cells and CD4+ T cells to these same LDLNs without inducing pulmonary inflammation. However, exposure of eosinophils to GM-CSF, IL-4 and IL-33 prior to transfer induced not only immune events in the LDLN, but also allergen-mediated increases in airway Th2 cytokine/chemokine levels, the subsequent accumulation of CD4+ T cells as well as alternatively activated (M2) macrophages, and the induction of pulmonary histopathologies. Significantly, this allergic respiratory inflammation was dependent on eosinophil-derived IL-13 whereas IL-4 expression by eosinophils had no significant role. Conclusion The data demonstrate the differential activation of eosinophils as a function of cytokine exposure and suggest that eosinophil-specific IL-13 expression by activated cells is a necessary component of the subsequent allergic Th2 pulmonary pathologies. PMID:26009788

  9. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2003-05-22

    Project activities were focused on the design and construction the sub-scale hybrid Direct Fuel Cell/turbine (DFC/T{reg_sign}) power plant and modification of a Capstone Simple Cycle Model 330 microturbine. The power plant design work included preparation of system flow sheet and performing computer simulations based on conservation of mass and energy. The results of the simulation analyses were utilized to prepare data sheets and specifications for balance-of-plant equipment. Process flow diagram (PFD) and piping and instrumentation diagrams (P&ID) were also completed. The steady state simulation results were used to develop design information for modifying the control functions, and for sizing the heat exchangers required for recuperating the waste heat from the power plant. Line and valve sizes for the interconnecting pipes between the microturbine and the heat recuperators were also identified.

  10. Differential chemokine expression following respiratory virus infection reflects Th1- or Th2-biased immunopathology.

    PubMed

    Culley, Fiona J; Pennycook, Alasdair M J; Tregoning, John S; Hussell, Tracy; Openshaw, Peter J M

    2006-05-01

    Respiratory syncytial virus (RSV) is a major viral pathogen of infants that also reinfects adults. During RSV infection, inflammatory host cell recruitment to the lung plays a central role in determining disease outcome. Chemokines mediate cell recruitment to sites of inflammation and are influenced by, and influence, the production of cytokines. We therefore compared chemokine production in a mouse model of immunopathogenic RSV infection in which either Th1 or Th2 immunopathology is induced by prior sensitization to individual RSV proteins. Chemokine expression profiles were profoundly affected by the nature of the pulmonary immunopathology: "Th2" immunopathology in BALB/c mice was associated with increased and prolonged expression of CCL2 (MCP-1), CXCL10 (IP-10), and CCL11 (eotaxin) starting within 24 h of challenge. C57BL/6 mice with "Th2" pathology (enabled by a deficiency of CD8+ cells) also showed increased CCL2 production. No differences in chemokine receptor expression were detected. Chemokine blockers may therefore be of use for children with bronchiolitis.

  11. Basophil-associated OX40 Ligand Participates in the Initiation of Th2 Responses during Airway Inflammation*

    PubMed Central

    Di, Caixia; Lin, Xiaoliang; Zhang, Yanjie; Zhong, Wenwei; Yuan, Yufan; Zhou, Tong; Liu, Junling; Xia, Zhenwei

    2015-01-01

    Asthma is characterized by increased airway submucosal infiltration of T helper (Th) cells and myeloid cells that co-conspire to sustain a chronic inflammation. While recent studies have demonstrated that the myeloid basophils promote Th2 cells in response to various types of allergens, the underlying mechanisms are poorly understood. Here, we found for the first time that in a mouse model of allergic asthma basophils highly expressed OX40 ligand (OX40L) after activation. Interestingly, blockade of OX40-OX40L interaction suppressed basophils-primed Th2 cell differentiation in vitro and ameliorated ovalbumin (OVA)-induced allergic eosinophilic inflammation mediated by Th2 activation. In accordance, the adoptive transfer of basophils derived from mediastinal lymph nodes (MLN) of OVA-immunized mice triggered a robust Th2 response and eosinophilic inflammation in wild-type mice but largely muted in OX40−/− mice and mice receiving OX40L-blocked basophils. Taken together, our results reveal a critical role of OX40L presented by the activated basophils to initiate Th2 responses in an allergic asthma model, implicating OX40-OX40L signaling as a potential therapeutic target in the treatment of allergic airway inflammation. PMID:25839234

  12. Treatment of mice with fenbendazole attenuates allergic airways inflammation and Th2 cytokine production in a model of asthma.

    PubMed

    Cai, Yeping; Zhou, Jiansheng; Webb, Dianne C

    2009-01-01

    Mouse models have provided a significant insight into the role of T-helper (Th) 2 cytokines such as IL-5 and IL-13 in regulating eosinophilia and other key features of asthma. However, the validity of these models can be compromised by inadvertent infection of experimental mouse colonies with pathogens such as oxyurid parasites (pinworms). While the benzimidazole derivative, fenbendazole (FBZ), is commonly used to treat such outbreaks, the effects of FBZ on mouse models of Th2 disease are largely unknown. In this investigation, we show that mice fed FBZ-supplemented food during the in utero and post-weaning period developed attenuated lung eosinophilia, antigen-specific IgG1 and Th2 cytokine responses in a model of asthma. Treatment of the mediastinal lymph node cells from allergic mice with FBZ in vitro attenuated cell proliferation, IL-5 and IL-13 production and expression of the early lymphocyte activation marker, CD69 on CD4(+) T cells and CD19(+) B cells. In addition, eosinophilia and Th2 responses remained attenuated after a 4-week withholding period in allergic mice treated preweaning with FBZ. Thus, FBZ modulates the amplitude of Th2 responses both in vivo and in vitro.

  13. Transcriptionally Regulated Cell Adhesion Network Dictates Distal Tip Cell Directionality

    PubMed Central

    Wong, Ming-Ching; Kennedy, William P.; Schwarzbauer, Jean E.

    2015-01-01

    Background The mechanisms that govern directional changes in cell migration are poorly understood. The migratory paths of two distal tip cells (DTC) determine the U-shape of the C. elegans hermaphroditic gonad. The morphogenesis of this organ provides a model system to identify genes necessary for the DTCs to execute two stereotyped turns. Results Using candidate genes for RNAi knockdown in a DTC-specific strain, we identified two transcriptional regulators required for DTC turning: cbp-1, the CBP/p300 transcriptional coactivator homologue, and let-607, a CREBH transcription factor homologue. Further screening of potential target genes uncovered a network of integrin adhesion-related genes that have roles in turning and are dependent on cbp-1 and let-607 for expression. These genes include src-1/Src kinase, tln-1/talin, pat-2/α integrin and nmy-2, a nonmuscle myosin heavy chain. Conclusions Transcriptional regulation by means of cbp-1 and let-607 is crucial for determining directional changes during DTC migration. These regulators coordinate a gene network that is necessary for integrin-mediated adhesion. Overall, these results suggest that directional changes in cell migration rely on the precise gene regulation of adhesion. PMID:24811939

  14. Directional Excitatory Input to Direction-Selective Ganglion Cells in the Rabbit Retina.

    PubMed

    Percival, Kumiko A; Venkataramani, Sowmya; Smith, Robert G; Rowland Taylor, W

    2017-03-14

    Directional responses in retinal ganglion cells are generated in large part by direction-selective release of GABA from starburst amacrine cells onto direction-selective ganglion cells (DSGCs). The excitatory inputs to DSGCs are also widely reported to be direction-selective, however, recent evidence suggests that glutamate release from bipolar cells is not directional, and directional excitation seen in patch-clamp analyses may be an artifact resulting from incomplete voltage control. Here we test this voltage-clamp-artifact hypothesis in recordings from 62 On-Off DSGCs in the rabbit retina. The strength of the directional excitatory signal varies considerably across the sample of cells, but is not correlated with the strength of directional inhibition, as required for a voltage-clamp artifact. These results implicate additional mechanisms in generating directional excitatory inputs to DSGCs. This article is protected by copyright. All rights reserved.

  15. Direct contact between dendritic cells and bronchial epithelial cells inhibits T cell recall responses towards mite and pollen allergen extracts in vitro.

    PubMed

    Papazian, D; Wagtmann, V R; Hansen, S; Würtzen, P A

    2015-08-01

    Airway epithelial cells (AECs) form a polarized barrier along the respiratory tract. They are the first point of contact with airborne antigens and are able to instruct resident immune cells to mount appropriate immune responses by either soluble or contact-dependent mechanisms. We hypothesize that a healthy, polarized epithelial cell layer inhibits inflammatory responses towards allergens to uphold homeostasis. Using an in-vitro co-culture model of the airway epithelium, where a polarized cell layer of bronchial epithelial cells can interact with dendritic cells (DCs), we have investigated recall T cell responses in allergic patients sensitized to house dust mite, grass and birch pollen. Using allergen extract-loaded DCs to stimulate autologous allergen-specific T cell lines, we show that AEC-imprinted DCs inhibit T cell proliferation significantly of Bet v 1-specific T cell lines as well as decrease interleukin (IL)-5 and IL-13 production, whereas inhibition of Phl p 5-specific T cells varied between different donors. Stimulating autologous CD4(+) T cells from allergic patients with AEC-imprinted DCs also inhibited proliferation significantly and decreased production of both T helper type 1 (Th1) and Th2 cytokines upon rechallenge. The inhibitory effects of AECs' contact with DCs were absent when allergen extract-loaded DCs had been exposed only to AECs supernatants, but present after direct contact with AECs. We conclude that direct contact between DCs and AECs inhibits T cell recall responses towards birch, grass and house dust mite allergens in vitro, suggesting that AECs-DC contact in vivo constitute a key element in mucosal homeostasis in relation to allergic sensitisation.

  16. Synthesis and Characterization of Th2N2(NH) Isomorphous to Th2N3

    SciTech Connect

    Silva, G W Chinthaka M; Yeamans, Charles B.; Hunn, John D; Sattelberger, Alfred P; Czerwinski, Ken R.; Weck, Dr. Phil F

    2012-01-01

    Using a new, low-temperature, fluoride-based process, thorium nitride imide of the chemical formula Th{sub 2}N{sub 2}(NH) was synthesized from thorium dioxide via an ammonium thorium fluoride intermediate. The resulting product phase was characterized by powder X-ray diffraction (XRD) analysis and was found to be crystallographically similar to Th{sub 2}N{sub 3}. Its unit cell was hexagonal with a space group of P3m{bar 1} and lattice parameters of a = b = 3.886(1) and c = 6.185(2) {angstrom}. The presence of -NH in the nitride phase was verified by Fourier transform infrared spectroscopy (FTIR). Total energy calculations performed using all-electron scalar relativistic density functional theory (DFT) showed that the hydrogen atom in the Th{sub 2}N{sub 2}(NH) prefers to bond with nitrogen atoms occupying 1a Wyckoff positions of the unit cell. Lattice fringe disruptions observed in nanoparticle areas of the nitride species by high-resolution transmission electron microscopic (HRTEM) images also displayed some evidence for the presence of -NH group. As ThO{sub 2} was identified as an impurity, possible reaction mechanisms involving its formation are discussed.

  17. Early immunological response to German cockroach frass exposure induces a Th2/Th17 environment.

    PubMed

    Page, Kristen; Zhou, Ping; Ledford, John R; Day, Scottie B; Lutfi, Riad; Dienger, Krista; Lewkowich, Ian P

    2011-01-01

    Cockroach exposure is a major risk factor for the development of asthma; however, the early immune events induced by cockroach leading to the Th2 response are not fully understood. Exposure of naïve mice to German cockroach (GC) feces (frass) was sufficient to induce dendritic cell (DC) recruiting and activating chemokines C-C motif ligand 20, granulocyte macrophage colony-stimulating factor, granulocyte colony-stimulating factor and macrophage inflammatory protein-1α into the airways. This corresponded with an increase in myeloid DCs (mDCs) in the airways as well as increased expression of CD80 and CD86 on the mDCs. Plasmacytoid DCs in the lung were unchanged. Levels of IL-5, IL-17A and IL-6 cytokines in whole lung cultures were significantly increased 18 h following GC frass exposure demonstrating the early development of a mixed Th2/Th17 response. In addition, GC frass stimulated the production of IL-23, IL-6 and IL-12p70 from bone marrow-derived mDCs. Adoptive transfer of GC frass-pulsed mDCs induced airway reactivity, airway inflammation as well as eosinophilia and induced a strong Th2/Th17 response in the lung. MyD88-deficient bone marrow-derived mDCs did not respond to GC frass treatment, suggesting a functional Toll-like receptor pathway was important to induce the Th2/Th17 response. Together, our data show that GC frass activated the innate immune response to augment DC recruitment and activation of mDCs which promoted robust T cell-skewing cytokines and ultimately drive the development of airway inflammation.

  18. Directional sensitivity of hair cell afferents in the Octopus statocyst.

    PubMed

    Budelmann, B U; Williamson, R

    1994-02-01

    Changes in threshold sensitivity of hair cell afferents of the macula and crista of the Octopus statocyst were analyzed when the hair cells were stimulated with sinusoidal water movements from different directions. The experiments indicate that cephalopod statocyst hair cells are directionally sensitive in a way that is similar to the responses of the hair cells of the vertebrate vestibular and lateral line systems, with the amplitude of the response changing according to the cosine of the angle by which the direction of the stimulus (the deflection of the ciliary bundle) deviates from the direction of the hair cell's morphological polarization.

  19. Immunization of proteins from Toxascaris leonina adult worm inhibits allergic specific Th2 response.

    PubMed

    Lee, Keun Hee; Park, Hye Kyung; Jeong, Hae Jin; Park, Sang Kyun; Lee, Sun Joo; Choi, Sun Hee; Cho, Min Kyoung; Ock, Mee Sun; Hong, Yeon-Chul; Yu, Hak Sun

    2008-10-01

    Recently, the influence of parasitic infections on the incidence of allergic diseases has become the focus of increased attention. In order to ascertain whether parasite-derived proteins could inhibit the allergic specific Th2 response, we applied excretory-secretory protein (Tl-ES) or total protein (Tl-TP) of the adult worm Toxascaris leonina to asthma model mice prior to or simultaneously with OVA challenge, after which we assessed the OVA-specific Th2 responses. The group subjected to immunization with Tl-ES and Tl-TP (immunized group) evidenced a thinning of the bronchial epithelial and muscle layer, a disruption and shedding of epithelial cells, a reduction in the number of goblet cells, and a reduction in mucus production as compared to the group treated with Tl-ES coupled with OVA challenge (challenge with OVA groups) and the OVA-induced asthma group. The administration of Tl-ES and Tl-TP, regardless of injection time, was shown to inhibit the recruitment of inflammatory cells into the airway, and in particular, macrophages, neutrophils, and lymphocytes were significantly reduced as the result of the parasite proteins. However, the total number of eosinophils was slightly reduced as the result of the administration of parasite proteins. Sensitization and OVA challenge was shown to accelerate the secretion of Th2 cytokines (IL-4 and IL-5) within the lung, but in the immunized groups, those levels were lower. The administration of Tl-TP and OVA challenge group also evidenced a significant reduction in IL-4 levels as compared to the OVA-challenged group. The concentrations of Th2 cytokines in the Tl-ES and OVA challenge group were more similar to those observed in the OVA-challenged group. The concentration of IL-10 and TGF-beta in the lung was decreased substantially in the OVA-only challenge group, but the Tl-TP immunized group exhibited significantly induced IL-10 cytokine. OVA-specific IgG2a, IgG1, and IgE levels in the immunized groups were significantly

  20. Th-1, Th-2 Cytokines Profile among Madurella mycetomatis Eumycetoma Patients

    PubMed Central

    Nasr, Amre; Abushouk, Amir; Hamza, Anhar; Siddig, Emmanuel; Fahal, Ahmed H.

    2016-01-01

    Eumycetoma is a progressive and destructive chronic granulomatous subcutaneous inflammatory disease caused by certain fungi, the most common being Madurella mycetomatis. The host defence mechanisms against fungi usually range from an early non-specific immune response to activation and induction of specific adaptive immune responses by the production of Th-1 and Th-2 cytokines. The aim of this study is to determine the levels of Th-1 and Th-2 cytokines in patients infected with Madurella mycetomatis, and the association between their levels and disease prognosis. This is a descriptive cross-sectional study conducted at the Mycetoma Research Centre, University of Khartoum, Sudan, where 70 patients with confirmed M. mycetomatis eumycetoma were enrolled; 35 with, and 35 without surgical excision. 70 healthy individuals from mycetoma endemic areas were selected as controls. The levels of serum cytokines were determined by cytometric bead array technique. Significantly higher levels of the Th-1 cytokines (IFN-γ, TNF-α, IL-1β and IL-2) were recorded in patients treated with surgical excision, compared to those treated without surgical excision. In contrast, the Th-2 cytokines (IL-4, IL-5, IL-6 and IL-10) were significantly lower in patients treated with surgical excision compared to those treated without surgical excision. In conclusion, the results of this study suggest that cell-mediated immunity can have a role to play in the pathogenesis of eumycetoma. PMID:27434108

  1. FOXP3+ Tregs require WASP to restrain Th2-mediated food allergy

    PubMed Central

    Lexmond, Willem S.; Goettel, Jeremy A.; Lyons, Jonathan J.; Jacobse, Justin; Deken, Marion M.; Lawrence, Monica G.; DiMaggio, Thomas H.; Kotlarz, Daniel; Garabedian, Elizabeth; Sackstein, Paul; Nelson, Celeste C.; Jones, Nina; Stone, Kelly D.; Rings, Edmond H.H.M.; Thrasher, Adrian J.; Milner, Joshua D.; Snapper, Scott B.; Fiebiger, Edda

    2016-01-01

    In addition to the infectious consequences of immunodeficiency, patients with Wiskott-Aldrich syndrome (WAS) often suffer from poorly understood exaggerated immune responses that result in autoimmunity and elevated levels of serum IgE. Here, we have shown that WAS patients and mice deficient in WAS protein (WASP) frequently develop IgE-mediated reactions to common food allergens. WASP-deficient animals displayed an adjuvant-free IgE-sensitization to chow antigens that was most pronounced for wheat and soy and occurred under specific pathogen–free as well as germ-free housing conditions. Conditional deletion of Was in FOXP3+ Tregs resulted in more severe Th2-type intestinal inflammation than that observed in mice with global WASP deficiency, indicating that allergic responses to food allergens are dependent upon loss of WASP expression in this immune compartment. While WASP-deficient Tregs efficiently contained Th1- and Th17-type effector differentiation in vivo, they failed to restrain Th2 effector responses that drive allergic intestinal inflammation. Loss of WASP was phenotypically associated with increased GATA3 expression in effector memory FOXP3+ Tregs, but not in naive-like FOXP3+ Tregs, an effect that occurred independently of increased IL-4 signaling. Our results reveal a Treg-specific role for WASP that is required for prevention of Th2 effector cell differentiation and allergic sensitization to dietary antigens. PMID:27643438

  2. Laser-based direct-write techniques for cell printing.

    PubMed

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2010-09-01

    Fabrication of cellular constructs with spatial control of cell location (+/-5 microm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing.

  3. Laser-based direct-write techniques for cell printing

    PubMed Central

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2016-01-01

    Fabrication of cellular constructs with spatial control of cell location (±5 μm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. PMID:20814088

  4. Inflammatory dendritic cells—not basophils—are necessary and sufficient for induction of Th2 immunity to inhaled house dust mite allergen

    PubMed Central

    Plantinga, Maud; Deswarte, Kim; Pouliot, Philippe; Willart, Monique A.M.; Kool, Mirjam; Muskens, Femke

    2010-01-01

    It is unclear how Th2 immunity is induced in response to allergens like house dust mite (HDM). Here, we show that HDM inhalation leads to the TLR4/MyD88-dependent recruitment of IL-4 competent basophils and eosinophils, and of inflammatory DCs to the draining mediastinal nodes. Depletion of basophils only partially reduced Th2 immunity, and depletion of eosinophils had no effect on the Th2 response. Basophils did not take up inhaled antigen, present it to T cells, or express antigen presentation machinery, whereas a population of FceRI+ DCs readily did. Inflammatory DCs were necessary and sufficient for induction of Th2 immunity and features of asthma, whereas basophils were not required. We favor a model whereby DCs initiate and basophils amplify Th2 immunity to HDM allergen. PMID:20819925

  5. Direct reprogramming and biomaterials for controlling cell fate.

    PubMed

    Kim, Eunsol; Tae, Giyoong

    2016-01-01

    Direct reprogramming which changes the fate of matured cell is a very useful technique with a great interest recently. This approach can eliminate the drawbacks of direct usage of stem cells and allow the patient specific treatment in regenerative medicine. Overexpression of diverse factors such as general reprogramming factors or lineage specific transcription factors can change the fate of already differentiated cells. On the other hand, biomaterials can provide physical and topographical cues or biochemical cues on cells, which can dictate or significantly affect the differentiation of stem cells. The role of biomaterials on direct reprogramming has not been elucidated much, but will be potentially significant to improve the efficiency or specificity of direct reprogramming. In this review, the strategies for general direct reprogramming and biomaterials-guided stem cell differentiation are summarized with the addition of the up-to-date progress on biomaterials for direct reprogramming.

  6. TLR2 signaling and Th2 responses drive Tannerella forsythia-induced periodontal bone loss.

    PubMed

    Myneni, Srinivas R; Settem, Rajendra P; Connell, Terry D; Keegan, Achsah D; Gaffen, Sarah L; Sharma, Ashu

    2011-07-01

    Periodontal disease (PD) is a chronic inflammation of the tooth-supporting soft tissue and alveolar bone due to infection by a select group of gram-negative microbes, which leads to tooth loss if untreated. Because mice deficient in CD4(+) cells are resistant to infection-induced alveolar bone loss, Th cells have been implicated in bone-destructive processes during PD. However, the extent to which different Th cell subtypes play roles in pathogenesis or host protection remains to be defined and is likely to vary depending on the dominant microorganism involved. By far, Porphyromonas gingivalis is the best-studied periodontal microbe in PD. Although the gram-negative anaerobe Tannerella forsythia is also a vital contributor to periodontal bone loss, almost nothing is known about immune responses to this organism. Previous studies from our laboratory revealed that T. forsythia induces periodontal bone loss in mice and that this bone loss depends on the bacterially expressed BspA protein. In this study, we showed that T. forsythia activates murine APCs primarily through TLR2-dependent signaling via BspA. Furthermore, T. forsythia infection causes a pronounced Th2 bias, evidenced by T cell expression of IL-5, but not IFN-γ or IL-17, in draining lymph nodes. Consistently, deficiencies in TLR2 or STAT6 result in resistance to T. forsythia-induced alveolar bone loss. Thus, TLR2 signaling and Th2 cells play pathogenic roles in T. forsythia-induced alveolar bone destruction.

  7. Direct methanol feed fuel cell and system

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2009-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous. The fuel cell system also comprises a fuel supplying part including a meter which meters an amount of fuel which is used by the fuel cell, and controls the supply of fuel based on said metering.

  8. Direct Methanol Fuel Cell (DMFC) Battery Replacement Program

    DTIC Science & Technology

    2013-01-29

    studies on performance degradation of Catalysts and Nafion™ Membrane Functional Groups in Direct Methanol Fuel Cells, IN PREP (06 2013) TOTAL: 1 Books... 18 Single Cell: Progress...31 Laser Activated Membrane Introduction Mass Spectrometry (LAMIMS) .................................... 37 Future Work (internally

  9. Direct methanol feed fuel cell and system

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2004-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.

  10. Direct methanol feed fuel cell and system

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2008-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.

  11. Direct methanol feed fuel cell and system

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2001-01-01

    Improvements to non acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.

  12. Direct methanol feed fuel cell and system

    NASA Technical Reports Server (NTRS)

    Surampudi, Subbarao (Inventor); Frank, Harvey A. (Inventor); Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Kindler, Andrew (Inventor); Halpert, Gerald (Inventor)

    2000-01-01

    Improvements to non-acid methanol fuel cells include new formulations for materials. The platinum and ruthenium are more exactly mixed together. Different materials are substituted for these materials. The backing material for the fuel cell electrode is specially treated to improve its characteristics. A special sputtered electrode is formed which is extremely porous.

  13. Aerosol feed direct methanol fuel cell

    NASA Technical Reports Server (NTRS)

    Kindler, Andrew (Inventor); Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

    2002-01-01

    Improvements to fuel cells include introduction of the fuel as an aerosol of liquid fuel droplets suspended in a gas. The particle size of the liquid fuel droplets may be controlled for optimal fuel cell performance by selection of different aerosol generators or by separating droplets based upon size using a particle size conditioner.

  14. Directional cell movement through tissues is controlled by exosome secretion

    PubMed Central

    Sung, Bong Hwan; Ketova, Tatiana; Hoshino, Daisuke; Zijlstra, Andries; Weaver, Alissa M.

    2015-01-01

    Directional cell movement through tissues is critical for multiple biological processes and requires maintenance of polarity in the face of complex environmental cues. Here we use intravital imaging to demonstrate that secretion of exosomes from late endosomes is required for directionally persistent and efficient in vivo movement of cancer cells. Inhibiting exosome secretion or biogenesis leads to defective tumour cell migration associated with increased formation of unstable protrusions and excessive directional switching. In vitro rescue experiments with purified exosomes and matrix coating identify adhesion assembly as a critical exosome function that promotes efficient cell motility. Live-cell imaging reveals that exosome secretion directly precedes and promotes adhesion assembly. Fibronectin is found to be a critical motility-promoting cargo whose sorting into exosomes depends on binding to integrins. We propose that autocrine secretion of exosomes powerfully promotes directionally persistent and effective cell motility by reinforcing otherwise transient polarization states and promoting adhesion assembly. PMID:25968605

  15. DIRECT AMMONIA-AIR FUEL CELL.

    DTIC Science & Technology

    fuel cell was investigated. This cell is based on the use of a non-aqueous fused hydroxide electrolyte matrix, and operates in the intermediate temperature range of 180-300 C. Studies have been carried out to determine the nature of the ratecontrolling step in the kinetics of the anodic oxidation of ammonia. A new type of Ni/NiOOH reference electrode was developed for the measurement of single electrode potentials in experimental galvanic fuel cells employing this type of matrix electrolyte. In addition to various exploratory studies, two statistical analysis

  16. TDI can induce respiratory allergy with Th2-dominated response in mice.

    PubMed

    Ban, Masarin; Morel, Georges; Langonné, Isabelle; Huguet, Nelly; Pépin, Elsa; Binet, Stéphane

    2006-01-20

    Toluene diisocyanate (TDI), a highly reactive industrial chemical is one of the leading causes of occupation-related asthma in industrialized countries. The pathophysiology of TDI-induced asthma, however, remains poorly understood, in part due to a lack of appropriate animal models. In this study, four models of TDI-sensitised mice were investigated. In model number 1, the mice were sensitised for 4 h/day on four consecutive days to 3 ppm inhaled TDI and challenged twice for 4 h each time with 0.3 ppm inhaled TDI. In model number 2, the sensitising condition was similar to that of model 1, but the challenge conditions involved an initial inhalation of 2 ppmTDI for 4h and then tracheal instillation with 50 microg/mouse albumin-TDI. In model number 3, the mice were sensitised first to 25% TDI (sc) and then three times for 4 h each time to 1 ppm inhaled TDI and challenged twice for 4h each time with 0.1 ppm inhalated TDI. In model number 4, the mice were first sensitised to 1% TDI by skin application and then with 0.2% TDI by tracheal instillation and challenged tree times by tracheal instillation of 0.1% TDI. In model number 4, skin application followed by tracheal instillations of TDI led to local and systemic Th2-dominated immune responses that were characterized: (1) in the lung-associated lymph nodes by a decrease in Th1 cytokine (IFN-gamma) production associated with an increase in Th2 cytokine (IL-4, IL-5, IL-3) production; (2) in the lungs by an allergic inflammation throughout the conducting airways: goblet cell proliferation and eosinophil influx and; (3) in the serums by increased total and specific IgE levels, 17.5- and 3.5-fold higher than that of the controls, respectively. The conditions used for sensitisation in the other models, i.e. inhalation or subcutaneous administration plus inhalation, failed to induce a strong Th2 response like that observed in model number 4. The findings indicate that TDI can induce a Th2-dominated response in mice when

  17. HIV-specific Th2 and Th17 responses predict HIV vaccine protection efficacy

    PubMed Central

    Sauce, Delphine; Gorochov, Guy; Larsen, Martin

    2016-01-01

    Understanding the factors that delineate the efficacy of T-cell responses towards pathogens is crucial for our ability to develop potent therapies and vaccines against infectious diseases, such as HIV. Here we show that a recently developed analytical tool, the polyfunctionality index (PI), not only enables prediction of protection after vaccination against HIV, but also allows identification of the immunological pathways involved. Our data suggest that induction of a synergistic network of CD4+ T-cell subsets is implicated in HIV-protection. Accordingly, we provide evidence that vaccine-induced protection is associated with CD40L expressing Th2 cells and IL-2 secreting Th17 cells. In conclusion, we describe a novel approach that is widely applicable and readily interpretable in a biological and clinical context. This approach could greatly impact our fundamental understanding of T-cell immunity as well as the search for effective vaccines. PMID:27324186

  18. Direct-Write Contacts for Solar Cells

    SciTech Connect

    Kaydanova, T.; van Hest, M.F.A.M.; Miedaner, A.; Curtis, C. J.; Alleman, J. L.; Dabney, M. S.; Garnett, E.; Shaheen, S.; Ginley, D. S.; Smith, L.; Collins, R.; Hanoka, J. I.; Gabor, A. M.

    2005-01-01

    We report on our project to develop inkjet printable contacts for solar cells. Ag, Cu, and Ni metallizations were inkjet printed with near vacuum deposition quality. Thick, highly conducting lines of Ag and Cu demonstrating good adhesion to glass, Si, and PCB have been printed at 100-200 C in air and N2, respectively. Ag grids were inkjet-printed on Si solar cells and fired through silicon nitride AR layer at 850 C resulting in 8% cells. Next-generation multicomponent inks (including etching agents) have also been developed with improved fire-through contacts leading to higher cell efficiencies. The approach developed can be easily extended to other conductors such as Pt, Pd, and Au, etc. In addition, PEDOT-PSS polymer-based conductors were inkjet-printed with the conductivity as good or better than those of polymer-based conductors.

  19. Tim-3 induces Th2-biased immunity and alternative macrophage activation during Schistosoma japonicum infection.

    PubMed

    Hou, Nan; Piao, Xianyu; Liu, Shuai; Wu, Chuang; Chen, Qijun

    2015-08-01

    T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) has been regarded as an important regulatory factor in both adaptive and innate immunity. Recently, Tim-3 was reported to be involved in Th2-biased immune responses in mice infected with Schistosoma japonicum, but the exact mechanism behind the involvement of Tim-3 remains unknown. The present study aims to understand the role of Tim-3 in the immune response against S. japonicum infection. Tim-3 expression was determined by flow cytometry, and increased Tim-3 expression was observed on CD4(+) and CD8(+) T cells, NK1.1(+) cells, and CD11b(+) cells from the livers of S. japonicum-infected mice. However, the increased level of Tim-3 was lower in the spleen than in the liver, and no increase in Tim-3 expression was observed on splenic CD8(+) T cells or CD11b(+) cells. The schistosome-induced upregulation of Tim-3 on natural killer (NK) cells was accompanied by reduced NK cell numbers in vitro and in vivo. Tim-3 antibody blockade led to upregulation of inducible nitric oxide synthase and interleukin-12 (IL-12) mRNA in CD11b(+) cells cocultured with soluble egg antigen and downregulation of Arg1 and IL-10, which are markers of M2 macrophages. In summary, we observed schistosome-induced expression of Tim-3 on critical immune cell populations, which may be involved in the Th2-biased immune response and alternative activation of macrophages during infection.

  20. Tim-3 Induces Th2-Biased Immunity and Alternative Macrophage Activation during Schistosoma japonicum Infection

    PubMed Central

    Hou, Nan; Piao, Xianyu; Liu, Shuai; Wu, Chuang

    2015-01-01

    T cell immunoglobulin- and mucin-domain-containing molecule 3 (Tim-3) has been regarded as an important regulatory factor in both adaptive and innate immunity. Recently, Tim-3 was reported to be involved in Th2-biased immune responses in mice infected with Schistosoma japonicum, but the exact mechanism behind the involvement of Tim-3 remains unknown. The present study aims to understand the role of Tim-3 in the immune response against S. japonicum infection. Tim-3 expression was determined by flow cytometry, and increased Tim-3 expression was observed on CD4+ and CD8+ T cells, NK1.1+ cells, and CD11b+ cells from the livers of S. japonicum-infected mice. However, the increased level of Tim-3 was lower in the spleen than in the liver, and no increase in Tim-3 expression was observed on splenic CD8+ T cells or CD11b+ cells. The schistosome-induced upregulation of Tim-3 on natural killer (NK) cells was accompanied by reduced NK cell numbers in vitro and in vivo. Tim-3 antibody blockade led to upregulation of inducible nitric oxide synthase and interleukin-12 (IL-12) mRNA in CD11b+ cells cocultured with soluble egg antigen and downregulation of Arg1 and IL-10, which are markers of M2 macrophages. In summary, we observed schistosome-induced expression of Tim-3 on critical immune cell populations, which may be involved in the Th2-biased immune response and alternative activation of macrophages during infection. PMID:25987707

  1. Th1 and Th2 immune response to P30 and ROP18 peptides in human toxoplasmosis.

    PubMed

    Torres-Morales, Elizabeth; Taborda, Laura; Cardona, Nestor; De-la-Torre, Alejandra; Sepulveda-Arias, Juan Carlos; Patarroyo, Manuel Alfonso; Gomez-Marin, Jorge Enrique

    2014-10-01

    We determined the specific lymphocyte proliferative response and cytokine profile production regarding Toxoplasma P30 (2017 from virulent and non-virulent strain) and ROP18 protein-derived peptides (from clonal lineages I, II and III) in 19 patients having ocular toxoplasmosis, five suffering chronic asymptomatic infection, nine with congenital toxoplasmosis and eight Toxoplasma negative people. A Beckman Coulter FC500 flow cytometer was used for determining antigen-specific T cells (CD3+ CD4+ or CD3+ CD8+ cells) in peripheral blood culture. IFN γ and IL10 levels were determined in culture supernatants. Specific CD4+ and CD8+ T cell response to total antigen and P30- and ROP18-derived peptides was observed in infected people. Ocular toxoplasmosis patients had a preferential Th2 response after antigenic stimulation. Non-virulent peptide 2017 was able to shift response toward Th1 in congenitally infected children and virulent peptide 2017 induced a Th2 response in chronically infected, asymptomatic people. An immune response in human toxoplasmosis after ex vivo antigenic stimulation was Th1- or Th2-skewed, depending on a patient's clinical condition. Colombian ocular toxoplasmosis patients' immune response was Th2-skewed, regardless of the nature of antigen stimulus.

  2. Direct Write Contacts for Solar Cells

    SciTech Connect

    Kaydanova, T.; van Hest, M.F.A.M.; Miedaner, A.; Curtis, C. J.; Alleman, J. L.; Dabney, M. S.; Garnett, E.; Shaheen, S.; Smith, L.; Collins, R.; Hanoka, J. I.; Gabor, A. M.; Ginley, D.S.

    2005-02-01

    Ag, Cu, and Ni metallizations were inkjet-printed with near-vacuum deposition quality. The approach developed can be easily extended to other conductors such as Pt, Pd, and Au. Thick, highly conducting lines of Ag and Cu demonstrating good adhesion to glass, Si, and PCB have been printed at 100-200 C in air and N2, respectively. Ag grids were inkjet-printed on Si solar cells and fired through the silicon nitride antireflective layer at 850 C resulting in 8%-efficient cells. Next-generation multicomponent inks (including etching agents) have also been developed with improved fire-through contacts leading to higher cell efficiencies. PEDOT-PSS polymer-based conductors were inkjet-printed with conductivity as good or better than that of spin-coated films.

  3. Stromal Cell Subsets Directing Neonatal Spleen Regeneration

    PubMed Central

    Tan, Jonathan K. H.; Watanabe, Takeshi

    2017-01-01

    Development of lymphoid tissue is determined by interactions between stromal lymphoid tissue organiser (LTo) and hematopoietic lymphoid tissue inducer (LTi) cells. A failure for LTo to receive appropriate activating signals during embryogenesis through lymphotoxin engagement leads to a complete cessation of lymph node (LN) and Peyer’s patch development, identifying LTo as a key stromal population for lymphoid tissue organogenesis. However, little is known about the equivalent stromal cells that induce spleen development. Here, by dissociating neonatal murine spleen stromal tissue for re-aggregation and transplant into adult mouse recipients, we have identified a MAdCAM-1+CD31+CD201+ spleen stromal organizer cell-type critical for new tissue formation. This finding provides an insight into the regulation of post-natal spleen tissue organogenesis, and could be exploited in the development of spleen regenerative therapies. PMID:28067323

  4. New directions in InP solar cell research

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Swartz, C. K.; Brinker, D. J.

    1990-01-01

    Recent research efforts representing new directions in InP solar cell research are reviewed. These include heteroepitaxial growth on silicon and gallium arsenide substrates, V-grooved cells, large area high efficiency cells, and surface passivation. Improvements in heteroepitaxial cell efficiency are described together with processing of 19.1 percent, 4 sq cm cells. Recommendations are made for improvements in processing leading to increased efficiencies.

  5. Apigenin Attenuates Experimental Autoimmune Myocarditis by Modulating Th1/Th2 Cytokine Balance in Mice.

    PubMed

    Zhang, Shouxin; Liu, Xiaoyan; Sun, Chengming; Yang, Jun; Wang, Lihong; Liu, Jie; Gong, Lei; Jing, Yanyan

    2016-04-01

    This study aims to investigate the protective effect of apigenin on the development of experimental autoimmune myocarditis (EAM) and the underlying mechanisms. An EAM model was induced in BALB/c mice by the injection of porcine cardiac myosin. Apigenin was orally administered from day 1 to 21. The severity of myocarditis was assessed by determination of heart weight/body weight ratio (HW/BW) and histopathological evaluation. Echocardiography was conducted to evaluate the cardiac function and heart structure. Antigen-specific T cell proliferation responses to cardiac myosin were evaluated by the lymphocyte proliferation assay. ELISA was used to determine serum levels of type 1 helper (Th1) and Th2 cytokines. Apigenin treatment significantly decreased HW/BW. Histopathologic analysis showed that the infiltration of inflammatory cells was reduced significantly by apigenin treatment. Meanwhile, apigenin administration effectively ameliorated autoimmune myocarditis-induced cardiac hypertrophy and cardiac dysfunction as well as inhibited lymphocyte proliferation in mice immunized with myosin. Furthermore, Th1 cytokines tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and interleukin-2 (IL-2) were significantly downregulated, while Th2 cytokines IL-4 and IL-10 were markedly upregulated. The results indicated that apigenin can alleviate EAM due to its immunomodulatory reactions in modification of helper T cell balance.

  6. Leader Cells Define Directionality of Trunk, but Not Cranial, Neural Crest Cell Migration.

    PubMed

    Richardson, Jo; Gauert, Anton; Briones Montecinos, Luis; Fanlo, Lucía; Alhashem, Zainalabdeen Mohmammed; Assar, Rodrigo; Marti, Elisa; Kabla, Alexandre; Härtel, Steffen; Linker, Claudia

    2016-05-31

    Collective cell migration is fundamental for life and a hallmark of cancer. Neural crest (NC) cells migrate collectively, but the mechanisms governing this process remain controversial. Previous analyses in Xenopus indicate that cranial NC (CNC) cells are a homogeneous population relying on cell-cell interactions for directional migration, while chick embryo analyses suggest a heterogeneous population with leader cells instructing directionality. Our data in chick and zebrafish embryos show that CNC cells do not require leader cells for migration and all cells present similar migratory capacities. In contrast, laser ablation of trunk NC (TNC) cells shows that leader cells direct movement and cell-cell contacts are required for migration. Moreover, leader and follower identities are acquired before the initiation of migration and remain fixed thereafter. Thus, two distinct mechanisms establish the directionality of CNC cells and TNC cells. This implies the existence of multiple molecular mechanisms for collective cell migration.

  7. Distinct Th1- and Th2-Type prenatal cytokine responses to Plasmodium falciparum erythrocyte invasion ligands.

    PubMed

    Malhotra, Indu; Mungai, Peter; Muchiri, Eric; Ouma, John; Sharma, Shobhona; Kazura, James W; King, Christopher L

    2005-06-01

    Prenatal immunity to Plasmodium falciparum merozoite proteins involved in erythrocyte invasion may contribute to the partial protection against malaria that is acquired during infancy in areas of stable malaria transmission. We examined newborn and maternal cytokine and antibody responses to merozoite surface protein-1 (MSP-1), ribosomal phosphoprotein P0 (PfP0), and region II of erythrocyte binding antigen-175 (EBA-175) in infant-mother pairs in Kenya. Overall, 82 of 167 (50%), 106 of 176 (60%), and 38 of 84 (45%) cord blood lymphocytes (CBL) from newborns produced one or more cytokines in response to MSP-1, PfP0, and EBA-175, respectively. Newborns of primigravid and/or malaria-infected women were more likely to have antigen-responsive CBL than were newborns of multigravid and/or uninfected women at delivery. Newborn cytokine responses did not match those of their mothers and fell into three distinct categories, Th1 (21 of 55 CBL donors produced only gamma interferon and/or interleukin 2 [IL-2]), Th2 (21 of 55 produced only IL-5 and/or IL-13), and mixed Th1/Th2 (13 of 55). Newborns produced more IL-10 than adults. High and low levels of cord blood IL-12 p70 production induced by anti-CD40 activation were associated with malaria-specific Th1 and Th2 responses, respectively. Antigen-responsive CBL in some newborns were detected only after depletion of IL-10-secreting CD8 cells with enrichment for CD4 cells. These data indicate that prenatal sensitization to blood-stage Plasmodium falciparum occurs frequently in areas where malaria is holoendemic. Modulation of this immunity, possibly by maternal parity and malaria, may affect the acquisition of protective immunity against malaria during infancy.

  8. Sexual activity modulates shifts in Th1/Th2 cytokine profile across the menstrual cycle: An observational study

    PubMed Central

    Lorenz, Tierney K.; Heiman, Julia R.; Demas, Gregory E.

    2015-01-01

    Objective To investigate if sexual activity moderated menstrual cycle-related shifts in cytokines associated with helper-T type 1 (Th1) cells (e.g., interferon-γ, IFN-γ) and helper T type 2 (Th2) cells (e.g., interleukin-4, IL-4). Immune activity shifts across the menstrual cycle, with higher follicular-phase Th1 cell activity, but higher luteal-phase Th2 cell activity There is little known about how social behaviors alter Th1/Th2 ratios, despite evidence that psychosocial factors can influence immunity. Of particular interest is how sexual activity influences immune responses that may support conception, such as the Th1/Th2 balance. Design Participants provided saliva samples at four timepoints (menstrual, follicular, ovulatory, and luteal), which were assayed using enzyme-linked immunosorbent assays (ELISA). Setting Academic laboratory. Participants Thirty healthy premenopausal women (16 sexually abstinent, 14 sexually active), not taking hormonal or immunoactive medications. Interventions None. Main outcome measures Salivary estradiol (E2), progesterone (P4), IFN-γ, IL-4. Results Sexually active, but not abstinent, women were significantly more likely to express Th2-like cytokine ratios (IFN-γ < IL-4) in the luteal phase than other phases. Similarly, sexually active women had significantly higher P4, and higher P4 to E2 (P/E) ratios, in the luteal phase than did abstinent women. The P/E ratio mediated menstrual variations in cytokine ratios in sexually active women. Conclusion These results support the hypothesis that shifts in immune response across the menstrual cycle may reflect tradeoffs between reproduction and immunity. These findings point to the need for further research on the interaction between sexual behavior, the menstrual cycle, and immune response. PMID:26385401

  9. Electron-beam direct processing on living cell membrane

    SciTech Connect

    Hoshino, Takayuki; Morishima, Keisuke

    2011-10-24

    We demonstrated a direct processing on a living Hep G2 cell membrane in conventional cultivation conditions using an electron beam. Electron beam-induced deposition from liquid precursor 3,4-ethylenedioxythiophene and ablation was performed on the living cells. The 2.5-10 keV electron beam which was irradiated through a 100-nm-thick SiN nanomembrane could induce a deposition pattern and a ablation on a living cell membrane. This electron beam direct processing can provide simple in-situ cell surface modification for an analytical method of living cell membrane dynamic.

  10. Peptide dose, affinity, and time of differentiation can contribute to the Th1/Th2 cytokine balance.

    PubMed

    Rogers, P R; Croft, M

    1999-08-01

    Opposing viewpoints exist regarding how Ag dose and affinity modulate Th1/Th2 differentiation, with data suggesting that both high and low level stimulation favors Th2 responses. With transgenic T cells bearing a single TCR, we present novel data, using peptides differing in affinity for the TCR, that show that the time period of differentiation can determine whether Th1 or Th2 responses predominate as the level of initial stimulation is altered. Over the short term, IFN-gamma-producing cells were induced by lower levels of stimulation than IL-4-producing cells, although optimal induction of both was seen with the same high level of stimulation. Over the long term, however, high doses of high affinity peptides led selectively to IFN-gamma-secreting cells, whereas IL-4- and IL-5-secreting cells predominated with lower levels of initial signaling, brought about by moderate doses of high affinity peptides. In contrast, too low a level of stimulation at the naive T cell stage, with low affinity peptides at any concentration, promoted only IL-2-secreting effectors or was not sufficient for long term T cell survival. These results demonstrate that the level of signaling achieved through the TCR is intimately associated with the induction of distinct cytokine-secreting T cells. We show that dose, affinity, time over which differentiation occurs, and initial production of IL-4 and IFN-gamma all can contribute to which T cell subset will predominate. Furthermore, these data reconcile the two opposing views on the effects of dose and affinity and provide a unifying model of Th1/Th2 differentiation based on strength of signaling and length of response.

  11. Encoding of head direction by hippocampal place cells in bats.

    PubMed

    Rubin, Alon; Yartsev, Michael M; Ulanovsky, Nachum

    2014-01-15

    Most theories of navigation rely on the concept of a mental map and compass. Hippocampal place cells are neurons thought to be important for representing the mental map; these neurons become active when the animal traverses a specific location in the environment (the "place field"). Head-direction cells are found outside the hippocampus, and encode the animal's head orientation, thus implementing a neural compass. The prevailing view is that the activity of head-direction cells is not tuned to a single place, while place cells do not encode head direction. However, little work has been done to investigate in detail the possible head-directional tuning of hippocampal place cells across species. Here we addressed this by recording the activity of single neurons in the hippocampus of two evolutionarily distant bat species, Egyptian fruit bat and big brown bat, which crawled randomly in three different open-field arenas. We found that a large fraction of hippocampal neurons, in both bat species, showed conjunctive sensitivity to the animal's spatial position (place field) and to its head direction. We introduced analytical methods to demonstrate that the head-direction tuning was significant even after controlling for the behavioral coupling between position and head direction. Surprisingly, some hippocampal neurons preserved their head direction tuning even outside the neuron's place field, suggesting that "spontaneous" extra-field spikes are not noise, but in fact carry head-direction information. Overall, these findings suggest that bat hippocampal neurons can convey both map information and compass information.

  12. Chitin recognition via chitotriosidase promotes pathologic type-2 helper T cell responses to cryptococcal infection.

    PubMed

    Wiesner, Darin L; Specht, Charles A; Lee, Chrono K; Smith, Kyle D; Mukaremera, Liliane; Lee, S Thera; Lee, Chun G; Elias, Jack A; Nielsen, Judith N; Boulware, David R; Bohjanen, Paul R; Jenkins, Marc K; Levitz, Stuart M; Nielsen, Kirsten

    2015-03-01

    Pulmonary mycoses are often associated with type-2 helper T (Th2) cell responses. However, mechanisms of Th2 cell accumulation are multifactorial and incompletely known. To investigate Th2 cell responses to pulmonary fungal infection, we developed a peptide-MHCII tetramer to track antigen-specific CD4+ T cells produced in response to infection with the fungal pathogen Cryptococcus neoformans. We noted massive accruement of pathologic cryptococcal antigen-specific Th2 cells in the lungs following infection that was coordinated by lung-resident CD11b+ IRF4-dependent conventional dendritic cells. Other researchers have demonstrated that this dendritic cell subset is also capable of priming protective Th17 cell responses to another pulmonary fungal infection, Aspergillus fumigatus. Thus, higher order detection of specific features of fungal infection by these dendritic cells must direct Th2 cell lineage commitment. Since chitin-containing parasites commonly elicit Th2 responses, we hypothesized that recognition of fungal chitin is an important determinant of Th2 cell-mediated mycosis. Using C. neoformans mutants or purified chitin, we found that chitin abundance impacted Th2 cell accumulation and disease. Importantly, we determined Th2 cell induction depended on cleavage of chitin via the mammalian chitinase, chitotriosidase, an enzyme that was also prevalent in humans experiencing overt cryptococcosis. The data presented herein offers a new perspective on fungal disease susceptibility, whereby chitin recognition via chitotriosidase leads to the initiation of harmful Th2 cell differentiation by CD11b+ conventional dendritic cells in response to pulmonary fungal infection.

  13. TET1 and TET3 are essential in induction of Th2-type immunity partly through regulation of IL-4/13A expression in zebrafish model.

    PubMed

    Yang, Chao; Li, Zhuo; Kang, Wei; Tian, Yu; Yan, Yuzhu; Chen, Wei

    2016-10-10

    It has been considered that epigenetic modulation can affect a diverse array of cellular activities, in which ten eleven translocation (TET) methylcytosine dioxygenase family members refer to a group of fundamental components involved in catalyzation of 5-hydroxymethylcytosine and modification of gene expression. Even though the function of TET proteins has been gradually revealed, their roles in immune regulation are still largely unknown. Recent studies provided clues that TET2 could regulate several innate immune-related inflammatory mediators in mammals. This study sought to explore the function of TET family members in potential T-helper (Th) cell differentiation involved in adaptive immunity by utilizing a zebrafish model. As shown by results, soluble antigens could induce expression of zebrafish IL-4/13A (i.e. a pivotal Th2-type cytokine essential in Th2 cell differentiation and functions), and further trigger the expression of Th1- and Th2-related genes. It is noteworthy that this response was accompanied by the up-regulation of two TET family members (TET1 and TET3) both in immune organs (spleen and kidney) and cells (peripheral lymphocytes). Knocking-down of TET1 and TET3 will give rise to the decreased responses of IL-4/13A induction against exogenous soluble antigen stimulation, and further restrain the expression of Th2-related genes, which indicates a restrained Th2 cell differentiation. Nonetheless, TET2 did not exhibit effect on the modification of Th1/Th2 related gene expression. Hence, these data showed that TET1 and TET3 might be two significant epigenetic regulators involved in Th2 differentiation through regulation of IL-4/13A expression. This is the first report to show that TET family members play indispensable roles in Th2-type immunity, indicating an epigenetic modulation manner involved in adaptive immune regulations and responses.

  14. Direct methanol fuel cell and system

    DOEpatents

    Wilson, Mahlon S.

    2004-10-26

    A fuel cell having an anode and a cathode and a polymer electrolyte membrane located between anode and cathode gas diffusion backings uses a methanol vapor fuel supply. A permeable polymer electrolyte membrane having a permeability effective to sustain a carbon dioxide flux equivalent to at least 10 mA/cm.sup.2 provides for removal of carbon dioxide produced at the anode by reaction of methanol with water. Another aspect of the present invention includes a superabsorpent polymer material placed in proximity to the anode gas diffusion backing to hold liquid methanol or liquid methanol solution without wetting the anode gas diffusion backing so that methanol vapor from the liquid methanol or liquid methanol-water solution is supplied to the membrane.

  15. DIRECT FUEL CELL/TURBINE POWER PLANT

    SciTech Connect

    Hossein Ghezel-Ayagh

    2003-05-27

    The subMW hybrid DFC/T power plant facility was upgraded with a Capstone C60 microturbine and a state-of-the-art full size fuel cell stack. The integration of the larger microturbine extended the capability of the hybrid power plant to operate at high power ratings with a single gas turbine without the need for supplementary air. The objectives of this phase of subMW hybrid power plant tests are to support the development of process and control and to provide the insight for the design of the packaged subMW hybrid demonstration units. The development of the ultra high efficiency multi-MW power plants was focused on the design of 40 MW power plants with efficiencies approaching 75% (LHV of natural gas). The design efforts included thermodynamic cycle analysis of key gas turbine parameters such as compression ratio.

  16. Direct deposit of catalyst on the membrane of direct feed fuel cells

    NASA Technical Reports Server (NTRS)

    Chun, William (Inventor); Narayanan, Sekharipuram R. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Valdez, Thomas I. (Inventor); Linke, Juergen (Inventor)

    2001-01-01

    An improved direct liquid-feed fuel cell having a solid membrane electrolyte for electrochemical reactions of an organic fuel. Catalyst utilization and catalyst/membrane interface improvements are disclosed. Specifically, the catalyst layer is applied directly onto the membrane electrolyte.

  17. Controlling mechanisms in directional growth of aggregated archaeal cells.

    PubMed

    Milkevych, Viktor; Batstone, Damien J

    2014-12-28

    Members of the family Methanosarcinaceae are important archaeal representatives due to their broad functionality, ubiquitous presence, and functionality in harsh environments. A key characteristic is their multicellular (packet) morphology represented by aggregates of spatially confined cells. This morphology is driven by directed growth of cells in confinement with sequential variation in growth direction. To further understand why spatially confined Methanosarcina cells (and in general, confined prokaryotes) change their direction of growth during consecutive growth-division stages, and how a particular cell senses its wall topology and responds to changes on it a theoretical model for stress dependent growth of aggregated archaeal cells was developed. The model utilizes a confined elastic shell representation of aggregated archaeal cell and is derived based on a work-energy principle. The growth law takes into account the fine structure of archaeal cell wall, polymeric nature of methanochondroitin layer, molecular-biochemical processes and is based on thermodynamic laws. The developed model has been applied to three typical configurations of aggregated cell in 3D. The developed model predicted a geometry response with delayed growth of aggregated archaeal cells explained from mechanistic principles, as well as continuous changes in direction of growth during the consecutive growth-division stages. This means that cell wall topology sensing and growth anisotropy can be predicted using simple cellular mechanisms without the need for dedicated cellular machinery.

  18. Monocyte chemoattractant protein-1 enhances HSV-induced encephalomyelitis by stimulating Th2 responses.

    PubMed

    Nakajima, H; Kobayashi, M; Pollard, R B; Suzuki, F

    2001-09-01

    Monocyte chemoattractant protein (MCP)-1 has a pathogenic role in herpesvirus-induced encephalomyelitis (HSM). Anti-MCP-1 antibody greatly decreased HSM severity in mice infected with herpes simplex virus type 2 (HSM mice), compared with its effect in control HSM mice treated with rabbit immunoglobulin. HSM severity was markedly enhanced in mice previously treated with a mixture of interleukin (IL) 4 and -10. In response to stimulation with antigen, HSM mouse cells isolated from cerebrospinal fluids (CSF cells) produced IL-4 in culture fluids; however, IL-4 production decreased in CSF cells derived from HSM mice previously treated with anti-MCP-1 antibody. A macrophage population isolated in CSF cells from HSM mice (CSF-Mphi) produced MCP-1 in culture fluids. In response to stimulation with herpesvirus antigen, a population of T cells isolated from CSF cells from HSM mice (CSF-T cells) produced IL-4 into their culture fluids, although MCP-1 was not produced by CSF-T cells stimulated by this antigen. IL-4 production by CSF-T cells was markedly enhanced when they were stimulated with viral antigen in the presence of murine recombinant MCP-1 (rMCP-1). Furthermore, IL-4 was produced in naive splenic T cells cocultured with CSF-Mphi. These results indicate that the severity of HSM is influenced by MCP-1, which stimulates Th2 responses.

  19. Generation of diverse neural cell types through direct conversion

    PubMed Central

    Petersen, Gayle F; Strappe, Padraig M

    2016-01-01

    A characteristic of neurological disorders is the loss of critical populations of cells that the body is unable to replace, thus there has been much interest in identifying methods of generating clinically relevant numbers of cells to replace those that have been damaged or lost. The process of neural direct conversion, in which cells of one lineage are converted into cells of a neural lineage without first inducing pluripotency, shows great potential, with evidence of the generation of a range of functional neural cell types both in vitro and in vivo, through viral and non-viral delivery of exogenous factors, as well as chemical induction methods. Induced neural cells have been proposed as an attractive alternative to neural cells derived from embryonic or induced pluripotent stem cells, with prospective roles in the investigation of neurological disorders, including neurodegenerative disease modelling, drug screening, and cellular replacement for regenerative medicine applications, however further investigations into improving the efficacy and safety of these methods need to be performed before neural direct conversion becomes a clinically viable option. In this review, we describe the generation of diverse neural cell types via direct conversion of somatic cells, with comparison against stem cell-based approaches, as well as discussion of their potential research and clinical applications. PMID:26981169

  20. Naive Pluripotent Stem Cells Derived Directly from Isolated Cells of the Human Inner Cell Mass

    PubMed Central

    Guo, Ge; von Meyenn, Ferdinand; Santos, Fatima; Chen, Yaoyao; Reik, Wolf; Bertone, Paul; Smith, Austin; Nichols, Jennifer

    2016-01-01

    Summary Conventional generation of stem cells from human blastocysts produces a developmentally advanced, or primed, stage of pluripotency. In vitro resetting to a more naive phenotype has been reported. However, whether the reset culture conditions of selective kinase inhibition can enable capture of naive epiblast cells directly from the embryo has not been determined. Here, we show that in these specific conditions individual inner cell mass cells grow into colonies that may then be expanded over multiple passages while retaining a diploid karyotype and naive properties. The cells express hallmark naive pluripotency factors and additionally display features of mitochondrial respiration, global gene expression, and genome-wide hypomethylation distinct from primed cells. They transition through primed pluripotency into somatic lineage differentiation. Collectively these attributes suggest classification as human naive embryonic stem cells. Human counterparts of canonical mouse embryonic stem cells would argue for conservation in the phased progression of pluripotency in mammals. PMID:26947977

  1. Lattice-free models of directed cell motility

    NASA Astrophysics Data System (ADS)

    Irons, Carolyn; Plank, Michael J.; Simpson, Matthew J.

    2016-01-01

    Directed cell migration often occurs when individual cells move in response to an external chemical stimulus. Cells can respond by moving in either the direction of increasing (chemoattraction) or decreasing (chemorepulsion) concentration. Many previous models of directed cell migration use a lattice-based framework where agents undergo a lattice-based random walk and the direction of nearest-neighbour motility events is biased in a preferred direction. Such lattice-based models can lead to unrealistic configurations of agents, since the agents always move on an artificial lattice structure which is never observed experimentally. We present a lattice-free model of directed cell migration that incorporates two key features. First, agents move on a continuous domain, with the possibility that there is some preferred direction of motion. Second, to be consistent with experimental observations, we enforce a crowding mechanism so that motility events that would lead to agent overlap are not permitted. We compare simulation data from the new lattice-free model with a more traditional lattice-based model. To provide additional insight into the lattice-free model, we construct an approximate conservation statement which corresponds to a nonlinear advection-diffusion equation in the continuum limit. The solution of this mean-field model compares well with averaged data from the individual-based model.

  2. MicroRNA-138 regulates the balance of Th1/Th2 via targeting RUNX3 in psoriasis.

    PubMed

    Fu, Dandan; Yu, Wenfa; Li, Min; Wang, Huimin; Liu, Dong; Song, Xiangfeng; Li, Zhanguo; Tian, Zhongwei

    2015-07-01

    Psoriasis is a common chronic inflammatory and T cell-meditated autoimmune skin disease. A recent study found that Runt-related transcription factor 3 (RUNX3) is a susceptibility gene for psoriasis; however, its biological role in the disease has not been studied. RUNX3 was predicted to be the target gene of microRNA-138 (miR-138). The current research was designed to delineate the mechanism of miR-138 in regulating psoriasis via targeting RUNX3. In this study, we found that the expression of RUNX3 is increased significantly while the expression of miR-138 decreased significantly in CD4(+) T cells from psoriasis patients. Moreover, the luciferase report confirmed the targeting reaction between miR-138 and RUNX3. After transfection with the miR-138 inhibitor into CD4(+) T cells from healthy controls, we found that the inhibition of miR-138 increases RUNX3 expression and increased the ratio of Th1/Th2. Furthermore, the miR-138 mimic was transfected into CD4(+) T cells from psoriasis patients. The results showed that the overexpression of miR-138 inhibits RUNX3 expression and decreased the ratio of Th1/Th2 in CD4(+) T cells. Taken together, our study suggests that increased miR-138 regulates the balance of Th1/Th2 through inhibiting RUNX3 expression in psoriasis, providing a potential therapeutic target for psoriasis.

  3. Chemokines fail to up-regulate beta 1 integrin-dependent adhesion in human Th2 T lymphocytes.

    PubMed

    Clissi, B; D'Ambrosio, D; Geginat, J; Colantonio, L; Morrot, A; Freshney, N W; Downward, J; Sinigaglia, F; Pardi, R

    2000-03-15

    Th1 and Th2 cells are functionally distinct subsets of CD4+ T lymphocytes whose tissue-specific homing to sites of inflammation is regulated in part by the differential expression of P- and E-selectin ligands and selected chemokine receptors. Here we investigated the expression and function of beta 1 integrins in Th1 and Th2 cells polarized in vitro. Th1 lymphocytes adhere transiently to the extracellular matrix ligands laminin 1 and fibronectin in response to chemokines such as RANTES and stromal cell-derived factor-1, and this process is paralleled by the activation of the Rac1 GTPase and by a rapid burst of actin polymerization. Selective inhibitors of phosphoinositide-3 kinase prevent efficiently all of the above processes, whereas the protein kinase C inhibitor bisindolylmaleimide prevents chemokine-induced adhesion without affecting Rac1 activation and actin polymerization. Notably, chemokine-induced adhesion to beta 1 integrin ligands is markedly reduced in Th2 cells. Such a defect cannot be explained by a reduced sensitivity to chemokine stimulation in this T cell subset, nor by a defective activation of the signaling cascade involving phosphoinositide-3 kinase, Rac1, and actin turnover, as all these processes are activated at comparable levels by chemokines in the two subsets. We propose that reduced beta 1 integrin-mediated adhesion in Th2 cells may restrain their ability to invade and/or reside in sites of chronic inflammation, which are characterized by thickening of basement membranes and extensive fibrosis, requiring efficient interaction with organized extracellular matrices.

  4. A direct 2-propanol polymer electrolyte fuel cell

    NASA Astrophysics Data System (ADS)

    Cao, Dianxue; Bergens, Steven H.

    We report the performance of a polymer electrolyte membrane direct 2-propanol fuel cell (DPFC). The cell consisted of a Pt-Ru (atomic ratio of 1:1) black anode, a Pt black cathode, and a Nafion ®-117 membrane electrolyte. The cell was operated at 90 °C with aqueous 2-propanol as fuel and with oxygen as oxidant. The performance of the cell operating on 2-propanol is substantially higher than when it was operating on methanol at current densities lower than ˜200 mA/cm 2. The electrical efficiency of the direct 2-propanol fuel cell is nearly 1.5 times that of the direct methanol fuel cell at power densities below 128 mW/cm 2. Studies on the effects of electrocatalyst loading, of 2-propanol concentration, and of oxygen pressure on cell performance indicate that the cells operating on 2-propanol require lower anode and cathode loadings than cells operating on methanol. Cathode poisoning by 2-propanol is less severe than by methanol. Hydrogen gas evolution observed at the anode at low current densities indicated that catalytic dehydrogenation of 2-propanol occurred over the anode catalyst. A rapid voltage drop occurred at high current densities and after operating the cell for extended periods of time at constant current. The rapid voltage drop is an anode phenomenon.

  5. Notch ligand delta-like 4 regulates development and pathogenesis of allergic airway responses by modulating IL-2 production and Th2 immunity.

    PubMed

    Jang, Sihyug; Schaller, Matthew; Berlin, Aaron A; Lukacs, Nicholas W

    2010-11-15

    Activation of the canonical Notch pathways has been implicated in Th cell differentiation, but the role of specific Notch ligands in Th2-mediated allergic airway responses has not been completely elucidated. In this study, we show that delta-like ligand 4 (Dll4) was upregulated on dendritic cells in response to cockroach allergen. Blocking Dll4 in vivo during either the primary or secondary response enhanced allergen-induced pathogenic consequences including airway hyperresponsiveness and mucus production via increased Th2 cytokines. In vitro assays demonstrated that Dll4 regulates IL-2 in T cells from established Th2 responses as well as during primary stimulation. Notably, Dll4 blockade during the primary, but not the secondary, response increased IL-2 levels in lung and lymph node of allergic mice. The in vivo neutralization of Dll4 was associated with increased expansion and decreased apoptosis during the primary allergen sensitization. Moreover, Dll4-mediated Notch activation of T cells during primary stimulation in vitro increased apoptosis during the contraction/resting phase of the response, which could be rescued by exogenous IL-2. Consistent with the role for Dll4-mediated IL-2 regulation in overall T cell function, the frequency of IL-4-producing cells was also significantly altered by Dll4 both in vivo and in vitro. These data demonstrate a regulatory role of Dll4 both in initial Th2 differentiation and in Th2 cytokine production in established allergic responses.

  6. On direct and indirect methanol fuel cells for transportation applications

    SciTech Connect

    Ren, Xiaoming; Wilson, M.S.; Gottesfeld, S.

    1995-09-01

    Power densities in electrolyte Direct Methanol Fuel Cells have been achieved which are only three times lower than those achieved with similar reformate/air fuel cells. Remaining issues are: improved anode catalyst activity, demonstrated long-term stable performance, and high fuel efficiencies.

  7. Parametric Design Studies on a Direct Liquid Feed Fuel Cell

    NASA Technical Reports Server (NTRS)

    Frank, H. A.; Narayanan, S. R.; Nakamura, B.; Surampudi, S.; Halpert, G.

    1995-01-01

    Parametric design studies were carried out on a direct methanol liquid feed fuel cell employing 1 M MeOH fuel, air and oxygen as oxidant in a 2 inch x 2 inch cell employing polymeric electrolyte membranes. Measurements include voltage-current output parameters, methanol crossover rate, and impedance as a function of several design and operational variables. Design variables are described.

  8. On direct and indirect methanol fuel cells for transportation applications

    SciTech Connect

    Gottesfield, S.

    1996-04-01

    Research on direct oxidation methanol fuel cells (DMFCs) and polymer electrolyte fuel cells (PEFCs) is discussed. Systems considered for transportation applications are addressed. The use of platinum/ruthenium anode electrocatalysts and platinum cathode electrocatalysts in polymer electrolyte DMFCs has resulted in significant performance enhancements.

  9. Paxillin-kinase-linker tyrosine phosphorylation regulates directional cell migration.

    PubMed

    Yu, Jianxin A; Deakin, Nicholas O; Turner, Christopher E

    2009-11-01

    Directed cell migration requires the coordination of growth factor and cell adhesion signaling and is of fundamental importance during embryonic development, wound repair, and pathological conditions such as tumor metastasis. Herein, we demonstrate that the ArfGAP, paxillin-kinase-linker (PKL/GIT2), is tyrosine phosphorylated in response to platelet-derived growth factor (PDGF) stimulation, in an adhesion dependent manner and is necessary for directed cell migration. Using a combination of pharmacological inhibitors, knockout cells and kinase mutants, FAK, and Src family kinases were shown to mediate PDGF-dependent PKL tyrosine phosphorylation. In fibroblasts, expression of a PKL mutant lacking the principal tyrosine phosphorylation sites resulted in loss of wound-induced cell polarization as well as directional migration. PKL phosphorylation was necessary for PDGF-stimulated PKL binding to the focal adhesion protein paxillin and expression of paxillin or PKL mutants defective in their respective binding motifs recapitulated the polarization defects. RNA interference or expression of phosphorylation mutants of PKL resulted in disregulation of PDGF-stimulated Rac1 and PAK activities, reduction of Cdc42 and Erk signaling, as well as mislocalization of betaPIX. Together these studies position PKL as an integral component of growth factor and cell adhesion cross-talk signaling, controlling the development of front-rear cell polarity and directional cell migration.

  10. Directed differentiation of pluripotent stem cells to kidney cells.

    PubMed

    Lam, Albert Q; Freedman, Benjamin S; Bonventre, Joseph V

    2014-07-01

    Regenerative medicine affords a promising therapeutic strategy for the treatment of patients with chronic kidney disease. Nephron progenitor cell populations exist only during embryonic kidney development. Understanding the mechanisms by which these populations arise and differentiate is integral to the challenge of generating new nephrons for therapeutic purposes. Pluripotent stem cells (PSCs), comprising embryonic stem cells, and induced pluripotent stem cells (iPSCs) derived from adults, have the potential to generate functional kidney cells and tissue. Studies in mouse and human PSCs have identified specific approaches to the addition of growth factors, including Wnt and fibroblast growth factor, that can induce PSC differentiation into cells with phenotypic characteristics of nephron progenitor populations with the capacity to form kidney-like structures. Although significant progress has been made, further studies are necessary to confirm the production of functional kidney cells and to promote their three-dimensional organization into bona fide kidney tissue. Human PSCs have been generated from patients with kidney diseases, including polycystic kidney disease, Alport syndrome, and Wilms tumor, and may be used to better understand phenotypic consequences of naturally occurring genetic mutations and to conduct "clinical trials in a dish". The capability to generate human kidney cells from PSCs has significant translational applications, including the bioengineering of functional kidney tissue, use in drug development to test compounds for efficacy and toxicity, and in vitro disease modeling.

  11. Triclosan Induces Thymic Stromal Lymphopoietin in Skin Promoting Th2 Allergic Responses.

    PubMed

    Marshall, Nikki B; Lukomska, Ewa; Long, Carrie M; Kashon, Michael L; Sharpnack, Douglas D; Nayak, Ajay P; Anderson, Katie L; Jean Meade, B; Anderson, Stacey E

    2015-09-01

    Triclosan is an antimicrobial chemical incorporated into many personal, medical and household products. Approximately, 75% of the U.S. population has detectable levels of triclosan in their urine, and although it is not typically considered a contact sensitizer, recent studies have begun to link triclosan exposure with augmented allergic disease. We examined the effects of dermal triclosan exposure on the skin and lymph nodes of mice and in a human skin model to identify mechanisms for augmenting allergic responses. Triclosan (0%-3%) was applied topically at 24-h intervals to the ear pinnae of OVA-sensitized BALB/c mice. Skin and draining lymph nodes were evaluated for cellular responses and cytokine expression over time. The effects of triclosan (0%-0.75%) on cytokine expression in a human skin tissue model were also examined. Exposure to triclosan increased the expression of TSLP, IL-1β, and TNF-α in the skin with concomitant decreases in IL-25, IL-33, and IL-1α. Similar changes in TSLP, IL1B, and IL33 expression occurred in human skin. Topical application of triclosan also increased draining lymph node cellularity consisting of activated CD86(+)GL-7(+) B cells, CD80(+)CD86(+) dendritic cells, GATA-3(+)OX-40(+)IL-4(+)IL-13(+) Th2 cells and IL-17 A(+) CD4 T cells. In vivo antibody blockade of TSLP reduced skin irritation, IL-1β expression, lymph node cellularity, and Th2 responses augmented by triclosan. Repeated dermal exposure to triclosan induces TSLP expression in skin tissue as a potential mechanism for augmenting allergic responses.

  12. An immunosuppressive murine leukaemia virus induces a Th1-->Th2 switch and abrogates the IgM antibody response to sheep erythrocytes by suppressing the production of IL-2.

    PubMed Central

    Faxvaag, A; Espevik, T; Dalen, A

    1995-01-01

    Many retroviruses have tropism for cells in the immune system and have a propensity to induce immunosuppression in the host. Some of the effects of retroviruses on immune cell function are thought to be mediated through cytokines. Friend ImmunoSuppressive virus-2 (FIS-2) is a low oncogenic murine leukaemia virus (MuLV) that induces lymphadenopathy and immunosuppression in NMRI mice. The role of T cell cytokines during the generation of a primary antibody response in healthy and FIS-2-infected mice was studied following the antibody response to sheep erythrocytes by an in vitro immunization (IVI) technique. In cultures from FIS-2-infected mice, the antibody response was reduced compared with cultures from uninfected mice and the production of the Th2 cytokines IL-4 and IL-6 was elevated, whereas the Th1 cytokines IL-2, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were reduced. The suppressed anti-sheep erythrocyte antibody response in cultures from mice infected with FIS-2 seemed to be caused by an insufficient production of IL-2, since addition of recombinant IL-2 stimulated the antibody response. This effect was also observed in cultures depleted of T cells, indicating a direct effect of IL-2 on B cells. A switch to a Th2 cell response and suppression of IL-2 production might play a central role in the immune cell dysfunction induced by FIS-2. PMID:8536362

  13. Methanol crossover in direct methanol fuel cell systems.

    SciTech Connect

    Pivovar, B. S.; Bender, G.; Davey, J. R.; Zelenay, P.

    2003-01-01

    Direct methanol fuel cells (DMFCs) are currently being investigated for a number of different applications from several milliwatts to near kilowatt size scales (cell phones, laptops, auxiliary power units, etc .). Because methanol has a very high energy density, over 6000 W hr/kg, a DMFC can possibly have greatly extended lifetimes compared to the batteries, doesn't present the storage problems associated with hydrogen fuel cells and can possibly operate more efficiently and cleanly than internal combustion engines.

  14. A Computer Model for Direct Carbonate Fuel Cells

    SciTech Connect

    Ding, J.; Patel, P.S.; Farooque, M.; Maru, H.C.

    1997-04-01

    A 3-D computer model, describing fluid flow, heat and mass transfer, and chemical and electrochemical reaction processes, has been developed for guiding the direct carbonate fuel cell (DFC) stack design. This model is able to analyze the direct internal reforming (DIR) as well as the integrated IIR (indirect internal reforming)-DIR designs. Reasonable agreements between computed and fuel cell tested results, such as flow variations, temperature distributions, cell potentials, and exhaust gas compositions as well as methane conversions, were obtained. Details of the model and comparisons of the modeling results with experimental DFC stack data are presented in the paper.

  15. Host Th1/Th2 immune response to Taenia solium cyst antigens in relation to cyst burden of neurocysticercosis.

    PubMed

    Tharmalingam, J; Prabhakar, A T; Gangadaran, P; Dorny, P; Vercruysse, J; Geldhof, P; Rajshekhar, V; Alexander, M; Oommen, A

    2016-10-01

    Neurocysticercosis (NCC), Taenia solium larval infection of the brain, is an important cause of acquired seizures in endemic countries, which relate to number, location and degenerating cysts in the brain. Multicyst infections are common in endemic countries although single-cyst infection prevails in India. Single-cyst infections in an endemic country suggest a role for host immunity limiting the infection. This study examined ex vivo CD4(+) T cells and in vitro Th1 and Th2 cytokine responses to T. solium cyst antigens of peripheral blood mononuclear cells of healthy subjects from endemic and nonendemic regions and of single- and multicyst-infected patients for association with cyst burden of NCC. T. solium cyst antigens elicited a Th1 cytokine response in healthy subjects of T. solium-endemic and T. solium-non-endemic regions and those with single-cyst infections and a Th2 cytokine response from subjects with multicyst neurocysticercosis. Multicyst neurocysticercosis subjects also exhibited low levels of effector memory CD4(+) T cells. Th1 cytokine response of T. solium exposure and low infectious loads may aid in limiting cyst number. Th2 cytokines and low effector T cells may enable multiple-cyst infections to establish and persist.

  16. Inhibition of caspase-8 activity promotes protective Th1- and Th2-mediated immunity to Leishmania major infection.

    PubMed

    Pereira-Manfro, Wânia F; Ribeiro-Gomes, Flávia L; Filardy, Alessandra Almeida; Vellozo, Natália S; Guillermo, Landi V C; Silva, Elisabeth M; Siegel, Richard M; Dosreis, George A; Lopes, Marcela F

    2014-02-01

    We investigated how apoptosis pathways mediated by death receptors and caspase-8 affect cytokine responses and immunity to Leishmania major parasites. Splenic CD4 T cells undergo activation-induced apoptosis, and blockade of FasL-Fas interaction increased IFN-γ and IL-4 cytokine responses to L. major antigens. To block death receptor-induced death, we used mice expressing a T cell-restricted transgene for vFLIP. Inhibition of caspase-8 activation in vFLIP mice enhanced Th1 and Th2 cytokine responses to L. major infection, even in the Th1-prone B6 background. We also observed increased NO production by splenocytes from vFLIP mice upon T cell activation. Despite an exacerbated Th2 response, vFLIP mice controlled better L. major infection, with reduced lesions and lower parasite loads compared with WT mice. Moreover, injection of anti-IL-4 mAb in infected vFLIP mice disrupted control of parasite infection. Therefore, blockade of caspase-8 activity in T cells improves immunity to L. major infection by promoting increased Th1 and Th2 responses.

  17. Direct cell-cell contact with the vascular niche maintains quiescent neural stem cells

    PubMed Central

    Ottone, Cristina; Krusche, Benjamin; Whitby, Ariadne; Clements, Melanie; Quadrato, Giorgia; Pitulescu, Mara E.; Adams, Ralf H.; Parrinello, Simona

    2014-01-01

    The vasculature is a prominent component of the subventricular zone neural stem cell niche. Although quiescent neural stem cells physically contact blood vessels at specialised endfeet, the significance of this interaction is not understood. In contrast, it is well established that vasculature-secreted soluble factors promote lineage progression of committed progenitors. Here we specifically investigated the role of cell-cell contact-dependent signalling in the vascular niche. Unexpectedly, we find that direct cell-cell interactions with endothelial cells enforces quiescence and promotes stem cell identity. Mechanistically, endothelial ephrinB2 and Jagged1 mediate these effects by suppressing cell-cycle entry downstream of mitogens and inducing stemness genes to jointly inhibit differentiation. In vivo, endothelial-specific ablation of either of the genes which encode these proteins, Efnb2 and Jag1 respectively, aberrantly activates quiescent stem cells, resulting in depletion. Thus, we identify the vasculature as a critical niche compartment for stem cell maintenance, furthering our understanding of how anchorage to the niche maintains stem cells within a pro-differentiative microenvironment. PMID:25283993

  18. Apoptosis by Direct Current Treatment in Tumor Cells and Tissues

    NASA Astrophysics Data System (ADS)

    Kim, Hongbae; Sim, Sungbo; Ahn, Saeyoung

    2003-10-01

    Electric field induces cell fusion, electroporation on biological cells, including apoptosis. Apoptosis is expressed in a series of natural enzymatic reactions for the natural elimination of unhealthy, genetically damaged, or otherwise aberrant cells that are not needed or not advantageous to the well-being of the organism. Its markers involve cell shrinkage, activation of intracellular caspase proteases, externalization of phosphatidylserine at the plasma membrane, and fragmentation of DNA. Direct electric fields using direct current have been exploited recently to investigate its effects on tumor cells and tissues, but the mechanism of direct electric fields has not been exhibited clearly other than by electroosmosis or pH changes. Direct electric field induces apoptosis in tumor cells cultured and tumor tissues as indicated by cell shrinkage, DNA fragmentation and tumor suppression. In our experiment that direct electric field was applied to tumor tissues via two needle electrodes inserted into tumor tissue 5mm at distance in parallel, pH changes resulted from electrochemical reaction, exhibiting about pH 9.0, 1.83, 2.0 in the vicinity of cathodic and anodic electrode, and at their mid-point, respectively. DNA fragmentation of tumor tissues destructed by direct electric field was analyzed by Tunel assay by ApopTag technology. As a result of this analysis, it showed that apoptosis in tumor tissue destructed was increased up to 59.1normal(control) tissues, showing 41.1, 31.1cathodic tissues. In vitro cell survival was exhibited that it was decreased with enhancing electric current intensity in the same condition of electrical charge 5C having different time applied. We will show results of apoptosis analyzed by flow cytometry in vitro.

  19. Extracellular matrix components direct porcine muscle stem cell behavior

    SciTech Connect

    Wilschut, Karlijn J.; Haagsman, Henk P.; Roelen, Bernard A.J.

    2010-02-01

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  20. Paxillin controls directional cell motility in response to physical cues.

    PubMed

    Sero, Julia E; German, Alexandra E; Mammoto, Akiko; Ingber, Donald E

    2012-01-01

    Physical cues from the extracellular environment that influence cell shape and directional migration are transduced into changes in cytoskeletal organization and biochemistry through integrin-based cell adhesions to extracellular matrix (ECM). Paxillin is a focal adhesion (FA) scaffold protein that mediates integrin anchorage to the cytoskeleton, and has been implicated in regulation of FA assembly and cell migration. To determine whether paxillin is involved in coupling mechanical distortion with directional movement, cell shape was physically constrained by culturing cells on square-shaped fibronectin-coated adhesive islands surrounded by non-adhesive barrier regions that were created with a microcontact printing technique. Square-shaped cells preferentially formed FAs and extended lamellipodia from their corner regions when stimulated with PDGF, and loss of paxillin resulted in loss of this polarized response. Selective expression of the N- and C-terminal domains of paxillin produced opposite, but complementary, effects on suppressing or promoting lamellipodia formation in different regions of square cells, which corresponded to directional motility defects in vitro. Paxillin loss or mutation was also shown to affect the formation of circular dorsal ruffles, and this corresponded to changes in cell invasive behavior in 3D. This commentary addresses the implications of these findings in terms of how a multifunctional FA scaffold protein can link physical cues to cell adhesion, protrusion and membrane trafficking so as to control directional migration in 2D and 3D. We also discuss how microengineered ECM islands and in vivo model systems can be used to further elucidate the functions of paxillin in directional migration.

  1. High specific power, direct methanol fuel cell stack

    DOEpatents

    Ramsey, John C.; Wilson, Mahlon S.

    2007-05-08

    The present invention is a fuel cell stack including at least one direct methanol fuel cell. A cathode manifold is used to convey ambient air to each fuel cell, and an anode manifold is used to convey liquid methanol fuel to each fuel cell. Tie-bolt penetrations and tie-bolts are spaced evenly around the perimeter to hold the fuel cell stack together. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet manifold with an integral flow restrictor to the outlet manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold. Located between the two plates is the fuel cell active region.

  2. Association of Th1 and Th2 cytokines with transient inflammatory reaction during lenalidomide plus dexamethasone therapy in multiple myeloma.

    PubMed

    Harada, Takeshi; Ozaki, Shuji; Oda, Asuka; Fujii, Shiro; Nakamura, Shingen; Miki, Hirokazu; Kagawa, Kumiko; Takeuchi, Kyoko; Matsumoto, Toshio; Abe, Masahiro

    2013-06-01

    Transient inflammatory reactions have been reported in a subpopulation of patients with multiple myeloma (MM) during lenalidomide (Len) plus dexamethasone (DEX) therapy. Here, we examined serum levels of Th1 (IL-2 and IFN-γ) and Th2 cytokines (IL-6 and TNF-α) in nine refractory or relapsed MM patients treated with Len plus low-dose DEX. Six patients showed elevation of C-reactive protein (CRP) after the initiation of therapy. In these patients, IFN-γ and IL-6 were also elevated in two and three patients, respectively. The remaining three patients showed no appreciable changes in CRP or these cytokines. Furthermore, Len enhanced the production of both Th1 and Th2 cytokines in normal peripheral blood mononuclear cells and in patient bone marrow mononuclear cells containing primary myeloma cells and lymphocytes. These results suggest that the modulation of the Th1 and Th2 cytokine production by Len may contribute to transient inflammatory reaction in MM patients.

  3. Toll Like Receptor 3 modulates immunopathology during a Schistosoma mansoni egg-driven Th2 response in the lung

    PubMed Central

    Joshi, Amrita D.; Schaller, Matthew; Lukacs, Nicholas W.; Kunkel, Steven L.; Hogaboam, Cory M.

    2010-01-01

    We examined the role of Toll Like Receptor 3 (TLR3) in Th2-driven pulmonary granulomatous disease, using wildtype (TLR3+/+) and TLR3 gene deficient (TLR3−/−) mice in a well-established model of S. mansoni egg induced pulmonary granuloma. The intravenous bolus injection of S. mansoni eggs into S. mansoni-sensitized TLR3+/+ mice was associated with an increase in TLR3 transcript expression in alveolar macrophages and ex vivo spleen and lung cultures at day 8 after egg injection. Lungs from TLR3−/− mice showed an increase in granuloma size, greater collagen deposition around the granuloma, and increased Th2 cytokine and chemokine levels compared with similarly sensitized and challenged TLR3+/+ mice. Macrophages from TLR3−/− mice exhibited a M2 phenotype characterized by increased arginase and CCL2 expression. Significantly greater numbers of CD4+CD25+ T cells were present in the lungs of TLR3−/− mice compared with TLR3+/+ mice at day 8 after egg embolization. Cells derived from granulomatous lung and lung draining lymph nodes of TLR3−/− mice released significantly higher levels of IL-17 levels relative to TLR3+/+ cells. Thus, our data suggest that TLR3 has a major regulatory role during a Th2-driven granulomatous response as its absence enhanced immunopathology. PMID:19009529

  4. Propagating Waves of Directionality and Coordination Orchestrate Collective Cell Migration

    PubMed Central

    Zaritsky, Assaf; Kaplan, Doron; Hecht, Inbal; Natan, Sari; Wolf, Lior; Gov, Nir S.; Ben-Jacob, Eshel; Tsarfaty, Ilan

    2014-01-01

    The ability of cells to coordinately migrate in groups is crucial to enable them to travel long distances during embryonic development, wound healing and tumorigenesis, but the fundamental mechanisms underlying intercellular coordination during collective cell migration remain elusive despite considerable research efforts. A novel analytical framework is introduced here to explicitly detect and quantify cell clusters that move coordinately in a monolayer. The analysis combines and associates vast amount of spatiotemporal data across multiple experiments into transparent quantitative measures to report the emergence of new modes of organized behavior during collective migration of tumor and epithelial cells in wound healing assays. First, we discovered the emergence of a wave of coordinated migration propagating backward from the wound front, which reflects formation of clusters of coordinately migrating cells that are generated further away from the wound edge and disintegrate close to the advancing front. This wave emerges in both normal and tumor cells, and is amplified by Met activation with hepatocyte growth factor/scatter factor. Second, Met activation was found to induce coinciding waves of cellular acceleration and stretching, which in turn trigger the emergence of a backward propagating wave of directional migration with about an hour phase lag. Assessments of the relations between the waves revealed that amplified coordinated migration is associated with the emergence of directional migration. Taken together, our data and simplified modeling-based assessments suggest that increased velocity leads to enhanced coordination: higher motility arises due to acceleration and stretching that seems to increase directionality by temporarily diminishing the velocity components orthogonal to the direction defined by the monolayer geometry. Spatial and temporal accumulation of directionality thus defines coordination. The findings offer new insight and suggest a basic

  5. Direct reprogramming of adult cells: avoiding the pluripotent state.

    PubMed

    Kelaini, Sophia; Cochrane, Amy; Margariti, Andriana

    2014-01-01

    The procedure of using mature, fully differentiated cells and inducing them toward other cell types while bypassing an intermediate pluripotent state is termed direct reprogramming. Avoiding the pluripotent stage during cellular conversions can be achieved either through ectopic expression of lineage-specific factors (transdifferentiation) or a direct reprogramming process that involves partial reprogramming toward the pluripotent stage. Latest advances in the field seek to alleviate concerns that include teratoma formation or retroviral usage when it comes to delivering reprogramming factors to cells. They also seek to improve efficacy and efficiency of cellular conversion, both in vitro and in vivo. The final products of this reprogramming approach could be then directly implemented in regenerative and personalized medicine.

  6. Chondrocytes Directly Transform into Bone Cells in Mandibular Condyle Growth

    PubMed Central

    Jing, Y.; Zhou, X.; Han, X.; Jing, J.; von der Mark, K.; Wang, J.; de Crombrugghe, B.; Hinton, R.J.; Feng, J.Q.

    2015-01-01

    For decades, it has been widely accepted that hypertrophic chondrocytes undergo apoptosis prior to endochondral bone formation. However, very recent studies in long bone suggest that chondrocytes can directly transform into bone cells. Our initial in vivo characterization of condylar hypertrophic chondrocytes revealed modest numbers of apoptotic cells but high levels of antiapoptotic Bcl-2 expression, some dividing cells, and clear alkaline phosphatase activity (early bone marker). Ex vivo culture of newborn condylar cartilage on a chick chorioallantoic membrane showed that after 5 d the cells on the periphery of the explants had begun to express Col1 (bone marker). The cartilage-specific cell lineage–tracing approach in triple mice containing Rosa 26tdTomato (tracing marker), 2.3 Col1GFP (bone cell marker), and aggrecan CreERT2 (onetime tamoxifen induced) or Col10-Cre (activated from E14.5 throughout adult stage) demonstrated the direct transformation of chondrocytes into bone cells in vivo. This transformation was initiated at the inferior portion of the condylar cartilage, in contrast to the initial ossification site in long bone, which is in the center. Quantitative data from the Col10-Cre compound mice showed that hypertrophic chondrocytes contributed to ~80% of bone cells in subchondral bone, ~70% in a somewhat more inferior region, and ~40% in the most inferior part of the condylar neck (n = 4, P < 0.01 for differences among regions). This multipronged approach clearly demonstrates that a majority of chondrocytes in the fibrocartilaginous condylar cartilage, similar to hyaline cartilage in long bones, directly transform into bone cells during endochondral bone formation. Moreover, ossification is initiated from the inferior portion of mandibular condylar cartilage with expansion in one direction. PMID:26341973

  7. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    SciTech Connect

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  8. Analysis of Serum Th1/Th2 Cytokine Levels in Patients with Acute Mumps Infection

    PubMed Central

    Malaiyan, Jeevan; Ramanan, Padmasani Venkat; Subramaniam, Dinesh; Menon, Thangam

    2016-01-01

    Background: The mumps virus is frequently the causative agent of parotitis. There has been no study on serum cytokine levels of acute mumps parotitis except for a few which document cytokine levels in cerebrospinal fluid of mumps meningitis. It is with this notion, our study aimed to find Th1/Th2 cytokine levels from patients with acute mumps parotitis. Materials and Methods: Concentrations of mumps-specific IgM, mumps, measles, rubella-specific IgG antibody, and Th1/Th2 cytokines, namely interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, and IL-10 were measured simultaneously in serum from 74 patients (42 pediatric and 32 adult cases), 40 healthy subjects (20 pediatric and 20 adults) and in the supernatant of peripheral blood mononuclear cells stimulated with mumps virus genotype C which served as the positive control. Statistical significance was analyzed between each group by means of Mann–Whitney U-test, Kruskal–Wallis test, and Spearman's rank correlation coefficient test. Results: IgM positivity confirmed acute infection in all 74 patients and of these 67 were vaccinated cases; however, very few of them (10/67) were positive for mumps IgG. We found that IFN-γ, IL-2, and IL-10 showed a statistically significant increase in both pediatric and adult patients with acute mumps infection when compared to healthy controls and values were comparable to the positive control. Conclusion: The Th1 cells play important roles during the acute phase of mumps parotitis. PMID:27293364

  9. Analysis of primary cilia in directional cell migration in fibroblasts.

    PubMed

    Christensen, Søren T; Veland, Iben R; Schwab, Albrecht; Cammer, Michael; Satir, Peter

    2013-01-01

    Early studies of migrating fibroblasts showed that primary cilia orient in front of the nucleus and point toward the leading edge. Recent work has shown that primary cilia coordinate a series of signaling pathways critical to fibroblast cell migration during development and in wound healing. In particular, platelet-derived growth factor receptor alpha (PDGFRα) is compartmentalized to the primary cilium to activate signaling pathways that regulate reorganization of the cytoskeleton required for lamellipodium formation and directional migration in the presence of a specific ligand gradient. We summarize selected methods in analyzing ciliary function in directional cell migration, including immunofluorescence microscopy, scratch assay, and chemotaxis assay by micropipette addition of PDGFRα ligands to cultures of fibroblasts. These methods should be useful not only in studying cell migration but also more generally in delineating response pathways in cells with primary cilia.

  10. Alkaline direct alcohol fuel cells using an anion exchange membrane

    NASA Astrophysics Data System (ADS)

    Matsuoka, Koji; Iriyama, Yasutoshi; Abe, Takeshi; Matsuoka, Masao; Ogumi, Zempachi

    Alkaline direct alcohol fuel cells using an OH-form anion exchange membrane and polyhydric alcohols were studied. A high open circuit voltage of ca. 800 mV was obtained for a cell using Pt-Ru/C (anode) and Pt/C (cathode) at 323 K, which was about 100-200 mV higher than that for a DMFC using Nafion ®. The maximum power densities were in the order of ethylene glycol > glycerol > methanol > erythritol > xylitol. Silver catalysts were used as a cathode catalyst to fabricate alkaline fuel cells, since silver catalyst is almost inactive in the oxidation of polyhydric alcohols. Alkaline direct ethylene glycol fuel cells using silver as a cathode catalyst gave excellent performance because higher concentrations of fuel could be supplied to the anode.

  11. Conceptual and methodological advances in cell-free directed evolution

    PubMed Central

    Dodevski, Igor; Markou, George C.; Sarkar, Casim A.

    2015-01-01

    Although cell-free directed evolution methods have been used to engineer proteins for nearly two decades, selections on more complex phenotypes have largely remained in the domain of cell-based engineering approaches. Here, we review recent conceptual advances that now enable in vitro display of multimeric proteins, integral membrane proteins, and proteins with an expanded amino acid repertoire. Additionally, we discuss methodological improvements that have enhanced the accessibility, efficiency, and robustness of cell-free approaches. Coupling these advances with the in vitro advantages of creating exceptionally large libraries and precisely controlling all experimental conditions, cell-free directed evolution is poised to contribute significantly to our understanding and engineering of more complex protein phenotypes. PMID:26093059

  12. Human embryonic stem cell derivation and directed differentiation.

    PubMed

    Trounson, A

    2005-01-01

    Human embryonic stem cells (hESCs) are produced from normal, chromosomally aneuploid and mutant human embryos, which are available from in vitro fertilisation (IVF) for infertility or preimplantation diagnosis. These hESC lines are an important resource for functional genomics, drug screening and eventually cell and gene therapy. The methods for deriving hESCs are well established and repeatable, and are relatively successful, with a ratio of 1:10 to 1:2 hESC lines established to embryos used. hESCs can be formed from morula and blastocyst-stage embryos and from isolated inner cell mass cell (ICM) clusters. The hESCs can be formed and maintained on mouse or human somatic cells in serum-free conditions, and for several passages in cell-free cultures. The hESCs can be transfected with DNA constructs. Their gene expression profiles are being described and immunological characteristics determined. They may be grown indefinitely in culture while maintaining their original karyotype but this must be confirmed from time to time. hESCs spontaneously differentiate in the absence of the appropriate cell feeder layer, when overgrown in culture and when isolated from the ESC colony. All three major embryonic lineages are produced in differentiating attachment cultures and in unattached embryoid bodies. Cell progenitors of interest can be identified by markers, expression of reporter genes and characteristic morphology, and the culture thereafter enriched for further culture to more mature cell types. The most advanced directed differentiation pathways have been developed for neural cells and cardiac muscle cells, but many other cell types including haematopoietic progenitors, endothelial cells, lung alveoli, keratinocytes, pigmented retinal epithelium, neural crest cells and motor neurones, hepatic progenitors and cells that have some markers of gut tissue and pancreatic cells have been produced. The prospects for regenerative medicine are significant and there is much

  13. Dynamic simulation of a direct carbonate fuel cell power plant

    SciTech Connect

    Ernest, J.B.; Ghezel-Ayagh, H.; Kush, A.K.

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  14. Enhanced methanol utilization in direct methanol fuel cell

    DOEpatents

    Ren, Xiaoming; Gottesfeld, Shimshon

    2001-10-02

    The fuel utilization of a direct methanol fuel cell is enhanced for improved cell efficiency. Distribution plates at the anode and cathode of the fuel cell are configured to distribute reactants vertically and laterally uniformly over a catalyzed membrane surface of the fuel cell. A conductive sheet between the anode distribution plate and the anodic membrane surface forms a mass transport barrier to the methanol fuel that is large relative to a mass transport barrier for a gaseous hydrogen fuel cell. In a preferred embodiment, the distribution plate is a perforated corrugated sheet. The mass transport barrier may be conveniently increased by increasing the thickness of an anode conductive sheet adjacent the membrane surface of the fuel cell.

  15. Impaired Memory in OT-II Transgenic Mice Is Associated with Decreased Adult Hippocampal Neurogenesis Possibly Induced by Alteration in Th2 Cytokine Levels

    PubMed Central

    Jeon, Seong Gak; Kim, Kyoung Ah; Chung, Hyunju; Choi, Junghyun; Song, Eun Ji; Han, Seung-Yun; Oh, Myung Sook; Park, Jong Hwan; Kim, Jin-il; Moon, Minho

    2016-01-01

    Recently, an increasing number of studies have focused on the effects of CD4+ T cell on cognitive function. However, the changes of Th2 cytokines in restricted CD4+ T cell receptor (TCR) repertoire model and their effects on the adult hippocampal neurogenesis and memory are not fully understood. Here, we investigated whether and how the mice with restricted CD4+ repertoire TCR exhibit learning and memory impairment by using OT-II mice. OT-II mice showed decreased adult neurogenesis in hippocampus and short- and long- term memory impairment. Moreover, Th2 cytokines in OT-II mice are significantly increased in peripheral organs and IL-4 is significantly increased in brain. Finally, IL-4 treatment significantly inhibited the proliferation of cultured adult rat hippocampal neural stem cells. Taken together, abnormal level of Th2 cytokines can lead memory dysfunction via impaired adult neurogenesis in OT-II transgenic. PMID:27432189

  16. Impaired Memory in OT-II Transgenic Mice Is Associated with Decreased Adult Hippocampal Neurogenesis Possibly Induced by Alteration in Th2 Cytokine Levels.

    PubMed

    Jeon, Seong Gak; Kim, Kyoung Ah; Chung, Hyunju; Choi, Junghyun; Song, Eun Ji; Han, Seung-Yun; Oh, Myung Sook; Park, Jong Hwan; Kim, Jin-Il; Moon, Minho

    2016-08-31

    Recently, an increasing number of studies have focused on the effects of CD4+ T cell on cognitive function. However, the changes of Th2 cytokines in restricted CD4+ T cell receptor (TCR) repertoire model and their effects on the adult hippocampal neurogenesis and memory are not fully understood. Here, we investigated whether and how the mice with restricted CD4+ repertoire TCR exhibit learning and memory impairment by using OT-II mice. OT-II mice showed decreased adult neurogenesis in hippocampus and short- and long- term memory impairment. Moreover, Th2 cytokines in OT-II mice are significantly increased in peripheral organs and IL-4 is significantly increased in brain. Finally, IL-4 treatment significantly inhibited the proliferation of cultured adult rat hippocampal neural stem cells. Taken together, abnormal level of Th2 cytokines can lead memory dysfunction via impaired adult neurogenesis in OT-II transgenic.

  17. Direct Effect of Zinc on Mitochondrial Apoptogenesis in Prostate Cells

    PubMed Central

    Feng, Pei; Li, Tie-Luo; Guan, Zhi-Xin; Franklin, Renty B.; Costello, Leslie C.

    2015-01-01

    BACKGROUND Prostate epithelial cells uniquely accumulate significantly higher levels of zinc than other mammalian cells. We previously showed that the accumulation of high intracellular zinc levels in specific prostate cells results in the induction of apoptosis and the inhibition of cell growth. The apoptotic effect is due to zinc induction of mitochondrial apoptogenesis. We now report additional studies that corroborate this effect of zinc and provide insight into the mechanism of this unique effect. METHODS The effect of exposure to physiological levels of zinc on apoptosis was determined for three human prostate cell lines (PC-3, BPH, and HPR-1). Zinc-induced apoptosis was identified by DNA fragmentation. The direct effect of zinc on isolated mitochondrial preparations from each cell line was determined. The mitochondrial release of cytochrome c was determined by Western blot. RESULTS Exposure to zinc induced apoptosis in PC-3 and BPH cells but not in HPR-1 cells. The zinc accumulation in PC-3 (4.3 ± 0.3) and BPH (2.8 ± 0.4) was higher than that in HPR-1 cells (1.8 ± 0.1). The apoptotic effect of zinc on PC-3 cells could be observed as early as 4–6 hr of zinc treatment, and this effect was not reversible. The exposure of isolated mitochondria from PC-3 and BPH cells to zinc resulted in the release of cytochrome c; but zinc had no effect on mitochondria from HPR-1 cells. CONCLUSIONS Exposure to zinc induces apoptosis in PC-3 and BPH cells, which accumulate high intracellular levels of zinc, but not in HPR-1 cells, which do not accumulate high levels of zinc. Once initiated, the induction of apoptosis is not reversed by the removal of zinc, i.e., it is an irreversible process. The apoptogenic effect is due to a direct effect of zinc on mitochondria that results in the release of cytochrome c. The cell specificity of zinc induction of apoptogenesis is dependent on the ability of the cells to accumulate high levels of intracellular zinc and on the ability of

  18. Materials and Manufacturing Challenges of Direct Methanol Fuel Cells

    DTIC Science & Technology

    2009-04-27

    SPSf. Figure 5 shows four basic polymers in which benzimidazole (BIm), amino- benzimidazole (ABIm), nitrobenzimidazole (NBIm), and perimidine (PImd...Membranes Based on Sulfonated Polyetheretherketone and Polysulfone Bearing Benzimidazole Side Groups for Fuel Cells,” Electrochemistry Communications...Bearing Benzimidazole Side Groups for Direct Methanol Fuel Cells,” Electrochemical and Solid State Letters, Vol. 10, 2007, p. B70-B73. [12] Fu, Y.-Z

  19. Microtopography and flow modulate the direction of endothelial cell migration.

    PubMed

    Uttayarat, P; Chen, M; Li, M; Allen, F D; Composto, R J; Lelkes, P I

    2008-02-01

    The migration of vascular endothelial cells under flow can be modulated by the addition of chemical or mechanical stimuli. The aim of this study was to investigate how topographic cues derived from a substrate containing three-dimensional microtopography interact with fluid shear stress in directing endothelial cell migration. Subconfluent bovine aortic endothelial cells were seeded on fibronectin-coated poly(dimethylsiloxane) substrates patterned with a combinatorial array of parallel and orthogonal microgrooves ranging from 2 to 5 microm in width at a constant depth of 1 microm. During a 4-h time-lapse observation in the absence of flow, the majority of the prealigned cells migrated parallel to the grooves with the distribution of their focal adhesions (FAs) depending on the groove width. No change in this migratory pattern was observed after the cells were exposed to moderate shear stress (13.5 dyn/cm(2)), irrespective of groove direction with respect to flow. After 4-h exposure to high shear stress (58 dyn/cm(2)) parallel to the grooves, the cells continued to migrate in the direction of both grooves and flow. By contrast, when microgrooves were oriented perpendicular to flow, most cells migrated orthogonal to the grooves and downstream with flow. Despite the change in the migration direction of the cells under high shear stress, most FAs and actin microfilaments maintained their original alignment parallel to the grooves, suggesting that topographic cues were more effective than those derived from shear stress in guiding the orientation of cytoskeletal and adhesion proteins during the initial exposure to flow.

  20. The planar cell polarity pathway directs parietal endoderm migration.

    PubMed

    LaMonica, Kristi; Bass, Maya; Grabel, Laura

    2009-06-01

    Parietal endoderm (PE) contributes to the yolk sac and is the first migratory cell type in the mammalian embryo. We can visualize PE migration in vitro using the F9 teratocarcinoma derived embryoid body outgrowth system and, show here that PE migration is directed by the non-canonical Wnt planar cell polarity (PCP) pathway via Rho/ROCK. Based on golgi apparatus localization and microtubule orientation, 68.6% of cells in control outgrowths are oriented in the direction of migration. Perturbation of Wnt signaling via sFRP treatment results in a loss of orientation coupled with an increase in cell migration. Inhibition of the PCP pathway at the level of Daam1 also results in a loss of cell orientation along with an increase in cell migration, as seen with sFRP treatment. Constitutively active Daam can inhibit the loss of orientation that occurs with sFRP treatment. We previously demonstrated that ROCK inhibition leads to an increase in cell migration, and we now show that these cells also lack oriented migration. Canonical Wnt signaling or the Rac arm of the PCP pathway does not appear to play a role in PE oriented migration. These data suggest the PCP pathway via Rho/ROCK modulates migration of PE.

  1. Directional control of lamellipodia extension by constraining cell shape and orienting cell tractional forces

    NASA Technical Reports Server (NTRS)

    Parker, Kevin Kit; Brock, Amy Lepre; Brangwynne, Cliff; Mannix, Robert J.; Wang, Ning; Ostuni, Emanuele; Geisse, Nicholas A.; Adams, Josephine C.; Whitesides, George M.; Ingber, Donald E.

    2002-01-01

    Directed cell migration is critical for tissue morphogenesis and wound healing, but the mechanism of directional control is poorly understood. Here we show that the direction in which cells extend their leading edge can be controlled by constraining cell shape using micrometer-sized extracellular matrix (ECM) islands. When cultured on square ECM islands in the presence of motility factors, cells preferentially extended lamellipodia, filopodia, and microspikes from their corners. Square cells reoriented their stress fibers and focal adhesions so that tractional forces were concentrated in these corner regions. When cell tension was dissipated, lamellipodia extension ceased. Mechanical interactions between cells and ECM that modulate cytoskeletal tension may therefore play a key role in the control of directional cell motility.

  2. Increased Fetal Thymocytes Apoptosis Contributes to Prenatal Nicotine Exposure-induced Th1/Th2 Imbalance in Male Offspring Mice

    PubMed Central

    Chen, Ting; Yan, You-e; Liu, Sha; Liu, Han-xiao; Yan, Hui-yi; Hou, Li-fang; Qu, Wen; Ping, Jie

    2016-01-01

    Nicotine, a definite risk factor during pregnancy, is an immunomodulator. This study was designed to investigate the effects of prenatal nicotine exposure (PNE) on the balance of Th1/Th2 in offspring, and further explore the developmental origin mechanisms from the perspective of fetal thymocytes apoptosis. Pregnant Balb/c mice were administered 1.5 mg/kg nicotine subcutaneously twice per day from gestational day (GD) 9 to GD18. Results showed that PNE could cause a Th2 shift in male offspring, manifested as increased ratio of IgG1/IgG2a, IL-4 production in serum, and IL-4/IFN-γ expression ratio in spleen. Increased apoptosis of total thymocytes and CD4SP and reduced cell proportion of CD4SP were found in PNE male offspring on postnatal day (PND) 14 and PND 49. In the fetuses, decreased body weight and organ index of fetal thymus, histological changes in fetal thymus, reduced CD4SP proportion and increased fetal thymocyte apoptosis were observed in nicotine group. The increased mRNA expression of genes involved in Fas-mediated apoptotic pathway and protein expression of Fas were also detected. In conclusion, PNE could cause a Th2 shift in male offspring mediated by reduced CD4+ T cells output, which may result from the increasing apoptosis of total thymocytes and CD4SP. PMID:27976742

  3. Graphene Oxide Attenuates Th2-Type Immune Responses, but Augments Airway Remodeling and Hyperresponsiveness in a Murine Model of Asthma

    PubMed Central

    2015-01-01

    Several lines of evidence indicate that exposure to nanoparticles (NPs) is able to modify airway immune responses, thus facilitating the development of respiratory diseases. Graphene oxide (GO) is a promising carbonaceous nanomaterial with unique physicochemical properties, envisioned for a multitude of medical and industrial applications. In this paper, we determined how exposure to GO modulates the allergic pulmonary response. Using a murine model of ovalbumin (OVA)-induced asthma, we revealed that GO, given at the sensitization stage, augmented airway hyperresponsiveness and airway remodeling in the form of goblet cell hyperplasia and smooth muscle hypertrophy. At the same time, the levels of the cytokines IL-4, IL-5, and IL-13 were reduced in broncho-alveolar lavage (BAL) fluid in GO-exposed mice. Exposure to GO during sensitization with OVA decreased eosinophil accumulation and increased recruitment of macrophages in BAL fluid. In line with the cytokine profiles, sensitization with OVA in the presence of GO stimulated the production of OVA-specific IgG2a and down-regulated the levels of IgE and IgG1. Moreover, exposure to GO increased the macrophage production of the mammalian chitinases, CHI3L1 and AMCase, whose expression is associated with asthma. Finally, molecular modeling has suggested that GO may directly interact with chitinase, affecting AMCase activity, which has been directly proven in our studies. Thus, these data show that GO exposure attenuates Th2 immune response in a model of OVA-induced asthma, but leads to potentiation of airway remodeling and hyperresponsiveness, with the induction of mammalian chitinases. PMID:24847914

  4. Bifunctional activation of a direct methanol fuel cell

    NASA Astrophysics Data System (ADS)

    Kulikovsky, A. A.; Schmitz, H.; Wippermann, K.; Mergel, J.; Fricke, B.; Sanders, T.; Sauer, D. U.

    We report a novel method for performance recovery of direct methanol fuel cells. Lowering of air flow rate below a critical value turns the cell into bifunctional regime, when the oxygen-rich part of the cell generates current while the rest part works in electrolysis mode (electrolytic domain). Upon restoring the normal (super-critical) air flow rate, the galvanic performance of the electrolytic domain increases. This recovery effect is presumably attributed to Pt surface cleaning on the cathode with the simultaneous increase in catalyst utilization on the anode.

  5. Direct patterning of mammalian cells in an ultrasonic heptagon stencil.

    PubMed

    Bernassau, A L; Gesellchen, F; Macpherson, P G A; Riehle, M; Cumming, D R S

    2012-06-01

    We describe the construction of a ultrasonic device suitable for micro patterning particles and cells for tissue engineering applications. The device is formed by seven transducers shaped into a heptagon cavity. By exciting two and three transducers simultaneously, lines or hexagonal shapes can be formed with beads and cells. Furthermore, phase control of the transducers allows shifting the standing waves and thus patterning at different positions on a surface in a controlled manner. The paper discusses direct patterning of mammalian cells by ultrasound "stencil".

  6. The production and directed differentiation of human embryonic stem cells.

    PubMed

    Trounson, Alan

    2006-04-01

    Human embryonic stem cells (hESCs) are being rapidly produced from chromosomally euploid, aneuploid, and mutant human embryos that are available from in vitro fertilization clinics treating patients for infertility or preimplantation genetic diagnosis. These hESC lines are an important resource for functional genomics, drug screening, and, perhaps eventually, cell and gene therapy. The methods for deriving hESCs are well established and repeatable and are relatively successful with a ratio of 1:10 to 1:2 new hESC lines produced from 4- to 8-d-old morula and blastocysts and from isolated inner cell mass cell clusters of human blastocysts. The hESCs can be formed and maintained on human somatic cells in humanized serum-free culture conditions and for several passages in cell-free culture systems. The hESCs can be transfected with DNA constructs. Their gene expression profiles are being described and immunological characteristics determined. They may be grown indefinitely in vitro while maintaining their original karyotype and epigenetic status, but this needs to be confirmed from time to time in long-term cultures. hESCs spontaneously differentiate in the absence of the appropriate cell feeder layer, when overgrown in culture and when isolated from the ESC colony. All three major embryonic lineages are produced in differentiating flat attachment cultures and unattached embryoid bodies. Cell progenitors of interest can be identified by markers, expression of reporter genes, and characteristic morphology, and the cells thereafter enriched for progenitor types and further culture to more mature cell types. Directed differentiation systems are well developed for ectodermal pathways that result in neural and glial cells and the mesendodermal pathway for cardiac muscle cells and many other cell types including hematopoietic progenitors and endothelial cells. Directed differentiation into endoderm has been more difficult to achieve, perhaps because of the lack of markers of

  7. A development of direct hydrazine/hydrogen peroxide fuel cell

    NASA Astrophysics Data System (ADS)

    Lao, Shao Jiang; Qin, Hai Ying; Ye, Li Qiang; Liu, Bin Hong; Li, Zhou Peng

    A direct hydrazine fuel cell using H 2O 2 as the oxidizer has been developed. The N 2H 4/H 2O 2 fuel cell is assembled by using Ni-Pt/C composite catalyst as the anode catalyst, Au/C as the cathode catalyst, and Nafion membrane as the electrolyte. Both anolyte and catholyte show significant influences on cell voltage and cell performance. The open-circuit voltage of the N 2H 4/H 2O 2 fuel cell reaches up to 1.75 V when using alkaline N 2H 4 solution as the anolyte and acidic H 2O 2 solution as the catholyte. A maximum power density of 1.02 W cm -2 has been achieved at operation temperature of 80 °C. The number of electrons exchanged in the H 2O 2 reduction reaction on Au/C catalyst is 2.

  8. Direct hydrogen fuel cell systems for hybrid vehicles

    NASA Astrophysics Data System (ADS)

    Ahluwalia, Rajesh K.; Wang, X.

    Hybridizing a fuel cell system with an energy storage system offers an opportunity to improve the fuel economy of the vehicle through regenerative braking and possibly to increase the specific power and decrease the cost of the combined energy conversion and storage systems. Even in a hybrid configuration it is advantageous to operate the fuel cell system in a load-following mode and use the power from the energy storage system when the fuel cell alone cannot meet the power demand. This paper discusses an approach for designing load-following fuel cell systems for hybrid vehicles and illustrates it by applying it to pressurized, direct hydrogen, polymer-electrolyte fuel cell (PEFC) systems for a mid-size family sedan. The vehicle level requirements relative to traction power, response time, start-up time and energy conversion efficiency are used to select the important parameters for the PEFC stack, air management system, heat rejection system and the water management system.

  9. Thermodynamic properties of direct methanol polymer electrolyte fuel cell

    NASA Astrophysics Data System (ADS)

    Seong, Ji Yun; Bae, Young Chan; Sun, Yang Kook

    A new semi-empirical model is established to describe the cell voltage of a direct methanol fuel cell (DMFC) as a function of current density. The model equation is validated experimental data over a wide range of a methanol concentration and temperatures. A number of existing models are semi-empirical. They, however, have a serious mathematical defect. When the current density, j, becomes zero, the equation should reduce to the open circuit voltage, E0. These models, however, do not meet the mathematical boundary condition. The proposed model focuses on very unfavorable conditions for the cell operation, i.e. low methanol solution concentrations and relatively low cell temperatures. A newly developed semi-empirical equation with reasonable boundary conditions includes the methanol crossover effect that plays a major role in determining the cell voltage of DMFC. Also, it contains methanol activity based on thermodynamic functions to represent methanol crossover effect.

  10. The contact allergen dinitrochlorobenzene (DNCB) and respiratory allergy in the Th2-prone Brown Norway rat.

    PubMed

    Kuper, C Frieke; Stierum, Rob H; Boorsma, Andre; Schijf, Marcel A; Prinsen, Menk; Bruijntjes, Joost P; Bloksma, Nanne; Arts, Josje H E

    2008-04-18

    All LMW respiratory allergens known to date can also induce skin allergy in test animals. The question here was if in turn skin allergens can induce allergy in the respiratory tract. Respiratory allergy was tested in Th2-prone Brown Norway (BN) rats by dermal sensitization with the contact allergen dinitrochlorobenzene (DNCB; 1%, day 0; 0.5%, day 7) and a head/nose-only inhalation challenge of 27mg/m3 of DNCB (15 min, day 21), using a protocol that successfully identified chemical respiratory allergens. Skin allergy to DNCB was examined in BN rats and Th1-prone Wistar rats in a local lymph node assay followed by a topical patch challenge of 0.1% DNCB. Sensitization of BN rats via the skin induced DNCB-specific IgG in serum, but not in all animals, and an increased number of CD4+ cells in the lung parenchyma. Subsequent inhalation challenge with DNCB did not provoke apneas or allergic inflammation (signs of respiratory allergy) in the BN rats. However, microarray analysis of mRNA isolated from the lung revealed upregulation of the genes for Ccl2 (MCP-1), Ccl4 (MIP-1beta), Ccl7 and Ccl17. Skin challenge induced considerably less skin irritation and allergic dermatitis in the BN rat than in the Wistar rat. In conclusion, the Th2-prone BN rat appeared less sensitive to DNCB than the Wistar rat; nevertheless, DNCB induced allergic inflammation in the skin of BN rats but even a relatively high challenge concentration did not induce allergy in the respiratory tract, although genes associated with allergy were upregulated in lung tissue.

  11. Transcriptomic-Wide Discovery of Direct and Indirect HuR RNA Targets in Activated CD4+ T Cells

    PubMed Central

    Techasintana, Patsharaporn; Davis, J. Wade; Gubin, Matthew M.; Magee, Joseph D.; Atasoy, Ulus

    2015-01-01

    Due to poor correlation between steady state mRNA levels and protein product, purely transcriptomic profiling methods may miss genes posttranscriptionally regulated by RNA binding proteins (RBPs) and microRNAs (miRNAs). RNA immunoprecipitation (RIP) methods developed to identify in vivo targets of RBPs have greatly elucidated those mRNAs which may be regulated via transcript stability and translation. The RBP HuR (ELAVL1) and family members are major stabilizers of mRNA. Many labs have identified HuR mRNA targets; however, many of these analyses have been performed in cell lines and oftentimes are not independent biological replicates. Little is known about how HuR target mRNAs behave in conditional knock-out models. In the present work, we performed HuR RIP-Seq and RNA-Seq to investigate HuR direct and indirect targets using a novel conditional knock-out model of HuR genetic ablation during CD4+ T activation and Th2 differentiation. Using independent biological replicates, we generated a high coverage RIP-Seq data set (>160 million reads) that was analyzed using bioinformatics methods specifically designed to find direct mRNA targets in RIP-Seq data. Simultaneously, another set of independent biological replicates were sequenced by RNA-Seq (>425 million reads) to identify indirect HuR targets. These direct and indirect targets were combined to determine canonical pathways in CD4+ T cell activation and differentiation for which HuR plays an important role. We show that HuR may regulate genes in multiple canonical pathways involved in T cell activation especially the CD28 family signaling pathway. These data provide insights into potential HuR-regulated genes during T cell activation and immune mechanisms. PMID:26162078

  12. Retnla (Relma/Fizz1) suppresses helminth-induced Th2-Type immunity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Retnla (Resistin-like molecule alpha/FIZZ1) is induced during Th2 cytokine immune responses. Using Retnla deficient (-/-) mice and three helminth models, we show that Retnla functions as a negative regulator of Th2 responses. Pulmonary granuloma formation induced by the eggs of the helminth parasite...

  13. T1/ST2 promotes T helper 2 cell activation and polyfunctionality in bronchopulmonary mycosis.

    PubMed

    Piehler, D; Grahnert, A; Eschke, M; Richter, T; Köhler, G; Stenzel, W; Alber, G

    2013-03-01

    Interleukin (IL)-33 enhances T helper (Th)2 immunity via its receptor T1/ST2. Infection with the yeast-like pathogen Cryptococcus neoformans is usually controlled by a Th1-mediated immune response. The mechanisms responsible for nonprotective Th2 immunity leading to allergic inflammation in pulmonary cryptococcosis are still not fully understood. Using a murine pulmonary model of C. neoformans infection, we report that T1/ST2 expression correlates with the intensity of Th2 activation, as demonstrated by the expression of CD25 and CD44 and downregulation of CD62L. Antigen-specific T1/ST2(+) Th cells are the primary source of the Th2 cytokines IL-5 and IL-13 as compared with wild-type T1/ST2(-) Th cells or Th cells from T1/ST2(-/-) mice. In addition, T1/ST2(+) Th cells almost exclusively contain bi- and trifunctional Th2 cytokine-producing Th cells compared with T1/ST2(-) Th cells or Th cells from T1/ST2(-/-) mice. Finally, T1/ST2-driven Th2 development resulted in defective pulmonary fungal control. These data demonstrate that T1/ST2 directs Th2 cell activation and polyfunctionality in allergic bronchopulmonary mycosis.

  14. Picroside II Attenuates Airway Inflammation by Downregulating the Transcription Factor GATA3 and Th2-Related Cytokines in a Mouse Model of HDM-Induced Allergic Asthma

    PubMed Central

    Kim, Jin seok; Lee, Jae-Won; Park, Hyun Ah; Ryu, Hyung Won; Lee, Su Ui; Hwang, Kwang Woo; Yun, Won-Kee; Kim, Hyoung-Chin; Ahn, Kyung-Seop; Oh, Sei-Ryang

    2016-01-01

    Picroside II isolated from Pseudolysimachion rotundum var. subintegrum has been used as traditional medicine to treat inflammatory diseases. In this study, we assessed whether picroside II has inhibitory effects on airway inflammation in a mouse model of house dust mite (HDM)-induced asthma. In the HDM-induced asthmatic model, picroside II significantly reduced inflammatory cell counts in the bronchoalveolar lavage fluid (BALF), the levels of total immunoglobulin (Ig) E and HDM-specific IgE and IgG1 in serum, airway inflammation, and mucus hypersecretion in the lung tissues. ELISA analysis showed that picroside II down-regulated the levels of Th2-related cytokines (including IL-4, IL-5, and IL-13) and asthma-related mediators, but it up-regulated Th1-related cytokine, IFNγ in BALF. Picroside II also inhibited the expression of Th2 type cytokine genes and the transcription factor GATA3 in the lung tissues of HDM-induced mice. Finally, we demonstrated that picroside II significantly decreased the expression of GATA3 and Th2 cytokines in developing Th2 cells, consistent with in vivo results. Taken together, these results indicate that picroside II has protective effects on allergic asthma by reducing GATA3 expression and Th2 cytokine bias. PMID:27870920

  15. The danger signal, extracellular ATP, is a sensor for an airborne allergen and triggers IL-33 release and innate Th2-type responses.

    PubMed

    Kouzaki, Hideaki; Iijima, Koji; Kobayashi, Takao; O'Grady, Scott M; Kita, Hirohito

    2011-04-01

    The molecular mechanisms underlying the initiation of innate and adaptive proallergic Th2-type responses in the airways are not well understood. IL-33 is a new member of the IL-1 family of molecules that is implicated in Th2-type responses. Airway exposure of naive mice to a common environmental aeroallergen, the fungus Alternaria alternata, induces rapid release of IL-33 into the airway lumen, followed by innate Th2-type responses. Biologically active IL-33 is constitutively stored in the nuclei of human airway epithelial cells. Exposing these epithelial cells to A. alternata releases IL-33 extracellularly in vitro. Allergen exposure also induces acute extracellular accumulation of a danger signal, ATP; autocrine ATP sustains increases in intracellular Ca(2+) concentration and releases IL-33 through activation of P2 purinergic receptors. Pharmacological inhibitors of purinergic receptors or deficiency in the P2Y2 gene abrogate IL-33 release and Th2-type responses in the Alternaria-induced airway inflammation model in naive mice, emphasizing the essential roles for ATP and the P2Y(2) receptor. Thus, ATP and purinergic signaling in the respiratory epithelium are critical sensors for airway exposure to airborne allergens, and they may provide novel opportunities to dampen the hypersensitivity response in Th2-type airway diseases such as asthma.

  16. Direct Visualization of De novo Lipogenesis in Single Living Cells

    NASA Astrophysics Data System (ADS)

    Li, Junjie; Cheng, Ji-Xin

    2014-10-01

    Increased de novo lipogenesis is being increasingly recognized as a hallmark of cancer. Despite recent advances in fluorescence microscopy, autoradiography and mass spectrometry, direct observation of de novo lipogenesis in living systems remains to be challenging. Here, by coupling stimulated Raman scattering (SRS) microscopy with isotope labeled glucose, we were able to trace the dynamic metabolism of glucose in single living cells with high spatial-temporal resolution. As the first direct visualization, we observed that glucose was largely utilized for lipid synthesis in pancreatic cancer cells, which occurs at a much lower rate in immortalized normal pancreatic epithelial cells. By inhibition of glycolysis and fatty acid synthase (FAS), the key enzyme for fatty acid synthesis, we confirmed the deuterium labeled lipids in cancer cells were from de novo lipid synthesis. Interestingly, we also found that prostate cancer cells exhibit relatively lower level of de novo lipogenesis, but higher fatty acid uptake compared to pancreatic cancer cells. Together, our results demonstrate a valuable tool to study dynamic lipid metabolism in cancer and other disorders.

  17. Recent advances in high-performance direct methanol fuel cells

    SciTech Connect

    Narayanan, S.R.; Chun, W.; Valdez, T.I.

    1996-12-31

    Direct methanol fuel cells for portable power applications have been advanced significantly under DARPA- and ARO-sponsored programs over the last five years. A liquid-feed direct methanol fuel cell developed under these programs, employs a proton exchange membrane as electrolyte and operates on aqueous solutions of methanol with air or oxygen as the oxidant. Power densities as high as 320 mW/cm{sup 2} have been demonstrated. Demonstration of five-cell stack based on the liquid-feed concept have been successfully performed by Giner Inc. and the Jet Propulsion Laboratory. Over 2000 hours of life-testing have been completed on these stacks. These fuel cells have been also been demonstrated by USC to operate on alternate fuels such as trimethoxymethane, dimethoxymethane and trioxane. Reduction in the parasitic loss of fuel across the fuel cell, a phenomenon termed as {open_quotes}fuel crossover{close_quotes} has been achieved using polymer membranes developed at USC. As a result efficiencies as high as 40% is considered attainable with this type of fuel cell. The state-of-development has reached a point where it is now been actively considered for stationary, portable and transportation applications. The research and development issues have been the subject of several previous articles and the present article is an attempt to summarize the key advances in this technology.

  18. Direct effect of bevacizumab on glioblastoma cell lines in vitro.

    PubMed

    Simon, Thomas; Coquerel, Bérénice; Petit, Alexandre; Kassim, Yusra; Demange, Elise; Le Cerf, Didier; Perrot, Valérie; Vannier, Jean-Pierre

    2014-12-01

    Bevacizumab is a humanized monoclonal antibody directed against the pro-angiogenic factor vascular and endothelial growth factor-A (VEGF-A) used in the treatment of glioblastomas. Although most patients respond initially to this treatment, studies have shown that glioblastomas eventually recur. Several non-mutually exclusive theories based on the anti-angiogenic effect of bevacizumab have been proposed to explain these mechanisms of resistance. In this report, we studied whether bevacizumab can act directly on malignant glioblastoma cells. We observe changes in the expression profiles of components of the VEGF/VEGF-R pathway and in the response to a VEGF-A stimulus following bevacizumab treatment. In addition, we show that bevacizumab itself acts on glioblastoma cells by activating the Akt and Erks survival signaling pathways. Bevacizumab also enhances proliferation and invasiveness of glioblastoma cells in hyaluronic acid hydrogel. We propose that the paradoxical effect of bevacizumab on glioblastoma cells could be due to changes in the VEGF-A-dependent autocrine loop as well as in the intracellular survival pathways, leading to the enhancement of tumor aggressiveness. Investigation of how bevacizumab interacts with glioblastoma cells and the resulting downstream signaling pathways will help targeting populations of resistant glioblastoma cells.

  19. Long-lasting complete regression of established mouse tumors by counteracting Th2 inflammation

    PubMed Central

    Dai, Min; Wei, Huafeng; Yip, Yuen Yee; Feng, Qinghua; He, Kecheng; Popov, Viorica; Hellstrom, Ingegerd; Hellstrom, Karl Erik

    2013-01-01

    Mice with intraperitoneal ID8 ovarian carcinoma or subcutaneous SW1 melanoma were injected with monoclonal antibodies (mAbs) to CD137+PD-1+CTLA4 7-15 days following tumor initiation. Survival of mice with ID8 tumors tripled and >40% of mice with SW1 tumors remain healthy >150 days after later treatment and are probably cured. Therapeutic efficacy was associated with a systemic immune response with memory and antigen specificity and required CD4+ cells and involved CD8+ cells and NK cells to a less extent. The 3 mAb combination significantly decreased CD19+ cells at tumor sites, increased IFNγ and TNFα producing CD4+ and CD8+ T cells and mature CD86+ DC, and it increased the ratios of effector CD4+ and CD8+ T cells to CD4+Foxp3+ regulatory T cells and to CD11b+Gr-1+ myeloid suppressor cells. This is consistent with shifting the tumor microenvironment from an immunosuppressive Th2 to an immunostimulatory Th1 type and is further supported by PCR data. Adding an anti-CD19 mAb to the 3 mAb combination in the SW1 model further increased therapeutic efficacy. Data from ongoing experiments show that intratumoral injection of a combination of mAbs to CD137+PD-1+CLA4+CD19 can induce complete regression and dramatically prolong survival also in the TC1 carcinoma and B16 melanoma models, suggesting that the approach has general validity. PMID:23603859

  20. Cell-Substrate Interactions Feedback to Direct Cell Migration along or against Morphological Polarization

    PubMed Central

    Kumar, Girish; Ho, Chia-Chi; Co, Carlos C.

    2015-01-01

    In response to external stimuli, cells polarize morphologically into teardrop shapes prior to moving in the direction of their blunt leading edge through lamellipodia extension and retraction of the rear tip. This textbook description of cell migration implies that the initial polarization sets the direction of cell migration. Using microfabrication techniques to control cell morphologies and the direction of migration without gradients, we demonstrate that after polarization, lamelipodia extension and attachment can feedback to change and even reverse the initial morphological polarization. Cells do indeed migrate faster in the direction of their morphologically polarization. However, feedback from subsequent lamellipodia extension and attachment can be so powerful as to induce cells to reverse and migrate against their initial polarization, albeit at a slower speed. Constitutively active mutants of RhoA show that RhoA stimulates cell motility when cells are guided either along or against their initial polarization. Cdc42 activation and inhibition, which results in loss of directional motility during chemotaxis, only reduces the speed of migration without altering the directionality of migration on the micropatterns. These results reveal significant differences between substrate directed cell migration and that induced by chemotactic gradients. PMID:26186588

  1. Multifactorial Optimizations for Directing Endothelial Fate from Stem Cells

    PubMed Central

    Madfis, Nicole; Wong, Lian; Zamora, Jose; White, Nicholas; Reyes, Samuel; Burns, Andrew B.; Gopinathan, Ajay

    2016-01-01

    Embryonic stem cells (ESC) and induced pluripotent stem (iPS) cells are attractive in vitro models of vascular development, therapeutic angiogenesis, and tissue engineering. However, distinct ESC and iPS cell lines respond differentially to the same microenvironmental factors. Developing improved/optimized differentiation methodologies tailored/applicable in a number of distinct iPS and ESC lines remains a challenge in the field. Currently published methods for deriving endothelial cells (EC) robustly generate high numbers of endothlelial progenitor cells (EPC) within a week, but their maturation to definitive EC is much more difficult, taking up to 2 months and requiring additional purification. Therefore, we set out to examine combinations/levels of putative EC induction factors—utilizing our stage-specific chemically-defined derivation methodology in 4 ESC lines including: kinetics, cell seeding density, matrix signaling, as well as medium treatment with vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF). The results indicate that temporal development in both early and late stages is the most significant factor generating the desired cells. The generation of early Flk-1+/KDR+ vascular progenitor cells (VPC) from pluripotent ESC is directed predominantly by high cell seeding density and matrix signaling from fibronectin, while VEGF supplementation was NOT statistically significant in more than one cell line, especially with fibronectin matrix which sequesters autocrine VEGF production by the differentiating stem cells. Although some groups have shown that the GSK3-kinase inhibitor (CHIR) can facilitate EPC fate, it hindered the generation of KDR+ cells in our preoptimized medium formulations. The methods summarized here significantly increased the production of mature vascular endothelial (VE)-cadherin+ EC, with up to 93% and 57% purity from mouse and human ESC, respectively, before VE-cadherin+ EC purification. PMID:27907001

  2. The changes in the T helper 1 (Th1) and T helper 2 (Th2) cytokine balance during HIV-1 infection are indicative of an allergic response to viral proteins that may be reversed by Th2 cytokine inhibitors and immune response modifiers--a review and hypothesis.

    PubMed

    Becker, Yechiel

    2004-01-01

    The HIV-1 infection in humans induces an early cellular immune response to react to the viral proteins with a cytotoxic T cell (CTL) response that fails to inhibit virus replication and the spread of the virus. It became evident that the progression of the disease causes chronic changes to the immune system of which a gradual increase in IgE antibodies is one of its features. When the HIV-1 epidemic began, the relation between the gradual increase in IgE content and AIDS was not understood, but later it became a marker for disease prognosis. The advances in the knowledge on T helper 1 (Th1) and T helper 2 (Th2) cells revealed that Th1 cells produce cytokines that stimulate the proliferation of CTLs. Th2 cells produce cytokines that are responsible for the activation of the humoral immune response in healthy people. Studies on both Th1 and Th2 cytokine synthesis revealed an aberration in HIV-1 infected people. Clerici and Shearer presented a hypothesis (1993) whereby Th1 cell activity declines and Th2 activity increases (the Th1 --> Th2 switch hypothesis) in HIV-1 infected people. In fact, experiments concerning this hypothesis ultimately supported the premise that the switch involves a critical change in the cytokine balance, which leads to the contraction of AIDS. However, the research community must still discern why such a Th1 --> Th2 switch takes place in infected people and how it can be reversed. The present review points to the fact that a similar Th1 --> Th2 switch constitutes the response of allergic people to environmental allergens. HIV-1 patients and allergic people that are exposed to allergens respond with an increased synthesis of Th2 cytokines and IgE, together with a decrease in Th1 cytokines. The studies on allergen-induced Th2 cells revealed that the Th2 cytokine IL-4 induces B cells to synthesize IgE, and cytokine IL-5 is the inducer of eosinophilia, just as in HIV-1 infection. The difference between the HIV-1 infection and allergies is the

  3. DIRECTED DIFFERENTIATION OF EMBRYONIC STEM CELLS INTO BLADDER TISSUE

    PubMed Central

    Oottamasathien, Siam; Wang, YongQing; Williams, Karin; Franco, Omar E.; Wills, Marcia L.; Thomas, John C.; Saba, Katrina; Sharif-Afshar, Ali-Reza; Makari, John H.; Bhowmick, Neil A; DeMarco, Romano T.; Hipkens, Susan; Magnuson, Mark; Brock, John W.; Hayward, Simon W.; Pope, John C.; Matusik, Robert J.

    2007-01-01

    Manipulatable models of bladder development which interrogate specific pathways are badly needed. Such models will allow a systematic investigation of the multitude of pathologies which result from developmental defects of the urinary bladder. In the present communication, we describe a model in which mouse embryonic stem (ES) cells are directed to differentiate to form bladder tissue by specific interactions with fetal bladder mesenchyme. This model allows us to visualize the various stages in the differentiation of urothelium from ES cells, including the commitment to an endodermal cell lineage, with the temporal profile characterized by examining the induction of specific endodermal transcription factors (Foxa1 and Foxa2). In addition, final functional urothelial differentiation was characterized by examining uroplakin expression. It is well established that ES cells will spontaneously develop teratomas when grown within immunocompromised mouse hosts. We determined the specific mesenchymal to ES cell ratios necessary to dictate organ-specific differentiation while completely suppressing teratomatous growth. Embryonic mesenchyme is well established as an inductive tissue which dictates organ-specific programming of epithelial tissues. The present study demonstrates that embryonic bladder mesenchyme can also steer ES cells towards developing specific endodermal derived urothelium. These approaches allow us to capture specific stages of stem cell differentiation and to better define stem cell hierarchies. PMID:17289017

  4. Mesenchymal Stem Cells Induce Directional Migration of Invasive Breast Cancer Cells through TGF-β

    PubMed Central

    McAndrews, Kathleen M.; McGrail, Daniel J.; Ravikumar, Nithin; Dawson, Michelle R.

    2015-01-01

    Mesenchymal stem cells (MSCs) are recruited to the tumor microenvironment and influence tumor progression; however, how MSCs induce the invasion of cancer cells is not completely understood. Here, we used a 3D coculture model to determine how MSCs affect the migration of invasive breast cancer cells. Coculture with MSCs increases the elongation, directional migration, and traction generation of breast cancer cells. MSC-induced directional migration directly correlates with traction generation and is mediated by transforming growth factor β (TGF-β) and the migratory proteins rho-associated kinase, focal adhesion kinase, and matrix metalloproteinases. Treatment with MSC conditioned media or recombinant TGF-β1 elicits a similar migration response to coculture. Taken together, this work suggests TGF-β is secreted by MSCs, leading to force-dependent directional migration of invasive breast cancer cells. These pathways may be potential targets for blocking cancer cell invasion and subsequent metastasis. PMID:26585689

  5. Single passive direct methanol fuel cell supplied with pure methanol

    NASA Astrophysics Data System (ADS)

    Feng, Ligang; Zhang, Jing; Cai, Weiwei; Liang, Liang; Xing, Wei; Liu, Changpeng

    2011-03-01

    A new single passive direct methanol fuel cell (DMFC) supplied with pure methanol is designed, assembled and tested using a pervaporation membrane (PM) to control the methanol transport. The effect of the PM size on the fuel cell performances and the constant current discharge of the fuel cell with one-fueling are studied. The results show that the fuel cell with PM 9 cm2 can yield a maximum power density of about 21 mW cm-2, and a stable performances at a discharge current of 100 mA can last about 45 h. Compared with DMFC supplied with 3 M methanol solution, the energy density provided by this new DMFC has increased about 6 times.

  6. Process-Induced Cell Injury in Laser Direct Writing of Human Colon Cancer Cells.

    PubMed

    Lin, Yafu; Huang, Guohui; Huang, Yong; Tzeng, Tzuen-Rong J; Chrisey, Douglas B

    2010-03-19

    Matrix-assisted pulsed-laser evaporation direct-write has emerged as a promising technique for biological construct fabrication. The posttransfer cell viability in matrix-assisted pulsed-laser evaporation direct-write depends on various operating conditions such as the applied laser fluence. To date, the effects of operating conditions such as laser fluence, direct-writing height, and cell density on the posttransfer cell viability have not been well elucidated. This study investigates the effects of operating conditions on the posttransfer cell viability in laser direct writing of human colon cancer HT-29 cells. It has been observed that (1) the HT-29 cell viability decreases from 95% to 78% as the laser fluence increases from 258 to 1482 mJ/cm(2), and the posttransfer cell proliferation capacity does not vary significantly as the laser fluence changes; (2) the direct-writing height does not have noticeable effect on the posttransfer cell viability under low laser fluences (258 and 869 mJ/cm(2)). However, a larger height (such as 29.3 mm) led to an almost 8% viability improvement compared with that of 16.6 mm under a high laser fluence (1482 mJ/cm(2)); and (3) the posttransfer cell viability is not dependent on the cell density for a range from 1 × 10(6) to 1 × 10(7) cells/mL.

  7. Trioxane: A Fuel For Direct-Oxidation Fuel Cells

    NASA Technical Reports Server (NTRS)

    Olah, George A.; Prakash, Surya G.; Narayanan, Sekharipuram R.; Vamos, Eugene; Surampudi, Subbarao

    1995-01-01

    Trioxane identified as high-energy, nontoxic, solid substitute for formaldehyde as water-soluble fuel for use in direct-oxidation fuel cells. Found to undergo facile electrochemical oxidation to water and carbon dioxide at platinum and platinum-alloy electrodes in liquid-feed-type fuel cells that contain acid electrolytes or solid proton-exchange membrane electrolytes. Exhibits less crossover than do such conventional fuels as methanol and formaldehyde. Being solid at ambient temperature, trioxane offers significant advantages in handling and transportation. Synthesized from natural gas with relative ease.

  8. Wire mesh current collectors for passive direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Shrivastava, Naveen K.; Thombre, Shashikant B.; Motghare, Ramani V.

    2014-12-01

    This paper examines the feasibility of the stainless steel wire mesh as current collector in the passive direct methanol fuel cell (DMFCs-W). A novel single cell fixture is designed and fabricated. The cell performance is evaluated and compared with five different wire mesh current collectors. The supporting plates are optimized for every mesh. The performance of DMFCs-W is compared with the conventional passive DMFC which uses perforated metal plate as current collector (DMFC-P). The polarization tests and electrochemical impedance spectroscopy are performed to investigate the different aspects of the cell performance. The results reveal that the DMFCs-W yield better performance than the DMFC-P. Also, more uniform fuel distribution at catalyst layer and higher cell temperature is achieved with wire mesh current collectors. It is found that the wire mesh geometry has significant effect on the cell performance and the mesh made of relatively thick wires gives better cell performance. This study identifies the stainless steel wire mesh as promising material to be used as current collector and potential substitute to the perforated plate current collectors in the passive DMFC.

  9. Direct Visualization of DNA Replication Dynamics in Zebrafish Cells.

    PubMed

    Kuriya, Kenji; Higashiyama, Eriko; Avşar-Ban, Eriko; Tamaru, Yutaka; Ogata, Shin; Takebayashi, Shin-ichiro; Ogata, Masato; Okumura, Katsuzumi

    2015-12-01

    Spatiotemporal regulation of DNA replication in the S-phase nucleus has been extensively studied in mammalian cells because it is tightly coupled with the regulation of other nuclear processes such as transcription. However, little is known about the replication dynamics in nonmammalian cells. Here, we analyzed the DNA replication processes of zebrafish (Danio rerio) cells through the direct visualization of replicating DNA in the nucleus and on DNA fiber molecules isolated from the nucleus. We found that zebrafish chromosomal DNA at the nuclear interior was replicated first, followed by replication of DNA at the nuclear periphery, which is reminiscent of the spatiotemporal regulation of mammalian DNA replication. However, the relative duration of interior DNA replication in zebrafish cells was longer compared to mammalian cells, possibly reflecting zebrafish-specific genomic organization. The rate of replication fork progression and ori-to-ori distance measured by the DNA combing technique were ∼ 1.4 kb/min and 100 kb, respectively, which are comparable to those in mammalian cells. To our knowledge, this is a first report that measures replication dynamics in zebrafish cells.

  10. Direct Cytoskeleton Forces Cause Membrane Softening in Red Blood Cells

    PubMed Central

    Rodríguez-García, Ruddi; López-Montero, Iván; Mell, Michael; Egea, Gustavo; Gov, Nir S.; Monroy, Francisco

    2015-01-01

    Erythrocytes are flexible cells specialized in the systemic transport of oxygen in vertebrates. This physiological function is connected to their outstanding ability to deform in passing through narrow capillaries. In recent years, there has been an influx of experimental evidence of enhanced cell-shape fluctuations related to metabolically driven activity of the erythroid membrane skeleton. However, no direct observation of the active cytoskeleton forces has yet been reported to our knowledge. Here, we show experimental evidence of the presence of temporally correlated forces superposed over the thermal fluctuations of the erythrocyte membrane. These forces are ATP-dependent and drive enhanced flickering motions in human erythrocytes. Theoretical analyses provide support for a direct force exerted on the membrane by the cytoskeleton nodes as pulses of well-defined average duration. In addition, such metabolically regulated active forces cause global membrane softening, a mechanical attribute related to the functional erythroid deformability. PMID:26083919

  11. Direct methanol feed fuel cell with reduced catalyst loading

    NASA Technical Reports Server (NTRS)

    Kindler, Andrew (Inventor)

    1999-01-01

    Improvements to direct feed methanol fuel cells include new protocols for component formation. Catalyst-water repellent material is applied in formation of electrodes and sintered before application of ionomer. A membrane used in formation of an electrode assembly is specially pre-treated to improve bonding between catalyst and membrane. The improved electrode and the pre-treated membrane are assembled into a membrane electrode assembly.

  12. In vivo kinetics of transduced cells in peripheral T cell-directed gene therapy: role of CD8+ cells in improved immunological function in an adenosine deaminase (ADA)-SCID patient.

    PubMed

    Kawamura, N; Ariga, T; Ohtsu, M; Kobayashi, I; Yamada, M; Tame, A; Furuta, H; Okano, M; Egashira, M; Niikawa, N; Kobayashi, K; Sakiyama, Y

    1999-08-15

    We previously reported successful peripheral T cell-directed gene therapy in a boy with adenosine deaminase (ADA)-SCID. In the present study, to better understand the reconstitutive effect of this gene therapy on his immunological system, we investigated the in vivo kinetics and functional subsets of T cells in PBL. Apparent immunological improvements were obtained after infusion of transduced cells at more than 4 x 108 cells/kg/therapy/3 mo. Frequency of ADAcDNA-integrated cells in PBL, ADA activity in PBL and clinical improvement showed good correlation, even though CD8+ cells gradually became predominant in PBL. On the basis that polyethylene glycol (PEG)-ADA was maintained at the same dosage as before gene therapy, we consider that his immunological improvement resulted from the gene therapy itself. Most CD3+ cells in PBL after gene therapy expressed TCRalphabeta. Analysis of TCR repertoire based on TCR V region usage revealed no expansion of limited clones in his PBL. The T cell subset cells CD8+CDw60+ and CD8+CD27+CD45RA-, which are reported to provide substantial help to B cells, were maintained throughout the gene therapy. Furthermore, his reconstituted peripheral T cells helped normal B cells to produce substantial IgG in vitro. Expression of both Th1- and Th2-type cytokine genes was induced in his reconstituted T cells at the same comparably high level as in normal subjects. Collectively, these results provide evidence of persistent and distinct functions of transduced cells in this patient's PBL after gene therapy.

  13. Experimental Design to Evaluate Directed Adaptive Mutation in Mammalian Cells

    PubMed Central

    Chiaro, Christopher R; May, Tobias

    2014-01-01

    Background We describe the experimental design for a methodological approach to determine whether directed adaptive mutation occurs in mammalian cells. Identification of directed adaptive mutation would have profound practical significance for a wide variety of biomedical problems, including disease development and resistance to treatment. In adaptive mutation, the genetic or epigenetic change is not random; instead, the presence and type of selection influences the frequency and character of the mutation event. Adaptive mutation can contribute to the evolution of microbial pathogenesis, cancer, and drug resistance, and may become a focus of novel therapeutic interventions. Objective Our experimental approach was designed to distinguish between 3 types of mutation: (1) random mutations that are independent of selective pressure, (2) undirected adaptive mutations that arise when selective pressure induces a general increase in the mutation rate, and (3) directed adaptive mutations that arise when selective pressure induces targeted mutations that specifically influence the adaptive response. The purpose of this report is to introduce an experimental design and describe limited pilot experiment data (not to describe a complete set of experiments); hence, it is an early report. Methods An experimental design based on immortalization of mouse embryonic fibroblast cells is presented that links clonal cell growth to reversal of an inactivating polyadenylation site mutation. Thus, cells exhibit growth only in the presence of both the countermutation and an inducing agent (doxycycline). The type and frequency of mutation in the presence or absence of doxycycline will be evaluated. Additional experimental approaches would determine whether the cells exhibit a generalized increase in mutation rate and/or whether the cells show altered expression of error-prone DNA polymerases or of mismatch repair proteins. Results We performed the initial stages of characterizing our system

  14. Angiotensin II directly impairs adipogenic differentiation of human preadipose cells.

    PubMed

    Palominos, Marisol M; Dünner, Natalia H; Wabitsch, Martin; Rojas, Cecilia V

    2015-10-01

    Angiotensin II reduces adipogenic differentiation of preadipose cells present in the stroma-vascular fraction of human adipose tissue, which also includes several cell types. Because of the ability of non-adipose lineage cells in the stroma-vascular fraction to respond to angiotensin II, it is not possible to unequivocally ascribe the anti-adipogenic response to a direct effect of this hormone on preadipose cells. Therefore, we used the human Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte cell strain to investigate the consequences of angiotensin II treatment on adipogenic differentiation under serum-free conditions, by assessing expression of typical adipocyte markers perilipin and fatty acid-binding protein 4 (FABP4), at the transcript and protein level. Reverse transcription-polymerase chain reaction showed that perilipin and FABP4 transcripts were, respectively, reduced to 0.33 ± 0.07 (P < 0.05) and 0.41 ± 0.19-fold (P < 0.05) in SGBS cells induced to adipogenic differentiation in the presence of angiotensin II. Western Blot analysis corroborated reduction of the corresponding proteins to 0.23 ± 0.21 (P < 0.01) and 0.46 ± 0.30-fold (P < 0.01) the respective controls without angiotensin II. Angiotensin II also impaired morphological changes associated with early adipogenesis. Hence, we demonstrated that angiotensin II is able to directly reduce adipogenic differentiation of SGBS preadipose cells.

  15. Cell-directed-assembly: Directing the formation of nano/bio interfaces and architectures with living cells

    PubMed Central

    Baca, Helen K.; Carnes, Eric C.; Ashley, Carlee E.; Lopez, DeAnna M.; Douthit, Cynthia; Karlin, Shelly; Brinker, C. Jeffrey

    2011-01-01

    Background The desire to immobilize, encapsulate, or entrap viable cells for use in a variety of applications has been explored for decades. Traditionally, the approach is to immobilize cells to utilize a specific functionality of the cell in the system. Scope of Review This review describes our recent discovery that living cells can organize extended nanostructures and nano-objects to create a highly biocompatible nano//bio interface [1]. Major Conclusions We find that short chain phospholipids direct the formation of thin film silica mesophases during evaporation-induced self-assembly (EISA) [2], and that the introduction of cells alter the self-assembly pathway. Cells organize an ordered lipid-membrane that forms a coherent interface with the silica mesophase that is unique in that it withstands drying - yet it maintains accessibility to molecules introduced into the 3D silica host. Cell viability is preserved in the absence of buffer, making these constructs useful as standalone cell-based sensors. In response to hyperosmotic stress, the cells release water, creating a pH gradient which is maintained within the nanostructured host and serves to localize lipids, proteins, plasmids, lipidized nanocrystals, and other components at the cellular surface. This active organization of the bio/nano interface can be accomplished during ink-jet printing or selective wetting - processes allowing patterning of cellular arrays - and even spatially-defined genetic modification. General Significance Recent advances in the understanding of nanotechnology and cell biology encourage the pursuit of more complex endeavors where the dynamic interactions of the cell and host material act symbiotically to obtain new, useful functions. PMID:20933574

  16. Porous silicon-based direct hydrogen sulphide fuel cells.

    PubMed

    Dzhafarov, T D; Yuksel, S Aydin

    2011-10-01

    In this paper, the use of Au/porous silicon/Silicon Schottky type structure, as a direct hydrogen sulphide fuel cell is demonstrated. The porous silicon filled with hydrochlorid acid was developed as a proton conduction membrane. The Au/Porous Silicon/Silicon cells were fabricated by first creating the porous silicon layer in single-crystalline Si using the anodic etching under illumination and then deposition Au catalyst layer onto the porous silicon. Using 80 mM H2S solution as fuel the open circuit voltage of 0.4 V was obtained and maximum power density of 30 W/m2 at room temperature was achieved. These results demonstrate that the Au/Porous Silicon/Silicon direct hydrogen sulphide fuel cell which uses H2S:dH2O solution as fuel and operates at room temperature can be considered as the most promising type of low cost fuel cell for small power-supply units.

  17. LPS promotes Th2 dependent sensitisation leading to anaphylaxis in a Pru p 3 mouse model

    PubMed Central

    Rodriguez, Maria J.; Aranda, Ana; Fernandez, Tahia D.; Cubells-Baeza, Nuria; Torres, Maria J.; Gomez, Francisca; Palomares, Francisca; Perkins, James R.; Rojo, Javier; Diaz-Perales, Araceli; Mayorga, Cristobalina

    2017-01-01

    Pru p 3 is the major peach allergen in the Mediterranean area. It frequently elicits severe reactions, limiting its study in humans, raising the need for animal models to investigate the immunological mechanisms involved. However, no anaphylaxis model exists for Pru p 3. We aimed to develop a model of peach anaphylaxis by sensitising mice with Pru p 3 in combination with lipopolysaccharide (LPS) as an adjuvant. Four groups of mice were sensitised intranasally: untreated; treated with Pru p 3; treated with LPS; treated with Pru p 3 + LPS. After sensitisation mice were intraperitoneally challenged with Pru p 3 and in vivo and in vitro parameters were evaluated. Only mice in the Pru p 3 + LPS group showed anaphylaxis symptoms, including a decrease in temperature. Determination of in vitro parameters showed a Th2 response with an increase of Pru p 3-specific IgE and IgG1. Moreover, at the cellular level, we found increased levels of IgE and IgG1 secreting Pru p 3-specific cells and a proliferative CD4+ T-cell response. These results demonstrate that Pru p 3-specific anaphylaxis can be generated after nasal sensitisation to Pru p 3 in combination with LPS. This is a promising model for evaluating food allergy immunotherapies. PMID:28084419

  18. Direct carbonate fuel cell power plant operating with logistic fuels

    SciTech Connect

    Abens, S.G.; Steinfeld, G.

    1997-12-31

    In response to the US Department of Defense need for power generators which operate with logistic fuels, Energy Research Corporation and its subcontractors, Haldor Topsoe and Fluor Daniel, have conducted design studies and subscale equipment tests toward the development of fuel cell power plants with multifuel capability. A principal objective of this work was the development of a fixed-base carbonate fuel cell power plant design which can utilize both natural gas and military logistic fuels DF-2 and JP-8. To verify ERC`s technical approach, a 32 kW brassboard logistic fuel preprocessing system was assembled and operated with a Direct Carbonate Fuel Cell (DFC) stack. The project was conducted as part of DARPA`s Fuel Cell Power Plant Initiative Program for the development of dual use fuel cell power plants. The logistic fuel preprocessor consisted of a hydrodesulfurization plant which supplied desulfurized feed to an adiabatic prereformer. The methane-rich product gas provides fuel cell performance similar to that with natural gas. A preliminary design of a 3MW multifuel power plant prepared with input from the 32kW brassboard test confirmed that the thermal efficiency of a DFC power plant is nearly as high with logistic fuel (57%) as it is with natural gas (58%).

  19. Direct chromosome-length haplotyping by single-cell sequencing.

    PubMed

    Porubský, David; Sanders, Ashley D; van Wietmarschen, Niek; Falconer, Ester; Hills, Mark; Spierings, Diana C J; Bevova, Marianna R; Guryev, Victor; Lansdorp, Peter M

    2016-11-01

    Haplotypes are fundamental to fully characterize the diploid genome of an individual, yet methods to directly chart the unique genetic makeup of each parental chromosome are lacking. Here we introduce single-cell DNA template strand sequencing (Strand-seq) as a novel approach to phasing diploid genomes along the entire length of all chromosomes. We demonstrate this by building a complete haplotype for a HapMap individual (NA12878) at high accuracy (concordance 99.3%), without using generational information or statistical inference. By use of this approach, we mapped all meiotic recombination events in a family trio with high resolution (median range ∼14 kb) and phased larger structural variants like deletions, indels, and balanced rearrangements like inversions. Lastly, the single-cell resolution of Strand-seq allowed us to observe loss of heterozygosity regions in a small number of cells, a significant advantage for studies of heterogeneous cell populations, such as cancer cells. We conclude that Strand-seq is a unique and powerful approach to completely phase individual genomes and map inheritance patterns in families, while preserving haplotype differences between single cells.

  20. Direct Observation of Nanoparticle-Cancer Cell Nucleus Interactions

    PubMed Central

    Dam, Duncan Hieu M.; Lee, Jung Heon; Sisco, Patrick N.; Co, Dick T.; Zhang, Ming; Wasielewski, Michael R.; Odom, Teri W.

    2012-01-01

    We report the direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported to the nucleus and induced major changes to the nuclear phenotype via nuclear envelope invaginations near the site of the construct. The number of local deformations could be increased by ultra-fast, light-triggered release of the aptamers from the surface of the gold nanostars. Cancer cells with more nuclear envelope folding showed increased caspase 3 and 7 activity (apoptosis) as well as decreased cell viability. This newly revealed correlation between drug-induced changes in nuclear phenotype and increased therapeutic efficacy could provide new insight for nuclear-targeted cancer therapy. PMID:22424173

  1. Liquid Tin Anode Direct Coal Fuel Cell Final Program Report

    SciTech Connect

    Tao, Thomas

    2012-01-26

    This SBIR program will result in improved LTA cell technology which is the fundamental building block of the Direct Coal ECL concept. As described below, ECL can make enormous efficiency and cost contributions to utility scale coal power. This program will improve LTA cells for small scale power generation. As described in the Commercialization section, there are important intermediate military and commercial markets for LTA generators that will provide an important bridge to the coal power application. The specific technical information from this program relating to YSZ electrolyte durability will be broadly applicable SOFC developers working on coal based SOFC generally. This is an area about which very little is currently known and will be critical for successfully applying fuel cells to coal power generation.

  2. Catalytic polymeric electrodes for direct borohydride fuel cells

    NASA Astrophysics Data System (ADS)

    Bayatsarmadi, Bita; Peters, Alice; Talemi, Pejman

    2016-08-01

    The direct borohydride fuel cell (DBFC) is a new class of fuel cells that produces non-toxic by-products and has a potential for a high voltage and high energy density. A major challenge in developing efficient DBFCs is the development of an efficient, stable, and economic catalyst for the oxidation of borohydride. In this paper, we report the use of conducting polymer Poly(3,4-ethylenedioxythiophene) (PEDOT) as electrocatalysts in DBFC. PEDOT electrodes prepared by vacuum phase polymerization exhibited electrocatalytic behavior towards oxidation of borohydride and reduction of hydrogen peroxide. Spectroscopic analysis of samples showed that PEDOT can act as an interface for electron transfer from borohydride ions. Comparing the polarization curves of DBFCs with PEDOT coated on graphite electrodes and cells with bare graphite electrodes, demonstrated higher voltage, maximum power density, and stability.

  3. Low contaminant formic acid fuel for direct liquid fuel cell

    DOEpatents

    Masel, Richard I.; Zhu, Yimin; Kahn, Zakia; Man, Malcolm

    2009-11-17

    A low contaminant formic acid fuel is especially suited toward use in a direct organic liquid fuel cell. A fuel of the invention provides high power output that is maintained for a substantial time and the fuel is substantially non-flammable. Specific contaminants and contaminant levels have been identified as being deleterious to the performance of a formic acid fuel in a fuel cell, and embodiments of the invention provide low contaminant fuels that have improved performance compared to known commercial bulk grade and commercial purified grade formic acid fuels. Preferred embodiment fuels (and fuel cells containing such fuels) including low levels of a combination of key contaminants, including acetic acid, methyl formate, and methanol.

  4. Direct observation of nanoparticle-cancer cell nucleus interactions.

    PubMed

    Dam, Duncan Hieu M; Lee, Jung Heon; Sisco, Patrick N; Co, Dick T; Zhang, Ming; Wasielewski, Michael R; Odom, Teri W

    2012-04-24

    We report the direct visualization of interactions between drug-loaded nanoparticles and the cancer cell nucleus. Nanoconstructs composed of nucleolin-specific aptamers and gold nanostars were actively transported to the nucleus and induced major changes to the nuclear phenotype via nuclear envelope invaginations near the site of the construct. The number of local deformations could be increased by ultrafast, light-triggered release of the aptamers from the surface of the gold nanostars. Cancer cells with more nuclear envelope folding showed increased caspase 3 and 7 activity (apoptosis) as well as decreased cell viability. This newly revealed correlation between drug-induced changes in nuclear phenotype and increased therapeutic efficacy could provide new insight for nuclear-targeted cancer therapy.

  5. Engineered microtopographies and surface chemistries direct cell attachment and function

    NASA Astrophysics Data System (ADS)

    Magin, Chelsea Marie

    topographically modified surface (R2=0.82). Functionalized PEGDMA hydrogels significantly reduced attachment and attachment strength of Navicula and C. marina. These hydrogels also reduced attachment of zoospores of Ulva compared to PDMSe. Attachment of Ulva to microtopographies in PDMSe and PEGDMA-co-HEMA negatively correlated with ERIII*Re (R2 = 0.94 and R2 = 0.99, respectively). Incorporating a surface energy term into this equation created a correlation between the attachment densities of cells from two evolutionarily diverse groups on substrates of two surface chemistries with an equation that describes the various microtopographies and surface chemistries in terms of surface energy (R2 = 0.80). The current Attachment Model can now be used to design engineered antifouling surface microtopographies and chemistries that inhibit the attachment of organisms from three evoluntionarily diverse groups. Hydrogels based on PEGDMA were also chosen as a substratum material for mammalian cell culture. Capturing endothelial progenitor cells (EPCs) and inducing differentiation into the endothelial cell (EC) phenotype is the ideal way to re-endothelialize a small-diameter vascular graft. Substratum elasticity has been reported to direct stem cell differentiation into specific lineages. Functionalized PEGDMA hydrogels provided good compliance, high fidelity of topographic features and sites for surface modification with biomolecules. Fibronectin grafting and topography both increased EC attachment. This combination of adjustable elasticity, surface chemistry and topography has the potential to promote the capture and differentiation of EPCs into a confluent EC monolayer. Engineered microtopographies replicated in PDMSe directed elongation and alignment of human coronary artery endothelial cells (HCAECs) and human coronary artery smooth muscle cells (HCASMCs) compared to smooth surfaces. Engineered cellular micro-environments were created with specific surface energies defined by chemistry

  6. RNA Directed Modulation of Phenotypic Plasticity in Human Cells

    PubMed Central

    Burdach, Jon; Morris, Kevin V.

    2016-01-01

    Natural selective processes have been known to drive phenotypic plasticity, which is the emergence of different phenotypes from one genome following environmental stimulation. Long non-coding RNAs (lncRNAs) have been observed to modulate transcriptional and epigenetic states of genes in human cells. We surmised that lncRNAs are governors of phenotypic plasticity and drive natural selective processes through epigenetic modulation of gene expression. Using heat shocked human cells as a model we find several differentially expressed transcripts with the top candidates being lncRNAs derived from retro-elements. One particular retro-element derived transcripts, Retro-EIF2S2, was found to be abundantly over-expressed in heat shocked cells. Over-expression of Retro-EIF2S2 significantly enhanced cell viability and modulated a predisposition for an adherent cellular phenotype upon heat shock. Mechanistically, we find that this retro-element derived transcript interacts directly with a network of proteins including 40S ribosomal protein S30 (FAU), Eukaryotic translation initiation factor 5A (EIF5A), and Ubiquitin-60S ribosomal protein L40 (UBA52) to affect protein modulated cell adhesion pathways. We find one motif in Retro-EIF2S2 that exhibits binding to FAU and modulates phenotypic cell transitions from adherent to suspension states. The observations presented here suggest that retroviral derived transcripts actively modulate phenotypic plasticity in human cells in response to environmental selective pressures and suggest that natural selection may play out through the action of retro-elements in human cells. PMID:27082860

  7. RNA Directed Modulation of Phenotypic Plasticity in Human Cells.

    PubMed

    Trakman, Laura; Hewson, Chris; Burdach, Jon; Morris, Kevin V

    2016-01-01

    Natural selective processes have been known to drive phenotypic plasticity, which is the emergence of different phenotypes from one genome following environmental stimulation. Long non-coding RNAs (lncRNAs) have been observed to modulate transcriptional and epigenetic states of genes in human cells. We surmised that lncRNAs are governors of phenotypic plasticity and drive natural selective processes through epigenetic modulation of gene expression. Using heat shocked human cells as a model we find several differentially expressed transcripts with the top candidates being lncRNAs derived from retro-elements. One particular retro-element derived transcripts, Retro-EIF2S2, was found to be abundantly over-expressed in heat shocked cells. Over-expression of Retro-EIF2S2 significantly enhanced cell viability and modulated a predisposition for an adherent cellular phenotype upon heat shock. Mechanistically, we find that this retro-element derived transcript interacts directly with a network of proteins including 40S ribosomal protein S30 (FAU), Eukaryotic translation initiation factor 5A (EIF5A), and Ubiquitin-60S ribosomal protein L40 (UBA52) to affect protein modulated cell adhesion pathways. We find one motif in Retro-EIF2S2 that exhibits binding to FAU and modulates phenotypic cell transitions from adherent to suspension states. The observations presented here suggest that retroviral derived transcripts actively modulate phenotypic plasticity in human cells in response to environmental selective pressures and suggest that natural selection may play out through the action of retro-elements in human cells.

  8. Efficient direct ZnO/CIS solar cells

    SciTech Connect

    Olsen, L.C.; William Addis, F.; Lei, W.; Li, J.

    1996-01-01

    This paper describes investigations of CIS solar cells with ZnO window layers deposited by MOCVD. These studies have been conducted with graded absorber CIS substrates obtained from Siemens Solar. Cell fabrication involves surface preparation of the Siemens substrate, growth of 200 to 400 A of undoped ZnO by MOCVD, deposition of a highly conducting ZnO top contact layer and deposition of a Ni/Ag collector grid. MOCVD growth of ZnO is accomplished in a SPIRE 500XT reactor by reacting a zinc adduct and tetrahydrofuran. Processing development has been conducted by forming test cells on ZnO/CIS structures by depositing thin, transparent Al contacts 2.8 mm in diameter on top of the ZnO window layer to serve as contacts. Several cells have been completed with a total area efficiency {ge}11.0{percent}, with the best result being 11.3{percent}. The best active area efficiency is approximately 12{percent}. Other topics discussed include current-voltage characteristics of direct ZnO/CIS cells. {copyright} {ital 1996 American Institute of Physics.}

  9. Low Crossover Polymer Electrolyte Membranes for Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Prakash, G. K. Surya; Smart, Marshall; Atti, Anthony R.; Olah, George A.; Narayanan, S. R.; Valdez, T.; Surampudi, S.

    1996-01-01

    Direct Methanol Fuel Cells (DMFC's) using polymer electrolyte membranes are promising power sources for portable and vehicular applications. State of the art technology using Nafion(R) 117 membranes (Dupont) are limited by high methanol permeability and cost, resulting in reduced fuel cell efficiencies and impractical commercialization. Therefore, much research in the fuel cell field is focused on the preparation and testing of low crossover and cost efficient polymer electrolyte membranes. The University of Southern California in cooperation with the Jet Propulsion Laboratory is focused on development of such materials. Interpenetrating polymer networks are an effective method used to blend polymer systems without forming chemical links. They provide the ability to modify physical and chemical properties of polymers by optimizing blend compositions. We have developed a novel interpenetrating polymer network based on poly (vinyl - difluoride)/cross-linked polystyrenesulfonic acid polymer composites (PVDF PSSA). Sulfonation of polystyrene accounts for protonic conductivity while the non-polar, PVDF backbone provides structural integrity in addition to methanol rejection. Precursor materials were prepared and analyzed to characterize membrane crystallinity, stability and degree of interpenetration. USC JPL PVDF-PSSA membranes were also characterized to determine methanol permeability, protonic conductivity and sulfur distribution. Membranes were fabricated into membrane electrode assemblies (MEA) and tested for single cell performance. Tests include cell performance over a wide range of temperatures (20 C - 90 C) and cathode conditions (ambient Air/O2). Methanol crossover values are measured in situ using an in-line CO2 analyzer.

  10. Direct borohydride fuel cell using Ni-based composite anodes

    NASA Astrophysics Data System (ADS)

    Ma, Jia; Sahai, Yogeshwar; Buchheit, Rudolph G.

    In this study, nickel-based composite anode catalysts consisting of Ni with either Pd on carbon or Pt on carbon (the ratio of Ni:Pd or Ni:Pt being 25:1) were prepared for use in direct borohydride fuel cells (DBFCs). Cathode catalysts used were 1 mg cm -2 Pt/C or Pd electrodeposited on activated carbon cloth. The oxidants were oxygen, oxygen in air, or acidified hydrogen peroxide. Alkaline solution of sodium borohydride was used as fuel in the cell. High power performance has been achieved by DBFC using non-precious metal, Ni-based composite anodes with relatively low anodic loading (e.g., 270 mW cm -2 for NaBH 4/O 2 fuel cell at 60 °C, 665 mW cm -2 for NaBH 4/H 2O 2 fuel cell at 60 °C). Effects of temperature, oxidant, and anode catalyst loading on the DBFC performance were investigated. The cell was operated for about 100 h and its performance stability was recorded.

  11. Deterministic direct reprogramming of somatic cells to pluripotency.

    PubMed

    Rais, Yoach; Zviran, Asaf; Geula, Shay; Gafni, Ohad; Chomsky, Elad; Viukov, Sergey; Mansour, Abed AlFatah; Caspi, Inbal; Krupalnik, Vladislav; Zerbib, Mirie; Maza, Itay; Mor, Nofar; Baran, Dror; Weinberger, Leehee; Jaitin, Diego A; Lara-Astiaso, David; Blecher-Gonen, Ronnie; Shipony, Zohar; Mukamel, Zohar; Hagai, Tzachi; Gilad, Shlomit; Amann-Zalcenstein, Daniela; Tanay, Amos; Amit, Ido; Novershtern, Noa; Hanna, Jacob H

    2013-10-03

    Somatic cells can be inefficiently and stochastically reprogrammed into induced pluripotent stem (iPS) cells by exogenous expression of Oct4 (also called Pou5f1), Sox2, Klf4 and Myc (hereafter referred to as OSKM). The nature of the predominant rate-limiting barrier(s) preventing the majority of cells to successfully and synchronously reprogram remains to be defined. Here we show that depleting Mbd3, a core member of the Mbd3/NuRD (nucleosome remodelling and deacetylation) repressor complex, together with OSKM transduction and reprogramming in naive pluripotency promoting conditions, result in deterministic and synchronized iPS cell reprogramming (near 100% efficiency within seven days from mouse and human cells). Our findings uncover a dichotomous molecular function for the reprogramming factors, serving to reactivate endogenous pluripotency networks while simultaneously directly recruiting the Mbd3/NuRD repressor complex that potently restrains the reactivation of OSKM downstream target genes. Subsequently, the latter interactions, which are largely depleted during early pre-implantation development in vivo, lead to a stochastic and protracted reprogramming trajectory towards pluripotency in vitro. The deterministic reprogramming approach devised here offers a novel platform for the dissection of molecular dynamics leading to establishing pluripotency at unprecedented flexibility and resolution.

  12. T Follicular Helper Cell Plasticity Shapes Pathogenic T Helper 2 Cell-Mediated Immunity to Inhaled House Dust Mite.

    PubMed

    Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E; Spolski, Rosanne; Leonard, Warren J; León, Beatriz

    2016-02-16

    Exposure to environmental antigens, such as house dust mite (HDM), often leads to T helper 2 (Th2) cell-driven allergic responses. However, the mechanisms underlying the development of these responses are incompletely understood. We found that the initial exposure to HDM did not lead to Th2 cell development but instead promoted the formation of interleukin-4 (IL-4)-committed T follicular helper (Tfh) cells. Following challenge exposure to HDM, Tfh cells differentiated into IL-4 and IL-13 double-producing Th2 cells that accumulated in the lung and recruited eosinophils. B cells were required to expand IL-4-committed Tfh cells during the sensitization phase, but did not directly contribute to disease. Impairment of Tfh cell responses during the sensitization phase or Tfh cell depletion prevented Th2 cell-mediated responses following challenge. Thus, our data demonstrate that Tfh cells are precursors of HDM-specific Th2 cells and reveal an unexpected role of B cells and Tfh cells in the pathogenesis of allergic asthma.

  13. Manipulation of neutrophil-like HL-60 cells for the study of directed cell migration.

    PubMed

    Millius, Arthur; Weiner, Orion D

    2010-01-01

    Many cells undergo directed cell migration in response to external cues in a process known as chemotaxis. This ability is essential for many single-celled organisms to hunt and mate, the development of multicellular organisms, and the functioning of the immune system. Because of their relative ease of manipulation and their robust chemotactic abilities, the neutrophil-like cell line (HL-60) has been a powerful system to analyze directed cell migration. In this chapter, we describe the maintenance and transient transfection of HL-60 cells and explain how to analyze their behavior with two standard chemotactic assays (micropipette and EZ-TAXIS). Finally, we demonstrate how to fix and stain the actin cytoskeleton of polarized cells for fluorescent microscopy imaging.

  14. Left-right asymmetric cell intercalation drives directional collective cell movement in epithelial morphogenesis

    NASA Astrophysics Data System (ADS)

    Sato, Katsuhiko; Hiraiwa, Tetsuya; Maekawa, Emi; Isomura, Ayako; Shibata, Tatsuo; Kuranaga, Erina

    2015-12-01

    Morphogenetic epithelial movement occurs during embryogenesis and drives complex tissue formation. However, how epithelial cells coordinate their unidirectional movement while maintaining epithelial integrity is unclear. Here we propose a novel mechanism for collective epithelial cell movement based on Drosophila genitalia rotation, in which epithelial tissue rotates clockwise around the genitalia. We found that this cell movement occurs autonomously and requires myosin II. The moving cells exhibit repeated left-right-biased junction remodelling, while maintaining adhesion with their neighbours, in association with a polarized myosin II distribution. Reducing myosinID, known to cause counter-clockwise epithelial-tissue movement, reverses the myosin II distribution. Numerical simulations revealed that a left-right asymmetry in cell intercalation is sufficient to induce unidirectional cellular movement. The cellular movement direction is also associated with planar cell-shape chirality. These findings support a model in which left-right asymmetric cell intercalation within an epithelial sheet drives collective cellular movement in the same direction.

  15. A novel membrane-less direct alcohol fuel cell

    NASA Astrophysics Data System (ADS)

    Yi, Qingfeng; Chen, Qinghua; Yang, Zheng

    2015-12-01

    Membrane-less fuel cell possesses such advantages as simplified design and lower cost. In this paper, a membrane-less direct alcohol fuel cell is constructed by using multi-walled carbon nanotubes (MWCNT) supported Pd and ternary PdSnNi composites as the anode catalysts and Fe/C-PANI composite, produced by direct pyrolysis of Fe-doped polyaniline precursor, as the oxygen reduction reaction (ORR) catalyst. The alcohols investigated in the present study are methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol and sec-butanol. The cathode catalyst Fe/C-PANI is electrochemically inactive to oxidation of the alcohols. The performance of the cell with various alcohols in 1 mol L-1 NaOH solution on either Pd/MWCNT or PdSnNi/MWCNT catalyst has been evaluated. In any case, the performance of the cell using the anode catalyst PdSnNi/MWCNT is considerably better than Pd/MWCNT. For the PdSnNi/MWCNT, the maximum power densities of the cell using methanol (0.5 mol L-1), ethanol (0.5 mol L-1), n-propanol (0.5 mol L-1), iso-propanol (0.5 mol L-1), n-butanol (0.2 mol L-1), iso-butanol (0.2 mol L-1) and sec-butanol (0.2 mol L-1) are 0.34, 1.03, 1.07, 0.44, 0.50, 0.31 and 0.15 mW cm-2, respectively.

  16. Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications

    SciTech Connect

    Carlstrom, Charles, M., Jr.

    2009-07-07

    This report is the final technical report for DOE Program DE-FC36-04GO14301 titled “Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications”. Due to the public nature of this report some of the content reported in confidential reports and meetings to the DOE is not covered in detail in this report and some of the content has been normalized to not show actual values. There is a comparison of the projects accomplishments with the objectives, an overview of some of the key subsystem work, and a review of the three levels of prototypes demonstrated during the program. There is also a description of the eventual commercial product and market this work is leading towards. The work completed under this program has significantly increased the understanding of how Direct Methanol Fuel Cells (DMFC) can be deployed successfully to power consumer electronic devices. The prototype testing has demonstrated the benefits a direct methanol fuel cell system has over batteries typically used for powering consumer electronic devices. Three generations of prototypes have been developed and tested for performance, robustness and life. The technologies researched and utilized in the fuel cell stack and related subsystems for these prototypes are leveraged from advances in other industries such as the hydrogen fueled PEM fuel cell industry. The work under this program advanced the state of the art of direct methanol fuel cells. The system developed by MTI micro fuel cells aided by this program differs significantly from conventional DMFC designs and offers compelling advantages in the areas of performance, life, size, and simplicity. The program has progressed as planned resulting in the completion of the scope of work and available funding in December 2008. All 18 of the final P3 prototypes builds have been tested and the results showed significant improvements over P2 prototypes in build yield, initial performance, and durability. The systems have

  17. Resolving the active versus passive conundrum for head direction cells.

    PubMed

    Shinder, M E; Taube, J S

    2014-06-13

    Head direction (HD) cells have been identified in a number of limbic system structures. These cells encode the animal's perceived directional heading in the horizontal plane and are dependent on an intact vestibular system. Previous studies have reported that the responses of vestibular neurons within the vestibular nuclei are markedly attenuated when an animal makes a volitional head turn compared to passive rotation. This finding presents a conundrum in that if vestibular responses are suppressed during an active head turn how is a vestibular signal propagated forward to drive and update the HD signal? This review identifies and discusses four possible mechanisms that could resolve this problem. These mechanisms are: (1) the ascending vestibular signal is generated by more than just vestibular-only neurons, (2) not all vestibular-only neurons contributing to the HD pathway have firing rates that are attenuated by active head turns, (3) the ascending pathway may be spared from the affects of the attenuation in that the HD system receives information from other vestibular brainstem sites that do not include vestibular-only cells, and (4) the ascending signal is affected by the inhibited vestibular signal during an active head turn, but the HD circuit compensates and uses the altered signal to accurately update the current HD. Future studies will be needed to decipher which of these possibilities is correct.

  18. Directing the assembly of nanostructured films with living cells

    NASA Astrophysics Data System (ADS)

    Brinker, C. Jeffrey

    2007-03-01

    This talk describes our recent discovery of the ability of living cells to organize extended nanostructures and nano-objects in a manner that creates a unique, highly biocompatible nano//bio interface (Science 313, 337-340, 2006). We find that, using short chain phospholipids to direct the formation of thin film silica mesophases during evaporation-induced self-assembly, the introduction of cells (so far yeast and bacteria) alters profoundly the inorganic self-assembly pathway. Cells actively organize around themselves an ordered, multilayered lipid-membrane that interfaces coherently with a lipid-templated silica mesophase. This bio/nano interface is unique in that it withstands drying (even evacuation) without cracking or the development of tensile stresses -- yet it maintains accessibility to molecules, proteins/antibodies, plasmids, etc - introduced into the 3D silica host. Additionally cell viability is preserved for weeks to months in the absence of buffer, making these constructs useful as standalone cell-based sensors. The bio/nano interfaces we describe do not form `passively' -- rather they are a consequence of the cell's ability to sense and actively respond to external stimuli. During EISA, solvent evaporation concentrates the extracellular environment in osmolytes. In response to this hyperosmotic stress, the cells release water, creating a gradient in pH, which is maintained within the adjoining nanostructured host and serves to localize lipids, proteins, plasmids, lipidized nanocrystals, and a variety of other components at the cellular surface. This active organization of the bio/nano interface can be accomplished during ink-jet printing or selective wetting -- processes allowing patterning of cellular arrays - and even spatially-defined genetic modification.

  19. Spatially patterned matrix elasticity directs stem cell fate

    NASA Astrophysics Data System (ADS)

    Yang, Chun; DelRio, Frank W.; Ma, Hao; Killaars, Anouk R.; Basta, Lena P.; Kyburz, Kyle A.; Anseth, Kristi S.

    2016-08-01

    There is a growing appreciation for the functional role of matrix mechanics in regulating stem cell self-renewal and differentiation processes. However, it is largely unknown how subcellular, spatial mechanical variations in the local extracellular environment mediate intracellular signal transduction and direct cell fate. Here, the effect of spatial distribution, magnitude, and organization of subcellular matrix mechanical properties on human mesenchymal stem cell (hMSCs) function was investigated. Exploiting a photodegradation reaction, a hydrogel cell culture substrate was fabricated with regions of spatially varied and distinct mechanical properties, which were subsequently mapped and quantified by atomic force microscopy (AFM). The variations in the underlying matrix mechanics were found to regulate cellular adhesion and transcriptional events. Highly spread, elongated morphologies and higher Yes-associated protein (YAP) activation were observed in hMSCs seeded on hydrogels with higher concentrations of stiff regions in a dose-dependent manner. However, when the spatial organization of the mechanically stiff regions was altered from a regular to randomized pattern, lower levels of YAP activation with smaller and more rounded cell morphologies were induced in hMSCs. We infer from these results that irregular, disorganized variations in matrix mechanics, compared with regular patterns, appear to disrupt actin organization, and lead to different cell fates; this was verified by observations of lower alkaline phosphatase (ALP) activity and higher expression of CD105, a stem cell marker, in hMSCs in random versus regular patterns of mechanical properties. Collectively, this material platform has allowed innovative experiments to elucidate a novel spatial mechanical dosing mechanism that correlates to both the magnitude and organization of spatial stiffness.

  20. Spatially patterned matrix elasticity directs stem cell fate

    PubMed Central

    Yang, Chun; DelRio, Frank W.; Ma, Hao; Killaars, Anouk R.; Basta, Lena P.; Kyburz, Kyle A.; Anseth, Kristi S.

    2016-01-01

    There is a growing appreciation for the functional role of matrix mechanics in regulating stem cell self-renewal and differentiation processes. However, it is largely unknown how subcellular, spatial mechanical variations in the local extracellular environment mediate intracellular signal transduction and direct cell fate. Here, the effect of spatial distribution, magnitude, and organization of subcellular matrix mechanical properties on human mesenchymal stem cell (hMSCs) function was investigated. Exploiting a photodegradation reaction, a hydrogel cell culture substrate was fabricated with regions of spatially varied and distinct mechanical properties, which were subsequently mapped and quantified by atomic force microscopy (AFM). The variations in the underlying matrix mechanics were found to regulate cellular adhesion and transcriptional events. Highly spread, elongated morphologies and higher Yes-associated protein (YAP) activation were observed in hMSCs seeded on hydrogels with higher concentrations of stiff regions in a dose-dependent manner. However, when the spatial organization of the mechanically stiff regions was altered from a regular to randomized pattern, lower levels of YAP activation with smaller and more rounded cell morphologies were induced in hMSCs. We infer from these results that irregular, disorganized variations in matrix mechanics, compared with regular patterns, appear to disrupt actin organization, and lead to different cell fates; this was verified by observations of lower alkaline phosphatase (ALP) activity and higher expression of CD105, a stem cell marker, in hMSCs in random versus regular patterns of mechanical properties. Collectively, this material platform has allowed innovative experiments to elucidate a novel spatial mechanical dosing mechanism that correlates to both the magnitude and organization of spatial stiffness. PMID:27436901

  1. Anode catalysts for direct ethanol fuel cells utilizing directly solar light illumination.

    PubMed

    Chu, Daobao; Wang, Shuxi; Zheng, Peng; Wang, Jian; Zha, Longwu; Hou, Yuanyuan; He, Jianguo; Xiao, Ying; Lin, Huashui; Tian, Zhaowu

    2009-01-01

    Shine a light: A PtNiRu/TiO(2) anode catalyst for direct ethanol fuel cells shows photocatalytic activity. The peak current density for ethanol oxidation under solar light illumination is 2-3 times greater than that in the absence of solar light. Ethanol is oxidized by light-generated holes, and the electrons are collected by the TiO(2) support to generate the oxidation current.Novel PtNiRu/TiO(2) anode catalysts for direct ethanol fuel cells (DEFCs) were prepared from PtNiRu nanoparticles (1:1:1 atomic ratios) and a nanoporous TiO(2) film by a sol-gel and electrodeposition method. The performances of the catalysts for ethanol oxidation were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results indicate a remarkable enhancement of activity for ethanol oxidation under solar light illumination. Under solar light illumination, the generated oxidation peak current density is 24.6 mA cm(-2), which is about 2.5 times higher than that observed without solar light (9.9 mA cm(-2)). The high catalytic activity of the PtNiRu/TiO(2) complex catalyst for the electrooxidation of ethanol may be attributed to the modified metal/nanoporous TiO(2) film, and the enhanced electrooxidation of ethanol under solar light may be due to the photogeneration of holes in the modified nanoporous TiO(2) film.

  2. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns.

    PubMed

    Premnath, Priyatha; Tavangar, Amirhossein; Tan, Bo; Venkatakrishnan, Krishnan

    2015-09-10

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  3. A review of induced pluripotent stem cell, direct conversion by trans-differentiation, direct reprogramming and oligodendrocyte differentiation.

    PubMed

    Prasad, Ankshita; Manivannan, Janani; Loong, Daniel T B; Chua, Soo M; Gharibani, Payam M; All, Angelo H

    2016-03-01

    Rapid progress in the field of stem cell therapy and cellular reprogramming provides convincing evidence of its feasibility in treating a wide range of pathologies through autologous cell replacement therapy. This review article describes in detail on three widely used approaches of somatic cell reprogramming: induced pluripotent stem cells, direct conversion and direct reprogramming, in the context of demyelination in the CNS. The potential limitations of each reprogramming technique are reviewed along with their distinct molecular approach to reprogramming. This is followed by an analysis on the scopes and challenges of its translational applications in deriving oligodendrocyte progenitor cells and oligodendrocytes for cell replacement treatment of demyelinating conditions in the CNS.

  4. Frontline Science: Shh production and Gli signaling is activated in vivo in lung, enhancing the Th2 response during a murine model of allergic asthma.

    PubMed

    Standing, Ariane S I; Yánez, Diana C; Ross, Rosie; Crompton, Tessa; Furmanski, Anna L

    2017-02-24

    The pathophysiology of allergic asthma is driven by Th2 immune responses after aeroallergen inhalation. The mechanisms that initiate, potentiate, and regulate airway allergy are incompletely characterized. We have shown that Hh signaling to T cells, via downstream Gli transcription factors, enhances T cell conversion to a Th2 phenotype. In this study, we showed for the first time, to our knowledge, that Gli-dependent transcription is activated in T cells in vivo during murine AAD, a model for the immunopathology of asthma, and that genetic repression of Gli signaling in T cells decreases the differentiation and recruitment of Th2 cells to the lung. T cells were not the only cells that expressed activated Gli during AAD. A substantial proportion of eosinophils and lung epithelial cells, both central mediators of the immunopathology of asthma, also underwent Hh/Gli signaling. Finally, Shh increased Il-4 expression in eosinophils. We therefore propose that Hh signaling during AAD is complex, involving multiple cell types, signaling in an auto- or paracrine fashion. Improved understanding of the role of this major morphogenetic pathway in asthma may give rise to new drug targets for this chronic condition.

  5. Low level of LAT-PLC-γ1 interaction is associated with Th2 polarized differentiation: a contributing factor to the etiology of asthma.

    PubMed

    Peng, Xiaohua; Cui, Zhilei; Gu, Wen; Xu, Weiguo; Guo, Xuejun

    2014-07-01

    Linker for activation of T cells (LAT) is a key adaptor in the T cell receptor (TCR) signaling pathway. The expression of LAT is lower in asthmatic patients than that in healthy people, but there is little knowledge about the mechanism underlying this phenomenon. This study was aimed to determine whether LAT-PLC-γ1 interaction was involved in the development of asthma. It was shown that the phosphorylation of PLC-γ1 decreased in the asthmatic mouse model and Th2 cell differentiated CD4(+) T cells. In addition, depleted endogenous PLC-γ1 promoted CD4(+) T cells to differentiate into IL-4-Productor. It was therefore concluded that the low level of LAT-PLC-γ1 interaction was associated with Th2 polarized differentiation, and this may contribute to the etiology of asthma.

  6. Novel Materials for High Efficiency Direct Methanol Fuel Cells

    SciTech Connect

    Carson, Stephen; Mountz, David; He, Wensheng; Zhang, Tao

    2013-12-31

    Direct methanol fuel cell membranes were developed using blends of different polyelectrolytes with PVDF. The membranes showed complex relationships between polyelectrolyte chemistry, morphology, and processing. Although the PVDF grade was found to have little effect on the membrane permselectivity, it does impact membrane conductivity and methanol permeation values. Other factors, such as varying the polyelectrolyte polarity, using varying crosslinking agents, and adjusting the equivalent weight of the membranes impacted methanol permeation, permselectivity, and areal resistance. We now understand, within the scope of the project work completed, how these inter-related performance properties can be tailored to achieve a balance of performance.

  7. Starting characteristics of direct current motors powered by solar cells

    NASA Technical Reports Server (NTRS)

    Singer, S.; Appelbaum, J.

    1989-01-01

    Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

  8. Quercetin exhibits adjuvant activity by enhancing Th2 immune response in ovalbumin immunized mice.

    PubMed

    Singh, Divya; Tanwar, Himanshi; Jayashankar, Bindhya; Sharma, Jyoti; Murthy, Swetha; Chanda, Sudipta; Singh, Shashi Bala; Ganju, Lilly

    2017-04-02

    Quercetin, one of the most abundant of plant flavonoids, has been studied with a great deal of attention over the last several decades mainly for its properties in inflammation and allergy. In this study, we are reporting for the first time the in vivo immunostimulatory activity of quercetin in ovalbumin immunized Balb/c mice. Administration of quercetin (50mg/kg body weight) along with ovalbumin antigen showed increased ovalbumin specific serum IgG antibody titres in comparison to the control group (p<0.05). Quercetin administration not only showed predominance of Th2 immune response by increasing the IgG1 antibody titres, but also increased the infiltration of CD11c(+) dendritic cells in the mouse peritoneum and also increased LPS activated IL-1β and nitric oxide (NO) production by peritoneal macrophages. Expression of Tbx21, GATA-3 and Oct-2 proteins also enhanced in splenocytes of quercetin administered mice. Quercetin also did not cause any hemolysis in human RBCs. Overall, our findings strongly demonstrate the novel in vivo immunostimulatory and adjuvant potentials of quercetin.

  9. [The evolution of the Th2 immune responses and its relationships with parasitic diseases and allergy].

    PubMed

    Caraballo, Luis; Zakzuk, Josefina

    2012-01-01

    A variety of links occur between parasites, particularly helminths, and allergic diseases--both common conditions of epidemiological importance in tropical regions. Although speculations are often made about the effects of parasitic diseases on the evolution of the immune system, the selective forces that have shaped the allergic response are unknown and probably include evolutionary mechanisms different to those traditionally reported. Helminths, infectious and antigenic sources that induce allergic-like responses, established themselves as parasites in organisms that already had cell groups related to the type 2 immunity. An essential component in the relationship between helminths and their hosts is that the former induce immunosuppression, creating a kind of balance that allows the survival of both. The development of this equilibrium undoubtedly includes adaptations in both organisms, and the survival of the parasite is the result of (a) acquiring immune suppressor mechanisms and (b) finding hosts with lower intensity of the type 2 response. This in turn suggests that although helminth infections have influenced the formation of type 2 immunity, they have not been an important selective force in the particular case of allergic response. The latter is more related to an exaggerated Th2/IgE response.

  10. Twinned tetragonal structure and equation of state of NaTh 2F 9

    NASA Astrophysics Data System (ADS)

    Grzechnik, Andrzej; Morgenroth, Wolfgang; Friese, Karen

    2008-04-01

    The crystal structure and stability of NaTh 2F 9 have been studied using thermal analysis, powder X-ray diffraction at atmospheric conditions, and single-crystal X-ray diffraction at high pressure. Sodium dithorium fluoride is stable at least up to 5.0 GPa at room temperature and to 954 K at ambient pressure. In contrast to earlier investigations, which have reported the structure to be cubic ( I4¯3m, Z=4), we observe a tetragonal distortion of the lattice. The actual crystal structure ( I4¯2m, Z=4) is twinned and composed of corner-sharing distorted ThF 9 tricapped trigonal prisms and distorted NaF 6 octahedra. The twinning element is a three-fold axis from cubic symmetry. The ThF 9 polyhedra are rigid and it is the volume changes of the octahedra around the Na atoms that have the major contribution to the bulk compressibility. The zero-pressure bulk modulus B0 and the unit-cell volume at ambient pressure V0 are equal to 99(6) GPa and 663.1(1.0) Å 3, respectively, with the fixed first pressure derivative of the bulk modulus B'=4.00. An inspection of the known crystalline phases in the system NaF-ThF 4 reveals that their bulk moduli increase with the increasing ThF 4 content.

  11. Effect of murine exposure to gamma rays on the interplay between Th1 and Th2 lymphocytes.

    PubMed

    Ghazy, Amany A; Abu El-Nazar, Salma Y; Ghoneim, Hossam E; Taha, Abdul-Rahman M; Abouelella, Amira M

    2015-01-01

    Gamma radiation radiotherapy is one of the widely used treatments for cancer. There is an accumulating evidence that adaptive immunity is significantly contributes to the efficacy of radiotherapy. This study is carried out to investigate the effect of gamma rays on the interplay between Th1/Th2 response, splenocyte lymphoproliferative response to polyclonal mitogenic activators and lymphocytic capacity to produce IL-12 and IL-10 in mice. Results showed that exposure of intact spleens to different doses of γ-rays (5, 10, 20 Gy) caused spontaneous and dose-dependent immune stimulation manifested by enhanced cell proliferation and elevated IL-12 production with decreased IL-10 release (i.e., Th1 bias). While exposure of splenocytes suspension to different doses of γ-rays (5, 10, 20 Gy) showed activation in splenocytes stimulated by PWM at 5 Gy then a state of conventional immune suppression that is characterized by being dose-dependent and is manifested by decreased cell proliferation and IL-12 release accompanied by increase in IL-10 production (i.e., Th2 bias). In addition, we investigated the exposure of whole murine bodies to different doses of γ-rays and found that the exposure to low dose γ-rays (0.2 Gy) caused a state of immune stimulation terminated by a remarkable tendency for immune suppression. Exposure to 5 or 10 Gy of γ-rays resulted in a state of immune stimulation (Th1 bias), but exposure to 20 Gy showed a standard state of immune suppression (Th2 bias). The results indicated that apparently we can control the immune response by controlling the dose of γ-rays.

  12. Effect of murine exposure to gamma rays on the interplay between Th1 and Th2 lymphocytes

    PubMed Central

    Ghazy, Amany A.; Abu El-Nazar, Salma Y.; Ghoneim, Hossam E.; Taha, Abdul-Rahman M.; Abouelella, Amira M.

    2015-01-01

    Gamma radiation radiotherapy is one of the widely used treatments for cancer. There is an accumulating evidence that adaptive immunity is significantly contributes to the efficacy of radiotherapy. This study is carried out to investigate the effect of gamma rays on the interplay between Th1/Th2 response, splenocyte lymphoproliferative response to polyclonal mitogenic activators and lymphocytic capacity to produce IL-12 and IL-10 in mice. Results showed that exposure of intact spleens to different doses of γ-rays (5, 10, 20 Gy) caused spontaneous and dose-dependent immune stimulation manifested by enhanced cell proliferation and elevated IL-12 production with decreased IL-10 release (i.e., Th1 bias). While exposure of splenocytes suspension to different doses of γ-rays (5, 10, 20 Gy) showed activation in splenocytes stimulated by PWM at 5 Gy then a state of conventional immune suppression that is characterized by being dose-dependent and is manifested by decreased cell proliferation and IL-12 release accompanied by increase in IL-10 production (i.e., Th2 bias). In addition, we investigated the exposure of whole murine bodies to different doses of γ-rays and found that the exposure to low dose γ-rays (0.2 Gy) caused a state of immune stimulation terminated by a remarkable tendency for immune suppression. Exposure to 5 or 10 Gy of γ-rays resulted in a state of immune stimulation (Th1 bias), but exposure to 20 Gy showed a standard state of immune suppression (Th2 bias). The results indicated that apparently we can control the immune response by controlling the dose of γ-rays. PMID:25914644

  13. The core planar cell polarity gene, Vangl2, directs adult corneal epithelial cell alignment and migration

    PubMed Central

    Findlay, Amy S.; Panzica, D. Alessio; Walczysko, Petr; Holt, Amy B.; Henderson, Deborah J.; West, John D.; Rajnicek, Ann M.

    2016-01-01

    This study shows that the core planar cell polarity (PCP) genes direct the aligned cell migration in the adult corneal epithelium, a stratified squamous epithelium on the outer surface of the vertebrate eye. Expression of multiple core PCP genes was demonstrated in the adult corneal epithelium. PCP components were manipulated genetically and pharmacologically in human and mouse corneal epithelial cells in vivo and in vitro. Knockdown of VANGL2 reduced the directional component of migration of human corneal epithelial (HCE) cells without affecting speed. It was shown that signalling through PCP mediators, dishevelled, dishevelled-associated activator of morphogenesis and Rho-associated protein kinase directs the alignment of HCE cells by affecting cytoskeletal reorganization. Cells in which VANGL2 was disrupted tended to misalign on grooved surfaces and migrate across, rather than parallel to the grooves. Adult corneal epithelial cells in which Vangl2 had been conditionally deleted showed a reduced rate of wound-healing migration. Conditional deletion of Vangl2 in the mouse corneal epithelium ablated the normal highly stereotyped patterns of centripetal cell migration in vivo from the periphery (limbus) to the centre of the cornea. Corneal opacity owing to chronic wounding is a major cause of degenerative blindness across the world, and this study shows that Vangl2 activity is required for directional corneal epithelial migration. PMID:27853583

  14. Direct determination of phosphatase activity from physiological substrates in cells.

    PubMed

    Ren, Zhongyuan; Do, Le Duy; Bechkoff, Géraldine; Mebarek, Saida; Keloglu, Nermin; Ahamada, Saandia; Meena, Saurabh; Magne, David; Pikula, Slawomir; Wu, Yuqing; Buchet, René

    2015-01-01

    A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP) performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1) mg(-1) for PPi, to 56 ± 11 nmol min(-1) mg(-1) for AMP, to 79 ± 23 nmol min(-1) mg(-1) for beta-glycerophosphate and to 73 ± 15 nmol min(-1) mg(-1) for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

  15. Direct fuel cells: Putting power where you need it!

    SciTech Connect

    Glenn, D.R.

    1996-12-31

    The world`s largest capacity carbonate fuel cell power plant is expected to commence operation at a substation located in California on the City of Santa Clara`s electric system in the first half of 1996. With a nominal capacity of two megawatts (1.8-MW delivered), the plant is a first-of-a-kind demonstration of a power system based on an internally-reforming fuel cell technology called the Direct Fuel Cell (DFC), developed by the Energy Research Corporation (ERC). As important as the introduction of the technology itself, is its use in a distributed generation strategy. The power plant being demonstrated at Santa Clara is an enabling technology to advance the applicability of locally-sited generation usually at smaller scales, say 1-6 megawatts, near served loads. This is not a new idea as it relates to previous incarnations as total energy systems or cogenerators, where the by-product heat from the usually inefficient combustion-driven generator is recovered and applied for spaceheating, raising steam, etc. What makes the fuel cell-based system special is that it operates quietly, emits virtually no pollution, and converts the energy value of the inlet gaseous fuel(s) to electricity electrochemically (non-Carnot cycle limited). For the ERC technology, this translates to attainable electric efficiencies of over 50%, or heat rates of less than 6800 BTU/kWh, even in smaller size equipment.

  16. Performance of direct methanol polymer electrolyte fuel cell

    SciTech Connect

    Shin, Dong Ryul; Jung, Doo Hwan; Lee, Chang Hyeong; Chun, Young Gab

    1996-12-31

    Direct methanol fuel cells (DMFC) using polymer electrolyte membrane are promising candidate for application of portable power sources and transportation applications because they do not require any fuel processing equipment and can be operated at low temperature of 60{degrees}C - 130{degrees}C. Elimination of the fuel processor results in simpler design, higher operation reliability, lower weight volume, and lower capital and operating cost. However, methanol as a fuel is relatively electrochemical inert, so that kinetics of the methanol oxidation is too slow. Platinum and Pt-based binary alloy electrodes have been extensively studied for methanol electro-oxidation in acid electrolyte at ambient and elevated temperatures. Particularly, unsupported carbon Pt-Ru catalyst was found to be superior to the anode of DMFC using a proton exchange membrane electrolyte (Nafion). The objective of this study is to develop the high performance DNTC. This paper summarizes the results from half cell and single cell tests, which focus on the electrode manufacturing process, catalyst selection, and operating conditions of single cell such as methanol concentration, temperature and pressure.

  17. Anionic-cationic bi-cell design for direct methanol fuel cell stack

    NASA Astrophysics Data System (ADS)

    Kim, Hyea; Ünlü, Murat; Zhou, Junfeng; Anestis-Richard, Irene; Kohl, Paul A.

    A new fuel cell stack design is described using an anion exchange membrane (AEM) fuel cell and a proton exchange membrane (PEM) fuel cell in series with a single fuel tank servicing both anodes in a passive direct methanol fuel cell configuration. The anionic-cationic bi-cell stack has alkaline and acid fuel cells in series (twice the voltage), one fuel tank, and simplified water management. The series connection between the two cells involves shorting the cathode of the anionic cell to the anode of the acidic cell. It is shown that these two electrodes are at essentially the same potential which avoids an undesired potential difference and resulting loss in current between the two electrodes. Further, the complimentary direction of water transport in the two kinds of fuel cells simplifies water management at both the anodes and cathodes. The effect of ionomer content on the AEM electrode potential and the activity of methanol oxidation were investigated. The individual performance of AEM and PEM fuel cells were evaluated. The effect of ion-exchange capacity in the alkaline electrodes was studied. A fuel wicking material in the methanol fuel tank was used to provide orientation-independent operation. The open circuit potential of the bi-cell was 1.36 V with 2.0 M methanol fuel and air at room temperature.

  18. Nanotopography guides and directs cell migration in amoeboid and epithelial cells

    NASA Astrophysics Data System (ADS)

    Lee, Rachel; Das, Satarupa; Hourwitz, Matthew; Sun, Xiaoyu; Parent, Carole; Fourkas, John; Losert, Wolfgang

    Cell migration plays a critical role in development, angiogenesis, immune response, wound healing, and cancer metastasis. In many cases, cells also move in the context of a matrix of collagen fibers, and the alignment of these fibers can both affect the migration phenotype and guide cells. Here we show that both fast and slow migrating cells - amoeboid HL-60 and epithelial MCF10A - are affected in similar ways by micro/nanostructures with dimensions similar to those of collagen fibers. Cell alignment enhances the efficiency of migration by increasing directional persistence.

  19. Direct reprogramming of somatic cells into neural stem cells or neurons for neurological disorders

    PubMed Central

    Hou, Shaoping; Lu, Paul

    2016-01-01

    Direct reprogramming of somatic cells into neurons or neural stem cells is one of the most important frontier fields in current neuroscience research. Without undergoing the pluripotency stage, induced neurons or induced neural stem cells are a safer and timelier manner resource in comparison to those derived from induced pluripotent stem cells. In this prospective, we review the recent advances in generation of induced neurons and induced neural stem cells in vitro and in vivo and their potential treatments of neurological disorders. PMID:26981072

  20. Mutual enhancement of differentiation of osteoblasts and osteocytes occurs through direct cell-cell contact.

    PubMed

    Fujita, Koji; Xing, Qian; Khosla, Sundeep; Monroe, David G

    2014-11-01

    There is increasing evidence that osteocytes regulate multiple aspects of bone remodeling through bi-directional communication with osteoblasts. This is potentially mediated through cell-cell contact via osteocytic dendritic processes, through the activity of secreted factors, or both. To test whether cell-cell contact affects gene expression patterns in osteoblasts and osteocytes, we used a co-culture system where calvarial osteoblasts and IDG-SW3 osteocytes were allowed to touch through a porous membrane, while still being physically separated to allow for phenotypic characterization. Osteoblast/osteocyte cell-contact resulted in up-regulation of osteoblast differentiation genes in the osteoblasts, when compared to wells where no cell contact was allowed. Examination of osteocyte gene expression when in direct contact with osteoblasts also revealed increased expression of osteocyte-specific genes. These data suggest that physical contact mutually enhances both the osteoblastic and osteocytic character of each respective cell type. Interestingly, Gja1 (a gap junction protein) was increased in the osteoblasts only when in direct contact with the osteocytes, suggesting that Gja1 may mediate some of the effects of direct cell contact. To test this hypothesis, we treated the direct contact system with the gap junction inhibitor 18-alpha-glycyrrhetinic acid and found that Bglap expression was significantly inhibited. This suggests that osteocytes may regulate late osteoblast differentiation at least in part through Gja1. Identification of the specific factors involved in the enhancement of differentiation of both osteoblasts and osteocytes when in direct contact will uncover new biology concerning how these bone cells communicate.

  1. Elevation of serum IgE level and peripheral eosinophil count during T lymphocyte-directed gene therapy for ADA deficiency: implication of Tc2-like cells after gene transduction procedure.

    PubMed

    Kawamura, N; Ariga, T; Ohtsu, M; Yamada, M; Tame, A; Furuta, H; Kobayashi, I; Okano, M; Yanagihara, Y; Sakiyama, Y

    1998-11-01

    We have successfully carried out T-cell-directed gene therapy for a boy with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA SCID) and unexpectedly found an elevation of serum IgE level and peripheral eosinophil count during the course. More than 90% of transduced cells cultured for 7-11 days before infusion into the patient were positive for CD8 and expressed Th2-type cytokine genes such as IL-4, IL-5 and IL-13. Furthermore, CD4(+) T-depleted PBMC (peripheral blood mononuclear cells) from the patient synthesized IgE in vitro by stimulation with IL-4. Collectively, these results suggested that Tc2-like cells in the transduced cells have distinct immunological functions to help IgE synthesis and activate eosinophils.

  2. Human induced pluripotent stem cell differentiation and direct transdifferentiation into corneal epithelial-like cells

    PubMed Central

    Cieślar-Pobuda, Artur; Rafat, Mehrdad; Knoflach, Viktoria; Skonieczna, Magdalena; Hudecki, Andrzej; Małecki, Andrzej; Urasińska, Elżbieta; Ghavami, Seaid; Łos, Marek J.

    2016-01-01

    The corneal epithelium is maintained by a small pool of tissue stem cells located at the limbus. Through certain injuries or diseases this pool of stem cells may get depleted. This leads to visual impairment. Standard treatment options include autologous or allogeneic limbal stem cell (LSC) transplantation, however graft rejection and chronic inflammation lowers the success rate over long time. Induced pluripotent stem (iPS) cells have opened new possibilities for treating various diseases with patient specific cells, eliminating the risk of immune rejection. In recent years, several protocols have been developed, aimed at the differentiation of iPS cells into the corneal epithelial lineage by mimicking the environmental niche of limbal stem cells. However, the risk of teratoma formation associated with the use of iPS cells hinders most applications from lab into clinics. Here we show that the differentiation of iPS cells into corneal epithelial cells results in the expression of corneal epithelial markers showing a successful differentiation, but the process is long and the level of gene expression for the pluripotency markers does not vanish completely. Therefore we set out to determine a direct transdifferentiation approach to circumvent the intermediate state of pluripotency (iPS-stage). The resulting cells, obtained by direct transdifferentiation of fibroblasts into limbal cells, exhibited corneal epithelial cell morphology and expressed corneal epithelial markers. Hence we shows for the first time a direct transdifferentiation of human dermal fibroblasts into the corneal epithelial lineage that may serve as source for corneal epithelial cells for transplantation approaches. PMID:27275539

  3. Improved Anode for a Direct Methanol Fuel Cell

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas; Narayanan, Sekharipuram

    2005-01-01

    A modified chemical composition has been devised to improve the performance of the anode of a direct methanol fuel cell. The main feature of the modified composition is the incorporation of hydrous ruthenium oxide into the anode structure. This modification can reduce the internal electrical resistance of the cell and increase the degree of utilization of the anode catalyst. As a result, a higher anode current density can be sustained with a smaller amount of anode catalyst. These improvements can translate into a smaller fuel-cell system and higher efficiency of conversion. Some background information is helpful for understanding the benefit afforded by the addition of hydrous ruthenium oxide. The anode of a direct methanol fuel cell sustains the electro-oxidation of methanol to carbon dioxide in the reaction CH3OH + H2O--->CO2 + 6H(+) + 6e(-). An electrocatalyst is needed to enable this reaction to occur. The catalyst that offers the highest activity is an alloy of approximately equal numbers of atoms of the noble metals platinum and ruthenium. The anode is made of a composite material that includes high-surface-area Pt/Ru alloy particles and a proton-conducting ionomeric material. This composite is usually deposited onto a polymer-electrolyte (proton-conducting) membrane and onto an anode gas-diffusion/current-collector sheet that is subsequently bonded to the proton-conducting membrane by hot pressing. Heretofore, the areal density of noble-metal catalyst typically needed for high performance has been about 8 mg/cm2. However, not all of the catalyst has been utilized in the catalyzed electro-oxidation reaction. Increasing the degree of utilization of the catalyst would make it possible to improve the performance of the cell for a given catalyst loading and/or reduce the catalyst loading (thereby reducing the cost of the cell). The use of carbon and possibly other electronic conductors in the catalyst layer has been proposed for increasing the utilization of the

  4. Tuning cell adhesion by direct nanostructuring silicon into cell repulsive/adhesive patterns

    SciTech Connect

    Premnath, Priyatha; Venkatakrishnan, Krishnan

    2015-09-10

    Developing platforms that allow tuning cell functionality through incorporating physical, chemical, or mechanical cues onto the material surfaces is one of the key challenges in research in the field of biomaterials. In this respect, various approaches have been proposed and numerous structures have been developed on a variety of materials. Most of these approaches, however, demand a multistep process or post-chemical treatment. Therefore, a simple approach would be desirable to develop bio-functionalized platforms for effectively modulating cell adhesion and consequently programming cell functionality without requiring any chemical or biological surface treatment. This study introduces a versatile yet simple laser approach to structure silicon (Si) chips into cytophobic/cytophilic patterns in order to modulate cell adhesion and proliferation. These patterns are fabricated on platforms through direct laser processing of Si substrates, which renders a desired computer-generated configuration into patterns. We investigate the morphology, chemistry, and wettability of the platform surfaces. Subsequently, we study the functionality of the fabricated platforms on modulating cervical cancer cells (HeLa) behaviour. The results from in vitro studies suggest that the nanostructures efficiently repel HeLa cells and drive them to migrate onto untreated sites. The study of the morphology of the cells reveals that cells evade the cytophobic area by bending and changing direction. Additionally, cell patterning, cell directionality, cell channelling, and cell trapping are achieved by developing different platforms with specific patterns. The flexibility and controllability of this approach to effectively structure Si substrates to cell-repulsive and cell-adhesive patterns offer perceptible outlook for developing bio-functionalized platforms for a variety of biomedical devices. Moreover, this approach could pave the way for developing anti-cancer platforms that selectively repel

  5. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    SciTech Connect

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  6. Early Exposure of Infants to GI Nematodes Induces Th2 Dominant Immune Responses Which Are Unaffected by Periodic Anthelminthic Treatment

    PubMed Central

    Wright, Victoria J.; Ame, Shaali Makame; Haji, Haji Said; Weir, Rosemary E.; Goodman, David; Pritchard, David I.; Ramsan Mohamed, Mahdi; Haji, Hamad Juma; Tielsch, James M.; Stoltzfus, Rebecca J.; Bickle, Quentin D.

    2009-01-01

    We have previously shown a reduction in anaemia and wasting malnutrition in infants <3 years old in Pemba Island, Zanzibar, following repeated anthelminthic treatment for the endemic gastrointestinal (GI) nematodes Ascaris lumbricoides, hookworm and Trichuris trichiura. In view of the low intensity of worm infections in this age group, this was unexpected, and it was proposed that immune responses to the worms rather than their direct effects may play a significant role in morbidity in infants and that anthelminthic treatment may alleviate such effects. Therefore, the primary aims of this study were to characterise the immune response to initial/early GI nematode infections in infants and the effects of anthelminthic treatment on such immune responses. The frequency and levels of Th1/Th2 cytokines (IL-5, IL-13, IFN-γ and IL-10) induced by the worms were evaluated in 666 infants aged 6–24 months using the Whole Blood Assay. Ascaris and hookworm antigens induced predominantly Th2 cytokine responses, and levels of IL-5 and IL-13 were significantly correlated. The frequencies and levels of responses were higher for both Ascaris positive and hookworm positive infants compared with worm negative individuals, but very few infants made Trichuris-specific cytokine responses. Infants treated every 3 months with mebendazole showed a significantly lower prevalence of infection compared with placebo-treated controls at one year following baseline. At follow-up, cytokine responses to Ascaris and hookworm antigens, which remained Th2 biased, were increased compared with baseline but were not significantly affected by treatment. However, blood eosinophil levels, which were elevated in worm-infected children, were significantly lower in treated children. Thus the effect of deworming in this age group on anaemia and wasting malnutrition, which were replicated in this study, could not be explained by modification of cytokine responses but may be related to eosinophil function

  7. Memory and flexibility of cytokine gene expression as separable properties of human T(H)1 and T(H)2 lymphocytes.

    PubMed

    Messi, Mara; Giacchetto, Isabella; Nagata, Kinya; Lanzavecchia, Antonio; Natoli, Gioacchino; Sallusto, Federica

    2003-01-01

    CD4+ T cell priming under T helper type I (T(H)1) or T(H)2 conditions gives rise to polarized cytokine gene expression. We found that in these conditions human naive T cells acquired stable histone hyperacetylation at either the Ifng or Il4 promoter. Effector memory T cells showed polarized cytokine gene acetylation patterns in vivo, whereas central memory T cells had hypoacetylated cytokine genes but acquired polarized acetylation and expression after appropriate stimulation. However, hypoacetylation of the nonexpressed cytokine gene did not lead to irreversible silencing because most T(H)1 and T(H)2 cells acetylated and expressed the alternative gene when stimulated under opposite T(H) conditions. Such cytokine flexibility was absent in a subset of T(H)2 cells that failed to up-regulate T-bet and to express interferon-gamma when stimulated under T(H)1 conditions. Thus, most human CD4+ T cells retain both memory and flexibility of cytokine gene expression.

  8. Directionally Solidified Biopolymer Scaffolds: Mechanical Properties and Endothelial Cell Responses

    PubMed Central

    Meghri, Nichols W.; Donius, Amalie E.; Riblett, Benjamin W.; Martin, Elizabeth J.; Clyne, Alisa Morss; Wegst, Ulrike G.K.

    2011-01-01

    Vascularization is a primary challenge in tissue engineering. To achieve it in a tissue scaffold, an environment with the appropriate structural, mechanical, and biochemical cues must be provided enabling endothelial cells to direct blood vessel growth. While biochemical stimuli such as growth factors can be added through the scaffold material, the culture medium, or both, a well-designed tissue engineering scaffold is required to provide the necessary local structural and mechanical cues. As chitosan is a well-known carrier for biochemical stimuli, the focus of this study was on structure-property correlations, to evaluate the effects of composition and processing conditions on the three-dimensional architecture and properties of freeze-cast scaffolds; to establish whether freeze-cast scaffolds are promising candidates as constructs promoting vascularization; and to conduct initial tissue culture studies with endothelial cells on flat substrates of identical compositions as those of the scaffolds to test whether these are biocompatible and promote cell attachment and proliferation. PMID:21544225

  9. Directionally solidified biopolymer scaffolds: Mechanical properties and endothelial cell responses

    NASA Astrophysics Data System (ADS)

    Meghri, Nicholas W.; Donius, Amalie E.; Riblett, Benjamin W.; Martin, Elizabeth J.; Clyne, Alisa Morss; Wegst, Ulrike G. K.

    2010-07-01

    Vascularization is a primary challenge in tissue engineering. To achieve it in a tissue scaffold, an environment with the appropriate structural, mechanical, and biochemical cues must be provided enabling endothelial cells to direct blood vessel growth. While biochemical stimuli such as growth factors can be added through the scaffold material, the culture medium, or both, a well-designed tissue engineering scaffold is required to provide the necessary local structural and mechanical cues. As chitosan is a well-known carrier for biochemical stimuli, the focus of this study was on structure-property correlations, to evaluate the effects of composition and processing conditions on the three-dimensional architecture and properties of freeze-cast scaffolds; to establish whether freeze-east scaffolds are promising candidates as constructs promoting vascularization; and to conduct initial tissue culture studies with endothelial cells on flat substrates of identical compositions as those of the scaffolds to test whether these are biocompatible and promote cell attachment and proliferation.

  10. Directionally Solidified Biopolymer Scaffolds: Mechanical Properties and Endothelial Cell Responses.

    PubMed

    Meghri, Nichols W; Donius, Amalie E; Riblett, Benjamin W; Martin, Elizabeth J; Clyne, Alisa Morss; Wegst, Ulrike G K

    2010-07-01

    Vascularization is a primary challenge in tissue engineering. To achieve it in a tissue scaffold, an environment with the appropriate structural, mechanical, and biochemical cues must be provided enabling endothelial cells to direct blood vessel growth. While biochemical stimuli such as growth factors can be added through the scaffold material, the culture medium, or both, a well-designed tissue engineering scaffold is required to provide the necessary local structural and mechanical cues. As chitosan is a well-known carrier for biochemical stimuli, the focus of this study was on structure-property correlations, to evaluate the effects of composition and processing conditions on the three-dimensional architecture and properties of freeze-cast scaffolds; to establish whether freeze-cast scaffolds are promising candidates as constructs promoting vascularization; and to conduct initial tissue culture studies with endothelial cells on flat substrates of identical compositions as those of the scaffolds to test whether these are biocompatible and promote cell attachment and proliferation.

  11. A microfluidic direct formate fuel cell on paper.

    PubMed

    Copenhaver, Thomas S; Purohit, Krutarth H; Domalaon, Kryls; Pham, Linda; Burgess, Brianna J; Manorothkul, Natalie; Galvan, Vicente; Sotez, Samantha; Gomez, Frank A; Haan, John L

    2015-08-01

    We describe the first direct formate fuel cell on a paper microfluidic platform. In traditional membrane-less microfluidic fuel cells (MFCs), external pumping consumes power produced by the fuel cell in order to maintain co-laminar flow of the anode stream and oxidant stream to prevent mixing. However, in paper microfluidics, capillary action drives flow while minimizing stream mixing. In this work, we demonstrate a paper MFC that uses formate and hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using these materials we achieve a maximum power density of nearly 2.5 mW/mg Pd. In a series configuration, our MFC achieves an open circuit voltage just over 1 V, and in a parallel configuration, short circuit of 20 mA absolute current. We also demonstrate that the MFC does not require continuous flow of fuel and oxidant to produce power. We found that we can pre-saturate the materials on the paper, stop the electrolyte flow, and still produce approximately 0.5 V for 15 min. This type of paper MFC has potential applications in point-of-care diagnostic devices and other electrochemical sensors.

  12. Studies on an ultrasonic atomization feed direct methanol fuel cell.

    PubMed

    Wu, Chaoqun; Liu, Linghao; Tang, Kai; Chen, Tao

    2017-01-01

    Direct methanol fuel cell (DMFC) is promising as an energy conversion device for the replacement of conventional chemical cell in future, owing to its convenient fuel storage, high energy density and low working temperature. The development of DMFC technology is currently limited by catalyst poison and methanol crossover. To alleviate the methanol crossover, a novel fuel supply system based on ultrasonic atomization is proposed. Experimental investigations on this fuel supply system to evaluate methanol permeation rates, open circuit voltages (OCVs) and polarization curves under a series of conditions have been carried out and reported in this paper. In comparison with the traditional liquid feed DMFC system, it can be found that the methanol crossover under the ultrasonic atomization feed system was significantly reduced because the DMFC reaches a large stable OCV value. Moreover, the polarization performance does not vary significantly with the liquid feed style. Therefore, the cell fed by ultrasonic atomization can be operated with a high concentration methanol to improve the energy density of DMFC. Under the supply condition of relatively high concentration methanol such as 4M and 8M, the maximum power density fed by ultrasonic atomization is higher than liquid by 6.05% and 12.94% respectively.

  13. SHAPE SELECTIVE NANOCATALYSTS FOR DIRECT METHANOL FUEL CELL APPLICATIONS

    SciTech Connect

    Murph, S.

    2012-09-12

    While gold and platinum have long been recognized for their beauty and value, researchers at the Savannah River National Laboratory (SRNL) are working on the nano-level to use these elements for creative solutions to our nation's energy and security needs. Multiinterdisciplinary teams consisting of chemists, materials scientists, physicists, computational scientists, and engineers are exploring unchartered territories with shape-selective nanocatalysts for the development of novel, cost effective and environmentally friendly energy solutions to meet global energy needs. This nanotechnology is vital, particularly as it relates to fuel cells.SRNL researchers have taken process, chemical, and materials discoveries and translated them for technological solution and deployment. The group has developed state-of-the art shape-selective core-shell-alloy-type gold-platinum nanostructures with outstanding catalytic capabilities that address many of the shortcomings of the Direct Methanol Fuel Cell (DMFC). The newly developed nanostructures not only busted the performance of the platinum catalyst, but also reduced the material cost and overall weight of the fuel cell.

  14. Glutathione Depletion Is Linked with Th2 Polarization in Mice with a Retrovirus-Induced Immunodeficiency Syndrome, Murine AIDS: Role of Proglutathione Molecules as Immunotherapeutics

    PubMed Central

    Brundu, Serena; Palma, Linda; Picceri, Giusi Giada; Ligi, Daniela; Orlandi, Chiara; Galluzzi, Luca; Chiarantini, Laura; Casabianca, Anna; Schiavano, Giuditta Fiorella; Santi, Martina; Mannello, Ferdinando; Smietana, Michaël; Magnani, Mauro

    2016-01-01

    ABSTRACT Injection of the LP-BM5 murine leukemia virus into mice causes murine AIDS, a disease characterized by many dysfunctions of immunocompetent cells. To establish whether the disease is characterized by glutathione imbalance, reduced glutathione (GSH) and cysteine were quantified in different organs. A marked redox imbalance, consisting of GSH and/or cysteine depletion, was found in the lymphoid organs, such as the spleen and lymph nodes. Moreover, a significant decrease in cysteine and GSH levels in the pancreas and brain, respectively, was measured at 5 weeks postinfection. The Th2 immune response was predominant at all times investigated, as revealed by the expression of Th1/Th2 cytokines. Furthermore, investigation of the activation status of peritoneal macrophages showed that the expression of genetic markers of alternative activation, namely, Fizz1, Ym1, and Arginase1, was induced. Conversely, expression of inducible nitric oxide synthase, a marker of classical activation of macrophages, was detected only when Th1 cytokines were expressed at high levels. In vitro studies revealed that during the very early phases of infection, GSH depletion and the downregulation of interleukin-12 (IL-12) p40 mRNA were correlated with the dose of LP-BM5 used to infect the macrophages. Treatment of LP-BM5-infected mice with N-(N-acetyl-l-cysteinyl)-S-acetylcysteamine (I-152), an N-acetyl-cysteine supplier, restored GSH/cysteine levels in the organs, reduced the expression of alternatively activated macrophage markers, and increased the level of gamma interferon production, while it decreased the levels of Th2 cytokines, such as IL-4 and IL-5. Our findings thus establish a link between GSH deficiency and Th1/Th2 disequilibrium in LP-BM5 infection and indicate that I-152 can be used to restore the GSH level and a balanced Th1/Th2 response in infected mice. IMPORTANCE The first report of an association between Th2 polarization and alteration of the redox state in LP-BM5

  15. Amelioration of adjuvant-induced arthritis by ursolic acid through altered Th1/Th2 cytokine production.

    PubMed

    Ahmad, Sheikh Fayaz; Khan, Beenish; Bani, Sarang; Suri, K A; Satti, N K; Qazi, G N

    2006-03-01

    The objective of the study was to investigate the activity of ursolic acid (UA) on proinflammatory (Th1) and anti-inflammatory (Th2) cytokines in the peripheral blood of arthritic balb/c mice. Ursolic acid is ubiquitous in the plant kingdom and is a constituent of numerous plants which are having diversified phylogenetic origin and taxonomic position. We applied Cytometric bead array (CBA) technology for simultaneously measurement of these cytokines in adjuvant inflammatory arthritis induced mice treated with ursolic acid in graded oral doses. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate five cytokines in a 50 microl sample volume. The T-helper (Th1) deviated cells produce detectable level of tumor necrosis factor (TNF-alpha), interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), while the Th2 deviated cells produce significant amount of interleukin-4 (IL-4) and interleukin-5 (IL-5). Oral administration of UA at doses of 10, 20, 40, 80 and 160 mg kg(-1) per oral dose inhibited the presence of IL-2, IFN-gamma and TNF-alpha in the peripheral blood.

  16. Biodegradation of benzidine based azodyes Direct red and Direct blue by the immobilized cells of Pseudomonas fluorescens D41.

    PubMed

    Puvaneswari, N; Muthukrishnan, J; Gunasekaran, P

    2002-10-01

    Benzidine based azodyes are proven carcinogens, mutagens and have been linked to bladder cancer of human beings and laboratory animals. The textile and dyestuff manufacturing industry are the two major sources that released azodyes in their effluents. The dye, Direct blue contains two carcinogenic compounds namely benzidine (BZ), 4-amino biphenyl (4-ABP), while the dye Direct red has benzidine (BZ). Among 40 isolates of Pseudomonas fluorescens screened, one isolate designated as D41 was found to be capable of extensively degrading the dyes Direct blue and Direct red. Immobilized cells of P. fluorescens D41 efficiently degraded Direct red (82%) and Direct blue (71%) in the presence of glucose.

  17. Direct Differentiation of Human Pluripotent Stem Cells into Haploid Spermatogenic Cells

    PubMed Central

    Easley, Charles A.; Phillips, Bart T.; McGuire, Megan M.; Barringer, Jennifer M.; Valli, Hanna; Hermann, Brian P.; Simerly, Calvin R.; Rajkovic, Aleksander; Miki, Toshio; Orwig, Kyle E.; Schatten, Gerald P.

    2013-01-01

    Summary Human embryonic (hESCs) and induced pluripotent stem cells (hiPSCs) have been shown to differentiate into primordial germ cells (PGCs) but not into spermatogonia nor haploid spermatocytes or spermatids. Here we show that hESCs and hiPSCs differentiate directly into advanced male germ cell lineages including post-meiotic, spermatid-like cells in vitro without genetic manipulation. Furthermore, our procedure mirrors spermatogenesis in vivo by differentiating pluripotent stem cells into UTF1, PLZF and CDH1-positive spermatogonia-like cells, HIWI and HILI-positive spermatocyte-like cells, and haploid cells expressing acrosin, transition protein 1 and protamine 1, proteins found uniquely in either spermatids and/or sperm. These spermatids show uniparental genomic imprints similar to human sperm on two loci: H19 and IGF2. These results demonstrate that male pluripotent stem cells have the capability to directly differentiate into advanced germ cell lineages and may represent a novel strategy for studying spermatogenesis in vitro. PMID:22921399

  18. Engineering the human pluripotent stem cell microenvironment to direct cell fate.

    PubMed

    Hazeltine, Laurie B; Selekman, Joshua A; Palecek, Sean P

    2013-11-15

    Human pluripotent stem cells (hPSCs), including both embryonic stem cells and induced pluripotent stem cells, offer a potential cell source for research, drug screening, and regenerative medicine applications due to their unique ability to self-renew or differentiate to any somatic cell type. Before the full potential of hPSCs can be realized, robust protocols must be developed to direct their fate. Cell fate decisions are based on components of the surrounding microenvironment, including soluble factors, substrate or extracellular matrix, cell-cell interactions, mechanical forces, and 2D or 3D architecture. Depending on their spatio-temporal context, these components can signal hPSCs to either self-renew or differentiate to cell types of the ectoderm, mesoderm, or endoderm. Researchers working at the interface of engineering and biology have identified various factors which can affect hPSC fate, often based on lessons from embryonic development, and they have utilized this information to design in vitro niches which can reproducibly direct hPSC fate. This review highlights culture systems that have been engineered to promote self-renewal or differentiation of hPSCs, with a focus on studies that have elucidated the contributions of specific microenvironmental cues in the context of those culture systems. We propose the use of microsystem technologies for high-throughput screening of spatial-temporal presentation of cues, as this has been demonstrated to be a powerful approach for differentiating hPSCs to desired cell types.

  19. Human metapneumovirus Induces Reorganization of the Actin Cytoskeleton for Direct Cell-to-Cell Spread

    PubMed Central

    El Najjar, Farah; Cifuentes-Muñoz, Nicolás; Zhu, Haining; Buchholz, Ursula J.; Moncman, Carole L.; Dutch, Rebecca Ellis

    2016-01-01

    Paramyxovirus spread generally involves assembly of individual viral particles which then infect target cells. We show that infection of human bronchial airway cells with human metapneumovirus (HMPV), a recently identified paramyxovirus which causes significant respiratory disease, results in formation of intercellular extensions and extensive networks of branched cell-associated filaments. Formation of these structures is dependent on actin, but not microtubule, polymerization. Interestingly, using a co-culture assay we show that conditions which block regular infection by HMPV particles, including addition of neutralizing antibodies or removal of cell surface heparan sulfate, did not prevent viral spread from infected to new target cells. In contrast, inhibition of actin polymerization or alterations to Rho GTPase signaling pathways significantly decreased cell-to-cell spread. Furthermore, viral proteins and viral RNA were detected in intercellular extensions, suggesting direct transfer of viral genetic material to new target cells. While roles for paramyxovirus matrix and fusion proteins in membrane deformation have been previously demonstrated, we show that the HMPV phosphoprotein extensively co-localized with actin and induced formation of cellular extensions when transiently expressed, supporting a new model in which a paramyxovirus phosphoprotein is a key player in assembly and spread. Our results reveal a novel mechanism for HMPV direct cell-to-cell spread and provide insights into dissemination of respiratory viruses. PMID:27683250

  20. Valsartan Attenuates Atherosclerosis via Upregulating the Th2 Immune Response in Prolonged Angiotensin II-Treated ApoE(-/-) Mice.

    PubMed

    Meng, Kai; Zeng, Qiutang; Lu, Qinghua; Lin, Yingzhong; Wu, Bangwei; Yu, Kunwu; Dong, Zhaoqiang; Zhang, Jianwei; Chai, Meng; Liu, Yuyang; Ji, Qingwei; Zhou, Yujie

    2015-02-09

    Valsartan has a protective effect against hypertension and atherosclerosis in humans and experimental animal models. This study aimed to determine the effect of prolonged treatment with angiotensin II (Ang II) on atherosclerosis and the effect of valsartan on the activity of CD4(+) T lymphocyte subsets. The results showed that prolonged treatment (8 wks) with exogenous Ang II resulted in an increased atherosclerotic plaque size and a switch of stable-to-unstable plaque via modulating on CD4(+) T lymphocyte activity, including an increase in the T helper cell type 1 (Th1) and Th17 cells and a decrease in Th2 and regulatory T (Treg) cells. In contrast, valsartan treatment efficiently reversed the imbalance in CD4(+) T lymphocyte activity, ameliorated atherosclerosis and elicited a stable plaque phenotype in addition to controlling blood pressure. In addition, treatment with anti-interleukin (IL)-5 monoclonal antibodies weakened the antiatherosclerotic effects of valsartan without affecting blood pressure.

  1. Chronic hypersensitivity pneumonitis caused by Saccharopolyspora rectivirgula is not associated with a switch to a Th2 response

    PubMed Central

    Andrews, Kelly; Ghosh, Manik C.; Schwingshackl, Andreas; Rapalo, Gabriel; Luellen, Charlean; Waters, Christopher M.

    2015-01-01

    Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease that develops following repeated exposure to inhaled environmental antigens. The disease results in alveolitis and granuloma formation and may progress to a chronic form associated with fibrosis; a greater understanding of the immunopathogenic mechanisms leading to chronic HP is needed. We used the Saccharopolyspora rectivirgula (SR) mouse model of HP to determine the extent to which a switch to a Th2-type immune response is associated with chronic HP. Exposure of wild-type (WT) and tlr2/9−/− mice to SR for 14 wk resulted in neutrophilic and lymphocytic alveolitis that was not dependent on Toll-like receptors (TLRs) 2 and 9. Long-term exposure of WT mice to SR resulted in a significant increase in collagen deposition, protein leakage, and IL-1α accompanied by a decrease in quasistatic compliance and total lung capacity compared with unexposed mice. This was associated with an increase in IL-17 but not IL-4 production or recruitment of Th2 cells. tlr2/9−/− mice exhibited an increase in protein leakage but less IL-1α and collagen deposition in the lungs compared with WT mice, yet they still displayed a decrease in quasistatic compliance, although total lung capacity was not affected. These mice exhibited an increase in both IL-13 and IL-17, which suggests that IL-13 may ameliorate some of the lung damage caused by long-term SR exposure. Our results suggest that lung pathology following long-term SR exposure in WT mice is associated with the IL-17 response and that TLRs 2 and 9 may inhibit the development of the IL-13/Th2 response. PMID:26719148

  2. Directing cell migration and organization via nanocrater-patterned cell-repellent interfaces

    NASA Astrophysics Data System (ADS)

    Jeon, Hojeong; Koo, Sangmo; Reese, Willie Mae; Loskill, Peter; Grigoropoulos, Costas P.; Healy, Kevin E.

    2015-09-01

    Although adhesive interactions between cells and nanostructured interfaces have been studied extensively, there is a paucity of data on how nanostructured interfaces repel cells by directing cell migration and cell-colony organization. Here, by using multiphoton ablation lithography to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show that the surfaces altered the cells’ focal-adhesion size and distribution, thus affecting cell morphology, migration and ultimately localization. We also show that nanocrater pitch can disrupt the formation of mature focal adhesions to favour the migration of cells towards higher-pitched regions, which present increased planar area for the formation of stable focal adhesions. Moreover, by designing surfaces with variable pitch but constant nanocrater dimensions, we were able to create circular and striped cellular patterns. Our surface-patterning approach, which does not involve chemical treatments and can be applied to various materials, represents a simple method to control cell behaviour on surfaces.

  3. Activation of Th1 and Tc1 cell adenosine A2A receptors directly inhibits IL-2 secretion in vitro and IL-2-driven expansion in vivo.

    PubMed

    Erdmann, Andreas A; Gao, Zhan-Guo; Jung, Unsu; Foley, Jason; Borenstein, Todd; Jacobson, Kenneth A; Fowler, Daniel H

    2005-06-15

    To evaluate the direct effect of adenosine on cytokine-polarized effector T cells, murine type 1 helper T cells (Th1) and type 1 cytotoxic T lymphocytes (Tc1) and Th2/Tc2 cells were generated using an antigen-presenting cell (APC)-free method. Tc1 and Tc2 cells had similar adenosine signaling, as measured by intracellular cyclic AMP (cAMP) increase upon adenosine A(2A) receptor agonism by CGS21680 (CGS). CGS greatly reduced Tc1 and Tc2 cell interleukin 2 (IL-2) and tumor necrosis factor alpha (TNF-alpha) secretion, with nominal effect on interferon gamma (IFN-gamma) secretion. Tc2 cell IL-4 and IL-5 secretion was not reduced by CGS, and IL-10 secretion was moderately reduced. Agonist-mediated inhibition of IL-2 and TNF-alpha secretion occurred via A(2A) receptors, with no involvement of A(1), A(2B), or A(3) receptors. Adenosine agonist concentrations that abrogated cytokine secretion did not inhibit Tc1 or Tc2 cell cytolytic function. Adenosine modulated effector T cells in vivo, as CGS administration reduced CD4(+)Th1 and CD8(+)Tc1 cell expansion to alloantigen and, in a separate model, reduced antigen-specific CD4(+) Th1 cell numbers. Remarkably, agonist-mediated T-cell inhibition was abrogated by in vivo IL-2 therapy. Adenosine receptor activation therefore preferentially inhibits type I cytokine secretion, most notably IL-2. Modulation of adenosine receptors may thus represent a suitable target primarily for inflammatory conditions mediated by Th1 and Tc1 cells.

  4. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    SciTech Connect

    Li, Wen-Zhong; Ai, Zhi-Ying; Wang, Zhi-Wei; Chen, Lin-Lin; Guo, Ze-Kun; Zhang, Yong

    2015-09-25

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog.

  5. Bi-directional electrical characterisation of microbial fuel cell.

    PubMed

    Degrenne, N; Ledezma, P; Bevilacqua, P; Buret, F; Allard, B; Greenman, J; Ieropoulos, I A

    2013-01-01

    The electrical performance of microbial fuel cells in steady-state is usually investigated by standard characterisation methods that reveal many important parameters e.g. maximum power. This paper introduces a novel "bi-directional" method to study how the acquisition parameters (i.e. sweep rate and sweep regime) can influence measurements and consequently performance estimations. The investigation exhibited considerable differences (hysteresis) between the forward and backward characterisation regimes, indicating a difficulty to reach steady-state under certain conditions. Moreover, it is found that fast sweep rates (time-step of 2 min) can lead to an overestimation of the short-circuit currents, while prolonged operation with high external loads leads to maximum power overestimation and extended conditioning at high currents can result in its underestimation.

  6. Thin Film Catalyst Layers for Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Witham, C. K.; Chun, W.; Ruiz, R.; Valdez, T. I.; Narayanan, S. R.

    2000-01-01

    One of the primary obstacles to the widespread use of the direct methanol fuel cell (DMFC) is the high cost of the catalyst. Therefore, reducing the catalyst loading well below the current level of 8-12 mg/cm 2 would be important to commercialization. The current methods for preparation of catalyst layers consisting of catalyst, ionomer and sometimes a hydrophobic additive are applied by either painting, spraying, decal transfer or screen printing processes. Sputter deposition is a coating technique widely used in manufacturing and therefore particularly attractive. In this study we have begun to explore sputtering as a method for catalyst deposition. Present experiments focus on Pt-Ru catalyst layers for the anode.

  7. Surface modification of carbon fuels for direct carbon fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Zhu, Zhonghua; Chen, Jiuling; De Marco, Roland; Dicks, Andrew; Bradley, John; Lu, Gaoqing

    The direct carbon fuel cell (DCFC) is a promising power-generation device that has much higher efficiency (80%) and less emissions than conventional coal-fired power plants. Two commercial carbons (activated carbon and carbon black) pre-treated with HNO 3, HCl or air plasma are tested in a DCFC. The correlation between the surface properties and electrochemical performance of the carbon fuels is explored. The HNO 3-treated carbon fuels have the highest electrochemical reactivity in the DCFC due to the largest degree of surface oxygen functional groups. The overall effect on changing the electrochemical reactivity of carbon fuels is in the order HNO 3 > air plasma ≈ HCl. Product gas analysis indicates that complete oxidation of carbon to CO 2 can be achieved at 600-700 °C.

  8. Direct Adaptive Aircraft Control Using Dynamic Cell Structure Neural Networks

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles C.

    1997-01-01

    A Dynamic Cell Structure (DCS) Neural Network was developed which learns topology representing networks (TRNS) of F-15 aircraft aerodynamic stability and control derivatives. The network is integrated into a direct adaptive tracking controller. The combination produces a robust adaptive architecture capable of handling multiple accident and off- nominal flight scenarios. This paper describes the DCS network and modifications to the parameter estimation procedure. The work represents one step towards an integrated real-time reconfiguration control architecture for rapid prototyping of new aircraft designs. Performance was evaluated using three off-line benchmarks and on-line nonlinear Virtual Reality simulation. Flight control was evaluated under scenarios including differential stabilator lock, soft sensor failure, control and stability derivative variations, and air turbulence.

  9. Influence of Th2 Cytokines on the Cornified Envelope, Tight Junction Proteins, and ß-Defensins in Filaggrin-Deficient Skin Equivalents.

    PubMed

    Hönzke, Stefan; Wallmeyer, Leonie; Ostrowski, Anja; Radbruch, Moritz; Mundhenk, Lars; Schäfer-Korting, Monika; Hedtrich, Sarah

    2016-03-01

    Atopic dermatitis is a chronic skin condition with complex etiology. It is characterized by skin barrier defects and T helper type 2 (Th2)-polarized inflammation. Although mutations in the filaggrin gene are known to be prominent genetic risk factors for the development of atopic dermatitis, the interdependency between these and an altered cytokine milieu is not fully understood. In this study, we evaluated the direct effects of filaggrin deficiency on the cornified envelope, tight junction proteins, and innate immune response, and report the effects of Th2 cytokines in normal and filaggrin-deficient skin equivalents. Supplementation with IL-4 and IL-13 led to distinct histologic changes and significantly increased skin surface pH, both of which were enhanced in filaggrin knockdown skin equivalents. We detected a compensatory up-regulation of involucrin and occludin in filaggrin-deficient skin that was dramatically disturbed when simultaneous inflammation occurred. Furthermore, we found that a lack of filaggrin triggered an up-regulation of human ?-defensin 2 via an unknown mechanism, which was abolished by Th2 cytokine supplementation. Taken together, these results indicate that defects in the epidermal barrier, skin permeability, and cutaneous innate immune response are not primarily linked to filaggrin deficiency but are rather secondarily induced by Th2 inflammation.

  10. Low direct cytotoxicity of nabumetone on gastric mucosal cells.

    PubMed

    Arai, Yasuhiro; Tanaka, Ken-Ichiro; Ushijima, Hironori; Tomisato, Wataru; Tsutsumi, Shinji; Aburaya, Mayuko; Hoshino, Tatsuya; Yokomizo, Kazumi; Suzuki, Keitarou; Katsu, Takashi; Tsuchiya, Tomofusa; Mizushima, Tohru

    2005-09-01

    Prodrugs of non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for clinical purposes because they are not harmful to the gastrointestinal mucosa. We recently showed that NSAIDs have direct cytotoxicity in NSAID-induced gastric lesions. We show here that under conditions where the NSAIDs indomethacin and celecoxib clearly induce cell death, an NSAID prodrug, nabumetone, and its active metabolite 6-methoxy-2-naphthylacetic acid (6MNA), did not have such effects. Moreover, nabumetone and 6MNA exhibited much lower membrane permeabilizing activities than did indomethacin and celecoxib. We recently reported that when an orally administered NSAID was used in combination with a low dose of intravenously administered indomethacin, the severity of gastric lesions produced in rats depended on the cytotoxicity of the orally administered NSAID. Using a similar protocol, we show here that gastric lesions were produced when the orally administered NSAID was celecoxib, but not when nabumetone was used. We thus propose that the low direct cytotoxicity of nabumetone observed in vitro is maintained in vivo, and that the use of nabumetone does not harm the gastric mucosa.

  11. Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

    SciTech Connect

    Fletcher, James H.; Cox, Philip; Harrington, William J; Campbell, Joseph L

    2013-09-03

    ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focused on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel

  12. On the mechanism determining the TH1/TH2 phenotype of an immune response, and its pertinence to strategies for the prevention, and treatment, of certain infectious diseases.

    PubMed

    Bretscher, P A

    2014-06-01

    It is well recognized that the physiological/pathological consequences of an immune response, against a foreign or a self-antigen, are often critically dependent on the class of immunity generated. Here we focus on how antigen interacts with the cells of the immune system to determine whether antigen predominantly generates Th1 or Th2 cells. We refer to this mechanism as the 'decision criterion' controlling the Th1/Th2 phenotype of the immune response. A plausible decision criterion should account for the variables of immunization known to affect the Th1/Th2 phenotype of the ensuing immune response. Documented variables include the nature of the antigen, in terms of its degree of foreignness, the dose of antigen and the time after immunization at which the Th1/Th2 phenotype of the immune response is assessed. These are quantitative variables made at the level of the system. In addition, the route of immunization is also critical. I describe a quantitative hypothesis as to the nature of the decision criterion, referred to as the Threshold Hypothesis. This hypothesis accounts for the quantitative variables of immunization known to affect the Th1/Th2 phenotype of the immune response generated. I suggest and illustrate how this is not true of competing, contemporary hypotheses. I outline studies testing predictions of the hypothesis and illustrate its potential utility in designing strategies to prevent or treat medical situations where a predominant Th1 response is required to contain an infection, such as those caused by HIV-1 and by Mycobacterium tuberculosis, or to contain cancers.

  13. Fabric-based alkaline direct formate microfluidic fuel cells.

    PubMed

    Domalaon, Kryls; Tang, Catherine; Mendez, Alex; Bernal, Franky; Purohit, Krutarth; Pham, Linda; Haan, John; Gomez, Frank A

    2017-01-12

    Fabric-based microfluidic fuel cells (MFCs) serve as a novel, cost-efficient alternative to traditional FCs and batteries, since fluids naturally travel across fabric via capillary action, eliminating the need for an external pump and lowering production and operation costs. Building on previous research with Y-shaped paper-based MFCs, fabric-based MFCs mitigate fragility and durability issues caused by long periods of fuel immersion. In this study, we describe a microfluidic fabric-based direct formate fuel cell, with 5 M potassium formate and 30% hydrogen peroxide as the anode fuel and cathode oxidant, respectively. Using a two-strip, stacked design, the optimized parameters include the type of encasement, the barrier, and the fabric type. Surface contact of the fabric and laminate sheet expedited flow and respective chemical reactions. The maximum current (22.83 mA/cm(2) ) and power (4.40 mW/cm(2) ) densities achieved with a 65% cotton/35% polyester blend material are a respective 8.7% and 32% higher than previous studies with Y-shaped paper-based MFCs. In series configuration, the MFCs generate sufficient energy to power a handheld calculator, a thermometer, and a spectrum of light-emitting diodes.

  14. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    SciTech Connect

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  15. Towards operating direct methanol fuel cells with highly concentrated fuel

    NASA Astrophysics Data System (ADS)

    Zhao, T. S.; Yang, W. W.; Chen, R.; Wu, Q. X.

    A significant advantage of direct methanol fuel cells (DMFCs) is the high specific energy of the liquid fuel, making it particularly suitable for portable and mobile applications. Nevertheless, conventional DMFCs have to be operated with excessively diluted methanol solutions to limit methanol crossover and the detrimental consequences. Operation with diluted methanol solutions significantly reduces the specific energy of the power pack and thereby prevents it from competing with advanced batteries. In view of this fact, there exists a need to improve conventional DMFC system designs, including membrane electrode assemblies and the subsystems for supplying/removing reactants/products, so that both the cell performance and the specific energy can be simultaneously maximized. This article provides a comprehensive review of past efforts on the optimization of DMFC systems that operate with concentrated methanol. Based on the discussion of the key issues associated with transport of the reactants/products, the strategies to manage the supply/removal of the reactants/products in DMFC operating with highly concentrated methanol are identified. With these strategies, the possible approaches to achieving the goal of concentrated fuel operation are then proposed. Past efforts in the management of the reactants/products for implementing each of the approaches are also summarized and reviewed.

  16. Direct fuel cell - A high proficiency power generator for biofuels

    SciTech Connect

    Patel, P.S.; Steinfeld, G.; Baker, B.S.

    1994-12-31

    Conversion of renewable bio-based resources into energy offers significant benefits for our environment and domestic economic activity. It also improves national security by displacing fossil fuels. However, in the current economic environment, it is difficult for biofuel systems to compete with other fossil fuels. The biomass-fired power plants are typically smaller than 50 MW, lower in electrical efficiencies (<25%) and experience greater costs for handling and transporting the biomass. When combined with fuel cells such as the Direct Fuel Cell (DFC), biofuels can produce power more efficiently with negligible environmental impact. Agricultural and other waste biomass can be converted to ethanol or methane-rich biofuels for power generation use in the DFC. These DFC power plants are modular and factory assembled. Due to their electrochemical (non-combustion) conversion process, these plants are environmentally friendly, highly efficient and potentially cost effective, even in sizes as small as a few meagawatts. They can be sited closer to the source of the biomass to minimize handling and transportation costs. The high-grade waste heat available from DFC power plants makes them attractive in cogeneration applications for farming and rural communities. The DFC potentially opens up new markets for biofuels derived from wood, grains and other biomass waste products.

  17. Single cell activity reveals direct electron transfer in methanotrophic consortia

    NASA Astrophysics Data System (ADS)

    McGlynn, Shawn E.; Chadwick, Grayson L.; Kempes, Christopher P.; Orphan, Victoria J.

    2015-10-01

    Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.

  18. A Direct Carbon Fuel Cell with a Molten Antimony Anode

    SciTech Connect

    Jayakumar, Abhimanyu; Kungas, Rainer; Roy, Sounak; Javadekar, Ashay; Buttrey, Douglas J.; Vohs, John M.; Gorte, Raymond J.

    2011-01-01

    The direct utilization of carbonaceous fuels is examined in a solid oxide fuel cell (SOFC) with a molten Sb anode at 973 K. It is demonstrated that the anode operates by oxidation of metallic Sb at the electrolyte interface, with the resulting Sb₂O₃ being reduced by the fuel in a separate step. Although the Nernst Potential for the Sb-Sb₂O₃ mixture is only 0.75 V, the electrode resistance associated with molten Sb is very low, approximately 0.06 Ωcm², so that power densities greater than 350 mW cm⁻² were achieved with an electrolyte-supported cell made from Sc-stabilized zirconia (ScSZ). Temperature programmed reaction measurements of Sb₂O₃ with sugar char, rice starch, carbon black, and graphite showed that the Sb₂O₃ is readily reduced by a range of carbonaceous solids at typical SOFC operating conditions. Finally, stable operation with a power density of 300 mW cm⁻² at a potential of 0.5 V is demonstrated for operation on sugar char.

  19. Dectin-2 Deficiency Promotes Th2 Response and Mucin Production in the Lungs after Pulmonary Infection with Cryptococcus neoformans

    PubMed Central

    Nakamura, Yuri; Sato, Ko; Yamamoto, Hideki; Matsumura, Kana; Matsumoto, Ikumi; Nomura, Toshiki; Miyasaka, Tomomitsu; Ishii, Keiko; Kanno, Emi; Tachi, Masahiro; Yamasaki, Sho; Saijo, Shinobu; Iwakura, Yoichiro

    2014-01-01

    Dectin-2 is a C-type lectin receptor that recognizes high mannose polysaccharides. Cryptococcus neoformans, a yeast-form fungal pathogen, is rich in polysaccharides in its cell wall and capsule. In the present study, we analyzed the role of Dectin-2 in the host defense against C. neoformans infection. In Dectin-2 gene-disrupted (knockout) (Dectin-2KO) mice, the clearance of this fungus and the inflammatory response, as shown by histological analysis and accumulation of leukocytes in infected lungs, were comparable to those in wild-type (WT) mice. The production of type 2 helper T (Th2) cytokines in lungs was higher in Dectin-2KO mice than in WT mice after infection, whereas there was no difference in the levels of production of Th1, Th17, and proinflammatory cytokines between these mice. Mucin production was significantly increased in Dectin-2KO mice, and this increase was reversed by administration of anti-interleukin 4 (IL-4) monoclonal antibody (MAb). The levels of expression of β1-defensin, cathelicidin, surfactant protein A (Sp-A), and Sp-D in infected lungs were comparable between these mice. In in vitro experiments, IL-12p40 and tumor necrosis factor alpha (TNF-α) production and expression of CD86 and major histocompatibility complex (MHC) class II by bone marrow-derived dendritic cells and alveolar macrophages were completely abrogated in Dectin-2KO mice. Finally, the disrupted lysates of C. neoformans, but not of whole yeast cells, activated Dectin-2-triggered signaling in an assay with nuclear factor of activated T cells (NFAT)-green fluorescent protein (GFP) reporter cells expressing this receptor. These results suggest that Dectin-2 may oppose the Th2 response and IL-4-dependent mucin production in the lungs after infection with C. neoformans, and it may not be required for the production of Th1, Th17, and proinflammatory cytokines or for clearance of this fungal pathogen. PMID:25422263

  20. Improved Cathode Structure for a Direct Methanol Fuel Cell

    NASA Technical Reports Server (NTRS)

    Valdez, Thomas; Narayanan, Sekharipuram

    2005-01-01

    An improved cathode structure on a membrane/electrode assembly has been developed for a direct methanol fuel cell, in a continuing effort to realize practical power systems containing such fuel cells. This cathode structure is intended particularly to afford better cell performance at a low airflow rate. A membrane/electrode assembly of the type for which the improved cathode structure was developed (see Figure 1) is fabricated in a process that includes brush painting and spray coating of catalyst layers onto a polymer-electrolyte membrane and onto gas-diffusion backings that also act as current collectors. The aforementioned layers are then dried and hot-pressed together. When completed, the membrane/electrode assembly contains (1) an anode containing a fine metal black of Pt/Ru alloy, (2) a membrane made of Nafion 117 or equivalent (a perfluorosulfonic acid-based hydrophilic, proton-conducting ion-exchange polymer), (3) a cathode structure (in the present case, the improved cathode structure described below), and (4) the electrically conductive gas-diffusion backing layers, which are made of Toray 060(TradeMark)(or equivalent) carbon paper containing between 5 and 6 weight percent of poly(tetrafluoroethylene). The need for an improved cathode structure arises for the following reasons: In the design and operation of a fuel-cell power system, the airflow rate is a critical parameter that determines the overall efficiency, cell voltage, and power density. It is desirable to operate at a low airflow rate in order to obtain thermal and water balance and to minimize the size and mass of the system. The performances of membrane/electrode assemblies of prior design are limited at low airflow rates. Methanol crossover increases the required airflow rate. Hence, one way to reduce the required airflow rate is to reduce the effect of methanol crossover. Improvement of the cathode structure - in particular, addition of hydrophobic particles to the cathode - has been

  1. Serum Cytokines Th1, Th2, and Th17 Expression Profiling in Active Lupus Nephritis-IV: From a Southern Chinese Han Population

    PubMed Central

    Wang, Yin; Hu, Weiping; Wang, Ning; Sun, Qingyi; Liu, Qingyan; Liu, Xiaocong; Hou, Xianghua; Cheng, Ao

    2016-01-01

    Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by aberrant T cell immune response. Diffuse proliferative lupus nephritis (LN-IV) is the most common, severe, and active form of lupus nephritis. In this study, we investigated the production of Th1, Th2, and Th17 cytokines in prediction of active form of LN-IV. ProcartaPlex multiplex immunoassays panels were used for detection of serum Th1, Th2, and Th17 cytokines profiling. Th1 and Th17 cytokines (IL-18, IFN-γ, IL-12p70, IL-6, and IL-17A) were considerably expressed in the serum of lupus nephritis IV patients in comparison to the healthy control. However, only IL18 and IL6 were higher in class IV versus class III lupus nephritis. Importantly, the ratios of Th1/Th2 (IL-18/IL-4) and Th17/Th2 (IL-17A/IL-4) were significantly elevated in LN-IV when compared with LN-III, LN-V, and healthy controls. Consistently, the serum cytokines IL-18, IL-17A, and IFN-γ were markedly expressed in LN-IV patient glomeruli and interstitial tissue compared to other classes of LN by IHC. ROC further suggests that IL-18 was a potential marker for LN-IV. The data from our study suggests that the early detection and quantification of these cytokines may help in prediction of active form of LN-IV. PMID:27738386

  2. Direct glycerol fuel cell with polytetrafluoroethylene (PTFE) thin film separator

    DOE PAGES

    Benipal, Neeva; Qi, Ji; Gentile, Jacob C.; ...

    2017-01-04

    Here, anion-exchange membrane-based direct glycerol fuel cells (AEM-DGFCs) can yield high power density, however challenges exist in developing chemically stable AEMs. Here, we demonstrate a porous PTFE thin film, a well-known chemical, electro-chemical, and thermal robust material that can serve as a separator between anode and cathode, thus achieving high DGFC’s performance. A simple aqueous-phase reduction method was used to prepare carbon nanotube supported PdAg nanoparticles (PdAg/CNT) with an average particle size of 2.9 nm. A DGFC using a PTFE thin film without any further modification with PdAg/CNT anode catalyst exhibits a peak power density of 214.7 mW cm–2 atmore » 80 °C, about 22.6% lower than a DGFC using a state-of-the-art AEM. We report a 5.8% decrease and 11.1% decrease in cell voltage for a PTFE thin film and AEM; similarly, the cell voltage degradation rate decreases from 1.2 to 0.8 mV h–1 for PTFE thin film, while for AEM, it decreases from 9.6 to 3.0 mV h–1 over an 80 h durability test period. Transmission electron microscopy results indicate that the average particle size of PdAg/CNT increases from 2.9 to 3.7 nm after 80 h discharge; this suggests that PdAg particle growth may be the main reason for the performance drop.« less

  3. Novel APC-like properties of human NK cells directly regulate T cell activation

    PubMed Central

    Hanna, Jacob; Gonen-Gross, Tsufit; Fitchett, Jonathan; Rowe, Tony; Daniels, Mark; Arnon, Tal I.; Gazit, Roi; Joseph, Aviva; Schjetne, Karoline W.; Steinle, Alexander; Porgador, Angel; Mevorach, Dror; Goldman-Wohl, Debra; Yagel, Simcha; LaBarre, Michael J.; Buckner, Jane H.; Mandelboim, Ofer

    2004-01-01

    Initiation of the adaptive immune response is dependent on the priming of naive T cells by APCs. Proteomic analysis of unactivated and activated human NK cell membrane–enriched fractions demonstrated that activated NK cells can efficiently stimulate T cells, since they upregulate MHC class II molecules and multiple ligands for TCR costimulatory molecules. Furthermore, by manipulating antigen administration, we show that NK cells possess multiple independent unique pathways for antigen uptake. These results highlight NK cell–mediated cytotoxicity and specific ligand recognition by cell surface–activating receptors on NK cells as unique mechanisms for antigen capturing and presentation. In addition, we analyzed the T cell–activating potential of human NK cells derived from different clinical conditions, such as inflamed tonsils and noninfected and CMV-infected uterine decidual samples, and from transporter-associated processing antigen 2–deficient patients. This in vivo analysis revealed that proinflammatory, but not immune-suppressive, microenvironmental requirements can selectively dictate upregulation of T cell–activating molecules on NK cells. Taken together, these observations offer new and unexpected insights into the direct interactions between NK and T cells and suggest novel APC-like activating functions for human NK cells. PMID:15578093

  4. Infectious rotavirus enters cells by direct cell membrane penetration, not by endocytosis

    SciTech Connect

    Kaljot, K.T.; Shaw, R.D.; Greenberg, H.B. Palo Alto Veterans Administration Medical Center, CA ); Rubin, D.H. )

    1988-04-01

    Rotaviruses are icosahedral viruses with a segmented, double-stranded RNA genome. They are the major cause of severe infantile infectious diarrhea. Rotavirus growth in tissue culture is markedly enhanced by pretreatment of virus with trypsin. Trypsin activation is associated with cleavage of the viral hemagglutinin (viral protein 3 (VP3); 88 kilodaltons) into two fragments (60 and 28 kilodaltons). The mechanism by which proteolytic cleavage leads to enhanced growth is unknown. To determine whether trypsin treatment affected rotavirus internalization, the authors studied the kinetics of entry of infectious rhesus rotavirus (RRV) into MA104 cells. Trypsin-activated RRV was internalized with a half-time of 3 to 5 min, while nonactivated virus disappeared from the cell surface with a half-time of 30 to 50 min. In contrast to trypsin-activated RRV, loss of nonactivated RRV from the cell surface did not result in the appearance of infection, as measured by plaque formation. Purified trypsin-activated RRV added to cell monolayers at pH 7.4 mediated {sup 51}Cr, ({sup 14}C)choline, and ({sup 3}H)inositol released from prelabeled MA104 cells. This release could be specifically blocked by neutralizing antibodies to VP3. These results suggest that MA104 cell infection follows the rapid entry of trypsin-activated RRV by direct cell membrane penetration. Cell membrane penetration of infectious RRV is initiated by trypsin cleavage of VP3. Neutralizing antibodies can inhibit this direct membrane penetration.

  5. A nematode immunomodulator suppresses grass pollen-specific allergic responses by controlling excessive Th2 inflammation.

    PubMed

    Daniłowicz-Luebert, Emilia; Steinfelder, Svenja; Kühl, Anja A; Drozdenko, Gennadiy; Lucius, Richard; Worm, Margitta; Hamelmann, Eckard; Hartmann, Susanne

    2013-03-01

    Helminth parasites modulate the immune system by complex mechanisms to ensure persistence in the host. Released immunomodulatory parasite components lead to a beneficial environment for the parasite by targeting different host cells and in parallel to a modulation of unrelated inflammatory responses in the host, such as allergy. The aim of this study was to investigate the effect of the potent helminth immunomodulator, filarial cystatin, in a murine model of airway inflammation and hyperreactivity induced by a clinically relevant aeroallergen (timothy grass (Phleum pratense) pollen) and on the function of peripheral blood mononuclear cells (PBMCs) from timothy grass pollen allergic patients. BALB/c mice were systemically sensitised with a recombinant major allergen of timothy grass pollen (rPhl p 5b) and then challenged with timothy grass pollen extract (GPE) via the airways. Filarial cystatin was applied i.p. during the sensitisation phase. Airway hyperresponsiveness to methacholine challenges, inflammation of airways, inflammatory cell recruitment, cytokine production and lung histopathology were investigated. In a translational approach, PBMCs from allergic subjects and healthy controls were treated in vitro with cystatin prior to stimulation with GPE. Administration of filarial cystatin suppressed rPhl p 5b-induced allergen-specific Th2-responses and airway inflammation, inhibited local recruitment of eosinophils, reduced levels of allergen-specific IgE and down-regulated IL-5 and IL-13 in the bronchoalveolar lavage (BAL). Ex vivo restimulation with cystatin of spleen cells from cystatin-treated mice induced the production of IL-10, while cystatin inhibited allergen-specific IL-5 and IL-13 levels. Human PBMCs from timothy grass pollen allergic patients displayed a shift towards a Th1 response after treatment with cystatin. These results show that filarial cystatin ameliorates allergic inflammation and disease in a clinically relevant model of allergy. This data

  6. Inducible costimulatory molecule deficiency induced imbalance of Treg and Th17/Th2 delays rejection reaction in mice undergoing allogeneic tracheal transplantation

    PubMed Central

    Xu, Jingsong; Wu, Yu; Wang, Guifang; Qin, Yanghua; Zhu, Li; Tang, Gusheng; Shen, Qian

    2014-01-01

    Objective: This study aimed to investigate the role of inducible costimulatory molecule (ICOS) pathway in the rejection reaction of mice undergoing allogeneic tracheal transplantation. Methods: The bronchus was separated from wide-type (WT) BalB/c mice and transplanted into WT BalB/c mice, C57 mice and icos-/- mice to prepare the obliterative bronchiolitis (OB) animal model. The transplanted bronchus was pathologically examined; flow cytometry was done to detect the T cell subsets and activity of the bronchus and spleen of recipient mice. Results: 21 d after transplantation, evident rejection reaction was observed and the proportion of Th2 and Th17 cells increased significantly in the bronchus and spleen in C57 mice receiving allogeneic tracheal transplantation when compared with mice with autologous transplantation, but the proportion of Treg cells was comparable between them. When compared with WT BalB/c mice, the proportion of Th2, Th17 and Treg cells reduced markedly and rejection reaction was attenuated in icos-/- mice receiving tracheal transplantation, although rejection reaction was still noted. Conclusion: icos knockout may delay the rejection reaction after tracheal transplantation, which might be ascribed to the imbalance among Th2, Th17 and Treg cells. PMID:25628788

  7. Amelioration of skewed Th1/Th2 balance in tumor-bearing and asthma-induced mice by oral administration of Agaricus blazei extracts.

    PubMed

    Takimoto, Hiroaki; Kato, Hanano; Kaneko, Masahiro; Kumazawa, Yoshio

    2008-01-01

    We showed in a previous study that hot-water extracts of Agaricus blazei (Agaricus extracts) had anti-tumor activity to Meth A fibrosarcoma, but it remains unclear whether the Agaricus extracts ameliorate the skewed balance of type-1 T helper (Th1) and type-2 T helper (Th2) cells. We examined whether Agaricus extracts effect the skewed Th1/Th2 balance in tumor-bearing and asthma-induced mice. When Meth A-bearing mice were given orally either Agaricus extracts or water once a day starting 5 days after tumor implantation, spleen T cells, prepared from tumor-bearing mice treated with Agaricus extracts, in response to anti-CD3 monoclonal antibody produced significantly higher levels of interferon gamma (IFN-gamma) than that of controls. The mRNA expression of IFN-gamma-inducing protein 10 and the frequency of CD69(+) or CD49d(+) cells, among activated T cells infiltrated into tumors, significantly increased in Agaricus-treated mice, compared with those of tumor-controls. In asthma-induced mice, treatment with the Agaricus extracts caused significant downregulation of OVA-specific antibody responses of IgG1 and IgE but not of IgG2a, and significantly decreased total cell numbers, levels of interleukin 5, and eosinophil numbers in bronchial alveolar lavage fluids. IFN-gamma production by anti-CD3-stimulated spleen cells, obtained from Agaricus-treated mice, significantly increased. Our results strongly suggest that oral administration of Agaricus extracts ameliorates the Th1/Th2 balance from the Th2-skewed conditions.

  8. Increased hepatic Th2 and Treg subsets are associated with biliary fibrosis in different strains of mice caused by Clonorchis sinensis

    PubMed Central

    Fang, Fan; Du, Ying; Ma, Rui; Li, Xiang-Yang; Yu, Qian; Meng, Di; Tang, Ren-Xian; Zheng, Kui-Yang

    2017-01-01

    Previous studies showed that CD4+T cells responses might be involved in the process of biliary fibrosis. However, the underlying mechanism resulting in biliary fibrosis caused by Clonorchis sinensis remains not yet fully elucidated. The objectives of the present study were to investigate the different profiles of hepatic CD4+T cell subsets (Th1, Th2, Th17 and Treg cells) and their possible roles in the biliary fibrosis of different strains of mice (C57BL/6, BALB/c and FVB mice) induced by C. sinensis infection. C57BL/6, BALB/c and FVB mice were orally gavaged with 45 metacercariae. All mice were sacrificed on 28 days post infection in deep anesthesia conditions. The leukocytes in the liver were separated to examine CD4+T cell subsets by flow cytometry and the left lobe of liver was used to observe pathological changes, collagen depositions and the concentrations of hydroxyproline. The most serious cystic and fibrotic changes appeared in FVB infected mice indicated by gross observation, Masson’s trichrome staining and hydroxyproline content detection. In contrast to C57BL/6 infected mice, diffuse nodules and more intensive fibrosis were observed in the BALB/c infected mice. No differences of the hepatic Th1 subset and Th17 subset were found among the three strains, but the hepatic Th2 and Treg cells and their relative cytokines were dramatically increased in the BALB/c and FVB infected groups compared with the C57BL/6 infected group (P<0.01). Importantly, increased Th2 subset and Treg subset all positively correlated with hydroxyproline contents (P<0.01). This result for the first time implied that the increased hepatic Th2 and Treg cell subsets were likely to play potential roles in the formation of biliary fibrosis in C. sinensis-infected mice. PMID:28151995

  9. The direct effect of estrogen on cell viability and apoptosis in human gastric cancer cells.

    PubMed

    Qin, Jian; Liu, Min; Ding, Qianshan; Ji, Xiang; Hao, Yarong; Wu, Xiaomin; Xiong, Jie

    2014-10-01

    Epidemiology researches indicated that gastric cancer is a male-predominant disease; both expression level of estrogen and expression pattern of estrogen receptors (ERs) influence its carcinogenesis. But the direct effect of estrogen on gastric cancer cells is still unclear. This study aimed to explore the direct effect of β-estradiol (E2) on gastric cancer cells. SGC7901 and BGC823 were treated with a serial of concentrations of E2. The survival rates of both the cell lines were significantly reduced, and the reduction of viability was due to apoptosis triggered by E2 treatment. Caspase 3 was activated in response to the increasing E2 concentration in both SGC7901 and BGC823. Cleaved Caspase 3 fragments were detected, and the expression levels of Bcl-2 and Bcl-xL were reduced. Apoptosis was further confirmed by flow cytometry. The expression level of PEG10, an androgen receptor target gene, was reduced during E2 treatment. Both ERα and ERβ were expressed in these cell lines, and the result of bioinformatics analysis of gastric cancer from GEO datasets indicated that the expression levels of both ERα and ERβ were significantly higher in noncancerous gastric tissues than in gastric cancer tissues. Our research indicated that estrogen can reduce cell viability and promote apoptosis in gastric cancer cells directly; ERs expression level is associated with gastric cancer. Our research will help to understand the mechanism of gender disparity in gastric cancer.

  10. Early Activation of Th2/Th22 Inflammatory and Pruritogenic Pathways in Acute Canine Atopic Dermatitis Skin Lesions.

    PubMed

    Olivry, Thierry; Mayhew, David; Paps, Judy S; Linder, Keith E; Peredo, Carlos; Rajpal, Deepak; Hofland, Hans; Cote-Sierra, Javier

    2016-10-01

    Determining inflammation and itch pathway activation in patients with atopic dermatitis (AD) is fraught with the inability to precisely assess the age of skin lesions, thus affecting the analysis of time-dependent mediators. To characterize inflammatory events occurring during early experimental acute AD lesions, biopsy samples were collected 6, 24, and 48 hours after epicutaneous application of Dermatophagoides farinae house dust mites to sensitized atopic dogs. The skin transcriptome was assessed using a dog-specific microarray and quantitative PCR. Acute canine AD skin lesions had a significant up-regulation of genes encoding T helper (Th) 2 (e.g., IL4, IL5, IL13, IL31, and IL33), Th9 (IL9), and Th22 (IL22) cytokines as well as Th2-promoting chemokines such as CCL5 and CCL17. Proinflammatory (e.g., IL6, LTB, and IL18) cytokines were also up-regulated. Other known pruritogenic pathways were also activated: there was significant up-regulation of genes encoding proteases cathepsin S (CTSS), mast cell chymase (CMA1), tryptase (TPS1) and mastin, neuromedin-B (NMB), nerve growth factor (NGF), and leukotriene-synthesis enzymes (ALOX5, ALOX5AP, and LTA4H). Experimental acute canine house dust mite-induced AD lesions exhibit an activation of innate and adaptive immune responses and pruritogenic pathways similar to those seen in humans with acute AD, thereby validating this model to test innovative therapeutics modalities for this disease.

  11. The progesterone derivative dydrogesterone abrogates murine stress-triggered abortion by inducing a Th2 biased local immune response.

    PubMed

    Joachim, Ricarda; Zenclussen, Ana Claudia; Polgar, Beata; Douglas, Alison J; Fest, Stefan; Knackstedt, Maike; Klapp, Burghard F; Arck, Petra Clara

    2003-11-01

    Stress is known to induce abortions in mice and humans, putatively via increased levels of abortogenic Th1 cytokines and a decrease of progesterone. Adequate levels of progesterone exert an antiabortive response through binding to the progesterone-receptor, which induces the release of progesterone-induced blocking factor (PIBF) from lymphocytes. PIBF is highly pregnancy-protective by induction of a Th2 biased immune activity. The aim of this study was to investigate the effect of the progesterone derivative dydrogesterone (6-dehydro-retroprogesterone) in stress-triggered murine abortion. DBA/2J-mated CBA/J female mice were randomized in different groups: two groups were treated with different dydrogesterone dosages in a single injection before exposure to sound stress on Day 5 of pregnancy, one group was exposed to stress without dydrogesterone treatment, the fourth group received no stress and no dydrogesterone. On gestation Day 13, a highly elevated abortion rate was detected in stressed mice compared to control mice. Stressed animals presented lower levels of progesterone and PIBF in plasma and a reduced staining intensity of progesterone receptor at the feto-maternal interface. Injection of dydrogesterone abrogated the effect of stress on the abortion rate. Further, dydrogesterone increased levels of plasma PIBF in stressed mice, but did not affect progesterone levels. Interestingly, dydrogesterone dramatically increased the percentage of IL-4 positive decidual immune cells in stressed mice. Our data suggest that dydrogesterone abrogates stress-triggered abortion by inducing a Th2 biased local immune response.

  12. Endothelial cells direct mesenchymal stem cells toward a smooth muscle cell fate.

    PubMed

    Lin, Cho-Hao; Lilly, Brenda

    2014-11-01

    Under defined conditions, mesenchymal stem cells can differentiate into unique cell types, making them attractive candidates for cell-based disease therapies. Ischemic diseases would greatly benefit from treatments that include the formation of new blood vessels from mesenchymal stem cells. However, blood vessels are complex structures composed of endothelial cells and smooth muscle cells, and their assembly and function in a diseased environment is reliant upon joining with the pre-existing vasculature. Although endothelial cell/smooth muscle cell interactions are well known, how endothelial cells may influence mesenchymal stem cells and facilitate their differentiation has not been defined. Therefore, we sought to explore how endothelial cells might drive mesenchymal stem cells toward a smooth muscle fate. Our data show that cocultured endothelial cells induce smooth muscle cell differentiation in mesenchymal stem cells. Endothelial cells can promote a contractile phenotype, reduce proliferation, and enhance collagen synthesis and secretion. Our data show that Notch signaling is essential for endothelial cell-dependent differentiation, and this differentiation pathway is largely independent of growth factor signaling mechanisms.

  13. Direct fuel cell power plants: the final steps to commercialization

    NASA Astrophysics Data System (ADS)

    Glenn, Donald R.

    Since the last paper presented at the Second Grove Fuel Cell Symposium, the Energy Research Corporation (ERC) has established two commercial subsidiaries, become a publically-held firm, expanded its facilities and has moved the direct fuel cell (DFC) technology and systems significantly closer to commercial readiness. The subsidiaries, the Fuel Cell Engineering Corporation (FCE) and Fuel Cell Manufacturing Corporation (FCMC) are perfecting their respective roles in the company's strategy to commercialize its DFC technology. FCE is the prime contractor for the Santa Clara Demonstration and is establishing the needed marketing, sales, engineering, and servicing functions. FCMC in addition to producing the stacks and stack modules for the Santa Clara demonstration plant is now upgrading its production capability and product yields, and retooling for the final stack scale-up for the commercial unit. ERC has built and operated the tallest and largest capacities-to-date carbonate fuel cell stacks as well as numerous short stacks. While most of these units were tested at ERC's Danbury, Connecticut (USA) R&D Center, others have been evaluated at other domestic and overseas facilities using a variety of fuels. ERC has supplied stacks to Elkraft and MTU for tests with natural gas, and RWE in Germany where coal-derived gas were used. Additional stack test activities have been performed by MELCO and Sanyo in Japan. Information from some of these activities is protected by ERC's license arrangements with these firms. However, permission for limited data releases will be requested to provide the Grove Conference with up-to-date results. Arguably the most dramatic demonstration of carbonate fuel cells in the utility-scale, 2 MW power plant demonstration unit, located in the City of Santa Clara, California. Construction of the unit's balance-of-plant (BOP) has been completed and the installed equipment has been operationally checked. Two of the four DFC stack sub-modules, each

  14. Cytokine polymorphisms in Th1/Th2 pathway genes, body mass index, and risk of non-Hodgkin lymphoma.

    PubMed

    Chen, Yingtai; Zheng, Tongzhang; Lan, Qing; Foss, Francine; Kim, Christopher; Chen, Xuezhong; Dai, Min; Li, Yumin; Holford, Theodore; Leaderer, Brian; Boyle, Peter; Chanock, Stephen J; Rothman, Nathaniel; Zhang, Yawei

    2011-01-13

    We conducted a population-based, case-control study in Connecticut women to test the hypothesis that genetic variations in Th1 and Th2 cytokine genes modify the relationship between body mass index (BMI) and risk of non-Hodgkin lymphoma (NHL). Compared with those with BMI less than 25 kg/m(2), women with BMI more than or equal to 25 kg/m(2) had 50% to 90% increased risk of NHL among women who carried IFNGR2 (rs9808753) AA, IL5 (rs2069812) CT/TT, IL7R (rs1494555) AA, and TNF (rs1799724) CC genotypes, but no increased risk among women with IFNGR2 AG/GG, IL5 CC, IL7R AG/GG, and TNF CT/TT genotypes. A significant interaction with BMI was only observed for IFNGR2 (rs9808753 P(forinteraction) = .034) and IL7R (rs1494555 P(forinteraction) = .016) for NHL overall; IL7R (rs1494555 P(forinteraction) = .016) and TNF (1799724 P(forinteraction) = .031) for B-cell lymphoma; and IL5 (rs2069812 P(forinteraction) = .034) for T-cell lymphoma. After stratification by common B-cell lymphoma subtypes, a significant interaction was observed for IFNGR2 (rs9808753 P(forinteraction) = .006), IL13 (rs20541 P(forinteraction) = .019), and IL7R (rs1494555 P(forinteraction) = .012) for marginal zone B-cell lymphoma; IL7R (rs1494555 P(forinteraction) = .017) for small lymphocytic lymphoma/chronic lymphocytic leukemia; and IL12A (rs568408 P(forinteraction) = .013) and TNF (1799724 P(forinteraction) = .04) for follicular lymphoma. The results suggest that common genetic variation in Th1/Th2 pathway genes may modify the association between BMI and NHL risk.

  15. A goal-directed spatial navigation model using forward trajectory planning based on grid cells.

    PubMed

    Erdem, Uğur M; Hasselmo, Michael

    2012-03-01

    A goal-directed navigation model is proposed based on forward linear look-ahead probe of trajectories in a network of head direction cells, grid cells, place cells and prefrontal cortex (PFC) cells. The model allows selection of new goal-directed trajectories. In a novel environment, the virtual rat incrementally creates a map composed of place cells and PFC cells by random exploration. After exploration, the rat retrieves memory of the goal location, picks its next movement direction by forward linear look-ahead probe of trajectories in several candidate directions while stationary in one location, and finds the one activating PFC cells with the highest reward signal. Each probe direction involves activation of a static pattern of head direction cells to drive an interference model of grid cells to update their phases in a specific direction. The updating of grid cell spiking drives place cells along the probed look-ahead trajectory similar to the forward replay during waking seen in place cell recordings. Directions are probed until the look-ahead trajectory activates the reward signal and the corresponding direction is used to guide goal-finding behavior. We report simulation results in several mazes with and without barriers. Navigation with barriers requires a PFC map topology based on the temporal vicinity of visited place cells and a reward signal diffusion process. The interaction of the forward linear look-ahead trajectory probes with the reward diffusion allows discovery of never-before experienced shortcuts towards a goal location.

  16. Left–right asymmetric cell intercalation drives directional collective cell movement in epithelial morphogenesis

    PubMed Central

    Sato, Katsuhiko; Hiraiwa, Tetsuya; Maekawa, Emi; Isomura, Ayako; Shibata, Tatsuo; Kuranaga, Erina

    2015-01-01

    Morphogenetic epithelial movement occurs during embryogenesis and drives complex tissue formation. However, how epithelial cells coordinate their unidirectional movement while maintaining epithelial integrity is unclear. Here we propose a novel mechanism for collective epithelial cell movement based on Drosophila genitalia rotation, in which epithelial tissue rotates clockwise around the genitalia. We found that this cell movement occurs autonomously and requires myosin II. The moving cells exhibit repeated left–right-biased junction remodelling, while maintaining adhesion with their neighbours, in association with a polarized myosin II distribution. Reducing myosinID, known to cause counter-clockwise epithelial-tissue movement, reverses the myosin II distribution. Numerical simulations revealed that a left–right asymmetry in cell intercalation is sufficient to induce unidirectional cellular movement. The cellular movement direction is also associated with planar cell-shape chirality. These findings support a model in which left–right asymmetric cell intercalation within an epithelial sheet drives collective cellular movement in the same direction. PMID:26656655

  17. Nano-Engineered Catalysts for Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Myung, Nosang; Narayanan, Sekharipuram; Wiberg, Dean

    2008-01-01

    Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity. The present method involves electrodeposition of one or more catalytic metal(s) or a catalytic-metal/polytetrafluoroethylene nanocomposite on an alumina nanotemplate. The alumina nanotemplate is then dissolved, leaving the desired metal or metal/polytetrafluoroethylene-composite catalyst layer. Unlike some prior methods of making fine metal catalysts, this method does not involve processing at elevated temperature; all processing can be done at room temperature. In addition, this method involves fewer steps and is more amenable to scaling up for mass production. Alumina nanotemplates are porous alumina membranes that have been fabricated, variously, by anodizing either pure aluminum or aluminum that has been deposited on silicon by electronbeam evaporation. The diameters of the pores (7 to 300 nm), areal densities of pores (as much as 7 x 10(exp 10)sq cm), and lengths of pores (up to about 100 nm) can be tailored by selection of fabrication conditions. In a given case, the catalytic metal, catalytic metal alloy, or catalytic metal/ polytetrafluoroethylene composite is electrodeposited in the pores of the alumina nanotemplate. The dimensions of the pores, together with the electrodeposition conditions

  18. Topical azithromycin and clarithromycin inhibit acute and chronic skin inflammation in sensitized mice, with apparent selectivity for Th2-mediated processes in delayed-type hypersensitivity.

    PubMed

    Ivetić Tkalčević, Vanesa; Cužić, Snježana; Kramarić, Miroslava Dominis; Parnham, Michael J; Eraković Haber, Vesna

    2012-02-01

    Macrolide antibiotics inhibit the secretion of Th1 cytokines while their effects on the release of Th2 cytokines are variable. We investigated molecular and cellular markers of Th1- and Th2-mediated inflammatory mechanisms and the anti-inflammatory activity of azithromycin and clarithromycin in phorbol 12-myristate 13-acetate (PMA) and oxazolone (OXA)-induced skin inflammation. Dexamethasone (50 μg/ear), azithromycin, and clarithromycin (500 μg/ear) reduced TNF-α and interleukin (IL)-1β concentration in ear tissue by inhibiting inflammatory cell accumulation in PMA-induced inflammation. In OXA-induced early delayed-type hypersensitivity (DTH), the macrolides (2 mg/ear) and dexamethasone (25 μg/ear) reduced ear tissue inflammatory cell infiltration and secretion of IL-4 while clarithromycin also decreased IFN-γ concentration. Macrolides showed better activity when administered after the challenge. In OXA-induced chronic DTH, azithromycin (1 mg/ear) reduced the number of ear tissue mast cells and decreased the concentration of IL-4 in ear tissue and of immunoglobulin (Ig)E in serum. Clarithromycin (1 mg/ear) reduced serum IgE concentration, possibly by a mechanism independent of IL-4, while both macrolides attenuated mast cell degranulation. In conclusion, azithromycin and clarithromycin attenuate pro-inflammatory cytokine production and leukocyte infiltration during innate immune reactions, while selectively affecting Th2 rather than Th1 immunity in DTH reactions.

  19. Comparison of Th1- and Th2-associated immune reactivities stimulated by single versus multiple vaccination of mice with irradiated Schistosoma mansoni cercariae

    SciTech Connect

    Caulada-Benedetti, Z.; Al-Zamel, F.; Sher, A.; James, S. )

    1991-03-01

    Mice immunized against Schistosoma mansoni by a single percutaneous exposure to radiation-attenuated parasite larvae demonstrate partial resistance to challenge infection that has been shown to correlate with development of cell-mediated immunity, whereas mice hyperimmunized by multiple exposure to attenuated larvae produce antibodies capable of transferring partial protection to naive recipients. Measurement of Ag-specific lymphokine responses in these animals suggested that the difference in resistance mechanisms may be due to the differential induction of Th subset response by the two immunization protocols. Thus, upon Ag stimulation, singly immunized mice predominantly demonstrated responses associated with Th1 reactivity, including IL-2 and IFN-gamma production, whereas multiply immunized animals showed increased IL-5, IL-4, and IgG1 antibody production associated with enhanced Th2 response. These responses demonstrated some degree of organ compartmentalization, with splenocytes demonstrating higher Th1-related lymphokine production and cells from draining lymph nodes showing stronger proliferation and Th2 type reactivity. However, hyperimmunized mice also continued to demonstrate substantial Th1-associated immune reactivity. Moreover, in vivo Ag challenge elicited activated larvacidal macrophages in hyperimmunized animals. These observations indicate that protective cell-mediated mechanisms associated with induction of CD4+ Th1 cell reactivity predominate in singly vaccinated mice. Further vaccination stimulates Th2 responses, such as enhanced IgG1 production, that may also contribute to protective immunity.

  20. Computational modeling of a direct propane fuel cell

    NASA Astrophysics Data System (ADS)

    Khakdaman, H.; Bourgault, Y.; Ternan, M.

    2011-03-01

    The first two dimensional mathematical model of a complete direct propane fuel cell (DPFC) is described. The governing equations were solved using FreeFem software that uses finite element methods. Robin boundary conditions were used to couple the anode, membrane, and cathode sub-domains successfully. The model showed that a polytetrafluoroethylene membrane having its pores filled with zirconium phosphate (ZrP-PTFE), in a DPFC at 150 °C performed much the same as other electrolytes; Nafion, aqueous H3PO4, and H2SO4 doped polybenzimidazole, when they were used in DPFCs. One advantage of a ZrP-PTFE at 150 °C is that it operates without liquid phase water. As a result corrosion will be much less severe and it may be possible for non-precious metal catalysts to be used. Computational results showed that the thickness of the catalyst layer could be increased sufficiently so that the pressure drop between the reactant and product channels of the interdigitated flow fields is small. By increasing the width of the land and therefore the reactant's contact time with the catalyst it was possible to approach 100% propane conversion. Therefore fuel cell operation with a minimum concentration of propane in the product stream should be possible. Finally computations of the electrical potential in the ZrP phase, the electron flux in the Pt/C phase, and the overpotential in both the anode and cathode catalyst layers showed that serious errors in the model occurred because proton diffusion, caused by the proton concentration gradient, was neglected in the equation for the conservation of protons.

  1. Hippocampal place cell instability after lesions of the head direction cell network

    NASA Technical Reports Server (NTRS)

    Calton, Jeffrey L.; Stackman, Robert W.; Goodridge, Jeremy P.; Archey, William B.; Dudchenko, Paul A.; Taube, Jeffrey S.; Oman, C. M. (Principal Investigator)

    2003-01-01

    The occurrence of cells that encode spatial location (place cells) or head direction (HD cells) in the rat limbic system suggests that these cell types are important for spatial navigation. We sought to determine whether place fields of hippocampal CA1 place cells would be altered in animals receiving lesions of brain areas containing HD cells. Rats received bilateral lesions of anterodorsal thalamic nuclei (ADN), postsubiculum (PoS), or sham lesions, before place cell recording. Although place cells from lesioned animals did not differ from controls on many place-field characteristics, such as place-field size and infield firing rate, the signal was significantly degraded with respect to measures of outfield firing rate, spatial coherence, and information content. Surprisingly, place cells from lesioned animals were more likely modulated by the directional heading of the animal. Rotation of the landmark cue showed that place fields from PoS-lesioned animals were not controlled by the cue and shifted unpredictably between sessions. Although fields from ADN-lesioned animals tended to have less landmark control than fields from control animals, this impairment was mild compared with cells recorded from PoS-lesioned animals. Removal of the prominent visual cue also led to instability of place-field representations in PoS-lesioned, but not ADN-lesioned, animals. Together, these findings suggest that an intact HD system is not necessary for the maintenance of place fields, but lesions of brain areas that convey the HD signal can degrade this signal, and lesions of the PoS might lead to perceptual or mnemonic deficits, leading to place-field instability between sessions.

  2. Suppression of Th1 and Th2 immune responses in mice by Sinomenine, an alkaloid extracted from the chinese medicinal plant Sinomenium acutum.

    PubMed

    Feng, Huang; Yamaki, Kouya; Takano, Hirohisa; Inoue, Ken-ichiro; Yanagisawa, Rie; Yoshino, Shin

    2006-12-01

    The present study was designed to investigate the effect of sinomenine (SIN), an alkaloid extracted from Sinomenium acutum, on Th1 and Th2 immune responses in mice. For this investigation, mice were S. C. immunized with ovalbumin (OVA) emulsified with complete Freund's adjuvant (day 0). Varying doses of SIN were orally administered daily over a period of 21 days, commencing on day 0. On day 21, anti-OVA IgG and proliferative responses of spleen cells to the antigen were measured. Anti-OVA IgG2a and IFN-gamma were measured as indicators of Th1 immune responses and anti-OVA IgG1, IgE, and IL-5 as those of Th2 responses. TGF-beta was measured as an indicator of Th3 immune responses. The results showed that treatment with SIN was followed by decreases in anti-OVA IgG and the antigen-specific splenocyte proliferation. Production of all isotypes of antibodies including anti-OVA IgG2a, IgG1 and IgE as well as secretion of cytokines such as IFN-gamma and IL-5 was suppressed by SIN, although the suppression of anti-OVA IgG2a and IFN-gamma by the alkaloid appeared to be greater than that of anti-OVA IgG1, IgE, and IL-5. In addition, SIN enhanced the secretion of TGF-beta. These results suggest that SIN appears to have suppressive effects on both Th1 and Th2 immune responses. The results also suggest that Th1 responses may be more preferentially suppressed by the Sinomenium acutum-derived alkaloid compared to Th2 responses. TGF-beta may at least in part contribute to the suppression of Th1 as well as Th2 immune responses.

  3. Directed Induction of Functional Motor Neuron-Like Cells from Genetically Engineered Human Mesenchymal Stem Cells

    PubMed Central

    Park, Hwan-Woo; Cho, Jung-Sun; Park, Chul-Kyu; Jung, Sung Jun; Park, Chang-Hwan; Lee, Shin-Jae; Oh, Seog Bae; Park, Young-Seok; Chang, Mi-Sook

    2012-01-01

    Cell replacement using stem cells is a promising therapeutic approach to treat degenerative motor neuron (MN) disorders, such as amyotrophic lateral sclerosis and spinal cord injury. Human bone marrow-derived mesenchymal stem cells (hMSCs) are a desirable cell source for autologous cell replacement therapy to treat nervous system injury due to their plasticity, low immunogenicity, and a lower risk of tumor formation than embryonic stem cells. However, hMSCs are inefficient with regards to differentiating into MN-like cells. To solve this limitation, we genetically engineered hMSCs to express MN-associated transcription factors, Olig2 and Hb9, and then treat the hMSCs expressing Olig2 and Hb9 with optimal MN induction medium (MNIM). This method of induction led to higher expression (>30% of total cells) of MN markers. Electrophysiological data revealed that the induced hMSCs had the excitable properties of neurons and were able to form functional connections with muscle fibers in vitro. Furthermore, when the induced hMSCs were transplanted into an injured organotypic rat spinal cord slice culture, an ex vivo model of spinal cord injury, they exhibited characteristics of MNs. The data strongly suggest that induced Olig2/Hb9-expressing hMSCs were clearly reprogrammed and directed toward a MN-like lineage. We propose that methods to induce Olig2 and Hb9, followed by further induction with MNIM have therapeutic potential for autologous cell replacement therapy to treat degenerative MN disorders. PMID:22496912

  4. SerpinB2 is critical to Th2 immunity against enteric nematode infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SerpinB2, a member of the serine protease inhibitor family, is expressed by macrophages and up-regulated significantly by inflammation. Recent studies implicated a role for SerpinB2 in the control of Th1 and Th2 immune responses, but the mechanisms of these effects are unknown. In the current study...

  5. A direct and non-redundant role for thymic stromal lymphopoietin on anti-viral CD8 T cell responses in the respiratory mucosa

    PubMed Central

    Shane, Hillary L.; Klonowski, Kimberly D.

    2014-01-01

    Mucosally produced thymic stromal lymphopoietin (TSLP) regulates Th2 responses by signaling to DCs and CD4 T cells. Activated CD8 T cells express the TSLP receptor (TSLP-R), yet a direct role for TSLP in CD8 T cell immunity in the mucosa has not been described. Since TSLP shares signaling components with IL-7, a cytokine important for the development and survival of memory CD8 T cells in systemic infection models, we hypothesized that TSLP spatially and non-redundantly supports the development of these cells in the respiratory tract. Here, we demonstrate that influenza infection induces the early expression of TSLP by lung epithelial cells with multiple consequences. The global loss of TSLP responsiveness in TSLP-R−/− mice enhanced morbidity and delayed viral clearance. Using a competitive adoptive transfer system, we demonstrate that selective loss of TSLP-R signaling on anti-viral CD8 T cells decreases their accumulation specifically in the respiratory tract as early as day 8 post infection, primarily due to a proliferation deficiency. Importantly, the subsequent persis