WorldWideScience

Sample records for immune cell recruitment

  1. Recruitment of activation receptors at inhibitory NK cell immune synapses.

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    Nicolas Schleinitz

    Full Text Available Natural killer (NK cell activation receptors accumulate by an actin-dependent process at cytotoxic immune synapses where they provide synergistic signals that trigger NK cell effector functions. In contrast, NK cell inhibitory receptors, including members of the MHC class I-specific killer cell Ig-like receptor (KIR family, accumulate at inhibitory immune synapses, block actin dynamics, and prevent actin-dependent phosphorylation of activation receptors. Therefore, one would predict inhibition of actin-dependent accumulation of activation receptors when inhibitory receptors are engaged. By confocal imaging of primary human NK cells in contact with target cells expressing physiological ligands of NK cell receptors, we show here that this prediction is incorrect. Target cells included a human cell line and transfected Drosophila insect cells that expressed ligands of NK cell activation receptors in combination with an MHC class I ligand of inhibitory KIR. The two NK cell activation receptors CD2 and 2B4 accumulated and co-localized with KIR at inhibitory immune synapses. In fact, KIR promoted CD2 and 2B4 clustering, as CD2 and 2B4 accumulated more efficiently at inhibitory synapses. In contrast, accumulation of KIR and of activation receptors at inhibitory synapses correlated with reduced density of the integrin LFA-1. These results imply that inhibitory KIR does not prevent CD2 and 2B4 signaling by blocking their accumulation at NK cell immune synapses, but by blocking their ability to signal within inhibitory synapses.

  2. Desirable cytolytic immune effector cell recruitment by interleukin-15 dendritic cells.

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    Van Acker, Heleen H; Beretta, Ottavio; Anguille, Sébastien; Caluwé, Lien De; Papagna, Angela; Van den Bergh, Johan M; Willemen, Yannick; Goossens, Herman; Berneman, Zwi N; Van Tendeloo, Viggo F; Smits, Evelien L; Foti, Maria; Lion, Eva

    2017-01-13

    Success of dendritic cell (DC) therapy in treating malignancies is depending on the DC capacity to attract immune effector cells, considering their reciprocal crosstalk is partially regulated by cell-contact-dependent mechanisms. Although critical for therapeutic efficacy, immune cell recruitment is a largely overlooked aspect regarding optimization of DC vaccination. In this paper we have made a head-to-head comparison of interleukin (IL)-15-cultured DCs and conventional IL-4-cultured DCs with regard to their proficiency in the recruitment of (innate) immune effector cells. Here, we demonstrate that IL-4 DCs are suboptimal in attracting effector lymphocytes, while IL15 DCs provide a favorable chemokine milieu for recruiting CD8+ T cells, natural killer (NK) cells and gamma delta (γδ) T cells. Gene expression analysis revealed that IL-15 DCs exhibit a high expression of chemokines involved in antitumor immune effector cell attraction, while IL-4 DCs display a more immunoregulatory profile characterized by the expression of Th2 and regulatory T cell-attracting chemokines. This is confirmed by functional data indicating an enhanced recruitment of granzyme B+ effector lymphocytes by IL-15 DCs, as compared to IL-4 DCs, and subsequent superior killing of tumor cells by the migrated lymphocytes. Elevated CCL4 gene expression in IL-15 DCs and lowered CCR5 expression on both migrated γδ T cells and NK cells, led to validation of increased CCL4 secretion by IL15 DCs. Moreover, neutralization of CCR5 prior to migration resulted in an important inhibition of γδ T cell and NK cell recruitment by IL-15 DCs. These findings further underscore the strong immunotherapeutic potential of IL-15 DCs.

  3. Dynamic immune cell recruitment after murine pulmonary Aspergillus fumigatus infection under different immunosuppressive regimens

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    Natarajaswamy Kalleda

    2016-07-01

    Full Text Available Humans are continuously exposed to airborne spores of the saprophytic fungus Aspergillus fumigatus. However, in healthy individuals pulmonary host defense mechanisms efficiently eliminate the fungus. In contrast, A. fumigatus causes devastating infections in immunocompromised patients. Host immune responses against A. fumigatus lung infections in immunocompromised conditions have remained largely elusive. Given the dynamic changes in immune cell subsets within tissues upon immunosuppressive therapy, we dissected the spatiotemporal pulmonary immune response after A. fumigatus infection to reveal basic immunological events that fail to effectively control invasive fungal disease. In different immunocompromised murine models, myeloid, notably neutrophils and macrophages, but not lymphoid cells were strongly recruited to the lungs upon infection. Other myeloid cells, particularly dendritic cells and monocytes, were only recruited to lungs of corticosteroid treated mice, which developed a strong pulmonary inflammation after infection. Lymphoid cells, particularly CD4+ or CD8+ T-cells and NK cells were highly reduced upon immunosuppression and not recruited after A. fumigatus infection. Moreover, adoptive CD11b+ myeloid cell transfer rescued cyclophosphamide immunosuppressed mice from lethal A. fumigatus infection but not cortisone and cyclophosphamide immunosuppressed mice. Our findings illustrate that CD11b+ myeloid cells are critical for anti-A. fumigatus defense under cyclophosphamide immunosuppressed conditions.

  4. AIRE expressing marginal zone dendritic cells balances adaptive immunity and T-follicular helper cell recruitment.

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    Lindmark, Evelina; Chen, Yunying; Georgoudaki, Anna-Maria; Dudziak, Diana; Lindh, Emma; Adams, William C; Loré, Karin; Winqvist, Ola; Chambers, Benedict J; Karlsson, Mikael C I

    2013-05-01

    Autoimmune polyendocrine syndrome Type I (APS I) results in multiple endocrine organ destruction and is caused by mutations in the Autoimmune regulator gene (AIRE). In the thymic stroma, cells expressing the AIRE gene dictate T cell education and central tolerance. Although this function is the most studied, AIRE is also expressed in the periphery in DCs and stromal cells. Still, how AIRE regulated transcription modifies cell behaviour in the periphery is largely unknown. Here we show that AIRE is specifically expressed by 33D1(+) DCs and dictates the fate of antibody secreting cell movement within the spleen. We also found that AIRE expressing 33D1(+) DCs expresses self-antigens as exemplified by the hallmark gene insulin. Also, as evidence for a regulatory function, absence of Aire in 33D1(+) DCs led to reduced levels of the chemokine CXCL12 and increased co-stimulatory properties. This resulted in altered activation and recruitment of T-follicular helper cells and germinal centre B cells. The altered balance leads to a change of the early response to a T cell-dependent antigen in Aire(-/-) mice. These findings add to the understanding of how specific DC subtypes regulate the early responses during T cell-dependent antibody responses within the spleen and further define the role of AIRE in the periphery as regulator of self-antigen expression and lymphocyte migration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Neutrophil Recruitment by Tumor Necrosis Factor from Mast Cells in Immune Complex Peritonitis

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    Zhang, Yan; Ramos, Bernard F.; Jakschik, Barbara A.

    1992-12-01

    During generalized immune complex-induced inflammation of the peritoneal cavity, two peaks of tumor necrosis factor (TNF) were observed in the peritoneal exudate of normal mice. In mast cell-deficient mice, the first peak was undetected, and the second peak of TNF and neutrophil influx were significantly reduced. Antibody to TNF significantly inhibited neutrophil infiltration in normal but not in mast cell-deficient mice. Mast cell repletion of the latter normalized TNF, neutrophil mobilization, and the effect of the antibody to TNF. Thus, in vivo, mast cells produce the TNF that augments neutrophil emigration.

  6. Macrophage interactions with polylactic acid and chitosan scaffolds lead to improved recruitment of human mesenchymal stem/stromal cells: a comprehensive study with different immune cells.

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    Caires, Hugo R; Esteves, Tiago; Quelhas, Pedro; Barbosa, Mário A; Navarro, Melba; Almeida, Catarina R

    2016-09-01

    Despite the importance of immune cell-biomaterial interactions for the regenerative outcome, few studies have investigated how distinct three-dimensional biomaterials modulate the immune cell-mediated mesenchymal stem/stromal cells (MSC) recruitment and function. Thus, this work compares the response of varied primary human immune cell populations triggered by different model scaffolds and describes its functional consequence on recruitment and motility of bone marrow MSC. It was found that polylactic acid (PLA) and chitosan scaffolds lead to an increase in the metabolic activity of macrophages but not of peripheral blood mononuclear cells (PBMC), natural killer (NK) cells or monocytes. PBMC and NK cells increase their cell number in PLA scaffolds and express a secretion profile that does not promote MSC recruitment. Importantly, chitosan increases IL-8, MIP-1, MCP-1 and RANTES secretion by macrophages while PLA stimulates IL-6, IL-8 and MCP-1 production, all chemokines that can lead to MSC recruitment. This secretion profile of macrophages in contact with biomaterials correlates with the highest MSC invasion. Furthermore, macrophages enhance stem cell motility within chitosan scaffolds by 44% but not in PLA scaffolds. Thus, macrophages are the cells that in contact with engineered biomaterials become activated to secrete bioactive molecules that stimulate MSC recruitment.

  7. Fibrocyte-like cells recruited to the spleen support innate and adaptive immune responses to acute injury or infection.

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    Kisseleva, Tatiana; von Köckritz-Blickwede, Maren; Reichart, Donna; McGillvray, Shauna M; Wingender, Gerhard; Kronenberg, Mitchell; Glass, Christopher K; Nizet, Victor; Brenner, David A

    2011-10-01

    Bone marrow (BM)-derived fibrocytes are a population of CD45(+) and collagen Type I-expressing cells that migrate to the spleen and to target injured organs, such as skin, lungs, kidneys, and liver. While CD45(+)Col(+) fibrocytes contribute to collagen deposition at the site of injury, the role of CD45(+)Col(+) cells in spleen has not been elucidated. Here, we demonstrate that hepatotoxic injury (CCl(4)), TGF-β1, lipopolysaccharide, or infection with Listeria monocytogenes induce rapid recruitment of CD45(+)Col(+) fibrocyte-like cells to the spleen. These cells have a gene expression pattern that includes antimicrobial factors (myleoperoxidase, cathelicidin, and defensins) and MHC II at higher levels than found on quiescent or activated macrophages. The immune functions of these splenic CD45(+)Col(+) fibrocyte-like cells include entrapment of bacteria into extracellular DNA-based structures containing cathelicidin and presentation of antigens to naïve CD8(+) T cells to induce their proliferation. Stimulation of these splenic fibrocyte-like cells with granulocyte macrophage-colony stimulating factor or macrophage-colony stimulating factor induces downregulation of collagen expression and terminal differentiation into the dendritic cells or macrophage. Thus, splenic CD45(+)Col(+) cells are a population of rapidly mobilized BM-derived fibrocyte-like cells that respond to inflammation or infection to participate in innate and adaptive immune responses.

  8. Alpha-Synuclein to the Rescue: Immune Cell Recruitment by Alpha-Synuclein during Gastrointestinal Infection.

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    Labrie, Viviane; Brundin, Patrik

    2017-09-02

    Intraneuronal accumulation of misfolded alpha-synuclein in the central and peripheral nervous systems is strongly linked to Parkinson disease (PD) and other related synucleinopathies. In rare inherited forms of PD, point mutations or gene multiplications mediate the formation of alpha-synuclein protein aggregates. However, in most PD cases it is presumed that the combined effects of ageing and environmental factors drive the formation of alpha-synuclein aggregates. Despite advances regarding alpha-synuclein pathobiology, the normal functions of this protein and factors that regulate its expression are not well understood. We discuss a recent study reporting that viral infection induces alpha-synuclein expression in neurons of the gastrointestinal tract. Alpha-synuclein levels increased during norovirus infection in the duodenum of children. In an in vitro paradigm, monomeric and oligomeric alpha-synuclein acted as chemoattractants for neutrophils and monocytes, and promoted the maturation of dendritic cells. This suggests that alpha-synuclein facilitates immune responses to infection. We explore the possibility that intestinal infections, and associated inflammation, place individuals at increased risk of PD by increasing alpha-synuclein levels and promoting the formation of alpha-synuclein aggregates that propagate in a prion-like fashion via the vagal nerve to the brainstem. © 2017 S. Karger AG, Basel.

  9. TIMP3 regulates mammary epithelial apoptosis with immune cell recruitment through differential TNF dependence.

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    Carlo V Hojilla

    Full Text Available Post-lactation mammary involution is a homeostatic process requiring epithelial apoptosis and clearance. Given that the deficiency of the extracellular metalloproteinase inhibitor TIMP3 impacts epithelial apoptosis and heightens inflammatory response, we investigated whether TIMP3 regulates these distinct processes during the phases of mammary gland involution in the mouse. Here we show that TIMP3 deficiency leads to TNF dysregulation, earlier caspase activation and onset of mitochondrial apoptosis. This accelerated first phase of involution includes faster loss of initiating signals (STAT3 activation; TGFβ3 concurrent with immediate luminal deconstruction through E-cadherin fragmentation. Epithelial apoptosis is followed by accelerated adipogenesis and a greater macrophage and T-cell infiltration in Timp3(-/- involuting glands. Crossing in Tnf deficiency abrogates caspase 3 activation, but heightens macrophage and T-cell influx into Timp3(-/- glands. The data indicate that TIMP3 differentially impacts apoptosis and inflammatory cell influx, based on involvement of TNF, during the process of mammary involution. An understanding of the molecular factors and wound healing microenvironment of the postpartum mammary gland may have implications for understanding pregnancy-associated breast cancer risk.

  10. CXC chemokine ligand 10 controls viral infection in the central nervous system: evidence for a role in innate immune response through recruitment and activation of natural killer cells.

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    Trifilo, Matthew J; Montalto-Morrison, Cynthia; Stiles, Linda N; Hurst, Kelley R; Hardison, Jenny L; Manning, Jerry E; Masters, Paul S; Lane, Thomas E

    2004-01-01

    How chemokines shape the immune response to viral infection of the central nervous system (CNS) has largely been considered within the context of recruitment and activation of antigen-specific lymphocytes. However, chemokines are expressed early following viral infection, suggesting an important role in coordinating innate immune responses. Herein, we evaluated the contributions of CXC chemokine ligand 10 (CXCL10) in promoting innate defense mechanisms following coronavirus infection of the CNS. Intracerebral infection of RAG1(-/-) mice with a recombinant CXCL10-expressing murine coronavirus (mouse hepatitis virus) resulted in protection from disease and increased survival that correlated with a significant increase in recruitment and activation of natural killer (NK) cells within the CNS. Accumulation of NK cells resulted in a reduction in viral titers that was dependent on gamma interferon secretion. These results indicate that CXCL10 expression plays a pivotal role in defense following coronavirus infection of the CNS by enhancing innate immune responses.

  11. Mast cells play an important role in chlamydia pneumoniae lung infection by facilitating immune cell recruitment into the airway.

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    Chiba, Norika; Shimada, Kenichi; Chen, Shuang; Jones, Heather D; Alsabeh, Randa; Slepenkin, Anatoly V; Peterson, Ellena; Crother, Timothy R; Arditi, Moshe

    2015-04-15

    Mast cells are known as central players in allergy and anaphylaxis, and they play a pivotal role in host defense against certain pathogens. Chlamydia pneumoniae is an important human pathogen, but it is unclear what role mast cells play during C. pneumoniae infection. We infected C57BL/6 (wild-type [WT]) and mast cell-deficient mice (Kit(W-sh/W-sh) [Wsh]) with C. pneumoniae. Wsh mice showed improved survival compared with WT mice, with fewer cells in Wsh bronchoalveolar lavage fluid (BALF), despite similar levels of cytokines and chemokines. We also found a more rapid clearance of bacteria from the lungs of Wsh mice compared with WT mice. Cromolyn, a mast cell stabilizer, reduced BALF cells and bacterial burden similar to the levels seen in Wsh mice; conversely, Compound 48/80, a mast cell degranulator, increased the number of BALF cells and bacterial burden. Histology showed that WT lungs had diffuse inflammation, whereas Wsh mice had patchy accumulations of neutrophils and perivascular accumulations of lymphocytes. Infected Wsh mice had reduced amounts of matrix metalloprotease-9 in BALF and were resistant to epithelial integral membrane protein degradation, suggesting that barrier integrity remains intact in Wsh mice. Mast cell reconstitution in Wsh mice led to enhanced bacterial growth and normal epithelial integral membrane protein degradation, highlighting the specific role of mast cells in this model. These data suggest that mast cells play a detrimental role during C. pneumoniae infection by facilitating immune cell infiltration into the airspace and providing a more favorable replicative environment for C. pneumoniae.

  12. Downregulation of CX3CR1 ameliorates experimental colitis: evidence for CX3CL1-CX3CR1-mediated immune cell recruitment.

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    Becker, Felix; Holthoff, Christina; Anthoni, Christoph; Rijcken, Emile; Alexander, J Steven; Gavins, Felicity N E; Spiegel, H U; Senninger, Norbert; Vowinkel, Thorsten

    2017-03-01

    Inflammatory conditions like inflammatory bowel diseases (IBD) are characterized by increased immune cell infiltration. The chemokine ligand CX3CL1 and its receptor CX3CR1 have been shown to be involved in leukocyte adhesion, transendothelial recruitment, and chemotaxis. Therefore, the objective of this study was to describe CX3CL1-CX3CR1-mediated signaling in the induction of immune cell recruitment during experimental murine colitis. Acute colitis was induced by dextran sodium sulfate (DSS), and sepsis was induced by injection of lipopolysaccharide (LPS). Serum concentrations of CX3CR1 and CX3CL1 were measured by ELISA. Wild-type and CX3CR1(-/-) mice were challenged with DSS, and on day 6, intravital microscopy was performed to monitor colonic leukocyte and platelet recruitment. Intestinal inflammation was assessed by disease activity, histopathology, and neutrophil infiltration. CX3CR1 was upregulated in DSS colitis and LPS-induced sepsis. CX3CR1(-/-) mice were protected from disease severity and intestinal injury in DSS colitis, and CX3CR1 deficiency resulted in reduced rolling of leukocytes and platelets. In the present study, we provide evidence for a crucial role of CX3CL1-CX3CR1 in experimental colitis, in particular for intestinal leukocyte recruitment during murine colitis. Our findings suggest that CX3CR1 blockade represents a potential therapeutic strategy for treatment of IBD.

  13. IL-17A promotes immune cell recruitment in human esophageal cancers and the infiltrating dendritic cells represent a positive prognostic marker for patient survival.

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    Lu, Lin; Pan, Ke; Zheng, Hai-Xia; Li, Jian-Jun; Qiu, Hui-Juan; Zhao, Jing-Jing; Weng, De-Sheng; Pan, Qiu-Zhong; Wang, Dan-Dan; Jiang, Shan-Shan; Chang, Alfred E; Li, Qiao; Xia, Jian-Chuan

    2013-10-01

    We previously reported that tumor-infiltrating interleukin (IL)-17A-producing cells play a protective role in human esophageal squamous cell carcinoma (ESCC). However, the potential mechanisms involved remain unclear. In the present study, we investigated the effects of IL-17A on immune cell recruitment and function in ESCC. In vitro chemotaxis assays using the ESCC cell lines EC109 and KYSE30 demonstrated that although IL-17A showed no significant direct effects on the migration of T cells, natural killer (NK) cells as well as dendritic cells (DCs), it could induce ESCC tumor cells to produce inflammatory chemokines, for example, CXCL9, CXCL10 and CCL2, CCL20, which are associated with the migration of T cells, NK cells, and DCs, respectively. In addition, IL-17A enhanced the cytotoxic effects of NK cells against tumor cells by augmenting the expression of cytotoxic molecules, for example, tumor necrosis factor-α, interferon-γ, Perforin, and Granzyme B and activation receptors, for example, NKp46, NKp44, NTB-A, and NKG2D on NK cells. Furthermore, immunohistochemical analysis revealed that the density of IL-17A-producing cells was positively and significantly associated with the density of CD1a DCs in tumor tissues. With the analyses of 181 ESCC patients, we found a correlation of higher number of tumor-infiltrating CD1a DCs with significantly improved overall survival of patients with ESCC. This study provides further understanding of the roles of Th17 cells in ESCC, which may contribute to the development of novel cancer immunotherapy strategies.

  14. Local applications of GM-CSF induce the recruitment of immune cells in cervical low-grade squamous intraepithelial lesions.

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    Hubert, Pascale; Doyen, Jean; Capelle, Xavier; Arafa, Mohammad; Renoux, Virginie; Bisig, Bettina; Seidel, Laurence; Evrard, Brigitte; Bousarghin, Latifa; Gerday, Colette; Boniver, Jacques; Foidart, Jean-Michel; Delvenne, Philippe; Jacobs, Nathalie

    2010-08-01

    Quantitative alterations of antigen-presenting cells (APC) in (pre)neoplastic lesions of the uterine cervix associated with human papillomavirus (HPV) infection suggest a diminished capacity to capture viral antigens and to induce a protective immune response. To test whether a cervical application of GM-CSF could restore an immune response against HPV in women with cervical low-grade squamous intraepithelial lesions (LSIL), we performed two clinical trials with 11 healthy women and 15 patients with LSIL. GM-CSF applications were well tolerated in all enrolled women, and no difference in toxicity between the treated and placebo groups was observed during the follow-up (until 30 months). Interestingly, in the GM-CSF treated group, a significant increase of APC and cytotoxic T-lymphocyte infiltration was observed in the cervical biopsies with no change in regulatory T cell numbers. All the HPV16(+) patients exhibited an immune response against HPV16 after GM-CSF applications, as shown by NK and/or T cells producing IFN-gamma whereas no cellular immune response was observed before the treatment. Moreover, the anti-virus-like particles antibody titers also increased after the treatment. These encouraging results obtained from a limited number of subjects justify further study on the therapeutic effect of APC in cervical (pre)neoplastic lesions.

  15. HPV16-E7 expression in squamous epithelium creates a local immune suppressive environment via CCL2- and CCL5- mediated recruitment of mast cells.

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    Bergot, Anne-Sophie; Ford, Neill; Leggatt, Graham R; Wells, James W; Frazer, Ian H; Grimbaldeston, Michele A

    2014-10-01

    Human Papillomavirus (HPV) 16 E7 protein promotes the transformation of HPV infected epithelium to malignancy. Here, we use a murine model in which the E7 protein of HPV16 is expressed as a transgene in epithelium to show that mast cells are recruited to the basal layer of E7-expressing epithelium, and that this recruitment is dependent on the epithelial hyperproliferation induced by E7 by inactivating Rb dependent cell cycle regulation. E7 induced epithelial hyperplasia is associated with increased epidermal secretion of CCL2 and CCL5 chemokines, which attract mast cells to the skin. Mast cells in E7 transgenic skin, in contrast to those in non-transgenic skin, exhibit degranulation. Notably, we found that resident mast cells in E7 transgenic skin cause local immune suppression as evidenced by tolerance of E7 transgenic skin grafts when mast cells are present compared to the rejection of mast cell-deficient E7 grafts in otherwise competent hosts. Thus, our findings suggest that mast cells, recruited towards CCL2 and CCL5 expressed by epithelium induced to proliferate by E7, may contribute to an immunosuppressive environment that enables the persistence of HPV E7 protein induced pre-cancerous lesions.

  16. HPV16-E7 expression in squamous epithelium creates a local immune suppressive environment via CCL2- and CCL5- mediated recruitment of mast cells.

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    Anne-Sophie Bergot

    2014-10-01

    Full Text Available Human Papillomavirus (HPV 16 E7 protein promotes the transformation of HPV infected epithelium to malignancy. Here, we use a murine model in which the E7 protein of HPV16 is expressed as a transgene in epithelium to show that mast cells are recruited to the basal layer of E7-expressing epithelium, and that this recruitment is dependent on the epithelial hyperproliferation induced by E7 by inactivating Rb dependent cell cycle regulation. E7 induced epithelial hyperplasia is associated with increased epidermal secretion of CCL2 and CCL5 chemokines, which attract mast cells to the skin. Mast cells in E7 transgenic skin, in contrast to those in non-transgenic skin, exhibit degranulation. Notably, we found that resident mast cells in E7 transgenic skin cause local immune suppression as evidenced by tolerance of E7 transgenic skin grafts when mast cells are present compared to the rejection of mast cell-deficient E7 grafts in otherwise competent hosts. Thus, our findings suggest that mast cells, recruited towards CCL2 and CCL5 expressed by epithelium induced to proliferate by E7, may contribute to an immunosuppressive environment that enables the persistence of HPV E7 protein induced pre-cancerous lesions.

  17. Hepatitis C Virus Sensing by Human Trophoblasts Induces Innate Immune Responses and Recruitment of Maternal NK Cells: Potential Implications for Limiting Vertical Transmission.

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    Giugliano, Silvia; Petroff, Margaret G; Warren, Bryce D; Jasti, Susmita; Linscheid, Caitlin; Ward, Ashley; Kramer, Anita; Dobrinskikh, Evgenia; Sheiko, Melissa A; Gale, Michael; Golden-Mason, Lucy; Winn, Virginia D; Rosen, Hugo R

    2015-10-15

    Hepatitis C virus (HCV) is the world's most common blood-borne viral infection for which there is no vaccine. The rates of vertical transmission range between 3 and 6% with odds 90% higher in the presence of HIV coinfection. Prevention of vertical transmission is not possible because of lack of an approved therapy for use in pregnancy or an effective vaccine. Recently, HCV has been identified as an independent risk factor for preterm delivery, perinatal mortality, and other complications. In this study, we characterized the immune responses that contribute to the control of viral infection at the maternal-fetal interface (MFI) in the early gestational stages. In this study, we show that primary human trophoblast cells and an extravillous trophoblast cell line (HTR8), from first and second trimester of pregnancy, express receptors relevant for HCV binding/entry and are permissive for HCV uptake. We found that HCV-RNA sensing by human trophoblast cells induces robust upregulation of type I/III IFNs and secretion of multiple chemokines that elicit recruitment and activation of decidual NK cells. Furthermore, we observed that HCV-RNA transfection induces a proapoptotic response within HTR8 that could affect the morphology of the placenta. To our knowledge, for the first time, we demonstrate that HCV-RNA sensing by human trophoblast cells elicits a strong antiviral response that alters the recruitment and activation of innate immune cells at the MFI. This work provides a paradigm shift in our understanding of HCV-specific immunity at the MFI as well as novel insights into mechanisms that limit vertical transmission but may paradoxically lead to virus-related pregnancy complications.

  18. CXC Chemokine Ligand 10 Controls Viral Infection in the Central Nervous System: Evidence for a Role in Innate Immune Response through Recruitment and Activation of Natural Killer Cells

    OpenAIRE

    Trifilo, Matthew J.; Montalto-Morrison, Cynthia; Stiles, Linda N.; Hurst, Kelley R.; Hardison, Jenny L.; Manning, Jerry E.; Masters, Paul S.; Lane, Thomas E.

    2004-01-01

    How chemokines shape the immune response to viral infection of the central nervous system (CNS) has largely been considered within the context of recruitment and activation of antigen-specific lymphocytes. However, chemokines are expressed early following viral infection, suggesting an important role in coordinating innate immune responses. Herein, we evaluated the contributions of CXC chemokine ligand 10 (CXCL10) in promoting innate defense mechanisms following coronavirus infection of the C...

  19. β7 Integrin controls mast cell recruitment, whereas αE integrin modulates the number and function of CD8+ T cells in immune complex-mediated tissue injury.

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    Yamada, Daisuke; Kadono, Takafumi; Masui, Yuri; Yanaba, Koichi; Sato, Shinichi

    2014-05-01

    Immune complex (IC) deposition causes significant tissue injury associated with various autoimmune diseases such as vasculitis. In the cascade of inflammation, cell-to-cell and cell-to-matrix adhesion via adhesion molecules are essential. To assess the role of αE and β7 integrin in IC-mediated tissue injury, peritoneal and cutaneous reverse-passive Arthus reaction was examined in mice lacking αE integrin (αE(-/-)) or β7 integrin (β7(-/-)). Both αE(-/-) and β7(-/-) mice exhibited significantly attenuated neutrophil infiltration in the peritoneal and cutaneous Arthus reaction. β7 integrin deficiency, not αE integrin deficiency, significantly reduced the number of mast cells in the peritoneal cavity, which was consistent with the result that mast cells expressed only α4β7 integrin, not αEβ7 integrin. αE(-/-) mice instead revealed the reduction of CD8(+) T cells in the peritoneal cavity, and nearly half of them in wild-type mice expressed αE integrin. These αE(+)CD8(+) T cells produced more proinflammatory cytokines than αE(-)CD8(+) T cells, and adoptive transfer of αE(+)CD8(+) T cell into αE(-/-) recipients restored cutaneous and peritoneal Arthus reaction. These results suggest that in the peritoneal and cutaneous reverse-passive Arthus reaction, α4β7 integrin is involved in the migration of mast cells for initial IC recognition. αEβ7 integrin, in contrast, contributes by recruiting αE(+)CD8(+) T cells, which produce more proinflammatory cytokines than αE(-)CD8(+) T cells and amplify IC-mediated inflammation.

  20. Novel process of intrathymic tumor-immune tolerance through CCR2-mediated recruitment of Sirpα+ dendritic cells: a murine model.

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    Tomohisa Baba

    Full Text Available Immune surveillance system can detect more efficiently secretory tumor-specific antigens, which are superior as a target for cancer immunotherapy. On the contrary, immune tolerance can be induced in the thymus when a tumor antigen is massively secreted into circulation. Thus, the secretion of tumor-specific antigen may have contradictory roles in tumor immunity in a context-dependent manner. However, it remains elusive on the precise cellular mechanism of intrathymic immune tolerance against tumor antigens. We previously demonstrated that a minor thymic conventional dendritic cell (cDC subset, CD8α(-Sirpα(+ cDCs, but not the major subset, CD8α(+Sirpα(- cDCs can selectively capture blood-borne antigens and crucially contribute to the self-tolerance. In the present study, we further demonstrated that Sirpα(+ cDCs can capture a blood-borne antigen leaking inside the interlobular vascular-rich regions (IVRs. Blood-borne antigen selectively captured by Sirpα(+ cDCs can induce antigen-specific Treg generation or negative selection, depending on the immunogenicity of the presented antigen. Furthermore, CCR2 expression by thymic Sirpα(+ cDCs and abundant expression of its ligands, particularly, CCL2 by tumor-bearing mice prompted us to examine the function of thymic Sirpα(+ cDCs in tumor-bearing mice. Interestingly, tumor-bearing mice deposited CCL2 inside IVRs in the thymus. Moreover, tumor formation induced the accumulation of Sirpα(+ cDCs in IVRs under the control of CCR2-CCL2 axis and enhanced their capacity to take up antigens, resulting in the shift from Treg differentiation to negative selection. Finally, intrathymic negative selection similarly ensued in CCR2-competent mice once the tumor-specific antigen was secreted into bloodstream. Thus, we demonstrated that thymic Sirpα(+ cDCs crucially contribute to this novel process of intrathymic tumor immune tolerance.

  1. Analysing immune cell migration.

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    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  2. Arabidopsis poly(A) polymerase PAPS1 limits founder-cell recruitment to organ primordia and suppresses the salicylic acid-independent immune response downstream of EDS1/PAD4.

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    Trost, Gerda; Vi, Son Lang; Czesnick, Hjördis; Lange, Peggy; Holton, Nick; Giavalisco, Patrick; Zipfel, Cyril; Kappel, Christian; Lenhard, Michael

    2014-03-01

    Polyadenylation of pre-mRNAs by poly(A) polymerase (PAPS) is a critical process in eukaryotic gene expression. As found in vertebrates, plant genomes encode several isoforms of canonical nuclear PAPS enzymes. In Arabidopsis thaliana these isoforms are functionally specialized, with PAPS1 affecting both organ growth and immune response, at least in part by the preferential polyadenylation of subsets of pre-mRNAs. Here, we demonstrate that the opposite effects of PAPS1 on leaf and flower growth reflect the different identities of these organs, and identify a role for PAPS1 in the elusive connection between organ identity and growth patterns. The overgrowth of paps1 mutant petals is due to increased recruitment of founder cells into early organ primordia, and suggests that PAPS1 activity plays unique roles in influencing organ growth. By contrast, the leaf phenotype of paps1 mutants is dominated by a constitutive immune response that leads to increased resistance to the biotrophic oomycete Hyaloperonospora arabidopsidis and reflects activation of the salicylic acid-independent signalling pathway downstream of ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1)/PHYTOALEXIN DEFICIENT4 (PAD4). These findings provide an insight into the developmental and physiological basis of the functional specialization amongst plant PAPS isoforms.

  3. Intradermal delivery of Shigella IpaB and IpaD type III secretion proteins: kinetics of cell recruitment and antigen uptake, mucosal and systemic immunity, and protection across serotypes.

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    Heine, Shannon J; Diaz-McNair, Jovita; Andar, Abhay U; Drachenberg, Cinthia B; van de Verg, Lillian; Walker, Richard; Picking, Wendy L; Pasetti, Marcela F

    2014-02-15

    Shigella is one of the leading pathogens contributing to the vast pediatric diarrheal disease burden in low-income countries. No licensed vaccine is available, and the existing candidates are only partially effective and serotype specific. Shigella type III secretion system proteins IpaB and IpaD, which are conserved across Shigella spp., are candidates for a broadly protective, subunit-based vaccine. In this study, we investigated the immunogenicity and protective efficacy of IpaB and IpaD administered intradermally (i.d.) with a double-mutant of the Escherichia coli heat-labile enterotoxin (dmLT) adjuvant using microneedles. Different dosage levels of IpaB and IpaD, with or without dmLT, were tested in mice. Vaccine delivery into the dermis, recruitment of neutrophils, macrophages, dendritic cells, and Langerhans cells, and colocalization of vaccine Ag within skin-activated APC were demonstrated through histology and immunofluorescence microscopy. Ag-loaded neutrophils, macrophages, dendritic cells, and Langerhans cells remained in the tissue at least 1 wk. IpaB, IpaD, and dmLT-specific serum IgG- and IgG-secreting cells were produced following i.d. immunization. The protective efficacy was 70% against Shigella flexneri and 50% against Shigella sonnei. Similar results were obtained when the vaccine was administered intranasally, with the i.d. route requiring 25-40 times lower doses. Distinctively, IgG was detected in mucosal secretions; secretory IgA, as well as mucosal and systemic IgA Ab-secreting cells, were seemingly absent. Vaccine-induced T cells produced IFN-γ, IL-2, TNF-α, IL-17, IL-4, IL-5, and IL-10. These results demonstrate the potential of i.d. vaccination with IpaB and IpaD to prevent Shigella infection and support further studies in humans.

  4. HIV-1 evades innate immune recognition through specific cofactor recruitment

    Science.gov (United States)

    Rasaiyaah, Jane; Tan, Choon Ping; Fletcher, Adam J.; Price, Amanda J.; Blondeau, Caroline; Hilditch, Laura; Jacques, David A.; Selwood, David L.; James, Leo C.; Noursadeghi, Mahdad; Towers, Greg J.

    2013-11-01

    Human immunodeficiency virus (HIV)-1 is able to replicate in primary human macrophages without stimulating innate immunity despite reverse transcription of genomic RNA into double-stranded DNA, an activity that might be expected to trigger innate pattern recognition receptors. We reasoned that if correctly orchestrated HIV-1 uncoating and nuclear entry is important for evasion of innate sensors then manipulation of specific interactions between HIV-1 capsid and host factors that putatively regulate these processes should trigger pattern recognition receptors and stimulate type 1 interferon (IFN) secretion. Here we show that HIV-1 capsid mutants N74D and P90A, which are impaired for interaction with cofactors cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and cyclophilins (Nup358 and CypA), respectively, cannot replicate in primary human monocyte-derived macrophages because they trigger innate sensors leading to nuclear translocation of NF-κB and IRF3, the production of soluble type 1 IFN and induction of an antiviral state. Depletion of CPSF6 with short hairpin RNA expression allows wild-type virus to trigger innate sensors and IFN production. In each case, suppressed replication is rescued by IFN-receptor blockade, demonstrating a role for IFN in restriction. IFN production is dependent on viral reverse transcription but not integration, indicating that a viral reverse transcription product comprises the HIV-1 pathogen-associated molecular pattern. Finally, we show that we can pharmacologically induce wild-type HIV-1 infection to stimulate IFN secretion and an antiviral state using a non-immunosuppressive cyclosporine analogue. We conclude that HIV-1 has evolved to use CPSF6 and cyclophilins to cloak its replication, allowing evasion of innate immune sensors and induction of a cell-autonomous innate immune response in primary human macrophages.

  5. Innate immune cells in the pathogenesis of primary systemic vasculitis.

    Science.gov (United States)

    Misra, Durga Prasanna; Agarwal, Vikas

    2016-02-01

    Innate immune system forms the first line of defense against foreign substances. Neutrophils, eosinophils, erythrocytes, platelets, monocytes, macrophages, dendritic cells, γδ T cells, natural killer and natural killer T cells comprise the innate immune system. Genetic polymorphisms influencing the activation of innate immune cells predispose to development of vasculitis and influence its severity. Abnormally activated innate immune cells cross-talk with other cells of the innate immune system, present antigens more efficiently and activate T and B lymphocytes and cause tissue destruction via cell-mediated cytotoxicity and release of pro-inflammatory cytokines. These secreted cytokines further recruit other cells to the sites of vascular injury. They are involved in both the initiation as well as the perpetuation of vasculitis. Evidences suggest reversal of aberrant activation of immune cells in response to therapy. Understanding the role of innate immune cells in vasculitis helps understand the potential of therapeutic modulation of their activation to treat vasculitis.

  6. Pseudomonas aeruginosa airway infection recruits and modulates neutrophilic myeloid-derived suppressor cells

    Directory of Open Access Journals (Sweden)

    Hasan Halit Öz

    2016-11-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen that causes infections mainly in patients with cystic fibrosis (CF lung disease. Despite innate and adaptive immune responses upon infection, P. aeruginosa is capable of efficiently escaping host defenses, but the underlying immune mechanisms remain poorly understood. Myeloid-derived suppressor cells (MDSCs are innate immune cells that are functionally characterized by their potential to suppress T- and natural killer (NK-cell responses. Here we demonstrate, using an airway in vivo infection model, that P. aeruginosa recruits and activates neutrophilic MDSCs, which functionally suppress T-cell responses. We further show that the CF gene defect (cystic fibrosis transmembrane conductance regulator, CFTR modulates the functionality, but not the recruitment or generation of neutrophilic MDSCs. Collectively, we define a mechanism by which P. aeruginosa airway infection undermines host immunity by modulating neutrophilic MDSCs in vivo.

  7. DNA vaccination in fish promotes an early chemokine-related recruitment of B cells to the muscle

    DEFF Research Database (Denmark)

    Castro, R.; Martínez-Alonso, S.; Fischer, U.

    2013-01-01

    might explain the recruitment of immune cells to the site of DNA injection. Our results suggest that B cells are involved in the initial phase of the immune response to intramuscular DNA vaccination against VHSV. This appears to be a major difference to what we know from mammalian models where T cells...

  8. F-actin-binding protein drebrin regulates CXCR4 recruitment to the immune synapse.

    Science.gov (United States)

    Pérez-Martínez, Manuel; Gordón-Alonso, Mónica; Cabrero, José Román; Barrero-Villar, Marta; Rey, Mercedes; Mittelbrunn, María; Lamana, Amalia; Morlino, Giulia; Calabia, Carmen; Yamazaki, Hiroyuki; Shirao, Tomoaki; Vázquez, Jesús; González-Amaro, Roberto; Veiga, Esteban; Sánchez-Madrid, Francisco

    2010-04-01

    The adaptive immune response depends on the interaction of T cells and antigen-presenting cells at the immune synapse. Formation of the immune synapse and the subsequent T-cell activation are highly dependent on the actin cytoskeleton. In this work, we describe that T cells express drebrin, a neuronal actin-binding protein. Drebrin colocalizes with the chemokine receptor CXCR4 and F-actin at the peripheral supramolecular activation cluster in the immune synapse. Drebrin interacts with the cytoplasmic tail of CXCR4 and both proteins redistribute to the immune synapse with similar kinetics. Drebrin knockdown in T cells impairs the redistribution of CXCR4 and inhibits actin polymerization at the immune synapse as well as IL-2 production. Our data indicate that drebrin exerts an unexpected and relevant functional role in T cells during the generation of the immune response.

  9. Tracking immune cells in vivo using magnetic resonance imaging.

    Science.gov (United States)

    Ahrens, Eric T; Bulte, Jeff W M

    2013-10-01

    The increasing complexity of in vivo imaging technologies, coupled with the development of cell therapies, has fuelled a revolution in immune cell tracking in vivo. Powerful magnetic resonance imaging (MRI) methods are now being developed that use iron oxide- and ¹⁹F-based probes. These MRI technologies can be used for image-guided immune cell delivery and for the visualization of immune cell homing and engraftment, inflammation, cell physiology and gene expression. MRI-based cell tracking is now also being applied to evaluate therapeutics that modulate endogenous immune cell recruitment and to monitor emerging cellular immunotherapies. These recent uses show that MRI has the potential to be developed in many applications to follow the fate of immune cells in vivo.

  10. NK cells and immune "memory"

    National Research Council Canada - National Science Library

    Sun, Joseph C; Lopez-Verges, Sandra; Kim, Charles C; DeRisi, Joseph L; Lanier, Lewis L

    2011-01-01

    Immunological memory is a hallmark of the adaptive immune system. However, the ability to remember and respond more robustly against a second encounter with the same pathogen has been described in organisms lacking T and B cells...

  11. NOD2 dependent neutrophil recruitment is required for early protective immune responses against infectious Litomosoides sigmodontis L3 larvae

    Science.gov (United States)

    Ajendra, Jesuthas; Specht, Sabine; Ziewer, Sebastian; Schiefer, Andrea; Pfarr, Kenneth; Parčina, Marijo; Kufer, Thomas A.; Hoerauf, Achim; Hübner, Marc P.

    2016-01-01

    Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) recognizes muramyl dipeptide (MDP) of bacterial cell walls, triggering NFκB-induced pro-inflammation. As most human pathogenic filariae contain Wolbachia endobacteria that synthesize the MDP-containing cell wall precursor lipid II, NOD2’s role during infection with the rodent filaria Litomosoides sigmodontis was investigated. In NFκB reporter-cells, worm-extract containing Wolbachia induced NOD2 and NOD1. NOD2-deficient mice infected with L. sigmodontis had significantly more worms than wildtype controls early in infection. Increased worm burden was not observed after subcutaneous infection, suggesting that protective NOD2-dependent immune responses occur within the skin. Flow cytometry demonstrated that neutrophil recruitment to the skin was impaired in NOD2−/− mice after intradermal injection of third stage larvae (L3), and blood neutrophil numbers were reduced after L. sigmodontis infection. PCR array supported the requirement of NOD2 for recruitment of neutrophils to the skin, as genes associated with neutrophil recruitment and activation were downregulated in NOD2−/− mice after intradermal L3 injection. Neutrophil depletion before L. sigmodontis infection increased worm recovery in wildtype mice, confirming that neutrophils are essential against invading L3 larvae. This study indicates that NOD-like receptors are implemented in first-line protective immune responses against filarial nematodes. PMID:28004792

  12. Soluble CCL5 derived from bone marrow-derived mesenchymal stem cells and activated by amyloid β ameliorates Alzheimer's disease in mice by recruiting bone marrow-induced microglia immune responses.

    Science.gov (United States)

    Lee, Jong Kil; Schuchman, Edward H; Jin, Hee Kyung; Bae, Jae-sung

    2012-07-01

    Microglia have the ability to eliminate amyloid β (Aβ) by a cell-specific phagocytic mechanism, and bone marrow (BM) stem cells have shown a beneficial effect through endogenous microglia activation in the brains of Alzheimer's disease (AD) mice. However, the mechanisms underlying BM-induced activation of microglia have not been resolved. Here we show that BM-derived mesenchymal stem cells (MSCs) induced the migration of microglia when exposed to Aβ in vitro. Cytokine array analysis of the BM-MSC media obtained after stimulation by Aβ further revealed elevated release of the chemoattractive factor, CCL5. We also observed that CCL5 was increased when BM-MSCs were transplanted into the brains of Aβ-deposited AD mice, but not normal mice. Interestingly, alternative activation of microglia in AD mice was associated with elevated CCL5 expression following intracerebral BM-MSC transplantation. Furthermore, by generating an AD-green fluorescent protein chimeric mouse, we ascertained that endogenous BM cells, recruited into the brain by CCL5, induced microglial activation. Additionally, we observed that neprilysin and interleukin-4 derived from the alternative microglia were associated with a reduction in Aβ deposition and memory impairment in AD mice. These results suggest that the beneficial effects observed in AD mice after intracerebral SC transplantation may be explained by alternative microglia activation. The recruitment of the alternative microglia into the brain is driven by CCL5 secretion from the transplanted BM-MSCs, which itself is induced by Aβ deposition in the AD brain. Copyright © 2012 AlphaMed Press.

  13. IKKα Promotes Intestinal Tumorigenesis by Limiting Recruitment of M1-like Polarized Myeloid Cells

    Directory of Open Access Journals (Sweden)

    Serkan I. Göktuna

    2014-06-01

    Full Text Available The recruitment of immune cells into solid tumors is an essential prerequisite of tumor development. Depending on the prevailing polarization profile of these infiltrating leucocytes, tumorigenesis is either promoted or blocked. Here, we identify IκB kinase α (IKKα as a central regulator of a tumoricidal microenvironment during intestinal carcinogenesis. Mice deficient in IKKα kinase activity are largely protected from intestinal tumor development that is dependent on the enhanced recruitment of interferon γ (IFNγ-expressing M1-like myeloid cells. In IKKα mutant mice, M1-like polarization is not controlled in a cell-autonomous manner but, rather, depends on the interplay of both IKKα mutant tumor epithelia and immune cells. Because therapies aiming at the tumor microenvironment rather than directly at the mutated cancer cell may circumvent resistance development, we suggest IKKα as a promising target for colorectal cancer (CRC therapy.

  14. Immunosuppressive cells in tumor immune escape and metastasis.

    Science.gov (United States)

    Liu, Yang; Cao, Xuetao

    2016-05-01

    Tumor immune escape and the initiation of metastasis are critical steps in malignant progression of tumors and have been implicated in the failure of some clinical cancer immunotherapy. Tumors develop numerous strategies to escape immune surveillance or metastasize: Tumors not only modulate the recruitment and expansion of immunosuppressive cell populations to develop the tumor microenvironment or pre-metastatic niche but also switch the phenotype and function of normal immune cells from a potentially tumor-reactive state to a tumor-promoting state. Immunosuppressive cells facilitate tumor immune escape by inhibiting antitumor immune responses and furthermore promote tumor metastasis by inducing immunosuppression, promoting tumor cell invasion and intravasation, establishing a pre-metastatic niche, facilitating epithelial-mesenchymal transition, and inducing angiogenesis at primary tumor or metastatic sites. Numerous translational studies indicate that it is possible to inhibit tumor immune escape and prevent tumor metastasis by blocking immunosuppressive cells and eliminating immunosuppressive mechanisms that are induced by either immunosuppressive cells or tumor cells. Furthermore, many clinical trials targeting immunosuppressive cells have also achieved good outcome. In this review, we focus on the underlying mechanisms of immunosuppressive cells in promoting tumor immune escape and metastasis, discuss our current understanding of the interactions between immunosuppressive cells and tumor cells in the tumor microenvironment, and suggest future research directions as well as potential clinical strategies in cancer immunotherapy.

  15. In situ tissue regeneration: chemoattractants for endogenous stem cell recruitment.

    Science.gov (United States)

    Vanden Berg-Foels, Wendy S

    2014-02-01

    Tissue engineering uses cells, signaling molecules, and/or biomaterials to regenerate injured or diseased tissues. Ex vivo expanded mesenchymal stem cells (MSC) have long been a cornerstone of regeneration therapies; however, drawbacks that include altered signaling responses and reduced homing capacity have prompted investigation of regeneration based on endogenous MSC recruitment. Recent successful proof-of-concept studies have further motivated endogenous MSC recruitment-based approaches. Stem cell migration is required for morphogenesis and organogenesis during development and for tissue maintenance and injury repair in adults. A biomimetic approach to in situ tissue regeneration by endogenous MSC requires the orchestration of three main stages: MSC recruitment, MSC differentiation, and neotissue maturation. The first stage must result in recruitment of a sufficient number of MSC, capable of effecting regeneration, to the injured or diseased tissue. One of the challenges for engineering endogenous MSC recruitment is the selection of effective chemoattractant(s). The objective of this review is to synthesize and evaluate evidence of recruitment efficacy by reported chemoattractants, including growth factors, chemokines, and other more recently appreciated MSC chemoattractants. The influence of MSC tissue sources, cell culture methods, and the in vitro and in vivo environments is discussed. This growing body of knowledge will serve as a basis for the rational design of regenerative therapies based on endogenous MSC recruitment. Successful endogenous MSC recruitment is the first step of successful tissue regeneration.

  16. Pasteurella multocida and immune cells.

    Science.gov (United States)

    Kubatzky, Katharina F

    2012-01-01

    Pasteurella multocida was first discovered by Perroncito in 1878 and named after Louis Pasteur who first isolated and described this Gram-negative bacterium as the cause of fowl disease in 1880. Subsequently, P. multocida was also found to cause atrophic rhinitis in pigs, haemorrhagic septicaemia in cattle and respiratory diseases in many other animals. Among other factors such as lipopolysaccharide, outer membrane proteins and its capsule, the protein toxin (PMT) of P. multocida is an important virulence factor that determines the immunological response of the host's immune system. However, the exact molecular mechanisms taking place in cells of the innate and adaptive immune system are largely unknown for any of these virulence factors. Due to the obvious function of PMT on cells of the porcine skeletal system where it causes bone destruction, PMT was regarded as an osteolytic protein toxin. However, it remained unclear what the actual benefit for the bacteria would be. Recently, more attention was drawn to the osteoimmunological effects of PMT and the interplay between bone and immune cells. This review summarises the knowledge of effects of P. multocida virulence factors on the host's immune system.

  17. Cell-mediated immune response

    DEFF Research Database (Denmark)

    Meyer, Sonja Izquierdo; Fuglsang, Katrine; Blaakaer, Jan

    2014-01-01

    OBJECTIVE: This clinical review aims to assess the efficacy of human papillomavirus 16/18 (HPV16/18) vaccination on the cell-mediated immune response in women with existing cervical intraepithelial neoplasia or cervical cancer induced by HPV16 or HPV18. DATA SOURCES AND STUDY SELECTION: A focused...... and thorough literature search conducted in five different databases found 996 publications. Six relevant articles were chosen for further review. In total, 154 patients (>18 years of age) were enrolled in prospective study trials with 3-15 months of follow up. The vaccine applications were administered two...... triggered a detectable cell-mediated immune response, some of which were statistically significant. Correlations between immunological response and clinical outcome (histopathology) were not significant, so neoplasms may not be susceptible to vaccine-generated cytotoxic T cells (CD8(+)). CONCLUSIONS...

  18. Are mesenchymal stromal cells immune cells?

    NARCIS (Netherlands)

    M.J. Hoogduijn (Martin)

    2015-01-01

    textabstractMesenchymal stromal cells (MSCs) are considered to be promising agents for the treatment of immunological disease. Although originally identified as precursor cells for mesenchymal lineages, in vitro studies have demonstrated that MSCs possess diverse immune regulatory capacities. Pre-cl

  19. Mast cells mediate neutrophil recruitment during atherosclerotic plaque progression

    NARCIS (Netherlands)

    Wezel, Anouk; Lagraauw, H Maxime; van der Velden, Daniël; de Jager, Saskia C A; Quax, Paul H A; Kuiper, Johan; Bot, Ilze

    2015-01-01

    AIMS: Activated mast cells have been identified in the intima and perivascular tissue of human atherosclerotic plaques. As mast cells have been described to release a number of chemokines that mediate leukocyte fluxes, we propose that activated mast cells may play a pivotal role in leukocyte recruit

  20. Immune Cells in Blood Recognize Tumors

    Science.gov (United States)

    NCI scientists have developed a novel strategy for identifying immune cells circulating in the blood that recognize specific proteins on tumor cells, a finding they believe may have potential implications for immune-based therapies.

  1. Incidence of mumps and immunity to measles, mumps and rubella among US military recruits, 2000-2004.

    Science.gov (United States)

    Eick, Angelia A; Hu, Zheng; Wang, Zhong; Nevin, Remington L

    2008-01-24

    Recent mumps outbreaks have evoked concerns of decreasing mumps immunity among adolescents and adults, including US military recruits subject to differing mumps immunization policies. To compare mumps incidence and to assess initial measles, mumps and rubella seropositivity, we conducted a cohort study among recruits from 2000 to 2004. Mumps incidence in the targeted MMR and universal MMR cohorts was 4.1 and 3.5 per 100,000 person-years, respectively, giving an incidence rate ratio of 1.16 (P=0.67). Measles, mumps, and rubella seropositivity was 84.6%, 89.5%, and 93.2%, respectively. Among recruits with measles and rubella immunity, 92.8% were mumps immune. These findings support the policy of targeting MMR immunization based upon measles and rubella serology alone.

  2. Tc17 cells mediate vaccine immunity against lethal fungal pneumonia in immune deficient hosts lacking CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Som Gowda Nanjappa

    Full Text Available Vaccines may help reduce the growing incidence of fungal infections in immune-suppressed patients. We have found that, even in the absence of CD4(+ T-cell help, vaccine-induced CD8(+ T cells persist and confer resistance against Blastomyces dermatitidis and Histoplasma capsulatum. Type 1 cytokines contribute to that resistance, but they also are dispensable. Although the role of T helper 17 cells in immunity to fungi is debated, IL-17 producing CD8(+ T cells (Tc17 cells have not been investigated. Here, we show that Tc17 cells are indispensable in antifungal vaccine immunity in hosts lacking CD4(+ T cells. Tc17 cells are induced upon vaccination, recruited to the lung on pulmonary infection, and act non-redundantly in mediating protection in a manner that requires neutrophils. Tc17 cells did not influence type I immunity, nor did the lack of IL-12 signaling augment Tc17 cells, indicating a distinct lineage and function. IL-6 was required for Tc17 differentiation and immunity, but IL-1R1 and Dectin-1 signaling was unexpectedly dispensable. Tc17 cells expressed surface CXCR3 and CCR6, but only the latter was essential in recruitment to the lung. Although IL-17 producing T cells are believed to be short-lived, effector Tc17 cells expressed low levels of KLRG1 and high levels of the transcription factor TCF-1, predicting their long-term survival and stem-cell like behavior. Our work has implications for designing vaccines against fungal infections in immune suppressed patients.

  3. Tc17 cells mediate vaccine immunity against lethal fungal pneumonia in immune deficient hosts lacking CD4+ T cells.

    Science.gov (United States)

    Nanjappa, Som Gowda; Heninger, Erika; Wüthrich, Marcel; Gasper, David Joseph; Klein, Bruce S

    2012-01-01

    Vaccines may help reduce the growing incidence of fungal infections in immune-suppressed patients. We have found that, even in the absence of CD4(+) T-cell help, vaccine-induced CD8(+) T cells persist and confer resistance against Blastomyces dermatitidis and Histoplasma capsulatum. Type 1 cytokines contribute to that resistance, but they also are dispensable. Although the role of T helper 17 cells in immunity to fungi is debated, IL-17 producing CD8(+) T cells (Tc17 cells) have not been investigated. Here, we show that Tc17 cells are indispensable in antifungal vaccine immunity in hosts lacking CD4(+) T cells. Tc17 cells are induced upon vaccination, recruited to the lung on pulmonary infection, and act non-redundantly in mediating protection in a manner that requires neutrophils. Tc17 cells did not influence type I immunity, nor did the lack of IL-12 signaling augment Tc17 cells, indicating a distinct lineage and function. IL-6 was required for Tc17 differentiation and immunity, but IL-1R1 and Dectin-1 signaling was unexpectedly dispensable. Tc17 cells expressed surface CXCR3 and CCR6, but only the latter was essential in recruitment to the lung. Although IL-17 producing T cells are believed to be short-lived, effector Tc17 cells expressed low levels of KLRG1 and high levels of the transcription factor TCF-1, predicting their long-term survival and stem-cell like behavior. Our work has implications for designing vaccines against fungal infections in immune suppressed patients.

  4. Cilia Control Vascular Mural Cell Recruitment in Vertebrates

    Directory of Open Access Journals (Sweden)

    Xiaowen Chen

    2017-01-01

    Full Text Available Vascular mural cells (vMCs are essential components of the vertebrate vascular system, controlling blood vessel maturation and homeostasis. Discrete molecular mechanisms have been associated with vMC development and differentiation. The function of hemodynamic forces in controlling vMC recruitment is unclear. Using transgenic lines marking developing vMCs in zebrafish embryos, we find that vMCs are recruited by arterial-fated vessels and that the process is flow dependent. We take advantage of tissue-specific CRISPR gene targeting to demonstrate that hemodynamic-dependent Notch activation and the ensuing arterial genetic program is driven by endothelial primary cilia. We also identify zebrafish foxc1b as a cilia-dependent Notch-specific target that is required within endothelial cells to drive vMC recruitment. In summary, we have identified a hemodynamic-dependent mechanism in the developing vasculature that controls vMC recruitment.

  5. Immune cell trafficking from the brain maintains CNS immune tolerance.

    Science.gov (United States)

    Mohammad, Mohammad G; Tsai, Vicky W W; Ruitenberg, Marc J; Hassanpour, Masoud; Li, Hui; Hart, Prue H; Breit, Samuel N; Sawchenko, Paul E; Brown, David A

    2014-03-01

    In the CNS, no pathway dedicated to immune surveillance has been characterized for preventing the anti-CNS immune responses that develop in autoimmune neuroinflammatory disease. Here, we identified a pathway for immune cells to traffic from the brain that is associated with the rostral migratory stream (RMS), which is a forebrain source of newly generated neurons. Evaluation of fluorescently labeled leukocyte migration in mice revealed that DCs travel via the RMS from the CNS to the cervical LNs (CxLNs), where they present antigen to T cells. Pharmacologic interruption of immune cell traffic with the mononuclear cell-sequestering drug fingolimod influenced anti-CNS T cell responses in the CxLNs and modulated experimental autoimmune encephalomyelitis (EAE) severity in a mouse model of multiple sclerosis (MS). Fingolimod treatment also induced EAE in a disease-resistant transgenic mouse strain by altering DC-mediated Treg functions in CxLNs and disrupting CNS immune tolerance. These data describe an immune cell pathway that originates in the CNS and is capable of dampening anti-CNS immune responses in the periphery. Furthermore, these data provide insight into how fingolimod treatment might exacerbate CNS neuroinflammation in some cases and suggest that focal therapeutic interventions, outside the CNS have the potential to selectively modify anti-CNS immunity.

  6. Mast cell activation and neutrophil recruitment promotes early and robust inflammation in the meninges in EAE.

    Science.gov (United States)

    Christy, Alison L; Walker, Margaret E; Hessner, Martin J; Brown, Melissa A

    2013-05-01

    The meninges are often considered inert tissues that house the CSF and provide protection for the brain and spinal cord. Yet emerging data demonstrates that they are also active sites of immune responses. Furthermore, the blood-CSF barrier surrounding meningeal blood vessels, together with the blood-brain barrier (BBB), is postulated to serve as a gateway for the pathological infiltration of immune cells into the CNS in multiple sclerosis (MS). Our previous studies using mast cell-deficient (Kit(W/Wv)) mice demonstrated that mast cells resident in the dura mater and pia mater exacerbate experimental autoimmune encephalomyelitis (EAE), a rodent model of MS, by facilitating CNS inflammatory cell influx. Here we examined the underlying mechanisms that mediate these effects. We demonstrate that there are dramatic alterations in immune associated gene expression in the meninges in pre-clinical disease, including those associated with mast cell and neutrophil function. Meningeal mast cells are activated within 24 h of disease induction, but do not directly compromise CNS vascular integrity. Rather, through production of TNF, mast cells elicit an early influx of neutrophils, cells known to alter vascular permeability, into the meninges. These data add to the growing evidence that inflammation in the meninges precedes CNS immune cell infiltration and establish that mast cells are among the earliest participants in these disease-initiating events. We hypothesize that mast cell-dependent neutrophil recruitment and activation in the meninges promotes early breakdown of the local BBB and CSF-blood barrier allowing initial immune cell access to the CNS.

  7. Immune cells in the female reproductive tract.

    Science.gov (United States)

    Lee, Sung Ki; Kim, Chul Jung; Kim, Dong-Jae; Kang, Jee-Hyun

    2015-02-01

    The female reproductive tract has two main functions: protection against microbial challenge and maintenance of pregnancy to term. The upper reproductive tract comprises the fallopian tubes and the uterus, including the endocervix, and the lower tract consists of the ectocervix and the vagina. Immune cells residing in the reproductive tract play contradictory roles: they maintain immunity against vaginal pathogens in the lower tract and establish immune tolerance for sperm and an embryo/fetus in the upper tract. The immune system is significantly influenced by sex steroid hormones, although leukocytes in the reproductive tract lack receptors for estrogen and progesterone. The leukocytes in the reproductive tract are distributed in either an aggregated or a dispersed form in the epithelial layer, lamina propria, and stroma. Even though immune cells are differentially distributed in each organ of the reproductive tract, the predominant immune cells are T cells, macrophages/dendritic cells, natural killer (NK) cells, neutrophils, and mast cells. B cells are rare in the female reproductive tract. NK cells in the endometrium significantly expand in the late secretory phase and further increase their number during early pregnancy. It is evident that NK cells and regulatory T (Treg) cells are extremely important in decidual angiogenesis, trophoblast migration, and immune tolerance during pregnancy. Dysregulation of endometrial/decidual immune cells is strongly related to infertility, miscarriage, and other obstetric complications. Understanding the immune system of the female reproductive tract will significantly contribute to women's health and to success in pregnancy.

  8. ``Backpack'' Functionalized Living Immune Cells

    Science.gov (United States)

    Swiston, Albert; Um, Soong Ho; Irvine, Darrell; Cohen, Robert; Rubner, Michael

    2009-03-01

    We demonstrate that functional polymeric ``backpacks'' built from polyelectrolyte multilayers (PEMs) can be attached to a fraction of the surface area of living, individual lymphocytes. Backpacks containing fluorescent polymers, superparamagnetic nanoparticles, and commercially available quantum dots have been attached to B and T-cells, which may be spatially manipulated using a magnetic field. Since the backpack does not occlude the entire cellular surface from the environment, this technique allows functional synthetic payloads to be attached to a cell that is free to perform its native functions, thereby synergistically utilizing both biological and synthetic functionalities. For instance, we have shown that backpack-modified T-cells are able to migrate on surfaces for several hours following backpack attachment. Possible payloads within the PEM backpack include drugs, vaccine antigens, thermally responsive polymers, nanoparticles, and imaging agents. We will discuss how this approach has broad potential for applications in bioimaging, single-cell functionalization, immune system and tissue engineering, and cell-based therapeutics where cell-environment interactions are critical.

  9. Innate Immune Responses in Viral Hepatitis: the role of Kupffer cells and liver-derived monocytes in shaping intrahepatic immunity in mice using the LCMV infection model

    NARCIS (Netherlands)

    D. Movita (Dowty)

    2014-01-01

    markdownabstract__Abstract__ This study was performed to elucidate the immunological role of the liver in viral hepatitis. The immune functions of the liver are shaped by the intrahepatic cells present during steady state condition, as well as the recruited immune cells during liver

  10. Innate Immune Responses in Viral Hepatitis: the role of Kupffer cells and liver-derived monocytes in shaping intrahepatic immunity in mice using the LCMV infection model

    NARCIS (Netherlands)

    D. Movita (Dowty)

    2014-01-01

    markdownabstract__Abstract__ This study was performed to elucidate the immunological role of the liver in viral hepatitis. The immune functions of the liver are shaped by the intrahepatic cells present during steady state condition, as well as the recruited immune cells during liver inflammation.

  11. Dendritic cells in peripheral tolerance and immunity

    DEFF Research Database (Denmark)

    Gad, Monika; Claesson, Mogens Helweg; Pedersen, Anders Elm

    2003-01-01

    Dendritic cells capable of influencing immunity exist as functionally distinct subsets, T cell-tolerizing and T cell-immunizing subsets. The present paper reviews how these subsets of DCs develop, differentiate and function in vivo and in vitro at the cellular and molecular level. In particular...

  12. Development of ADA Against Recombinant Human Interferon Beta in Immune Tolerant Mice Requires Rapid Recruitment of CD4(+) T Cells, Induces Formation of Germinal Centers but Lacks Susceptibility for (Most) Adjuvants

    NARCIS (Netherlands)

    Kijanka, Grzegorz; Sauerborn, Melody; Boon, Louis; Schellekens, Huub; Brinks, Vera

    2015-01-01

    Immunological processes leading to formation of antidrug antibodies (Abs) against recombinant human proteins remain poorly understood. Animal and clinical studies revealed that immunogenicity shares both T-cell-dependent (requirement of CD4(+) T cells, isotype switching) and T-cell-independent (invo

  13. CXCL13 is the major determinant for B cell recruitment to the CSF during neuroinflammation

    Directory of Open Access Journals (Sweden)

    Kowarik Markus C

    2012-05-01

    Full Text Available Abstract Background The chemokines and cytokines CXCL13, CXCL12, CCL19, CCL21, BAFF and APRIL are believed to play a role in the recruitment of B cells to the central nervous system (CNS compartment during neuroinflammation. To determine which chemokines/cytokines show the strongest association with a humoral immune response in the cerebrospinal fluid (CSF, we measured their concentrations in the CSF and correlated them with immune cell subsets and antibody levels. Methods Cytokine/chemokine concentrations were measured in CSF and serum by ELISA in patients with non-inflammatory neurological diseases (NIND, n = 20, clinically isolated syndrome (CIS, n = 30, multiple sclerosis (MS, n = 20, Lyme neuroborreliosis (LNB, n = 8 and patients with other inflammatory neurological diseases (OIND, n = 30. Albumin, IgG, IgA and IgM were measured by nephelometry. CSF immune cell subsets were determined by seven-color flow cytometry. Results CXCL13 was significantly elevated in the CSF of all patient groups with inflammatory diseases. BAFF levels were significantly increased in patients with LNB and OIND. CXCL12 was significantly elevated in patients with LNB. B cells and plasmablasts were significantly elevated in the CSF of all patients with inflammatory diseases. CXCL13 showed the most consistent correlation with CSF B cells, plasmablasts and intrathecal Ig synthesis. Conclusions CXCL13 seems to be the major determinant for B cell recruitment to the CNS compartment in different neuroinflammatory diseases. Thus, elevated CSF CXCL13 levels rather reflect a strong humoral immune response in the CNS compartment than being specific for a particular disease entity.

  14. FOXP3+ T Cells Recruited to Sites of Sterile Skeletal Muscle Injury Regulate the Fate of Satellite Cells and Guide Effective Tissue Regeneration

    OpenAIRE

    Alessandra Castiglioni; Gianfranca Corna; Elena Rigamonti; Veronica Basso; Michela Vezzoli; Antonella Monno; Almada, Albert E; Anna Mondino; Wagers, Amy J.; Angelo A. Manfredi; Patrizia Rovere-Querini

    2015-01-01

    Muscle injury induces a classical inflammatory response in which cells of the innate immune system rapidly invade the tissue. Macrophages are prominently involved in this response and required for proper healing, as they are known to be important for clearing cellular debris and supporting satellite cell differentiation. Here, we sought to assess the role of the adaptive immune system in muscle regeneration after acute damage. We show that T lymphocytes are transiently recruited into the musc...

  15. Immune cell interplay in colorectal cancer prognosis

    Institute of Scientific and Technical Information of China (English)

    Samuel; E; Norton; Kirsten; A; Ward-Hartstonge; Edward; S; Taylor; Roslyn; A; Kemp

    2015-01-01

    The immune response to colorectal cancer has proven to be a reliable measure of patient outcome in several studies. However, the complexity of the immune response in this disease is not well understood, par-ticularly the interactions between tumour-associated cells and cells of the innate and adaptive immune system. This review will discuss the relationship betweencancer associated fibroblasts and macrophages, as well as between macrophages and T cells, and demonstrate how each population may support or prevent tumour growth in a different immune environment.

  16. Strategies for recruitment of stem cells to treat myocardial infarction.

    Science.gov (United States)

    Shafiq, Muhammad; Lee, Sang-Hoon; Jung, Youngmee; Kim, Soo Hyun

    2015-01-01

    Heart failure is one of the most prominent causes of morbidity and mortality worldwide. According to the World Health Organization, coronary artery disease and myocardial infarction (MI) are responsible for 29% of deaths worldwide. MI results in obstruction of the blood supply to the heart and scar formation, and causes substantial death of cardiomyocytes in the infarct zone followed by an inflammatory response. Current treatment methodologies of MI and heart failure include organ transplantation, coronary artery bypass grafting, ventricular remodeling, cardiomyoplasty, and cellular therapy. Each of these methodologies has associated risks and benefits. Cellular cardiomyoplasty is a viable option to decrease the fibrosis of infarct scars, adverse post-ischemic remodeling, and improve heart function. However, the low rate of cell survival, shortage of cell sources and donors, tumorigenesis, and ethical issues hamper full exploitation of cell therapy for MI treatment. Consequently, the mobilization and recruitment of endogenous stem/progenitor cells from bone marrow, peripheral circulation, and cardiac tissues has immense potential through harnessing the host's own reparative capacities that result from interplay among cytokines, chemokines, and adhesion molecules. Therapeutic treatments to enhance the mobilization and homing of stem cells are under development. In this review, we present state-of-the-art approaches that are being pursued for stem cell mobilization and recruitment to regenerate infarcted myocardium. Potential therapeutic interventions and delivery strategies are discussed in detail.

  17. Orchestration of angiogenesis by immune cells

    Directory of Open Access Journals (Sweden)

    Antonino eBruno

    2014-07-01

    Full Text Available It is widely accepted that the tumor microenvironment plays a major role in cancer and is indispensable for tumor progression. The tumor microenvironment involves many players going well beyond the malignant-transformed cells, including stromal, immune and endothelial cells. The non-malignant cells can acquire tumor-promoting functions during carcinogenesis. In particular, these cells can orchestrate the symphony of the angiogenic switch, permitting the creation of new blood vessels that allows rapid expansion and progression toward malignancy.Considerable attention within the context of tumor angiogenesis should focus not only on the endothelial cells, representing a fundamental unit, but also on immune cells and on the inflammatory tumor infiltrate. Immune cells infiltrating tumors typically show a tumor-induced polarization associated with attenuation of anti-tumor functions and generation of pro-tumor activities, among these angiogenesis. Here we propose a scenario suggesting that the angiogenic switch is an immune switch arising from the pro-angiogenic polarization of immune cells. This view links immunity, inflammation and angiogenesis to tumor progression. Here we review the data in the literature and seek to identify the conductors of this orchestra. We also suggest that interrupting the immune -> inflammation -> angiogenesis -> tumor progression process can delay or prevent tumor insurgence and malignant disease.

  18. DMPD: Signals and receptors involved in recruitment of inflammatory cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 7744810 Signals and receptors involved in recruitment of inflammatory cells. Ben-Ba...ow Signals and receptors involved in recruitment of inflammatory cells. PubmedID 7744810 Title Signals and receptors involved in recr

  19. [Immune system evolution. (From cells to humans)].

    Science.gov (United States)

    Belek, A S

    1992-01-01

    The great variety of cells and molecules observed in the mammalian immune system can be explained by stepwise acquisition of them during phylogeny. Self/nonself discrimination and cell-mediated immunity have been present since the early stages of evolution. Although some inducible antimicrobial molecules have been demonstrated in invertebrates, immunoglobulins appear in vertebrates. T and B cell diversity, development of the lymphoid organs, MHC molecules, complement and cytokines are the characteristics that appear through the evolution of vertebrates. Further knowledge that will be obtained from phylogenetic studies will improve our understanding of the immune system of human.

  20. Cytomegalovirus immune evasion of myeloid lineage cells.

    Science.gov (United States)

    Brinkmann, Melanie M; Dağ, Franziska; Hengel, Hartmut; Messerle, Martin; Kalinke, Ulrich; Čičin-Šain, Luka

    2015-06-01

    Cytomegalovirus (CMV) evades the immune system in many different ways, allowing the virus to grow and its progeny to spread in the face of an adverse environment. Mounting evidence about the antiviral role of myeloid immune cells has prompted the research of CMV immune evasion mechanisms targeting these cells. Several cells of the myeloid lineage, such as monocytes, dendritic cells and macrophages, play a role in viral control, but are also permissive for CMV and are naturally infected by it. Therefore, CMV evasion of myeloid cells involves mechanisms that qualitatively differ from the evasion of non-CMV-permissive immune cells of the lymphoid lineage. The evasion of myeloid cells includes effects in cis, where the virus modulates the immune signaling pathways within the infected myeloid cell, and those in trans, where the virus affects somatic cells targeted by cytokines released from myeloid cells. This review presents an overview of CMV strategies to modulate and evade the antiviral activity of myeloid cells in cis and in trans.

  1. T cell immunity using transgenic B lymphocytes

    Science.gov (United States)

    Gerloni, Mara; Rizzi, Marta; Castiglioni, Paola; Zanetti, Maurizio

    2004-03-01

    Adaptive immunity exists in all vertebrates and plays a defense role against microbial pathogens and tumors. T cell responses begin when precursor T cells recognize antigen on specialized antigen-presenting cells and differentiate into effector cells. Currently, dendritic cells are considered the only cells capable of stimulating T lymphocytes. Here, we show that mature naïve B lymphocytes can be genetically programmed by using nonviral DNA and turned into powerful antigen-presenting cells with a dual capacity of synthesis and presentation of antigen to T cells in vivo. A single i.v. injection of transgenic lymphocytes activates T cell responses reproducibly and specifically even at very low cell doses (102). We also demonstrate that T cell priming can occur in the absence of dendritic cells and results in immunological memory with protective effector functions. These findings disclose aspects in the regulation of adaptive immunity and indicate possibilities for vaccination against viruses and cancer in humans.

  2. Cell mediated immunity to fungi: a reassessment.

    Science.gov (United States)

    Romani, Luigina

    2008-09-01

    Protective immunity against fungal pathogens is achieved by the integration of two distinct arms of the immune system, the innate and adaptive responses. Innate and adaptive immune responses are intimately linked and controlled by sets of molecules and receptors that act to generate the most effective form of immunity for protection against fungal pathogens. The decision of how to respond will still be primarily determined by interactions between pathogens and cells of the innate immune system, but the actions of T cells will feed back into this dynamic equilibrium to regulate the balance between tolerogenic and inflammatory responses. In the last two decades, the immunopathogenesis of fungal infections and fungal diseases was explained primarily in terms of Th1/Th2 balance. Although Th1 responses driven by the IL-12/IFN-gamma axis are central to protection against fungi, other cytokines and T cell-dependent pathways have come of age. The newly described Th17 developmental pathway may play an inflammatory role previously attributed to uncontrolled Th1 responses and serves to accommodate the seemingly paradoxical association of chronic inflammatory responses with fungal persistence in the face of an ongoing inflammation. Regulatory T cells in their capacity to inhibit aspects of innate and adaptive antifungal immunity have become an integral component of immune resistance to fungi, and provide the host with immune defense mechanisms adequate for protection, without necessarily eliminating fungal pathogens which would impair immune memory--or causing an unacceptable level of tissue damage. The enzyme indoleamine 2,3-dioxygenase and tryptophan metabolites contribute to immune homeostasis by inducing Tregs and taming overzealous or heightened inflammatory responses.

  3. T cells and the humoral immune system

    NARCIS (Netherlands)

    W.B. van Muiswinkel (Willem)

    1975-01-01

    textabstractLymphoid cells and macrophages play an important role in the development and rnaintance of humoral and cellular immunity in mammals. The lymphoid cells in the peripheral lymphoid organs are divided into two major classes: (1) thymus-derived lymphocytes or T cells and (2) bursa-equivalent

  4. T cells and the humoral immune system

    NARCIS (Netherlands)

    W.B. van Muiswinkel (Willem)

    1975-01-01

    textabstractLymphoid cells and macrophages play an important role in the development and rnaintance of humoral and cellular immunity in mammals. The lymphoid cells in the peripheral lymphoid organs are divided into two major classes: (1) thymus-derived lymphocytes or T cells and (2) bursa-equivalent

  5. Myeloid cells in tumour-immune interactions.

    Science.gov (United States)

    Kareva, Irina; Berezovskaya, Faina; Castillo-Chavez, Carlos

    2010-07-01

    Despite highly developed specific immune responses, tumour cells often manage to escape recognition by the immune system, continuing to grow uncontrollably. Experimental work suggests that mature myeloid cells may be central to the activation of the specific immune response. Recognition and subsequent control of tumour growth by the cells of the specific immune response depend on the balance between immature (ImC) and mature (MmC) myeloid cells in the body. However, tumour cells produce cytokines that inhibit ImC maturation, altering the balance between ImC and MmC. Hence, the focus of this manuscript is on the study of the potential role of this inhibiting mechanism on tumour growth dynamics. A conceptual predator-prey type model that incorporates the dynamics and interactions of tumour cells, CD8(+) T cells, ImC and MmC is proposed in order to address the role of this mechanism. The prey (tumour) has a defence mechanism (blocking the maturation of ImC) that prevents the predator (immune system) from recognizing it. The model, a four-dimensional nonlinear system of ordinary differential equations, is reduced to a two-dimensional system using time-scale arguments that are tied to the maturation rate of ImC. Analysis shows that the model is capable of supporting biologically reasonable patterns of behaviour depending on the initial conditions. A range of parameters, where healing without external influences can occur, is identified both qualitatively and quantitatively.

  6. Targeting epidermal Langerhans cells by epidermal powder immunization

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Immune reactions to foreign or self-antigens lead to protective immunity and, sometimes, immune disorders such as allergies and autoimmune diseases. Antigen presenting cells (APC) including epidermal Langerhans cells (LCs) play an important role in the course and outcome of the immune reactions. Epidermal powder immunization (EPI) is a technology that offers a tool to manipulate the LCs and the potential to harness the immune reactions towards prevention and treatment of infectious diseases and immune disorders.

  7. An Immune Atlas of Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Chevrier, Stéphane; Levine, Jacob Harrison; Zanotelli, Vito Riccardo Tomaso; Silina, Karina; Schulz, Daniel; Bacac, Marina; Ries, Carola Hermine; Ailles, Laurie; Jewett, Michael Alexander Spencer; Moch, Holger; van den Broek, Maries; Beisel, Christian; Stadler, Michael Beda; Gedye, Craig; Reis, Bernhard; Pe'er, Dana; Bodenmiller, Bernd

    2017-05-04

    Immune cells in the tumor microenvironment modulate cancer progression and are attractive therapeutic targets. Macrophages and T cells are key components of the microenvironment, yet their phenotypes and relationships in this ecosystem and to clinical outcomes are ill defined. We used mass cytometry with extensive antibody panels to perform in-depth immune profiling of samples from 73 clear cell renal cell carcinoma (ccRCC) patients and five healthy controls. In 3.5 million measured cells, we identified 17 tumor-associated macrophage phenotypes, 22 T cell phenotypes, and a distinct immune composition correlated with progression-free survival, thereby presenting an in-depth human atlas of the immune tumor microenvironment in this disease. This study revealed potential biomarkers and targets for immunotherapy development and validated tools that can be used for immune profiling of other tumor types. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Cellular immune responses towards regulatory cells.

    Science.gov (United States)

    Larsen, Stine Kiær

    2016-01-01

    This thesis describes the results from two published papers identifying spontaneous cellular immune responses against the transcription factors Foxp3 and Foxo3. The tumor microenvironment is infiltrated by cells that hinder effective tumor immunity from developing. Two of these cell types, which have been linked to a bad prognosis for patients, are regulatory T cells (Treg) and tolerogenic dendritic cells (DC). Tregs inhibit effector T cells from attacking the tumor through various mechanisms, including secreted factors and cell-to-cell contact. Tregs express the transcription factor Foxp3, which is necessary for their development and suppressive activities. Tolerogenic DCs participate in creating an environment in the tumor where effector T cells become tolerant towards the tumor instead of attacking it. The transcription factor Foxo3 was recently described to be highly expressed by tolerogenic DCs and to programme their tolerogenic influence. This thesis describes for the first time the existence of spontaneous cellular immune responses against peptides derived from Foxp3 and Foxo3. We have detected the presence of cytotoxic T cells that recognise these peptides in an HLA-A2 restricted manner in cancer patients and for Foxp3 in healthy donors as well. In addition, we have demonstrated that the Foxp3- and Foxo3-specific CTLs recognize Foxp3- and Foxo3-expressing cancer cell lines and importantly, suppressive immune cells, namely Tregs and in vitro generated DCs. Cancer immunotherapy is recently emerging as an important treatment modality improving the survival of selected patients. The current progress is largely owing to targeting of the immune suppressive milieu that is dominating the tumor microenvironment. This is being done through immune checkpoint blockade with CTLA-4 and PD-1/PD-L1 antibodies and through lymphodepleting conditioning of patients and ex vivo activation of TILs in adoptive cell transfer. Several strategies are being explored for depletion of

  9. Obesity induced by a high-fat diet is associated with increased immune cell entry into the central nervous system.

    Science.gov (United States)

    Buckman, Laura B; Hasty, Alyssa H; Flaherty, David K; Buckman, Christopher T; Thompson, Misty M; Matlock, Brittany K; Weller, Kevin; Ellacott, Kate L J

    2014-01-01

    Obesity is associated with chronic low-grade inflammation in peripheral tissues caused, in part, by the recruitment of inflammatory monocytes into adipose tissue. Studies in rodent models have also shown increased inflammation in the central nervous system (CNS) during obesity. The goal of this study was to determine whether obesity is associated with recruitment of peripheral immune cells into the CNS. To do this we used a bone marrow chimerism model to track the entry of green-fluorescent protein (GFP) labeled peripheral immune cells into the CNS. Flow cytometry was used to quantify the number of GFP(+) immune cells recruited into the CNS of mice fed a high-fat diet compared to standard chow fed controls. High-fat feeding resulted in obesity associated with a 30% increase in the number of GFP(+) cells in the CNS compared to control mice. Greater than 80% of the GFP(+) cells recruited to the CNS were also CD45(+) CD11b(+) indicating that the GFP(+) cells displayed characteristics of microglia/macrophages. Immunohistochemistry further confirmed the increase in GFP(+) cells in the CNS of the high-fat fed group and also indicated that 93% of the recruited cells were found in the parenchyma and had a stellate morphology. These findings indicate that peripheral immune cells can be recruited to the CNS in obesity and may contribute to the inflammatory response.

  10. Regulation of angiogenesis, mural cell recruitment and adventitial macrophage behavior by Toll-like receptors.

    Science.gov (United States)

    Aplin, Alfred C; Ligresti, Giovanni; Fogel, Eric; Zorzi, Penelope; Smith, Kelly; Nicosia, Roberto F

    2014-01-01

    The angiogenic response to injury can be studied by culturing rat or mouse aortic explants in collagen gels. Gene expression studies show that aortic angiogenesis is preceded by an immune reaction with overexpression of Toll-like receptors (TLRs) and TLR-inducible genes. TLR1, 3, and 6 are transiently upregulated at 24 h whereas TLR2, 4, and 8 expression peaks at 24 h but remains elevated during angiogenesis and vascular regression. Expression of TLR5, 7 and 9 steadily increases over time and is highest during vascular regression. Studies with isolated cells show that TLRs are expressed at higher levels in aortic macrophages compared to endothelial or mural cells with the exception of TLR2 and TLR9 which are more abundant in the aortic endothelium. LPS and other TLR ligands dose dependently stimulate angiogenesis and vascular endothelial growth factor production. TLR9 ligands also influence the behavior of nonendothelial cell types by blocking mural cell recruitment and inducing formation of multinucleated giant cells by macrophages. TLR9-induced mural cell depletion is associated with reduced expression of the mural cell recruiting factor PDGFB. The spontaneous angiogenic response of the aortic rings to injury is reduced in cultures from mice deficient in myeloid differentiation primary response 88 (MyD88), a key adapter molecule of TLRs, and following treatment with an inhibitor of the NFκB pathway. These results suggest that the TLR system participates in the angiogenic response of the vessel wall to injury and may play an important role in the regulation of inflammatory angiogenesis in reactive and pathologic processes.

  11. Innate immune response to pulmonary contusion: Identification of cell-type specific inflammatory responses

    OpenAIRE

    Hoth, J. Jason; Wells, Jonathan D.; Yoza, Barbara K.; McCall, Charles E.

    2012-01-01

    Lung injury from pulmonary contusion is a common traumatic injury, predominantly seen after blunt chest trauma such as in vehicular accidents. The local and systemic inflammatory response to injury includes activation of innate immune receptors, elaboration of a variety inflammatory mediators, and recruitment of inflammatory cells to the injured lung. Using a mouse model of pulmonary contusion, we had previously shown that innate immune Toll like receptors 2 and 4 (TLR2 and TLR4) mediate the ...

  12. Epigenetic Dysfunction in Turner Syndrome Immune Cells.

    Science.gov (United States)

    Thrasher, Bradly J; Hong, Lee Kyung; Whitmire, Jason K; Su, Maureen A

    2016-05-01

    Turner syndrome (TS) is a chromosomal condition associated with partial or complete absence of the X chromosome that involves characteristic findings in multiple organ systems. In addition to well-known clinical characteristics such as short stature and gonadal failure, TS is also associated with T cell immune alterations and chronic otitis media, suggestive of a possible immune deficiency. Recently, ubiquitously transcribed tetratricopeptide repeat on the X chromosome (UTX), a histone H3 lysine 27 (H3K27) demethylase, has been identified as a downregulated gene in TS immune cells. Importantly, UTX is an X-linked gene that escapes X-chromosome inactivation and thus is haploinsufficient in TS. Mice with T cell-specific UTX deficiency have impaired clearance of chronic viral infection due to decreased frequencies of T follicular helper (Tfh) cells, which are critical for B cell antibody generation. In parallel, TS patients have decreased Tfh frequencies in peripheral blood. Together, these findings suggest that haploinsufficiency of the X-linked UTX gene in TS T cells underlies an immune deficit, which may manifest as increased predisposition to chronic otitis media.

  13. Measurement of myeloid cell immune suppressive activity.

    Science.gov (United States)

    Dolcetti, Luigi; Peranzoni, Elisa; Bronte, Vincenzo

    2010-11-01

    This unit presents simple methods to assess the immunosuppressive properties of immunoregulatory cells of myeloid origin, such as myeloid-derived suppressor cells (MDSCs), both in vitro and in vivo. These methods are general and could be adapted to test the impact of different suppressive populations on T cell activation, proliferation, and cytotoxic activity; moreover they could be useful to assess the influence exerted on immune suppressive pathways by genetic modifications, chemical inhibitors, and drugs.

  14. Innate lymphoid cells in inflammation and immunity.

    Science.gov (United States)

    McKenzie, Andrew N J; Spits, Hergen; Eberl, Gerard

    2014-09-18

    Innate lymphoid cells (ILCs) were first described as playing important roles in the development of lymphoid tissues and more recently in the initiation of inflammation at barrier surfaces in response to infection or tissue damage. It has now become apparent that ILCs play more complex roles throughout the duration of immune responses, participating in the transition from innate to adaptive immunity and contributing to chronic inflammation. The proximity of ILCs to epithelial surfaces and their constitutive strategic positioning in other tissues throughout the body ensures that, in spite of their rarity, ILCs are able to regulate immune homeostasis effectively. Dysregulation of ILC function might result in chronic pathologies such as allergies, autoimmunity, and inflammation. A new role for ILCs in the maintenance of metabolic homeostasis has started to emerge, underlining their importance in fundamental physiological processes beyond infection and immunity. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. The Role of NK Cell in T Cell Recruitment in Murine Liver Infected with Adenovirus

    Institute of Scientific and Technical Information of China (English)

    游上游; 艾洪武; 黄巍; 张楚瑜

    2003-01-01

    To study the role of natural killer (NK) cells in T cell recruitment in murine liver infected with virus, mice wereintravenously injected daily with anti-NK1.1+ antibody to deplete NK cells. Lymphocytes in the liver tissue of mice infectedwith type 5 adenovirus depleted in the E1 and E3 regions were assessed by fluorometric activated cell sorting (FACS). Ex-pression of chemokine IP-10 and its receptor CXCR3 mRNA in the liver, hepatic lymphocytes and spleen tissue were examined by reverse transcription polymerase chain reaction (RT-PCR). Serum almfine aminotransferase (ALT) was measured asan indicator of liver injury. It was found that infection of adenovims and anfi-Fas monoclonal antibody (mAb) into mice caused liver injury and high expression of interfemn-γ inducible protein-10 (IP-10) mRNA in the liver. Anfi-NK1.1+ mAb, which was intraperitoneally injected into the mice infected with adenovirus, suppresses T cell recruitment and expression of IP-10 mRNA in the hver. Slighter hver injury was also observed. After vires infection, expression of CXCR3 mRNAin spleen and hver tissue was observed at different time. The results suggested that T cell recruitment was initiated by NKcell dependent chemokine IP-10, which induced activated T cells priming in the spleen to the hver of the mouse. NK cells played a key role in T cell recruitment in the liver of mouse infected with adenovims.

  16. Random migration and signal integration promote rapid and robust T cell recruitment.

    Science.gov (United States)

    Textor, Johannes; Henrickson, Sarah E; Mandl, Judith N; von Andrian, Ulrich H; Westermann, Jürgen; de Boer, Rob J; Beltman, Joost B

    2014-08-01

    To fight infections, rare T cells must quickly home to appropriate lymph nodes (LNs), and reliably localize the antigen (Ag) within them. The first challenge calls for rapid trafficking between LNs, whereas the second may require extensive search within each LN. Here we combine simulations and experimental data to investigate which features of random T cell migration within and between LNs allow meeting these two conflicting demands. Our model indicates that integrating signals from multiple random encounters with Ag-presenting cells permits reliable detection of even low-dose Ag, and predicts a kinetic feature of cognate T cell arrest in LNs that we confirm using intravital two-photon data. Furthermore, we obtain the most reliable retention if T cells transit through LNs stochastically, which may explain the long and widely distributed LN dwell times observed in vivo. Finally, we demonstrate that random migration, both between and within LNs, allows recruiting the majority of cognate precursors within a few days for various realistic infection scenarios. Thus, the combination of two-scale stochastic migration and signal integration is an efficient and robust strategy for T cell immune surveillance.

  17. Random migration and signal integration promote rapid and robust T cell recruitment.

    Directory of Open Access Journals (Sweden)

    Johannes Textor

    2014-08-01

    Full Text Available To fight infections, rare T cells must quickly home to appropriate lymph nodes (LNs, and reliably localize the antigen (Ag within them. The first challenge calls for rapid trafficking between LNs, whereas the second may require extensive search within each LN. Here we combine simulations and experimental data to investigate which features of random T cell migration within and between LNs allow meeting these two conflicting demands. Our model indicates that integrating signals from multiple random encounters with Ag-presenting cells permits reliable detection of even low-dose Ag, and predicts a kinetic feature of cognate T cell arrest in LNs that we confirm using intravital two-photon data. Furthermore, we obtain the most reliable retention if T cells transit through LNs stochastically, which may explain the long and widely distributed LN dwell times observed in vivo. Finally, we demonstrate that random migration, both between and within LNs, allows recruiting the majority of cognate precursors within a few days for various realistic infection scenarios. Thus, the combination of two-scale stochastic migration and signal integration is an efficient and robust strategy for T cell immune surveillance.

  18. Lymph node trafficking of regulatory T cells is prerequisite for immune suppression.

    Science.gov (United States)

    Huang, Miao-Tzu; Lin, Been-Ren; Liu, Wei-Liang; Lu, Chun-Wei; Chiang, Bor-Luen

    2016-04-01

    Regulatory T cells have a crucial role in health and disease because of their immune regulation function. However, the anatomic sites where regulatory T cells exert optimal immune regulation are open to debate. In our current study with the use of a shear-stress flow assay, we found that regulatory T cells exhibited significantly decreased adhesion to either activated endothelial monolayer or intercellular adhesion molecule 1 or E-selectin-coated surfaces compared with activated effector T cells. The less transmigration capacity of the regulatory T cells prompted our speculation of preferential lymph node localization for the regulatory T cells that endowed these cells with immune regulation function in the most efficient manner. To test this hypothesis, the role of lymph node localization in regulatory T cell-mediated immune suppression was evaluated with a footpad inflammation model. We found that adoptively transferred regulatory T cells inhibited the development of footpad inflammation. In addition, although blockage of CCR7 or CD62L had no effect on the immune suppressive function of the regulatory T cells per se, pretreatment of the regulatory T cells with either CCR7 or CD62L blocking antibodies prevented their recruitment into draining lymph nodes and concomitantly abrogated the immune suppressive effects of adoptively transferred regulatory T cells during footpad inflammation. Our data demonstrate the crucial role of lymph node localization in regulatory T cell-mediated immune suppression and suggest a probable hierarchy in the anatomic sites for optimal immune regulation. Elucidating the relationships between the transmigration characteristics of the regulatory T cells and their immune regulation function will provide insightful information for regulatory T cell-based cell therapy.

  19. Gut Mesenchymal Stromal Cells in Immunity

    Directory of Open Access Journals (Sweden)

    Valeria Messina

    2017-01-01

    Full Text Available Mesenchymal stromal cells (MSCs, first found in bone marrow (BM, are the structural architects of all organs, participating in most biological functions. MSCs possess tissue-specific signatures that allow their discrimination according to their origin and location. Among their multiple functions, MSCs closely interact with immune cells, orchestrating their activity to maintain overall homeostasis. The phenotype of tissue MSCs residing in the bowel overlaps with myofibroblasts, lining the bottom walls of intestinal crypts (pericryptal or interspersed within intestinal submucosa (intercryptal. In Crohn’s disease, intestinal MSCs are tightly stacked in a chronic inflammatory milieu, which causes their enforced expression of Class II major histocompatibility complex (MHC. The absence of Class II MHC is a hallmark for immune-modulator and tolerogenic properties of normal MSCs and, vice versa, the expression of HLA-DR is peculiar to antigen presenting cells, that is, immune-activator cells. Interferon gamma (IFNγ is responsible for induction of Class II MHC expression on intestinal MSCs. The reversal of myofibroblasts/MSCs from an immune-modulator to an activator phenotype in Crohn’s disease results in the formation of a fibrotic tube subverting the intestinal structure. Epithelial metaplastic areas in this context can progress to dysplasia and cancer.

  20. Gut Mesenchymal Stromal Cells in Immunity

    Science.gov (United States)

    Messina, Valeria; Buccione, Carla; Marotta, Giulia; Ziccheddu, Giovanna; Signore, Michele; Mattia, Gianfranco; Puglisi, Rossella; Sacchetti, Benedetto; Biancone, Livia

    2017-01-01

    Mesenchymal stromal cells (MSCs), first found in bone marrow (BM), are the structural architects of all organs, participating in most biological functions. MSCs possess tissue-specific signatures that allow their discrimination according to their origin and location. Among their multiple functions, MSCs closely interact with immune cells, orchestrating their activity to maintain overall homeostasis. The phenotype of tissue MSCs residing in the bowel overlaps with myofibroblasts, lining the bottom walls of intestinal crypts (pericryptal) or interspersed within intestinal submucosa (intercryptal). In Crohn's disease, intestinal MSCs are tightly stacked in a chronic inflammatory milieu, which causes their enforced expression of Class II major histocompatibility complex (MHC). The absence of Class II MHC is a hallmark for immune-modulator and tolerogenic properties of normal MSCs and, vice versa, the expression of HLA-DR is peculiar to antigen presenting cells, that is, immune-activator cells. Interferon gamma (IFNγ) is responsible for induction of Class II MHC expression on intestinal MSCs. The reversal of myofibroblasts/MSCs from an immune-modulator to an activator phenotype in Crohn's disease results in the formation of a fibrotic tube subverting the intestinal structure. Epithelial metaplastic areas in this context can progress to dysplasia and cancer. PMID:28337224

  1. FOXP3+ T Cells Recruited to Sites of Sterile Skeletal Muscle Injury Regulate the Fate of Satellite Cells and Guide Effective Tissue Regeneration

    Science.gov (United States)

    Castiglioni, Alessandra; Basso, Veronica; Vezzoli, Michela; Monno, Antonella; Almada, Albert E.; Mondino, Anna; Wagers, Amy J.; Manfredi, Angelo A.; Rovere-Querini, Patrizia

    2015-01-01

    Muscle injury induces a classical inflammatory response in which cells of the innate immune system rapidly invade the tissue. Macrophages are prominently involved in this response and required for proper healing, as they are known to be important for clearing cellular debris and supporting satellite cell differentiation. Here, we sought to assess the role of the adaptive immune system in muscle regeneration after acute damage. We show that T lymphocytes are transiently recruited into the muscle after damage and appear to exert a pro-myogenic effect on muscle repair. We observed a decrease in the cross-sectional area of regenerating myofibers after injury in Rag2-/- γ-chain-/- mice, as compared to WT controls, suggesting that T cell recruitment promotes muscle regeneration. Skeletal muscle infiltrating T lymphocytes were enriched in CD4+CD25+FOXP3+ cells. Direct exposure of muscle satellite cells to in vitro induced Treg cells effectively enhanced their expansion, and concurrently inhibited their myogenic differentiation. In vivo, the recruitment of Tregs to acutely injured muscle was limited to the time period of satellite expansion, with possibly important implications for situations in which inflammatory conditions persist, such as muscular dystrophies and inflammatory myopathies. We conclude that the adaptive immune system, in particular T regulatory cells, is critically involved in effective skeletal muscle regeneration. Thus, in addition to their well-established role as regulators of the immune/inflammatory response, T regulatory cells also regulate the activity of skeletal muscle precursor cells, and are instrumental for the proper regeneration of this tissue. PMID:26039259

  2. FOXP3+ T Cells Recruited to Sites of Sterile Skeletal Muscle Injury Regulate the Fate of Satellite Cells and Guide Effective Tissue Regeneration.

    Directory of Open Access Journals (Sweden)

    Alessandra Castiglioni

    Full Text Available Muscle injury induces a classical inflammatory response in which cells of the innate immune system rapidly invade the tissue. Macrophages are prominently involved in this response and required for proper healing, as they are known to be important for clearing cellular debris and supporting satellite cell differentiation. Here, we sought to assess the role of the adaptive immune system in muscle regeneration after acute damage. We show that T lymphocytes are transiently recruited into the muscle after damage and appear to exert a pro-myogenic effect on muscle repair. We observed a decrease in the cross-sectional area of regenerating myofibers after injury in Rag2-/- γ-chain-/- mice, as compared to WT controls, suggesting that T cell recruitment promotes muscle regeneration. Skeletal muscle infiltrating T lymphocytes were enriched in CD4+CD25+FOXP3+ cells. Direct exposure of muscle satellite cells to in vitro induced Treg cells effectively enhanced their expansion, and concurrently inhibited their myogenic differentiation. In vivo, the recruitment of Tregs to acutely injured muscle was limited to the time period of satellite expansion, with possibly important implications for situations in which inflammatory conditions persist, such as muscular dystrophies and inflammatory myopathies. We conclude that the adaptive immune system, in particular T regulatory cells, is critically involved in effective skeletal muscle regeneration. Thus, in addition to their well-established role as regulators of the immune/inflammatory response, T regulatory cells also regulate the activity of skeletal muscle precursor cells, and are instrumental for the proper regeneration of this tissue.

  3. FOXP3+ T Cells Recruited to Sites of Sterile Skeletal Muscle Injury Regulate the Fate of Satellite Cells and Guide Effective Tissue Regeneration.

    Science.gov (United States)

    Castiglioni, Alessandra; Corna, Gianfranca; Rigamonti, Elena; Basso, Veronica; Vezzoli, Michela; Monno, Antonella; Almada, Albert E; Mondino, Anna; Wagers, Amy J; Manfredi, Angelo A; Rovere-Querini, Patrizia

    2015-01-01

    Muscle injury induces a classical inflammatory response in which cells of the innate immune system rapidly invade the tissue. Macrophages are prominently involved in this response and required for proper healing, as they are known to be important for clearing cellular debris and supporting satellite cell differentiation. Here, we sought to assess the role of the adaptive immune system in muscle regeneration after acute damage. We show that T lymphocytes are transiently recruited into the muscle after damage and appear to exert a pro-myogenic effect on muscle repair. We observed a decrease in the cross-sectional area of regenerating myofibers after injury in Rag2-/- γ-chain-/- mice, as compared to WT controls, suggesting that T cell recruitment promotes muscle regeneration. Skeletal muscle infiltrating T lymphocytes were enriched in CD4+CD25+FOXP3+ cells. Direct exposure of muscle satellite cells to in vitro induced Treg cells effectively enhanced their expansion, and concurrently inhibited their myogenic differentiation. In vivo, the recruitment of Tregs to acutely injured muscle was limited to the time period of satellite expansion, with possibly important implications for situations in which inflammatory conditions persist, such as muscular dystrophies and inflammatory myopathies. We conclude that the adaptive immune system, in particular T regulatory cells, is critically involved in effective skeletal muscle regeneration. Thus, in addition to their well-established role as regulators of the immune/inflammatory response, T regulatory cells also regulate the activity of skeletal muscle precursor cells, and are instrumental for the proper regeneration of this tissue.

  4. Platelets as immune cells in infectious diseases.

    Science.gov (United States)

    Speth, Cornelia; Löffler, Jürgen; Krappmann, Sven; Lass-Flörl, Cornelia; Rambach, Günter

    2013-11-01

    Platelets have been shown to cover a broad range of functions. Besides their role in hemostasis, they have immunological functions and thus participate in the interaction between pathogens and host defense. Platelets have a broad repertoire of receptor molecules that enable them to sense invading pathogens and infection-induced inflammation. Consequently, platelets exert antimicrobial effector mechanisms, but also initiate an intense crosstalk with other arms of the innate and adaptive immunity, including neutrophils, monocytes/macrophages, dendritic cells, B cells and T cells. There is a fragile balance between beneficial antimicrobial effects and detrimental reactions that contribute to the pathogenesis, and many pathogens have developed mechanisms to influence these two outcomes. This review aims to highlight aspects of the interaction strategies between platelets and pathogenic bacteria, viruses, fungi and parasites, in addition to the subsequent networking between platelets and other immune cells, and the relevance of these processes for the pathogenesis of infections.

  5. Recruitment of calcineurin to the TCR positively regulates T cell activation.

    Science.gov (United States)

    Dutta, Debjani; Barr, Valarie A; Akpan, Itoro; Mittelstadt, Paul R; Singha, Laishram I; Samelson, Lawrence E; Ashwell, Jonathan D

    2017-02-01

    Calcineurin is a phosphatase whose primary targets in T cells are NFAT transcription factors, and inhibition of calcineurin activity by treatment with cyclosporin A (CsA) or FK506 is a cornerstone of immunosuppressive therapies. Here we found that calcineurin was recruited to the T cell antigen receptor (TCR) signaling complex, where it reversed inhibitory phosphorylation of the tyrosine kinase Lck on Ser59 (Lck(S59)). Loss of calcineurin activity impaired phosphorylation of Tyr493 of the tyrosine kinase ZAP-70 (ZAP-70(Y493)), as well as some downstream pathways in a manner consistent with signaling in cells expressing Lck(S59A) (Lck that cannot be phosphorylated) or Lck(S59E) (a phosphomimetic mutant). Notably, CsA inhibited integrin-LFA-1-dependent and NFAT-independent adhesion of T cells to the intercellular adhesion molecule ICAM-1, with little effect on cells expressing mutant Lck. These results provide new understanding of how widely used immunosuppressive drugs interfere with essential processes in the immune response.

  6. Destruction of solid tumors by immune cells

    Science.gov (United States)

    López, Álvaro G.; Seoane, Jesús M.; Sanjuán, Miguel A. F.

    2017-03-01

    The fractional cell kill is a mathematical expression describing the rate at which a certain population of cells is reduced to a fraction of itself. In order to investigate the fractional cell kill that governs the rate at which a solid tumor is lysed by a cell population of cytotoxic CD8+ T cells (CTLs), we present several in silico simulations and mathematical analyses. When the CTLs eradicate efficiently the tumor cells, the models predict a correlation between the morphology of the tumors and the rate at which they are lysed. However, when the effectiveness of the immune cells is decreased, the mathematical function fails to reproduce the process of lysis. This limit is thoroughly discussed and a new fractional cell kill is proposed.

  7. Bone marrow-derived cells are recruited by the melanoma tumor with endothelial cells contributing to tumor vasculature.

    Science.gov (United States)

    Bonfim-Silva, R; Souza, L E B; Melo, F U F; Oliveira, V C; Magalhães, D A R; Oliveira, H F; Covas, D T; Fontes, A M

    2017-01-01

    Tumor expansion is dependent on neovascularization, a process that requires sustained new vessel formation. Although the critical role of angiogenesis by endothelial sprouting in this process, controversy still prevails on whether angiogenesis involving bone marrow-derived endothelial cells, does contribute to this process. This study aims to evaluate the recruitment of bone marrow-derived cells by the melanoma tumor, including endothelial cells, and if they contribute to angiogenesis. A chimeric mouse model of GFP bone marrow was used to induce melanoma tumors derived from murine B16-F10 cell line. These tumors were evaluated for the presence of myeloid cells (CD11b), T lymphocytes (CD3, CD4 and CD8) and endothelial cells (VEGFR2 and CD31) derived from bone marrow. Mice transplanted with GFP+ cells showed significant bone marrow chimerism (90.9 ± 0.87 %) when compared to the GFP transgenic mice (90.66 ± 2.1 %, p = 0.83) demonstrating successful engraftment of donor bone marrow stem/progenitor cells. Analysis of the murine melanoma tumor showed the presence of donor cells in the tumors (3.5 ± 1.7 %) and interestingly, these cells represent endothelial cells (CD31+ cells; 11.5 ± 6.85 %) and myeloid cells (CD11b+ cells; 80 ± 21 %), but also tumor-infiltrating lymphocytes (CD8+ T cells, 13.31 ± 0.2 %; CD4+ T-cells, 2.1 ± 1.2 %). Examination of the tumor endothelium by confocal microscopy suggests the presence of donor CD31+/GFP+ cells in the wall of some blood vessels. This study demonstrates that bone marrow-derived cells are recruited by the murine melanoma tumor, with myeloid cells and CD4 and CD8 T lymphocytes migrating as antitumor immune response, and endothelial cells participating of the tumor blood vessels formation.

  8. Bombyx mori and Aedes aegypti form multi-functional immune complexes that integrate pattern recognition, melanization, coagulants, and hemocyte recruitment

    Science.gov (United States)

    Phillips, Dennis R.

    2017-01-01

    The innate immune system of insects responds to wounding and pathogens by mobilizing multiple pathways that provide both systemic and localized protection. Key localized responses in hemolymph include melanization, coagulation, and hemocyte encapsulation, which synergistically seal wounds and envelop and destroy pathogens. To be effective, these pathways require a targeted deposition of their components to provide protection without compromising the host. Extensive research has identified a large number of the effectors that comprise these responses, but questions remain regarding their post-translational processing, function, and targeting. Here, we used mass spectrometry to demonstrate the integration of pathogen recognition proteins, coagulants, and melanization components into stable, high-mass, multi-functional Immune Complexes (ICs) in Bombyx mori and Aedes aegypti. Essential proteins common to both include phenoloxidases, apolipophorins, serine protease homologs, and a serine protease that promotes hemocyte recruitment through cytokine activation. Pattern recognition proteins included C-type Lectins in B. mori, while A. aegypti contained a protein homologous to Plasmodium-resistant LRIM1 from Anopheles gambiae. We also found that the B. mori IC is stabilized by extensive transglutaminase-catalyzed cross-linking of multiple components. The melanization inhibitor Egf1.0, from the parasitoid wasp Microplitis demolitor, blocked inclusion of specific components into the IC and also inhibited transglutaminase activity. Our results show how coagulants, melanization components, and hemocytes can be recruited to a wound surface or pathogen, provide insight into the mechanism by which a parasitoid evades this immune response, and suggest that insects as diverse as Lepidoptera and Diptera utilize similar defensive mechanisms. PMID:28199361

  9. Bombyx mori and Aedes aegypti form multi-functional immune complexes that integrate pattern recognition, melanization, coagulants, and hemocyte recruitment.

    Science.gov (United States)

    Phillips, Dennis R; Clark, Kevin D

    2017-01-01

    The innate immune system of insects responds to wounding and pathogens by mobilizing multiple pathways that provide both systemic and localized protection. Key localized responses in hemolymph include melanization, coagulation, and hemocyte encapsulation, which synergistically seal wounds and envelop and destroy pathogens. To be effective, these pathways require a targeted deposition of their components to provide protection without compromising the host. Extensive research has identified a large number of the effectors that comprise these responses, but questions remain regarding their post-translational processing, function, and targeting. Here, we used mass spectrometry to demonstrate the integration of pathogen recognition proteins, coagulants, and melanization components into stable, high-mass, multi-functional Immune Complexes (ICs) in Bombyx mori and Aedes aegypti. Essential proteins common to both include phenoloxidases, apolipophorins, serine protease homologs, and a serine protease that promotes hemocyte recruitment through cytokine activation. Pattern recognition proteins included C-type Lectins in B. mori, while A. aegypti contained a protein homologous to Plasmodium-resistant LRIM1 from Anopheles gambiae. We also found that the B. mori IC is stabilized by extensive transglutaminase-catalyzed cross-linking of multiple components. The melanization inhibitor Egf1.0, from the parasitoid wasp Microplitis demolitor, blocked inclusion of specific components into the IC and also inhibited transglutaminase activity. Our results show how coagulants, melanization components, and hemocytes can be recruited to a wound surface or pathogen, provide insight into the mechanism by which a parasitoid evades this immune response, and suggest that insects as diverse as Lepidoptera and Diptera utilize similar defensive mechanisms.

  10. Multichannel fluorescence spinning disk microscopy reveals early endogenous CD4 T cell recruitment in contact sensitivity via complement.

    Science.gov (United States)

    Norman, M Ursula; Hulliger, Sara; Colarusso, Pina; Kubes, Paul

    2008-01-01

    Contact sensitivity (CS) is one of the primary in vivo models of T cell-mediated inflammation. The presence of CS-initiating CD4 T lymphocytes at the time of challenge is essential for transfer and full development of the late phase CS inflammatory response. From this observation investigators have speculated that early recruitment of CD4 T cells to the site of challenge must occur. Moreover, there must be rapid synthesis/release and disappearance of an important mediator during the first hours after hapten challenge. Using spinning disk confocal microscopy, we observed the very early effector events of the immune response. Simultaneous, real-time visualization of predominant neutrophil and extremely rare CD4 T cell trafficking in the challenged skin vasculature was noted (one rolling CD4 T cell for every 10-18 rolling and adherent neutrophils). We demonstrate that neutrophil adhesion during the early CS response was reduced in C5a receptor-deficient (C5aR-/-) mice or leukotriene B4 receptor antagonist-treated mice, whereas CD4 T cell recruitment was only inhibited in C5aR-/- mice. In line with these observations, leukocyte infiltration and the associated tissue damage were significantly reduced in C5aR-/- mice but not in leukotriene B4 receptor antagonist-treated wild-type mice 24 h after challenge. C5a receptor expression on T cells and not on tissue resident cells was important for the development of a CS response. Thus, by using spinning disk confocal microscopy we visualized the early events of an adaptive immune response and identified the rare but essential recruitment of CD4 T cells via the complement pathway.

  11. TLR3-induced activation of mast cells modulates CD8+ T-cell recruitment.

    Science.gov (United States)

    Orinska, Zane; Bulanova, Elena; Budagian, Vadim; Metz, Martin; Maurer, Marcus; Bulfone-Paus, Silvia

    2005-08-01

    Mast cells play an important role in host defense against various pathogens, but their role in viral infection has not been clarified in detail. dsRNA, synthesized by various types of viruses and mimicked by polyinosinic-polycytidylic acid (poly(I:C)) is recognized by Toll-like receptor 3 (TLR3). In this study, we demonstrate that poly(I:C) injection in vivo potently stimulates peritoneal mast cells to up-regulate a number of different costimulatory molecules. Therefore, we examined the expression and the functional significance of TLR3 activation in mast cells. Mast cells express TLR3 on the cell surface and intracellularly. After stimulation of mast cells with poly(I:C) and Newcastle disease virus (NDV), TLR3 is phosphorylated and the expression of key antiviral response cytokines (interferon beta, ISG15) and chemokines (IP10, RANTES) is upregulated. Interestingly, mast cells activated via TLR3-poly(I:C) potently stimulate CD8+ T-cell recruitment. Indeed, mast-cell-deficient mice (KitW/KitW-v) given an intraperitoneal injection of poly(I:C) show a decreased CD8+ T-cell recruitment, whereas granulocytes normally migrate to the peritoneal cavity. Mast-cell reconstitution of KitW/KitW-v mice normalizes the CD8+ T-cell influx. Thus, mast cells stimulated through engagement of TLR3 are potent regulators of CD8+ T-cell activities in vitro and in vivo.

  12. Immunological Signatures after Bordetella pertussis Infection Demonstrate Importance of Pulmonary Innate Immune Cells

    Science.gov (United States)

    Brummelman, Jolanda; van der Maas, Larissa; Tilstra, Wichard; Pennings, Jeroen L. A.; Han, Wanda G. H.; van Els, Cécile A. C. M.; van Riet, Elly; Kersten, Gideon F. A.; Metz, Bernard

    2016-01-01

    Effective immunity against Bordetella pertussis is currently under discussion following the stacking evidence of pertussis resurgence in the vaccinated population. Natural immunity is more effective than vaccine-induced immunity indicating that knowledge on infection-induced responses may contribute to improve vaccination strategies. We applied a systems biology approach comprising microarray, flow cytometry and multiplex immunoassays to unravel the molecular and cellular signatures in unprotected mice and protected mice with infection-induced immunity, around a B. pertussis challenge. Pre-existing systemic memory Th1/Th17 cells, memory B-cells, and mucosal IgA specific for Ptx, Vag8, Fim2/3 were detected in the protected mice 56 days after an experimental infection. In addition, pre-existing high activity and reactivation of pulmonary innate cells such as alveolar macrophages, M-cells and goblet cells was detected. The pro-inflammatory responses in the lungs and serum, and neutrophil recruitment in the spleen upon an infectious challenge of unprotected mice were absent in protected mice. Instead, fast pulmonary immune responses in protected mice led to efficient bacterial clearance and harbored potential new gene markers that contribute to immunity against B. pertussis. These responses comprised of innate makers, such as Clca3, Retlna, Glycam1, Gp2, and Umod, next to adaptive markers, such as CCR6+ B-cells, CCR6+ Th17 cells and CXCR6+ T-cells as demonstrated by transcriptome analysis. In conclusion, besides effective Th1/Th17 and mucosal IgA responses, the primary infection-induced immunity benefits from activation of pulmonary resident innate immune cells, achieved by local pathogen-recognition. These molecular signatures of primary infection-induced immunity provided potential markers to improve vaccine-induced immunity against B. pertussis. PMID:27711188

  13. Comparison of dendritic cell-mediated immune responses among canine malignant cells.

    Science.gov (United States)

    Tamura, Kyoichi; Arai, Hiroyoshi; Ueno, Emi; Saito, Chie; Yagihara, Hiroko; Isotani, Mayu; Ono, Kenichiro; Washizu, Tsukimi; Bonkobara, Makoto

    2007-09-01

    Dendritic cell (DC) vaccination is one of the most attractive immunotherapies for malignancies in dogs. To examine the differences in DC-mediated immune responses from different types of malignancies in dogs, we vaccinated dogs using autologous DCs pulsed with keyhole limpet hemocyanin (KLH) and cell lysate prepared from squamous cell carcinoma SCC2/88 (SCC-KLH-DC), histiocytic sarcoma CHS-5 (CHS-KLH-DC), or B cell leukemia GL-1 (GL-KLH-DC) in vitro. In vivo inductions of immune responses against these tumor cells were compared by the delayed-type hypersensitivity (DTH) skin test. The DTH response against SCC2/88 cells were observed in dogs vaccinated with autologous SCC-KLH-DC, while the response was undetectable against CHS-5 and GL-1 cells in dogs vaccinated with autologous CHS-KLH-DC and GL-KLH-DC. Skin biopsies taken from DTH challenge sites were then examined for immunohistochemistry, and recruitment of CD8 and CD4 T cells was detected at the site where SCC2/88 cells were inoculated in dogs vaccinated with SCC-KLH-DC. By contrast, neither CD8 nor CD4 T cell infiltration was found at the DTH challenge site in the dogs vaccinated with CHS-KLH-DC or GL-KLH-DC. These findings may reflect that the efficacy of immune induction by DC vaccination varies among tumor types and that immune responses could be inducible in squamous cell carcinoma. Our results encouraged further investigation of therapeutic vaccination for dogs with advanced squamous cell carcinoma in clinical trials.

  14. Live-cell imaging to measure BAX recruitment kinetics to mitochondria during apoptosis.

    Science.gov (United States)

    Maes, Margaret E; Schlamp, Cassandra L; Nickells, Robert W

    2017-01-01

    The pro-apoptotic BCL2 gene family member, BAX, plays a pivotal role in the intrinsic apoptotic pathway. Under cellular stress, BAX recruitment to the mitochondria occurs when activated BAX forms dimers, then oligomers, to initiate mitochondria outer membrane permeabilization (MOMP), a process critical for apoptotic progression. The activation and recruitment of BAX to form oligomers has been studied for two decades using fusion proteins with a fluorescent reporter attached in-frame to the BAX N-terminus. We applied high-speed live cell imaging to monitor the recruitment of BAX fusion proteins in dying cells. Data from time-lapse imaging was validated against the activity of endogenous BAX in cells, and analyzed using sigmoid mathematical functions to obtain detail of the kinetic parameters of the recruitment process at individual mitochondrial foci. BAX fusion proteins behave like endogenous BAX during apoptosis. Kinetic studies show that fusion protein recruitment is also minimally affected in cells lacking endogenous BAK or BAX genes, but that the kinetics are moderately, but significantly, different with different fluorescent tags in the fusion constructs. In experiments testing BAX recruitment in 3 different cell lines, our results show that regardless of cell type, once activated, BAX recruitment initiates simultaneously within a cell, but exhibits varying rates of recruitment at individual mitochondrial foci. Very early during BAX recruitment, pro-apoptotic molecules are released in the process of MOMP, but different molecules are released at different times and rates relative to the time of BAX recruitment initiation. These results provide a method for BAX kinetic analysis in living cells and yield greater detail of multiple characteristics of BAX-induced MOMP in living cells that were initially observed in cell free studies.

  15. Tumor's other immune targets: dendritic cells.

    Science.gov (United States)

    Esche, C; Lokshin, A; Shurin, G V; Gastman, B R; Rabinowich, H; Watkins, S C; Lotze, M T; Shurin, M R

    1999-08-01

    The induction of apoptosis in T cells is one of several mechanisms by which tumors escape immune recognition. We have investigated whether tumors induce apoptosis in dendritic cells (DC) by co-culture of murine or human DC with different tumor cell lines for 4-48 h. Analysis of DC morphological features, JAM assay, TUNEL, caspase-3-like and transglutaminase activity, Annexin V binding, and DNA fragmentation assays revealed a time- and dose-dependent induction of apoptosis in DC by tumor-derived factors. This finding is both effector and target specific. The mechanism of tumor-induced DC apoptosis involved regulation of Bcl-2 and Bax expression. Double staining of both murine and human tumor tissues confirmed that tumor-associated DC undergo apoptotic death in vivo. DC isolated from tumor tissue showed significantly higher levels of apoptosis as determined by TUNEL assay when compared with DC isolated from spleen. These findings demonstrate that tumors induce apoptosis in DC and suggest a new mechanism of tumor escape from immune recognition. DC protection from apoptosis will lead to improvement of DC-based immunotherapies for cancer and other immune diseases.

  16. Single-cell transcriptome analysis of fish immune cells provides insight into the evolution of vertebrate immune cell types

    Science.gov (United States)

    Ferreira, Lauren; Macaulay, Iain C.; Stubbington, Michael J.T.

    2017-01-01

    The immune system of vertebrate species consists of many different cell types that have distinct functional roles and are subject to different evolutionary pressures. Here, we first analyzed conservation of genes specific for all major immune cell types in human and mouse. Our results revealed higher gene turnover and faster evolution of trans-membrane proteins in NK cells compared with other immune cell types, and especially T cells, but similar conservation of nuclear and cytoplasmic protein coding genes. To validate these findings in a distant vertebrate species, we used single-cell RNA sequencing of lck:GFP cells in zebrafish and obtained the first transcriptome of specific immune cell types in a nonmammalian species. Unsupervised clustering and single-cell TCR locus reconstruction identified three cell populations, T cells, a novel type of NK-like cells, and a smaller population of myeloid-like cells. Differential expression analysis uncovered new immune-cell–specific genes, including novel immunoglobulin-like receptors, and neofunctionalization of recently duplicated paralogs. Evolutionary analyses confirmed the higher gene turnover of trans-membrane proteins in NK cells compared with T cells in fish species, suggesting that this is a general property of immune cell types across all vertebrates. PMID:28087841

  17. Interferon regulatory factor 8-deficiency determines massive neutrophil recruitment but T cell defect in fast growing granulomas during tuberculosis.

    Directory of Open Access Journals (Sweden)

    Stefano Rocca

    Full Text Available Following Mycobacterium tuberculosis (Mtb infection, immune cell recruitment in lungs is pivotal in establishing protective immunity through granuloma formation and neogenesis of lymphoid structures (LS. Interferon regulatory factor-8 (IRF-8 plays an important role in host defense against Mtb, although the mechanisms driving anti-mycobacterial immunity remain unclear. In this study, IRF-8 deficient mice (IRF-8⁻/⁻ were aerogenously infected with a low-dose Mtb Erdman virulent strain and the course of infection was compared with that induced in wild-type (WT-B6 counterparts. Tuberculosis (TB progression was examined in both groups using pathological, microbiological and immunological parameters. Following Mtb exposure, the bacterial load in lungs and spleens progressed comparably in the two groups for two weeks, after which IRF-8⁻/⁻ mice developed a fatal acute TB whereas in WT-B6 the disease reached a chronic stage. In lungs of IRF-8⁻/⁻, uncontrolled growth of pulmonary granulomas and impaired development of LS were observed, associated with unbalanced homeostatic chemokines, progressive loss of infiltrating T lymphocytes and massive prevalence of neutrophils at late infection stages. Our data define IRF-8 as an essential factor for the maintenance of proper immune cell recruitment in granulomas and LS required to restrain Mtb infection. Moreover, IRF-8⁻/⁻ mice, relying on a common human and mouse genetic mutation linked to susceptibility/severity of mycobacterial diseases, represent a valuable model of acute TB for comparative studies with chronically-infected congenic WT-B6 for dissecting protective and pathological immune reactions.

  18. Interferon regulatory factor 8-deficiency determines massive neutrophil recruitment but T cell defect in fast growing granulomas during tuberculosis.

    Science.gov (United States)

    Rocca, Stefano; Schiavoni, Giovanna; Sali, Michela; Anfossi, Antonio Giovanni; Abalsamo, Laura; Palucci, Ivana; Mattei, Fabrizio; Sanchez, Massimo; Giagu, Anna; Antuofermo, Elisabetta; Fadda, Giovanni; Belardelli, Filippo; Delogu, Giovanni; Gabriele, Lucia

    2013-01-01

    Following Mycobacterium tuberculosis (Mtb) infection, immune cell recruitment in lungs is pivotal in establishing protective immunity through granuloma formation and neogenesis of lymphoid structures (LS). Interferon regulatory factor-8 (IRF-8) plays an important role in host defense against Mtb, although the mechanisms driving anti-mycobacterial immunity remain unclear. In this study, IRF-8 deficient mice (IRF-8⁻/⁻) were aerogenously infected with a low-dose Mtb Erdman virulent strain and the course of infection was compared with that induced in wild-type (WT-B6) counterparts. Tuberculosis (TB) progression was examined in both groups using pathological, microbiological and immunological parameters. Following Mtb exposure, the bacterial load in lungs and spleens progressed comparably in the two groups for two weeks, after which IRF-8⁻/⁻ mice developed a fatal acute TB whereas in WT-B6 the disease reached a chronic stage. In lungs of IRF-8⁻/⁻, uncontrolled growth of pulmonary granulomas and impaired development of LS were observed, associated with unbalanced homeostatic chemokines, progressive loss of infiltrating T lymphocytes and massive prevalence of neutrophils at late infection stages. Our data define IRF-8 as an essential factor for the maintenance of proper immune cell recruitment in granulomas and LS required to restrain Mtb infection. Moreover, IRF-8⁻/⁻ mice, relying on a common human and mouse genetic mutation linked to susceptibility/severity of mycobacterial diseases, represent a valuable model of acute TB for comparative studies with chronically-infected congenic WT-B6 for dissecting protective and pathological immune reactions.

  19. Are Platelets Cells? And if Yes, Are They Immune Cells?

    Directory of Open Access Journals (Sweden)

    Fabrice eCOGNASSE

    2015-02-01

    Full Text Available Small fragments circulating in the blood were formally identified by the end of the 19th century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the 20th century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such however, they were acknowledged as immunizing (to specific HPA and HLA markers: the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as the 1930s, platelets entered the arsenal of medicines; were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an immune cell? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages. The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of

  20. Immune and Inflammatory Cell Composition of Human Lung Cancer Stroma

    National Research Council Canada - National Science Library

    Banat, G-Andre; Tretyn, Aleksandra; Pullamsetti, Soni Savai; Wilhelm, Jochen; Weigert, Andreas; Olesch, Catherine; Ebel, Katharina; Stiewe, Thorsten; Grimminger, Friedrich; Seeger, Werner; Fink, Ludger; Savai, Rajkumar

    2015-01-01

    .... We comprehensively assessed the number of stromal cells, especially immune/inflammatory cells, in lung cancer and evaluated their infiltration in cancers of different stages, types and metastatic...

  1. NKp46 clusters at the immune synapse and regulates NK cell polarization

    Directory of Open Access Journals (Sweden)

    Uzi eHadad

    2015-09-01

    Full Text Available Natural killer cells play an important role in first-line defense against tumor and virus-infected cells. The activity of NK cells is tightly regulated by a repertoire of cell-surface expressed inhibitory and activating receptors. NKp46 is a major NK cell activating receptor that is involved in the elimination of target cells. NK cells form different types of synapses that result in distinct functional outcomes: cytotoxic, inhibitory, and regulatory. Recent studies revealed that complex integration of NK receptor signaling controls cytoskeletal rearrangement and other immune synapse-related events. However the distinct nature by which NKp46 participates in NK immunological synapse formation and function remains unknown. In this study we determined that NKp46 forms microclusters structures at the immune synapse between NK cells and target cells. Over-expression of human NKp46 is correlated with increased accumulation of F-actin mesh at the immune synapse. Concordantly, knock-down of NKp46 in primary human NK cells decreased recruitment of F-actin to the synapse. Live cell imaging experiments showed a linear correlation between NKp46 expression and lytic granules polarization to the immune synapse. Taken together, our data suggest that NKp46 signaling directly regulates the NK lytic immune synapse from early formation to late function.

  2. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1998-01-01

    The specific aims of the project were: (1) Application of the NASA bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC). (2) Compare the frequency and function of DC in normal donors and immunocompromised cancer patients. (3) Analyze the effectiveness of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in a murine model of experimental fungal disease. Our investigations have provided new insight into DC immunobiology and have led to the development of methodology to evaluate DC in blood of normal donors and patients. Information gained from these studies has broadened our understanding of possible mechanisms involved in the immune dysfunction of space travelers and earth-bound cancer patients, and could contribute to the design of novel therapies to restore/preserve immunity in these individuals. Several new avenues of investigation were also revealed. The results of studies completed during Round 2 are summarized.

  3. MCP-1 promotes mural cell recruitment during angiogenesis in the aortic ring model.

    Science.gov (United States)

    Aplin, Alfred C; Fogel, Eric; Nicosia, Roberto F

    2010-09-01

    Rings of rat or mouse aorta embedded in collagen gels produce angiogenic outgrowths in response to the injury of the dissection procedure. Aortic outgrowths are composed of branching endothelial tubes and surrounding mural cells. Mural cells emerge following endothelial sprouting and gradually increase during the maturation of the neovessels. Treatment of aortic cultures with angiopoietin-1 (Ang-1), an angiogenic factor implicated in vascular maturation and remodeling, stimulates the mural cell recruitment process. Ang-1 induces expression of many cytokines and chemokines including monocyte chemotactic protein-1 (MCP-1). Inhibition of p38 MAP kinase, a signaling molecule required for mural cell recruitment, blocks Ang1-induced MCP-1 expression. Recombinant MCP-1 dose-dependently increases mural cell number while an anti-MCP-1 blocking antibody reduces it. In addition, antibody mediated neutralization of MCP-1 abrogates the stimulatory effect of Ang-1 on mural cell recruitment. Aortic rings from genetically modified mice deficient in MCP-1 or its receptor CCR2 have fewer mural cells than controls. MCP-1 deficiency also impairs the mural cell recruitment activity of Ang-1. Our studies indicate that spontaneous and Ang1-induced mural cell recruitment in the aortic ring of model of angiogenesis are in part mediated by MCP-1. These results implicate MCP-1 as one of the mediators of mural cell recruitment in the aortic ring model, and suggest that chemokine pathways may contribute to the assembly of the vessel wall during the angiogenesis response to injury.

  4. Vaginal immunization to elicit primary T-cell activation and dissemination.

    Directory of Open Access Journals (Sweden)

    Elena Pettini

    Full Text Available Primary T-cell activation at mucosal sites is of utmost importance for the development of vaccination strategies. T-cell priming after vaginal immunization, with ovalbumin and CpG oligodeoxynucleotide adjuvant as model vaccine formulation, was studied in vivo in hormone-synchronized mice and compared to the one induced by the nasal route. Twenty-four hours after both vaginal or nasal immunization, antigen-loaded dendritic cells were detected within the respective draining lymph nodes. Vaginal immunization elicited a strong recruitment of antigen-specific CD4(+ T cells into draining lymph nodes that was more rapid than the one observed following nasal immunization. T-cell clonal expansion was first detected in iliac lymph nodes, draining the genital tract, and proliferated T cells disseminated towards distal lymph nodes and spleen similarly to what observed following nasal immunization. T cells were indeed activated by the antigen encounter and acquired homing molecules essential to disseminate towards distal lymphoid organs as confirmed by the modulation of CD45RB, CD69, CD44 and CD62L marker expression. A multi-type Galton Watson branching process, previously used for in vitro analysis of T-cell proliferation, was applied to model in vivo CFSE proliferation data in draining lymph nodes 57 hours following immunization, in order to calculate the probabilistic decision of a cell to enter in division, rest in quiescence or migrate/die. The modelling analysis indicated that the probability of a cell to proliferate was higher following vaginal than nasal immunization. All together these data show that vaginal immunization, despite the absence of an organized mucosal associated inductive site in the genital tract, is very efficient in priming antigen-specific CD4(+ T cells and inducing their dissemination from draining lymph nodes towards distal lymphoid organs.

  5. Recruitment of dendritic cells to the cerebrospinal fluid in bacterial neuroinfections.

    Science.gov (United States)

    Pashenkov, Mikhail; Teleshova, Natalia; Kouwenhoven, Mathilde; Smirnova, Tatiana; Jin, Ya Ping; Kostulas, Vasilios; Huang, Yu Min; Pinegin, Boris; Boiko, Alexey; Link, Hans

    2002-01-01

    Dendritic cells (DC) accumulate in the CNS during inflammation and may contribute to local immune responses. Two DC subsets present in human cerebrospinal fluid (CSF) are probably recruited from myeloid (CD11c(+)CD123(dim)) and plasmacytoid (CD11c(-)CD123(high)) blood DC. In bacterial meningitis and especially in Lyme meningoencephalitis, numbers of myeloid and plasmacytoid DC in CSF were increased, compared to non-inflammatory neurological diseases, and correlated with chemotactic activity of CSF for immature monocyte-derived DC (moDC). Multiple DC chemoattractants, including macrophage inflammatory protein (MIP)-1beta, monocyte chemotactic protein (MCP)-1, MCP-3, RANTES and stromal cell-derived factor (SDF)-1alpha were elevated in CSF in these two neuroinfections. Chemotaxis of immature moDC induced by these CSFs could be partially inhibited by mAbs against CXCR4, the receptor for SDF-1alpha, and CD88, the receptor for C5a. SDF-1alpha present in CSF also chemoattracted mature moDC, which in vivo could correspond to a diminished migration of antigen-bearing DC from the CSF to secondary lymphoid organs. Regulation of DC trafficking to and from the CSF may represent a mechanism of controlling the CNS inflammation.

  6. Neutrophil-derived CCL3 is essential for the rapid recruitment of dendritic cells to the site of Leishmania major inoculation in resistant mice.

    Directory of Open Access Journals (Sweden)

    Mélanie Charmoy

    2010-02-01

    Full Text Available Neutrophils are rapidly and massively recruited to sites of microbial infection, where they can influence the recruitment of dendritic cells. Here, we have analyzed the role of neutrophil released chemokines in the early recruitment of dendritic cells (DCs in an experimental model of Leishmania major infection. We show in vitro, as well as during infection, that the parasite induced the expression of CCL3 selectively in neutrophils from L. major resistant mice. Neutrophil-secreted CCL3 was critical in chemotaxis of immature DCs, an effect lost upon CCL3 neutralisation. Depletion of neutrophils prior to infection, as well as pharmacological or genetic inhibition of CCL3, resulted in a significant decrease in DC recruitment at the site of parasite inoculation. Decreased DC recruitment in CCL3(-/- mice was corrected by the transfer of wild type neutrophils at the time of infection. The early release of CCL3 by neutrophils was further shown to have a transient impact on the development of a protective immune response. Altogether, we identified a novel role for neutrophil-secreted CCL3 in the first wave of DC recruitment to the site of infection with L. major, suggesting that the selective release of neutrophil-secreted chemokines may regulate the development of immune response to pathogens.

  7. Estimation of immune cell densities in immune cell conglomerates: an approach for high-throughput quantification.

    Directory of Open Access Journals (Sweden)

    Niels Halama

    Full Text Available BACKGROUND: Determining the correct number of positive immune cells in immunohistological sections of colorectal cancer and other tumor entities is emerging as an important clinical predictor and therapy selector for an individual patient. This task is usually obstructed by cell conglomerates of various sizes. We here show that at least in colorectal cancer the inclusion of immune cell conglomerates is indispensable for estimating reliable patient cell counts. Integrating virtual microscopy and image processing principally allows the high-throughput evaluation of complete tissue slides. METHODOLOGY/PRINCIPAL FINDINGS: For such large-scale systems we demonstrate a robust quantitative image processing algorithm for the reproducible quantification of cell conglomerates on CD3 positive T cells in colorectal cancer. While isolated cells (28 to 80 microm(2 are counted directly, the number of cells contained in a conglomerate is estimated by dividing the area of the conglomerate in thin tissues sections (< or =6 microm by the median area covered by an isolated T cell which we determined as 58 microm(2. We applied our algorithm to large numbers of CD3 positive T cell conglomerates and compared the results to cell counts obtained manually by two independent observers. While especially for high cell counts, the manual counting showed a deviation of up to 400 cells/mm(2 (41% variation, algorithm-determined T cell numbers generally lay in between the manually observed cell numbers but with perfect reproducibility. CONCLUSION: In summary, we recommend our approach as an objective and robust strategy for quantifying immune cell densities in immunohistological sections which can be directly implemented into automated full slide image processing systems.

  8. Identification of skin immune cells in non-human primates.

    Science.gov (United States)

    Adam, Lucille; Rosenbaum, Pierre; Cosma, Antonio; Le Grand, Roger; Martinon, Frédéric

    2015-11-01

    The skin is a valuable target for vaccine delivery because it contains many immune cell populations, notably antigen presenting cells. Skin immune cells have been extensively described in mice and humans but not in non-human primates, which are pertinent models for immunological research in vaccination. The aim of this work was to describe immune cell populations in the epidermis, dermis and skin draining lymph nodes in cynomolgus macaques by a single 12-parameter flow cytometry protocol. Given that skin cells share several markers, we defined a gating strategy to identify accurately immune cells and to limit contamination of one immune cell population by another. The epidermis contained CD1a(+)CD1c(-) Langerhans cells (LCs), CD3(+) T cells and putative NK cells. The dermis contained CD1a(+)CD1c(-) cells, which were similar to LCs, CD1a(+)CD1c(+) dermal dendritic cells (DDCs), CD163(high)CD11b(+) resident macrophages, CD3(+) T cells and putative NK cells. The skin also contained CD66(+) polymorphonuclear cells in some animals. Thus, immune cell populations in the macaque are similar to those in humans despite some differences in phenotype. In skin draining lymph nodes, we identified migratory LCs, CD1a(+)CD1c(+) DDCs and macrophages. The simultaneous identification of these different immune cells with one panel of markers avoids the use of large amounts of precious sample and may improve the understanding of immune mechanisms in the skin after treatment or vaccination.

  9. Mast Cell and Immune Inhibitory Receptors

    Institute of Scientific and Technical Information of China (English)

    LixinLi; ZhengbinYao

    2004-01-01

    Modulation by balancing activating and inhibitory receptors constitutes an important mechanism for regulating immune responses. Cells that are activated following ligation of receptors bearing immunoreceptor tyrosine-based activation motifs (ITAMs) can be negatively regulated by other receptors bearing immunoreceptor tyrosine-based inhibition motifs (ITIMs). Human mast cells (MCs) are the major effector cells of type I hypersensitivity and important participants in a number of disease processes. Antigen-mediated aggregation of IgE bound to its high-affinity receptor on MCs initiates a complex series of biochemical events leading to MC activation. With great detailed description and analysis of several inhibitory receptors on human MCs, a central paradigm of negative regulation of human MC activation by these receptors has emerged. Cellular & Molecular Immunology. 2004;1(6):408-415.

  10. Regulation of Immune Cells by Eicosanoid Receptors

    Directory of Open Access Journals (Sweden)

    Nancy D. Kim

    2007-01-01

    Full Text Available Eicosanoids are potent, bioactive, lipid mediators that regulate important components of the immune response, including defense against infection, ischemia, and injury, as well as instigating and perpetuating autoimmune and inflammatory conditions. Although these lipids have numerous effects on diverse cell types and organs, a greater understanding of their specific effects on key players of the immune system has been gained in recent years through the characterization of individual eicosanoid receptors, the identification and development of specific receptor agonists and inhibitors, and the generation of mice genetically deficient in various eicosanoid receptors. In this review, we will focus on the receptors for prostaglandin D2, DP1 and DP2/CRTH2; the receptors for leukotriene B4, BLT1 and BLT2; and the receptors for the cysteinyl leukotrienes, CysLT1 and CysLT2, by examining their specific effects on leukocyte subpopulations, and how they may act in concert towards the development of immune and inflammatory responses.

  11. New insights into the dual recruitment of IgA+ B cells in the developing mammary gland.

    Science.gov (United States)

    Bourges, Dorothée; Meurens, François; Berri, Mustapha; Chevaleyre, Claire; Zanello, Galliano; Levast, Benoît; Melo, Sandrine; Gerdts, Volker; Salmon, Henri

    2008-07-01

    In monogastric mammals, transfer of passive immunity via milk and colostrum plays an important role in protecting the neonate against mucosal infections. Here we analyzed the hypothesis that during gestation/lactation IgA+ plasmablasts leave the intestinal and respiratory surfaces towards the mammary gland (MG). We compared the recruitment of lymphocytes expressing homing receptors alpha4beta1 and alpha4beta7 to expression of their vascular counter-receptors, VCAM-1 and MAdCAM-1. Furthermore, the expression of the chemokines responsible for the recruitment of IgA+ plasmablasts was analyzed. Data confirmed that expressions of CCL28 and MAdCAM-1 in the MG increased during pregnancy and alpha4beta1+ and alpha4beta7+/IgA+ cell recruitment in lactation correlated with increase of CCL28 expression. Interestingly, VCAM-1 expression was found in small blood vessels of the lactating porcine MG, while in mice VCAM-1 was expressed in large blood vessels within the MG. Thus, our results indicate that the recruitment of IgA+ plasmablasts to MG is mediated by VCAM-1/alpha4beta1 and MAdCAM-1/alpha4beta7 in conjunction with CCL28/CCR10. They support the existence of a functional link between entero- and upper respiratory surfaces and MG, thereby, conferring protection against aero-digestive pathogens in the newborn.

  12. The Shc family protein adaptor, Rai, negatively regulates T cell antigen receptor signaling by inhibiting ZAP-70 recruitment and activation.

    Directory of Open Access Journals (Sweden)

    Micol Ferro

    Full Text Available Rai/ShcC is a member of the Shc family of protein adaptors expressed with the highest abundance in the central nervous system, where it exerts a protective function by coupling neurotrophic receptors to the PI3K/Akt survival pathway. Rai is also expressed, albeit at lower levels, in other cell types, including T and B lymphocytes. We have previously reported that in these cells Rai attenuates antigen receptor signaling, thereby impairing not only cell proliferation but also, opposite to neurons, cell survival. Here we have addressed the mechanism underlying the inhibitory activity of Rai on TCR signaling. We show that Rai interferes with the TCR signaling cascade one of the earliest steps--recruitment of the initiating kinase ZAP-70 to the phosphorylated subunit of the TCR/CD3 complex, which results in a generalized dampening of the downstream signaling events. The inhibitory activity of Rai is associated to its inducible recruitment to phosphorylated CD3, which occurs in the physiological signaling context of the immune synapse. Rai is moreover found as a pre-assembled complex with ZAP-70 and also constitutively interacts with the regulatory p85 subunit of PI3K, similar to neuronal cells, notwithstanding the opposite biological outcome, i.e. impairment of PI-3K/Akt activation. The data highlight the ability of Rai to establish interactions with the TCR and key signaling mediators which, either directly (e.g. by inhibiting ZAP-70 recruitment to the TCR or sequestering ZAP-70/PI3K in the cytosol or indirectly (e.g. by promoting the recruitment of effectors responsible for signal extinction prevent full triggering of the TCR signaling cascade.

  13. The Reticular Cell Network : A Robust Backbone for Immune Responses

    NARCIS (Netherlands)

    Textor, Johannes; Mandl, Judith N; de Boer, Rob J

    2016-01-01

    Lymph nodes are meeting points for circulating immune cells. A network of reticular cells that ensheathe a mesh of collagen fibers crisscrosses the tissue in each lymph node. This reticular cell network distributes key molecules and provides a structure for immune cells to move around on. During inf

  14. Regeneration and Cell Recruitment in an Improved Heterotopic Auxiliary Partial Liver Transplantation Model in the Rat.

    Science.gov (United States)

    Ono, Yoshihiro; Pérez-Gutiérrez, Angelica; Yovchev, Mladen I; Matsubara, Kentaro; Yokota, Shinichiro; Guzman-Lepe, Jorge; Handa, Kan; Collin de l'Hortet, Alexandra; Thomson, Angus W; Geller, David A; Yagi, Hiroshi; Oertel, Michael; Soto-Gutierrez, Alejandro

    2017-01-01

    Auxiliary partial liver transplantation (APLT) in humans is a therapeutic modality used especially to treat liver failure in children or congenital metabolic disease. Animal models of APLT have helped to explore therapeutic options. Though many groups have suggested improvements, standardizing the surgical procedure has been challenging. Additionally, the question of whether graft livers are reconstituted by recipient-derived cells after transplantation has been controversial. The aim of this study was to improve experimental APLT in rats and to assess cell recruitment in the liver grafts. To inhibit recipient liver regeneration and to promote graft regeneration, we treated recipients with retrorsine and added arterial anastomosis. Using green fluorescence protein transgenic rats as recipients, we examined liver resident cell recruitment within graft livers by immunofluorescence costaining. In the improved APLT model, we achieved well-regenerated grafts that could maintain regeneration for at least 4 weeks. Regarding the cell recruitment, there was no evidence of recipient-derived hepatocyte, cholangiocyte, or hepatic stellate cell recruitment into the graft. Macrophages/monocytes, however, were consistently recruited into the graft and increased over time, which might be related to inflammatory responses. Very few endothelial cells showed colocalization of markers. We have successfully established an improved rat APLT model with arterial anastomosis as a standard technique. Using this model, we have characterized cell recruitment into the regenerating grafts.

  15. Deciphering dendritic cell heterogenity in immunity

    Directory of Open Access Journals (Sweden)

    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  16. Smooth muscle cell recruitment to lymphatic vessels requires PDGFB and impacts vessel size but not identity.

    Science.gov (United States)

    Wang, Yixin; Jin, Yi; Mäe, Maarja Andaloussi; Zhang, Yang; Ortsäter, Henrik; Betsholtz, Christer; Mäkinen, Taija; Jakobsson, Lars

    2017-08-29

    Tissue-fluid drains through blind-ended lymphatic capillaries, via smooth muscle cell (SMC)-covered collecting vessels into venous circulation. Both defective SMC recruitment to collecting vessels and ectopic recruitment to lymphatic capillaries are thought to contribute to vessel failure, leading to lymphedema. However, mechanisms controlling lymphatic SMC recruitment and their role in vessel maturation are unknown. Here we demonstrate that platelet-derived growth factor B (PDGFB) regulates lymphatic SMC recruitment in multiple vascular beds. PDGFB is selectively expressed by lymphatic endothelial cells (LECs) of collecting vessels. LEC-specific deletion of Pdgfb prevented SMC recruitment causing dilation and failure of pulsatile contraction of collecting vessels. However, vessel remodelling and identity were unaffected. Unexpectedly, PDGFB overexpression in LECs did not induce SMC recruitment to capillaries. This was explained by the demonstrated requirement of PDGFB extracellular matrix (ECM) retention for lymphatic SMC recruitment, and low presence of PDGFB-binding ECM components around lymphatic capillaries. These results demonstrate a requirement of LEC-autonomous PDGFB expression and retention for SMC recruitment to lymphatic vessels and suggest an ECM-controlled checkpoint preventing SMC investment of capillaries, which is a common feature in lymphedematous skin. © 2017. Published by The Company of Biologists Ltd.

  17. Role of SRC-like adaptor protein (SLAP) in immune and malignant cell signaling.

    Science.gov (United States)

    Kazi, Julhash U; Kabir, Nuzhat N; Rönnstrand, Lars

    2015-07-01

    SRC-like adaptor protein (SLAP) is an adaptor protein structurally similar to the SRC family protein kinases. Like SRC, SLAP contains an SH3 domain followed by an SH2 domain but the kinase domain has been replaced by a unique C-terminal region. SLAP is expressed in a variety of cell types. Current studies suggest that it regulates signaling of various cell surface receptors including the B cell receptor, the T cell receptor, cytokine receptors and receptor tyrosine kinases which are important regulator of immune and cancer cell signaling. SLAP targets receptors, or its associated components, by recruiting the ubiquitin machinery and thereby destabilizing signaling. SLAP directs receptors to ubiquitination-mediated degradation and controls receptors turnover as well as signaling. Thus, SLAP appears to be an important component in regulating signal transduction required for immune and malignant cells.

  18. Group B Streptococcus Induces Neutrophil Recruitment to Gestational Tissues and Elaboration of Extracellular Traps and Nutritional Immunity

    Science.gov (United States)

    Kothary, Vishesh; Doster, Ryan S.; Rogers, Lisa M.; Kirk, Leslie A.; Boyd, Kelli L.; Romano-Keeler, Joann; Haley, Kathryn P.; Manning, Shannon D.; Aronoff, David M.; Gaddy, Jennifer A.

    2017-01-01

    Streptococcus agalactiae, or Group B Streptococcus (GBS), is a gram-positive bacterial pathogen associated with infection during pregnancy and is a major cause of morbidity and mortality in neonates. Infection of the extraplacental membranes surrounding the developing fetus, a condition known as chorioamnionitis, is characterized histopathologically by profound infiltration of polymorphonuclear cells (PMNs, neutrophils) and greatly increases the risk for preterm labor, stillbirth, or neonatal GBS infection. The advent of animal models of chorioamnionitis provides a powerful tool to study host-pathogen relationships in vivo and ex vivo. The purpose of this study was to evaluate the innate immune response elicited by GBS and evaluate how antimicrobial strategies elaborated by these innate immune cells affect bacteria. Our work using a mouse model of GBS ascending vaginal infection during pregnancy reveals that clinically isolated GBS has the capacity to invade reproductive tissues and elicit host immune responses including infiltration of PMNs within the choriodecidua and placenta during infection, mirroring the human condition. Upon interacting with GBS, murine neutrophils elaborate DNA-containing extracellular traps, which immobilize GBS and are studded with antimicrobial molecules including lactoferrin. Exposure of GBS to holo- or apo-forms of lactoferrin reveals that the iron-sequestration activity of lactoferrin represses GBS growth and viability in a dose-dependent manner. Together, these data indicate that the mouse model of ascending infection is a useful tool to recapitulate human models of GBS infection during pregnancy. Furthermore, this work reveals that neutrophil extracellular traps ensnare GBS and repress bacterial growth via deposition of antimicrobial molecules, which drive nutritional immunity via metal sequestration strategies. PMID:28217556

  19. [Understanding of immune system by visualization of spatiotemporal regulation of immune cells in the entire body].

    Science.gov (United States)

    Tomura, Michio

    2013-01-01

    Immune system is high-dimensional integrated system distributed in the whole body. Many kinds of, total 10(11) of immune cells are regulated by receiving appropriate signals in appropriate places. We have been attempting to understand immune system by revealing spatiotemporal regulation of immune cells at the whole body level by "Visualization of immune response in vivo". Photoconvertible protein, "Kaede"-Tg mice allowed us to monitor cell-replacement and cell-movement in the whole body by marking cells with color of Kaede from green to red with exposure to violet light. It is applicable to small cell number populations in both lymphoid organs and also peripheral tissues under both normal and pathophysiological conditions. By using this system, we have demonstrated novel findings that "Naive CD4(+) T cell recirculation is an active process that they recirculate through lymphoid organs to seek limited niche for interacting with endogenous antigens and upregulate their function." and "Activated regulatory T cells emigrating from cutaneous immune response is responsible for termination of immune reponse." I will introduce these new tools of us and would like to discuss what is needed to understand immune system in the entire body.

  20. The Evolving Roles of Memory Immune Cells in Transplantation.

    Science.gov (United States)

    Chen, Wenhao; Ghobrial, Rafik M; Li, Xian C

    2015-10-01

    Memory cells are the products of immune responses but also exert significant impact on subsequent immunity and immune tolerance, thus placing them in a unique position in transplant research. Memory cells are heterogeneous, including not only memory T cells but also memory B cells and innate memory cells. Memory cells are a critical component of protective immunity against invading pathogens, especially in immunosuppressed patients, but they also mediate graft loss and tolerance resistance. Recent studies suggest that some memory cells unexpectedly act as regulatory cells, promoting rather than hindering transplant survival. This functional diversity makes therapeutic targeting of memory cells a challenging task in transplantation. In this article, we highlight recent advances in our understanding of memory cells, focusing on diversity of memory cells and mechanisms involved in their induction and functions. We also provide a broad overview on the challenges and opportunities in targeting memory cells in the induction of transplant tolerance.

  1. Nuclear factor of activated T cells regulates neutrophil recruitment, systemic inflammation, and T-cell dysfunction in abdominal sepsis.

    Science.gov (United States)

    Zhang, Su; Luo, Lingtao; Wang, Yongzhi; Gomez, Maria F; Thorlacius, Henrik

    2014-08-01

    The signaling mechanisms regulating neutrophil recruitment, systemic inflammation, and T-cell dysfunction in polymicrobial sepsis are not clear. This study explored the potential involvement of the calcium/calcineurin-dependent transcription factor, nuclear factor of activated T cells (NFAT), in abdominal sepsis. Cecal ligation and puncture (CLP) triggered NFAT-dependent transcriptional activity in the lung, spleen, liver, and aorta in NFAT-luciferase reporter mice. Treatment with the NFAT inhibitor A-285222 prior to CLP completely prevented sepsis-induced NFAT activation in all these organs. Inhibition of NFAT activity reduced sepsis-induced formation of CXCL1, CXCL2, and CXCL5 chemokines and edema as well as neutrophil infiltration in the lung. Notably, NFAT inhibition efficiently reduced the CLP-evoked increases in HMBG1, interleukin 6 (IL-6), and CXCL5 levels in plasma. Moreover, administration of A-285222 restored sepsis-induced T-cell dysfunction, as evidenced by markedly decreased apoptosis and restored proliferative capacity of CD4 T cells. Along these lines, treatment with A-285222 restored gamma interferon (IFN-γ) and IL-4 levels in the spleen, which were markedly reduced in septic mice. CLP-induced formation of regulatory T cells (CD4(+) CD25(+) Foxp3(+)) in the spleen was also abolished in A-285222-treated animals. All together, these novel findings suggest that NFAT is a powerful regulator of pathological inflammation and T-cell immune dysfunction in abdominal sepsis. Thus, our data suggest that NFAT signaling might be a useful target to protect against respiratory failure and immunosuppression in patients with sepsis.

  2. Immune modulation by dendritic-cell-based cancer vaccines

    Indian Academy of Sciences (India)

    CHAITANYA KUMAR; SAKSHI KOHLI; POONAMALLE PARTHASARATHY BAPSY; ASHOK KUMAR VAID; MINISH JAIN; VENKATA SATHYA SURESH ATTILI; BANDANA SHARAN

    2017-03-01

    The interplay between host immunity and tumour cells has opened the possibility of targeting tumour cells bymodulation of the human immune system. Cancer immunotherapy involves the treatment of a tumour by utilizing therecombinant human immune system components to target the pro-tumour microenvironment or by revitalizing theimmune system with the ability to kill tumour cells by priming the immune cells with tumour antigens. In this review,current immunotherapy approaches to cancer with special focus on dendritic cell (DC)-based cancer vaccines arediscussed. Some of the DC-based vaccines under clinical trials for various cancer types are highlighted. Establishingtumour immunity involves a plethora of immune components and pathways; hence, combining chemotherapy,radiation therapy and various arms of immunotherapy, after analysing the benefits of individual therapeutic agents,might be beneficial to the patient.

  3. Synthetic Immunology: Hacking Immune Cells to Expand Their Therapeutic Capabilities.

    Science.gov (United States)

    Roybal, Kole T; Lim, Wendell A

    2017-04-26

    The ability of immune cells to survey tissues and sense pathologic insults and deviations makes them a unique platform for interfacing with the body and disease. With the rapid advancement of synthetic biology, we can now engineer and equip immune cells with new sensors and controllable therapeutic response programs to sense and treat diseases that our natural immune system cannot normally handle. Here we review the current state of engineered immune cell therapeutics and their unique capabilities compared to small molecules and biologics. We then discuss how engineered immune cells are being designed to combat cancer, focusing on how new synthetic biology tools are providing potential ways to overcome the major roadblocks for treatment. Finally, we give a long-term vision for the use of synthetic biology to engineer immune cells as a general sensor-response platform to precisely detect disease, to remodel disease microenvironments, and to treat a potentially wide range of challenging diseases.

  4. Cesarean section imprints cord blood immune cell distributions

    DEFF Research Database (Denmark)

    Thysen, Anna Hammerich; Larsen, Jeppe Madura; Rasmussen, Mette Annelie;

    2014-01-01

    Immune programming in early life may affect the risk of developing immune-related diseases later in life. Children born by cesarean section seem to be at higher risk of asthma, allergic rhinitis, and type-1 diabetes. We hypothesized that delivery by cesarean section may affect immune maturation...... in newborns. The objective of the study was to profile innate and adaptive immune cell subsets in cord blood of children born by cesarean section or natural birth....

  5. In vivo protein synthesis determinations in human immune cells

    OpenAIRE

    Januszkiewicz, Anna

    2005-01-01

    Intact immune responses are essential for defeating severe infections in individual patients. Insufficient function of the immune system contributes to a poor prognosis in these patients, in particular the ICU patients. Nevertheless, the immune system function is not easily monitored and evaluated. The ongoing metabolic activity of immune competent cells is reflected by their in vivo protein synthesis rate. The aim of this thesis was to apply in vivo protein synthesis measur...

  6. Pathogenic T-cell recruitment into the airway in human disease.

    Science.gov (United States)

    Medoff, Benjamin D; Thomas, Seddon Y; Banerji, Aleena; Wain, John C; Zhang, Hui; Lilly, Craig M; Ginns, Leo C; Luster, Andrew D

    2005-12-01

    Effector T cells significantly contribute to inflammatory diseases. These cells are recruited into tissue, where they orchestrate an inflammatory response that can either protect against infection or sometimes stimulate human disease. The recruitment of T cells into tissue from the blood and lymphoid compartments is an active process controlled by chemokines and the chemokine receptors expressed on distinct effector T-cell subsets. Thus, the chemokines secreted in the tissue will determine the specific types of T lymphocyte recruited into that tissue based on the chemokine receptors expressed on these cells. It follows that the chemokine receptor profile on T cells isolated from the lungs of patients with inflammatory pulmonary disease will define the subtype of pathogenic T lymphocytes mediating the disease process and will identify the mechanisms that recruit these cells into the lung. This article reviews data from both human and animal studies that define the chemokine receptors involved in the recruitment of T lymphocytes into the lung in various inflammatory pulmonary diseases, including asthma, obliterative bronchiolitis, sarcoidosis, and chronic eosinophilic pneumonia. We then speculate on the potential role of these chemokine receptors in the pathogenesis of these disorders and potential novel therapeutic approaches suggested by these data.

  7. Monocyte recruitment to the dermis and differentiation to dendritic cells increases the targets for dengue virus replication.

    Science.gov (United States)

    Schmid, Michael A; Harris, Eva

    2014-12-01

    Dengue virus (DENV) causes the most prevalent arthropod-borne viral disease in humans. Although Aedes mosquitoes transmit DENV when probing for blood in the skin, no information exists on DENV infection and immune response in the dermis, where the blood vessels are found. DENV suppresses the interferon response, replicates, and causes disease in humans but not wild-type mice. Here, we used mice lacking the interferon-α/β receptor (Ifnar(-/-)), which had normal cell populations in the skin and were susceptible to intradermal DENV infection, to investigate the dynamics of early DENV infection of immune cells in the skin. CD103(+) classical dendritic cells (cDCs), Ly6C(-) CD11b(+) cDCs, and macrophages in the steady-state dermis were initial targets of DENV infection 12-24 hours post-inoculation but then decreased in frequency. We demonstrated recruitment of adoptively-transferred Ly6C(high) monocytes from wild-type and Ifnar(-/-) origin to the DENV-infected dermis and differentiation to Ly6C(+) CD11b(+) monocyte-derived DCs (moDCs), which became DENV-infected after 48 hours, and were then the major targets for virus replication. Ly6C(high) monocytes that entered the DENV-infected dermis expressed chemokine receptor CCR2, likely mediating recruitment. Further, we show that ∼ 100-fold more hematopoietic cells in the dermis were DENV-infected compared to Langerhans cells in the epidermis. Overall, these results identify the dermis as the main site of early DENV replication and show that DENV infection in the skin occurs in two waves: initial infection of resident cDCs and macrophages, followed by infection of monocytes and moDCs that are recruited to the dermis. Our study reveals a novel viral strategy of exploiting monocyte recruitment to increase the number of targets for infection at the site of invasion in the skin and highlights the skin as a potential site for therapeutic action or intradermal vaccination.

  8. Monocyte recruitment to the dermis and differentiation to dendritic cells increases the targets for dengue virus replication.

    Directory of Open Access Journals (Sweden)

    Michael A Schmid

    2014-12-01

    Full Text Available Dengue virus (DENV causes the most prevalent arthropod-borne viral disease in humans. Although Aedes mosquitoes transmit DENV when probing for blood in the skin, no information exists on DENV infection and immune response in the dermis, where the blood vessels are found. DENV suppresses the interferon response, replicates, and causes disease in humans but not wild-type mice. Here, we used mice lacking the interferon-α/β receptor (Ifnar(-/-, which had normal cell populations in the skin and were susceptible to intradermal DENV infection, to investigate the dynamics of early DENV infection of immune cells in the skin. CD103(+ classical dendritic cells (cDCs, Ly6C(- CD11b(+ cDCs, and macrophages in the steady-state dermis were initial targets of DENV infection 12-24 hours post-inoculation but then decreased in frequency. We demonstrated recruitment of adoptively-transferred Ly6C(high monocytes from wild-type and Ifnar(-/- origin to the DENV-infected dermis and differentiation to Ly6C(+ CD11b(+ monocyte-derived DCs (moDCs, which became DENV-infected after 48 hours, and were then the major targets for virus replication. Ly6C(high monocytes that entered the DENV-infected dermis expressed chemokine receptor CCR2, likely mediating recruitment. Further, we show that ∼ 100-fold more hematopoietic cells in the dermis were DENV-infected compared to Langerhans cells in the epidermis. Overall, these results identify the dermis as the main site of early DENV replication and show that DENV infection in the skin occurs in two waves: initial infection of resident cDCs and macrophages, followed by infection of monocytes and moDCs that are recruited to the dermis. Our study reveals a novel viral strategy of exploiting monocyte recruitment to increase the number of targets for infection at the site of invasion in the skin and highlights the skin as a potential site for therapeutic action or intradermal vaccination.

  9. The Distinctive Sensitivity to Microgravity of Immune Cell Subpopulations

    Science.gov (United States)

    Chen, Hui; Luo, Haiying; Liu, Jing; Wang, Peng; Dong, Dandan; Shang, Peng; Zhao, Yong

    2015-11-01

    Immune dysfunction in astronauts is well documented after spaceflights. Microgravity is one of the key factors directly suppressing the function of immune system. However, it is unclear which subpopulations of immune cells including innate and adaptive immune cells are more sensitive to microgravity We herein investigated the direct effects of modeled microgravity (MMg) on different immune cells in vitro. Mouse splenocytes, thymocytes and bone marrow cells were exposed to MMg for 16 hrs. The survival and the phenotypes of different subsets of immune cells including CD4+T cells, CD8+T cells, CD4+Foxp3+ regulatory T cells (Treg), B cells, monocytes/macrophages, dendritic cells (DCs), natural killer cells (NK) were determined by flow cytometry. After splenocytes were cultured under MMg for 16h, the cell frequency and total numbers of monocytes, macrophages and CD4+Foxp3+T cells were significantly decreased more than 70 %. MMg significantly decreased the cell numbers of CD8+ T cells, B cells and neutrophils in splenocytes. The cell numbers of CD4+T cells and NK cells were unchanged significantly when splenocytes were cultured under MMg compared with controls. However, MMg significantly increased the ratio of mature neutrophils to immature neutrophils in bone marrow and the cell number of DCs in splenocytes. Based on the cell survival ability, monocytes, macrophages and CD4+Foxp3+Treg cells are most sensitive to microgravity; CD4+T cells and NK cells are resistant to microgravity; CD8+T cells and neutrophils are impacted by short term microgravity exposure. Microgravity promoted the maturation of neutrophils and development of DCs in vitro. The present studies offered new insights on the direct effects of MMg on the survival and homeostasis of immune cell subsets.

  10. Reduced inflammatory cell recruitment and tissue damage in spinal cord injury by acellular spinal cord scaffold seeded with mesenchymal stem cells.

    Science.gov (United States)

    Wang, Yu-Hai; Chen, Jian; Zhou, Jing; Nong, Feng; Lv, Jin-Han; Liu, Jia

    2017-01-01

    Therapy using acellular spinal cord (ASC) scaffolds seeded with bone marrow stromal cells (BMSCs) has previously been shown to restore function of the damaged spinal cord and improve functional recovery in a rat model of acute hemisected spinal cord injury (SCI). The aim of the present study was to determine whether BMSCs and ASC scaffolds promote the functional recovery of the damaged spinal cord in a rat SCI model through regulation of apoptosis and immune responses. Whether this strategy regulates secondary inflammation, which is characterized by the infiltration of immune cells and inflammatory mediators to the lesion site, in SCI repair was investigated. Basso, Beattie, and Bresnahan scores revealed that treatment with BMSCs seeded into an ASC scaffold led to a significant improvement in motor function recovery compared with treatment with an ASC scaffold alone or untreated controls at 2 and 8 weeks after surgery (Pscaffold significantly decreased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, as compared with the ASC scaffold only and control groups. These results suggested that the use of BMSCs decreased the apoptosis of neural cells and thereby limited tissue damage at the lesion site. Notably, the use of BMSCs with an ASC scaffold also decreased the recruitment of macrophages (microglia; Pscaffold only groups. BMSCs regulated inflammatory cell recruitment to promote functional recovery. However, there was no significant difference in IgM-positive expression among the three groups (P>0.05). The results of this study demonstrated that BMSCs seeded into ASC scaffolds for repair of spinal cord hemisection defects promoted functional recovery through the early regulation of inflammatory cell recruitment with inhibition of apoptosis and secondary inflammation.

  11. The immune system GTPase GIMAP6 interacts with the Atg8 homologue GABARAPL2 and is recruited to autophagosomes.

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    John C Pascall

    Full Text Available The GIMAPs (GTPases of the immunity-associated proteins are a family of small GTPases expressed prominently in the immune systems of mammals and other vertebrates. In mammals, studies of mutant or genetically-modified rodents have indicated important roles for the GIMAP GTPases in the development and survival of lymphocytes. No clear picture has yet emerged, however, of the molecular mechanisms by which they perform their function(s. Using biotin tag-affinity purification we identified a major, and highly specific, interaction between the human cytosolic family member GIMAP6 and GABARAPL2, one of the mammalian homologues of the yeast autophagy protein Atg8. Chemical cross-linking studies performed on Jurkat T cells, which express both GIMAP6 and GABARAPL2 endogenously, indicated that the two proteins in these cells readily associate with one another in the cytosol under normal conditions. The GIMAP6-GABARAPL2 interaction was disrupted by deletion of the last 10 amino acids of GIMAP6. The N-terminal region of GIMAP6, however, which includes a putative Atg8-family interacting motif, was not required. Over-expression of GIMAP6 resulted in increased levels of endogenous GABARAPL2 in cells. After culture of cells in starvation medium, GIMAP6 was found to localise in punctate structures with both GABARAPL2 and the autophagosomal marker MAP1LC3B, indicating that GIMAP6 re-locates to autophagosomes on starvation. Consistent with this finding, we have demonstrated that starvation of Jurkat T cells results in the degradation of GIMAP6. Whilst these findings raise the possibility that the GIMAPs play roles in the regulation of autophagy, we have been unable to demonstrate an effect of GIMAP6 over-expression on autophagic flux.

  12. PTPROt maintains T cell immunity in the microenvironment of hepatocellular carcinoma.

    Science.gov (United States)

    Hou, Jiajie; Deng, Lei; Zhuo, Han; Lin, Zhe; Chen, Yun; Jiang, Runqiu; Chen, Dianyu; Zhang, Xudong; Huang, Xingxu; Sun, Beicheng

    2015-08-01

    Intratumoral T cells play a central role in anti-tumor immunity, and the balance between T effector cells (Teff) and regulatory T cells (Treg) affects the prognosis of cancer patients. However, educated by tumor microenvironment, T cells frequently fail in their responsibility. In this study, we aimed to investigate the role of truncated isoform of protein tyrosine phosphatase receptor-type O (PTPROt) in T cell-mediated anti-tumor immunity. We recruited 70 hepatocellular carcinoma (HCC) patients and 30 healthy volunteers for clinical investigation, and analyzed cellular tumor immunity by using ptpro(-/-) C57BL/6 mice and NOD/SCID mice. PTPROt expression was significantly downregulated in human HCC-infiltrating T cells due to the hypoxia microenvironment; PTPROt expression highly correlated with the intratumoral Teff/Treg ratio and clinicopathologic characteristics. Moreover, PTPROt deficiency attenuated T cell-mediated anti-tumor immunity and remarkably promoted mouse HCC growth. Mechanistically, deletion of PTPROt decreased Teff quantity and quality through phosphorylation of lymphocyte-specific tyrosine kinase, but increased Treg differentiation through phosphorylation of signal transducer and activator of transcription 5. In support of the Teff/Treg homeostasis, PTPROt serves as an important tumor suppressor in HCC microenvironment. © The Author (2015). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  13. Intestinal dendritic cells in the regulation of mucosal immunity

    DEFF Research Database (Denmark)

    Bekiaris, Vasileios; Persson, Emma K.; Agace, William Winston

    2014-01-01

    immune cells within the mucosa must suitably respond to maintain intestinal integrity, while also providing the ability to mount effective immune responses to potential pathogens. Dendritic cells (DCs) are sentinel immune cells that play a central role in the initiation and differentiation of adaptive...... immune responses. In the intestinal mucosa, DCs are located diffusely throughout the intestinal lamina propria, within gut-associated lymphoid tissues, including Peyer's patches and smaller lymphoid aggregates, as well as in intestinal-draining lymph nodes, including mesenteric lymph nodes....... The recognition that dietary nutrients and microbial communities in the intestine influence both mucosal and systemic immune cell development and function as well as immune-mediated disease has led to an explosion of literature in mucosal immunology in recent years and a growing interest in the functionality...

  14. Polymicrobial sepsis impairs bystander recruitment of effector cells to infected skin despite optimal sensing and alarming function of skin resident memory CD8 T cells

    Science.gov (United States)

    Shan, Qiang; Xue, Hai-Hui; Harty, John T.

    2017-01-01

    Sepsis is a systemic infection that enhances host vulnerability to secondary infections normally controlled by T cells. Using CLP sepsis model, we observed that sepsis induces apoptosis of circulating memory CD8 T-cells (TCIRCM) and diminishes their effector functions, leading to impaired CD8 T-cell mediated protection to systemic pathogen re-infection. In the context of localized re-infections, tissue resident memory CD8 T-cells (TRM) provide robust protection in a variety of infectious models. TRM rapidly ‘sense’ infection in non-lymphoid tissues and ‘alarm’ the host by enhancing immune cell recruitment to the site of the infection to accelerate pathogen clearance. Here, we show that compared to pathogen-specific TCIRCM, sepsis does not invoke significant numerical decline of Vaccinia virus induced skin-TRM keeping their effector functions (e.g., Ag-dependent IFN-γ production) intact. IFN-γ-mediated recruitment of immune cells to the site of localized infection was, however, reduced in CLP hosts despite TRM maintaining their ‘sensing and alarming’ functions. The capacity of memory CD8 T-cells in the septic environment to respond to inflammatory cues and arrive to the site of secondary infection/antigen exposure remained normal suggesting T-cell-extrinsic factors contributed to the observed lesion. Mechanistically, we showed that IFN-γ produced rapidly during sepsis-induced cytokine storm leads to reduced IFN-γR1 expression on vascular endothelium. As a consequence, decreased expression of adhesion molecules and/or chemokines (VCAM1 and CXCL9) on skin endothelial cells in response to TRM-derived IFN-γ was observed, leading to sub-optimal bystander-recruitment of effector cells and increased susceptibility to pathogen re-encounter. Importantly, as visualized by intravital 2-photon microscopy, exogenous administration of CXCL9/10 was sufficient to correct sepsis-induced impairments in recruitment of effector cells at the localized site of TRM

  15. Polymicrobial sepsis impairs bystander recruitment of effector cells to infected skin despite optimal sensing and alarming function of skin resident memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Derek B Danahy

    2017-09-01

    Full Text Available Sepsis is a systemic infection that enhances host vulnerability to secondary infections normally controlled by T cells. Using CLP sepsis model, we observed that sepsis induces apoptosis of circulating memory CD8 T-cells (TCIRCM and diminishes their effector functions, leading to impaired CD8 T-cell mediated protection to systemic pathogen re-infection. In the context of localized re-infections, tissue resident memory CD8 T-cells (TRM provide robust protection in a variety of infectious models. TRM rapidly 'sense' infection in non-lymphoid tissues and 'alarm' the host by enhancing immune cell recruitment to the site of the infection to accelerate pathogen clearance. Here, we show that compared to pathogen-specific TCIRCM, sepsis does not invoke significant numerical decline of Vaccinia virus induced skin-TRM keeping their effector functions (e.g., Ag-dependent IFN-γ production intact. IFN-γ-mediated recruitment of immune cells to the site of localized infection was, however, reduced in CLP hosts despite TRM maintaining their 'sensing and alarming' functions. The capacity of memory CD8 T-cells in the septic environment to respond to inflammatory cues and arrive to the site of secondary infection/antigen exposure remained normal suggesting T-cell-extrinsic factors contributed to the observed lesion. Mechanistically, we showed that IFN-γ produced rapidly during sepsis-induced cytokine storm leads to reduced IFN-γR1 expression on vascular endothelium. As a consequence, decreased expression of adhesion molecules and/or chemokines (VCAM1 and CXCL9 on skin endothelial cells in response to TRM-derived IFN-γ was observed, leading to sub-optimal bystander-recruitment of effector cells and increased susceptibility to pathogen re-encounter. Importantly, as visualized by intravital 2-photon microscopy, exogenous administration of CXCL9/10 was sufficient to correct sepsis-induced impairments in recruitment of effector cells at the localized site of TRM

  16. Programmed cell death in the plant immune system.

    Science.gov (United States)

    Coll, N S; Epple, P; Dangl, J L

    2011-08-01

    Cell death has a central role in innate immune responses in both plants and animals. Besides sharing striking convergences and similarities in the overall evolutionary organization of their innate immune systems, both plants and animals can respond to infection and pathogen recognition with programmed cell death. The fact that plant and animal pathogens have evolved strategies to subvert specific cell death modalities emphasizes the essential role of cell death during immune responses. The hypersensitive response (HR) cell death in plants displays morphological features, molecular architectures and mechanisms reminiscent of different inflammatory cell death types in animals (pyroptosis and necroptosis). In this review, we describe the molecular pathways leading to cell death during innate immune responses. Additionally, we present recently discovered caspase and caspase-like networks regulating cell death that have revealed fascinating analogies between cell death control across both kingdoms.

  17. Tricking the balance: NK cells in anti-cancer immunity.

    Science.gov (United States)

    Pahl, Jens; Cerwenka, Adelheid

    2017-01-01

    Natural Killer (NK) cells are classically considered innate immune effector cells involved in the first line of defense against infected and malignant cells. More recently, NK cells have emerged to acquire properties of adaptive immunity in response to certain viral infections such as expansion of specific NK cell subsets and long-lasting virus-specific responses to secondary challenges. NK cells distinguish healthy cells from abnormal cells by measuring the net input of activating and inhibitory signals perceived from target cells through NK cell surface receptors. Acquisition of activating ligands in combination with reduced expression of MHC class I molecules on virus-infected and cancer cells activates NK cell cytotoxicity and release of immunostimulatory cytokines like IFN-γ. In the cancer microenvironment however, NK cells become functionally impaired by inhibitory factors produced by immunosuppressive immune cells and cancer cells. Here we review recent progress on the role of NK cells in cancer immunity. We describe regulatory factors of the tumor microenvironment on NK cell function which determine cancer cell destruction or escape from immune recognition. Finally, recent strategies that focus on exploiting NK cell anti-cancer responses for immunotherapeutic approaches are outlined. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis.

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    Silvia Affò

    Full Text Available Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6-/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6-/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6-/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+ and mature dendritic (MHCII+CD11c+ cells recruitment. Clodronate depletion of macrophages in Ccr6-/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis.

  19. Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis.

    Science.gov (United States)

    Affò, Silvia; Rodrigo-Torres, Daniel; Blaya, Delia; Morales-Ibanez, Oriol; Coll, Mar; Millán, Cristina; Altamirano, José; Arroyo, Vicente; Caballería, Joan; Bataller, Ramón; Ginès, Pere; Sancho-Bru, Pau

    2015-01-01

    Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6-/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6-/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6-/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+) and mature dendritic (MHCII+CD11c+) cells recruitment. Clodronate depletion of macrophages in Ccr6-/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis.

  20. Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis

    Science.gov (United States)

    Blaya, Delia; Morales-Ibanez, Oriol; Coll, Mar; Millán, Cristina; Altamirano, José; Arroyo, Vicente; Caballería, Joan; Bataller, Ramón; Ginès, Pere; Sancho-Bru, Pau

    2015-01-01

    Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6-/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6-/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6-/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+) and mature dendritic (MHCII+CD11c+) cells recruitment. Clodronate depletion of macrophages in Ccr6-/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis. PMID:26691857

  1. Liver restores immune homeostasis after local inflammation despite the presence of autoreactive T cells.

    Directory of Open Access Journals (Sweden)

    Kathie Béland

    Full Text Available The liver must keep equilibrium between immune tolerance and immunity in order to protect itself from pathogens while maintaining tolerance to food antigens. An imbalance between these two states could result in an inflammatory liver disease. The aims of this study were to identify factors responsible for a break of tolerance and characterize the subsequent restoration of liver immune homeostasis. A pro-inflammatory environment was created in the liver by the co-administration of TLR ligands CpG and Poly(I:C in presence or absence of activated liver-specific autoreactive CD8(+ T cells. Regardless of autoreactive CD8(+ T cells, mice injected with CpG and Poly(I:C showed elevated serum ALT levels and a transient liver inflammation. Both CpG/Poly(I:C and autoreactive CD8(+T cells induced expression of TLR9 and INF-γ by the liver, and an up-regulation of homing and adhesion molecules CXCL9, CXCL10, CXCL16, ICAM-1 and VCAM-1. Transferred CFSE-labeled autoreactive CD8(+ T cells, in presence of TLR3 and 9 ligands, were recruited by the liver and spleen and proliferated. This population then contracted by apoptosis through intrinsic and extrinsic pathways. Up-regulation of FasL and PD-L1 in the liver was observed. In conclusion, TLR-mediated activation of the innate immune system results in a pro-inflammatory environment that promotes the recruitment of lymphocytes resulting in bystander hepatitis. Despite this pro-inflammatory environment, the presence of autoreactive CD8(+ T cells is not sufficient to sustain an autoimmune response against the liver and immune homeostasis is rapidly restored through the apoptosis of T cells.

  2. REST-mediated recruitment of polycomb repressor complexes in mammalian cells.

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    Nikolaj Dietrich

    Full Text Available Polycomb Repressive Complex (PRC 1 and PRC2 regulate genes involved in differentiation and development. However, the mechanism for how PRC1 and PRC2 are recruited to genes in mammalian cells is unclear. Here we present evidence for an interaction between the transcription factor REST, PRC1, and PRC2 and show that RNF2 and REST co-regulate a number of neuronal genes in human teratocarcinoma cells (NT2-D1. Using NT2-D1 cells as a model of neuronal differentiation, we furthermore showed that retinoic-acid stimulation led to displacement of PRC1 at REST binding sites, reduced H3K27Me3, and increased gene expression. Genome-wide analysis of Polycomb binding in Rest⁻/⁻ and Eed⁻/⁻ mouse embryonic stem (mES cells showed that Rest was required for PRC1 recruitment to a subset of Polycomb regulated neuronal genes. Furthermore, we found that PRC1 can be recruited to Rest binding sites independently of CpG islands and the H3K27Me3 mark. Surprisingly, PRC2 was frequently increased around Rest binding sites located in CpG-rich regions in the Rest⁻/⁻ mES cells, indicating a more complex interplay where Rest also can limit PRC2 recruitment. Therefore, we propose that Rest has context-dependent functions for PRC1- and PRC2- recruitment, which allows this transcription factor to act both as a recruiter of Polycomb as well as a limiting factor for PRC2 recruitment at CpG islands.

  3. Differential Protein Network Analysis of the Immune Cell Lineage

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    Trevor Clancy

    2014-01-01

    Full Text Available Recently, the Immunological Genome Project (ImmGen completed the first phase of the goal to understand the molecular circuitry underlying the immune cell lineage in mice. That milestone resulted in the creation of the most comprehensive collection of gene expression profiles in the immune cell lineage in any model organism of human disease. There is now a requisite to examine this resource using bioinformatics integration with other molecular information, with the aim of gaining deeper insights into the underlying processes that characterize this immune cell lineage. We present here a bioinformatics approach to study differential protein interaction mechanisms across the entire immune cell lineage, achieved using affinity propagation applied to a protein interaction network similarity matrix. We demonstrate that the integration of protein interaction networks with the most comprehensive database of gene expression profiles of the immune cells can be used to generate hypotheses into the underlying mechanisms governing the differentiation and the differential functional activity across the immune cell lineage. This approach may not only serve as a hypothesis engine to derive understanding of differentiation and mechanisms across the immune cell lineage, but also help identify possible immune lineage specific and common lineage mechanism in the cells protein networks.

  4. GC-rich sequence elements recruit PRC2 in mammalian ES cells.

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    Eric M Mendenhall

    2010-12-01

    Full Text Available Polycomb proteins are epigenetic regulators that localize to developmental loci in the early embryo where they mediate lineage-specific gene repression. In Drosophila, these repressors are recruited to sequence elements by DNA binding proteins associated with Polycomb repressive complex 2 (PRC2. However, the sequences that recruit PRC2 in mammalian cells have remained obscure. To address this, we integrated a series of engineered bacterial artificial chromosomes into embryonic stem (ES cells and examined their chromatin. We found that a 44 kb region corresponding to the Zfpm2 locus initiates de novo recruitment of PRC2. We then pinpointed a CpG island within this locus as both necessary and sufficient for PRC2 recruitment. Based on this causal demonstration and prior genomic analyses, we hypothesized that large GC-rich elements depleted of activating transcription factor motifs mediate PRC2 recruitment in mammals. We validated this model in two ways. First, we showed that a constitutively active CpG island is able to recruit PRC2 after excision of a cluster of activating motifs. Second, we showed that two 1 kb sequence intervals from the Escherichia coli genome with GC-contents comparable to a mammalian CpG island are both capable of recruiting PRC2 when integrated into the ES cell genome. Our findings demonstrate a causal role for GC-rich sequences in PRC2 recruitment and implicate a specific subset of CpG islands depleted of activating motifs as instrumental for the initial localization of this key regulator in mammalian genomes.

  5. Protection against HIV-disease progression: From immune activation to T-cell immunity

    NARCIS (Netherlands)

    Spits, H.B.

    2015-01-01

    HIV infection undermines the immune system by causing a gradual loss of CD4+ T cells. Eventually, the weakened immune system is no longer able to offer resistance to opportunistic infections and the HIV-infected individual will develop AIDS. Even after 30 years of intensive research on HIV, there is

  6. Human periodontal ligament cells facilitate leukocyte recruitment and are influenced in their immunomodulatory function by Th17 cytokine release.

    Science.gov (United States)

    Konermann, A; Beyer, M; Deschner, J; Allam, J P; Novak, N; Winter, J; Jepsen, S; Jäger, A

    2012-01-01

    The objective of this in vitro study was to examine the immunomodulatory impact of human periodontal ligament (PDL) cells on the nature and magnitude of the leukocyte infiltrate in periodontal inflammation, particularly with regard to Th17 cells. PDL cells were challenged with pro-inflammatory cytokines (IL-1ß, IL-17A, and IFN-γ) and analyzed for the expression of cytokines involved in periodontal immunoinflammatory processes (IL-6, MIP-3 alpha, IL-23A, TGFß1, IDO, and CD274). In order to further investigate a direct involvement of PDL cells in leukocyte function, co-culture experiments were conducted. The expression of the immunomodulatory cytokines studied was significantly increased under pro-inflammatory conditions in PDL cells. Although PDL cells did not stimulate leukocyte proliferation or Th17 differentiation, these cells induced the recruitment of leukocytes. The results of our study suggest that PDL cells might be involved in chronic inflammatory mechanisms in periodontal tissues and thus in the transition to an adaptive immune response in periodontitis.

  7. NKT cell networks in the regulation of tumor immunity

    Directory of Open Access Journals (Sweden)

    Faith C Robertson

    2014-10-01

    Full Text Available CD1d-restricted natural killer T (NKT cells lie at the interface between the innate and adaptive immune systems and are important mediators of immune responses and tumor immunosurveillance. These NKT cells uniquely recognize lipid antigens, and their rapid yet specific reactions influence both innate and adaptive immunity. In tumor immunity, two NKT subsets (type I and type II have contrasting roles in which they not only cross-regulate one another, but also impact innate immune cell populations, including natural killer, dendritic and myeloid lineage cells, as well as adaptive populations, especially CD8+ and CD4+ T cells. The extent to which NKT cells promote or suppress surrounding cells affects the host’s ability to prevent neoplasia and is consequently of great interest for therapeutic development. Data have shown the potential for therapeutic use of NKT cell agonists and synergy with immune response modifiers in both pre-clinical studies and preliminary clinical studies. However, there is room to improve treatment efficacy by further elucidating the biological mechanisms underlying NKT cell networks. Here, we discuss the progress made in understanding NKT cell networks, their consequent role in the regulation of tumor immunity, and the potential to exploit that knowledge in a clinical setting.

  8. The Dynamics of Interactions Among Immune and Glioblastoma Cells.

    Science.gov (United States)

    Eder, Katalin; Kalman, Bernadette

    2015-12-01

    Glioblastoma is the most common intracranial malignancy that constitutes about 50 % of all gliomas. Despite aggressive, multimodal therapy consisting of surgery, radiation, and chemotherapy, the outcome of patients with glioblastoma remains poor with 5-year survival rates of immune mediators may represent a critical contributor to this resistance. The tumor microenvironment contains innate and adaptive immune cells in addition to the cancer cells and their surrounding stroma. These various cells communicate with each other by means of direct cell-cell contact or by soluble factors including cytokines and chemokines, and act in autocrine and paracrine manners to modulate tumor growth. There are dynamic interactions among the local immune elements and the tumor cells, where primarily the protective immune cells attempt to overcome the malignant cells. However, by developing somatic mutations and epigenetic modifications, the glioblastoma tumor cells acquire the capability of counteracting the local immune responses, and even exploit the immune cells and products for their own growth benefits. In this review, we survey those immune mechanisms that likely contribute to glioblastoma pathogenesis and may serve as a basis for novel treatment strategies.

  9. Metabolic pathways in immune cell activation and quiescence.

    Science.gov (United States)

    Pearce, Erika L; Pearce, Edward J

    2013-04-18

    Studies of immune system metabolism ("immunometabolism") segregate along two paths. The first investigates the effects of immune cells on organs that regulate whole-body metabolism, such as adipose tissue and liver. The second explores the role of metabolic pathways within immune cells and how this regulates immune response outcome. Distinct metabolic pathways diverge and converge at many levels, and, therefore, cells face choices as to how to achieve their metabolic goals. There is interest in fully understanding how and why immune cells commit to particular metabolic fates and in elucidating the immunologic consequences of reaching a metabolic endpoint by one pathway versus another. This is particularly intriguing, given that metabolic commitment is influenced not only by substrate availability but also by signaling pathways elicited by metabolites. Thus, metabolic choices in cells enforce fate and function, and this area will be the subject of this review. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Exosomes and nanotubes: Control of immune cell communication.

    Science.gov (United States)

    McCoy-Simandle, Kessler; Hanna, Samer J; Cox, Dianne

    2016-02-01

    Cell-cell communication is critical to coordinate the activity and behavior of a multicellular organism. The cells of the immune system not only must communicate with similar cells, but also with many other cell types in the body. Therefore, the cells of the immune system have evolved multiple ways to communicate. Exosomes and tunneling nanotubes (TNTs) are two means of communication used by immune cells that contribute to immune functions. Exosomes are small membrane vesicles secreted by most cell types that can mediate intercellular communication and in the immune system they are proposed to play a role in antigen presentation and modulation of gene expression. TNTs are membranous structures that mediate direct cell-cell contact over several cell diameters in length (and possibly longer) and facilitate the interaction and/or the transfer of signals, material and other cellular organelles between connected cells. Recent studies have revealed additional, but sometimes conflicting, structural and functional features of both exosomes and TNTs. Despite the new and exciting information in exosome and TNT composition, origin and in vitro function, biologically significant functions are still being investigated and determined. In this review, we discuss the current field regarding exosomes and TNTs in immune cells providing evaluation and perspectives of the current literature.

  11. Aedes aegypti saliva alters leukocyte recruitment and cytokine signaling by antigen-presenting cells during West Nile virus infection.

    Directory of Open Access Journals (Sweden)

    Bradley S Schneider

    Full Text Available West Nile virus (WNV is transmitted during mosquito bloodfeeding. Consequently, the first vertebrate cells to contact WNV are cells in the skin, followed by those in the draining lymph node. Macrophages and dendritic cells are critical early responders in host defense against WNV infection, not just because of their role in orchestrating the immune response, but also because of their importance as sites of early peripheral viral replication. Antigen-presenting cell (APC signals have a profound effect on host antiviral responses and disease severity. During transmission, WNV is intimately associated with mosquito saliva. Due to the ability of mosquito saliva to affect inflammation and immune responses, and the importance of understanding early events in WNV infection, we investigated whether mosquito saliva alters APC signaling during arbovirus infection, and if alterations in cell recruitment occur when WNV infection is initiated with mosquito saliva. Accordingly, experiments were performed with cultured dendritic cells and macrophages, flow cytometry was used to characterize infiltrating cell types in the skin and lymph nodes during early infection, and real-time RT-PCR was employed to evaluate virus and cytokine levels. Our in vitro results suggest that mosquito saliva significantly decreases the expression of interferon-beta and inducible nitric oxide synthase in macrophages (by as much as 50 and 70%, respectively, whilst transiently enhancing interleukin-10 (IL-10 expression. In vivo results indicate that the predominate effect of mosquito feeding is to significantly reduce the recruitment of T cells, leading the inoculation site of mice exposed to WNV alone to have up to 2.8 fold more t cells as mice infected in the presence of mosquito saliva. These shifts in cell population are associated with significantly elevated IL-10 and WNV (up to 4.0 and 10 fold, respectively in the skin and draining lymph nodes. These results suggest that mosquito

  12. Tumor infiltrating immune cells in gliomas and meningiomas.

    Science.gov (United States)

    Domingues, Patrícia; González-Tablas, María; Otero, Álvaro; Pascual, Daniel; Miranda, David; Ruiz, Laura; Sousa, Pablo; Ciudad, Juana; Gonçalves, Jesús María; Lopes, María Celeste; Orfao, Alberto; Tabernero, María Dolores

    2016-03-01

    Tumor-infiltrating immune cells are part of a complex microenvironment that promotes and/or regulates tumor development and growth. Depending on the type of cells and their functional interactions, immune cells may play a key role in suppressing the tumor or in providing support for tumor growth, with relevant effects on patient behavior. In recent years, important advances have been achieved in the characterization of immune cell infiltrates in central nervous system (CNS) tumors, but their role in tumorigenesis and patient behavior still remain poorly understood. Overall, these studies have shown significant but variable levels of infiltration of CNS tumors by macrophage/microglial cells (TAM) and to a less extent also lymphocytes (particularly T-cells and NK cells, and less frequently also B-cells). Of note, TAM infiltrate gliomas at moderate numbers where they frequently show an immune suppressive phenotype and functional behavior; in contrast, infiltration by TAM may be very pronounced in meningiomas, particularly in cases that carry isolated monosomy 22, where the immune infiltrates also contain greater numbers of cytotoxic T and NK-cells associated with an enhanced anti-tumoral immune response. In line with this, the presence of regulatory T cells, is usually limited to a small fraction of all meningiomas, while frequently found in gliomas. Despite these differences between gliomas and meningiomas, both tumors show heterogeneous levels of infiltration by immune cells with variable functionality. In this review we summarize current knowledge about tumor-infiltrating immune cells in the two most common types of CNS tumors-gliomas and meningiomas-, as well as the role that such immune cells may play in the tumor microenvironment in controlling and/or promoting tumor development, growth and control.

  13. Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

    OpenAIRE

    Julio Aliberti

    2016-01-01

    Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response...

  14. Human progenitor cell recruitment via SDF-1α coacervate-laden PGS vascular grafts.

    Science.gov (United States)

    Lee, Kee-Won; Johnson, Noah R; Gao, Jin; Wang, Yadong

    2013-12-01

    Host cell recruitment is crucial for vascular graft remodeling and integration into the native blood vessel; it is especially important for cell-free strategies which rely on host remodeling. Controlled release of growth factors from vascular grafts may enhance host cell recruitment. Stromal cell-derived factor (SDF)-1α has been shown to induce host progenitor cell migration and recruitment; however, its potential in regenerative therapies is often limited due to its short half-life in vivo. This report describes a coacervate drug delivery system for enhancing progenitor cell recruitment into an elastomeric vascular graft by conferring protection of SDF-1α. Heparin and a synthetic polycation are used to form a coacervate, which is incorporated into poly(glycerol sebacate) (PGS) scaffolds. In addition to protecting SDF-1α, the coacervate facilitates uniform scaffold coating. Coacervate-laden scaffolds have high SDF-1α loading efficiency and provide sustained release under static and physiologically-relevant flow conditions with minimal initial burst release. In vitro assays showed that coacervate-laden scaffolds enhance migration and infiltration of human endothelial and mesenchymal progenitor cells by maintaining a stable SDF-1α gradient. These results suggest that SDF-1α coacervate-laden scaffolds show great promise for in situ vascular regeneration.

  15. The Role of the Immune Response in Merkel Cell Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Triozzi, Pierre L., E-mail: triozzp@ccf.org [Taussig Cancer Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195 (United States); Fernandez, Anthony P. [Departments of Dermatology and Anatomic Pathology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195 (United States)

    2013-02-28

    Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. The Merkel cell polyomavirus (MCPyV) is implicated in its pathogenesis. Immune mechanisms are also implicated. Patients who are immunosuppressed have an increased risk. There is evidence that high intratumoral T-cell counts and immune transcripts are associated with favorable survival. Spontaneous regressions implicate immune effector mechanisms. Immunogenicity is also supported by observation of autoimmune paraneoplastic syndromes. Case reports suggest that immune modulation, including reduction of immune suppression, can result in tumor regression. The relationships between MCPyV infection, the immune response, and clinical outcome, however, remain poorly understood. Circulating antibodies against MCPyV antigens are present in most individuals. MCPyV-reactive T cells have been detected in both MCC patients and control subjects. High intratumoral T-cell counts are also associated with favorable survival in MCPyV-negative MCC. That the immune system plays a central role in preventing and controlling MCC is supported by several observations. MCCs often develop, however, despite the presence of humoral and cellular immune responses. A better understanding on how MCPyV and MCC evade the immune response will be necessary to develop effective immunotherapies.

  16. Immune-Pineal Axis: Nuclear Factor κB (NF-kB Mediates the Shift in the Melatonin Source from Pinealocytes to Immune Competent Cells

    Directory of Open Access Journals (Sweden)

    Regina P. Markus

    2013-05-01

    Full Text Available Pineal gland melatonin is the darkness hormone, while extra-pineal melatonin produced by the gonads, gut, retina, and immune competent cells acts as a paracrine or autocrine mediator. The well-known immunomodulatory effect of melatonin is observed either as an endocrine, a paracrine or an autocrine response. In mammals, nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB blocks noradrenaline-induced melatonin synthesis in pinealocytes, which induces melatonin synthesis in macrophages. In addition, melatonin reduces NF-κB activation in pinealocytes and immune competent cells. Therefore, pathogen- or danger-associated molecular patterns transiently switch the synthesis of melatonin from pinealocytes to immune competent cells, and as the response progresses melatonin inhibition of NF-κB activity leads these cells to a more quiescent state. The opposite effect of NF-κB in pinealocytes and immune competent cells is due to different NF-κB dimers recruited in each phase of the defense response. This coordinated shift of the source of melatonin driven by NF-κB is called the immune-pineal axis. Finally, we discuss how this concept might be relevant to a better understanding of pathological conditions with impaired melatonin rhythms and hope it opens new horizons for the research of side effects of melatonin-based therapies.

  17. Hepatitis B Virus-Induced Parkin-Dependent Recruitment of Linear Ubiquitin Assembly Complex (LUBAC to Mitochondria and Attenuation of Innate Immunity.

    Directory of Open Access Journals (Sweden)

    Mohsin Khan

    2016-06-01

    Full Text Available Hepatitis B virus (HBV suppresses innate immune signaling to establish persistent infection. Although HBV is a DNA virus, its pre-genomic RNA (pgRNA can be sensed by RIG-I and activates MAVS to mediate interferon (IFN λ synthesis. Despite of the activation of RIG-I-MAVS axis by pgRNA, the underlying mechanism explaining how HBV infection fails to induce interferon-αβ (IFN synthesis remained uncharacterized. We demonstrate that HBV induced parkin is able to recruit the linear ubiquitin assembly complex (LUBAC to mitochondria and abrogates IFN β synthesis. Parkin interacts with MAVS, accumulates unanchored linear polyubiquitin chains on MAVS via LUBAC, to disrupt MAVS signalosome and attenuate IRF3 activation. This study highlights the novel role of parkin in antiviral signaling which involves LUBAC being recruited to the mitochondria. These results provide avenues of investigations on the role of mitochondrial dynamics in innate immunity.

  18. Innate immune pattern recognition: a cell biological perspective.

    Science.gov (United States)

    Brubaker, Sky W; Bonham, Kevin S; Zanoni, Ivan; Kagan, Jonathan C

    2015-01-01

    Receptors of the innate immune system detect conserved determinants of microbial and viral origin. Activation of these receptors initiates signaling events that culminate in an effective immune response. Recently, the view that innate immune signaling events rely on and operate within a complex cellular infrastructure has become an important framework for understanding the regulation of innate immunity. Compartmentalization within this infrastructure provides the cell with the ability to assign spatial information to microbial detection and regulate immune responses. Several cell biological processes play a role in the regulation of innate signaling responses; at the same time, innate signaling can engage cellular processes as a form of defense or to promote immunological memory. In this review, we highlight these aspects of cell biology in pattern-recognition receptor signaling by focusing on signals that originate from the cell surface, from endosomal compartments, and from within the cytosol.

  19. A novel method for monitoring functional lesion-specific recruitment of repair proteins in live cells

    Energy Technology Data Exchange (ETDEWEB)

    Woodrick, Jordan; Gupta, Suhani; Khatkar, Pooja; Dave, Kalpana; Levashova, Darya; Choudhury, Sujata; Elias, Hadi; Saha, Tapas; Mueller, Susette; Roy, Rabindra, E-mail: rr228@georgetown.edu

    2015-05-15

    Highlights: • A method of monitoring lesion-specific recruitment of proteins in vivo is described. • Recruitment of repair enzymes to abasic sites is monitored by co-localization. • Repair protein recruitment is consistent with known protein–protein relationships. • Cells demonstrated complete repair of abasic sites by 90 min. - Abstract: DNA–protein relationships have been studied by numerous methods, but a particular gap in methodology lies in the study of DNA adduct-specific interactions with proteins in vivo, which particularly affects the field of DNA repair. Using the repair of a well-characterized and ubiquitous adduct, the abasic (AP) site, as a model, we have developed a comprehensive method of monitoring DNA lesion-specific recruitment of proteins in vivo over time. We utilized a surrogate system in which a Cy3-labeled plasmid containing a single AP-site was transfected into cells, and the interaction of the labeled DNA with BER enzymes, including APE1, Polβ, LIG1, and FEN1, was monitored by immunofluorescent staining of the enzymes by Alexafluor-488-conjugated secondary antibody. The recruitment of enzymes was characterized by quantification of Cy3-Alexafluor-488 co-localization. To validate the microscopy-based method, repair of the transfected AP-site DNA was also quantified at various time points post-transfection using a real time PCR-based method. Notably, the recruitment time kinetics for each enzyme were consistent with AP-site repair time kinetics. This microscopy-based methodology is reliable in detecting the recruitment of proteins to specific DNA substrates and can be extended to study other in vivo DNA–protein relationships in any DNA sequence and in the context of any DNA structure in transfectable proliferating or quiescent cells. The method may be applied to a variety of disciplines of nucleic acid transaction pathways, including repair, replication, transcription, and recombination.

  20. Foetal immune programming: hormones, cytokines, microbes and regulatory T cells.

    Science.gov (United States)

    Hsu, Peter; Nanan, Ralph

    2014-10-01

    In addition to genetic factors, environmental cues play important roles in shaping the immune system. The first environment that the developing foetal immune system encounters is the uterus. Although physically the mother and the foetus are separated by the placental membranes, various factors such as hormones and cytokines may provide "environmental cues" to the foetal immune system. Additionally, increasing evidence suggests that prenatal maternal environmental factors, particularly microbial exposure, might significantly influence the foetal immune system, affecting long-term outcomes, a concept termed foetal immune programming. Here we discuss the potential mediators of foetal immune programming, focusing on the role of pregnancy-related hormones, cytokines and regulatory T cells, which play a critical role in immune tolerance.

  1. Cesarean section imprints cord blood immune cell distributions

    DEFF Research Database (Denmark)

    Thysen, Anna Hammerich; Larsen, Jeppe Madura; Rasmussen, Mette Annelie

    2014-01-01

    Immune programming in early life may affect the risk of developing immune-related diseases later in life. Children born by cesarean section seem to be at higher risk of asthma, allergic rhinitis, and type-1 diabetes. We hypothesized that delivery by cesarean section may affect immune maturation i...... in newborns. The objective of the study was to profile innate and adaptive immune cell subsets in cord blood of children born by cesarean section or natural birth.......Immune programming in early life may affect the risk of developing immune-related diseases later in life. Children born by cesarean section seem to be at higher risk of asthma, allergic rhinitis, and type-1 diabetes. We hypothesized that delivery by cesarean section may affect immune maturation...

  2. Memory CD8+ T Cells: Orchestrators and Key Players of Innate Immunity?

    Science.gov (United States)

    Lauvau, Grégoire; Goriely, Stanislas

    2016-09-01

    Over the past decades, the dichotomy between innate and adaptive immune responses has largely dominated our understanding of immunology. Upon primary encounter with microbial pathogens, differentiation of adaptive immune cells into functional effectors usually takes several days or even longer, making them contribute to host protection only late during primary infection. However, once generated, antigen-experienced T lymphocytes can persist in the organism and constitute a pool of memory cells that mediate fast and effective protection to a recall infection with the same microbial pathogen. Herein, we challenge this classical paradigm by highlighting the "innate nature" of memory CD8+ T cells. First, within the thymus or in the periphery, naïve CD8+ T cells may acquire phenotypic and functional characteristics of memory CD8+ T cells independently of challenge with foreign antigens. Second, both the "unconventional" and the "conventional" memory cells can rapidly express protective effector functions in response to sets of inflammatory cytokines and chemokines signals, independent of cognate antigen triggering. Third, memory CD8+ T cells can act by orchestrating the recruitment, activation, and licensing of innate cells, leading to broad antimicrobial states. Thus, collectively, memory CD8+ T cells may represent important actors of innate immune defenses.

  3. HIV-1 efficient entry in inner foreskin is mediated by elevated CCL5/RANTES that recruits T cells and fuels conjugate formation with Langerhans cells.

    Directory of Open Access Journals (Sweden)

    Zhicheng Zhou

    2011-06-01

    Full Text Available Male circumcision reduces acquisition of HIV-1 by 60%. Hence, the foreskin is an HIV-1 entry portal during sexual transmission. We recently reported that efficient HIV-1 transmission occurs following 1 h of polarized exposure of the inner, but not outer, foreskin to HIV-1-infected cells, but not to cell-free virus. At this early time point, Langerhans cells (LCs and T-cells within the inner foreskin epidermis are the first cells targeted by the virus. To gain in-depth insight into the molecular mechanisms governing inner foreskin HIV-1 entry, foreskin explants were inoculated with HIV-1-infeceted cells for 4 h. The chemokine/cytokine milieu secreted by the foreskin tissue, and resulting modifications in density and spatial distribution of T-cells and LCs, were then investigated. Our studies show that in the inner foreskin, inoculation with HIV-1-infected cells induces increased CCL5/RANTES (1.63-fold and decreased CCL20/MIP-3-alpha (0.62-fold secretion. Elevated CCL5/RANTES mediates recruitment of T-cells from the dermis into the epidermis, which is blocked by a neutralizing CCL5/RANTES Ab. In parallel, HIV-1-infected cells mediate a bi-phasic modification in the spatial distribution of epidermal LCs: attraction to the apical surface at 1 h, followed by migration back towards the basement membrane later on at 4 h, in correlation with reduced CCL20/MIP-3-alpha at this time point. T-cell recruitment fuels the continuous formation of LC-T-cell conjugates, permitting the transfer of HIV-1 captured by LCs. Together, these results reveal that HIV-1 induces a dynamic process of immune cells relocation in the inner foreskin that is associated with specific chemokines secretion, which favors efficient HIV-1 entry at this site.

  4. NK cells promote neutrophil recruitment in the brain during sepsis-induced neuroinflammation

    Science.gov (United States)

    He, Hao; Geng, Tingting; Chen, Piyun; Wang, Meixiang; Hu, Jingxia; Kang, Li; Song, Wengang; Tang, Hua

    2016-01-01

    Sepsis could affect the central nervous system and thus induces neuroinflammation, which subsequently leads to brain damage or dysfunction. However, the mechanisms of generation of neuroinflammation during sepsis remain poorly understood. By administration of lipopolysaccharides (LPS) in mice to mimic sepsis, we found that shortly after opening the blood–brain barrier, conventional CD11b+CD27+ NK subset migrated into the brain followed by subsequent neutrophil infiltration. Interestingly, depletion of NK cells prior to LPS treatment severely impaired neutrophil recruitment in the inflamed brain. By in vivo recruitment assay, we found that brain-infiltrated NK cells displayed chemotactic activity to neutrophils, which depended on the higher expression of chemokines such as CXCL2. Moreover, microglia were also responsible for neutrophil recruitment, and their chemotactic activity was significantly impaired by ablation of NK cells. Furthermore, depletion of NK cells could significantly ameliorate depression-like behavior in LPS-treated mice. These data indicated a NK cell-regulated neutrophil recruitment in the blamed brain, which also could be seen on another sepsis model, cecal ligation and puncture. So, our findings revealed an important scenario in the generation of sepsis-induced neuroinflammation. PMID:27270556

  5. Estrogen receptors regulate innate immune cells and signaling pathways.

    Science.gov (United States)

    Kovats, Susan

    2015-04-01

    Humans show strong sex differences in immunity to infection and autoimmunity, suggesting sex hormones modulate immune responses. Indeed, receptors for estrogens (ERs) regulate cells and pathways in the innate and adaptive immune system, as well as immune cell development. ERs are ligand-dependent transcription factors that mediate long-range chromatin interactions and form complexes at gene regulatory elements, thus promoting epigenetic changes and transcription. ERs also participate in membrane-initiated steroid signaling to generate rapid responses. Estradiol and ER activity show profound dose- and context-dependent effects on innate immune signaling pathways and myeloid cell development. While estradiol most often promotes the production of type I interferon, innate pathways leading to pro-inflammatory cytokine production may be enhanced or dampened by ER activity. Regulation of innate immune cells and signaling by ERs may contribute to the reported sex differences in innate immune pathways. Here we review the recent literature and highlight several molecular mechanisms by which ERs regulate the development or functional responses of innate immune cells.

  6. Paracrine factors of mesenchymal stem cells recruit macrophages and endothelial lineage cells and enhance wound healing.

    Directory of Open Access Journals (Sweden)

    Liwen Chen

    Full Text Available Bone marrow derived mesenchymal stem cells (BM-MSCs have been shown to enhance wound healing; however, the mechanisms involved are barely understood. In this study, we examined paracrine factors released by BM-MSCs and their effects on the cells participating in wound healing compared to those released by dermal fibroblasts. Analyses of BM-MSCs with Real-Time PCR and of BM-MSC-conditioned medium by antibody-based protein array and ELISA indicated that BM-MSCs secreted distinctively different cytokines and chemokines, such as greater amounts of VEGF-alpha, IGF-1, EGF, keratinocyte growth factor, angiopoietin-1, stromal derived factor-1, macrophage inflammatory protein-1alpha and beta and erythropoietin, compared to dermal fibroblasts. These molecules are known to be important in normal wound healing. BM-MSC-conditioned medium significantly enhanced migration of macrophages, keratinocytes and endothelial cells and proliferation of keratinocytes and endothelial cells compared to fibroblast-conditioned medium. Moreover, in a mouse model of excisional wound healing, where concentrated BM-MSC-conditioned medium was applied, accelerated wound healing occurred compared to administration of pre-conditioned or fibroblast-conditioned medium. Analysis of cell suspensions derived from the wound by FACS showed that wounds treated with BM-MSC-conditioned medium had increased proportions of CD4/80-positive macrophages and Flk-1-, CD34- or c-kit-positive endothelial (progenitor cells compared to wounds treated with pre-conditioned medium or fibroblast-conditioned medium. Consistent with the above findings, immunohistochemical analysis of wound sections showed that wounds treated with BM-MSC-conditioned medium had increased abundance of macrophages. Our results suggest that factors released by BM-MSCs recruit macrophages and endothelial lineage cells into the wound thus enhancing wound healing.

  7. Human intestinal dendritic cells as controllers of mucosal immunity

    Directory of Open Access Journals (Sweden)

    David Bernardo

    2013-06-01

    Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  8. Overcoming the hurdles of tumor immunity by targeting regulatory pathways in innate and adaptive immune cells.

    Science.gov (United States)

    Zwirner, Norberto W; Croci, Diego O; Domaica, Carolina I; Rabinovich, Gabriel A

    2010-01-01

    The improved understanding of the biochemical nature of tumor antigens and the identification of cellular and molecular mechanisms leading to activation of innate and adaptive immune cells have been of paramount importance in the progress of tumor immunology. Studies on the intricate network of interactions between tumor and immune cells have revealed novel regulatory signals, including cell surface inhibitory receptors and costimulatory molecules, intracellular regulatory pathways, immunosuppressive cytokines and proapoptotic mediators, which may operate in concert to orchestrate tumor-immune escape. This emerging portfolio of inhibitory checkpoints can influence the physiology of innate immune cells including dendritic cells, macrophages and natural killer (NK) cells, as well as different subsets of T cells to fine tune their effector function. The synergistic combination of strategies aimed at overcoming regulatory signals and/or stimulating effector pathways, may offer therapeutic advantage as adjuvants of conventional anticancer therapies. Based on this premise, we will discuss here how the control of the effector functions of innate and adaptive immune cells and the manipulation of regulatory pathways, either alone or in combination, could be exploited for therapeutic purposes in cancer patients.

  9. HIF-mediated innate immune responses: cell signaling and therapeutic implications

    Directory of Open Access Journals (Sweden)

    Harris AJ

    2014-05-01

    Full Text Available Alison J Harris, AA Roger Thompson, Moira KB Whyte, Sarah R Walmsley Academic Unit of Respiratory Medicine, Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Leukocytes recruited to infected, damaged, or inflamed tissues during an immune response must adapt to oxygen levels much lower than those in the circulation. Hypoxia inducible factors (HIFs are key mediators of cellular responses to hypoxia and, as in other cell types, HIFs are critical for the upregulation of glycolysis, which enables innate immune cells to produce adenosine triphosphate anaerobically. An increasing body of evidence demonstrates that hypoxia also regulates many other innate immunological functions, including cell migration, apoptosis, phagocytosis of pathogens, antigen presentation and production of cytokines, chemokines, and angiogenic and antimicrobial factors. Many of these functions are mediated by HIFs, which are not only stabilized posttranslationally by hypoxia, but also transcriptionally upregulated by inflammatory signals. Here, we review the role of HIFs in the responses of innate immune cells to hypoxia, both in vitro and in vivo, with a particular focus on myeloid cells, on which the majority of studies have so far been carried out. Keywords: hypoxia, neutrophils, monocytes, macrophages

  10. Kicking off adaptive immunity: the discovery of dendritic cells

    OpenAIRE

    Katsnelson, Alla

    2006-01-01

    In 1973, Ralph Steinman and Zanvil Cohn discovered an unusual looking population of cells with an unprecedented ability to activate naive T cells. Dubbed “dendritic cells,” these cells are now known as the primary instigators of adaptive immunity.

  11. Levels of immune cells in transcendental meditation practitioners

    Directory of Open Access Journals (Sweden)

    Jose R Infante

    2014-01-01

    Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results.

  12. Cellular factors targeting APCs to modulate adaptive T cell immunity.

    Science.gov (United States)

    Visperas, Anabelle; Do, Jeongsu; Min, Booki

    2014-01-01

    The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

  13. Cellular Factors Targeting APCs to Modulate Adaptive T Cell Immunity

    Directory of Open Access Journals (Sweden)

    Anabelle Visperas

    2014-01-01

    Full Text Available The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

  14. Immune and Inflammatory Cell Composition of Human Lung Cancer Stroma.

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    G-Andre Banat

    Full Text Available Recent studies indicate that the abnormal microenvironment of tumors may play a critical role in carcinogenesis, including lung cancer. We comprehensively assessed the number of stromal cells, especially immune/inflammatory cells, in lung cancer and evaluated their infiltration in cancers of different stages, types and metastatic characteristics potential. Immunohistochemical analysis of lung cancer tissue arrays containing normal and lung cancer sections was performed. This analysis was combined with cyto-/histomorphological assessment and quantification of cells to classify/subclassify tumors accurately and to perform a high throughput analysis of stromal cell composition in different types of lung cancer. In human lung cancer sections we observed a significant elevation/infiltration of total-T lymphocytes (CD3+, cytotoxic-T cells (CD8+, T-helper cells (CD4+, B cells (CD20+, macrophages (CD68+, mast cells (CD117+, mononuclear cells (CD11c+, plasma cells, activated-T cells (MUM1+, B cells, myeloid cells (PD1+ and neutrophilic granulocytes (myeloperoxidase+ compared with healthy donor specimens. We observed all of these immune cell markers in different types of lung cancers including squamous cell carcinoma, adenocarcinoma, adenosquamous cell carcinoma, small cell carcinoma, papillary adenocarcinoma, metastatic adenocarcinoma, and bronchioloalveolar carcinoma. The numbers of all tumor-associated immune cells (except MUM1+ cells in stage III cancer specimens was significantly greater than those in stage I samples. We observed substantial stage-dependent immune cell infiltration in human lung tumors suggesting that the tumor microenvironment plays a critical role during lung carcinogenesis. Strategies for therapeutic interference with lung cancer microenvironment should consider the complexity of its immune cell composition.

  15. Cell signaling in the interaction between pathogenic bacteria and immune cells.

    Science.gov (United States)

    Yang, Hui; Liu, Yaxiong; Tang, Ruihua; Shao, Dongyan; Li, Jing; Li, Ji; Ye, Linjie; Jin, Mingliang; Huang, Qingsheng; Shi, Junling

    2015-06-01

    Cell signaling is an essential part in the complex system of communication that governs basic cellular activities and coordinates cell actions. The ability of cells to perceive and correctly respond to their microenvironment is essential for cell survival and basic biological function. In the defense from pathogenic bacteria, the immune cells exert their function through various signaling pathways. In this review, we will summarize recent findings on the role of cell signaling in the interaction between pathogenic bacteria and immune cells, focusing on neutrophils and macrophages, which are part of the innate immunity, and also T cells, which are components of the adaptive immune system.

  16. Basophil-derived IL-6 regulates TH17 cell differentiation and CD4 T cell immunity

    Science.gov (United States)

    Yuk, Chae Min; Park, Hyeung Ju; Kwon, Bo-In; Lah, Sang Joon; Chang, Jun; Kim, Ji-Young; Lee, Kyung-Mi; Park, Su-Hyung; Hong, Seokchan; Lee, Seung-Hyo

    2017-01-01

    Basophils are rare, circulating granulocytes proposed to be involved in T helper (TH) type 2 immunity, mainly through secretion of interleukin (IL)-4. In addition to IL-4, basophils produce IL-6 and tumor necrosis factor (TNF)-α in response to immunoglobulin E (IgE) crosslinking. Differentiation of TH17 cells requires IL-6 and transforming growth factor (TGF)-β, but whether basophils play a significant role in TH17 induction is unknown. Here we show a role for basophils in TH17 cell development by using in vitro T cell differentiation and in vivo TH17-mediated inflammation models. Bone marrow derived-basophils (BMBs) and splenic basophils produce significant amounts of IL-6 as well as IL-4 following stimulation with IgE crosslink or cholera toxin (CT). In addition, through IL-6 secretion, BMBs cooperate with dendritic cells to promote TH17 cell differentiation. In the TH17 lung inflammation model, basophils are recruited to the inflamed lungs following CT challenge, and TH17 responses are significantly reduced in the absence of basophils or IL-6. Furthermore, reconstitution with wild-type, but not IL-6-deficient, basophils restored CT-mediated lung inflammation. Lastly, basophil-deficient mice showed reduced phenotypes of TH17-dependent experimental autoimmune encephalomyelitis. Therefore, our results indicate that basophils are an important inducer of TH17 cell differentiation, which is dependent on IL-6 secretion. PMID:28134325

  17. The mobilization and recruitment of c-kit+ cells contribute to wound healing after surgery.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Takemoto

    Full Text Available Delayed wound healing is a serious clinical problem in patients after surgery. A recent study has demonstrated that bone marrow-derived c-kit-positive (c-kit(+ cells play important roles in repairing and regenerating various tissues and organs. To examine the hypothesis that surgical injury induces the mobilization and recruitment of c-kit+ cells to accelerate wound healing. Mice were subjected to a left pneumonectomy. The mobilization of c-kit+ cells was monitored after surgery. Using green fluorescent protein (GFP(+ bone marrow-transplanted chimera mice, we investigated further whether the mobilized c-kit+ cells were recruited to effect wound healing in a skin puncture model. The group with left pneumonectomies increased the c-kit(+ and CD34(+ stem cells in peripheral blood 24 h after surgery. At 3 days after surgery, the skin wound size was observed to be significantly smaller, and the number of bone marrow-derived GFP(+ cells and GFP(+/c-kit+ cells in the wound tissue was significantly greater in mice that had received pneumonectomies, as compared with those that had received a sham operation. Furthermore, some of these GFP(+ cells were positively expressed specific markers of macrophages (F4/80, endothelial cells (CD31, and myofibroblasts (αSMA. The administration of AMD3100, an antagonist of a stromal-cell derived factor (SDF-1/CXCR4 signaling pathway, reduced the number of GFP(+ cells in wound tissue and completely negated the accelerated wound healing. Surgical injury induces the mobilization and recruitment of c-kit+ cells to contribute to wound healing. Regulating c-kit+ cells may provide a new approach that accelerates wound healing after surgery.

  18. The Type IVa Pilus Machinery Is Recruited to Sites of Future Cell Division.

    Science.gov (United States)

    Carter, Tyson; Buensuceso, Ryan N C; Tammam, Stephanie; Lamers, Ryan P; Harvey, Hanjeong; Howell, P Lynne; Burrows, Lori L

    2017-01-31

    Type IVa pili (T4aP) are ubiquitous microbial appendages used for adherence, twitching motility, DNA uptake, and electron transfer. Many of these functions depend on dynamic assembly and disassembly of the pilus by a megadalton-sized, cell envelope-spanning protein complex located at the poles of rod-shaped bacteria. How the T4aP assembly complex becomes integrated into the cell envelope in the absence of dedicated peptidoglycan (PG) hydrolases is unknown. After ruling out the potential involvement of housekeeping PG hydrolases in the installation of the T4aP machinery in Pseudomonas aeruginosa, we discovered that key components of inner (PilMNOP) and outer (PilQ) membrane subcomplexes are recruited to future sites of cell division. Midcell recruitment of a fluorescently tagged alignment subcomplex component, mCherry-PilO, depended on PilQ secretin monomers-specifically, their N-terminal PG-binding AMIN domains. PilP, which connects PilO to PilQ, was required for recruitment, while PilM, which is structurally similar to divisome component FtsA, was not. Recruitment preceded secretin oligomerization in the outer membrane, as loss of the PilQ pilotin PilF had no effect on localization. These results were confirmed in cells chemically blocked for cell division prior to outer membrane invagination. The hub protein FimV and a component of the polar organelle coordinator complex-PocA-were independently required for midcell recruitment of PilO and PilQ. Together, these data suggest an integrated, energy-efficient strategy for the targeting and preinstallation-rather than retrofitting-of the T4aP system into nascent poles, without the need for dedicated PG-remodeling enzymes.

  19. The Type IVa Pilus Machinery Is Recruited to Sites of Future Cell Division

    Science.gov (United States)

    Carter, Tyson; Buensuceso, Ryan N. C.; Tammam, Stephanie; Lamers, Ryan P.; Harvey, Hanjeong

    2017-01-01

    ABSTRACT Type IVa pili (T4aP) are ubiquitous microbial appendages used for adherence, twitching motility, DNA uptake, and electron transfer. Many of these functions depend on dynamic assembly and disassembly of the pilus by a megadalton-sized, cell envelope-spanning protein complex located at the poles of rod-shaped bacteria. How the T4aP assembly complex becomes integrated into the cell envelope in the absence of dedicated peptidoglycan (PG) hydrolases is unknown. After ruling out the potential involvement of housekeeping PG hydrolases in the installation of the T4aP machinery in Pseudomonas aeruginosa, we discovered that key components of inner (PilMNOP) and outer (PilQ) membrane subcomplexes are recruited to future sites of cell division. Midcell recruitment of a fluorescently tagged alignment subcomplex component, mCherry-PilO, depended on PilQ secretin monomers—specifically, their N-terminal PG-binding AMIN domains. PilP, which connects PilO to PilQ, was required for recruitment, while PilM, which is structurally similar to divisome component FtsA, was not. Recruitment preceded secretin oligomerization in the outer membrane, as loss of the PilQ pilotin PilF had no effect on localization. These results were confirmed in cells chemically blocked for cell division prior to outer membrane invagination. The hub protein FimV and a component of the polar organelle coordinator complex—PocA—were independently required for midcell recruitment of PilO and PilQ. Together, these data suggest an integrated, energy-efficient strategy for the targeting and preinstallation—rather than retrofitting—of the T4aP system into nascent poles, without the need for dedicated PG-remodeling enzymes. PMID:28143978

  20. Original encounter with antigen determines antigen-presenting cell imprinting of the quality of the immune response in mice.

    Directory of Open Access Journals (Sweden)

    Valérie Abadie

    Full Text Available BACKGROUND: Obtaining a certain multi-functionality of cellular immunity for the control of infectious diseases is a burning question in immunology and in vaccine design. Early events, including antigen shuttling to secondary lymphoid organs and recruitment of innate immune cells for adaptive immune response, determine host responsiveness to antigens. However, the sequence of these events and their impact on the quality of the immune response remain to be elucidated. Here, we chose to study Modified Vaccinia virus Ankara (MVA which is now replacing live Smallpox vaccines and is proposed as an attenuated vector for vaccination strategies against infectious diseases. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed in vivo mechanisms triggered following intradermal (i.d. and intramuscular (i.m. Modified Vaccinia virus Ankara (MVA administration. We demonstrated significant differences in the antigen shuttling to lymphoid organs by macrophages (MPhis, myeloid dendritic cells (DCs, and neutrophils (PMNs. MVA i.d. administration resulted in better antigen distribution and more sustained antigen-presenting cells (APCs recruitment into draining lymph nodes than with i.m. administration. These APCs, which comprise both DCs and MPhis, were differentially involved in T cell priming and shaped remarkably the quality of cytokine-producing virus-specific T cells according to the entry route of MVA. CONCLUSIONS/SIGNIFICANCE: This study improves our understanding of the mechanisms of antigen delivery and their consequences on the quality of immune responses and provides new insights for vaccine development.

  1. LUBAC-Recruited CYLD and A20 Regulate Gene Activation and Cell Death by Exerting Opposing Effects on Linear Ubiquitin in Signaling Complexes

    Directory of Open Access Journals (Sweden)

    Peter Draber

    2015-12-01

    Full Text Available Ubiquitination and deubiquitination are crucial for assembly and disassembly of signaling complexes. LUBAC-generated linear (M1 ubiquitin is important for signaling via various immune receptors. We show here that the deubiquitinases CYLD and A20, but not OTULIN, are recruited to the TNFR1- and NOD2-associated signaling complexes (TNF-RSC and NOD2-SC, at which they cooperate to limit gene activation. Whereas CYLD recruitment depends on its interaction with LUBAC, but not on LUBAC’s M1-chain-forming capacity, A20 recruitment requires this activity. Intriguingly, CYLD and A20 exert opposing effects on M1 chain stability in the TNF-RSC and NOD2-SC. While CYLD cleaves M1 chains, and thereby sensitizes cells to TNF-induced death, A20 binding to them prevents their removal and, consequently, inhibits cell death. Thus, CYLD and A20 cooperatively restrict gene activation and regulate cell death via their respective activities on M1 chains. Hence, the interplay between LUBAC, M1-ubiquitin, CYLD, and A20 is central for physiological signaling through innate immune receptors.

  2. Primary immune system responders to nucleus pulposus cells: evidence for immune response in disc herniation

    Directory of Open Access Journals (Sweden)

    K Murai

    2010-01-01

    Full Text Available Although intervertebral disc herniation and associated sciatica is a common disease, its molecular pathogenesis is not well understood. Immune responses are thought to be involved. This study provides direct evidence that even non-degenerated nucleus pulposus (NP cells elicit immune responses. An in vitro colony forming inhibition assay demonstrated the suppressive effects of autologous spleen cells on NP cells and an in vitro cytotoxicity assay showed the positive cytotoxic effects of natural killer (NK cells and macrophages on NP cells. Non-degenerated rat NP tissues transplanted into wild type rats and immune-deficient mice demonstrated a significantly higher NP cell survival rate in immune-deficient mice. Immunohistochemical staining showed the presence of macrophages and NK cells in the transplanted NP tissues. These results suggest that even non-degenerated autologous NP cells are recognized by macrophages and NK cells, which may have an immunological function in the early phase of disc herniation. These findings contribute to understanding resorption and the inflammatory reaction to disc herniation.

  3. Tumor-infiltrating immune cells and prognosis: the potential link between conventional cancer therapy and immunity.

    Science.gov (United States)

    Jochems, Caroline; Schlom, Jeffrey

    2011-05-01

    Numerous studies have now documented a link between the immune infiltrate in several human carcinoma types and prognosis and response to therapy. The most comprehensive of these studies were in colorectal cancer with similar conclusions by numerous groups. Analyses of immune infiltrate of several other carcinoma types also showed general correlations between immune infiltrate and prognosis, but with some conflicting results. This review will attempt to summarize the current state of this field and point out what factors may be responsible for some of the conflicting findings. Nonetheless, the breadth of reports drawing similar conclusions for some cancer cell types leads one to more seriously consider the link between immune cell infiltrate and tumor prognosis and/or response to therapy, and the potential for combining conventional cancer therapy with active immunotherapy employing therapeutic cancer vaccines.

  4. Immune Cell Isolation from Mouse Femur Bone Marrow

    OpenAIRE

    Liu, Xiaoyu; Quan, Ning

    2015-01-01

    The bone marrow is the site of hematopoesis and contains mixed population of blood cells including erythrocytes, granulocytes, monocytes, dendritic cells, lymphocytes and hematopoietic stem cells. The following protocol provides a simple and fast method for isolation of bone marrow immune cells (no erythrocytes) from mouse femurs with a yield of approximate 8 × 107 cells in 5 ml culture media (1.6 × 104 cells/μl). Further isolation or flow cytometric analysis might be required for study of sp...

  5. REST-mediated recruitment of polycomb repressor complexes in mammalian cells

    DEFF Research Database (Denmark)

    Dietrich, Nikolaj; Lerdrup, Mads; Landt, Eskild

    2012-01-01

    Polycomb Repressive Complex (PRC) 1 and PRC2 regulate genes involved in differentiation and development. However, the mechanism for how PRC1 and PRC2 are recruited to genes in mammalian cells is unclear. Here we present evidence for an interaction between the transcription factor REST, PRC1......, and increased gene expression. Genome-wide analysis of Polycomb binding in Rest¿/¿ and Eed¿/¿ mouse embryonic stem (mES) cells showed that Rest was required for PRC1 recruitment to a subset of Polycomb regulated neuronal genes. Furthermore, we found that PRC1 can be recruited to Rest binding sites independently...... of CpG islands and the H3K27Me3 mark. Surprisingly, PRC2 was frequently increased around Rest binding sites located in CpG-rich regions in the Rest¿/¿ mES cells, indicating a more complex interplay where Rest also can limit PRC2 recruitment. Therefore, we propose that Rest has context...

  6. Attraction and activation of dendritic cells at the site of tumor elicits potent antitumor immunity.

    Science.gov (United States)

    Lapteva, Natalia; Aldrich, Melissa; Rollins, Lisa; Ren, Wenhong; Goltsova, Tatiana; Chen, Si-Yi; Huang, Xue F

    2009-09-01

    Tumor cells harbor unique genetic mutations, which lead to the generation of immunologically foreign antigenic peptide repertoire with the potential to induce individual tumor-specific immune responses. Here, we developed an in situ tumor vaccine with the ability to elicit antitumor immunity. This vaccine comprised an E1B-deleted oncolytic adenovirus expressing beta-defensin-2 (Ad-BD2-E1A) for releasing tumor antigens, recruiting and activating plasmacytoid dendritic cells (pDCs). Intratumoral injections of Ad-BD2-E1A vaccine inhibited primary breast tumor growth and blocked naturally occurring metastasis in mice. Ad-BD2-E1A vaccination induced potent tumor-specific T-cell responses. Splenic and intratumoral DCs isolated from Ad-BD2-E1A-immunized mice were able to stimulate or promote the differentiation of naive T cells into tumor-specific cytotoxic T cells. We further found that the increased numbers of mature CD45RA(+)CD8alpha(+)CD40(+) pDCs infiltrated into Ad-BD2-E1A-treated tumors. The antitumor effect of Ad-BD2-E1A vaccination was abrogated in toll-like receptor 4 (TLR4) deficient mice, suggesting the critical role of TLR4 in the induction of antitumor immunity by Ad-BD2-E1A. The results of this study indicate that in situ vaccination with the oncolytic BD2-expressing adenovirus preferentially attracts pDCs and promotes their maturation, and thus elicits potent tumor-specific immunity. This vaccine represents an attractive therapeutic strategy for the induction of individualized antitumor immunity.

  7. The role of SLAM family receptors in immune cell signaling.

    Science.gov (United States)

    Ostrakhovitch, Elena A; Li, Shawn S-C

    2006-12-01

    The signaling lymphocyte-activating molecule (SLAM) family immunoreceptors are expressed in a wide array of immune cells, including both T and B lymphocytes. By virtue of their ability to transduce tyrosine phosphorylation signals through the so-called ITSM (immunoreceptor tyrosine-based switch motif) sequences, they play an important part in regulating both innate and adaptive immune responses. The critical role of the SLAM immunoreceptors in mediating normal immune reactions was highlighted in recent findings that SAP, a SLAM-associated protein, modulates the activities of various immune cells through interactions with different members of the SLAM family expressed in these cells. Importantly, mutations or deletions of the sap gene in humans result in the X-linked lymphoproliferative syndrome. In this review, we summarize current knowledge and survey the latest developments in signal transduction events triggered by the activation of SLAM family receptors in different cell types.

  8. Antigen-induced recruitment of eosinophils: importance of CD4+ T cells, IL5, and mast cells.

    Science.gov (United States)

    Hom, J T; Estridge, T

    1994-12-01

    Eosinophils of sensitized mice readily recruit to the site of antigen challenge. In the present study, experiments were performed to determine the involvement of different cell types in the antigen-induced recruitment of eosinophils. We demonstrated that a single treatment with anti-L3T4 monoclonal antibody (mAb) on the day of allergen challenge significantly decreased antigen-induced recruitment of eosinophils. Treatments with anti-L3T4 mAb during the sensitization period also caused a substantial reduction in the migration of eosinophils into the site of challenge with antigen. Thus, it appears that both stages of eosinophil recruitment, sensitization and antigen-challenge, are dependent upon the presence of L3T4+ T cells. Moreover, while treatments with anti-IL5 mAb blocked eosinophil migration, anti-IL2 mAb failed to alter the antigen-induced recruitment of eosinophils. In addition, significant numbers of eosinophils from the mast-cell-deficient mice were found to migrate into the peritoneal cavities upon allergen challenge. Eosinophil migration was also observed in several mouse strains of different H-2 haplotypes. The present findings suggest that CD4+ T cells and IL5 but not IL2 may play important roles in modulating the recruitment of eosinophils. Moreover, the involvement of mast cells does not appear to be essential for eosinophil migration. Finally, the development of antigen-induced recruitment of eosinophils is probably not under the immunogenetic regulation by genes within the H-2 complex.

  9. The Principles of Engineering Immune Cells to Treat Cancer.

    Science.gov (United States)

    Lim, Wendell A; June, Carl H

    2017-02-09

    Chimeric antigen receptor (CAR) T cells have proven that engineered immune cells can serve as a powerful new class of cancer therapeutics. Clinical experience has helped to define the major challenges that must be met to make engineered T cells a reliable, safe, and effective platform that can be deployed against a broad range of tumors. The emergence of synthetic biology approaches for cellular engineering is providing us with a broadly expanded set of tools for programming immune cells. We discuss how these tools could be used to design the next generation of smart T cell precision therapeutics.

  10. Conditional IL-4/IL-13-deficient mice reveal a critical role of innate immune cells for protective immunity against gastrointestinal helminths.

    Science.gov (United States)

    Oeser, K; Schwartz, C; Voehringer, D

    2015-05-01

    Approximately one-third of the world population is infected with gastrointestinal helminths. Studies in mouse models have demonstrated that the cytokines interleukin (IL)-4 and IL-13 are essential for worm expulsion, but the critical cellular source of these cytokines is poorly defined. Here, we compared the immune response to Nippostrongylus brasiliensis in wild-type, T cell-specific IL-4/IL-13-deficient and general IL-4/IL-13-deficient mice. We show that T cell-derived IL-4/IL-13 promoted T helper 2 (Th2) polarization in a paracrine manner, differentiation of alternatively activated macrophages, and tissue recruitment of innate effector cells. However, innate IL-4/IL-13 played the critical role for induction of goblet cell hyperplasia and secretion of effector molecules like Mucin5ac and RELMβ in the small intestine. Surprisingly, T cell-specific IL-4/IL-13-deficient and wild-type mice cleared the parasite with comparable efficiency, whereas IL-4/IL-13-deficient mice showed impaired expulsion. These findings demonstrate that IL-4/IL-13 produced by cells of the innate immune system is required and sufficient to initiate effective type 2 immune responses resulting in protective immunity against N. brasiliensis.

  11. Human immune cell targeting of protein nanoparticles - caveospheres

    Science.gov (United States)

    Glass, Joshua J.; Yuen, Daniel; Rae, James; Johnston, Angus P. R.; Parton, Robert G.; Kent, Stephen J.; de Rose, Robert

    2016-04-01

    Nanotechnology has the power to transform vaccine and drug delivery through protection of payloads from both metabolism and off-target effects, while facilitating specific delivery of cargo to immune cells. However, evaluation of immune cell nanoparticle targeting is conventionally restricted to monocultured cell line models. We generated human caveolin-1 nanoparticles, termed caveospheres, which were efficiently functionalized with monoclonal antibodies. Using this platform, we investigated CD4+ T cell and CD20+ B cell targeting within physiological mixtures of primary human blood immune cells using flow cytometry, imaging flow cytometry and confocal microscopy. Antibody-functionalization enhanced caveosphere binding to targeted immune cells (6.6 to 43.9-fold) within mixed populations and in the presence of protein-containing fluids. Moreover, targeting caveospheres to CCR5 enabled caveosphere internalization by non-phagocytic CD4+ T cells--an important therapeutic target for HIV treatment. This efficient and flexible system of immune cell-targeted caveosphere nanoparticles holds promise for the development of advanced immunotherapeutics and vaccines.

  12. Mitochondrial Dysfunction and Immune Cell Metabolism in Sepsis

    Science.gov (United States)

    2017-01-01

    Sepsis is a life threatening condition mediated by systemic infection, but also triggered by hemorrhage and trauma. These are significant causes of organ injury implicated in morbidity and mortality, as well as post-sepsis complications associated with dysfunction of innate and adaptive immunity. The role of cellular bioenergetics and loss of metabolic plasticity of immune cells is increasingly emerging in the pathogenesis of sepsis. This review describes mitochondrial biology and metabolic alterations of immune cells due to sepsis, as well as indicates plausible therapeutic opportunities.

  13. Arginine Metabolism in Myeloid Cells Shapes Innate and Adaptive Immunity

    Science.gov (United States)

    Rodriguez, Paulo C.; Ochoa, Augusto C.; Al-Khami, Amir A.

    2017-01-01

    Arginine metabolism has been a key catabolic and anabolic process throughout the evolution of the immune response. Accruing evidence indicates that arginine-catabolizing enzymes, mainly nitric oxide synthases and arginases, are closely integrated with the control of immune response under physiological and pathological conditions. Myeloid cells are major players that exploit the regulators of arginine metabolism to mediate diverse, although often opposing, immunological and functional consequences. In this article, we focus on the importance of arginine catabolism by myeloid cells in regulating innate and adaptive immunity. Revisiting this matter could result in novel therapeutic approaches by which the immunoregulatory nodes instructed by arginine metabolism can be targeted.

  14. Integrating innate and adaptive immune cells: Mast cells as crossroads between regulatory and effector B and T cells.

    Science.gov (United States)

    Mekori, Yoseph A; Hershko, Alon Y; Frossi, Barbara; Mion, Francesca; Pucillo, Carlo E

    2016-05-05

    A diversity of immune mechanisms have evolved to protect normal tissues from infection, but from immune damage too. Innate cells, as well as adaptive cells, are critical contributors to the correct development of the immune response and of tissue homeostasis. There is a dynamic "cross-talk" between the innate and adaptive immunomodulatory mechanisms for an integrated control of immune damage as well as the development of the immune response. Mast cells have shown a great plasticity, modifying their behavior at different stages of immune response through interaction with effector and regulatory populations of adaptive immunity. Understanding the interplays among T effectors, regulatory T cells, B cells and regulatory B cells with mast cells will be critical in the future to assist in the development of therapeutic strategies to enhance and synergize physiological immune-modulator and -suppressor elements in the innate and adaptive immune system.

  15. The architects of B and T cell immune responses.

    Science.gov (United States)

    Lane, Peter J L

    2008-08-15

    Published work links adult lymphoid tissue-inducer cells (LTi) with T cell-dependent antibody responses. In this issue of Immunity, Tsuji et al. (2008) associate LTi with T cell-independent IgA antibody responses in the gut.

  16. Regulation of the human cathelicidin antimicrobial peptide gene by 1α,25-dihydroxyvitamin D3 in primary immune cells.

    Science.gov (United States)

    Lowry, Malcolm B; Guo, Chunxiao; Borregaard, Niels; Gombart, Adrian F

    2014-09-01

    Production of the human cathelicidin antimicrobial peptide gene (hCAP18/LL-37), is regulated by 1α,25-dihydroxyvitamin D3 (1,25D3) and is critical in the killing of pathogens by innate immune cells. In addition, secreted LL-37 binds extracellular receptors and modulates the recruitment and activity of both innate and adaptive immune cells. Evidence suggests that during infections activated immune cells locally produce increased levels of 1,25D3 thus increasing production of hCAP18/LL-37. The relative expression levels of hCAP18/LL-37 among different immune cell types are not well characterized. The aim of this study was to determine the relative levels of hCAP18/LL-37 in human peripheral blood immune cells and determine to what extent 1,25D3 increased its expression in peripheral blood-derived cells. We show for the first time, a hierarchy of expression of hCAP18 in freshly isolated cells with low levels in lymphocytes, intermediate levels in monocytes and the highest levels found in neutrophils. In peripheral blood-derived cells, the highest levels of hCAP18 following treatment with 1,25D3 were in macrophages, while comparatively lower levels were found in GM-CSF-derived dendritic cells and osteoclasts. We also tested whether treatment with parathyroid hormone in combination with 1,25D3 would enhance hCAP18 induction as has been reported in skin cells, but we did not find enhancement in any immune cells tested. Our results indicate that hCAP18 is expressed at different levels according to cell type and lineage. Furthermore, potent induction of hCAP18 by 1,25D3 in macrophages and dendritic cells may modulate functions of both innate and adaptive immune cells at sites of infection.

  17. Balancing immune protection and immune pathology by CD8+ T cell responses to influenza infection

    Directory of Open Access Journals (Sweden)

    Susu eDuan

    2016-02-01

    Full Text Available Influenza A virus (IAV is a significant human pathogen causing annual epidemics and periodic pandemics. CD8+ cytotoxic T lymphocyte (CTL-mediated immunity contributes to clearance of virus-infected cells; CTL immunity targeting the conserved internal proteins of IAVs is a key protection mechanism when neutralizing antibodies are absent during heterosubtypic IAV infection. However, CTL infiltration into the airways, their cytotoxicity, and the effects of produced pro-inflammatory cytokines can cause severe lung tissue injury, thereby contributing to immunopathology. Studies have discovered complicated and exquisite stimulatory and inhibitory mechanisms that regulate CTL magnitude and effector activities during IAV infection. Here, we review the state of knowledge on the roles of IAV-specific CTLs in immune protection and immunopathology during IAV infection in animal models, highlighting the key findings of various requirements and constraints regulating the balance of immune protection and pathology involved in CTL immunity. We also discuss the evidence of cross-reactive CTL immunity as a positive correlate of cross-subtype protection during secondary IAV infection in both animal and human studies. We argue that the effects of CTL immunity on protection and immunopathology depend on multiple layers of host and viral factors, including complex host mechanisms to regulate CTL magnitude and effector activity, the pathogenic nature of the IAV, the innate response milieu, and the host historical immune context of influenza infection. Future efforts are needed to further understand these key host and viral factors, especially to differentiate those that constrain optimally effective CTL anti-viral immunity from those necessary to restrain CTL-mediated nonspecific immunopathology in the various contexts of IAV infection, in order to develop better vaccination and therapeutic strategies for modifying protective CTL immunity.

  18. Role of natural killer cells in antibacterial immunity.

    Science.gov (United States)

    Schmidt, Stanislaw; Ullrich, Evelyn; Bochennek, Konrad; Zimmermann, Stefanie-Yvonne; Lehrnbecher, Thomas

    2016-12-01

    Bacteria are a significant cause of infectious complications, in particular in immunocompromised patients. There is an increasing understanding that Natural Killer (NK) cells not only exhibit direct activity against bacteria, but also exert indirect antibacterial activity through interaction with other immune cells via cytokines and interferons. Areas covered: This review seeks to give a global overview of in vitro and in vivo data how NK cells interact with bacteria. In this regard, the review describes how NK cells directly damage and kill bacteria by soluble factors such as perforin, the impact of NK cells on other arms of the immune system, as well as how bacteria may inhibit NK cell activities. Expert commentary: A better characterization of the antibacterial effects of NK cells is urgently needed. With a better understanding of the interaction of NK cells and bacteria, NK cells may become a promising tool to prevent or to combat bacterial infections, e.g. by adoptively transferring NK cells to immunocompromised patients.

  19. Apoptosis in immune cells induced by fission fragment 147Pm

    Institute of Scientific and Technical Information of China (English)

    ZhuShou-Peng; ZhangLan-Sheng; 等

    1997-01-01

    Apoptosis in human acute lymphoblastic leukemia cell line Molt-4 cell and macrophage cell line Ana-1 cell could be induced by fission fragment 147Pm,The cumulative absorption dose of 147Pm in cultural cells through different periods were estimated.By using fluorescence microscopy and microautoradiographic tracing it can be found that Molt-4 and Anal-1 cells internally irradiated by 147Pm,displayed an obvious nuclear fragmentation and a marked phknosis in immune cell nucei,as well as DNA chain fragmentation and apoptotic bodies formation.The microautoradiographic study showed that 147Pm could infiltrate thourgh cell membrane and displayed membrane-seeking condensation in cells.At the same time.the membrane-bounded apoptotic bodies were observed.Experimental results in recent study provide evidence that Molt-4 and Ano-1 immune cells undergo apoptosis while internally irradiated with 147Pm.

  20. Dengue virus inhibits immune responses in Aedes aegypti cells.

    Directory of Open Access Journals (Sweden)

    Shuzhen Sim

    Full Text Available The ability of many viruses to manipulate the host antiviral immune response often results in complex host-pathogen interactions. In order to study the interaction of dengue virus (DENV with the Aedes aegypti immune response, we have characterized the DENV infection-responsive transcriptome of the immune-competent A. aegypti cell line Aag2. As in mosquitoes, DENV infection transcriptionally activated the cell line Toll pathway and a variety of cellular physiological systems. Most notably, however, DENV infection down-regulated the expression levels of numerous immune signaling molecules and antimicrobial peptides (AMPs. Functional assays showed that transcriptional induction of AMPs from the Toll and IMD pathways in response to bacterial challenge is impaired in DENV-infected cells. In addition, Escherichia coli, a gram-negative bacteria species, grew better when co-cultured with DENV-infected cells than with uninfected cells, suggesting a decreased production of AMPs from the IMD pathway in virus-infected cells. Pre-stimulation of the cell line with gram-positive bacteria prior to DENV infection had no effect on DENV titers, while pre-stimulation with gram-negative bacteria resulted in an increase in DENV titers. These results indicate that DENV is capable of actively suppressing immune responses in the cells it infects, a phenomenon that may have important consequences for virus transmission and insect physiology.

  1. Stress Hyperglycemia, Insulin Treatment, and Innate Immune Cells

    Directory of Open Access Journals (Sweden)

    Fangming Xiu

    2014-01-01

    Full Text Available Hyperglycemia (HG and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

  2. Mucosal Regulatory T Cells and T Helper 17 Cells in HIV-Associated Immune Activation.

    Science.gov (United States)

    Pandiyan, Pushpa; Younes, Souheil-Antoine; Ribeiro, Susan Pereira; Talla, Aarthi; McDonald, David; Bhaskaran, Natarajan; Levine, Alan D; Weinberg, Aaron; Sekaly, Rafick P

    2016-01-01

    Residual mucosal inflammation along with chronic systemic immune activation is an important feature in individuals infected with human immunodeficiency virus (HIV), and has been linked to a wide range of co-morbidities, including malignancy, opportunistic infections, immunopathology, and cardiovascular complications. Although combined antiretroviral therapy (cART) can reduce plasma viral loads to undetectable levels, reservoirs of virus persist, and increased mortality is associated with immune dysbiosis in mucosal lymphoid tissues. Immune-based therapies are pursued with the goal of improving CD4(+) T-cell restoration, as well as reducing chronic immune activation in cART-treated patients. However, the majority of research on immune activation has been derived from analysis of circulating T cells. How immune cell alterations in mucosal tissues contribute to HIV immune dysregulation and the associated risk of non-infectious chronic complications is less studied. Given the significant differences between mucosal T cells and circulating T cells, and the immediate interactions of mucosal T cells with the microbiome, more attention should be devoted to mucosal immune cells and their contribution to systemic immune activation in HIV-infected individuals. Here, we will focus on mucosal immune cells with a specific emphasis on CD4(+) T lymphocytes, such as T helper 17 cells and CD4(+)Foxp3(+) regulatory T cells (Tregs), which play crucial roles in maintaining mucosal barrier integrity and preventing inflammation, respectively. We hypothesize that pro-inflammatory milieu in cART-treated patients with immune activation significantly contributes to enhanced loss of Th17 cells and increased frequency of dysregulated Tregs in the mucosa, which in turn may exacerbate immune dysfunction in HIV-infected patients. We also present initial evidence to support this hypothesis. A better comprehension of how pro-inflammatory milieu impacts these two types of cells in the mucosa will

  3. Recruited brain tumor-derived mesenchymal stem cells contribute to brain tumor progression.

    Science.gov (United States)

    Behnan, Jinan; Isakson, Pauline; Joel, Mrinal; Cilio, Corrado; Langmoen, Iver A; Vik-Mo, Einar O; Badn, Wiaam

    2014-05-01

    The identity of the cells that contribute to brain tumor structure and progression remains unclear. Mesenchymal stem cells (MSCs) have recently been isolated from normal mouse brain. Here, we report the infiltration of MSC-like cells into the GL261 murine glioma model. These brain tumor-derived mesenchymal stem cells (BT-MSCs) are defined with the phenotype (Lin-Sca-1+CD9+CD44+CD166+/-) and have multipotent differentiation capacity. We show that the infiltration of BT-MSCs correlates to tumor progression; furthermore, BT-MSCs increased the proliferation rate of GL261 cells in vitro. For the first time, we report that the majority of GL261 cells expressed mesenchymal phenotype under both adherent and sphere culture conditions in vitro and that the non-MSC population is nontumorigenic in vivo. Although the GL261 cell line expressed mesenchymal phenotype markers in vitro, most BT-MSCs are recruited cells from host origin in both wild-type GL261 inoculated into green fluorescent protein (GFP)-transgenic mice and GL261-GFP cells inoculated into wild-type mice. We show the expression of chemokine receptors CXCR4 and CXCR6 on different recruited cell populations. In vivo, the GL261 cells change marker profile and acquire a phenotype that is more similar to cells growing in sphere culture conditions. Finally, we identify a BT-MSC population in human glioblastoma that is CD44+CD9+CD166+ both in freshly isolated and culture-expanded cells. Our data indicate that cells with MSC-like phenotype infiltrate into the tumor stroma and play an important role in tumor cell growth in vitro and in vivo. Thus, we suggest that targeting BT-MSCs could be a possible strategy for treating glioblastoma patients.

  4. Preferential recruitment of Th17 cells to cervical cancer via CCR6-CCL20 pathway.

    Science.gov (United States)

    Yu, Qing; Lou, Xiang-ming; He, Yan

    2015-01-01

    Our previous studies suggest that Th17 cells accumulate within tumor tissues and correlate with recurrence of cervical cancer patients. However, the source of the increased tumor-infiltrating Th17 cells remains poorly understood. We investigated the prevalence, phenotype and trafficking property of Th17 cells in patients with cervical cancer. Our results showed that Th17 cells highly aggregated within tumor tissues in an activated phenotype with markedly increased expression of CCR6. Correspondingly, level of CCL20 in the tumor tissues was significantly higher than that in non-tumor and normal control tissues, and strongly positively associated with Th17 cells. Further, in vitro migration assay showed CCL20 had effective chemotaxis to circulating Th17 cells. In conclusion, Th17 cells are recruited into tumor tissues preferentially through CCR6-CCL20 pathway, which can serve as a novel therapeutic target for cervical cancer.

  5. Cultured Mesenchymal Stem Cells Stimulate an Immune Response by Providing Immune Cells with Toll-Like Receptor 2 Ligand.

    Science.gov (United States)

    Weinstock, Ada; Pevsner-Fischer, Meirav; Porat, Ziv; Selitrennik, Michael; Zipori, Dov

    2015-12-01

    Mesenchymal stem cells (MSCs) serve as supporting and regulatory cells, by providing tissues with multiple factors and are also known for their immunosuppressive capabilities. Our laboratory had previously shown that MSCs expressed toll-like receptor (TLR) 2 and are activated by its ligand Pam3Cys. TLR2 is an important component of the innate immune system, as it recognizes bacterial lipopeptides, thus priming a pro-inflammatory immune response. This study showed that Pam3Cys attached extensively to cells of both wild-type and TLR2 deficient cultured MSCs, thus, independently of TLR2. The TLR2 independent binding occurred through the adsorption of the palmitoyl moieties of Pam3Cys. It was further showed that Pam3Cys was transferred from cultured MSCs to immune cells. Moreover, Pam3Cys provided to the immune cells induced a pro-inflammatory response in vitro and in vivo. Overall, it is demonstrated herein that a TLR2 ligand bound to MSCs also through a TLR2 independent mechanism. Furthermore, the ligand incorporated by MSCs is subsequently released to stimulate an immune response both in vitro and in vivo. It is thus suggested that during bacterial infection, stromal cells may retain a reservoir of the TLR2 ligands, in a long-term manner, and release them slowly to maintain an immune response.

  6. Recruitment of bone marrow CD11b+Gr-1+ cells by polymeric nanoparticles for antigen cross-presentation

    Science.gov (United States)

    Yang, Ya-Wun; Luo, Wen-Hui

    2017-03-01

    The objective of this study was to investigate the function of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) on the activation of antigen-specific CD8+ T cell responses via the CD11b+Gr-1+ myeloid subpopulations in murine bone marrow (BM). PLGA NPs containing ovalbumin (OVA) were fabricated by the double-emulsion method. The CD11b+Gr-1lowLy-6Chigh and CD11b+Gr-1highLy-6Clow subsets from mice bone marrow were sorted and treated with the PLGA/OVA NPs, followed by co-culture with the carboxyfluorescein succinimidyl ester (CFSE)-labelled OT-I CD8+ cells. Co-culture of OT-I CD8+ T cells with PLGA/OVA NPs-primed CD11b+Gr-1+ subsets upregulated the expression of IL-2, TNF-α, INF-γ, granzyme B, and perforin, resulting in proliferation of CD8+ T cells and differentiation into effector cytotoxic T lymphocytes (CTLs). In vivo proliferation of CFSE-labelled OT-I CD8+ cells in response to OVA was also obtained in the animals immunized with PLGA/OVA NPs. The results presented in this study demonstrate the ability of polymeric NPs to recruit two CD11b+Gr-1+ myeloid subsets for effective presentation of exogenous antigen to OT-I CD8+ T cells in the context of major histocompatibility complex (MHC) class I, leading to an induction of antigen-specific cell proliferation and differentiation into effector cells.

  7. Immune Monitoring Using mRNA-Transfected Dendritic Cells

    DEFF Research Database (Denmark)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by m......RNA electroporation, ensuring presentation of antigen through major histocompatibility complex I and potentially activating T cells, enabling them to kill the tumor cells. Despite extensive research in the field, only one dendritic cell-based vaccine has been approved. There is therefore a great need to elucidate...... and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA....

  8. Mycobacterium ulcerans Triggers T-Cell Immunity followed by Local and Regional but Not Systemic Immunosuppression▿

    Science.gov (United States)

    Fraga, Alexandra G.; Cruz, Andrea; Martins, Teresa G.; Torrado, Egídio; Saraiva, Margarida; Pereira, Daniela R.; Meyers, Wayne M.; Portaels, Françoise; Silva, Manuel T.; Castro, António G.; Pedrosa, Jorge

    2011-01-01

    Buruli ulcer is a neglected infectious disease caused by Mycobacterium ulcerans and is characterized by necrotic cutaneous lesions induced by the exotoxin mycolactone. Despite evidence of Th1-mediated protective immunity, M. ulcerans infection has been associated with systemic immunosuppression. We show that early during mouse infection with either mycolactone-positive or negative strains, pathogen-specific gamma interferon (IFN-γ)-producing T cells developed in the draining lymph node (DLN). CD4+ cells migrated to the infection foci, but progressive infection with virulent M. ulcerans led to the local depletion of recruited cells. Moreover, dissemination of virulent M. ulcerans to the DLN was accompanied by extensive DLN apoptotic cytopathology, leading to depletion of CD4+ T cells and abrogation of IFN-γ expression. Advanced footpad infection with virulent M. ulcerans did not induce increased susceptibility to systemic coinfection by Listeria monocytogenes. These results show that infection with M. ulcerans efficiently triggers a mycobacterium-specific T-cell response in the DLN and that progression of infection with highly virulent M. ulcerans leads to a local and regional suppression of that immune response, but without induction of systemic immunosuppression. These results suggest that prophylactic and/or therapeutic interventions to prevent dissemination of M. ulcerans to DLN during the early phase of infection would contribute for the maintenance of protective immunity and disease control. PMID:20974825

  9. Cell death programs in Yersinia immunity and pathogenesis.

    Science.gov (United States)

    Philip, Naomi H; Brodsky, Igor E

    2012-01-01

    Cell death plays a central role in host-pathogen interactions, as it can eliminate the pathogen's replicative niche and provide pro-inflammatory signals necessary for an effective immune response; conversely, cell death can allow pathogens to eliminate immune cells and evade anti-microbial effector mechanisms. In response to developmental signals or cell-intrinsic stresses, the executioner caspases-3 and -7 mediate apoptotic cell death, which is generally viewed as immunologically silent or immunosuppressive. A proinflammatory form of cell death that requires caspase-1, termed pyroptosis, is activated in response to microbial products within the host cytosol or disruption of cellular membranes by microbial pathogens. Infection by the bacterial pathogen Yersinia has features of both apoptosis and pyroptosis. Cell death and caspase-1 processing in Yersinia-infected cells occur in response to inhibition of NF-κB and MAPK signaling by the Yersinia virulence factor YopJ. However, the molecular basis of YopJ-induced cell death, and the role of different death pathways in anti-Yersinia immune responses remain enigmatic. Here, we discuss the role that cell death may play in inducing specific pro-inflammatory signals that shape innate and adaptive immune responses against Yersinia infection.

  10. Barrier Epithelial Cells and the Control of Type 2 Immunity.

    Science.gov (United States)

    Hammad, Hamida; Lambrecht, Bart N

    2015-07-21

    Type-2-cell-mediated immunity, rich in eosinophils, basophils, mast cells, CD4(+) T helper 2 (Th2) cells, and type 2 innate lymphoid cells (ILC2s), protects the host from helminth infection but also drives chronic allergic diseases like asthma and atopic dermatitis. Barrier epithelial cells (ECs) represent the very first line of defense and express pattern recognition receptors to recognize type-2-cell-mediated immune insults like proteolytic allergens or helminths. These ECs mount a prototypical response made up of chemokines, innate cytokines such as interleukin-1 (IL-1), IL-25, IL-33, and thymic stromal lymphopoietin (TSLP), as well as the alarmins uric acid, ATP, HMGB1, and S100 proteins. These signals program dendritic cells (DCs) to mount Th2-cell-mediated immunity and in so doing boost ILC2, basophil, and mast cell function. Here we review the general mechanisms of how different stimuli trigger type-2-cell-mediated immunity at mucosal barriers and how this leads to protection or disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Immunization with Bacillus Calmette-Guérin (BCG) alleviates neuroinflammation and cognitive deficits in APP/PS1 mice via the recruitment of inflammation-resolving monocytes to the brain.

    Science.gov (United States)

    Zuo, Zejie; Qi, Fangfang; Yang, Junhua; Wang, Xiao; Wu, Yingying; Wen, Yaru; Yuan, Qunfang; Zou, Juntao; Guo, Kaihua; Yao, Zhi Bin

    2017-05-01

    The immune system plays a crucial role in the progression of Alzheimer's disease (AD). Recently, immune-dependent cascade induced by systemic immune activation has been verified to play a beneficial role in AD mouse models. Here, we tested whether Bacillus Calmette-Guérin (BCG) immunization alters AD pathology and cognitive dysfunction in APP/PS1 AD mouse model, and with 4Aβ1-15 vaccination as positive control. It was found that BCG treatment reversed the cognitive decline to the extent observed in 4Aβ1-15 group, but did not reduce the β-amyloid (Aβ) burden in the brain. Then, we demonstrated the enhanced recruitment of inflammation-resolving monocytes across the choroid plexus and perivascular spaces to cerebral sites of plaque pathology in APP/PS1 mice immunized with BCG. Furthermore, elevated splenocyte Foxp3(+) regulatory T cell levels in the control APP/PS1 mice were down-regulated back to the wild-type (WT) levels by BCG treatment but not 4Aβ1-15 vaccination. In addition, BCG treatment induced the production of more circulating interferon (IFN)-γ than the controls and 4Aβ1-15 vaccination. Though the similar reductions in brain levels of pro-inflammatory cytokines were observed in the BCG and 4Aβ1-15 groups compared to the controls, only BCG had the great effect in upregulating cerebral anti-inflammatory cytokine levels as well as elevating the expression of neurotrophic factors in the brain of APP/PS1 mice. Thus, it is suggested that BCG exerts a beneficial immunomodulatory effect in APP/PS1 mice through mitigation of systemic immune suppression, induction of IFN-γ response and alleviation of the neuroinflammatory response.

  12. Recruitment of hypothalamic orexin neurons after formalin injections in adult male rats exposed to a neonatal immune challenge

    Directory of Open Access Journals (Sweden)

    Erin Jane Campbell

    2015-03-01

    Full Text Available Exposure to early life physiological stressors, such as infection, is thought to contribute to the onset of psychopathology in adulthood. In animal models, injections of the bacterial immune challenge, lipopolysaccharide (LPS, during the neonatal period has been shown to alter both neuroendocrine function and behavioural pain responses in adulthood. Interestingly, recent evidence suggests a role for the lateral hypothalamic peptide orexin in stress and nociceptive processing. However, whether neonatal LPS exposure affects the reactivity of the orexin system to formalin-induced inflammatory pain in later life remains to be determined. Male Wistar rats (n=13 were exposed to either LPS or saline (0.05mg/kg, i.p on postnatal days (PND 3 and 5. On PND 80-97, all rats were exposed to a subcutaneous hindpaw injection of 2.25% formalin. Following behavioural testing, animals were perfused and brains processed for Fos-protein and orexin immunohistochemistry. Rats treated with LPS during the neonatal period exhibited decreased licking behaviours during the interphase of the formalin test, the period typically associated with the active inhibition of pain, and increased grooming responses to formalin in adulthood. Interestingly, these behavioural changes were accompanied by an increase in the percentage of Fos-positive orexin cells in the dorsomedial and perifornical hypothalamus in LPS-exposed animals. Similar increases in Fos-protein were also observed in stress and pain sensitive brain regions that receive orexinergic inputs. These findings highlight a potential role for orexin in the behavioural responses to pain and provide further evidence that early life stress can prime the circuitry responsible for these responses in adulthood.

  13. In situ regeneration of skeletal muscle tissue through host cell recruitment.

    Science.gov (United States)

    Ju, Young Min; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2014-10-01

    Standard reconstructive procedures for restoring normal function after skeletal muscle defects involve the use of existing host tissues such as muscular flaps. In many instances, this approach is not feasible and delays the rehabilitation process and restoration of tissue function. Currently, cell-based tissue engineering strategies have been used for reconstruction; however, donor tissue biopsy and ex vivo cell manipulation are required prior to implantation. The present study aimed to overcome these limitations by demonstrating mobilization of muscle cells into a target-specific site for in situ muscle regeneration. First, we investigated whether host muscle cells could be mobilized into an implanted scaffold. Poly(l-lactic acid) (PLLA) scaffolds were implanted in the tibialis anterior (TA) muscle of rats, and the retrieved scaffolds were characterized by examining host cell infiltration in the scaffolds. The host cell infiltrates, including Pax7+ cells, gradually increased with time. Second, we demonstrated that host muscle cells could be enriched by a myogenic factor released from the scaffolds. Gelatin-based scaffolds containing a myogenic factor were implanted in the TA muscle of rats, and the Pax7+ cell infiltration and newly formed muscle fibers were examined. By the second week after implantation, the Pax7+ cell infiltrates and muscle formation were significantly accelerated within the scaffolds containing insulin-like growth factor 1 (IGF-1). Our data suggest an ability of host stem cells to be recruited into the scaffolds with the capability of differentiating to muscle cells. In addition, the myogenic factor effectively promoted host cell recruitment, which resulted in accelerating muscle regeneration in situ.

  14. Tailored immune responses: novel effector helper T cell subsets in protective immunity.

    Directory of Open Access Journals (Sweden)

    Ervin E Kara

    2014-02-01

    Full Text Available Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H1/T(H2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

  15. Tailored immune responses: novel effector helper T cell subsets in protective immunity.

    Science.gov (United States)

    Kara, Ervin E; Comerford, Iain; Fenix, Kevin A; Bastow, Cameron R; Gregor, Carly E; McKenzie, Duncan R; McColl, Shaun R

    2014-02-01

    Differentiation of naïve CD4⁺ cells into functionally distinct effector helper T cell subsets, characterised by distinct "cytokine signatures," is a cardinal strategy employed by the mammalian immune system to efficiently deal with the rapidly evolving array of pathogenic microorganisms encountered by the host. Since the T(H)1/T(H)2 paradigm was first described by Mosmann and Coffman, research in the field of helper T cell biology has grown exponentially with seven functionally unique subsets having now been described. In this review, recent insights into the molecular mechanisms that govern differentiation and function of effector helper T cell subsets will be discussed in the context of microbial infections, with a focus on how these different helper T cell subsets orchestrate immune responses tailored to combat the nature of the pathogenic threat encountered.

  16. Splicing in immune cells-mechanistic insights and emerging topics.

    Science.gov (United States)

    Schaub, Annalisa; Glasmacher, Elke

    2017-04-01

    Differential splicing of mRNAs not only enables regulation of gene expression levels, but also ensures a high degree of gene-product diversity. The extent to which splicing of mRNAs is utilized as a mechanism in immune cells has become evident within the last few years. Still, only a few of these mechanisms have been well studied. In this review, we discuss some of the best-understood mechanisms, for instance the differential splicing of CD45 in T cells, as well as immunoglobulin genes in B cells. Beyond that we provide general mechanistic insights on how, when and where this process takes place and discuss the current knowledge regarding these topics in immune cells. We also highlight some of the reported links to immune-related diseases, genome-wide sequencing studies that revealed thousands of differentially spliced transcripts, as well as splicing studies on immune cells that remain mechanistically not fully understood. We thereby display potential emerging topics for future studies centered on splicing mechanisms in immune cells. © The Author 2017. Published by Oxford University Press on behalf of The Japanese Society for Immunology.

  17. Effect of pemetrexed on innate immune killer cells and adaptive immune T cells in subjects with adenocarcinoma of the pancreas.

    Science.gov (United States)

    Davis, Marcherie; Conlon, Kevin; Bohac, Gerald C; Barcenas, John; Leslie, William; Watkins, LaTanja; Lamzabi, Ihab; Deng, Youping; Li, Yan; Plate, Janet M D

    2012-10-01

    Baseline levels of innate and adaptive immune cell functions were studied in patients with pancreatic cancer. The effects of pemetrexed were measured at 7 and 14 days after initial therapy then 14 days after combination therapy with gemcitabine. Pretherapy levels of absolute numbers of natural killer (NK) cells positively correlated with survival. Cytolytic units of NK activity correlated positively with NK cell numbers. Pemetrexed decreased NK cytolytic units to significance when combined with gemcitabine. Pemetrexed increased intracellular accumulation of interferon gamma (IFNγ) in NK cells that correlated negatively with survival. Addition of gemcitabine decreased IFNγ-producing NK cells to baseline. Memory (CD45RO*) T cells enumerated at baseline correlated negatively with survival but were decreased by pemetrexed therapy. Memory T cells were increased in subjects with greater B7-H3 expression in tumor tissue, whereas OX40*-activated total T cells and helper T-cell subset were decreased. FoxP3*, CD8* T cells correlated positively with progression-free interval and survival. In conclusion, innate NK-cell immunity and FoxP3*, CD8* T cells seemed beneficial to pancreatic cancer patients. Higher levels of B7-H3 expression in pancreatic tumors were detrimental to effective immunity. Although pemetrexed therapy increased activation of a subset of NK cells to produce IFNγ, addition of gemcitabine abated those responses, decreasing IFNγ-producing NK cells, whereas NK cells producing interleukin-2 without IFNγ at this timepoint positively correlated with survival. Innate immunity and adaptive immunity thus are important in defense against pancreatic cancer. Progression-free interval and survival were longer than observed in a phase III trial where gemcitabine preceded pemetrexed suggesting that a larger trial of pemetrexed preceding gemcitabine is warranted.

  18. Recruitment of Factor H to the Streptococcus suis Cell Surface is Multifactorial

    Directory of Open Access Journals (Sweden)

    David Roy

    2016-07-01

    Full Text Available Streptococcus suis is an important bacterial swine pathogen and a zoonotic agent. Recently, two surface proteins of S. suis, Fhb and Fhbp, have been described for their capacity to bind factor H—a soluble complement regulatory protein that protects host cells from complement-mediated damages. Results obtained in this study showed an important role of host factor H in the adhesion of S. suis to epithelial and endothelial cells. Both Fhb and Fhbp play, to a certain extent, a role in such increased factor H-dependent adhesion. The capsular polysaccharide (CPS of S. suis, independently of the presence of its sialic acid moiety, was also shown to be involved in the recruitment of factor H. However, a triple mutant lacking Fhb, Fhbp and CPS was still able to recruit factor H resulting in the degradation of C3b in the presence of factor I. In the presence of complement factors, the double mutant lacking Fhb and Fhbp was similarly phagocytosed by human macrophages and killed by pig blood when compared to the wild-type strain. In conclusion, this study suggests that recruitment of factor H to the S. suis cell surface is multifactorial and redundant.

  19. Recruitment of Factor H to the Streptococcus suis Cell Surface is Multifactorial.

    Science.gov (United States)

    Roy, David; Grenier, Daniel; Segura, Mariela; Mathieu-Denoncourt, Annabelle; Gottschalk, Marcelo

    2016-07-07

    Streptococcus suis is an important bacterial swine pathogen and a zoonotic agent. Recently, two surface proteins of S. suis, Fhb and Fhbp, have been described for their capacity to bind factor H-a soluble complement regulatory protein that protects host cells from complement-mediated damages. Results obtained in this study showed an important role of host factor H in the adhesion of S. suis to epithelial and endothelial cells. Both Fhb and Fhbp play, to a certain extent, a role in such increased factor H-dependent adhesion. The capsular polysaccharide (CPS) of S. suis, independently of the presence of its sialic acid moiety, was also shown to be involved in the recruitment of factor H. However, a triple mutant lacking Fhb, Fhbp and CPS was still able to recruit factor H resulting in the degradation of C3b in the presence of factor I. In the presence of complement factors, the double mutant lacking Fhb and Fhbp was similarly phagocytosed by human macrophages and killed by pig blood when compared to the wild-type strain. In conclusion, this study suggests that recruitment of factor H to the S. suis cell surface is multifactorial and redundant.

  20. Biphasic recruitment of microchimeric fetal mesenchymal cells in fibrosis following acute kidney injury.

    Science.gov (United States)

    Roy, Edwige; Seppanen, Elke; Ellis, Rebecca; Lee, Eddy S; Khosrotehrani, Kiarash; Khosroterani, Kiarash; Fisk, Nicholas M; Bou-Gharios, George

    2014-03-01

    Fetal microchimeric cells (FMCs) enter the maternal circulation and persist in tissue for decades. They have capacity to home to injured maternal tissue and differentiate along that tissue's lineage. This raises the question of the origin(s) of cells transferred to the mother during pregnancy. FMCs with a mesenchymal phenotype have been documented in several studies, which makes mesenchymal stem cells an attractive explanation for their broad plasticity. Here we assessed the recruitment and mesenchymal lineage contribution of FMCs in response to acute kidney fibrosis induced by aristolochic acid injection. Serial in vivo bioluminescence imaging revealed a biphasic recruitment of active collagen-producing FMCs during the repair process of injured kidney in post-partum wild-type mothers that had delivered transgenic pups expressing luciferase under the collagen type I-promoter. The presence of FMCs long-term post injury (day 60) was associated with profibrotic molecules (TGF-β/CTGF), serum urea levels, and collagen deposition. Immunostaining confirmed FMCs at short term (day 15) using post-partum wild-type mothers that had delivered green fluorescent protein-positive pups and suggested a mainly hematopoietic phenotype. We conclude that there is biphasic recruitment to, and activity of, FMCs at the injury site. Moreover, we identified five types of FMC, implicating them all in the reparative process at different stages of induced renal interstitial fibrosis.

  1. Sonic hedgehog mediates the proliferation and recruitment of transformed mesenchymal stem cells to the stomach.

    Directory of Open Access Journals (Sweden)

    Jessica M Donnelly

    Full Text Available Studies using Helicobacter-infected mice show that bone marrow-derived mesenchymal stem cells (MSCs can repopulate the gastric epithelium and promote gastric cancer progression. Within the tumor microenvironment of the stomach, pro-inflammatory cytokine interferon-gamma (IFNγ and Sonic hedgehog (Shh are elevated. IFNγ is implicated in tumor proliferation via activation of the Shh signaling pathway in various tissues but whether a similar mechanism exists in the stomach is unknown. We tested the hypothesis that IFNγ drives MSC proliferation and recruitment, a response mediated by Shh signaling. The current study uses transplantation of an in vitro transformed mesenchymal stem cell line (stMSC(vect, that over-expresses hedgehog signaling, in comparison to non-transformed wild-type MSCs (wtMSCs, wtMSCs transfected to over-express Shh (wtMSC(Shh, and stMSCs transduced with lentiviral constructs containing shRNA targeting the Shh gene (stMSC(ShhKO. The effect of IFNγ on MSC proliferation was assessed by cell cycle analysis in vitro using cells treated with recombinant IFNγ (rmIFNγ alone, or in combination with anti-Shh 5E1 antibody, and in vivo using mice transplanted with MSCs treated with PBS or rmIFNγ. In vitro, IFNγ significantly increased MSC proliferation, a response mediated by Shh that was blocked by 5E1 antibody. The MSC population collected from bone marrow of PBS- or IFNγ-treated mice showed that IFNγ significantly increased the percentage of all MSC cell lines in S phase, with the exception of the stMSCs(ShhKO cells. While the MSC cell lines with intact Shh expression were recruited to the gastric mucosa in response to IFNγ, stMSCs(ShhKO were not. Hedgehog signaling is required for MSC proliferation and recruitment to the stomach in response to IFNγ.

  2. Host Cell Autophagy in Immune Response to Zoonotic Infections

    Directory of Open Access Journals (Sweden)

    Panagiotis Skendros

    2012-01-01

    Full Text Available Autophagy is a fundamental homeostatic process in which cytoplasmic targets are sequestered within double-membraned autophagosomes and subsequently delivered to lysosomes for degradation. Accumulating evidence supports the pivotal role of autophagy in host defense against intracellular pathogens implicating both innate and adaptive immunity. Many of these pathogens cause common zoonotic infections worldwide. The induction of the autophagic machinery by innate immune receptors signaling, such as TLRs, NOD1/2, and p62/SQSTM1 in antigen-presenting cells results in inhibition of survival and elimination of invading pathogens. Furthermore, Th1 cytokines induce the autophagic process, whereas autophagy also contributes to antigen processing and MHC class II presentation, linking innate to adaptive immunity. However, several pathogens have developed strategies to avoid autophagy or exploit autophagic machinery to their advantage. This paper focuses on the role of host cell autophagy in the regulation of immune response against intracellular pathogens, emphasizing on selected bacterial and protozoan zoonoses.

  3. Spaceflight alters immune cell function and distribution

    Science.gov (United States)

    Sonnenfeld, Gerald; Mandel, Adrian D.; Konstantinova, Irina V.; Berry, Wallace D.; Taylor, Gerald R.; Lesniak, A. T.; Fuchs, Boris B.; Rakhmilevich, Alexander L.

    1992-01-01

    Experiments are described which were performed onboard Cosmos 2044 to determine spaceflight effects on immunologically important cell function and distribution. Results indicate that bone marrow cells from flown and suspended rats exhibited a decreased response to a granulocyte/monocyte colony-stimulating factor compared with the bone marrow cells from control rats. Bone marrow cells showed an increase in the percentage of cells expressing markers for helper T-cells in the myelogenous population and increased percentages of anti-asialo granulocyte/monocyte-1-bearing interleulin-2 receptor bearing pan T- and helper T-cells in the lymphocytic population.

  4. Peptide pool immunization and CD8+ T cell reactivity

    DEFF Research Database (Denmark)

    Rasmussen, Susanne B; Harndahl, Mikkel N; Buus, Anette Stryhn

    2013-01-01

    Mice were immunized twice with a pool of five peptides selected among twenty 8-9-mer peptides for their ability to form stable complexes at 37°C with recombinant H-2K(b) (half-lives 10-15h). Vaccine-induced immunity of splenic CD8(+) T cells was studied in a 24h IFNγ Elispot assay. Surprisingly......, IFNγ spot-formation was observed without addition of peptide to the assay culture at 3 weeks and 3 months after immunization. To clarify if IFNγ spot formation in the absence of peptide exposure ex vivo is caused by the peptide-pool per se, mice were immunized with single peptides. Three of the five...... peptides induced normal peptide immunity i.e. the specific T cell reactivity in the Elispot culture was strictly dependent on exposure to the immunizing peptide ex vivo. However, immunization with two of the peptides, a VSV- and a Mycobacterium-derived peptide, resulted in IFNγ spot formation without...

  5. Impact of sepsis on CD4 T cell immunity

    Science.gov (United States)

    Cabrera-Perez, Javier; Condotta, Stephanie A.; Badovinac, Vladimir P.; Griffith, Thomas S.

    2014-01-01

    Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state. PMID:24791959

  6. Mobilizing forces -CD4~+ helper T cells script adaptive immunity

    Institute of Scientific and Technical Information of China (English)

    Frédérick Masson; Gabrielle T Belz

    2010-01-01

    Traditionally, CD4~+ T cells have been understood to play a key role in 'helping' CD8~+ T cells undergo efficient activation and proliferation in response to foreign pathogens. This has been thought to be directed primarily by CD4~+ T cell interactions with dendritic cells (DCs) [1, 2] that convert 'unlicenced' DCs into DCs capable of implementing a full blown immune response ('licenced' DCs).

  7. Integrin-independent movement of immune cells

    OpenAIRE

    Pinner, Sophie E; Sahai, Erik

    2009-01-01

    Cell motility requires the temporal and spatial coordination of the actin cytoskeleton with cell-matrix adhesions. Since their discovery more than 20 years ago, integrins have been at the center of cell-matrix adhesion research. Integrin-mediated adhesions link the actin network to the extracellular matrix and are commonly observed as cells migrate across rigid two-dimensional substrates. However, as more cell motility studies are being conducted in three-dimensional (3D) culture systems and ...

  8. Hepatic stellate cells and innate immunity in alcoholic liver disease

    Institute of Scientific and Technical Information of China (English)

    Yang-Gun Suh; Won-Il Jeong

    2011-01-01

    Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

  9. Interactions between the immune and nervous systems in pain

    OpenAIRE

    Ren,Ke; Dubner, Ronald

    2010-01-01

    Immune cells and glia interact with neurons to alter pain sensitivity and to mediate the transition from acute to chronic pain. In response to injury, resident immune cells are activated and blood-borne immune cells are recruited to the site of injury. Immune cells not only contribute to immune protection but also initiate the sensitization of peripheral nociceptors. Through the synthesis and release of inflammatory mediators and interactions with neurotransmitters and their receptors, the im...

  10. Recruitment of bone marrow derived cells during anti-angiogenic therapy in GBM : Bone marrow derived cell in GBM

    NARCIS (Netherlands)

    Boer, Jennifer C.; Walenkamp, Annemiek M. E.; den Dunnen, Wilfred F. A.

    2014-01-01

    Glioblastoma (GBM) is a highly vascular tumor characterized by rapid and invasive tumor growth, followed by oxygen depletion, hypoxia and neovascularization, which generate a network of disorganized, tortuous and permeable vessels. Recruitment of bone marrow derived cells (BMDC) is crucial for vascu

  11. Alemtuzumab treatment alters circulating innate immune cells in multiple sclerosis

    Science.gov (United States)

    Ahmetspahic, Diana; Ruck, Tobias; Schulte-Mecklenbeck, Andreas; Schwarte, Kathrin; Jörgens, Silke; Scheu, Stefanie; Windhagen, Susanne; Graefe, Bettina; Melzer, Nico; Klotz, Luisa; Arolt, Volker; Wiendl, Heinz; Meuth, Sven G.

    2016-01-01

    Objective: To characterize changes in myeloid and lymphoid innate immune cells in patients with relapsing-remitting multiple sclerosis (MS) during a 6-month follow-up after alemtuzumab treatment. Methods: Circulating innate immune cells including myeloid cells and innate lymphoid cells (ILCs) were analyzed before and 6 and 12 months after onset of alemtuzumab treatment. Furthermore, a potential effect on granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)–23 production by myeloid cells and natural killer (NK) cell cytolytic activity was determined. Results: In comparison to CD4+ T lymphocytes, myeloid and lymphoid innate cell subsets of patients with MS expressed significantly lower amounts of CD52 on their cell surface. Six months after CD52 depletion, numbers of circulating plasmacytoid dendritic cells (DCs) and conventional DCs were reduced compared to baseline. GM-CSF and IL-23 production in DCs remained unchanged. Within the ILC compartment, the subset of CD56bright NK cells specifically expanded under alemtuzumab treatment, but their cytolytic activity did not change. Conclusions: Our findings demonstrate that 6 months after alemtuzumab treatment, specific DC subsets are reduced, while CD56bright NK cells expanded in patients with MS. Thus, alemtuzumab specifically restricts the DC compartment and expands the CD56bright NK cell subset with potential immunoregulatory properties in MS. We suggest that remodeling of the innate immune compartment may promote long-term efficacy of alemtuzumab and preserve immunocompetence in patients with MS. PMID:27766281

  12. "Flagellated" cancer cells propel anti-tumor immunity.

    Science.gov (United States)

    Garaude, Johan; Blander, J Magarian

    2012-09-01

    The use of innate immune receptor agonists in cancer therapies has suffered from many drawbacks. Our recent observations suggest that some of these hurdles can be overcome by introducing flagellin into tumor cells to promote tumor antigen presentation by dendritic cells (DCs) and simultaneously trigger two types of pattern recognition receptors (PRRs).

  13. The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots.

    Directory of Open Access Journals (Sweden)

    Nicholas Holton

    2015-01-01

    Full Text Available During plant immunity, surface-localized pattern recognition receptors (PRRs recognize pathogen-associated molecular patterns (PAMPs. The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs EFR and XA21 from Arabidopsis thaliana (Arabidopsis and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots.

  14. Neutrophils are dispensable in the modulation of T cell immunity against cutaneous HSV-1 infection

    Science.gov (United States)

    Hor, Jyh Liang; Heath, William R.; Mueller, Scott N.

    2017-01-01

    Neutrophils rapidly infiltrate sites of inflammation during peripheral infection or tissue injury. In addition to their well described roles as pro-inflammatory phagocytes responsible for pathogen clearance, recent studies have demonstrated a broader functional repertoire including mediating crosstalk between innate and adaptive arms of the immune system. Specifically, neutrophils have been proposed to mediate antigen transport to lymph nodes (LN) to modulate T cell priming and to influence T cell migration to infected tissues. Using a mouse model of cutaneous herpes simplex virus type 1 (HSV-1) infection we explored potential contributions of neutrophils toward anti-viral immunity. While a transient, early influx of neutrophils was triggered by dermal scarification, we did not detect migration of neutrophils from the skin to LN. Furthermore, despite recruitment of neutrophils into LN from the blood, priming and expansion of CD4+ and CD8+ T cells was unaffected following neutrophil depletion. Finally, we found that neutrophils were dispensable for the migration of effector T cells into infected skin. Our study suggests that the immunomodulatory roles of neutrophils toward adaptive immunity may be context-dependent, and are likely determined by the type of pathogen and anatomical site of infection. PMID:28112242

  15. IDO expression in brain tumors increases the recruitment of regulatory T cells and negatively impacts survival.

    Science.gov (United States)

    Wainwright, Derek A; Balyasnikova, Irina V; Chang, Alan L; Ahmed, Atique U; Moon, Kyung-Sub; Auffinger, Brenda; Tobias, Alex L; Han, Yu; Lesniak, Maciej S

    2012-11-15

    Glioblastoma multiforme (GBM) is an aggressive adult brain tumor with a poor prognosis. One hallmark of GBM is the accumulation of immunosuppressive and tumor-promoting CD4(+)FoxP3(+)GITR(+) regulatory T cells (Tregs). Here, we investigated the role of indoleamine 2,3 dioxygenase (IDO) in brain tumors and the impact on Treg recruitment. To determine the clinical relevance of IDO expression in brain tumors, we first correlated patient survival to the level of IDO expression from resected glioma specimens. We also used novel orthotopic and transgenic models of glioma to study how IDO affects Tregs. The impact of tumor-derived and peripheral IDO expression on Treg recruitment, GITR expression, and long-term survival was determined. Downregulated IDO expression in glioma predicted a significantly better prognosis in patients. Coincidently, both IDO-competent and deficient mice showed a survival advantage bearing IDO-deficient brain tumors, when compared with IDO-competent brain tumors. Moreover, IDO deficiency was associated with a significant decrease in brain-resident Tregs, both in orthotopic and transgenic mouse glioma models. IDO deficiency was also associated with lower GITR expression levels on Tregs. Interestingly, the long-term survival advantage conferred by IDO deficiency was lost in T-cell-deficient mice. These clinical and preclinical data confirm that IDO expression increases the recruitment of immunosuppressive Tregs that lead to tumor outgrowth. In contrast, IDO deficiency decreases Treg recruitment and enhances T-cell-mediated tumor rejection. Thus, the data suggest a critical role for IDO-mediated immunosuppression in glioma and support the continued investigation of IDO-Treg interactions in the context of brain tumors. ©2012 AACR.

  16. Marginal zone B-cells, a gatekeeper of innate immunity.

    Science.gov (United States)

    Zouali, Moncef; Richard, Yolande

    2011-01-01

    To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B lymphocytes were initially thought to only play a role in the adaptive branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ) and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount a local antibody response against type-2 T-cell-independent (TI-2) antigens, MZ B-cells can participate to T-cell-dependent (TD) immune responses through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in humans, non-human primates, and rodents. We also summarize studies - performed in transgenic mice expressing fully human antibodies on their B-cells and in macaques whose infection with Simian immunodeficiency virus (SIV) represents a suitable model for HIV-1 infection in humans - showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus) as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells - MZ B-cells and/or B1 B-cells - with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies.

  17. Effects of spaceflight on levels and activity of immune cells

    Science.gov (United States)

    Sonnenfeld, Gerald; Berry, Wallace D.; Mandel, Adrian D.; Konstantinova, Irena V.; Taylor, Gerald R.

    1990-01-01

    Experiments were carried out on cells from rats that had been flown on Soviet Biosputnik Cosmos 1887 to explore the effects of speceflight on immune responses. Rat bone marrow cells were examined for their response to colony stimulating factor-M. Rat spleen and bone marrow cells were stained with antibodies directed against cell surface antigenic markers. The results of the studies indicate that bone marrow cells from flown rats showed a decreased response to colony stimulating factor. There was a higher percentage of spleen cells from flown rats staining positively for pan-T-cell, suppressor-T-cell, and interleukin-2 receptor cell surface antigens. A small increase in the percentage of cells staining positively for helper-T-cell antigens was also noted. In addition, a higher percentage of cells that appeared to be part of the myelogenous population of bone marrow cells from flown rats stained positively for surface immunoglobulin.

  18. Regulation of the human cathelicidin antimicrobial peptide gene by 1α,25-dihydroxyvitamin D3 in primary immune cells

    DEFF Research Database (Denmark)

    Lowry, Malcolm B; Guo, Chunxiao; Borregaard, Niels;

    2014-01-01

    Production of the human cathelicidin antimicrobial peptide gene (hCAP18/LL-37), is regulated by 1α,25-dihydroxyvitamin D3 (1,25D3) and is critical in the killing of pathogens by innate immune cells. In addition, secreted LL-37 binds extracellular receptors and modulates the recruitment and activity...... of both innate and adaptive immune cells. Evidence suggests that during infections activated immune cells locally produce increased levels of 1,25D3 thus increasing production of hCAP18/LL-37. The relative expression levels of hCAP18/LL-37 among different immune cell types are not well characterized....... The aim of this study was to determine the relative levels of hCAP18/LL-37 in human peripheral blood immune cells and determine to what extent 1,25D3 increased its expression in peripheral blood-derived cells. We show for the first time, a hierarchy of expression of hCAP18 in freshly isolated cells...

  19. B cells as a target of immune modulation

    Directory of Open Access Journals (Sweden)

    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  20. Th9 Cells Drive Host Immunity against Gastrointestinal Worm Infection.

    Science.gov (United States)

    Licona-Limón, Paula; Henao-Mejia, Jorge; Temann, Angela U; Gagliani, Nicola; Licona-Limón, Ileana; Ishigame, Harumichi; Hao, Liming; Herbert, De'broski R; Flavell, Richard A

    2013-10-17

    Type 2 inflammatory cytokines, including interleukin-4 (IL-4), IL-5, IL-9, and IL-13, drive the characteristic features of immunity against parasitic worms and allergens. Whether IL-9 serves an essential role in the initiation of host-protective responses is controversial, and the importance of IL-9- versus IL-4-producing CD4⁺ effector T cells in type 2 immunity is incompletely defined. Herein, we generated IL-9-deficient and IL-9-fluorescent reporter mice that demonstrated an essential role for this cytokine in the early type 2 immunity against Nippostrongylus brasiliensis. Whereas T helper 9 (Th9) cells and type 2 innate lymphoid cells (ILC2s) were major sources of infection-induced IL-9 production, the adoptive transfer of Th9 cells, but not Th2 cells, caused rapid worm expulsion, marked basophilia, and increased mast cell numbers in Rag2-deficient hosts. Taken together, our data show a critical and nonredundant role for Th9 cells and IL-9 in host-protective type 2 immunity against parasitic worm infection. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Ongoing cell death and immune influences on regeneration in the vestibular sensory organs

    Science.gov (United States)

    Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.

    2001-01-01

    Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.

  2. Differential recruitment of Dishevelled provides signaling specificity in the planar cell polarity and Wingless signaling pathways.

    Science.gov (United States)

    Axelrod, J D; Miller, J R; Shulman, J M; Moon, R T; Perrimon, N

    1998-08-15

    In Drosophila, planar cell polarity (PCP) signaling is mediated by the receptor Frizzled (Fz) and transduced by Dishevelled (Dsh). Wingless (Wg) signaling also requires Dsh and may utilize DFz2 as a receptor. Using a heterologous system, we show that Dsh is recruited selectively to the membrane by Fz but not DFz2, and this recruitment depends on the DEP domain but not the PDZ domain in Dsh. A mutation in the DEP domain impairs both membrane localization and the function of Dsh in PCP signaling, indicating that translocation is important for function. Further genetic and molecular analyses suggest that conserved domains in Dsh function differently during PCP and Wg signaling, and that divergent intracellular pathways are activated. We propose that Dsh has distinct roles in PCP and Wg signaling. The PCP signal may selectively result in focal Fz activation and asymmetric relocalization of Dsh to the membrane, where Dsh effects cytoskeletal reorganization to orient prehair initiation.

  3. Plasmacytoid dendritic cells in antiviral immunity and autoimmunity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Plasmacytoid dendritic cells (pDCs) represent a unique and crucial immune cell population capable of producing large amounts of type I interferons (IFNs) in response to viral infection.The function of pDCs as the professional type I IFN-producing cells is linked to their selective expression of Toll-like receptor 7 (TLR7) and TLR9,which sense viral nucleic acids within the endosomal compartments.Type I IFNs produced by pDCs not only directly inhibit viral replication but also play an essential role in linking the innate and adaptive immune system.The aberrant activation of pDCs by self nucleic acids through TLR signaling and the ongoing production of type I IFNs do occur in some autoimmune diseases.Therefore,pDC may serve as an attractive target for therapeutic manipulations of the immune system to treat viral infectious diseases and autoimmune diseases.

  4. Ikaros can enhance immune activity though the interaction with Autotaxin in LDIR exposed immune cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Jin; Kim, Min Young; Kim, Ji Young; Kim, Hee Sun; KIm, Cha Soon; Nam, Seon Young; Yang, Kwang Hee; Jin, Young Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd, Seoul (Korea, Republic of)

    2009-04-15

    Ikaros, one of transcription factors, plays major roles in the differentiation and biology of leukocytes, including all classes of lymphocytes (NK, T, and B cells), monocytes/macrophages, and dendritic cells. Ikaros was also shown to regulate early neutrophils differentiation. Therefore, Ikaros appears to be a major determinant in the development and function of immune system. Autotaxin (ATX), which is also called nucleotide pyrophosphatase/phosphodiesterase 2 (NPP2), is an exo-enzyme originally identified as a tumor cell autocrine motility factor. ATX functions as a lysophospholipase D, converting lysophosphatidylcholine (LPC) into the lipid mediator lysophosphatidic acid (LPA). LPA bind together with specific G protein-coupled receptors, which elicit a wide range of cellular responses including the cell proliferation, migration and neurite remodeling. In the Recent report, ATX stimulate human endothelial cells (HUVECs) growth and cytokine production. In our previous study, we showed that low-dose ionizing radiation (LDIR) enhanced the cell proliferation cell coupled with Ikaros phosphorylation. In addition, we found that LDIR increased the expression level of cyclin E and cdk2 protein in IM-9 B lymphoblast cells. In this report, therefore, we try to find Ikaros binding proteins after LDIR in IM-9 lymphoblastic cell lines to examine whether the effects of LDIR induced cell proliferation are one of immune activation responses or not.

  5. Regulatory T cells reduce acute lung injury fibroproliferation by decreasing fibrocyte recruitment.

    Science.gov (United States)

    Garibaldi, Brian T; D'Alessio, Franco R; Mock, Jason R; Files, D Clark; Chau, Eric; Eto, Yoshiki; Drummond, M Bradley; Aggarwal, Neil R; Sidhaye, Venkataramana; King, Landon S

    2013-01-01

    Acute lung injury (ALI) causes significant morbidity and mortality. Fibroproliferation in ALI results in worse outcomes, but the mechanisms governing fibroproliferation remain poorly understood. Regulatory T cells (Tregs) are important in lung injury resolution. Their role in fibroproliferation is unknown. We sought to identify the role of Tregs in ALI fibroproliferation, using a murine model of lung injury. Wild-type (WT) and lymphocyte-deficient Rag-1(-/-) mice received intratracheal LPS. Fibroproliferation was characterized by histology and the measurement of lung collagen. Lung fibrocytes were measured by flow cytometry. To dissect the role of Tregs in fibroproliferation, Rag-1(-/-) mice received CD4(+)CD25(+) (Tregs) or CD4(+)CD25(-) Tcells (non-Tregs) at the time of LPS injury. To define the role of the chemokine (C-X-C motif) ligand 12 (CXCL12)-CXCR4 pathway in ALI fibroproliferation, Rag-1(-/-) mice were treated with the CXCR4 antagonist AMD3100 to block fibrocyte recruitment. WT and Rag-1(-/-) mice demonstrated significant collagen deposition on Day 3 after LPS. WT mice exhibited the clearance of collagen, but Rag-1(-/-) mice developed persistent fibrosis. This fibrosis was mediated by the sustained epithelial expression of CXCL12 (or stromal cell-derived factor 1 [SDF-1]) that led to increased fibrocyte recruitment. The adoptive transfer of Tregs resolved fibroproliferation by decreasing CXCL12 expression and subsequent fibrocyte recruitment. Blockade of the CXCL12-CXCR4 axis with AMD3100 also decreased lung fibrocytes and fibroproliferation. These results indicate a central role for Tregs in the resolution of ALI fibroproliferation by reducing fibrocyte recruitment along the CXCL12-CXCR4 axis. A dissection of the role of Tregs in ALI fibroproliferation may inform the design of new therapeutic tools for patients with ALI.

  6. Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Robert T. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); O' Brien, Fergal J. [Tissue Engineering Research Group, Dept. of Anatomy, Royal College of Surgeons in Ireland (Ireland); Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin & Royal College of Surgeons in Ireland (Ireland); Hoey, David A., E-mail: david.hoey@ul.ie [Trinity Centre for Bioengineering, School of Engineering, Trinity College Dublin (Ireland); Dept. of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); The Centre for Applied Biomedical Engineering Research, University of Limerick (Ireland); Materials & Surface Science Institute, University of Limerick (Ireland)

    2015-03-27

    Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors. - Highlights: • Physically stimulated osteocytes secrete factors that regulate osteoprogenitors. • These factors enhance recruitment, proliferation and osteogenic differentiation. • Physically stimulated osteoblasts secrete factors that also regulate progenitors. • These factors enhance recruitment but inhibit proliferation of osteoprogenitors. • This study highlights a contrasting

  7. EXPRESSION OF IMMUNE-RELATED MOLECULES IN GLIOBLASTOMA MULTIFORM CELLS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective: To investigate the expression of immune- related molecules in glioblastoma multiform(GBM) cells. Methods: The expression of major histocompatibility complex (MHC), β2-microglobulin, Fas, CD80 and CD86 molecules on the surface of GBM cells were evaluated by flow cytometry. The expression of TAP-1, TAP-2 and Tapasin in the GBM cells were evaluated by RT-PCR method. Results: MHC class Ⅰ, β2 microglobulin, TAP-1, TAP-2 and tapasin were expressed in most GBM cell lines. Except U87, there was no MHC class Ⅱ molecule expression on any of the other GBM cell lines. Fas was expressed on all the GBM cell lines examined. Conclusion: The mechanism by which GBM escapes immune surveillance may involve down regulation of expression of MHC class Ⅰ molecules and MHC class Ⅱ molecules. MHC class Ⅰpositive GBM may be the suitable target of immunotherapy.

  8. DMPD: Zinc in human health: effect of zinc on immune cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18385818 Zinc in human health: effect of zinc on immune cells. Prasad AS. Mol Med. ...2008 May-Jun;14(5-6):353-7. (.png) (.svg) (.html) (.csml) Show Zinc in human health: effect of zinc on immun...e cells. PubmedID 18385818 Title Zinc in human health: effect of zinc on immune cells. Authors Prasad AS. Pu

  9. Lipoxin A4 inhibits immune cell binding to salivary epithelium and vascular endothelium.

    Science.gov (United States)

    Chinthamani, Sreedevi; Odusanwo, Olutayo; Mondal, Nandini; Nelson, Joel; Neelamegham, Sriram; Baker, Olga J

    2012-04-01

    Lipoxins are formed by leukocytes during cell-cell interactions with epithelial or endothelial cells. Native lipoxin A(4) (LXA(4)) binds to the G protein-coupled lipoxin receptors formyl peptide receptor 2 (FPR2)/ALX and CysLT1. Furthermore, LXA(4) inhibits recruitment of neutrophils, by attenuating chemotaxis, adhesion, and transmigration across vascular endothelial cells. LXA(4) thus appears to serve as an endogenous "stop signal" for immune cell-mediated tissue injury (Serhan CN; Annu Rev Immunol 25: 101-137, 2007). The role of LXA(4) has not been addressed in salivary epithelium, and little is known about its effects on vascular endothelium. Here, we determined that interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) receptor activation in vascular endothelium and salivary epithelium upregulated the expression of adhesion molecules that facilitates the binding of immune cells. We hypothesize that the activation of the ALX/FPR2 and/or CysLT1 receptors by LXA(4) decreases this cytokine-mediated upregulation of cell adhesion molecules that enhance lymphocyte binding to both the vascular endothelium and salivary epithelium. In agreement with this hypothesis, we observed that nanomolar concentrations of LXA(4) blocked IL-1β- and TNF-α-mediated upregulation of E-selectin and intercellular cell adhesion molecule-1 (ICAM-1) on human umbilical vein endothelial cells (HUVECs). Binding of Jurkat cells to stimulated HUVECs was abrogated by LXA(4). Furthermore, LXA(4) preincubation with human submandibular gland cell line (HSG) also blocked TNF-α-mediated upregulation of vascular cell adhesion molecule-1 (VCAM-1) in these cells, and it reduced lymphocyte adhesion. These findings suggest that ALX/FPR2 and/or CysLT1 receptor activation in endothelial and epithelial cells blocks cytokine-induced adhesion molecule expression and consequent binding of lymphocytes, a critical event in the pathogenesis of Sjögren's syndrome (SS).

  10. Chronic Inflammation: Synergistic Interactions of Recruiting Macrophages (TAMs and Eosinophils (Eos with Host Mast Cells (MCs and Tumorigenesis in CALTs. M-CSF, Suitable Biomarker for Cancer Diagnosis!

    Directory of Open Access Journals (Sweden)

    Mahin Khatami

    2014-01-01

    Full Text Available Ongoing debates, misunderstandings and controversies on the role of inflammation in cancer have been extremely costly for taxpayers and cancer patients for over four decades. A reason for repeated failed clinical trials (90% ± 5 failure rates is heavy investment on numerous genetic mutations (molecular false-flags in the chaotic molecular landscape of site-specific cancers which are used for “targeted” therapies or “personalized” medicine. Recently, unresolved/chronic inflammation was defined as loss of balance between two tightly regulated and biologically opposing arms of acute inflammation (“Yin”–“Yang” or immune surveillance. Chronic inflammation could differentially erode architectural integrities in host immune-privileged or immune-responsive tissues as a common denominator in initiation and progression of nearly all age-associated neurodegenerative and autoimmune diseases and/or cancer. Analyses of data on our “accidental” discoveries in 1980s on models of acute and chronic inflammatory diseases in conjunctival-associated lymphoid tissues (CALTs demonstrated at least three stages of interactions between resident (host and recruited immune cells: (a, acute phase; activation of mast cells (MCs, IgE Abs, histamine and prostaglandin synthesis; (b, intermediate phase; down-regulation phenomenon, exhausted/degranulated MCs, heavy eosinophils (Eos infiltrations into epithelia and goblet cells (GCs, tissue hypertrophy and neovascularization; and (c, chronic phase; induction of lymphoid hyperplasia, activated macrophages (Mfs, increased (irregular size B and plasma cells, loss of integrity of lymphoid tissue capsular membrane, presence of histiocytes, follicular and germinal center formation, increased ratios of local IgG1/IgG2, epithelial thickening (growth and/or thinning (necrosis and angiogenesis. Results are suggestive of first evidence for direct association between inflammation and identifiable phases of immune

  11. Chronic Inflammation: Synergistic Interactions of Recruiting Macrophages (TAMs) and Eosinophils (Eos) with Host Mast Cells (MCs) and Tumorigenesis in CALTs. M-CSF, Suitable Biomarker for Cancer Diagnosis!

    Science.gov (United States)

    Khatami, Mahin

    2014-01-27

    Ongoing debates, misunderstandings and controversies on the role of inflammation in cancer have been extremely costly for taxpayers and cancer patients for over four decades. A reason for repeated failed clinical trials (90% ± 5 failure rates) is heavy investment on numerous genetic mutations (molecular false-flags) in the chaotic molecular landscape of site-specific cancers which are used for "targeted" therapies or "personalized" medicine. Recently, unresolved/chronic inflammation was defined as loss of balance between two tightly regulated and biologically opposing arms of acute inflammation ("Yin"-"Yang" or immune surveillance). Chronic inflammation could differentially erode architectural integrities in host immune-privileged or immune-responsive tissues as a common denominator in initiation and progression of nearly all age-associated neurodegenerative and autoimmune diseases and/or cancer. Analyses of data on our "accidental" discoveries in 1980s on models of acute and chronic inflammatory diseases in conjunctival-associated lymphoid tissues (CALTs) demonstrated at least three stages of interactions between resident (host) and recruited immune cells: (a), acute phase; activation of mast cells (MCs), IgE Abs, histamine and prostaglandin synthesis; (b), intermediate phase; down-regulation phenomenon, exhausted/degranulated MCs, heavy eosinophils (Eos) infiltrations into epithelia and goblet cells (GCs), tissue hypertrophy and neovascularization; and (c), chronic phase; induction of lymphoid hyperplasia, activated macrophages (Mfs), increased (irregular size) B and plasma cells, loss of integrity of lymphoid tissue capsular membrane, presence of histiocytes, follicular and germinal center formation, increased ratios of local IgG1/IgG2, epithelial thickening (growth) and/or thinning (necrosis) and angiogenesis. Results are suggestive of first evidence for direct association between inflammation and identifiable phases of immune dysfunction in the direction of

  12. Chronic Inflammation: Synergistic Interactions of Recruiting Macrophages (TAMs) and Eosinophils (Eos) with Host Mast Cells (MCs) and Tumorigenesis in CALTs. M-CSF, Suitable Biomarker for Cancer Diagnosis!

    Energy Technology Data Exchange (ETDEWEB)

    Khatami, Mahin [Inflammation and Cancer Biology, National Cancer Institute (Ret), the National Institutes of Health, Bethesda, MD 20817 (United States)

    2014-01-27

    Ongoing debates, misunderstandings and controversies on the role of inflammation in cancer have been extremely costly for taxpayers and cancer patients for over four decades. A reason for repeated failed clinical trials (90% ± 5 failure rates) is heavy investment on numerous genetic mutations (molecular false-flags) in the chaotic molecular landscape of site-specific cancers which are used for “targeted” therapies or “personalized” medicine. Recently, unresolved/chronic inflammation was defined as loss of balance between two tightly regulated and biologically opposing arms of acute inflammation (“Yin”–“Yang” or immune surveillance). Chronic inflammation could differentially erode architectural integrities in host immune-privileged or immune-responsive tissues as a common denominator in initiation and progression of nearly all age-associated neurodegenerative and autoimmune diseases and/or cancer. Analyses of data on our “accidental” discoveries in 1980s on models of acute and chronic inflammatory diseases in conjunctival-associated lymphoid tissues (CALTs) demonstrated at least three stages of interactions between resident (host) and recruited immune cells: (a), acute phase; activation of mast cells (MCs), IgE Abs, histamine and prostaglandin synthesis; (b), intermediate phase; down-regulation phenomenon, exhausted/degranulated MCs, heavy eosinophils (Eos) infiltrations into epithelia and goblet cells (GCs), tissue hypertrophy and neovascularization; and (c), chronic phase; induction of lymphoid hyperplasia, activated macrophages (Mϕs), increased (irregular size) B and plasma cells, loss of integrity of lymphoid tissue capsular membrane, presence of histiocytes, follicular and germinal center formation, increased ratios of local IgG1/IgG2, epithelial thickening (growth) and/or thinning (necrosis) and angiogenesis. Results are suggestive of first evidence for direct association between inflammation and identifiable phases of immune

  13. Interferon-inducible GTPases in cell autonomous and innate immunity.

    Science.gov (United States)

    Meunier, Etienne; Broz, Petr

    2016-02-01

    Detection and clearance of invading pathogens requires a coordinated response of the adaptive and innate immune system. Host cell, however, also features different mechanisms that restrict pathogen replication in a cell-intrinsic manner, collectively referred to as cell-autonomous immunity. In immune cells, the ability to unleash those mechanisms strongly depends on the activation state of the cell, which is controlled by cytokines or the detection of pathogen-associated molecular patterns by pattern-recognition receptors. The interferon (IFN) class of cytokines is one of the strongest inducers of antimicrobial effector mechanisms and acts against viral, bacterial and parasitic intracellular pathogens. This has been linked to the upregulation of several hundreds of IFN-stimulated genes, among them the so-called IFN-inducible GTPases. Two subfamilies of IFN-inducible GTPases, the immunity-related GTPases (IRGs) and the guanylate-binding proteins (GBPs), have gained attention due to their exceptional ability to specifically target intracellular vacuolar pathogens and restrict their replication by destroying their vacuolar compartment. Their repertoire has recently been expanded to the regulation of inflammasome complexes, which are cytosolic multi-protein complexes that control an inflammatory cell death called pyroptosis and the release of cytokines like interleukin-1β and interleukin-18. Here we discuss recent advances in understanding the function, the targeting and regulation of IRG and GBP proteins during microbial infections.

  14. Intestinal epithelial cells and their role in innate mucosal immunity

    OpenAIRE

    Maldonado-Contreras, A. L.; McCormick, Beth A

    2010-01-01

    The mucosal surfaces of the respiratory, gastrointestinal and urogenital tracts are covered by a layer of epithelial cells that are responsible for sensing and promoting a host immune response in order to establish the limits not only for commensal microorganisms but also for foreign organisms or particles. This is a remarkable task as the human body represents a composite of about 10 trillion human-self cells plus non-self cells from autochthonous or indigenous microbes that outnumber human ...

  15. Marginal zone B-cells, a gatekeeper of innate immunity

    Directory of Open Access Journals (Sweden)

    Moncef eZOUALI

    2011-12-01

    Full Text Available To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B-lymphocytes were initially thought to only play a role in the adaptative branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount local antibody response against type 2 T-independent (TI-2 antigens, MZ B-cells can participate to T-dependent (TD immune response through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in rodents and primates. We also summarize studies —performed in transgenic mice expressing fully human antibodies on their B-cells and macaques whose infection with Simian Immunodeficiency Virus (SIV represents a suitable model for HIV-1 infection in humans— showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells —MZ B-cells and/or B1 B-cells— with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies.

  16. Stimulation of protein kinase C recruits covert calcium channels in Aplysia bag cell neurons.

    Science.gov (United States)

    Strong, J A; Fox, A P; Tsien, R W; Kaczmarek, L K

    The modulation of voltage-activated calcium currents by protein kinases provides excitable cells with a mechanism for regulating their electrical behaviour. At the single channel level, modulation of calcium current has, to date, been characterized only in cardiac muscle, where beta-adrenergic agonists, acting through cyclic AMP-dependent protein kinase, enhance the calcium current by increasing channel availability and opening. We now report that enhancement of calcium current in the peptidergic bag cell neurons of Aplysia by protein kinase C occurs through a different mechanism, the recruitment of a previously covert class of calcium channel. Under control conditions, bag cell neurons contain only one class of voltage-activated calcium channel with a conductance of approximately 12 pS. After exposure to agents that activate protein kinase C, these neurons also express a second class of calcium channel with a different unitary conductance (approximately 24 pS) that is never seen in untreated cells.

  17. Asthmatic bronchial epithelium activated by the proteolytic allergen Der p 1 increases selective dendritic cell recruitment.

    Science.gov (United States)

    Pichavant, Muriel; Charbonnier, Anne-Sophie; Taront, Solenne; Brichet, Anne; Wallaert, Benoît; Pestel, Joel; Tonnel, André-Bernard; Gosset, Philippe

    2005-04-01

    Airway dendritic cells (DCs) are crucial for allergen-induced sensitization and inflammation in allergic asthma. After allergen challenge, an increased number of DCs is observed in airway epithelium from patients with allergy. Because Der p 1, a cysteine protease allergen from Dermatophagoides pteronyssinus , induces chemokine production by bronchial epithelial cells (BECs), the purpose of this investigation was to evaluate the capacity of BEC exposed to Der p 1 to recruit DCs. Chemotactic activity of BEAS-2B, a bronchial epithelial cell line, and BECs from nonatopic controls and patients with allergic asthma was evaluated on the migration of precursors, immature and mature monocyte-derived DCs (MDDCs), and CD34 + -derived Langerhans cells (LCs). C-C chemokine ligand (CCL)-2, CCL5, and C-X-C chemokine ligand 10 production by BEAS-2B and BEC was increased after Der p 1 exposure, whereas the proenzyme proDer p 1 devoid of enzymatic activity had no effect. Der p 1 stimulation of BEAS-2B and BEC from both groups increased significantly the recruitment of MDDC precursors, depending on CCL2, CCL5, and C-X-C chemokine ligand 10 production. In a reconstituted polarized epithelium, apical application of Der p 1 enhanced MDDC precursor migration into the epithelial layer. Moreover, Der p 1 stimulation of BEC from patients with asthma but not from controls increased the migration of LC precursors, mainly dependent on CCL20 secretion. No migration of immature and mature DCs was observed. These data confirmed that BECs participate in the homeostasis of the DC network present within the bronchial epithelium through the secretion of chemokines. In allergic asthma, upregulation of CCL20 production induced LC recruitment, the role of which remains to be determined.

  18. Virus-cell fusion as a trigger of innate immunity dependent on the adaptor STING

    Science.gov (United States)

    Holm, Christian K; Jensen, Søren B; Jakobsen, Martin R; Cheshenko, Natalia; Horan, Kristy A; Moeller, Hanne B; Gonzalez-Dosal, Regina; Rasmussen, Simon B; Christensen, Maria H.; Yarovinsky, Timur O; Rixon, Frazer J; Herold, Betsy C; Fitzgerald, Katherine A; Paludan, Søren R

    2012-01-01

    The innate immune system senses infection by detecting evolutionarily conserved molecules essential for microbial survival or abnormal location of molecules. Here we demonstrate the existence of a novel innate detection mechanism, which is induced by fusion between viral envelopes and target cells. Virus-cell fusion specifically stimulated a type I interferon (IFN) response with expression of IFN-stimulated genes (ISGs), in vivo recruitment of leukocytes, and potentiation of Toll-like receptor 7 and 9 signaling. The fusion dependent response was dependent on stimulator of interferon genes (STING) but independent of DNA, RNA and viral capsid. We suggest that membrane fusion is sensed as a danger signal with potential implications for defense against enveloped viruses and various conditions of giant cell formation. PMID:22706339

  19. From T cell "exhaustion" to anti-cancer immunity.

    Science.gov (United States)

    Verdeil, Grégory; Fuertes Marraco, Silvia A; Murray, Timothy; Speiser, Daniel E

    2016-01-01

    The immune system has the potential to protect from malignant diseases for extended periods of time. Unfortunately, spontaneous immune responses are often inefficient. Significant effort is required to develop reliable, broadly applicable immunotherapies for cancer patients. A major innovation was transplantation with hematopoietic stem cells from genetically distinct donors for patients with hematologic malignancies. In this setting, donor T cells induce long-term remission by keeping cancer cells in check through powerful allogeneic graft-versus-leukemia effects. More recently, a long awaited breakthrough for patients with solid tissue cancers was achieved, by means of therapeutic blockade of T cell inhibitory receptors. In untreated cancer patients, T cells are dysfunctional and remain in a state of T cell "exhaustion". Nonetheless, they often retain a high potential for successful defense against cancer, indicating that many T cells are not entirely and irreversibly exhausted but can be mobilized to become highly functional. Novel antibody therapies that block inhibitory receptors can lead to strong activation of anti-tumor T cells, mediating clinically significant anti-cancer immunity for many years. Here we review these new treatments and the current knowledge on tumor antigen-specific T cells.

  20. Follicular helper T cell in immunity and autoimmunity

    Directory of Open Access Journals (Sweden)

    D. Mesquita Jr

    2016-01-01

    Full Text Available The traditional concept that effector T helper (Th responses are mediated by Th1/Th2 cell subtypes has been broadened by the recent demonstration of two new effector T helper cells, the IL-17 producing cells (Th17 and the follicular helper T cells (Tfh. These new subsets have many features in common, such as the ability to produce IL-21 and to express the IL-23 receptor (IL23R, the inducible co-stimulatory molecule ICOS, and the transcription factor c-Maf, all of them essential for expansion and establishment of the final pool of both subsets. Tfh cells differ from Th17 by their ability to home to B cell areas in secondary lymphoid tissue through interactions mediated by the chemokine receptor CXCR5 and its ligand CXCL13. These CXCR5+ CD4+ T cells are considered an effector T cell type specialized in B cell help, with a transcriptional profile distinct from Th1 and Th2 cells. The role of Tfh cells and its primary product, IL-21, on B-cell activation and differentiation is essential for humoral immunity against infectious agents. However, when deregulated, Tfh cells could represent an important mechanism contributing to exacerbated humoral response and autoantibody production in autoimmune diseases. This review highlights the importance of Tfh cells by focusing on their biology and differentiation processes in the context of normal immune response to infectious microorganisms and their role in the pathogenesis of autoimmune diseases.

  1. T cell immune responses in psoriasis.

    Directory of Open Access Journals (Sweden)

    Zohre Jadali

    2014-08-01

    Full Text Available A central role for T cells and their cytokines in the pathogenesis of psoriasis has been proposed; however, there are controversies over the details of this issue. The goal of this study is to summarise currently available data on the importance of T cells in psoriasis pathogenesis. A systematic review of the English medical literature was conducted by searching PubMed, Embase, ISI Web of Knowledge, and Iranian databases including Iranmedex, and SID for studies on associations between the involvement of T cell subsets and psoriasis. The results of the present study indicate that alterations in the number and function of different subsets of T-cells are associated with psoriasis. It appears that studies on T cell subsets contributed to understanding the immunopathogenesis of psoriasis. In addition, it may have provided novel therapeutic opportunities in ameliorating immunopathologies.

  2. Positive control of cell division: FtsZ is recruited by SsgB during sporulation of Streptomyces

    NARCIS (Netherlands)

    Willemse, J.; Borst, J.W.; Waal, de E.; Bisseling, T.; Wezel, van G.P.

    2011-01-01

    In bacteria that divide by binary fission, cell division starts with the polymerization of the tubulin homolog FtsZ at mid-cell to form a cell division scaffold (the Z ring), followed by recruitment of the other divisome components. The current view of bacterial cell division control starts from the

  3. Hypoxia-induced lysyl oxidase is a critical mediator of bone marrow cell recruitment to form the premetastatic niche.

    Science.gov (United States)

    Erler, Janine T; Bennewith, Kevin L; Cox, Thomas R; Lang, Georgina; Bird, Demelza; Koong, Albert; Le, Quynh-Thu; Giaccia, Amato J

    2009-01-06

    Tumor cell metastasis is facilitated by "premetastatic niches" formed in destination organs by invading bone marrow-derived cells (BMDCs). Lysyl oxidase (LOX) is critical for premetastatic niche formation. LOX secreted by hypoxic breast tumor cells accumulates at premetastatic sites, crosslinks collagen IV in the basement membrane, and is essential for CD11b+ myeloid cell recruitment. CD11b+ cells adhere to crosslinked collagen IV and produce matrix metalloproteinase-2, which cleaves collagen, enhancing the invasion and recruitment of BMDCs and metastasizing tumor cells. LOX inhibition prevents CD11b+ cell recruitment and metastatic growth. CD11b+ cells and LOX also colocalize in biopsies of human metastases. Our findings demonstrate a critical role for LOX in premetastatic niche formation and support targeting LOX for the treatment and prevention of metastatic disease.

  4. Intercellular Communication of Tumor Cells and Immune Cells after Exposure to Different Ionizing Radiation Qualities

    Directory of Open Access Journals (Sweden)

    Sebastian Diegeler

    2017-06-01

    Full Text Available Ionizing radiation can affect the immune system in many ways. Depending on the situation, the whole body or parts of the body can be acutely or chronically exposed to different radiation qualities. In tumor radiotherapy, a fractionated exposure of the tumor (and surrounding tissues is applied to kill the tumor cells. Currently, mostly photons, and also electrons, neutrons, protons, and heavier particles such as carbon ions, are used in radiotherapy. Tumor elimination can be supported by an effective immune response. In recent years, much progress has been achieved in the understanding of basic interactions between the irradiated tumor and the immune system. Here, direct and indirect effects of radiation on immune cells have to be considered. Lymphocytes for example are known to be highly radiosensitive. One important factor in indirect interactions is the radiation-induced bystander effect which can be initiated in unexposed cells by expression of cytokines of the irradiated cells and by direct exchange of molecules via gap junctions. In this review, we summarize the current knowledge about the indirect effects observed after exposure to different radiation qualities. The different immune cell populations important for the tumor immune response are natural killer cells, dendritic cells, and CD8+ cytotoxic T-cells. In vitro and in vivo studies have revealed the modulation of their functions due to ionizing radiation exposure of tumor cells. After radiation exposure, cytokines are produced by exposed tumor and immune cells and a modulated expression profile has also been observed in bystander immune cells. Release of damage-associated molecular patterns by irradiated tumor cells is another factor in immune activation. In conclusion, both immune-activating and -suppressing effects can occur. Enhancing or inhibiting these effects, respectively, could contribute to modified tumor cell killing after radiotherapy.

  5. Orchestrating an immune response against cancer with engineered immune cells expressing αβTCRs, CARs, and innate immune receptors: an immunological and regulatory challenge.

    Science.gov (United States)

    de Witte, Moniek A; Kierkels, Guido J J; Straetemans, Trudy; Britten, Cedrik M; Kuball, Jürgen

    2015-07-01

    Over half a century ago, the first allogeneic stem cell transplantation (allo-SCT) initiated cellular immunotherapy. For several decades, little progress was made, and toxicity of allo-SCT remained a major challenge. However, recent breakthroughs have opened new avenues to further develop this modality and to provide less toxic and equally efficient interventions for patients suffering from hematological or solid malignancies. Current novel cellular immune interventions include ex vivo expansion and adoptive transfer of tumor-infiltrating immune cells or administration of drugs which antagonize tolerizing mechanisms. Alternatively, transfer of immune cells engineered to express defined T cell receptors (TCRs) and chimeric antigen receptors (CARs) has shown its potential. A valuable addition to 'engineered' adaptive immunity has emerged recently through the improved understanding of how innate immune cells can attack cancer cells without substantial side effects. This has enabled the development of transplantation platforms with limited side effects allowing early immune interventions as well as the design of engineered immune cells expressing innate immune receptors. Here, we focus on innate immune interventions and their orchestration with TCR- and CAR-engineered immune cells. In addition, we discuss how the exploitation of the full potential of cellular immune interventions is influenced by regulatory frameworks. Finally, we highlight and discuss substantial differences in the current landscape of clinical trials in Europe as compared to the USA. The aim is to stimulate international efforts to support regulatory authorities and funding agencies, especially in Europe, to create an environment that will endorse the development of engineered immune cells for the benefit of patients.

  6. The role of immune system exhaustion on cancer cell escape and anti-tumor immune induction after irradiation.

    Science.gov (United States)

    Mendes, Fernando; Domingues, Cátia; Rodrigues-Santos, Paulo; Abrantes, Ana Margarida; Gonçalves, Ana Cristina; Estrela, Jéssica; Encarnação, João; Pires, Ana Salomé; Laranjo, Mafalda; Alves, Vera; Teixo, Ricardo; Sarmento, Ana Bela; Botelho, Maria Filomena; Rosa, Manuel Santos

    2016-04-01

    Immune surveillance seems to represent an effective tumor suppressor mechanism. However, some cancer cells survive and become variants, being poorly immunogenic and able to enter a steady-state phase. These cells become functionally dormant or remain hidden clinically throughout. Neoplastic cells seem to be able to instruct immune cells to undergo changes promoting malignancy. Radiotherapy may act as a trigger of the immune response. After radiotherapy a sequence of reactions occurs, starting in the damage of oncogenic cells by multiple mechanisms, leading to the immune system positive feedback against the tumor. The link between radiotherapy and the immune system is evident. T cells, macrophages, Natural Killer cells and other immune cells seem to have a key role in controlling the tumor. T cells may be dysfunctional and remain in a state of T cell exhaustion, nonetheless, they often retain a high potential for successful defense against cancer, being able to be mobilized to become highly functional. The lack of clinical trials on a large scale makes data a little robust, in spite of promising information, there are still many variables in the studies relating to radiation and immune system. The clarification of the mechanisms underlying immune response to radiation exposure may contribute to treatment improvement, gain of life quality and span of patients.

  7. B-1 cells and concomitant immunity in Ehrlich tumour progression.

    Science.gov (United States)

    Azevedo, M C; Palos, M C; Osugui, L; Laurindo, M F; Masutani, D; Nonogaki, S; Bachi, A L L; Melo, F H M; Mariano, M

    2014-05-01

    Concomitant immunity is a phenomenon in which a tumour-bearing host is resistant to the growth of an implanted secondary tumour. Metastases are considered to be secondary tumours that develop spontaneously during primary tumour growth, suggesting the involvement of concomitant immunity in controlling the rise of metastases. It has been demonstrated that B-1 cells, a subset of B-lymphocytes found predominantly in pleural and peritoneal cavities, not only increase the metastatic development of murine melanoma B16F10, but also are capable of differentiating into mononuclear phagocytes, modulating inflammatory responses in wound healing, in oral tolerance and in Paracoccidiose brasiliensis infections. Here, we studied B-1 cells' participation in concomitant immunity during Ehrlich tumour progression. Our results show that B-1 cells obtained from BALB/c mice previously injected with Ehrlich tumour in the footpad were able to protect BALB/c and BALB/Xid mice against Ehrlich tumour challenge. In addition, it was demonstrated that BALB/Xid show faster tumour growth and have lost concomitant immunity, and that this state can be partially restored by reconstituting these animals with B-1 cells. However, further researches are required to establish the mechanism involving B-1 cells in Ehrlich tumour growth. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. Interactions between MSCs and Immune Cells: Implications for Bone Healing

    Directory of Open Access Journals (Sweden)

    Tracy K. Kovach

    2015-01-01

    Full Text Available It is estimated that, of the 7.9 million fractures sustained in the United States each year, 5% to 20% result in delayed or impaired healing requiring therapeutic intervention. Following fracture injury, there is an initial inflammatory response that plays a crucial role in bone healing; however, prolonged inflammation is inhibitory for fracture repair. The precise spatial and temporal impact of immune cells and their cytokines on fracture healing remains obscure. Some cytokines are reported to be proosteogenic while others inhibit bone healing. Cell-based therapy utilizing mesenchymal stromal cells (MSCs is an attractive option for augmenting the fracture repair process. Osteoprogenitor MSCs not only differentiate into bone, but they also exert modulatory effects on immune cells via a variety of mechanisms. In this paper, we review the current literature on both in vitro and in vivo studies on the role of the immune system in fracture repair, the use of MSCs in the enhancement of fracture healing, and interactions between MSCs and immune cells. Insight into this paradigm can provide valuable clues in identifying cellular and noncellular targets that can potentially be modulated to enhance both natural bone healing and bone repair augmented by the exogenous addition of MSCs.

  9. Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance.

    Science.gov (United States)

    Lee, K J; Moon, J Y; Choi, H K; Kim, H O; Hur, G Y; Jung, K H; Lee, S Y; Kim, J H; Shin, C; Shim, J J; In, K H; Yoo, S H; Kang, K H; Lee, S Y

    2010-08-01

    Statins are potent inhibitors of hydroxyl-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, and have emerged as potential anti-cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)-10, transforming growth factor (TGF)-beta and indoleamine-2,3-dioxygenase (IDO) by tumours, which induce a regulatory T cell (T(reg)) response. In this study, we investigated the effect of simvastatin on the production of IL-10, TGF-beta and IDO production and the proliferation of T(regs) using several cancer cell lines, and Lewis lung cancer (3LL) cells-inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI-H292). The production of the immune regulatory markers IL-10, TGF-beta in 3LL and NCI-H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin-treated mice groups. Therefore, while simvastatin had an anti-proliferative effect, it also exhibited immune tolerance-promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

  10. Demineralized Bone Matrix Scaffolds Modified by CBD-SDF-1α Promote Bone Regeneration via Recruiting Endogenous Stem Cells.

    Science.gov (United States)

    Shi, Jiajia; Sun, Jie; Zhang, Wen; Liang, Hui; Shi, Qin; Li, Xiaoran; Chen, Yanyan; Zhuang, Yan; Dai, Jianwu

    2016-10-07

    The reconstruction of bone usually depends on substitute transplantation, which has drawbacks including the limited bone substitutes available, comorbidity, immune rejection, and limited endogenous bone regeneration. Here, we constructed a functionalized bone substitute by combining application of the demineralized bone matrix (DBM) and collagen-binding stromal-cell-derived factor-1α (CBD-SDF-1α). DBM was a poriferous and biodegradable bone substitute, derived from bovine bone and consisting mainly of collagen. CBD-SDF-1α could bind to collagen and be controllably released from the DBM to mobilize stem cells. In a rat femur defect model, CBD-SDF-1α-modified DBM scaffolds could efficiently mobilize CD34(+) and c-kit(+) endogenous stem cells homing to the injured site at 3 days after implantation. According to the data from micro-CT, CBD-SDF-1α-modified DBM scaffolds could help the bone defects rejoin with mineralization accumulated and bone volume expanded. Interestingly, osteoprotegerin (OPG) and osteopontin (OPN) were highly expressed in CBD-SDF-1α group at an early time after implantation, while osteocalcin (OCN) was more expanded. H&E and Masson's trichrome staining showed that the CBD-SDF-1α-modified DBM scaffold group had more osteoblasts and that the bone defect rejoined earlier. The ultimate strength of the regenerated bone was investigated by three-point bending, showing that the CBD-SDF-1α group had superior strength. In conclusion, CBD-SDF-1α-modified DBM scaffolds could promote bone regeneration by recruiting endogenous stem cells.

  11. The Reorientation of T-Cell Polarity and Inhibition of Immunological Synapse Formation by CD46 Involves Its Recruitment to Lipid Rafts

    Directory of Open Access Journals (Sweden)

    Mandy J. Ludford-Menting

    2011-01-01

    Full Text Available Many infectious agents utilize CD46 for infection of human cells, and therapeutic applications of CD46-binding viruses are now being explored. Besides mediating internalization to enable infection, binding to CD46 can directly alter immune function. In particular, ligation of CD46 by antibodies or by measles virus can prevent activation of T cells by altering T-cell polarity and consequently preventing the formation of an immunological synapse. Here, we define a mechanism by which CD46 reorients T-cell polarity to prevent T-cell receptor signaling in response to antigen presentation. We show that CD46 associates with lipid rafts upon ligation, and that this reduces recruitment of both lipid rafts and the microtubule organizing centre to the site of receptor cross-linking. These data combined indicate that polarization of T cells towards the site of CD46 ligation prevents formation of an immunological synapse, and this is associated with the ability of CD46 to recruit lipid rafts away from the site of TCR ligation.

  12. Injection of SDF-1 loaded nanoparticles following traumatic brain injury stimulates neural stem cell recruitment.

    Science.gov (United States)

    Zamproni, Laura N; Mundim, Mayara V; Porcionatto, Marimelia A; des Rieux, Anne

    2017-03-15

    Recruiting neural stem cell (NSC) at the lesion site is essential for central nervous system repair. This process could be triggered by the local delivery of the chemokine SDF-1. We compared two PLGA formulations for local brain SDF-1 delivery: SDF-1 loaded microspheres (MS) and SDF-1 loaded nanoparticles (NP). Both formulations were able to encapsulate more than 80% of SDF-1 but presented different release profiles, with 100% of SDF-1 released after 6days for the MS and with 25% of SDF-1 released after 2 weeks for NP. SDF-1 bioactivity was demonstrated by a chemotactic assay. When injected in mouse brain after traumatic brain injury, only SDF-1 nanoparticles induced NSC migration to the damage area. More neuroblasts (DCX+ cells) could be visualized around the lesions treated with NP SDF-1 compared to the other conditions. Rostral migratory stream destabilization with massive migration of DCX+ cell toward the perilesional area was observed 2 weeks after NP SDF-1 injection. Local injection of SDF-1-loaded nanoparticles induces recruitment of NSC and could be promising for brain injury lesion.

  13. Nucleoid occlusion protein Noc recruits DNA to the bacterial cell membrane.

    Science.gov (United States)

    Adams, David William; Wu, Ling Juan; Errington, Jeff

    2015-02-12

    To proliferate efficiently, cells must co-ordinate division with chromosome segregation. In Bacillus subtilis, the nucleoid occlusion protein Noc binds to specific DNA sequences (NBSs) scattered around the chromosome and helps to protect genomic integrity by coupling the initiation of division to the progression of chromosome replication and segregation. However, how it inhibits division has remained unclear. Here, we demonstrate that Noc associates with the cell membrane via an N-terminal amphipathic helix, which is necessary for function. Importantly, the membrane-binding affinity of this helix is weak and requires the assembly of nucleoprotein complexes, thus establishing a mechanism for DNA-dependent activation of Noc. Furthermore, division inhibition by Noc requires recruitment of NBS DNA to the cell membrane and is dependent on its ability to bind DNA and membrane simultaneously. Indeed, Noc production in a heterologous system is sufficient for recruitment of chromosomal DNA to the membrane. Our results suggest a simple model in which the formation of large membrane-associated nucleoprotein complexes physically occludes assembly of the division machinery.

  14. Immunity to pathogens taught by specialized human dendritic cell subsets.

    Directory of Open Access Journals (Sweden)

    Jens A. E. Geginat

    2015-10-01

    Full Text Available Dendritic cells (DC are specialized antigen-presenting cells (APC that have a key role in immune responses, because they bridge the innate and adaptive arms of the immune system. They mature upon recognition of pathogens and up-regulate MHC molecules and co-stimulatory receptors to activate antigen-specific CD4+ and CD8+ T-cells. It is now well established that DC are not a homogeneous population, but are composed of different subsets with specialized functions in immune responses to specific pathogens. Upon viral infections, plasmacytoid DC (pDC rapidly produce large amounts of IFN-α, which has potent anti-viral functions and activates several other immune cells. However, pDC are not particularly potent APC and induce the tolerogenic cytokine IL-10 in CD4+ T-cells. In contrast, myeloid DC (mDC are very potent APC and possess the unique capacity to prime naïve T-cells and consequently to initiate a primary adaptive immune response. Different subsets of myeloid DC with specialized functions have been identified. In mice, CD8α+ mDC capture antigenic material from necrotic cells, secrete high levels of IL-12, and prime Th1 and cytotoxic T cell responses to control intracellular pathogens. Conversely, CD8α- mDC preferentially prime CD4+ T-cells and promote Th2 or Th17 differentiation. BDCA-3+ mDC2 are the human homologue of CD8α+ mDC, since they share the expression of several key molecules, the capacity to cross-present antigens to CD8+ T-cells and to produce IFN-λ. However, although several features of the DC network are conserved between humans and mice, the expression of several relevant toll-like receptors as well as the production of cytokines that regulate T-cell differentiation are different. Intriguingly, recent data suggests specific roles for human DC subsets in immune responses against individual pathogens. The biology of human DC subsets holds the promise to be exploitable in translational medicine, in particular for the

  15. Role of the immune cells, mediators and cytokines in pathogenesis of asthma: a review article

    Directory of Open Access Journals (Sweden)

    Sedigheh Bahrami Mahne

    2014-08-01

    Full Text Available Asthma is a chronic inflammatory disorder of the airways, associated with airway re-modeling and hyperresponsiveness. It is expressed that asthma influences about 300 million people around the world, which is estimated to increase to about 400 million by 2025. The prevalence rate is 15 to 20 percent in children and 5 to 10 percent in adults, while its trend is still increasing. Inflammation plays an important role in the patho-physiology of asthma, which involves an interaction of different types of the immune cells and mediators. It leads to a number of pathophysiology changes, including bron-chial inflammation, airway obstruction, and clinical episodes such as cough, wheeze and shortness of breath. Asthma is now greatly being introduced as a heterogeneous disorder and it is pointed out to the role of T cells, including Th1, Th2, Th17, and regu-latory T cells. Other immune cells, especially neutrophils, macrophages and dendritic cells, as well structural cells such as epithelial and airway smooth muscle cells also pro-duce disease-associated cytokines in asthma. Increased levels of these immune cells and cytokines have been recognized in clinical samples and mouse models of asthma. Different cytokines, including pro-inflammatory cytokines (such as TNFα, IL-1, and IL-6, T helper 2 cytokines (such as IL-4, IL-5, IL-9, IL-13, and growth factors (such as GM-CSF, PDGF play a role in the pathogenesis of asthma. Indeed chemokines (such as MPC-1, RANTES , MIP-1 and the chemokine receptors (such as CCR3, CCR4, CCL11, CCL24, and CCL26 play an important role in the recruitment of circu-lating inflammatory cells into the airways in asthmatic patients and also is related with increased T helper 2 cytokines after inhaled allergens. Among new approaches, treat-ment of asthma with anti-cytokine drugs such as antibodies blocking IL-4, IL-5, IL-9 could reduce recruitment inflammatory cells into the airways and remodeling. The final perspective of asthma

  16. Innate immune response to pulmonary contusion: identification of cell type-specific inflammatory responses.

    Science.gov (United States)

    Hoth, J Jason; Wells, Jonathan D; Yoza, Barbara K; McCall, Charles E

    2012-04-01

    Lung injury from pulmonary contusion is a common traumatic injury, predominantly seen after blunt chest trauma, such as in vehicular accidents. The local and systemic inflammatory response to injury includes activation of innate immune receptors, elaboration of a variety of inflammatory mediators, and recruitment of inflammatory cells to the injured lung. Using a mouse model of pulmonary contusion, we had previously shown that innate immune Toll-like receptors 2 and 4 (TLR2 and TLR4) mediate the inflammatory response to lung injury. In this study, we used chimeric mice generated by adoptive bone marrow transfer between TLR2 or TLR4 and wild-type mice. We found that, in the lung, both bone marrow-derived and nonmyeloid cells contribute to TLR-dependent inflammatory responses after injury in a cell type-specific manner. We also show a novel TLR2-dependent injury mechanism that is associated with enhanced airway epithelial cell apoptosis and increased pulmonary FasL and Fas expression in the lungs from injured mice. Thus, in addition to cardiopulmonary physiological dysfunction, cell type-specific TLR and their differential response to injury may provide novel specific targets for management of patients with pulmonary contusion.

  17. TLR4 signalling in pulmonary stromal cells is critical for inflammation and immunity in the airways.

    Science.gov (United States)

    Perros, Frederic; Lambrecht, Bart N; Hammad, Hamida

    2011-09-24

    Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway diseases. Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma. Pathologic changes induced by endotoxin inhalation include bronchospasm, airflow obstruction, recruitment of inflammatory cells, injury of the alveolar epithelium, and disruption of pulmonary capillary integrity leading to protein rich fluid leak in the alveolar space. Mammalian Toll-like receptors (TLRs) are important signalling receptors in innate host defense. Among these receptors, TLR4 plays a critical role in the response to endotoxin. Lungs are a complex compartmentalized organ with separate barriers, namely the alveolar-capillary barrier, the microvascular endothelium, and the alveolar epithelium. An emerging theme in the field of lung immunology is that structural cells (SCs) of the airways such as epithelial cells (ECs), endothelial cells, fibroblasts and other stromal cells produce activating cytokines that determine the quantity and quality of the lung immune response. This review focuses on the role of TLR4 in the innate and adaptive immune functions of the pulmonary SCs.

  18. TLR4 signalling in pulmonary stromal cells is critical for inflammation and immunity in the airways

    Directory of Open Access Journals (Sweden)

    Lambrecht Bart N

    2011-09-01

    Full Text Available Abstract Inflammation of the airways, which is often associated with life-threatening infection by Gram-negative bacteria or presence of endotoxin in the bioaerosol, is still a major cause of severe airway diseases. Moreover, inhaled endotoxin may play an important role in the development and progression of airway inflammation in asthma. Pathologic changes induced by endotoxin inhalation include bronchospasm, airflow obstruction, recruitment of inflammatory cells, injury of the alveolar epithelium, and disruption of pulmonary capillary integrity leading to protein rich fluid leak in the alveolar space. Mammalian Toll-like receptors (TLRs are important signalling receptors in innate host defense. Among these receptors, TLR4 plays a critical role in the response to endotoxin. Lungs are a complex compartmentalized organ with separate barriers, namely the alveolar-capillary barrier, the microvascular endothelium, and the alveolar epithelium. An emerging theme in the field of lung immunology is that structural cells (SCs of the airways such as epithelial cells (ECs, endothelial cells, fibroblasts and other stromal cells produce activating cytokines that determine the quantity and quality of the lung immune response. This review focuses on the role of TLR4 in the innate and adaptive immune functions of the pulmonary SCs.

  19. Immune signatures of protective spleen memory CD8 T cells.

    Science.gov (United States)

    Brinza, Lilia; Djebali, Sophia; Tomkowiak, Martine; Mafille, Julien; Loiseau, Céline; Jouve, Pierre-Emmanuel; de Bernard, Simon; Buffat, Laurent; Lina, Bruno; Ottmann, Michèle; Rosa-Calatrava, Manuel; Schicklin, Stéphane; Bonnefoy, Nathalie; Lauvau, Grégoire; Grau, Morgan; Wencker, Mélanie; Arpin, Christophe; Walzer, Thierry; Leverrier, Yann; Marvel, Jacqueline

    2016-11-24

    Memory CD8 T lymphocyte populations are remarkably heterogeneous and differ in their ability to protect the host. In order to identify the whole range of qualities uniquely associated with protective memory cells we compared the gene expression signatures of two qualities of memory CD8 T cells sharing the same antigenic-specificity: protective (Influenza-induced, Flu-TM) and non-protective (peptide-induced, TIM) spleen memory CD8 T cells. Although Flu-TM and TIM express classical phenotypic memory markers and are polyfunctional, only Flu-TM protects against a lethal viral challenge. Protective memory CD8 T cells express a unique set of genes involved in migration and survival that correlate with their unique capacity to rapidly migrate within the infected lung parenchyma in response to influenza infection. We also enlighten a new set of poised genes expressed by protective cells that is strongly enriched in cytokines and chemokines such as Ccl1, Ccl9 and Gm-csf. CCL1 and GM-CSF genes are also poised in human memory CD8 T cells. These immune signatures are also induced by two other pathogens (vaccinia virus and Listeria monocytogenes). The immune signatures associated with immune protection were identified on circulating cells, i.e. those that are easily accessible for immuno-monitoring and could help predict vaccines efficacy.

  20. Immune signatures of protective spleen memory CD8 T cells

    Science.gov (United States)

    Brinza, Lilia; Djebali, Sophia; Tomkowiak, Martine; Mafille, Julien; Loiseau, Céline; Jouve, Pierre-Emmanuel; de Bernard, Simon; Buffat, Laurent; Lina, Bruno; Ottmann, Michèle; Rosa-Calatrava, Manuel; Schicklin, Stéphane; Bonnefoy, Nathalie; Lauvau, Grégoire; Grau, Morgan; Wencker, Mélanie; Arpin, Christophe; Walzer, Thierry; Leverrier, Yann; Marvel, Jacqueline

    2016-01-01

    Memory CD8 T lymphocyte populations are remarkably heterogeneous and differ in their ability to protect the host. In order to identify the whole range of qualities uniquely associated with protective memory cells we compared the gene expression signatures of two qualities of memory CD8 T cells sharing the same antigenic-specificity: protective (Influenza-induced, Flu-TM) and non-protective (peptide-induced, TIM) spleen memory CD8 T cells. Although Flu-TM and TIM express classical phenotypic memory markers and are polyfunctional, only Flu-TM protects against a lethal viral challenge. Protective memory CD8 T cells express a unique set of genes involved in migration and survival that correlate with their unique capacity to rapidly migrate within the infected lung parenchyma in response to influenza infection. We also enlighten a new set of poised genes expressed by protective cells that is strongly enriched in cytokines and chemokines such as Ccl1, Ccl9 and Gm-csf. CCL1 and GM-CSF genes are also poised in human memory CD8 T cells. These immune signatures are also induced by two other pathogens (vaccinia virus and Listeria monocytogenes). The immune signatures associated with immune protection were identified on circulating cells, i.e. those that are easily accessible for immuno-monitoring and could help predict vaccines efficacy. PMID:27883012

  1. CXCR5+ T helper cells mediate protective immunity against tuberculosis

    Science.gov (United States)

    Slight, Samantha R.; Rangel-Moreno, Javier; Gopal, Radha; Lin, Yinyao; Fallert Junecko, Beth A.; Mehra, Smriti; Selman, Moises; Becerril-Villanueva, Enrique; Baquera-Heredia, Javier; Pavon, Lenin; Kaushal, Deepak; Reinhart, Todd A.; Randall, Troy D.; Khader, Shabaana A.

    2013-01-01

    One third of the world’s population is infected with Mycobacterium tuberculosis (Mtb). Although most infected people remain asymptomatic, they have a 10% lifetime risk of developing active tuberculosis (TB). Thus, the current challenge is to identify immune parameters that distinguish individuals with latent TB from those with active TB. Using human and experimental models of Mtb infection, we demonstrated that organized ectopic lymphoid structures containing CXCR5+ T cells were present in Mtb-infected lungs. In addition, we found that in experimental Mtb infection models, the presence of CXCR5+ T cells within ectopic lymphoid structures was associated with immune control. Furthermore, in a mouse model of Mtb infection, we showed that activated CD4+CXCR5+ T cells accumulated in Mtb-infected lungs and produced proinflammatory cytokines. Mice deficient in Cxcr5 had increased susceptibility to TB due to defective T cell localization within the lung parenchyma. We demonstrated that CXCR5 expression in T cells mediated correct T cell localization within TB granulomas, promoted efficient macrophage activation, protected against Mtb infection, and facilitated lymphoid follicle formation. These data demonstrate that CD4+CXCR5+ T cells play a protective role in the immune response against TB and highlight their potential use for future TB vaccine design and therapy. PMID:23281399

  2. Evasion of T cell immunity by Epstein-Barr virus

    NARCIS (Netherlands)

    Horst, D.

    2011-01-01

    Immune evasion strategies are thought to contribute essentially to the life cycle of persistent viruses by delaying the elimination of the infected cell long enough to enable the virus to replicate. Exemplary in this context are the herpesviruses, large DNA viruses that are carried as a persistent

  3. The role of the cell wall in plant immunity

    DEFF Research Database (Denmark)

    Malinovsky, Frederikke Gro; Fangel, Jonatan Ulrik; Willats, William George Tycho

    2014-01-01

    The battle between plants and microbes is evolutionarily ancient, highly complex, and often co-dependent. A primary challenge for microbes is to breach the physical barrier of host cell walls whilst avoiding detection by the plant's immune receptors. While some receptors sense conserved microbial...

  4. Signal transduction in cells of the immune system in microgravity

    Directory of Open Access Journals (Sweden)

    Huber Kathrin

    2008-10-01

    Full Text Available Abstract Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which renders the cells of the immune system an ideal model organism to investigate the influence of gravity on the cellular and molecular level. Here we review the current knowledge about the question, if and how cellular signal transduction depends on the existence of gravity, with special focus on cells of the immune system. Since immune cell function is fundamental to keep the organism under imnological surveillance during the defence against pathogens, to investigate the effects and possible molecular mechanisms of altered gravity is indispensable for long-term space flights to Earth Moon or Mars. Thus, understanding the impact of gravity on cellular functions on Earth will provide not only important informations about the development of life on Earth, but also for therapeutic and preventive strategies to cope successfully with medical problems during space exploration.

  5. Evasion of T cell immunity by Epstein-Barr virus

    NARCIS (Netherlands)

    Horst, D.

    2011-01-01

    Immune evasion strategies are thought to contribute essentially to the life cycle of persistent viruses by delaying the elimination of the infected cell long enough to enable the virus to replicate. Exemplary in this context are the herpesviruses, large DNA viruses that are carried as a persistent a

  6. Reed-Sternberg cell-derived lymphotoxin-α activates endothelial cells to enhance T-cell recruitment in classical Hodgkin lymphoma.

    Science.gov (United States)

    Fhu, Chee Wai; Graham, Anne M; Yap, Celestial T; Al-Salam, Suhail; Castella, Antonio; Chong, Siew Meng; Lim, Yaw-Chyn

    2014-11-06

    It is known that cells within the inflammatory background in classical Hodgkin lymphoma (cHL) provide signals essential for the continual survival of the neoplastic Hodgkin and Reed-Sternberg (HRS) cells. However, the mechanisms underlying the recruitment of this inflammatory infiltrate into the involved lymph nodes are less well understood. In this study, we show in vitro that HRS cells secrete lymphotoxin-α (LTα) which acts on endothelial cells to upregulate the expression of adhesion molecules that are important for T cell recruitment. LTα also enhances the expression of hyaluronan which preferentially contributes to the recruitment of CD4(+) CD45RA(+) naïve T cells under in vitro defined flow conditions. Enhanced expression of LTα in HRS cells and tissue stroma; and hyaluronan on endothelial cells are readily detected in involved lymph nodes from cHL patients. Our study also shows that although NF-κB and AP-1 are involved, the cyclooxygenase (COX) pathway is the dominant regulator of LTα production in HRS cells. Using pharmacological inhibitors, our data suggest that activity of COX1, but not of COX2, directly regulates the expression of nuclear c-Fos in HRS cells. Our findings suggest that HRS cell-derived LTα is an important mediator that contributes to T cell recruitment into lesional lymph nodes in cHL. © 2014 by The American Society of Hematology.

  7. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack,...

  8. Ebola VP40 in exosomes can cause immune cell dysfunction

    Directory of Open Access Journals (Sweden)

    Michelle L Pleet

    2016-11-01

    Full Text Available Ebola virus (EBOV is an enveloped, ssRNA virus from the family Filoviridae capable of causing severe hemorrhagic fever with up to 80-90% mortality rates. The most recent outbreak of EBOV in West Africa starting in 2014 resulted in over 11,300 deaths; however, long-lasting persistence and recurrence in survivors has been documented, potentially leading to further transmission of the virus. We have previously shown that exosomes from cells infected with HIV-1, HTLV-1 and Rift Valley Fever virus are able to transfer viral proteins and non-coding RNAs to naïve recipient cells, resulting in an altered cellular activity. In the current manuscript, we examined the effect of Ebola structural proteins VP40, GP, NP and VLPs on recipient immune cells, as well as the effect of exosomes containing these proteins on naïve immune cells. We found that VP40-transfected cells packaged VP40 into exosomes, and that these exosomes were capable of inducing apoptosis in recipient immune cells. Additionally, we show that presence of VP40 within parental cells or in exosomes delivered to naïve cells could result in the regulation of RNAi machinery including Dicer, Drosha, and Ago 1, which may play a role in the induction of cell death in recipient immune cells. Exosome biogenesis was regulated by VP40 in transfected cells by increasing levels of ESCRT-II proteins EAP20 and EAP45, and exosomal marker proteins CD63 and Alix. VP40 was phosphorylated by Cdk2/Cyclin complexes at Serine 233 which could be reversed with r-Roscovitine treatment. The level of VP40-containing exosomes could also be regulated by treated cells with FDA-approved Oxytetracycline. Additionally, we utilized novel nanoparticles to safely capture VP40 and other viral proteins from Ebola VLPs spiked into human samples using SDS/reducing agents, thus minimizing the need for BSL-4 conditions for most downstream assays. Collectively, our data indicates that VP40 packaged into exosomes may be responsible

  9. Blocking junctional adhesion molecule C enhances dendritic cell migration and boosts the immune responses against Leishmania major.

    Science.gov (United States)

    Ballet, Romain; Emre, Yalin; Jemelin, Stéphane; Charmoy, Mélanie; Tacchini-Cottier, Fabienne; Imhof, Beat A

    2014-12-01

    The recruitment of dendritic cells to sites of infections and their migration to lymph nodes is fundamental for antigen processing and presentation to T cells. In the present study, we showed that antibody blockade of junctional adhesion molecule C (JAM-C) on endothelial cells removed JAM-C away from junctions and increased vascular permeability after L. major infection. This has multiple consequences on the output of the immune response. In resistant C57BL/6 and susceptible BALB/c mice, we found higher numbers of innate immune cells migrating from blood to the site of infection. The subsequent migration of dendritic cells (DCs) from the skin to the draining lymph node was also improved, thereby boosting the induction of the adaptive immune response. In C57BL/6 mice, JAM-C blockade after L. major injection led to an enhanced IFN-γ dominated T helper 1 (Th1) response with reduced skin lesions and parasite burden. Conversely, anti JAM-C treatment increased the IL-4-driven T helper 2 (Th2) response in BALB/c mice with disease exacerbation. Overall, our results show that JAM-C blockade can finely-tune the innate cell migration and accelerate the consequent immune response to L. major without changing the type of the T helper cell response.

  10. Blocking junctional adhesion molecule C enhances dendritic cell migration and boosts the immune responses against Leishmania major.

    Directory of Open Access Journals (Sweden)

    Romain Ballet

    2014-12-01

    Full Text Available The recruitment of dendritic cells to sites of infections and their migration to lymph nodes is fundamental for antigen processing and presentation to T cells. In the present study, we showed that antibody blockade of junctional adhesion molecule C (JAM-C on endothelial cells removed JAM-C away from junctions and increased vascular permeability after L. major infection. This has multiple consequences on the output of the immune response. In resistant C57BL/6 and susceptible BALB/c mice, we found higher numbers of innate immune cells migrating from blood to the site of infection. The subsequent migration of dendritic cells (DCs from the skin to the draining lymph node was also improved, thereby boosting the induction of the adaptive immune response. In C57BL/6 mice, JAM-C blockade after L. major injection led to an enhanced IFN-γ dominated T helper 1 (Th1 response with reduced skin lesions and parasite burden. Conversely, anti JAM-C treatment increased the IL-4-driven T helper 2 (Th2 response in BALB/c mice with disease exacerbation. Overall, our results show that JAM-C blockade can finely-tune the innate cell migration and accelerate the consequent immune response to L. major without changing the type of the T helper cell response.

  11. Lipoxin A₄ modulates adaptive immunity by decreasing memory B-cell responses via an ALX/FPR2-dependent mechanism.

    Science.gov (United States)

    Ramon, Sesquile; Bancos, Simona; Serhan, Charles N; Phipps, Richard P

    2014-02-01

    Specialized proresolving mediators are endogenous bioactive lipid molecules that play a fundamental role in the regulation of inflammation and its resolution. Lipoxins and other specialized proresolving mediators have been identified in important immunological tissues including bone marrow, spleen, and blood. Lipoxins regulate functions of the innate immune system including the promotion of monocyte recruitment and increase macrophage phagocytosis of apoptotic neutrophils. A major knowledge gap is whether lipoxins influence adaptive immune cells. Here, we analyzed the actions of lipoxin A₄ (LXA₄) and its receptor ALX/FPR2 on human and mouse B cells. LXA₄ decreased IgM and IgG production on activated human B cells through ALX/FPR2-dependent signaling, which downregulated NF-κB p65 nuclear translocation. LXA₄ also inhibited human memory B-cell antibody production and proliferation, but not naïve B-cell function. Lastly, LXA₄ decreased antigen-specific antibody production in an OVA immunization mouse model. To our knowledge, this is the first description of the actions of lipoxins on human B cells, demonstrating a link between resolution signals and adaptive immunity. Regulating antibody production is crucial to prevent unwanted inflammation. Harnessing the ability of lipoxins to decrease memory B-cell antibody production can be beneficial to threat inflammatory and autoimmune disorders.

  12. Soluble forms of VEGF receptor-1 and -2 promote vascular maturation via mural cell recruitment.

    Science.gov (United States)

    Lorquet, Sophie; Berndt, Sarah; Blacher, Silvia; Gengoux, Emily; Peulen, Olivier; Maquoi, Erik; Noël, Agnès; Foidart, Jean-Michel; Munaut, Carine; Péqueux, Christel

    2010-10-01

    Two soluble forms of vascular endothelial growth factor (VEGF) receptors, sVEGFR-1 and sVEGFR-2, are physiologically released and overproduced in some pathologies. They are known to act as anti-VEGF agents. Here we report that these soluble receptors contribute to vessel maturation by mediating a dialogue between endothelial cells (ECs) and mural cells that leads to blood vessel stabilization. Through a multidisciplinary approach, we provide evidence that these soluble VEGF receptors promote mural cell migration through a paracrine mechanism involving interplay in ECs between VEGF/VEGFR-2 and sphingosine-1-phosphate type-1 (S1P)/S1P1 pathways that leads to endothelial nitric oxyde synthase (eNOS) activation. This new paradigm is supported by the finding that sVEGFR-1 and -2 perform the following actions: 1) induce an eNOS-dependent outgrowth of a mural cell network in an ex vivo model of angiogenesis, 2) increase the mural cell coverage of neovessels in vitro and in vivo, 3) promote mural cell migration toward ECs, and 4) stimulate endothelial S1P1 overproduction and eNOS activation that promote the migration and the recruitment of neighboring mural cells. These findings provide new insights into mechanisms regulating physiological and pathological angiogenesis and vessel stabilization.

  13. The water channel aquaporin-1 contributes to renin cell recruitment during chronic stimulation of renin production.

    Science.gov (United States)

    Tinning, Anne R; Jensen, Boye L; Schweda, Frank; Machura, Katharina; Hansen, Pernille B L; Stubbe, Jane; Gramsbergen, Jan Bert; Madsen, Kirsten

    2014-12-01

    Both the processing and release of secretory granules involve water movement across granule membranes. It was hypothesized that the water channel aquaporin (AQP)1 directly contributes to the recruitment of renin-positive cells in the afferent arteriole. AQP1(-/-) and AQP1(+/+) mice were fed a low-salt (LS) diet [0.004% (wt/wt) NaCl] for 7 days and given enalapril [angiotensin-converting enzyme inhibitor (ACEI), 0.1 mg/ml] in drinking water for 3 days. There were no differences in plasma renin concentration at baseline. After LS-ACEI, plasma renin concentrations increased markedly in both genotypes but was significantly lower in AQP1(-/-) mice compared with AQP1(+/+) mice. Tissue renin concentrations were higher in AQP1(-/-) mice, and renin mRNA levels were not different between genotypes. Mean arterial blood pressure was not different at baseline and during LS diet but decreased significantly in both genotypes after the addition of ACEI; the response was faster in AQP1(-/-) mice but then stabilized at a similar level. Renin release after 200 μl blood withdrawal was not different. Isoprenaline-stimulated renin release from isolated perfused kidneys did not differ between genotypes. Cortical tissue norepinephrine concentrations were lower after LS-ACEI compared with baseline with no difference between genotypes. Plasma nitrite/nitrate concentrations were unaffected by genotype and LS-ACEI. In AQP1(-/-) mice, the number of afferent arterioles with recruitment was significantly lower compared with AQP1(+/+) mice after LS-ACEI. We conclude that AQP1 is not necessary for acutely stimulated renin secretion in vivo and from isolated perfused kidneys, whereas recruitment of renin-positive cells in response to chronic stimulation is attenuated or delayed in AQP1(-/-) mice.

  14. The Cell Birth Marker BrdU Does Not Affect Recruitment of Subsequent Cell Divisions in the Adult Avian Brain

    Science.gov (United States)

    Cattan, Anat

    2015-01-01

    BrdU is commonly used to quantify neurogenesis but also causes mutation and has mitogenic, transcriptional, and translational effects. In mammalian studies, attention had been given to its dosage, but in birds such examination was not conducted. Our previous study suggested that BrdU might affect subsequent cell divisions and neuronal recruitment in the brain. Furthermore, this effect seemed to increase with time from treatment. Accordingly, we examined whether BrdU might alter neurogenesis in the adult avian brain. We compared recruitment of [3H]-thymidine+ neurons in brains of zebra finches (Taeniopygia guttata) when no BrdU was involved and when BrdU was given 1 or 3 months prior to [3H]-thymidine. In nidopallium caudale, HVC, and hippocampus, no differences were found between groups in densities and percentages of [3H]-thymidine+ neurons. The number of silver grains per [3H]-thymidine+ neuronal nucleus and their distribution were similar across groups. Additionally, time did not affect the results. The results indicate that the commonly used dosage of BrdU in birds has no long-term effects on subsequent cell divisions and neuronal recruitment. This conclusion is also important in neuronal replacement experiments, where BrdU and another cell birth marker are given, with relatively long intervals between them. PMID:25759813

  15. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1997-01-01

    Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

  16. Ageing and cell-mediated immunity.

    Science.gov (United States)

    Fixa, B; Komárková, O; Chmelar, V

    1975-01-01

    The lymphocyte transformation test with phytohemagglutinin as mitogen estimated according to the incorporation of 2-(14)C-thymidine in DNA was used as an indicator of cell-mediated reactivity in 53 healthy subjects. Three age groups were examined: up to 20 years (21 subjects), 21-40 years (10 subjects) and over 70 years (22 subjects). The responsiveness of lymphocytes decreased significantly with age. In the highest age group 12 pathologically low values were found.

  17. In vivo imaging of immune cell trafficking in cancer.

    Science.gov (United States)

    Ottobrini, Luisa; Martelli, Cristina; Trabattoni, Daria Lucia; Clerici, Mario; Lucignani, Giovanni

    2011-05-01

    Tumour establishment, progression and regression can be studied in vivo using an array of imaging techniques ranging from MRI to nuclear-based and optical techniques that highlight the intrinsic behaviour of different cell populations in the physiological context. Clinical in vivo imaging techniques and preclinical specific approaches have been used to study, both at the macroscopic and microscopic level, tumour cells, their proliferation, metastasisation, death and interaction with the environment and with the immune system. Fluorescent, radioactive or paramagnetic markers were used in direct protocols to label the specific cell population and reporter genes were used for genetic, indirect labelling protocols to track the fate of a given cell subpopulation in vivo. Different protocols have been proposed to in vivo study the interaction between immune cells and tumours by different imaging techniques (intravital and whole-body imaging). In particular in this review we report several examples dealing with dendritic cells, T lymphocytes and macrophages specifically labelled for different imaging procedures both for the study of their physiological function and in the context of anti-neoplastic immunotherapies in the attempt to exploit imaging-derived information to improve and optimise anti-neoplastic immune-based treatments.

  18. Differential protective effects of immune lymphoid cells against transplanted line Ib leukemia and immune polioencephalomyelitis. [X radiation, mice

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, P.S.; Lukasewycz, O.A.; Olson, D.S.; Murphy, W.H.

    1978-12-01

    The capacity of immune cells obtained from the major lymphoid compartments to protect C58 mice from transplanted line Ib leukemia, and from an age-dependent autoimmune CNS disease (immune polioencephalomyelitis = IPE) elicited by immunizing old C58 mice with inactivated Ib cells was quantified. Cells used for comparative adoptive protection tests were harvested from the major lymphoid compartments 14 to 15 days after young C58 mice were immunized with inactivated Ib cell preparations. Regression curves were plotted from survival data and the log/sub 10/PD/sub 50/ values were determined. Immune spleen (ISC) and peritoneal cells (IPEC) were significantly more protective against transplanted Ib cells than immune lymph node (ILNC), thymic (ITC), and marrow cells (IMC). In contrast, IPEC and IMC were not protective against IPE and ITC were only marginally protective. ILNC afforded significant protection to transplantable leukemia but were only marginally protective to IPE. When ISC were treated with anti-thy 1.2 serum and complement, protection against transplanted leukemia and IPE was reduced > 99%. When donors of immune lymphoid cells were treated with 12.5 mg of cortisone acetate daily for 2 days before lymphoid cells were harvested, protection against transplanted Ib cells by ISC was reduced by approximately 90% whereas protection against IPE was totally eliminated. Considered together, these results indicate that the protective mechanisms to transplantable leukemia and IPE differ significantly in the same indicator mouse strain.

  19. Regulatory T Cells, a Potent Immunoregulatory Target for CAM Researchers: Modulating Tumor Immunity, Autoimmunity and Alloreactive Immunity (III

    Directory of Open Access Journals (Sweden)

    Aristo Vojdani

    2006-01-01

    Full Text Available Regulatory T (Treg cells are the major arbiter of immune responses, mediating actions through the suppression of inflammatory and destructive immune reactions. Inappropriate Treg cell frequency or functionality potentiates the pathogenesis of myriad diseases with ranging magnitudes of severity. Lack of suppressive capability hinders restraint on immune responses involved in autoimmunity and alloreactivity, while excessive suppressive capacity effectively blocks processes necessary for tumor destruction. Although the etiology of dysfunctional Treg cell populations is under debate, the ramifications, and their mechanisms, are increasingly brought to light in the medical community. Methods that compensate for aberrant immune regulation may not address the underlying complications; however, they hold promise for the alleviation of debilitating immune system-related disorders. The dominant immunoregulatory nature of Treg cells, coupled with recent mechanistic knowledge of natural immunomodulatory compounds, highlights the importance of Treg cells to practitioners and researchers of complementary and alternative medicine (CAM.

  20. Induction of innate immunity by Apergillus fumigatus cell wall polysaccharides is enhanced by the composite presentation of chitin and beta-glucan

    DEFF Research Database (Denmark)

    Dubey, L. K.; Moeller, J. B.; Schlosser, A.;

    2014-01-01

    , TNF-alpha and TSLP production in mice lungs. Selective destruction of chitin or beta-glucan from AIF significantly reduced eosinophil and neutrophil recruitment as well as chitinase activity and cytokine expression by macrophages, indicating the synergistic effect of the cell wall polysaccharides when...... that Aspergillus fumigatus alkali-insoluble cell wall fragments (AIF), composed of chitin linked covalently to beta-glucan, induced enhanced immune responses when compared with individual cell wall polysaccharides. Intranasal administration of AIF induced eosinophil and neutrophil recruitment, chitinase activity...

  1. MenTORing Immunity: mTOR Signaling in the Development and Function of Tissue-Resident Immune Cells.

    Science.gov (United States)

    Jones, Russell G; Pearce, Edward J

    2017-05-16

    Tissue-resident immune cells must balance survival in peripheral tissues with the capacity to respond rapidly upon infection or tissue damage, and in turn couple these responses with intrinsic metabolic control and conditions in the tissue microenvironment. The serine/threonine kinase mammalian/mechanistic target of rapamycin (mTOR) is a central integrator of extracellular and intracellular growth signals and cellular metabolism and plays important roles in both innate and adaptive immune responses. This review discusses the function of mTOR signaling in the differentiation and function of tissue-resident immune cells, with focus on the role of mTOR as a metabolic sensor and its impact on metabolic regulation in innate and adaptive immune cells. We also discuss the impact of metabolic constraints in tissues on immune homeostasis and disease, and how manipulating mTOR activity with drugs such as rapamycin can modulate immunity in these contexts. Copyright © 2017. Published by Elsevier Inc.

  2. Emerging Evidence for Platelets as Immune and Inflammatory Effector Cells

    Directory of Open Access Journals (Sweden)

    Matthew Thomas Rondina

    2014-12-01

    Full Text Available While traditionally recognized for their roles in hemostatic pathways, emerging evidence demonstrates that platelets have previously unrecognized, dynamic roles that span the immune continuum. These newly-recognized platelet functions, including the secretion of immune mediators, interactions with endothelial cells, monocytes, and neutrophils, toll-like receptor (TLR mediated responses, and induction of neutrophil extracellular trap (NET formation, bridge thrombotic and inflammatory pathways and contribute to host defense mechanisms against invading pathogens. In this focused review, we highlight several of these emerging aspects of platelet biology and their implications in clinical infectious syndromes.

  3. Specific Control of Immunity by Regulatory CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    XiaoleiTang; TrevorRFSmith

    2005-01-01

    T lymphocytes with dedicated suppressor function (Treg) play a crucial role in the homeostatic control of immunity in the periphery. Several Treg phenotypes have now been identified in the CD4 and CD8 T cell populations, suggesting their down-regulatory function in both human and animal models of autoimmunity, transplantation and tumor immunity. Here we will focus on the CD8 Treg population and their ability to specifically inhibit a pathogenic autoimmune response. This review will detail the current advances in the knowledge of CD8 Treg in the context of antigen specificity, phenotype, MHC restriction, mechanism of action, and priming. Cellular & Molecular Immunology. 2005;2(1):11-19.

  4. Specific Control of Immunity by Regulatory CD8 T Cells

    Institute of Scientific and Technical Information of China (English)

    Xiaolei Tang; Trevor RF Smith; Vipin Kumar

    2005-01-01

    T lymphocytes with dedicated suppressor function (Treg) play a crucial role in the homeostatic control of immunity in the periphery. Several Treg phenotypes have now been identified in the CD4 and CD8 T cell populations,suggesting their down-regulatory function in both human and animal models of autoimmunity, transplantation and tumor immunity. Here we will focus on the CD8 Treg population and their ability to specifically inhibit a pathogenic autoimmune response. This review will detail the current advances in the knowledge of CD8 Treg in the context of antigen specificity, phenotype, MHC restriction, mechanism of action, and priming.

  5. Self-reported history of vaccination and disease and immunity against hepatitis A, hepatitis B, tetanus, diphtheria and varicella among Spanish military recruits.

    Science.gov (United States)

    Arteaga, Alejandro; Desviat, Pilar Vallejo; Jaqueti, Jeronimo; Santos, Juana; de Miguel, Angel Gil; Garcia, Rodrigo Jiménez

    2010-02-01

    This study aims to evaluate the immune status against hepatitis A, hepatitis B, tetanus, diphtheria and varicella in military recruits and the validity of self-reporting of their disease and vaccination history. A total of 226 participants were studied (mean age, 20.2 years; SD 1.7). 10.4% presented antibodies to hepatitis A, 78.3% to hepatitis B, 94.2% to tetanus, 77.4% to diphtheria and 81.9% to varicella. The relationship between self-reporting of vaccination history and seroprotection showed a high Positive Predictive Value for tetanus (98.8%) and a high Negative Predictive Value for hepatitis A (91%). Hepatitis A vaccination and serology testing for varicella and Hepatitis B on joining the Spanish armed forces are recommended.

  6. Phenotypic characterisation of immune cell infiltrates in testicular germ cell neoplasia

    DEFF Research Database (Denmark)

    Hvarness, Tine; Nielsen, John E; Almstrup, Kristian

    2013-01-01

    and overt seminoma, in comparison to biopsies from infertile men without neoplasia. The composition of immune cells was similar across all the groups studied. Macrophages, CD8(+) and CD45R0(+) T lymphocytes constituted the majority of infiltrates, B lymphocytes were present in an intermediate proportion......Immune cells often infiltrate testicular germ cell neoplasms, including pre-invasive carcinoma in situ (CIS), but the significance of this phenomenon remains unknown. The composition and distribution of infiltrating immune cells were examined by immunohistochemistry in testis samples with CIS...... and very few CD4(+) and FoxP3(+) T cells were detected. HLA-I antigen was more abundant in Sertoli cells in tubules containing CIS than in those with normal spermatogenesis. This study showed a phenotypically comparable composition of infiltrating immune cells independently of the presence of neoplasia...

  7. Tissue specific heterogeneity in effector immune cell response

    Directory of Open Access Journals (Sweden)

    Saba eTufail

    2013-08-01

    Full Text Available Post pathogen invasion, migration of effector T-cell subsets to specific tissue locations is of prime importance for generation of robust immune response. Effector T cells are imprinted with distinct ‘homing codes’ (adhesion molecules and chemokine receptors during activation which regulate their targeted trafficking to specific tissues. Internal cues in the lymph node microenvironment along with external stimuli from food (vitamin A and sunlight (vitamin D3 prime dendritic cells, imprinting them to play centrestage in the induction of tissue tropism in effector T cells. B cells as well, in a manner similar to effector T cells, exhibit tissue tropic migration. In this review, we have focused on the factors regulating the generation and migration of effector T cells to various tissues alongwith giving an overview of tissue tropism in B cells.

  8. Cell wall integrity signaling and innate immunity in plants.

    Science.gov (United States)

    Nühse, Thomas S

    2012-01-01

    All plant pathogens and parasites have had to develop strategies to overcome cell walls in order to access the host's cytoplasm. As a mechanically strong, multi-layered composite exoskeleton, the cell wall not only enables plants to grow tall but also protects them from such attacks. Many plant pathogens employ an arsenal of cell wall degrading enzymes, and it has long been thought that the detection of breaches in wall integrity contributes to the induction of defense. Cell wall fragments are danger-associated molecular patterns or DAMPs that can trigger defense signaling pathways comparable to microbial signals, but the picture is likely to be more complicated. A wide range of defects in cell wall biosynthesis leads to enhanced pathogen resistance. We are beginning to understand the essential role of cell wall integrity surveillance for plant growth, and the connection of processes like cell expansion, plasma membrane-cell wall contact and secondary wall biosynthesis with plant immunity is emerging.

  9. Generation of antigen-specific T cell immunity through T cell receptor gene transfer

    NARCIS (Netherlands)

    Coccoris, Miriam

    2009-01-01

    Cancer cells often escape the attack of immune cells because they originate from self-tissue. Through T cell receptor gene transfer it is possible to equip peripheral T cells with a desired specificity, and this strategy may be useful to generate tumor-specific T cells for the treatment of cancer in

  10. Generation of antigen-specific T cell immunity through T cell receptor gene transfer

    NARCIS (Netherlands)

    Coccoris, Miriam

    2009-01-01

    Cancer cells often escape the attack of immune cells because they originate from self-tissue. Through T cell receptor gene transfer it is possible to equip peripheral T cells with a desired specificity, and this strategy may be useful to generate tumor-specific T cells for the treatment of cancer in

  11. How B cells shape the immune response against Mycobacterium tuberculosis.

    Science.gov (United States)

    Maglione, Paul J; Chan, John

    2009-03-01

    Extensive work illustrating the importance of cellular immune mechanisms for protection against Mycobacterium tuberculosis has largely relegated B-cell biology to an afterthought within the tuberculosis (TB) field. However, recent studies have illustrated that B lymphocytes, through a variety of interactions with the cellular immune response, play previously underappreciated roles in shaping host defense against non-viral intracellular pathogens, including M. tuberculosis. Work in our laboratory has recently shown that, by considering these lymphocytes more broadly within their variety of interactions with cellular immunity, B cells have a significant impact on the outcome of airborne challenge with M. tuberculosis as well as the resultant inflammatory response. In this review, we advocate for a revised view of TB immunology in which roles of cellular and humoral immunity are not mutually exclusive. In the context of our current understanding of host defense against non-viral intracellular infections, we review recent data supporting a more significant role of B cells during M. tuberculosis infection than previously thought.

  12. Human CD8+ T cells mediate protective immunity induced by a human malaria vaccine in human immune system mice.

    Science.gov (United States)

    Li, Xiangming; Huang, Jing; Zhang, Min; Funakoshi, Ryota; Sheetij, Dutta; Spaccapelo, Roberta; Crisanti, Andrea; Nussenzweig, Victor; Nussenzweig, Ruth S; Tsuji, Moriya

    2016-08-31

    A number of studies have shown that CD8+ T cells mediate protective anti-malaria immunity in a mouse model. However, whether human CD8+ T cells play a role in protection against malaria remains unknown. We recently established human immune system (HIS) mice harboring functional human CD8+ T cells (HIS-CD8 mice) by transduction with HLA-A∗0201 and certain human cytokines using recombinant adeno-associated virus-based gene transfer technologies. These HIS-CD8 mice mount a potent, antigen-specific HLA-A∗0201-restricted human CD8+ T-cell response upon immunization with a recombinant adenovirus expressing a human malaria antigen, the Plasmodium falciparum circumsporozoite protein (PfCSP), termed AdPfCSP. In the present study, we challenged AdPfCSP-immunized HIS-CD8 mice with transgenic Plasmodium berghei sporozoites expressing full-length PfCSP and found that AdPfCSP-immunized (but not naïve) mice were protected against subsequent malaria challenge. The level of the HLA-A∗0201-restricted, PfCSP-specific human CD8+ T-cell response was closely correlated with the level of malaria protection. Furthermore, depletion of human CD8+ T cells from AdPfCSP-immunized HIS-CD8 mice almost completely abolished the anti-malaria immune response. Taken together, our data show that human CD8+ T cells mediate protective anti-malaria immunity in vivo.

  13. Microchimeric fetal cells are recruited to maternal kidney following injury and activate collagen type I transcription.

    Science.gov (United States)

    Bou-Gharios, George; Amin, Farhana; Hill, Peter; Nakamura, Hiroyuki; Maxwell, Patrick; Fisk, Nicholas M

    2011-01-01

    Fetal cells enter the maternal circulation from the early first trimester of pregnancy, where they persist in tissue decades later. We investigated in mice whether fetal microchimeric cells (FMCs) can be detected in maternal kidney, and whether they play a role in kidney homeostasis. FMCs were identified in vivo in two models: one an adaptive model following unilateral nephrectomy, the other an injury via unilateral renal ischaemia reperfusion. Both models were carried out in mothers that had been mated with transgenic mice expressing luciferase transgene under the control of collagen type I, and had given birth to either 1 or 3 litters. FMCs were detected by Y-probe fluorescent in situ hybridization (FISH) and bioluminescence, and the cell number quantified by real-time polymerase chain reaction. In the adaptive model, the remaining kidney showed more cells by all 3 parameters compared with the nephrectomized kidney, while ischaemia reperfusion resulted in higher levels of FMC participation in injured compared to contralateral kidneys. Bioluminescence showed that FMCs switch on collagen type I transcription implicating mesenchymal lineage cells. After injury, Y-probe in situ hydridization was found mainly in the tubular epithelial network. Finally, we compared FMCs with bone marrow cells and found similar dynamics but altered distribution within the kidney. We conclude that FMCs (1) are long-term sequelae of pregnancy and (2) are recruited to the kidney as a result of injury or adaptation, where they activate the transcriptional machinery of matrix proteins.

  14. The Effects of Bifidobacterium breve on Immune Mediators and Proteome of HT29 Cells Monolayers

    Directory of Open Access Journals (Sweden)

    Borja Sánchez

    2015-01-01

    Full Text Available The use of beneficial microorganisms, the so-called probiotics, to improve human health is gaining popularity. However, not all of the probiotic strains trigger the same responses and they differ in their interaction with the host. In spite of the limited knowledge on mechanisms of action some of the probiotic effects seem to be exerted through maintenance of the gastrointestinal barrier function and modulation of the immune system. In the present work, we have addressed in vitro the response of the intestinal epithelial cell line HT29 to the strain Bifidobacterium breve IPLA20004. In the array of 84 genes involved in inflammation tested, the expression of 12 was modified by the bifidobacteria. The genes of chemokine CXCL6, the chemokine receptor CCR7, and, specially, the complement component C3 were upregulated. Indeed, HT29 cells cocultivated with B. breve produced significantly higher levels of protein C3a. The proteome of HT29 cells showed increased levels of cytokeratin-8 in the presence of B. breve. Altogether, it seems that B. breve IPLA20004 could favor the recruitment of innate immune cells to the mucosa reinforcing, as well as the physical barrier of the intestinal epithelium.

  15. The Activity of the Neutral Sphingomyelinase Is Important in T Cell Recruitment and Directional Migration

    Directory of Open Access Journals (Sweden)

    Lena Collenburg

    2017-08-01

    Full Text Available Breakdown of sphingomyelin as catalyzed by the activity of sphingomyelinases profoundly affects biophysical properties of cellular membranes which is particularly important with regard to compartmentalization of surface receptors and their signaling relay. As it is activated both upon TCR ligation and co-stimulation in a spatiotemporally controlled manner, the neutral sphingomyelinase (NSM has proven to be important in T cell activation, where it appears to play a particularly important role in cytoskeletal reorganization and cell polarization. Because these are important parameters in directional T cell migration and motility in tissues, we analyzed the role of the NSM in these processes. Pharmacological inhibition of NSM interfered with early lymph node homing of T cells in vivo indicating that the enzyme impacts on endothelial adhesion, transendothelial migration, sensing of chemokine gradients or, at a cellular level, acquisition of a polarized phenotype. NSM inhibition reduced adhesion of T cells to TNF-α/IFN-γ activated, but not resting endothelial cells, most likely via inhibiting high-affinity LFA-1 clustering. NSM activity proved to be highly important in directional T cell motility in response to SDF1-α, indicating that their ability to sense and translate chemokine gradients might be NSM dependent. In fact, pharmacological or genetic NSM ablation interfered with T cell polarization both at an overall morphological level and redistribution of CXCR4 and pERM proteins on endothelial cells or fibronectin, as well as with F-actin polymerization in response to SDF1-α stimulation, indicating that efficient directional perception and signaling relay depend on NSM activity. Altogether, these data support a central role of the NSM in T cell recruitment and migration both under homeostatic and inflamed conditions by regulating polarized redistribution of receptors and their coupling to the cytoskeleton.

  16. Eps8 is recruited to lysosomes and subjected to chaperone-mediated autophagy in cancer cells.

    Science.gov (United States)

    Welsch, Thilo; Younsi, Alexander; Disanza, Andrea; Rodriguez, Jose Antonio; Cuervo, Ana Maria; Scita, Giorgio; Schmidt, Jan

    2010-07-15

    Eps8 controls actin dynamics directly through its barbed end capping and actin-bundling activity, and indirectly by regulating Rac-activation when engaged into a trimeric complex with Eps8-Abi1-Sos1. Recently, Eps8 has been associated with promotion of various solid malignancies, but neither its mechanisms of action nor its regulation in cancer cells have been elucidated. Here, we report a novel association of Eps8 with the late endosomal/lysosomal compartment, which is independent from actin polymerization and specifically occurs in cancer cells. Endogenous Eps8 localized to large vesicular lysosomal structures in metastatic pancreatic cancer cell lines, such as AsPC-1 and Capan-1 that display high Eps8 levels. Additionally, ectopic expression of Eps8 increased the size of lysosomes. Structure-function analysis revealed that the region encompassing the amino acids 184-535 of Eps8 was sufficient to mediate lysosomal recruitment. Notably, this fragment harbors two KFERQ-like motifs required for chaperone-mediated autophagy (CMA). Furthermore, Eps8 co-immunoprecipitated with Hsc70 and LAMP-2, which are key elements for the CMA degradative pathway. Consistently, in vitro, a significant fraction of Eps8 bound to (11.9+/-5.1%) and was incorporated into (5.3+/-6.5%) lysosomes. Additionally, Eps8 binding to lysosomes was competed by other known CMA-substrates. Fluorescence recovery after photobleaching revealed that Eps8 recruitment to the lysosomal membrane was highly dynamic. Collectively, these results indicate that Eps8 in certain human cancer cells specifically localizes to lysosomes, and is directed to CMA. These results open a new field for the investigation of how Eps8 is regulated and contributes to tumor promotion in human cancers.

  17. Immune Cell Targets of Infection at the Tick-Skin Interface during Powassan Virus Transmission.

    Directory of Open Access Journals (Sweden)

    Meghan E Hermance

    Full Text Available Powassan virus (POWV is a tick-borne flavivirus that can result in a severe neuroinvasive disease with 50% of survivors displaying long-term neurological sequelae. Human POWV cases have been documented in Canada, the United States, and Russia. Although the number of reported POWV human cases has increased in the past fifteen years, POWV remains one of the less studied human pathogenic flaviviruses. Ixodes ticks are the vectors for POWV, and the virus is transmitted to a host's skin very early during the tick feeding process. Central to the successful transmission of a tick-borne pathogen are complex interactions between the host immune response and early tick-mediated immunomodulation, all of which initially occur at the skin interface. In our prior work, we examined the cutaneous immune gene expression during the early stages of POWV-infected Ixodes scapularis feeding. The present study serves to further investigate the skin interface by identifying early cell targets of infection at the POWV-infected tick feeding site. An in vivo infection model consisting of POWV-infected ticks feeding on mice for short durations was used in this study. Skin biopsies from the tick feeding sites were harvested at various early time points, enabling us to examine the skin histopathology and detect POWV viral antigen in immune cells present at the tick feeding site. The histopathology from the present study demonstrates that neutrophil and mononuclear cell infiltrates are recruited earlier to the feeding site of a POWV-infected tick versus an uninfected tick. This is the first report demonstrating that macrophages and fibroblasts contain POWV antigens, which suggests that they are early cellular targets of infection at the tick feeding site. These data provide key insights towards defining the complex interactions between the host immune response and early tick-mediated immunomodulation.

  18. Immune-Complexed Adenovirus Induce AIM2-Mediated Pyroptosis in Human Dendritic Cells

    Science.gov (United States)

    Eichholz, Karsten; Bru, Thierry; Tran, Thi Thu Phuong; Fernandes, Paulo; Mennechet, Franck J. D.; Manel, Nicolas; Alves, Paula; Perreau, Matthieu

    2016-01-01

    Human adenoviruses (HAdVs) are nonenveloped proteinaceous particles containing a linear double-stranded DNA genome. HAdVs cause a spectrum of pathologies in all populations regardless of health standards. Following repeat exposure to multiple HAdV types, we develop robust and long-lived humoral and cellular immune responses that provide life-long protection from de novo infections and persistent HAdV. How HAdVs, anti-HAdV antibodies and antigen presenting cells (APCs) interact to influence infection is still incompletely understood. In our study, we used physical, pharmacological, biochemical, fluorescence and electron microscopy, molecular and cell biology approaches to dissect the impact of immune-complexed HAdV (IC-HAdV) on human monocyte-derived dendritic cells (MoDCs). We show that IC-HAdV generate stabilized complexes of ~200 nm that are efficiently internalized by, and aggregate in, MoDCs. By comparing IC-HAdV, IC-empty capsid, IC-Ad2ts1 (a HAdV-C2 impaired in endosomal escape due to a mutation that impacts protease encapsidation) and IC-AdL40Q (a HAdV-C5 impaired in endosomal escape due to a mutation in protein VI), we demonstrate that protein VI-dependent endosomal escape is required for the HAdV genome to engage the DNA pattern recognition receptor AIM2 (absent in melanoma 2). AIM2 engagement induces pyroptotic MoDC death via ASC (apoptosis-associated speck protein containing a caspase activation/recruitment domain) aggregation, inflammasome formation, caspase 1 activation, and IL-1β and gasdermin D (GSDMD) cleavage. Our study provides mechanistic insight into how humoral immunity initiates an innate immune response to HAdV-C5 in human professional APCs. PMID:27636895

  19. Th17 Cells in Immunity and Autoimmunity

    Directory of Open Access Journals (Sweden)

    Simone Kennedy Bedoya

    2013-01-01

    Full Text Available Th17 and IL-17 play important roles in the clearance of extracellular bacterial and fungal infections. However, strong evidence also implicates the Th17 lineage in several autoimmune disorders including multiple sclerosis, psoriasis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, and asthma. The Th17 subset has also been connected with type I diabetes, although whether it plays a role in the pathogenicity of or protection from the disease remains a controversial issue. In this review we have provided a comprehensive overview of Th17 pathogenicity and function, including novel evidence for a protective role of Th17 cells in conjunction with the microbiota gut flora in T1D onset and progression.

  20. Identifying genes that mediate anthracyline toxicity in immune cells

    Directory of Open Access Journals (Sweden)

    Amber eFrick

    2015-04-01

    Full Text Available The role of the immune system in response to chemotherapeutic agents remains elusive. The interpatient variability observed in immune and chemotherapeutic cytotoxic responses is likely, at least in part, due to complex genetic differences. Through the use of a panel of genetically diverse mouse inbred strains, we developed a drug screening platform aimed at identifying genes underlying these chemotherapeutic cytotoxic effects on immune cells. Using genome-wide association studies (GWAS, we identified four genome-wide significant quantitative trait loci (QTL that contributed to the sensitivity of doxorubicin and idarubicin in immune cells. Of particular interest, a locus on chromosome 16 was significantly associated with cell viability following idarubicin administration (p = 5.01x10-8. Within this QTL lies App, which encodes amyloid beta precursor protein. Comparison of dose-response curves verified that T-cells in App knockout mice were more sensitive to idarubicin than those of C57BL/6J control mice (p < 0.05.In conclusion, the cellular screening approach coupled with GWAS led to the identification and subsequent validation of a gene involved in T-cell viability after idarubicin treatment. Previous studies have suggested a role for App in in vitro and in vivo cytotoxicity to anticancer agents; the overexpression of App enhances resistance, while the knockdown of this gene is deleterious to cell viability. Thus, further investigations should include performing mechanistic studies, validating additional genes from the GWAS, including Ppfia1 and Ppfibp1, and ultimately translating the findings to in vivo and human studies.

  1. Mast cells in allergy and autoimmunity: implications for adaptive immunity.

    Science.gov (United States)

    Gregory, Gregory D; Brown, Melissa A

    2006-01-01

    As in the fashion industry, trends in a particular area of scientific investigation often are fleeting but then return with renewed and enthusiastic interest. Studies of mast cell biology are good examples of this. Although dogma once relegated mast cells almost exclusively to roles in pathological inflammation associated with allergic disease, these cells are emerging as important players in a number of other physiological processes. Consequently, they are quickly becoming the newest "trendy" cell, both within and outside the field of immunology. As sources of a large array of pro- and anti-inflammatory mediators, mast cells also express cell surface molecules with defined functions in lymphocyte activation and trafficking. Here, we provide an overview of the traditional and newly appreciated contributions of mast cells to both innate and adaptive immune responses.

  2. NKT cells mediate the recruitment of neutrophils by stimulating epithelial chemokine secretion during colitis.

    Science.gov (United States)

    Huang, Enyu; Liu, Ronghua; Lu, Zhou; Liu, Jiajing; Liu, Xiaoming; Zhang, Dan; Chu, Yiwei

    2016-05-27

    Ulcerative colitis (UC) is a kind of inflammatory bowel diseases characterized by chronic inflammation and ulcer in colon, and UC patients have increased risk of getting colorectal cancer. NKT cells are cells that express both NK cell markers and semi-invariant CD1d-restricted TCRs, can regulate immune responses via secreting a variety of cytokines upon activation. In our research, we found that the NKT cell-deficient CD1d(-/-) mice had relieved colitis in the DSS-induced colitis model. Further investigations revealed that the colon of CD1d(-/-) mice expressed less neutrophil-attracting chemokine CXCL 1, 2 and 3, and had decreased neutrophil infiltration. Infiltrated neutrophils also produced less reactive oxygen species (ROS) and TNF-α, indicating they may cause less epithelial damage. In addition, colitis-associated colorectal cancer was also relieved in CD1d(-/-) mice. During colitis, NKT cells strongly expressed TNF-α, which could stimulate CXCL 1, 2, 3 expressions by the epithelium. In conclusion, NKT cells can regulate colitis via the NKT cell-epithelium-neutrophil axis. Targeting this mechanism may help to improve the therapy of UC and prevent colitis-associated colorectal cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Location and Density of Immune Cells in Precursor Lesions and Cervical Cancer.

    Science.gov (United States)

    Bedoya, Astrid M; Jaramillo, Roberto; Baena, Armando; Castaño, Jorge; Olaya, Natalia; Zea, Arnold H; Herrero, Rolando; Sanchez, Gloria I

    2013-04-01

    Only a small proportion of women infected with Human Papillomavirus (HPV) develop cervical cancer. Host immune response seems to play a role eliminating the viral infection and preventing progression to cancer. Characterization of tumor infiltrating lymphocytes (TILs) in cervical pre-neoplastic lesions and cervical cancer may be helpful to understand the mechanisms that mediate this protection. The aim of this study was to determine if there are differences in the localization and density (cells/mm(2)) of CD8+ T-cells, CD4+ T-cells and Tregs (CD25 + Foxp3+) in cervical pre-neoplastic lesions and cervical cancer. Immunohistochemical analysis of sections of 96 (26 CIN1, 21 CIN2, 25 CIN3, and 24 SCC) samples revealed that regardless of CIN grades, CD8+ T-cells are more abundant than CD4+, CD25+ and Foxp3+ cells in both the stroma and epithelium. There was a higher density of CD8+ cells in the stroma of cervical cancer compared to CIN3 (OR = 4.20, 95% CI 1.2-15), CIN2 (OR = 7.86, 95% CI 1.7-36.4) and CIN1 (OR = 4.25, 95% CI 1.1-17). Studies evaluating whether these cells are recruited before or after cancer progression will be helpful to understand the role of these cells in the natural history of HPV-induced lesions.

  4. Mast cells and basophils in cutaneous immune responses.

    Science.gov (United States)

    Otsuka, A; Kabashima, K

    2015-02-01

    Mast cells and basophils share some functions in common and are generally associated with T helper 2 (Th2) immune responses, but taking basophils as surrogate cells for mast cell research or vice versa for several decades is problematic. Thus far, their in vitro functions have been well studied, but their in vivo functions remained poorly understood. New research tools for their functional analysis in vivo have revealed previously unrecognized roles for mast cells and basophils in several skin disorders. Newly developed mast cell-deficient mice provided evidence that mast cells initiate contact hypersensitivity via activating dendritic cells. In addition, studies using basophil-deficient mice have revealed that basophils were responsible for cutaneous Th2 skewing to haptens and peptide antigens but not to protein antigens. Moreover, human basophils infiltrate different skin lesions and have been implicated in the pathogenesis of skin diseases ranging from atopic dermatitis to autoimmune diseases. In this review, we will discuss the recent advances related to mast cells and basophils in human and murine cutaneous immune responses.

  5. Interleukin 7-engineered stromal cells: a new approach for hastening naive T cell recruitment.

    Science.gov (United States)

    Di Ianni, Mauro; Del Papa, Beatrice; De Ioanni, Maria; Terenzi, Adelmo; Sportoletti, Paolo; Moretti, Lorenzo; Falzetti, Franca; Gaozza, Eugenia; Zei, Tiziana; Spinozzi, Fabrizio; Bagnis, Claude; Mannoni, Patrice; Bonifacio, Elisabetta; Falini, Brunangelo; Martelli, Massimo F; Tabilio, Antonio

    2005-06-01

    In this study we determined whether human stromal cells could be engineered with a retroviral vector carrying the interleukin 7 (IL-7) gene and investigated the effects on T cells in vitro and in vivo in a murine model. Transduced mesenchymal cells strongly express CD90 (98.15%), CD105 (87.6%), and STRO-1 (86.7%). IL-7 production was 16.37 (+/-2 SD) pg/ml, which remained stable for 60 days. In vitro-immunoselected naive T cells maintained the CD45RA+ CD45RO- naive phenotype (4.2 times more than controls) after 7 days of culture with IL-7-engineered stromal cells. The apoptosis rate (4.7%) of the naive T cells cultured with transduced stromal cells overlapped with that of freshly isolated cells. Immunohistological analysis detected stromal cells in bone marrow, spleen, and thymus. Cotransplantation of IL-7-engineered stromal cells with CD34+ cells improved engraftment in terms of CD45+ cells and significantly increased the CD3+ cell count in peripheral blood, bone marrow, and spleen. These data demonstrate the following: (1) human stromal cells can be transduced, generating a normal layer; (2) transduced stromal cells in vitro maintain the naive T cell phenotype; and (3) IL-7-transduced stromal cells in vivo home to lymphoid organs and produce sufficient IL-7 in loco, supporting T cell development in a cotransplantation model. Because of their efficient cytokine production and homing, IL-7-engineered stromal cells might be an ideal vehicle to hasten immunological reconstitution in T cell-depleted hosts.

  6. Inhibition of IL-10 production by maternal antibodies against Group B Streptococcus GAPDH confers immunity to offspring by favoring neutrophil recruitment.

    Directory of Open Access Journals (Sweden)

    Pedro Madureira

    2011-11-01

    Full Text Available Group B Streptococcus (GBS is the leading cause of neonatal pneumonia, septicemia, and meningitis. We have previously shown that in adult mice GBS glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH is an extracellular virulence factor that induces production of the immunosuppressive cytokine interleukin-10 (IL-10 by the host early upon bacterial infection. Here, we investigate whether immunity to neonatal GBS infection could be achieved through maternal vaccination against bacterial GAPDH. Female BALB/c mice were immunized with rGAPDH and the progeny was infected with a lethal inoculum of GBS strains. Neonatal mice born from mothers immunized with rGAPDH were protected against infection with GBS strains, including the ST-17 highly virulent clone. A similar protective effect was observed in newborns passively immunized with anti-rGAPDH IgG antibodies, or F(ab'(2 fragments, indicating that protection achieved with rGAPDH vaccination is independent of opsonophagocytic killing of bacteria. Protection against lethal GBS infection through rGAPDH maternal vaccination was due to neutralization of IL-10 production soon after infection. Consequently, IL-10 deficient (IL-10(-/- mice pups were as resistant to GBS infection as pups born from vaccinated mothers. We observed that protection was correlated with increased neutrophil trafficking to infected organs. Thus, anti-rGAPDH or anti-IL-10R treatment of mice pups before GBS infection resulted in increased neutrophil numbers and lower bacterial load in infected organs, as compared to newborn mice treated with the respective control antibodies. We showed that mothers immunized with rGAPDH produce neutralizing antibodies that are sufficient to decrease IL-10 production and induce neutrophil recruitment into infected tissues in newborn mice. These results uncover a novel mechanism for GBS virulence in a neonatal host that could be neutralized by vaccination or immunotherapy. As GBS GAPDH is a

  7. D-polyglutamine amyloid recruits L-polyglutamine monomers and kills cells

    Science.gov (United States)

    Kar, Karunakar; Arduini, Irene; Drombosky, Kenneth W.; van der Wel, Patrick C. A.; Wetzel, Ronald

    2014-01-01

    Polyglutamine (polyQ) amyloid fibrils are observed in disease tissue and have been implicated as toxic agents responsible for neurodegeneration in expanded CAG repeat diseases like Huntington’s disease (HD). Despite intensive efforts, the mechanism of amyloid toxicity remains unknown. As a novel approach to probing polyQ toxicity, we investigate here how some cellular and physical properties of polyQ amyloid vary with the chirality of the glutamine residues in the polyQ. We challenged PC12 cells with small amyloid fibrils composed of either L- or D-polyQ peptides and found that D-fibrils are as cytotoxic as L-fibrils. We also found using fluorescence microscopy that both aggregates effectively seed the aggregation of cell-produced L-polyQ proteins, suggesting a surprising lack of stereochemical restriction in seeded elongation of polyQ amyloid. To investigate this effect further, we studied chemically synthesized D- and L-polyQ in vitro. We found that, as expected, D-polyQ monomers are not recognized by proteins that recognize L-polyQ monomers. However, amyloid fibrils prepared from D-polyQ peptides can efficiently seed the aggregation of L-polyQ monomers in vitro, and vice versa. This result is consistent with our cell results on polyQ recruitment, but is inconsistent with previous literature reports on the chiral specificity of amyloid seeding. This chiral cross-seeding can be rationalized by a model for seeded elongation featuring a “rippled β-sheet” interface between seed fibril and docked monomers of opposite chirality. The lack of chiral discrimination in polyQ amyloid cytotoxicity is consistent with several toxicity mechanisms, including recruitment of cellular polyQ proteins. PMID:24291210

  8. Regulatory T cells and the immune pathogenesis of prenatal infection.

    Science.gov (United States)

    Rowe, Jared H; Ertelt, James M; Xin, Lijun; Way, Sing Sing

    2013-12-01

    Pregnancy in placental mammals offers exceptional comprehensive benefits of in utero protection, nutrition, and metabolic waste elimination for the developing fetus. However, these benefits also require durable strategies to mitigate maternal rejection of fetal tissues expressing foreign paternal antigens. Since the initial postulate of expanded maternal immune tolerance by Sir Peter Medawar 60 years ago, an amazingly elaborate assortment of molecular and cellular modifications acting both locally at the maternal-placental interface and systemically have been shown to silence potentially detrimental maternal immune responses. In turn, simultaneously maintaining host defense against the infinite array of potential pathogens during pregnancy is equally important. Fortunately, resistance against most infections is preserved seamlessly throughout gestation. On the other hand, recent studies on pathogens with unique predisposition for prenatal infections have uncovered distinctive holes in host defense associated with the reproductive process. Using these infections to probe the response during pregnancy, the immune suppressive regulatory subset of maternal CD4 T cells has been increasingly shown to dictate the inter-workings between prenatal infection susceptibility and pathogenesis of ensuing pregnancy complications. Herein, the recent literature suggesting a necessity for maternal regulatory T cells (Tregs) in pregnancy-induced immunological shifts that sustain fetal tolerance is reviewed. Additional discussion is focused on how expansion of maternal Treg suppression may become exploited by pathogens that cause prenatal infections and the perilous potential of infection-induced immune activation that may mitigate fetal tolerance and inadvertently inject hostility into the protective in utero environment.

  9. Leukocyte TLR5 deficiency inhibits atherosclerosis by reduced macrophage recruitment and defective T-cell responsiveness

    Science.gov (United States)

    Ellenbroek, Guilielmus H.J.M.; van Puijvelde, Gijs H.M.; Anas, Adam A.; Bot, Martine; Asbach, Miriam; Schoneveld, Arjan; van Santbrink, Peter J.; Foks, Amanda C.; Timmers, Leo; Doevendans, Pieter A.; Pasterkamp, Gerard; Hoefer, Imo E.; van der Poll, Tom; Kuiper, Johan; de Jager, Saskia C.A.

    2017-01-01

    Toll-like receptors (TLR) provide a critical link between innate and adaptive immunity, both important players in atherosclerosis. Since evidence for the role of TLR5 is lacking, we aimed to establish this in the immune axis of atherosclerosis. We assessed the effect of the TLR5-specific ligand Flagellin on macrophage maturation and T-cell polarisation. Next, we generated TLR5−/−LDLr−/− chimeras to study the effect of hematopoietic TLR5 deficiency on atherosclerosis formation. Flagellin stimulation did not influence wildtype or TLR5−/− macrophage maturation. Only in wildtype macrophages, Flagellin exposure increased MCP-1 and IL6 expression. Flagellin alone reduced T-helper 1 proliferation, which was completely overruled in the presence of T-cell receptor activation. In vivo, hematopoietic TLR5 deficiency attenuated atherosclerotic lesion formation by ≈25% (1030*103 ± 63*103 vs. 792*103 ± 61*103 μm2; p = 0.013) and decreased macrophage area (81.3 ± 12.0 vs. 44.2 ± 6.6 μm2; p = 0.011). In TLR5−/− chimeric mice, we observed lower IL6 plasma levels (36.4 ± 5.6 vs. 15.1 ± 2.2 pg/mL; p = 0.003), lower (activated) splenic CD4+ T-cell content (32.3 ± 2.1 vs. 21.0 ± 1.2%; p = 0.0018), accompanied by impaired T-cell proliferative responses. In conclusion, hematopoietic TLR5 deficiency inhibits atherosclerotic lesion formation by attenuated macrophage accumulation and defective T-cell responsiveness. PMID:28202909

  10. PB1 as a potential target for increasing the breadth of T-cell mediated immunity to Influenza A

    DEFF Research Database (Denmark)

    Uddbäck, Ida E M; Steffensen, Maria A; Pedersen, Sara R;

    2016-01-01

    not as efficiently protected against influenza A challenge as similarly NP-vaccinated animals. The reason for this is not a difference in the quality of the primed cells, nor in functional avidity. However, under similar conditions of immunization fewer PB1-specific cells were recruited to the airways, and surface...... in the dominant NP366 epitope were not efficiently protected. To address this problem, we envision the use of a cocktail of adenovectors targeting different internal proteins of influenza A virus. Consequently, we investigated the possibility of using PB1 as a target for an adenovector-based vaccine against...

  11. Processing of CXCL12 impedes the recruitment of endothelial progenitor cells in diabetic wound healing.

    Science.gov (United States)

    Feng, Guang; Hao, Daifeng; Chai, Jiake

    2014-11-01

    High blood sugar levels result in defective wound healing processes in diabetic patients. Endothelial progenitor cells (EPCs) play an important role in vasculogenesis, and thereby contribute to reconstitution of the microcirculation and healing. This study aimed to determine the possible mechanism by which the numbers of circulating EPCs are regulated in response to tissue wounding. In the streptozotocin-induced diabetic mouse model, we found that phagocytes activated by local inflammatory cytokines in the wound interfere with the mobilization and recruitment of EPCs to the lesion area. Specifically, the activated macrophages inactivate CXCL12, the major chemokine for EPC recruitment, via matrix metalloproteinases (MMPs), and thereby prevent local chemotaxis and subsequent homing of EPCs to the wound. The wound healing process is delayed by local administration of inflammatory cytokines, and its rate is increased by MMP inhibitors. This study indicates that local inhibition of MMPs is beneficial for regeneration of damaged vessels, and may explain poor wound healing in diabetic patients, thus demonstrating its potential utility as a local treatment therapy to promote diabetic wound healing.

  12. Direct interaction studies between Aspergillus fumigatus and Human immune cells; what have we learned about pathogenicity and host immunity?

    Directory of Open Access Journals (Sweden)

    Charles Oliver Morton

    2012-12-01

    Full Text Available Invasive aspergillosis is a significant threat to health and is a major cause of mortality in immunocompromised individuals. Understanding the interaction between the fungus and the immune system is important in determining how the immunocompetent host remain disease free. Several studies examining the direct interaction between Aspergillus fumigatus and purified innate immune cells have been conducted to measure the responses of both the host cells and the pathogen. It has been revealed that innate immune cells have different modes of action ranging from effective fungal killing by neutrophils to the less aggressive response of dendritic cells. Natural-killer cells do not phagocytose the fungus unlike the other innate immune cells mentioned but appear to mediate their antifungal effect through the release of gamma interferon. Transcriptional analysis of A. fumigatus interacting with these cells has indicated that it can adapt to the harsh microenvironment of the phagosome and produces toxins, ribotoxin and gliotoxin, that can induce cell death in the majority of innate immune cells. These data point towards potential novel antifungal treatments including the use of innate immune cells as antifungal vaccines.

  13. Mesenchymal stem cell recruitment by stromal derived factor-1-delivery systems based on chitosan/poly(γ-glutamic acid polyelectrolyte complexes

    Directory of Open Access Journals (Sweden)

    RM Gonçalves

    2012-04-01

    Full Text Available Human mesenchymal stem cells (hMSCs have an enormous potential for tissue engineering and cell-based therapies. With a potential of differentiation into multiple lineages and immune-suppression, these cells play a key role in tissue remodelling and regeneration.Here a method of hMSC recruitment is described, based on the incorporation of a chemokine in Chitosan (Ch/Poly(γ-glutamic acid (γ-PGA complexes. Ch is a non-toxic, cationic polysaccharide widely investigated. γ-PGA is a hydrophilic, non-toxic, biodegradable and negatively charged poly-amino acid. Ch and γ-PGA, being oppositely charged, can be combined through electrostatic interactions. These biocompatible structures can be used as carriers for active substances and can be easily modulated in order to control the delivery of drugs, proteins, DNA, etc.Using the layer-by-layer method, Ch and γ-PGA were assembled into polyelectrolyte multilayers films (PEMs with thickness of 120 nm. The chemokine stromal-derived factor-1 (SDF-1 was incorporated in these complexes and was continuously released during 120 h. The method of SDF-1 incorporation is of crucial importance for polymers assembly into PEMs and for the release kinetics of this chemokine. The Ch/γ-PGA PEMs with SDF-1 were able to recruit hMSCs, increasing the cell migration up to 6 fold to a maximum of 16.2 ± 4.9 cells/mm2. The controlled release of SDF-1 would be of great therapeutic value in the process of hMSC homing to injured tissues. This is the first study suggesting Ch/γ-PGA PEMs as SDF-1 reservoirs to recruit hMSCs, describing an efficient method of chemokine incorporation that allows a sustained released up to 5 days and that can be easily scaled-up.

  14. The responses of immune cells to iron oxide nanoparticles.

    Science.gov (United States)

    Xu, Yaolin; Sherwood, Jennifer A; Lackey, Kimberly H; Qin, Ying; Bao, Yuping

    2016-04-01

    Immune cells play an important role in recognizing and removing foreign objects, such as nanoparticles. Among various parameters, surface coatings of nanoparticles are the first contact with biological system, which critically affect nanoparticle interactions. Here, surface coating effects on nanoparticle cellular uptake, toxicity and ability to trigger immune response were evaluated on a human monocyte cell line using iron oxide nanoparticles. The cells were treated with nanoparticles of three types of coatings (negatively charged polyacrylic acid, positively charged polyethylenimine and neutral polyethylene glycol). The cells were treated at various nanoparticle concentrations (5, 10, 20, 30, 50 μg ml(-1) or 2, 4, 8, 12, 20 μg cm(-2)) with 6 h incubation or treated at a nanoparticle concentration of 50 μg ml(-1) (20 μg cm(-2)) at different incubation times (6, 12, 24, 48 or 72 h). Cell viability over 80% was observed for all nanoparticle treatment experiments, regardless of surface coatings, nanoparticle concentrations and incubation times. The much lower cell viability for cells treated with free ligands (e.g. ~10% for polyethylenimine) suggested that the surface coatings were tightly attached to the nanoparticle surfaces. The immune responses of cells to nanoparticles were evaluated by quantifying the expression of toll-like receptor 2 and tumor necrosis factor-α. The expression of tumor necrosis factor-α and toll-like receptor 2 were not significant in any case of the surface coatings, nanoparticle concentrations and incubation times. These results provide useful information to select nanoparticle surface coatings for biological and biomedical applications.

  15. Actin and dynamin recruitment and the lack thereof at exo- and endocytotic sites in PC12 cells.

    Science.gov (United States)

    Felmy, Felix

    2009-06-01

    Protein recruitment during endocytosis is well characterized in fibroblasts. Since fibroblasts do not engage in regulated exocytosis, only information about protein recruitment during constitutive endocytosis is provided. Furthermore, the cortical actin of fibroblasts is characterized by stress fibers rather than a thick cortical meshwork. A cell model, which differs in these features, could provide insight into the heterogeneity of protein recruitment to constitutive and exocytosis coupled endocytotic areas. Therefore, this study investigates the sequence of protein recruitment in PC12 cells, a well documented exocytotic cell model with thick actin cortex. Using real time total-internal-reflection fluorescence microscopy it was found that at the plasma membrane steady, but not transient, dynamin-1-EGFP or -mCherry fluorescence spots that rapidly dimmed coincided with markers for constitutive endocytotic such as clathrin-LC-dsRed and transferrin-receptor-pHluorin. Clathrin-LC-dsRed and dynamin-1-EGFP were further used to determine the temporal sequence of protein recruitment to areas of constitutive endocytosis. mCherry- and EGFP-beta-actin, Arp-3-EGFP and EGFP-mAbp1 were slowly recruited before the dynamin-1-mCherry fluorescence dimmed, but their fluorescence peaked after the loss of clathrin-LC-dsRed commenced. Furthermore, mCherry-beta-actin fluorescence increased before exocytosis, indicating redistribution prior to release. Also, no average dynamin-1-mCherry recruitment was observed within 50 s to regions of exocytosis marked by NPY-mGFP. This indicates that the temporal-spatial coupling between regulated exo-and endocytosis is rather limited in PC12 cells. Furthermore, the time course of the protein recruitment to constitutive endocytotic sites might depend on the subcellular morphology such as the size of the actin cortex.

  16. Immune TB Antibody Phage Display Library as a Tool To Study B Cell Immunity in TB Infections.

    Science.gov (United States)

    Hamidon, Nurul Hamizah; Suraiya, Siti; Sarmiento, Maria E; Acosta, Armando; Norazmi, Mohd Nor; Lim, Theam Soon

    2017-09-07

    B cells and in particular antibodies has always played second fiddle to cellular immunity in regard to tuberculosis (TB). However, recent studies has helped position humoral immunity especially antibodies back into the foray in relation to TB immunity. Therefore, the ability to correlate the natural antibody responses of infected individuals toward TB antigens would help strengthen this concept. Phage display is an intriguing approach that can be utilized to study antibody-mediated responses against a particular infection via harvesting the B cell repertoire from infected individuals. The development of disease-specific antibody libraries or immune libraries is useful to better understand antibody-mediated immune responses against specific disease antigens. This study describes the generation of an immune single-chain variable fragment (scFv) library derived from TB-infected individuals. The immune library with an estimated diversity of 10(9) independent clones was then applied for the identification of monoclonal antibodies against Mycobacterium tuberculosis α-crystalline as a model antigen. Biopanning of the library isolated three monoclonal antibodies with unique gene usage. This strengthens the role of antibodies in TB immunity in addition to the role played by cellular immunity. The developed library can be applied against other TB antigens and aid antibody-derived TB immunity studies in the future.

  17. Assessing humoral and cell-mediated immune response in Hawaiian green turtles, Chelonia mydas

    Science.gov (United States)

    Work, T.M.; Balazs, G.H.; Rameyer, R.A.; Chang, S.P.; Berestecky, J.

    2000-01-01

    Seven immature green turtles, Chelonia mydas, captured from Kaneohe Bay on the island of Oahu were used to evaluate methods for assessing their immune response. Two turtles each were immunized intramuscularly with egg white lysozyme (EWL) in Freunda??s complete adjuvant, Gerbu, or ISA-70; a seventh turtle was immunized with saline only and served as a control. Humoral immune response was measured with an indirect enzyme linked immunosorbent assay (ELISA). Cell-mediated immune response was measured using in vitro cell proliferation assays (CPA) using whole blood or peripheral blood mononuclear cells (PBM) cultured with concanavalin A (ConA), phytohaemagglutinin (PHA), or soluble egg EWL antigen. All turtles, except for one immunized with Gerbu and the control, produced a detectable humoral immune response by 6 weeks which persisted for at least 14 weeks after a single immunization. All turtles produced an anamnestic humoral immune response after secondary immunization. Antigen specific cell-mediated immune response in PBM was seen in all turtles either after primary or secondary immunization, but it was not as consistent as humoral immune response; antigen specific cell-mediated immune response in whole blood was rarely seen. Mononuclear cells had significantly higher stimulation indices than whole blood regardless of adjuvant, however, results with whole blood had lower variability. Both Gerbu and ISA-70 appeared to potentiate the cell-mediated immune response when PBM or whole blood were cultured with PHA. This is the first time cell proliferation assays have been compared between whole blood and PBM for reptiles. This is also the first demonstration of antigen specific cell-mediated response in reptiles. Cell proliferation assays allowed us to evaluate the cell-mediated immune response of green turtles. However, CPA may be less reliable than ELISA for detecting antigen specific immune response. Either of the three adjuvants appears suitable to safely elicit a

  18. Macrophage Recruitment and Epithelial Repair Following Hair Cell Injury in the Mouse Utricle

    Directory of Open Access Journals (Sweden)

    Tejbeer eKaur

    2015-04-01

    Full Text Available The sensory organs of the inner ear possess resident populations of macrophages, but the function of those cells is poorly understood. In many tissues, macrophages participate in the removal of cellular debris after injury and can also promote tissue repair. The present study examined injury-evoked macrophage activity in the mouse utricle. Experiments used transgenic mice in which the gene for the human diphtheria toxin receptor (huDTR was inserted under regulation of the Pou4f3 promoter. Hair cells in such mice can be selectively lesioned by systemic treatment with diphtheria toxin (DT. In order to visualize macrophages, Pou4f3-huDTR mice were crossed with a second transgenic line, in which one or both copies of the gene for the fractalkine receptor CX3CR1 were replaced with a gene for GFP. Such mice expressed GFP in all macrophages, and mice that were CX3CR1GFP/GFP lacked the necessary receptor for fractalkine signaling. Treatment with DT resulted in the death of ~70% of utricular hair cells within seven days, which was accompanied by increased numbers of macrophages within the utricular sensory epithelium. Many of these macrophages appeared to be actively engulfing hair cell debris, indicating that macrophages participate in the process of ‘corpse removal’ in the mammalian vestibular organs. However, we observed no apparent differences in injury-evoked macrophage numbers in the utricles of CX3CR1+/GFP mice vs. CX3CR1GFP/GFP mice, suggesting that fractalkine signaling is not necessary for macrophage recruitment in these sensory organs. Finally, we found that repair of sensory epithelia at short times after DT-induced hair cell lesions was mediated by relatively thin cables of F-actin. After 56 days recovery, however, all cell-cell junctions were characterized by very thick actin cables.

  19. RACK1 regulates mesenchymal cell recruitment during sexual and asexual reproduction of budding tunicates.

    Science.gov (United States)

    Tatzuke, Yuki; Sunanaga, Takeshi; Fujiwara, Shigeki; Kawamura, Kaz

    2012-08-15

    A homolog of receptor for activated protein kinase C1 (RACK1) was cloned from the budding tunicate Polyandrocarpa misakiensis. By RT-PCR and in situ hybridization analyses, PmRACK1 showed biphasic gene expression during asexual and sexual reproduction. In developing buds, the signal was exclusively observed in the multipotent atrial epithelium and undifferentiated mesenchymal cells that contributed to morphogenesis by the mesenchymal-epithelial transition (MET). In juvenile zooids, the signal was first observable in germline precursor cells that arose as mesenchymal cell aggregated in the ventral hemocoel. In mature zooids, the germinal epithelium in the ovary and the pharynx were the most heavily stained parts. GFP reporter assay indicated that the ovarian expression of PmRACK1 was constitutive from germline precursor cells to oocytes. To elucidate the in vivo function of PmRACK1, RNA interference was challenged. When growing buds were incubated with 5 nmol/mL siRNA, most mesenchymal cells remained round and appeared to have no interactions with the extracellular matrix (ECM), causing lower activity of MET without any apparent effects on cell proliferation. The resultant zooids became growth-deficient. The dwarf zooids did not form buds or mature gonads. Prior to RNAi, buds were treated with human BMP4 that could induce PmRACK1 expression, which resulted in MET activity. We conclude that in P. misakiensis, PmRACK1 plays roles in mesenchymal cell recruitment during formation of somatic and gonad tissues, which contributes to zooidal growth and sexual and asexual reproduction.

  20. Genomic Analysis of Immune Cell Infiltrates Across 11 Tumor Types.

    Science.gov (United States)

    Iglesia, Michael D; Parker, Joel S; Hoadley, Katherine A; Serody, Jonathan S; Perou, Charles M; Vincent, Benjamin G

    2016-11-01

    Immune infiltration of the tumor microenvironment has been associated with improved survival for some patients with solid tumors. The precise makeup and prognostic relevance of immune infiltrates across a broad spectrum of tumors remain unclear. Using mRNA sequencing data from The Cancer Genome Atlas (TCGA) from 11 tumor types representing 3485 tumors, we evaluated lymphocyte and macrophage gene expression by tissue type and by genomic subtypes defined within and across tumor tissue of origin (Cox proportional hazards, Pearson correlation). We investigated clonal diversity of B-cell infiltrates through calculating B-cell receptor (BCR) repertoire sequence diversity. All statistical tests were two-sided. High expression of T-cell and B-cell signatures predicted improved overall survival across many tumor types including breast, lung, and melanoma (breast CD8_T_Cells hazard ratio [HR] = 0.36, 95% confidence interval [CI] = 0.16 to 0.81, P = .01; lung adenocarcinoma B_Cell_60gene HR = 0.71, 95% CI = 0.58 to 0.87, P = 7.80E-04; melanoma LCK HR = 0.86, 95% CI = 0.79 to 0.94, P = 6.75E-04). Macrophage signatures predicted worse survival in GBM, as did B-cell signatures in renal tumors (Glioblastoma Multiforme [GBM]: macrophages HR = 1.62, 95% CI = 1.17 to 2.26, P = .004; renal: B_Cell_60gene HR = 1.17, 95% CI = 1.04 to 1.32, P = .009). BCR diversity was associated with survival beyond gene segment expression in melanoma (HR = 2.67, 95% CI = 1.32 to 5.40, P = .02) and renal cell carcinoma (HR = 0.36, 95% CI = 0.15 to 0.87, P = .006). These data support existing studies suggesting that in diverse tissue types, heterogeneous immune infiltrates are present and typically portend an improved prognosis. In some tumor types, BCR diversity was also associated with survival. Quantitative genomic signatures of immune cells warrant further testing as prognostic markers and potential biomarkers of response to cancer immunotherapy.

  1. HepG2 cells acquire stem cell-like characteristics after immune cell stimulation.

    Science.gov (United States)

    Wang, Hang; Yang, Miqing; Lin, Ling; Ren, Hongzhen; Lin, Chaotong; Lin, Suling; Shen, Guoying; Ji, Binfeng; Meng, Chun

    2016-02-01

    The presence of cancer stem cells (CSCs) is currently regarded as one of the main culprits of tumor formation and therapy failure. It is known that chronic inflammation is associated with CSCs, but it is not clear yet how inflammation affects the development of CSCs. In the present study we aimed to examine the relationship between cancer cell stimulation mediated by immune cells and the acquisition of a CSC-like phenotype. Cancer cells derived from single hepatocarcinoma HepG2 cells were treated with mouse splenic B cells (MSBCs) and mouse peritoneal macrophage cells (MPMCs), respectively. The stem cell-like characteristics of the resulting HepG2 cells (MSBC-HepG2 and MPMC-HepG2) were evaluated using different assays, including biomarker assays, in vitro tumoroid and colony forming assays, in vivo tumor forming assays and signal transduction pathway activation assays. Various stemness characteristics of HepG2 cells, including self-renewal, proliferation, chemoresistance and tumorigenicity were evaluated. The expression levels of stemness-related genes and its encoded proteins in the MSBC-HepG2 and MPMC-HepG2 cells were assessed using RT-PCR and FACS analyses. We found that MSBC-HepG2 and MPMC-HepG2 cells possess hepatic CSC properties, including persistent self-renewal, extensive proliferation, drug resistance, high tumorigenic capacity and over-expression of CSC-related genes and proteins (i.e., EpCAM, ALDH, CD133 and CD44), compared to the parental cells. We also found that 1x10(3) MSBC-HepG2 and MPMC-HepG2 cells were able to form tumors in NOD/SCID mice and that the Notch and SHH signaling pathways were highly activated in MSBC-HepG2 cells. We conclude that the immune system may have a double-edge effect on cancer development. On one hand, immune cells such as B lymphocytes and macrophages may recognize, attack and eliminate cancer cells, whereas on the other hand, they may promote a subset of cancer cells to acquire stem cell-like characteristics.

  2. Suppression of cell-mediated immunity by misonidazole

    Energy Technology Data Exchange (ETDEWEB)

    Rockwell, S.; Neaderland, M.H. (Yale Univ., New Haven, CT (USA). School of Medicine)

    1982-08-01

    The data presented in this report demonstrate that single treatments with large doses of misonidazole (l mg/g) produce significant inhibition of delayed hypersensitivity to DNFB. Contact sensitivity to DNFB is generally considered to be a cell-mediated immune response (Asherson and Ptak 1968, Moorhead 1978, Phanuphak et al. 1974, Zembala and Asherson 1973). The authors' histological observations and the lack of ear swelling in the nude mice support this interpretation.

  3. Mineralocorticoid Receptors in Immune Cells; Emerging Role in Cardiovascular Disease

    OpenAIRE

    Bene, Nicholas C.; Alcaide, Pilar; Wortis, Henry H.; Jaffe, Iris Z.

    2014-01-01

    Mineralocorticoid receptors (MR) contribute to the pathophysiology of hypertension and cardiovascular disease in humans. As such, MR antagonists improve cardiovascular outcomes but the molecular mechanisms remain unclear. The actions of the MR in the kidney to increase blood pressure are well known, but the recent identification of MRs in immune cells has led to novel discoveries in the pathogenesis of cardiovascular disease that are reviewed here. MR regulates macrophage activation to the pr...

  4. Downregulation of CD4+CD25+ regulatory T cells may underlie enhanced Th1 immunity caused by immunization with activated autologous T cells

    Institute of Scientific and Technical Information of China (English)

    Qi Cao; Dangsheng Li; Ningli Li; Li Wang; Fang Du; Huiming Sheng; Yan Zhang; Juanjuan Wu; Baihua Shen; Tianwei Shen; Jingwu Zhang

    2007-01-01

    Regulatory T cells (Treg) play important roles in immune system homeostasis, and may also be involved in tumor immunotolerance by suppressing Thl immune response which is involved in anti-tumor immunity. We have previously reported that immunization with attenuated activated autologous T cells leads to enhanced anti-tumor immunity and upregulated Thl responses in vivo. However, the underlying molecular mechanisms are not well understood. Here we show that Treg function was significantly downregulated in mice that received immunization of attenuated activated autologous T cells. We found that Foxp3 expression decreased in CD4+CD25+ T cells from the immunized mice. Moreover, CD4+CD25+Foxp3+ Treg obtained from immunized mice exhibited diminished immunosuppression ability compared to those from naive mice. Further analysis showed that the serum of immunized mice contains a high level of anti-CD25 antibody (about 30 ng/ml,/K0.01 vs controls). Consistent with a role of anti-CD25 response in the down-regulation of Treg, adoptive transfer of serum from immunized mice to naive mice led to a significant decrease in Treg population and function in recipient mice. The triggering of anti-CD25 response in immunized mice can be explained by the fact that CD25 was induced to a high level in the ConA activated autologous T cells used for immunization. Our results demonstrate for the first time that immunization with attenuated activated autologous T cells evokes anti-CD25 antibody production, which leads to impeded CD4+CD25+Foxp3+ Treg expansion and function in vivo. We suggest that dampened Treg function likely contributes to enhanced Thl response in immunized mice and is at least part of the mechanism underlying the boosted anti-tumor immunity.

  5. Glycation of extracellular matrix proteins impairs migration of immune cells.

    Science.gov (United States)

    Haucke, Elisa; Navarrete-Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-01-01

    The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.

  6. FOXA and master transcription factors recruit Mediator and Cohesin to the core transcriptional regulatory circuitry of cancer cells

    Science.gov (United States)

    Fournier, Michèle; Bourriquen, Gaëlle; Lamaze, Fabien C.; Côté, Maxime C.; Fournier, Éric; Joly-Beauparlant, Charles; Caron, Vicky; Gobeil, Stéphane; Droit, Arnaud; Bilodeau, Steve

    2016-10-01

    Controlling the transcriptional program is essential to maintain the identity and the biological functions of a cell. The Mediator and Cohesin complexes have been established as central cofactors controlling the transcriptional program in normal cells. However, the distribution, recruitment and importance of these complexes in cancer cells have not been fully investigated. Here we show that FOXA and master transcription factors are part of the core transcriptional regulatory circuitry of cancer cells and are essential to recruit M ediator and Cohesin. Indeed, Mediator and Cohesin occupied the enhancer and promoter regions of actively transcribed genes and maintained the proliferation and colony forming potential. Through integration of publically available ChIP-Seq datasets, we predicted the core transcriptional regulatory circuitry of each cancer cell. Unexpectedly, for all cells investigated, the pioneer transcription factors FOXA1 and/or FOXA2 were identified in addition to cell-specific master transcription factors. Loss of both types of transcription factors phenocopied the loss of Mediator and Cohesin. Lastly, the master and pioneer transcription factors were essential to recruit Mediator and Cohesin to regulatory regions of actively transcribed genes. Our study proposes that maintenance of the cancer cell state is dependent on recruitment of Mediator and Cohesin through FOXA and master transcription factors.

  7. FOXA and master transcription factors recruit Mediator and Cohesin to the core transcriptional regulatory circuitry of cancer cells.

    Science.gov (United States)

    Fournier, Michèle; Bourriquen, Gaëlle; Lamaze, Fabien C; Côté, Maxime C; Fournier, Éric; Joly-Beauparlant, Charles; Caron, Vicky; Gobeil, Stéphane; Droit, Arnaud; Bilodeau, Steve

    2016-10-14

    Controlling the transcriptional program is essential to maintain the identity and the biological functions of a cell. The Mediator and Cohesin complexes have been established as central cofactors controlling the transcriptional program in normal cells. However, the distribution, recruitment and importance of these complexes in cancer cells have not been fully investigated. Here we show that FOXA and master transcription factors are part of the core transcriptional regulatory circuitry of cancer cells and are essential to recruit M ediator and Cohesin. Indeed, Mediator and Cohesin occupied the enhancer and promoter regions of actively transcribed genes and maintained the proliferation and colony forming potential. Through integration of publically available ChIP-Seq datasets, we predicted the core transcriptional regulatory circuitry of each cancer cell. Unexpectedly, for all cells investigated, the pioneer transcription factors FOXA1 and/or FOXA2 were identified in addition to cell-specific master transcription factors. Loss of both types of transcription factors phenocopied the loss of Mediator and Cohesin. Lastly, the master and pioneer transcription factors were essential to recruit Mediator and Cohesin to regulatory regions of actively transcribed genes. Our study proposes that maintenance of the cancer cell state is dependent on recruitment of Mediator and Cohesin through FOXA and master transcription factors.

  8. FOXA and master transcription factors recruit Mediator and Cohesin to the core transcriptional regulatory circuitry of cancer cells

    Science.gov (United States)

    Fournier, Michèle; Bourriquen, Gaëlle; Lamaze, Fabien C.; Côté, Maxime C.; Fournier, Éric; Joly-Beauparlant, Charles; Caron, Vicky; Gobeil, Stéphane; Droit, Arnaud; Bilodeau, Steve

    2016-01-01

    Controlling the transcriptional program is essential to maintain the identity and the biological functions of a cell. The Mediator and Cohesin complexes have been established as central cofactors controlling the transcriptional program in normal cells. However, the distribution, recruitment and importance of these complexes in cancer cells have not been fully investigated. Here we show that FOXA and master transcription factors are part of the core transcriptional regulatory circuitry of cancer cells and are essential to recruit M ediator and Cohesin. Indeed, Mediator and Cohesin occupied the enhancer and promoter regions of actively transcribed genes and maintained the proliferation and colony forming potential. Through integration of publically available ChIP-Seq datasets, we predicted the core transcriptional regulatory circuitry of each cancer cell. Unexpectedly, for all cells investigated, the pioneer transcription factors FOXA1 and/or FOXA2 were identified in addition to cell-specific master transcription factors. Loss of both types of transcription factors phenocopied the loss of Mediator and Cohesin. Lastly, the master and pioneer transcription factors were essential to recruit Mediator and Cohesin to regulatory regions of actively transcribed genes. Our study proposes that maintenance of the cancer cell state is dependent on recruitment of Mediator and Cohesin through FOXA and master transcription factors. PMID:27739523

  9. Wolbachia surface protein induces innate immune responses in mosquito cells

    Directory of Open Access Journals (Sweden)

    Pinto Sofia B

    2012-01-01

    Full Text Available Abstract Background Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. Results Here we show that recombinant Wolbachia Surface Protein (WSP stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. Conclusions We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae while a milder elicitor in a naturally-infected species (Aedes albopictus. Since the WSP of a mosquito non-native (nematode Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus.

  10. Improved cognitive and memory abilities in a patient with Alzheimer's disease treated with activated immune cells: Immune cell therapy may benefit more AD patients.

    Science.gov (United States)

    Laumbacher, B; Fellerhoff-Loesch, B; Wank, R

    2017-02-01

    So far, the pathogenesis of Alzheimer's disease (AD) has not been clarified, nor has patient therapy been satisfactory. Although inheritance dominates the less frequent early-onset AD in young and middle-aged individuals, environmental and immunogenetic factors have been identified in the most frequently occurring late-onset AD of higher-aged individuals, comprising 90% of AD patients. Thorough investigations have detected a prevalence of certain microbes which are known to affect brain activities in the brains of AD patients. This microbial prevalence suggests failing immune responses by immune gene variants against specific microbes. In fact, some immune gene variants have been detected significantly more often in AD patients. Failing immune responses can be corrected by activating immune cells outside the body ("in vitro") for the subsequent therapeutical injections. Activated immune cells digest and present microbial peptides better and differentiate naïve/resting immune cells to powerful effector cells, which can be used for therapy. The patient's activated immune cells can pass the blood-brain barrier and overcome chronic infections in the brain. Furthermore, activated immune cells can secrete a series of neurotrophins for the restoration of neuronal circuits. Based on the encouraging results of immunotherapy in a patient with late-onset AD, we hypothesize that therapy with the patient's activated immune cells would safely benefit many AD patients. Copyright © 2016. Published by Elsevier Ltd.

  11. Circulating immune cell subpopulations in pestivirus persistently infected calves and non-infected calves varying in immune status [Abstract

    Science.gov (United States)

    The circulating immune cell subpopulations in cattle representing varying stages of immune status categorized as; colostrum deprived (CD), receiving colostrum (COL), colostrum plus vaccination (VAC) and persistently infected with a pestivirus (PI) were compared. The PI calves were infected with a H...

  12. Circulating immune cell subpopulations in pestivirus persistently infected calves and non-infected calves varying in immune status.

    Science.gov (United States)

    Circulating immune cell subpopulations in cattle representing varying stages of immune status categorized as; colostrum deprived (CD), receiving colostrum (COL), colostrum plus vaccination (VAC) and persistently infected with a pestivirus (PI) were compared. The PI calves were infected with a HoBi-...

  13. Vault nanocapsules as adjuvants favor cell-mediated over antibody-mediated immune responses following immunization of mice.

    Directory of Open Access Journals (Sweden)

    Upendra K Kar

    Full Text Available BACKGROUND: Modifications of adjuvants that induce cell-mediated over antibody-mediated immunity is desired for development of vaccines. Nanocapsules have been found to be viable adjuvants and are amenable to engineering for desired immune responses. We previously showed that natural nanocapsules called vaults can be genetically engineered to elicit Th1 immunity and protection from a mucosal bacterial infection. The purpose of our study was to characterize immunity produced in response to OVA within vault nanoparticles and compare it to another nanocarrier. METHODOLOGY AND PRINCIPAL FINDINGS: We characterized immunity resulting from immunization with the model antigen, ovalbumin (OVA encased in vault nanocapsules and liposomes. We measured OVA responsive CD8(+ and CD4(+ memory T cell responses, cytokine production and antibody titers in vitro and in vivo. We found that immunization with OVA contain in vaults induced a greater number of anti-OVA CD8(+ memory T cells and production of IFNγ plus CD4(+ memory T cells. Also, modification of the vault body could change the immune response compared to OVA encased in liposomes. CONCLUSIONS/SIGNIFICANCE: These experiments show that vault nanocapsules induced strong anti-OVA CD8(+ and CD4(+ T cell memory responses and modest antibody production, which markedly differed from the immune response induced by liposomes. We also found that the vault nanocapsule could be modified to change antibody isotypes in vivo. Thus it is possible to create a vault nanocapsule vaccine that can result in the unique combination of immunogen-responsive CD8(+ and CD4(+ T cell immunity coupled with an IgG1 response for future development of vault nanocapsule-based vaccines against antigens for human pathogens and cancer.

  14. Influenza vaccine induces intracellular immune memory of human NK cells.

    Directory of Open Access Journals (Sweden)

    Yaling Dou

    Full Text Available Influenza vaccines elicit antigen-specific antibodies and immune memory to protect humans from infection with drift variants. However, what supports or limits vaccine efficacy and duration is unclear. Here, we vaccinated healthy volunteers with annual vaccine formulations and investigated the dynamics of T cell, natural killer (NK cell and antibody responses upon restimulation with heterologous or homologous influenza virus strains. Influenza vaccines induced potential memory NK cells with increased antigen-specific recall IFN-γ responses during the first 6 months. In the absence of significant changes in other NK cell markers (CD45RO, NKp44, CXCR6, CD57, NKG2C, CCR7, CD62L and CD27, influenza vaccines induced memory NK cells with the distinct feature of intracellular NKp46 expression. Indeed, surface NKp46 was internalized, and the dynamic increase in NKp46(intracellular+CD56dim NK cells positively correlated with increased IFN-γ production to influenza virus restimulation after vaccination. In addition, anti-NKp46 antibodies blocked IFN-γ responses. These findings provide insights into a novel mechanism underlying vaccine-induced immunity and NK-related diseases, which may help to design persisting and universal vaccines in the future.

  15. Influenza vaccine induces intracellular immune memory of human NK cells.

    Science.gov (United States)

    Dou, Yaling; Fu, Binqing; Sun, Rui; Li, Wenting; Hu, Wanfu; Tian, Zhigang; Wei, Haiming

    2015-01-01

    Influenza vaccines elicit antigen-specific antibodies and immune memory to protect humans from infection with drift variants. However, what supports or limits vaccine efficacy and duration is unclear. Here, we vaccinated healthy volunteers with annual vaccine formulations and investigated the dynamics of T cell, natural killer (NK) cell and antibody responses upon restimulation with heterologous or homologous influenza virus strains. Influenza vaccines induced potential memory NK cells with increased antigen-specific recall IFN-γ responses during the first 6 months. In the absence of significant changes in other NK cell markers (CD45RO, NKp44, CXCR6, CD57, NKG2C, CCR7, CD62L and CD27), influenza vaccines induced memory NK cells with the distinct feature of intracellular NKp46 expression. Indeed, surface NKp46 was internalized, and the dynamic increase in NKp46(intracellular)+CD56dim NK cells positively correlated with increased IFN-γ production to influenza virus restimulation after vaccination. In addition, anti-NKp46 antibodies blocked IFN-γ responses. These findings provide insights into a novel mechanism underlying vaccine-induced immunity and NK-related diseases, which may help to design persisting and universal vaccines in the future.

  16. Dendritic Cell-Mediated Phagocytosis but Not Immune Activation Is Enhanced by Plasmin.

    OpenAIRE

    Borg, Rachael J.; Samson, Andre L.; Amanda E-L Au; Anja Scholzen; Martina Fuchsberger; Kong, Ying Y.; Roxann Freeman; Nicole A Mifsud; Magdalena Plebanski; Medcalf, Robert L.

    2015-01-01

    Removal of dead cells in the absence of concomitant immune stimulation is essential for tissue homeostasis. We recently identified an injury-induced protein misfolding event that orchestrates the plasmin-dependent proteolytic degradation of necrotic cells. As impaired clearance of dead cells by the innate immune system predisposes to autoimmunity, we determined whether plasmin could influence endocytosis and immune cell stimulation by dendritic cells - a critical cell that links the innate an...

  17. Stem cell factor gene transfer promotes cardiac repair after myocardial infarction via in situ recruitment and expansion of c-kit+ cells.

    Science.gov (United States)

    Yaniz-Galende, Elisa; Chen, Jiqiu; Chemaly, Elie; Liang, Lifan; Hulot, Jean-Sebastien; McCollum, LaTronya; Arias, Teresa; Fuster, Valentin; Zsebo, Krisztina M; Hajjar, Roger J

    2012-11-09

    There is growing evidence that the myocardium responds to injury by recruiting c-kit(+) cardiac progenitor cells to the damage tissue. Even though the ability of exogenously introducing c-kit(+) cells to injured myocardium has been established, the capability of recruiting these cells through modulation of local signaling pathways by gene transfer has not been tested. To determine whether stem cell factor gene transfer mediates cardiac regeneration in a rat myocardial infarction model, through survival and recruitment of c-kit(+) progenitors and cell-cycle activation in cardiomyocytes, and explore the mechanisms involved. Infarct size, cardiac function, cardiac progenitor cells recruitment, fibrosis, and cardiomyocyte cell-cycle activation were measured at different time points in controls (n=10) and upon stem cell factor gene transfer (n=13) after myocardial infarction. We found a regenerative response because of stem cell factor overexpression characterized by an enhancement in cardiac hemodynamic function: an improvement in survival; a reduction in fibrosis, infarct size and apoptosis; an increase in cardiac c-kit(+) progenitor cells recruitment to the injured area; an increase in cardiomyocyte cell-cycle activation; and Wnt/β-catenin pathway induction. Stem cell factor gene transfer induces c-kit(+) stem/progenitor cell expansion in situ and cardiomyocyte proliferation, which may represent a new therapeutic strategy to reverse adverse remodeling after myocardial infarction.

  18. Proteinase 3 on apoptotic cells disrupts immune silencing in autoimmune vasculitis

    Science.gov (United States)

    Millet, Arnaud; Martin, Katherine R.; Bonnefoy, Francis; Saas, Philippe; Mocek, Julie; Alkan, Manal; Terrier, Benjamin; Kerstein, Anja; Tamassia, Nicola; Satyanarayanan, Senthil Kumaran; Ariel, Amiram; Ribeil, Jean-Antoine; Guillevin, Loïc; Cassatella, Marco A.; Mueller, Antje; Thieblemont, Nathalie; Lamprecht, Peter; Mouthon, Luc; Perruche, Sylvain; Witko-Sarsat, Véronique

    2015-01-01

    Granulomatosis with polyangiitis (GPA) is a systemic necrotizing vasculitis that is associated with granulomatous inflammation and the presence of anti-neutrophil cytoplasmic antibodies (ANCAs) directed against proteinase 3 (PR3). We previously determined that PR3 on the surface of apoptotic neutrophils interferes with induction of antiinflammatory mechanisms following phagocytosis of these cells by macrophages. Here, we demonstrate that enzymatically active membrane-associated PR3 on apoptotic cells triggered secretion of inflammatory cytokines, including granulocyte CSF (G-CSF) and chemokines. This response required the IL-1R1/MyD88 signaling pathway and was dependent on the synthesis of NO, as macrophages from animals lacking these pathways did not exhibit a PR3-associated proinflammatory response. The PR3-induced microenvironment facilitated recruitment of inflammatory cells, such as macrophages, plasmacytoid DCs (pDCs), and neutrophils, which were observed in close proximity within granulomatous lesions in the lungs of GPA patients. In different murine models of apoptotic cell injection, the PR3-induced microenvironment instructed pDC-driven Th9/Th2 cell generation. Concomitant injection of anti-PR3 ANCAs with PR3-expressing apoptotic cells induced a Th17 response, revealing a GPA-specific mechanism of immune polarization. Accordingly, circulating CD4+ T cells from GPA patients had a skewed distribution of Th9/Th2/Th17. These results reveal that PR3 disrupts immune silencing associated with clearance of apoptotic neutrophils and provide insight into how PR3 and PR3-targeting ANCAs promote GPA pathophysiology. PMID:26436651

  19. The fungal quorum-sensing molecule farnesol activates innate immune cells but suppresses cellular adaptive immunity.

    Science.gov (United States)

    Leonhardt, Ines; Spielberg, Steffi; Weber, Michael; Albrecht-Eckardt, Daniela; Bläss, Markus; Claus, Ralf; Barz, Dagmar; Scherlach, Kirstin; Hertweck, Christian; Löffler, Jürgen; Hünniger, Kerstin; Kurzai, Oliver

    2015-03-17

    Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α] and macrophage inflammatory protein 1 alpha [MIP-1α]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance. Farnesol is a quorum-sensing molecule which controls morphological plasticity of the pathogenic yeast Candida albicans. As such, it is a major mediator of intraspecies communication. Here, we investigated the impact of farnesol on human innate immune cells known to be

  20. Emerging roles for platelets as immune and inflammatory cells.

    Science.gov (United States)

    Morrell, Craig N; Aggrey, Angela A; Chapman, Lesley M; Modjeski, Kristina L

    2014-05-01

    Despite their small size and anucleate status, platelets have diverse roles in vascular biology. Not only are platelets the cellular mediator of thrombosis, but platelets are also immune cells that initiate and accelerate many vascular inflammatory conditions. Platelets are linked to the pathogenesis of inflammatory diseases such as atherosclerosis, malaria infection, transplant rejection, and rheumatoid arthritis. In some contexts, platelet immune functions are protective, whereas in others platelets contribute to adverse inflammatory outcomes. In this review, we will discuss platelet and platelet-derived mediator interactions with the innate and acquired arms of the immune system and platelet-vessel wall interactions that drive inflammatory disease. There have been many recent publications indicating both important protective and adverse roles for platelets in infectious disease. Because of this new accumulating data, and the fact that infectious disease continues to be a leading cause of death globally, we will also focus on new and emerging concepts related to platelet immune and inflammatory functions in the context of infectious disease.

  1. Natural killer (NK): dendritic cell (DC) cross talk induced by therapeutic monoclonal antibody triggers tumor antigen-specific T cell immunity.

    Science.gov (United States)

    Lee, Steve C; Srivastava, Raghvendra M; López-Albaitero, Andrés; Ferrone, Soldano; Ferris, Robert L

    2011-08-01

    Tumor antigen (TA)-targeted monoclonal antibodies (mAb), trastuzumab, cetuximab, panitumumab, and rituximab, have been among the most successful new therapies in the present generation. Clinical activity is observed as a single agent, or in combination with radiotherapy or chemotherapy, against metastatic colorectal cancer, head and neck cancer, breast cancer, and follicular lymphoma. However, the activity is seen only in a minority of patients. Thus, an intense need exists to define the mechanism of action of these immunoactive mAb. Here, we discuss some of the likely immunological events that occur in treated patients: antibody-dependent cellular cytotoxicity (ADCC), cross talk among immune cells including NK cells and dendritic cells (DCs), and generation of TA-specific T lymphocyte responses. We present evidence supporting the induction of "NK:DC cross talk," leading to priming of TA-specific cellular immunity. These observations show that mAb-mediated NK cell activation can be greatly enhanced by the action of stimulatory cytokines and surface molecules on maturing DC and that NK:DC interaction facilitates the recruitment of both NK cells and DC to the tumor site(s). The cooperative, reciprocal stimulatory activity of both NK cells and DC can modulate both the innate immune response in the local tumor microenvironment and the adaptive immune response in secondary lymphoid organs. These events likely contribute to clinical activity, as well as provide a potential biomarker of response to mAb therapy.

  2. Monocyte-derived dendritic cells exposed to Der p 1 allergen enhance the recruitment of Th2 cells: major involvement of the chemokines TARC/CCL17 and MDC/CCL22.

    Science.gov (United States)

    Hammad, Hamida; Smits, Hermelijn H; Ratajczak, Céline; Nithiananthan, Asokananthan; Wierenga, Eddy A; Stewart, Geoffrey A; Jacquet, Alain; Tonnel, Andre-Bernard; Pestel, Joël

    2003-01-01

    Dendritic cells (DC) are potent antigen - presenting cells that can orientate the immune response towards a Th1 or a Th2 type. DC produce chemokines that are involved in the recruitment of either Th1 cells, such as IP10 (CXCL10), Th2 cells such as TARC (CCL17) and MDC (CCL22), or non-polarized T cells such as RANTES (CCL5) and MIP-lalpha (CCL3). We investigated whether monocyte-derived DC (MD-DC) generated from healthy donors or from patients sensitive to Dermatophagoides pteronyssinus (Dpt) and exposed to the cysteine-protease Der p 1(allergen of Dpt), could upregulate the expression of chemokines involved in type 1 or type 2 T cell recruitment. MD-DC were pulsed with either Der p 1 or with LPS as the control and the chemokines produced were evaluated using ELISA and chemotaxis assays. Der p 1-pulsed DC from allergic patients showed increased TARC (CCL17) and MDC (CCL22) production without modifying IP-10 (CXCL10) release. Der p 1-pulsed DC from healthy donors showed only increased IP-10 (CXCL10) secretion. RANTES (CCL5) and MIP-lalpha (CCL3) production were similarly increased when DC were from healthy or allergic donors. The selective Th2 clone recruitment activity of supernatants from Der p 1-pulsed DC of allergic patients was inhibited by anti-TARC (CCL17) and anti-MDC (CCL22) neutralizing Abs. By using anti-IP10 (CXCL10) blocking Abs, supernatants of Der p 1-pulsed DC from healthy donors were shown to be involved in the recruitment of Th1 cells. These results suggest that in allergic patients exposed to house dust mites, DC may favour the exacerbation of the Th2 response via the increase in type 2 chemokine production. Copyright John Libbey Eurotext 2003.

  3. Motor neurons and oligodendrocytes arise from distinct cell lineages by progenitor recruitment.

    Science.gov (United States)

    Ravanelli, Andrew M; Appel, Bruce

    2015-12-01

    During spinal cord development, ventral neural progenitor cells that express the transcription factors Olig1 and Olig2, called pMN progenitors, produce motor neurons and then oligodendrocytes. Whether motor neurons and oligodendrocytes arise from common or distinct progenitors in vivo is not known. Using zebrafish, we found that motor neurons and oligodendrocytes are produced sequentially by distinct progenitors that have distinct origins. When olig2(+) cells were tracked during the peak period of motor neuron formation, most differentiated as motor neurons without further cell division. Using time-lapse imaging, we found that, as motor neurons differentiated, more dorsally positioned neuroepithelial progenitors descended to the pMN domain and initiated olig2 expression. Inhibition of Hedgehog signaling during motor neuron differentiation blocked the ventral movement of progenitors, the progressive initiation of olig2 expression, and oligodendrocyte formation. We therefore propose that the motor neuron-to-oligodendrocyte switch results from Hedgehog-mediated recruitment of glial-fated progenitors to the pMN domain subsequent to neurogenesis.

  4. Fasciola hepatica Immune Regulates CD11c+ Cells by Interacting with the Macrophage Gal/GalNAc Lectin

    Science.gov (United States)

    Rodríguez, Ernesto; Carasi, Paula; Frigerio, Sofía; da Costa, Valeria; van Vliet, Sandra; Noya, Verónica; Brossard, Natalie; van Kooyk, Yvette; García-Vallejo, Juan J.; Freire, Teresa

    2017-01-01

    Fasciolosis, caused by Fasciola hepatica and Fasciola gigantica, is a trematode zoonosis of interest in public health and livestock production. Like other helminths, F. hepatica modulates the host immune response by inducing potent polarized Th2 and regulatory T cell immune responses and by downregulating the production of Th1 cytokines. In this work, we show that F. hepatica glycans increase Th2 immune responses by immunomodulating TLR-induced maturation and function of dendritic cells (DCs). This process was mediated by the macrophage Gal/GalNAc lectin (MGL) expressed on DCs, which recognizes the Tn antigen (GalNAc-Ser/Thr) on parasite components. More interestingly, we identified MGL-expressing CD11c+ cells in infected animals and showed that these cells are recruited both to the peritoneum and the liver upon F. hepatica infection. These cells express the regulatory cytokines IL-10, TNFα and TGFβ and a variety of regulatory markers. Furthermore, MGL+ CD11c+ cells expand parasite-specific Th2/regulatory cells and suppress Th1 polarization. The results presented here suggest a potential role of MGL in the immunomodulation of DCs induced by F. hepatica and contribute to a better understanding of the molecular and immunoregulatory mechanisms induced by this parasite. PMID:28360908

  5. CD45/CD8 myeloid histioid antigen and plasma cell antibody immune response in a case of malignant melanoma

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu-Velez

    2012-01-01

    Full Text Available The immune response in metastatic melanoma is not well established and therefore is of particular interest to test for recruitment of immune cells to the tumor. A 46-year-old Caucasian female was evaluated for an asymptomatic right forearm mass. The lesion had been present for at least 4 years and had become painful 4 months ago. Biopsies for hematoxylin and eosin (H and E staining, as well as immunohistochemical analysis were performed on the primary tumor and on sentinel lymph nodes. The H and E staining was consistent with metastatic melanoma. Positive staining was noted on the tumor cells with S-100, Mart-1/Melan A/CD63, PNL2, HMB45, and tyrosinase. Peritumoral and intratumoral inflammatory cells stained positive for CD8, CD45, PCNA, myeloid histoid antigen, antihuman plasma cell antibody, and focal BRCA1. The staining patterns of CD8/CD45, myeloid histoid antigen and plasma cell antibody on inflammatory cells around the melanoma cells suggest an unusual type of immune response.

  6. Fasciola hepatica Immune Regulates CD11c(+) Cells by Interacting with the Macrophage Gal/GalNAc Lectin.

    Science.gov (United States)

    Rodríguez, Ernesto; Carasi, Paula; Frigerio, Sofía; da Costa, Valeria; van Vliet, Sandra; Noya, Verónica; Brossard, Natalie; van Kooyk, Yvette; García-Vallejo, Juan J; Freire, Teresa

    2017-01-01

    Fasciolosis, caused by Fasciola hepatica and Fasciola gigantica, is a trematode zoonosis of interest in public health and livestock production. Like other helminths, F. hepatica modulates the host immune response by inducing potent polarized Th2 and regulatory T cell immune responses and by downregulating the production of Th1 cytokines. In this work, we show that F. hepatica glycans increase Th2 immune responses by immunomodulating TLR-induced maturation and function of dendritic cells (DCs). This process was mediated by the macrophage Gal/GalNAc lectin (MGL) expressed on DCs, which recognizes the Tn antigen (GalNAc-Ser/Thr) on parasite components. More interestingly, we identified MGL-expressing CD11c(+) cells in infected animals and showed that these cells are recruited both to the peritoneum and the liver upon F. hepatica infection. These cells express the regulatory cytokines IL-10, TNFα and TGFβ and a variety of regulatory markers. Furthermore, MGL(+) CD11c(+) cells expand parasite-specific Th2/regulatory cells and suppress Th1 polarization. The results presented here suggest a potential role of MGL in the immunomodulation of DCs induced by F. hepatica and contribute to a better understanding of the molecular and immunoregulatory mechanisms induced by this parasite.

  7. The interplay of sequence conservation and T cell immune recognition

    DEFF Research Database (Denmark)

    Bresciani, Anne Gøther; Sette, Alessandro; Greenbaum, Jason

    2014-01-01

    Predicting which peptides can elicit a T cell response (i.e. are immunogenic) is of great importance for many immunological studies. While it is clear that MHC binding is a necessary requirement for peptide immunogenicity, other variables exist that are incompletely understood. In this study we...... the Immune Epitope Database with their conservation in the human microbiome. Indeed, we did see a lower immunogenicity for conserved peptides conserved. While many aspects how this conservation comparison is done require further optimization, this is a first step towards a better understanding T cell...

  8. Immune and Inflammatory Cell Composition of Human Lung Cancer Stroma: e0139073

    National Research Council Canada - National Science Library

    G-Andre Banat; Aleksandra Tretyn; Soni Savai Pullamsetti; Jochen Wilhelm; Andreas Weigert; Catherine Olesch; Katharina Ebel; Thorsten Stiewe; Friedrich Grimminger; Werner Seeger; Ludger Fink; Rajkumar Savai

    2015-01-01

    .... We comprehensively assessed the number of stromal cells, especially immune/inflammatory cells, in lung cancer and evaluated their infiltration in cancers of different stages, types and metastatic...

  9. Activated T cells recruit exosomes secreted by dendritic cells via LFA-1.

    NARCIS (Netherlands)

    Nolte-'t Hoen, E.N.; Buschow, S.I.; Anderton, S.M.; Stoorvogel, W.; Wauben, M.H.M.

    2009-01-01

    Dendritic cells (DCs) are known to secrete exosomes that transfer membrane proteins, like major histocompatibility complex class II, to other DCs. Intercellular transfer of membrane proteins is also observed during cognate interactions between DCs and CD4(+) T cells. The acquired proteins are functi

  10. Neural progenitor cells from human induced pluripotent stem cells generated less autogenous immune response.

    Science.gov (United States)

    Huang, Ke; Liu, PengFei; Li, Xiang; Chen, ShuBin; Wang, LiHui; Qin, Li; Su, ZhengHui; Huang, WenHao; Liu, Juli; Jia, Bei; Liu, Jie; Cai, JingLei; Pei, DuanQing; Pan, GuangJin

    2014-02-01

    The breakthrough development of induced pluripotent stem cells (iPSCs) raises the prospect of patient-specific treatment for many diseases through the replacement of affected cells. However, whether iPSC-derived functional cell lineages generate a deleterious immune response upon auto-transplantation remains unclear. In this study, we differentiated five human iPSC lines from skin fibroblasts and urine cells into neural progenitor cells (NPCs) and analyzed their immunogenicity. Through co-culture with autogenous peripheral blood mononuclear cells (PBMCs), we showed that both somatic cells and iPSC-derived NPCs do not stimulate significant autogenous PBMC proliferation. However, a significant immune reaction was detected when these cells were co-cultured with allogenous PBMCs. Furthermore, no significant expression of perforin or granzyme B was detected following stimulation of autogenous immune effector cells (CD3(+)CD8(-) T cells, CD3(+)CD8(+) T cells or CD3(-)CD56(+) NK cells) by NPCs in both PBMC and T cell co-culture systems. These results suggest that human iPSC-derived NPCs may not initiate an immune response in autogenous transplants, and thus set a base for further preclinical evaluation of human iPSCs.

  11. Tumor Irradiation Increases the Recruitment of Circulating Mesenchymal Stem Cells into the Tumor Microenvironment

    Science.gov (United States)

    Klopp, Ann H.; Spaeth, Erika L.; Dembinski, Jennifer L.; Woodward, Wendy A.; Munshi, Anupama; Meyn, Raymond E.; Cox, James D.; Andreeff, Michael; Marini, Frank C.

    2011-01-01

    Mesenchymal stem cells (MSC) migrate to and proliferate within sites of inflammation and tumors as part of the tissue remodeling process. Radiation increases the expression of inflammatory mediators that could enhance the recruitment of MSC into the tumor microenvironment. To investigate this, bilateral murine 4T1 breast carcinomas (expressing renilla luciferase) were irradiated unilaterally (1 or 2 Gy). Twenty-four hours later, 2 × 105 MSC-expressing firefly luciferase were injected i.v. Mice were then monitored with bioluminescent imaging for expression of both renilla (tumor) and firefly (MSC) luciferase. Forty-eight hours postirradiation, levels of MSC engraftment were 34% higher in tumors receiving 2 Gy (P = 0.004) than in the contralateral unirradiated limb. Immunohistochemical staining of tumor sections from mice treated unilaterally with 2 Gy revealed higher levels of MSC in the parenchyma of radiated tumors, whereas a higher proportion of MSC remained vasculature-associated in unirradiated tumors. To discern the potential mediators involved in MSC attraction, in vitro migration assays showed a 50% to 80% increase in MSC migration towards conditioned media from 1 to 5 Gy-irradiated 4T1 cells compared with unirradiated 4T1 cells. Irradiated 4T1 cells had increased expression of the cytokines, transforming growth factor-β1, vascular endothelial growth factor, and platelet-derived growth factor-BB, and this up-regulation was confirmed by immunohistochemistry in tumors irradiated in vivo. Interestingly, the chemokine receptor CCR2 was found to be up-regulated in MSC exposed to irradiated tumor cells and inhibition of CCR2 led to a marked decrease of MSC migration in vitro. In conclusion, clinically relevant low doses of irradiation increase the tropism for and engraftment of MSC in the tumor microenvironment. PMID:18089798

  12. Colonic inflammation in mice is improved by cigarette smoke through iNKT cells recruitment.

    Directory of Open Access Journals (Sweden)

    Muriel Montbarbon

    Full Text Available Cigarette smoke (CS protects against intestinal inflammation during ulcerative colitis. Immunoregulatory mechanisms sustaining this effect remain unknown. The aim of this study was to assess the effects of CS on experimental colitis and to characterize the intestinal inflammatory response at the cellular and molecular levels. Using the InExpose® System, a smoking device accurately reproducing human smoking habit, we pre-exposed C57BL/6 mice for 2 weeks to CS, and then we induced colitis by administration of dextran sodium sulfate (DSS. This system allowed us to demonstrate that CS exposure improved colonic inflammation (significant decrease in clinical score, body weight loss and weight/length colonic ratio. This improvement was associated with a significant decrease in colonic proinflammatory Th1/Th17 cytokine expression, as compared to unexposed mice (TNF (p=0.0169, IFNγ (p<0.0001, and IL-17 (p=0.0008. Smoke exposure also induced an increased expression of IL-10 mRNA (p=0.0035 and a marked recruitment of iNKT (invariant Natural Killer T; CD45+ TCRβ+ CD1d tetramer+ cells in the colon of DSS-untreated mice. Demonstration of the role of iNKT cells in CS-dependent colitis improvement was performed using two different strains of NKT cells deficient mice. Indeed, in Jα18KO and CD1dKO animals, CS exposure failed to induce significant regulation of DSS-induced colitis both at the clinical and molecular levels. Thus, our study demonstrates that iNKT cells are pivotal actors in the CS-dependent protection of the colon. These results highlight the role of intestinal iNKT lymphocytes and their responsiveness to environmental stimuli. Targeting iNKT cells would represent a new therapeutic way for inflammatory bowel diseases.

  13. The Current Immune Function of Hepatic Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Willy Hsu; Shang-An Shu; Eric Gershwin; Zhe-Xiong Lian

    2007-01-01

    While only a small percentage of the liver as dendritic cells, they play a major role in the regulation of liver immunity. Four major types of dendritic cell subsets include myeloid CD8α-B220-, lymphoid CD8α+B220-,plasmacytoid CD8α-B220+, and natural killer dendritic cell with CD8α-B220-NK1.1+ phenotype. Although these subsets have slightly different characteristics, they are all poor na(i)ve T cell stimulators. In exchange for their reduced capacity for allostimulation, hepatic DCs are equipped with an enhanced ability to secrete cytokines in response to TLR stimulation. In addition, they have increased level of phagocytosis. Both of these traits suggest hepatic DC as part of the innate immune system. With such a high rate of exposure to the dietary and commensal antigens, it is important for the hepatic DCs to have an enhanced innate response while maintaining a tolerogenic state to avoid chronic inflammation. Only upon secondary infectivity does the hepatic DC activate memory T cells for rapid eradication of recurring pathogen. On the other hand, overly tolerogenic characteristics of hepatic DC may be responsible for the increase prevalence of autoimmunity or liver malignancies.

  14. Effects of PVA coated nanoparticles on human immune cells.

    Science.gov (United States)

    Strehl, Cindy; Gaber, Timo; Maurizi, Lionel; Hahne, Martin; Rauch, Roman; Hoff, Paula; Häupl, Thomas; Hofmann-Amtenbrink, Margarethe; Poole, A Robin; Hofmann, Heinrich; Buttgereit, Frank

    2015-01-01

    Nanotechnology provides new opportunities in human medicine, mainly for diagnostic and therapeutic purposes. The autoimmune disease rheumatoid arthritis (RA) is often diagnosed after irreversible joint structural damage has occurred. There is an urgent need for a very early diagnosis of RA, which can be achieved by more sensitive imaging methods. Superparamagnetic iron oxide nanoparticles (SPION) are already used in medicine and therefore represent a promising tool for early diagnosis of RA. The focus of our work was to investigate any potentially negative effects resulting from the interactions of newly developed amino-functionalized amino-polyvinyl alcohol coated (a-PVA) SPION (a-PVA-SPION), that are used for imaging, with human immune cells. We analyzed the influence of a-PVA-SPION with regard to cell survival and cell activation in human whole blood in general, and in human monocytes and macrophages representative of professional phagocytes, using flow cytometry, multiplex suspension array, and transmission electron microscopy. We found no effect of a-PVA-SPION on the viability of human immune cells, but cytokine secretion was affected. We further demonstrated that the percentage of viable macrophages increased on exposure to a-PVA-SPION. This effect was even stronger when a-PVA-SPION were added very early in the differentiation process. Additionally, transmission electron microscopy analysis revealed that both monocytes and macrophages are able to endocytose a-PVA-SPION. Our findings demonstrate an interaction between human immune cells and a-PVA-SPION which needs to be taken into account when considering the use of a-PVA-SPION in human medicine.

  15. Corneal Fibroblasts as Sentinel Cells and Local Immune Modulators in Infectious Keratitis

    Directory of Open Access Journals (Sweden)

    Ken Fukuda

    2017-08-01

    Full Text Available The cornea serves as a barrier to protect the eye against external insults including microbial pathogens and antigens. Bacterial infection of the cornea often results in corneal melting and scarring that can lead to severe visual impairment. Not only live bacteria but also their components such as lipopolysaccharide (LPS of Gram-negative bacteria contribute to the development of inflammation and subsequent corneal damage in infectious keratitis. We describe the important role played by corneal stromal fibroblasts (activated keratocytes as sentinel cells, immune modulators, and effector cells in infectious keratitis. Corneal fibroblasts sense bacterial infection through Toll-like receptor (TLR–mediated detection of a complex of LPS with soluble cluster of differentiation 14 (CD14 and LPS binding protein present in tear fluid. The cells then initiate innate immune responses including the expression of chemokines and adhesion molecules that promote the recruitment of inflammatory cells necessary for elimination of the infecting bacteria. Infiltrated neutrophils are activated by corneal stromal collagen and release mediators that stimulate the production of pro–matrix metalloproteinases by corneal fibroblasts. Elastase produced by Pseudomonas aeruginosa (P. aeruginosa activates these released metalloproteinases, resulting in the degradation of stromal collagen. The modulation of corneal fibroblast activation and of the interaction of these cells with inflammatory cells and bacteria is thus important to minimize corneal scarring during treatment of infectious keratitis. Pharmacological agents that are able to restrain such activities of corneal fibroblasts without allowing bacterial growth represent a potential novel treatment option for prevention of excessive scarring and tissue destruction in the cornea.

  16. The evolving paradigm of cell-nonautonomous UPR-based regulation of immunity by cancer cells.

    Science.gov (United States)

    Zanetti, M; Rodvold, J J; Mahadevan, N R

    2016-01-21

    The endoplasmic reticulum (ER) stress response/unfolded protein response (UPR) has been thought to influence tumorigenesis mainly through cell-intrinsic, pro-survival effects. In recent years, however, new evidence has emerged showing that the UPR is also the source of cell-extrinsic effects, particularly directed at those immune cells within the tumor microenvironment. Here we will review and discuss this new body of information with focus on the role of cell-extrinsic effects on innate and adaptive immunity, suggesting that the transmission of ER stress from cancer cells to myeloid cells in particular is an expedient used by cancer cells to control the immune microenvironment, which acquires pro-inflammatory as well as immune-suppressive characteristics. These new findings can now be seen in the broader context of similar phenomena described in Caenorhabditis elegans, and an analogy with quorum sensing and 'community effects' in prokaryotes and eukaryotes can be drawn, arguing that a cell-nonautonomous UPR-based regulation of heterologous cells may be phylogenetically conserved. Finally, we will discuss the role of aneuploidy as an inducer of proteotoxic stress and potential initiator of cell-nonautonomous UPR-based regulation. In presenting these new views, we wish to bring attention to the cell-extrinsic regulation of tumor growth, including tumor UPR-based cell-nonautonomous signaling as a mechanism of maintaining tumor heterogeneity and resistance to therapy, and suggest therapeutically targeting such mechanisms within the tumor microenvironment.

  17. Vaccine with beta-defensin 2-transduced leukemic cells activates innate and adaptive immunity to elicit potent antileukemia responses.

    Science.gov (United States)

    Ma, Xiao-Tong; Xu, Bin; An, Li-Li; Dong, Cheng-Ya; Lin, Yong-Min; Shi, Yang; Wu, Ke-Fu

    2006-01-15

    Murine beta-defensin 2 (MBD2) is a small antimicrobial peptide of the innate immune system. Recent study showed that MBD2 could not only recruit immature dendritic cells but also activate them by Toll-like receptor 4 and thus may provide a critical link between the innate immune system and the adaptive immune response. In this report, we examined the antileukemia activity of MBD2 in a murine model of acute lymphoid leukemia (ALL) L1210. L1210 cells were engineered to secrete biologically functional MBD2. MBD2-modified L1210 (L1210-MBD2) showed significantly reduced leukemogenecity, resulting in a 80% rate of complete leukemia rejection. Inoculation of mice with L1210-MBD2 induced enhanced CTL and natural killer (NK) activity and augmented interleukin-12 and IFN-gamma production. All the recovered mice from the inoculation showed a protective immunity to the following challenge with parental L1210 cells and generate leukemia-specific memory CTL. Vaccines with irradiated L1210-MBD2 cells could cure 50% leukemia-bearing mice. Depletion of CD8+ T cells but not CD4+ T cells completely abrogated the antileukemia activity of MBD2. Interestingly, NK cells were also required for the MBD2-mediated antileukemia response, although ALL generally display a high degree of resistance to NK-mediated lysis. Our results suggest that MBD2 can activate both innate and adaptive immunity to generate potent antileukemia response, and MBD2 immunotherapy warrants further evaluation as a potential treatment for ALL.

  18. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils

    DEFF Research Database (Denmark)

    Galli, Stephen J; Borregaard, Niels; Wynn, Thomas A

    2011-01-01

    Hematopoietic cells, including lymphoid and myeloid cells, can develop into phenotypically distinct 'subpopulations' with different functions. However, evidence indicates that some of these subpopulations can manifest substantial plasticity (that is, undergo changes in their phenotype and functio...... a common mechanism for modulating innate or adaptive immunity.......). Here we focus on the occurrence of phenotypically distinct subpopulations in three lineages of myeloid cells with important roles in innate and acquired immunity: macrophages, mast cells and neutrophils. Cytokine signals, epigenetic modifications and other microenvironmental factors can substantially...... and, in some cases, rapidly and reversibly alter the phenotype of these cells and influence their function. This suggests that regulation of the phenotype and function of differentiated hematopoietic cells by microenvironmental factors, including those generated during immune responses, represents...

  19. Autoreactive T cells in the immune pathogenesis of pemphigus vulgaris.

    Science.gov (United States)

    Amber, Kyle T; Staropoli, Patrick; Shiman, Michael I; Elgart, George W; Hertl, Michael

    2013-11-01

    Pemphigus vulgaris is a life-threatening autoimmune blistering disease caused by anti-desmoglein IgG autoantibodies that finally lead to acantholysis presenting clinically as progressive blistering. Whilst the production of pathogenic antibodies is key to the development of pemphigus vulgaris, many immunological steps are required prior to autoantibody induction. We review advances in the understanding of these immunologic processes with a focus on human leucocyte antigen polymorphisms and antigen recognition, epitope spreading, central and peripheral tolerance, T helper differentiation, induction of pro- and anti-inflammatory cytokines and T-cell regulation of B cells. Targeting autoaggressive T cells as regulators and stimulators of B-cell antibody production should allow for more specific therapeutic immune interventions, avoiding the global immunosuppression seen with many commonly used immunosuppressants in pemphigus vulgaris.

  20. Metabolic and Epigenetic Coordination of T Cell and Macrophage Immunity.

    Science.gov (United States)

    Phan, Anthony T; Goldrath, Ananda W; Glass, Christopher K

    2017-05-16

    Recognition of pathogens by innate and adaptive immune cells instructs rapid alterations of cellular processes to promote effective resolution of infection. To accommodate increased bioenergetic and biosynthetic demands, metabolic pathways are harnessed to maximize proliferation and effector molecule production. In parallel, activation initiates context-specific gene-expression programs that drive effector functions and cell fates that correlate with changes in epigenetic landscapes. Many chromatin- and DNA-modifying enzymes make use of substrates and cofactors that are intermediates of metabolic pathways, providing potential cross talk between metabolism and epigenetic regulation of gene expression. In this review, we discuss recent studies of T cells and macrophages supporting a role for metabolic activity in integrating environmental signals with activation-induced gene-expression programs through modulation of the epigenome and speculate as to how this may influence context-specific macrophage and T cell responses to infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Dendritic cell based genetic immunization stimulates potent tumor protection dependent on CD8 CTL cells in the absence of autoimmunity.

    Science.gov (United States)

    Zhang, Sheng; Huang, Weiyi

    2008-09-01

    Although antibodies (Abs) produced by B cells can treat cancer in certain models, T cells have been accountable for the major effector to control cancer. Immune recognition toward tyrosinase-related protein-1 (TRP-1), a melanoma associated antigen up-regulated on the surface of B16F10 melanomas, generally leads to tumor protection mediated by Abs. In this study, immunization with dendritic cells ex vivo transduced with adenovirus encoding TRP-1 stimulates immune activation and potent tumor protection mediated by CD8 T cells in the absence of autoimmune consequence. Transfer of CD8 T cells from immunized mice also leads to tumor protection. The immune activation and CD8 T cell mediated tumor protection rely on the CD4 T cell help. Thus DC based genetic immunization targeting TRP-1, an antigen usually causes Ab predominant immune recognition, is capable of stimulating potent tumor protection dependent on CD8 T cells in the absence of autoimmunity.

  2. Cell mediated immune response in human antirabies revaccination

    Directory of Open Access Journals (Sweden)

    Débora Regina Veiga

    1987-04-01

    Full Text Available The occurrence of secondary cell mediated immune response (CMI in human antirabies immunization was studied. The Puenzalida & Palácios vaccine was used because it is routinely used in Brazil. CMI was evaluated by lymphoblastic transformation indices obtained in whole blood culture in the presence of rabies and control (nervous tissue antigens. Eleven volunteers submitted to revaccination constituted the group under study, while three other volunteers submitted primo vaccination were utilized as control group. A clear secondary CMI to rabies antigen was detected in all the revaccinated volunteers who showed earlier and more intense response than the control group. Response to the control antigen, however, present in all the components of the first group was not detectable in two out of the three primovaccinated and very low in the third one.

  3. Innate immunity in the pathogenesis of psoriasis.

    LENUS (Irish Health Repository)

    Sweeney, Cheryl M

    2011-12-01

    Psoriasis is a common, immune-mediated inflammatory skin disorder. T helper(h)1 and Th17 lymphocytes contribute to the pathogenesis of psoriasis through the release of inflammatory cytokines that promote further recruitment of immune cells, keratinocyte proliferation and sustained inflammation. The innate immune system is the first line of defence against infection and plays a crucial role in the initiation of the adaptive immune response. The presence of innate immune cells and their products in psoriatic skin plaques suggests a role for innate immunity in this disease. In addition, the innate immune system can direct the development of pathogenic Th cells in psoriasis. In this article, we will summarise the role of the innate immune system in psoriasis with particular emphasis on the role of cytokines, signalling pathways and cells of the innate immune system.

  4. Bystander T cells in human immune responses to dengue antigens

    Directory of Open Access Journals (Sweden)

    Suwannasaen Duangchan

    2010-09-01

    Full Text Available Abstract Background Previous studies of T cell activation in dengue infection have focused on restriction of specific T cell receptors (TCRs and classical MHC molecules. However, bystander T cell activation, which is TCR independent, occurs via cytokines in other viral infections, both in vitro and in vivo, and enables T cells to bypass certain control checkpoints. Moreover, clinical and pathological evidence has pointed to cytokines as the mediators of dengue disease severity. Therefore, we investigated bystander T cell induction by dengue viral antigen. Results Whole blood samples from 55 Thai schoolchildren aged 13-14 years were assayed for in vitro interferon-gamma (IFN-γ induction in response to inactivated dengue serotype 2 antigen (Den2. The contribution of TCR-dependent and independent pathways was tested by treatment with cyclosporin A (CsA, which inhibits TCR-dependent activation of T cells. ELISA results revealed that approximately 72% of IFN-γ production occurred via the TCR-dependent pathway. The major IFN-γ sources were natural killer (NK (mean ± SE = 55.2 ± 3.3, CD4+T (24.5 ± 3.3 and CD8+T cells (17.9 ± 1.5, respectively, as demonstrated by four-color flow cytometry. Interestingly, in addition to these cells, we found CsA-resistant IFN-γ producing T cells (CD4+T = 26.9 ± 3.6% and CD8+T = 20.3 ± 2.1% implying the existence of activated bystander T cells in response to dengue antigen in vitro. These bystander CD4+ and CD8+T cells had similar kinetics to NK cells, appeared after 12 h and were inhibited by anti-IL-12 neutralization indicating cytokine involvement. Conclusions This study described immune cell profiles and highlighted bystander T cell activation in response to dengue viral antigens of healthy people in an endemic area. Further studies on bystander T cell activation in dengue viral infection may reveal the immune mechanisms that protect or enhance pathogenesis of secondary dengue infection.

  5. Mesenchymal stromal cells and immunomodulation: A gathering of regulatory immune cells.

    Science.gov (United States)

    Najar, Mehdi; Raicevic, Gordana; Fayyad-Kazan, Hussein; Bron, Dominique; Toungouz, Michel; Lagneaux, Laurence

    2016-02-01

    Because of their well-recognized immunomodulatory properties, mesenchymal stromal cells (MSCs) represent an attractive cell population for therapeutic purposes. In particular, there is growing interest in the use of MSCs as cellular immunotherapeutics for tolerance induction in allogeneic transplantations and the treatment of autoimmune diseases. However, multiple mechanisms have been identified to mediate the immunomodulatory effects of MSCs, sometimes with several ambiguities and inconsistencies. Although published studies have mainly reported the role of soluble factors, we believe that a sizeable cellular component plays a critical role in MSC immunomodulation. We refer to these cells as regulatory immune cells, which are generated from both the innate and adaptive responses after co-culture with MSCs. In this review, we discuss the nature and role of these immune regulatory cells as well as the role of different mediators, and, in particular, regulatory immune cell induction by MSCs through interleukin-10. Once induced, immune regulatory cells accumulate and converge their regulatory pathways to create a tolerogenic environment conducive for immunomodulation. Thus, a better understanding of these regulatory immune cells, in terms of how they can be optimally manipulated and induced, would be suitable for improving MSC-based immunomodulatory therapeutic strategies.

  6. Molecular mechanisms involved in secretory vesicle recruitment to the plasma membrane in beta-cells.

    Science.gov (United States)

    Varadi, Aniko; Ainscow, E K; Allan, V J; Rutter, G A

    2002-04-01

    Glucose stimulates the release of insulin in part by activating the recruitment of secretory vesicles to the cell surface. While this movement is known to be microtubule-dependent, the molecular motors involved are undefined. Active kinesin was found to be essential for vesicle translocation in live beta-cells, since microinjection of cDNA encoding dominant-negative KHC(mut) (motor domain of kinesin heavy chain containing a Thr(93)-->Asn point mutation) blocked vesicular movements. Moreover, expression of KHC(mut) strongly inhibited the sustained, but not acute, stimulation of secretion by glucose. Thus, vesicles released during the first phase of insulin secretion exist largely within a translocation-independent pool. Kinesin-driven anterograde movement of vesicles is then necessary for the sustained (second phase) of insulin release. Kinesin may, therefore, represent a novel target for increases in intracellular ATP concentrations in response to elevated extracellular glucose and may be involved in the ATP-sensitive K+channel-independent stimulation of secretion by the sugar.

  7. Levels of immune cells in transcendental meditation practitioners

    Science.gov (United States)

    Infante, Jose R; Peran, Fernando; Rayo, Juan I; Serrano, Justo; Domínguez, Maria L; Garcia, Lucia; Duran, Carmen; Roldan, Ana

    2014-01-01

    Context: Relationships between mind and body have gradually become accepted. Yogic practices cause modulation of the immune system. Transcendental meditation (TM) is a specific form of mantra meditation. We reported previously different plasma levels of catecholamines and pituitary hormones in TM practitioners comparing with a control group, and patterns of the daytime secretion of these hormones different from those normally described. Aims: The aim of the following study is to evaluate the immune system in these meditation practitioners, by determining leukocytes and lymphocytes subsets. Methods: TM group consisted of 19 subjects who regularly practice either TM or the more advanced Sidhi-TM technique. A control group consisted of 16 healthy subjects who had not previously used any relaxation technique. Total leukocytes, granulocytes, lymphocytes and monocytes were counted by an automated quantitative hematology analyzer, whereas lymphocytes subsets were determined by flow cytometry. Samples were taken from each subject at 0900 h after an overnight fast. Results: The results indicated that the TM group had higher values than the control group in CD3+CD4−CD8+ lymphocytes (P < 0.05), B lymphocytes (P < 0.01) and natural killer cells (P < 0.01), whereas CD3+CD4+CD8− lymphocytes showed low levels in meditation practitioners (P < 0.001). No significant differences were observed in total leukocytes, granulocytes, monocytes, total lymphocytes or CD3+ lymphocytes comparing both groups. Conclusions: The technique of meditation studied seems to have a significant effect on immune cells, manifesting in the different circulating levels of lymphocyte subsets analyzed. The significant effect of TM on the neuroendocrine axis and its relationship with the immune system may partly explain our results. PMID:25035626

  8. Primary antitumor immune response mediated by CD4+ T cells.

    Science.gov (United States)

    Corthay, Alexandre; Skovseth, Dag K; Lundin, Katrin U; Røsjø, Egil; Omholt, Hilde; Hofgaard, Peter O; Haraldsen, Guttorm; Bogen, Bjarne

    2005-03-01

    Gene-targeted mice have recently revealed a role for lymphocytes and interferon-gamma (IFNgamma) in conferring protection against cancer, but the mechanisms remain unclear. Here, we have characterized a successful primary antitumor immune response initiated by naive CD4+ T cells. Major histocompatibility complex class II (MHC-II)-negative myeloma cells injected subcutaneously into syngeneic mice were surrounded within 3 days by macrophages that captured tumor antigens. Within 6 days, naive myeloma-specific CD4+ T cells became activated in draining lymph nodes and subsequently migrated to the incipient tumor site. Upon recognition of tumor-derived antigenic peptides presented on MHC-II by macrophages, the myeloma-specific CD4+ T cells were reactivated and started to secrete cytokines. T cell-derived IFNgamma activated macrophages in close proximity to the tumor cells. Tumor cell growth was completely inhibited by such locally activated macrophages. These data indicate a mechanism for immunosurveillance of MHC-II-negative cancer cells by tumor-specific CD4+ T cells through collaboration with macrophages.

  9. Functions of innate immune cells and commensal bacteria in gut homeostasis.

    Science.gov (United States)

    Kayama, Hisako; Takeda, Kiyoshi

    2016-02-01

    The intestinal immune system remains unresponsive to beneficial microbes and dietary antigens while activating pro-inflammatory responses against pathogens for host defence. In intestinal mucosa, abnormal activation of innate immunity, which directs adaptive immune responses, causes the onset and/or progression of inflammatory bowel diseases. Thus, innate immunity is finely regulated in the gut. Multiple innate immune cell subsets have been identified in both murine and human intestinal lamina propria. Some innate immune cells play a key role in the maintenance of gut homeostasis by preventing inappropriate adaptive immune responses while others are associated with the pathogenesis of intestinal inflammation through development of Th1 and Th17 cells. In addition, intestinal microbiota and their metabolites contribute to the regulation of innate/adaptive immune responses. Accordingly, perturbation of microbiota composition can trigger intestinal inflammation by driving inappropriate immune responses.

  10. Enhancement and abrogation : modifications of host immune status influence IL-2 and LAK cell immunotherapy

    NARCIS (Netherlands)

    E.P. Steller (Erick)

    1988-01-01

    textabstractThis thesis will discuss the role immune cells and the host immune system can play in enhancement and abrogation of this novel immunotherapy with interleukin 2 and lymphokine-activated killer cells. Chapter 3 and 4 will discuss the scoring methods in this intraperitoneal cancer and immun

  11. HTLV-1-induced leukotriene B4 secretion by T cells promotes T cell recruitment and virus propagation.

    Science.gov (United States)

    Percher, Florent; Curis, Céline; Pérès, Eléonore; Artesi, Maria; Rosewick, Nicolas; Jeannin, Patricia; Gessain, Antoine; Gout, Olivier; Mahieux, Renaud; Ceccaldi, Pierre-Emmanuel; Van den Broeke, Anne; Duc Dodon, Madeleine; Afonso, Philippe V

    2017-06-22

    The human T-lymphotropic virus type 1 (HTLV-1) is efficiently transmitted through cellular contacts. While the molecular mechanisms of viral cell-to-cell propagation have been extensively studied in vitro, those facilitating the encounter between infected and target cells remain unknown. In this study, we demonstrate that HTLV-1-infected CD4 T cells secrete a potent chemoattractant, leukotriene B4 (LTB4). LTB4 secretion is dependent on Tax-induced transactivation of the pla2g4c gene, which encodes the cytosolic phospholipase A2 gamma. Inhibition of LTB4 secretion or LTB4 receptor knockdown on target cells reduces T-cell recruitment, cellular contact formation and virus propagation in vitro. Finally, blocking the synthesis of LTB4 in a humanized mouse model of HTLV-1 infection significantly reduces proviral load. This results from a decrease in the number of infected clones while their expansion is not impaired. This study shows the critical role of LTB4 secretion in HTLV-1 transmission both in vitro and in vivo.

  12. Hypofractionated Irradiation Has Immune Stimulatory Potential and Induces a Timely Restricted Infiltration of Immune Cells in Colon Cancer Tumors

    Science.gov (United States)

    Frey, Benjamin; Rückert, Michael; Weber, Julia; Mayr, Xaver; Derer, Anja; Lotter, Michael; Bert, Christoph; Rödel, Franz; Fietkau, Rainer; Gaipl, Udo S.

    2017-01-01

    In addition to locally controlling the tumor, hypofractionated radiotherapy (RT) particularly aims to activate immune cells in the RT-modified microenvironment. Therefore, we examined whether hypofractionated RT can activate dendritic cells (DCs), induce immune cell infiltration in tumors, and how the chronology of immune cell migration into tumors occurs to gain knowledge for future definition of radiation breaks and inclusion of immunotherapy. Colorectal cancer treatments offer only limited survival benefit, and immunobiological principles for additional therapies need to be explored with preclinical models. The impact of hypofractionated RT on CT26 colon cancer tumor cell death, migration of DCs toward supernatants (SN) of tumor cells, and activation of DCs by SN were analyzed. The subcutaneous tumor of a BALB/c-CT26 mouse model was locally irradiated with 2 × 5 Gy, the tumor volume was monitored, and the infiltration of immune cells in the tumor was determined by flow cytometry daily. Hypofractionated RT induced a mixture of apoptotic and necrotic CT26 cells, which is known to be in particular immunogenic. DCs that migrated toward SN of CT26 cells particularly upregulated the activation markers CD80 and CD86 when in contact with SN of irradiated tumor cells. After hypofractionated RT, the tumor outgrowth was significantly retarded and in the irradiated tumors an increased infiltration of macrophages (CD11bhigh/F4-80+) and DCs (MHC-II+), but only between day 5 and 10 after the first irradiation, takes place. While CD4+ T cells migrated into non-irradiated and irradiated tumors, CD8+ T cells were only found in tumors that had been irradiated and they were highly increased at day 8 after the first irradiation. Myeloid-derived suppressor cells and regulatory T cells show regular turnover in irradiated and non-irradiated tumors. Tumor cell-specific anti-IgM antibodies were enhanced in the serum of animals with irradiated tumors. We conclude that

  13. Genome-wide analysis of differential transcriptional and epigenetic variability across human immune cell types

    DEFF Research Database (Denmark)

    Ecker, Simone; Chen, Lu; Pancaldi, Vera

    2017-01-01

    Background: A healthy immune system requires immune cells that adapt rapidly to environmental challenges. This phenotypic plasticity can be mediated by transcriptional and epigenetic variability. Results: We apply a novel analytical approach to measure and compare transcriptional and epigenetic v...

  14. Recruitment of SHP-1 protein tyrosine phosphatase and signalling by a chimeric T-cell receptor-killer inhibitory receptor

    DEFF Research Database (Denmark)

    Christensen, M D; Geisler, C

    2000-01-01

    Receptors expressing the immunoreceptor tyrosine-based inhibitory motif (ITIM) in their cytoplasmic tail play an important role in the negative regulation of natural killer and B-cell activation. A subpopulation of T cells expresses the ITIM containing killer cell inhibitory receptor (KIR), which...... recognize MHC class I molecules. Following coligation of KIR with an activating receptor, the tyrosine in the ITIM is phosphorylated and the cytoplasmic protein tyrosine phosphatase SHP-1 is recruited to the ITIM via its SH2 domains. It is still not clear how SHP-1 affects T-cell receptor (TCR) signalling....... In this study, we constructed a chimeric TCR-KIR receptor. We demonstrated that SHP-1 is recruited to the chimeric TCR-KIR receptor following T-cell stimulation with either anti-TCR monoclonal antibody (MoAb) or superantigen. However, in spite of this we could not detect any effect of SHP-1 on TCR signalling...

  15. CCR5 in recruitment and activation of myeloid-derived suppressor cells in melanoma.

    Science.gov (United States)

    Umansky, Viktor; Blattner, Carolin; Gebhardt, Christoffer; Utikal, Jochen

    2017-08-01

    Malignant melanoma is characterized by the development of chronic inflammation in the tumor microenvironment, leading to the accumulation of myeloid-derived suppressor cells (MDSCs). Using ret transgenic mouse melanoma model, we found a significant migration of MDSCs expressing C-C chemokine receptor (CCR)5 into primary tumors and metastatic lymph nodes, which was correlated with tumor progression. An increased CCR5 expression on MDSCs was associated with elevated concentrations of CCR5 ligands in melanoma microenvironment. In vitro experiments showed that the upregulation of CCR5 expression on CD11b(+)Gr1(+) immature myeloid cells was induced by CCR5 ligands, IL-6, GM-CSF, and other inflammatory factors. Furthermore, CCR5(+) MDSCs infiltrating melanoma lesions displayed a stronger immunosuppressive pattern than their CCR5(-) counterparts. Targeting CCR5/CCR5 ligand signaling via a fusion protein mCCR5-Ig, which selectively binds and neutralizes all three CCR5 ligands, increased the survival of tumor-bearing mice. This was associated with a reduced migration and immunosuppressive potential of tumor MDSCs. In melanoma patients, circulating CCR5(+) MDSCs were increased as compared to healthy donors. Like in melanoma-bearing mice, we observed an enrichment of these cells and CCR5 ligands in tumors as compared to the peripheral blood. Our findings define a critical role for CCR5 not only in the recruitment but also in the activation of MDSCs in tumor lesions, suggesting that novel strategies of melanoma treatment could be based on blocking CCR5/CCR5 ligand interactions.

  16. Kaposi Sarcoma Herpesvirus (KSHV Latency-Associated Nuclear Antigen (LANA recruits components of the MRN (Mre11-Rad50-NBS1 repair complex to modulate an innate immune signaling pathway and viral latency.

    Directory of Open Access Journals (Sweden)

    Giuseppe Mariggiò

    2017-04-01

    Full Text Available Kaposi Sarcoma Herpesvirus (KSHV, a γ2-herpesvirus and class 1 carcinogen, is responsible for at least three human malignancies: Kaposi Sarcoma (KS, Primary Effusion Lymphoma (PEL and Multicentric Castleman's Disease (MCD. Its major nuclear latency protein, LANA, is indispensable for the maintenance and replication of latent viral DNA in infected cells. Although LANA is mainly a nuclear protein, cytoplasmic isoforms of LANA exist and can act as antagonists of the cytoplasmic DNA sensor, cGAS. Here, we show that cytosolic LANA also recruits members of the MRN (Mre11-Rad50-NBS1 repair complex in the cytosol and thereby inhibits their recently reported role in the sensing of cytoplasmic DNA and activation of the NF-κB pathway. Inhibition of NF-κB activation by cytoplasmic LANA is accompanied by increased lytic replication in KSHV-infected cells, suggesting that MRN-dependent NF-κB activation contributes to KSHV latency. Cytoplasmic LANA may therefore support the activation of KSHV lytic replication in part by counteracting the activation of NF-κB in response to cytoplasmic DNA. This would complement the recently described role of cytoplasmic LANA in blocking an interferon response triggered by cGAS and thereby promoting lytic reactivation. Our findings highlight a second point at which cytoplasmic LANA interferes with the innate immune response, as well as the importance of the recently discovered role of cytoplasmic MRN complex members as innate sensors of cytoplasmic DNA for the control of KSHV replication.

  17. The Consequence of Immune Suppressive Cells in the Use of Therapeutic Cancer Vaccines and Their Importance in Immune Monitoring

    Directory of Open Access Journals (Sweden)

    Matteo Vergati

    2011-01-01

    Full Text Available Evaluating the number, phenotypic characteristics, and function of immunosuppressive cells in the tumor microenvironment and peripheral blood could elucidate the antitumor immune response and provide information to evaluate the efficacy of cancer vaccines. Further studies are needed to evaluate the correlation between changes in immunosuppressive cells and clinical outcomes of patients in cancer vaccine clinical trials. This paper focuses on the role of T-regulatory cells, myeloid-derived suppressor cells, and tumor-associated macrophages in cancer and cancer immunotherapy and their role in immune monitoring.

  18. Immune Thrombocytopenia in a Child with T Cell Lymphoblastic Lymphoma

    Directory of Open Access Journals (Sweden)

    Kayo Tokeji

    2016-01-01

    Full Text Available We describe the case of a 13-year-old boy who presented with persistent thrombocytopenia during maintenance chemotherapy with mercaptopurine and methotrexate for T cell lymphoblastic lymphoma. He was diagnosed with immune thrombocytopenia (ITP after thorough investigations for the relapse of lymphoma and was successfully treated with immunoglobulin and steroids. ITP is known to be associated with chronic lymphocytic leukemia, Hodgkin lymphoma, and various types of non-Hodgkin lymphoma but rarely with T cell non-Hodgkin lymphoma or in children. Diagnosis of ITP with lymphoma is challenging due to the many factors affecting platelet counts, and ITP often complicates the diagnosis or treatment course of lymphoma. The underlying mechanism of ITP with NHL is still unclear. Drug-induced immunomodulation with a reduction of regulatory T cells might have contributed to the development of ITP in our case.

  19. Annexin A8 controls leukocyte recruitment to activated endothelial cells via cell surface delivery of CD63

    Science.gov (United States)

    Poeter, Michaela; Brandherm, Ines; Rossaint, Jan; Rosso, Gonzalo; Shahin, Victor; Skryabin, Boris V.; Zarbock, Alexander; Gerke, Volker; Rescher, Ursula

    2014-04-01

    To enable leukocyte adhesion to activated endothelium, the leukocyte receptor P-selectin is released from Weibel-Palade bodies (WPB) to the endothelial cell surface where it is stabilized by CD63. Here we report that loss of annexin A8 (anxA8) in human umbilical vein endothelial cells (HUVEC) strongly decreases cell surface presentation of CD63 and P-selectin, with a concomitant reduction in leukocyte rolling and adhesion. We confirm the compromised leukocyte adhesiveness in inflammatory-activated endothelial venules of anxA8-deficient mice. We find that WPB of anxA8-deficient HUVEC contain less CD63, and that this is caused by improper transport of CD63 from late multivesicular endosomes to WPB, with CD63 being retained in intraluminal vesicles. Consequently, reduced CD63 cell surface levels are seen following WPB exocytosis, resulting in enhanced P-selectin re-internalization. Our data support a model in which anxA8 affects leukocyte recruitment to activated endothelial cells by supplying WPB with sufficient amounts of the P-selectin regulator CD63.

  20. Immunity

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920630 Effects of the spleen on immunestate of patients with gastric cancer.QIUDengbo (仇登波), et al. Dept General Surg,Union Hosp, Tongji Med Univ, Wuhan, 430022.Natl Med J China 1992; 72(6): 334-337. For analysing the effects of the spleen on im-mune state of gastric cancer patients.T-lym-

  1. An Engineered Herpesvirus Activates Dendritic Cells and Induces Protective Immunity

    Science.gov (United States)

    Ma, Yijie; Chen, Min; Jin, Huali; Prabhakar, Bellur S.; Valyi-Nagy, Tibor; He, Bin

    2017-01-01

    Herpes simplex viruses (HSV) are human pathogens that switch between lytic and latent infection. While attenuated HSV is explored for vaccine, the underlying event remains poorly defined. Here we report that recombinant HSV-1 with a mutation in the γ134.5 protein, a virulence factor, stimulates dendritic cell (DC) maturation which is dependent on TANK-binding kinase 1 (TBK1). When exposed to CD11+ DCs, the mutant virus that lacks the amino terminus of γ134.5 undergoes temporal replication without production of infectious virus. Mechanistically, this leads to sequential phosphorylation of interferon regulatory factor 3 (IRF3) and p65/RelA. In correlation, DCs up-regulate the expression of co-stimulatory molecules and cytokines. However, selective inhibition of TBK1 precludes phosphorylation of IRF3 and subsequent DC activation by the γ134.5 mutant. Herein, the γ134.5 mutant is immune-stimulatory and non-destructive to DCs. Remarkably, upon immunization the γ134.5 mutant induces protection against lethal challenge by the wild type virus, indicative of its vaccine potential. Furthermore, CD11+ DCs primed by the γ134.5 mutant in vivo mediate protection upon adoptive transfer. These results suggest that activation of TBK1 by engineered HSV is crucial for DC maturation, which may contribute to protective immunity. PMID:28150813

  2. S-nitrosylation/Denitrosylation and Apoptosis of Immune Cells

    Institute of Scientific and Technical Information of China (English)

    Shaojin Duan; Chang Chen

    2007-01-01

    Nitric oxide (NO) as an immunoregulatory molecule, predominantly depending on S-nitrosylation, acts as a versatile player that executes its regulation and signal transduction for exerting its multi-functions and pleiotropy.Apoptosis of immune cells is an intricate process coupled with positive/negative selection depending on integrated diverse endogenous and exogenous signals and functions to sustain homeostasis in the immune system. Here, the dual roles of NO depending on its concentration in apoptosis are reviewed, breeding up a switch mode in the apoptotic process. Following comments of different switches from apoptosis-death, a new finding of checkpoint(early fluorescence point) of GSNO-initiated thymocyte apoptosis and NOS-GSNOR double control are highlighted.Moreover, S-nitrosylation/denitrosylation, being as a redox switch, logically approaches to networks of metabolism itself and further accesses the neuroendicrine-immune-free radical network as a whole. Moreover, the host defense mediated by NO on pathogens, via protein S-nitrosylation are also discussed.

  3. Skin effector memory T cells do not recirculate and provide immune protection in alemtuzumab-treated CTCL patients

    Science.gov (United States)

    Clark, Rachael A.; Watanabe, Rei; Teague, Jessica E.; Schlapbach, Christoph; Tawa, Marianne C.; Adams, Natalie; Dorosario, Andrew A.; Chaney, Keri S.; Cutler, Corey S.; LeBoeuf, Nicole R.; Carter, Joi B.; Fisher, David C.; Kupper, Thomas S.

    2012-01-01

    CTCL is a cancer of skin homing T cells with variants that include leukemic CTCL (L-CTCL), a malignancy of central memory T cells (TCM), and mycosis fungoides (MF), a malignancy of skin resident effector memory T cells (TEM). We report that low-dose alemtuzumab (αCD52) effectively treated patients with refractory L-CTCL but not MF. Alemtuzumab depleted all T cells in blood and depleted both benign and malignant TCM from skin, but a diverse population of skin resident TEM remained in skin after therapy. T-cell depletion with alemtuzumab required the presence of neutrophils, a cell type frequent in blood but rare in normal skin. These data suggest that TCM were depleted because they recirculate between the blood and skin whereas skin resident TEM were spared because they are sessile and non-recirculating. After alemtuzumab treatment, skin T cells produced lower amounts of IL-4 and higher amounts of IFNγ. Moreover, there was a marked lack of infections in alemtuzumab-treated L-CTCL patients despite the complete absence of T cells in blood, suggesting that skin resident TEM can protect the skin from pathogens even in the absence of T cell recruitment from the circulation. Together, these data suggest that alemtuzumab may treat refractory L-CTCL without severely compromising the immune response to infection by depleting circulating TCM but sparing the skin resident TEM that provide local immune protection of the skin. PMID:22261031

  4. The small GTPase Rab8 interacts with VAMP-3 to regulate the delivery of recycling T-cell receptors to the immune synapse.

    Science.gov (United States)

    Finetti, Francesca; Patrussi, Laura; Galgano, Donatella; Cassioli, Chiara; Perinetti, Giuseppe; Pazour, Gregory J; Baldari, Cosima T

    2015-07-15

    IFT20, a component of the intraflagellar transport (IFT) system that controls ciliogenesis, regulates immune synapse assembly in the non-ciliated T-cell by promoting T-cell receptor (TCR) recycling. Here, we have addressed the role of Rab8 (for which there are two isoforms Rab8a and Rab8b), a small GTPase implicated in ciliogenesis, in TCR traffic to the immune synapse. We show that Rab8, which colocalizes with IFT20 in Rab11(+) endosomes, is required for TCR recycling. Interestingly, as opposed to in IFT20-deficient T-cells, TCR(+) endosomes polarized normally beneath the immune synapse membrane in the presence of dominant-negative Rab8, but were unable to undergo the final docking or fusion step. This could be accounted for by the inability of the vesicular (v)-SNARE VAMP-3 to cluster at the immune synapse in the absence of functional Rab8, which is responsible for its recruitment. Of note, and similar to in T-cells, VAMP-3 interacts with Rab8 at the base of the cilium in NIH-3T3 cells, where it regulates ciliary growth and targeting of the protein smoothened. The results identify Rab8 as a new player in vesicular traffic to the immune synapse and provide insight into the pathways co-opted by different cell types for immune synapse assembly and ciliogenesis.

  5. Cell-mediated immune responses in rainbow trout after DNA immunization against the viral hemorrhagic septicemia virus

    DEFF Research Database (Denmark)

    Utke, Katrin; Kock, Holger; Schuetze, Heike

    2008-01-01

    To identify viral proteins that induce cell-mediated cytotoxicity (CMC) against viral hemorrhagic septicemia virus (VHSV)-infected cells, rainbow trout were immunized with DNA vectors encoding the glycoprotein G or the nucleocapsid protein N of VHSV. The G protein was a more potent trigger...... injection site rather than to injection sites of heterologous vaccines, suggesting the antigen specificity of homing. By demonstrating CMC responses to distinct viral proteins and homing in rainbow trout, these results substantially contribute to the understanding of the teleost immune system....... of cytotoxic cells than the N protein. Peripheral blood leukocytes (PBL) isolated from trout immunized against the G protein killed both VHSV-infected MHC class I matched (RTG-2) and VHSV-infected xenogeneic (EPC) target cells, suggesting the involvement of both cytotoxic T lymphocytes (CTL) and NK cells...

  6. Tim-3: an activation marker and activation limiter of innate immune cells.

    Science.gov (United States)

    Han, Gencheng; Chen, Guojiang; Shen, Beifen; Li, Yan

    2013-12-10

    Tim-3 was initially identified on activated Th1, Th17, and Tc1 cells and induces T cell death or exhaustion after binding to its ligand, Gal-9. The observed relationship between dysregulated Tim-3 expression on T cells and the progression of many clinical diseases has identified this molecule as an important target for intervention in adaptive immunity. Recent data have shown that it also plays critical roles in regulating the activities of macrophages, monocytes, dendritic cells, mast cells, natural killer cells, and endothelial cells. Although the underlying mechanisms remain unclear, dysregulation of Tim-3 expression on these innate immune cells leads to an excessive or inhibited inflammatory response and subsequent autoimmune damage or viral or tumor evasion. In this review, we focus on the expression and function of Tim-3 on innate immune cells and discuss (1) how Tim-3 is expressed and regulated on different innate immune cells; (2) how it affects the activity of different innate immune cells; and (3) how dysregulated Tim-3 expression on innate immune cells affects adaptive immunity and disease progression. Tim-3 is involved in the optimal activation of innate immune cells through its varied expression. A better understanding of the physiopathological role of the Tim-3 pathway in innate immunity will shed new light on the pathogenesis of clinical diseases, such as autoimmune diseases, chronic viral infections, and cancer, and suggest new approaches to intervention.

  7. Tim-3: An activation marker and activation limiter of innate immune cells

    Directory of Open Access Journals (Sweden)

    Gencheng eHan

    2013-12-01

    Full Text Available Tim-3 was initially identified on activated Th1, Th17, and Tc1 cells and induces T cell death or exhaustion after binding to its ligand, Gal-9. The observed relationship between dysregulated Tim-3 expression on T cells and the progression of many clinical diseases has identified this molecule as an important target for intervention in adaptive immunity. Recent data have shown that it also plays critical roles in regulating the activities of macrophages, monocytes, dendritic cells, mast cells, natural killer cells, and endothelial cells. Although the underlying mechanisms remain unclear, dysregulation of Tim-3 expression on these innate immune cells leads to an excessive or inhibited inflammatory response and subsequent autoimmune damage or viral or tumor evasion. In this review, we focus on the expression and function of Tim-3 on innate immune cells and discuss 1 how Tim-3 is expressed and regulated on different innate immune cells; 2 how it affects the activity of different innate immune cells; and 3 how dysregulated Tim-3 expression on innate immune cells affects adaptive immunity and disease progression. Tim-3 is involved in the optimal activation of innate immune cells through its varied expression. A better understanding of the physiopathological role of the Tim-3 pathway in innate immunity will shed new light on the pathogenesis of clinical diseases, such as autoimmune diseases, chronic viral infections, and cancer, and suggest new approaches to intervention.

  8. Prenatal cadmium exposure alters postnatal immune cell development and function

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Miranda L.; Holásková, Ida; Elliott, Meenal; Brundage, Kathleen M.; Schafer, Rosana; Barnett, John B., E-mail: jbarnett@hsc.wvu.edu

    2012-06-01

    Cadmium (Cd) is generally found in low concentrations in the environment due to its widespread and continual use, however, its concentration in some foods and cigarette smoke is high. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports of immunomodulatory effects of prenatal exposure to Cd. This study was designed to investigate the effects of prenatal exposure to Cd on the immune system of the offspring. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at two time points following birth (2 and 7 weeks of age). Thymocyte and splenocyte phenotypes were analyzed by flow cytometry. Prenatal Cd exposure did not affect thymocyte populations at 2 and 7 weeks of age. In the spleen, the only significant effect on phenotype was a decrease in the number of macrophages in male offspring at both time points. Analysis of cytokine production by stimulated splenocytes demonstrated that prenatal Cd exposure decreased IL-2 and IL-4 production by cells from female offspring at 2 weeks of age. At 7 weeks of age, splenocyte IL-2 production was decreased in Cd-exposed males while IFN-γ production was decreased from both male and female Cd-exposed offspring. The ability of the Cd-exposed offspring to respond to immunization with a S. pneumoniae vaccine expressing T-dependent and T-independent streptococcal antigens showed marked increases in the levels of both T-dependent and T-independent serum antibody levels compared to control animals. CD4{sup +}FoxP3{sup +}CD25{sup +} (nTreg) cell percentages were increased in the spleen and thymus in all Cd-exposed offspring except in the female spleen where a decrease was seen. CD8{sup +}CD223{sup +} T cells were markedly decreased in the spleens in all offspring at 7 weeks of age. These findings suggest that even very low levels of Cd exposure during gestation can

  9. Critical Role of Myeloid-Derived Suppressor Cells in Tumor-Induced Liver Immune Suppression through Inhibition of NKT Cell Function

    Science.gov (United States)

    Zhang, Hongru; Li, Zheng; Wang, Li; Tian, Gaofei; Tian, Jun; Yang, Zishan; Cao, Guangchao; Zhou, Hong; Zhao, Liqing; Wu, Zhenzhou; Yin, Zhinan

    2017-01-01

    Metastasis followed by the tumor development is the primary cause of death for cancer patients. However, the underlying molecular mechanisms of how the growth of tumor resulted in the immune suppression, especially at the blood-enriched organ such as liver, were largely unknown. In this report, we studied the liver immune response of tumor-bearing (TB) mice using concanavalin A (Con A)-induced hepatitis model. We demonstrated that TB mice displayed an immune suppression phenotype, with attenuated alanine aminotransferase levels and liver damage upon Con A treatment. We also elucidated that large amounts of myeloid-derived suppressor cells (MDSCs) being influx into the liver in TB mice and these MDSCs were essential for liver immune suppression through both depletion and reconstitution approaches. We further determined that these MDSCs selectively suppressed the IFN-γ production deriving from NKT cells through membrane-bound transforming growth factor β (TGF-β). Finally, we defined a tumor-derived TGF-β-triggered CXCL1/2/5- and CXCR2-dependent recruitment of MDSC into the liver. In summary, our results defined a novel mechanism of liver immune suppression triggered by growing living tumor and provided possible therapeutic targets against these MDSCs.

  10. How stem cells speak with host immune cells in inflammatory brain diseases.

    Science.gov (United States)

    Pluchino, Stefano; Cossetti, Chiara

    2013-09-01

    Advances in stem cell biology have raised great expectations that diseases and injuries of the central nervous system (CNS) may be ameliorated by the development of non-hematopoietic stem cell medicines. Yet, the application of adult stem cells as CNS therapeutics is challenging and the interpretation of some of the outcomes ambiguous. In fact, the initial idea that stem cell transplants work only via structural cell replacement has been challenged by the observation of consistent cellular signaling between the graft and the host. Cellular signaling is the foundation of coordinated actions and flexible responses, and arises via networks of exchanging and interacting molecules that transmit patterns of information between cells. Sustained stem cell graft-to-host communication leads to remarkable trophic effects on endogenous brain cells and beneficial modulatory actions on innate and adaptive immune responses in vivo, ultimately promoting the healing of the injured CNS. Among a number of adult stem cell types, mesenchymal stem cells (MSCs) and neural stem/precursor cells (NPCs) are being extensively investigated for their ability to signal to the immune system upon transplantation in experimental CNS diseases. Here, we focus on the main cellular signaling pathways that grafted MSCs and NPCs use to establish a therapeutically relevant cross talk with host immune cells, while examining the role of inflammation in regulating some of the bidirectionality of these communications. We propose that the identification of the players involved in stem cell signaling might contribute to the development of innovative, high clinical impact therapeutics for inflammatory CNS diseases.

  11. Extreme CD8 T cell requirements for anti-malarial liver-stage immunity following immunization with radiation attenuated sporozoites.

    Directory of Open Access Journals (Sweden)

    Nathan W Schmidt

    2010-07-01

    Full Text Available Radiation-attenuated Plasmodium sporozoites (RAS are the only vaccine shown to induce sterilizing protection against malaria in both humans and rodents. Importantly, these "whole-parasite" vaccines are currently under evaluation in human clinical trials. Studies with inbred mice reveal that RAS-induced CD8 T cells targeting liver-stage parasites are critical for protection. However, the paucity of defined T cell epitopes for these parasites has precluded precise understanding of the specific characteristics of RAS-induced protective CD8 T cell responses. Thus, it is not known whether quantitative or qualitative differences in RAS-induced CD8 T cell responses underlie the relative resistance or susceptibility of immune inbred mice to sporozoite challenge. Moreover, whether extraordinarily large CD8 T cell responses are generated and required for protection following RAS immunization, as has been described for CD8 T cell responses following single-antigen subunit vaccination, remains unknown. Here, we used surrogate T cell activation markers to identify and track whole-parasite, RAS-vaccine-induced effector and memory CD8 T cell responses. Our data show that the differential susceptibility of RAS-immune inbred mouse strains to Plasmodium berghei or P. yoelii sporozoite challenge does not result from host- or parasite-specific decreases in the CD8 T cell response. Moreover, the surrogate activation marker approach allowed us for the first time to evaluate CD8 T cell responses and protective immunity following RAS-immunization in outbred hosts. Importantly, we show that compared to a protective subunit vaccine that elicits a CD8 T cell response to a single epitope, diversifying the targeted antigens through whole-parasite RAS immunization only minimally, if at all, reduced the numerical requirements for memory CD8 T cell-mediated protection. Thus, our studies reveal that extremely high frequencies of RAS-induced memory CD8 T cells are required, but

  12. NKT cell self-reactivity: evolutionary master key of immune homeostasis?

    DEFF Research Database (Denmark)

    Navikas, Shohreh

    2011-01-01

    Complex immune responses have evolved to protect multicellular organisms against the invasion of pathogens. This has exerted strong developmental pressure for specialized functions that can also limit damage to self-tissue. Two arms of immunity, the innate and adaptive immune system, have evolved...... for quick, non-specific immune responses to pathogens and more efficient, long-lasting ones upon specific recognition of recurrent pathogens. Specialized cells have arisen as the sentinels of these functions, including macrophages, natural killer (NK), and T and B-lymphocytes. Interestingly, a population...... of immune cells that can exert both of these complex functions, NKT cells, not only share common functions but also exhibit shared cell surface markers of cells of both arms of the immune system. These features, in combination with sophisticated maintenance of immune homeostasis, will be discussed...

  13. Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation

    Directory of Open Access Journals (Sweden)

    Asiel Arce-Sillas

    2016-01-01

    Full Text Available T regulatory cells play a key role in the control of the immune response, both in health and during illness. While the mechanisms through which T regulatory cells exert their function have been extensively described, their molecular effects on effector cells have received little attention. Thus, this revision is aimed at summarizing our current knowledge on those regulation mechanisms on the target cells from a molecular perspective.

  14. Endogenous Stem Cells Were Recruited by Defocused Low-Energy Shock Wave in Treating Diabetic Bladder Dysfunction.

    Science.gov (United States)

    Jin, Yang; Xu, Lina; Zhao, Yong; Wang, Muwen; Jin, Xunbo; Zhang, Haiyang

    2016-12-05

    Defocused low-energy shock wave (DLSW) has been shown effects on activating mesenchymal stromal cells (MSCs) in vitro. In this study, recruitment of endogenous stem cells was firstly examined as an important pathway during the healing process of diabetic bladder dysfunction (DBD) treated by DLSW in vivo. Neonatal rats received intraperitoneal injection of 5-ethynyl-2-deoxyuridine (EdU) and then DBD rat model was created by injecting streptozotocin. Four weeks later, DLSW treatment was performed. Afterward, their tissues were examined by histology. Meanwhile, adipose tissue-derived stem cells (ADSCs) were treated by DLSW in vitro. Results showed DLSW ameliorated voiding function of diabetic rats by recruiting EdU(+)Stro-1(+)CD34(-) endogenous stem cells to release abundant nerve growth factor (NGF) and vascular endothelial growth factor (VEGF). Some EdU(+) cells overlapped with staining of smooth muscle actin. After DLSW treatment, ADSCs showed higher migration ability, higher expression level of stromal cell-derived factor-1 and secreted more NGF and VEGF. In conclusion, DLSW could ameliorate DBD by recruiting endogenous stem cells. Beneficial effects were mediated by secreting NGF and VEGF, resulting into improved innervation and vascularization in bladder.

  15. [Significance of regulatory B cells in nosogenesis of immune thrombocytopenia].

    Science.gov (United States)

    Li, Xin; Wang, Fang; Ding, Kai Yang; Dai, Lan

    2014-04-01

    This study was aimed to investigate the role of regulatory B cells (Breg) in pathogenesis of immune thrombocytopenia (ITP) and its clinical significance. A total of 35 ITP patients and 20 normal controls were enrolled in this study. The expression of CD19(+)CD24(hi)CD38(hi) B cells was detected by flow cytometry and the expression of IL-10 mRNA and TGF-β1 mRNA was assayed by RT-PCR. The results indicated that the expression level of CD19(+)CD24(hi)CD38(hi) B cells in peripheral blood of newly diagnosed ITP patients was obviously lower than that in normal controls (P < 0.05); the expression level of CD19(+)CD24(hi)CD38(hi) B cells in ITP patients with increased platelet count after treatment was higher than that before treatment (P < 0.05); the expression level of IL-10 mRNA in newly diagnosed ITP patients was significantly lower than that the in normal controls (P < 0.05), the expression level of TGF-β1 mRNA in newly diagnosed ITP patients increases as compared with normal controls (P < 0.05), after treatment with DXM the expression of IL-10 mRNA was enhanced, the expression of TGF-β1 mRNA was reduced as compared with expression level before treatment (P < 0.05). It is concluded that the Breg cells may play an important role in the pathogenesis of ITP via humoral immunity and its regulation of T lymphocytes.

  16. Human Gastric Epithelial Cells Contribute to Gastric Immune Regulation by Providing Retinoic Acid to Dendritic Cells

    OpenAIRE

    Bimczok, Diane; John Y. Kao; Zhang, Min; Cochrun, Steven; Mannon, Peter; Peter, Shajan; Wilcox, Charles M.; Mönkemüller, Klaus E; Harris, Paul R.; Grams, Jayleen M.; Stahl, Richard D.; Smith, Phillip D.; Smythies, Lesley E.

    2014-01-01

    Despite the high prevalence of chronic gastritis caused by H. pylori, the gastric mucosa has received little investigative attention as a unique immune environment. Here, we analyzed whether retinoic acid (RA), an important homeostatic factor in the small intestinal mucosa, also contributes to gastric immune regulation. We report that human gastric tissue contains high levels of the RA precursor molecule, retinol, and that gastric epithelial cells express both RA biosynthesis genes and RA res...

  17. Decidual stromal cells recruit Th17 cells into decidua to promote proliferation and invasion of human trophoblast cells by secreting IL-17.

    Science.gov (United States)

    Wu, Hai-Xia; Jin, Li-Ping; Xu, Bing; Liang, Shan-Shan; Li, Da-Jin

    2014-05-01

    T helper 17 (Th17) cells have both regulatory and protective roles in physiological conditions. The Th17 subset and the cytokine interleukin-17A (IL-17A) have been implicated in the pathogenesis of certain autoimmune diseases, several types of cancer and allograft rejection. However, the role of Th17 cells at the maternal/fetal interface remains unknown. Here, we demonstrate that Th17 cells are present in decidua and are increased in the peripheral blood of 10 clinically normal pregnancies based on intracellular cytokine analysis. Our results suggest a potential role of Th17 cells in sustaining pregnancy in humans. Furthermore, we demonstrate that decidual stromal cells (DSCs) but not trophoblast cells recruit peripheral Th17 cells into the decidua by secreting CCL2. The recruited Th17 cells promote proliferation and invasion and inhibit the apoptosis of human trophoblast cells by secreting IL-17 during the first trimester of pregnancy. These findings indicate a novel role for Th17 cells in controlling the maternal-fetal relationship and placenta development.

  18. The immune-body cytokine network defines a social architecture of cell interactions

    Directory of Open Access Journals (Sweden)

    Alon Uri

    2006-10-01

    Full Text Available Abstract Background Three networks of intercellular communication can be associated with cytokine secretion; one limited to cells of the immune system (immune cells, one limited to parenchymal cells of organs and tissues (body cells, and one involving interactions between immune and body cells (immune-body interface. These cytokine connections determine the inflammatory response to injury and subsequent healing as well as the biologic consequences of the adaptive immune response to antigens. We informatically probed the cytokine database to uncover the underlying network architecture of the three networks. Results We now report that the three cytokine networks are among the densest of complex networks yet studied, and each features a characteristic profile of specific three-cell motifs. Some legitimate cytokine connections are shunned (anti-motifs. Certain immune cells can be paired by their input-output positions in a cytokine architecture tree of five tiers: macrophages (MΦ and B cells (BC comprise the first tier; the second tier is formed by T helper 1 (Th1 and T helper 2 (Th2 cells; the third tier includes dendritic cells (DC, mast cells (MAST, Natural Killer T cells (NK-T and others; the fourth tier is formed by neutrophils (NEUT and Natural Killer cells (NK; and the Cytotoxic T cell (CTL stand alone as a fifth tier. The three-cell cytokine motif architecture of immune system cells places the immune system in a super-family that includes social networks and the World Wide Web. Body cells are less clearly stratified, although cells involved in wound healing and angiogenesis are most highly interconnected with immune cells. Conclusion Cytokine network architecture creates an innate cell-communication platform that organizes the biologic outcome of antigen recognition and inflammation. Informatics sheds new light on immune-body systems organization. Reviewers This article was reviewed by Neil Greenspan, Matthias von Herrath and Anne Cooke.

  19. Humoral and cell-mediated immune responses in DNA immunized mink challenged with wild-type canine distemper virus

    DEFF Research Database (Denmark)

    Nielsen, Line; Søgaard, Mette; Karlskov-Mortensen, Peter

    2009-01-01

    The aim of the study was to investigate the different phases of the immune response after DNA immunization with the hemagglutinin and nucleoprotein genes from canine distemper virus (CDV). Although attenuated live CDV vaccines have effectively reduced the incidence of disease, canine distemper...... is still a problem worldwide. The broad host range of CDV creates a constant viral reservoir among wildlife animals. Our results demonstrated early humoral and cell-mediated immune responses (IFN-gamma) in DNA vaccinated mink compared to mock-vaccinated mink after challenge with a Danish wild-type CDV...

  20. Genomic Correlates of Immune-Cell Infiltrates in Colorectal Carcinoma

    Directory of Open Access Journals (Sweden)

    Marios Giannakis

    2016-04-01

    Full Text Available Large-scale genomic characterization of tumors from prospective cohort studies may yield new insights into cancer pathogenesis. We performed whole-exome sequencing of 619 incident colorectal cancers (CRCs and integrated the results with tumor immunity, pathology, and survival data. We identified recurrently mutated genes in CRC, such as BCL9L, RBM10, CTCF, and KLF5, that were not previously appreciated in this disease. Furthermore, we investigated the genomic correlates of immune-cell infiltration and found that higher neoantigen load was positively associated with overall lymphocytic infiltration, tumor-infiltrating lymphocytes (TILs, memory T cells, and CRC-specific survival. The association with TILs was evident even within microsatellite-stable tumors. We also found positive selection of mutations in HLA genes and other components of the antigen-processing machinery in TIL-rich tumors. These results may inform immunotherapeutic approaches in CRC. More generally, this study demonstrates a framework for future integrative molecular epidemiology research in colorectal and other malignancies.

  1. T cell immunity and vaccines against invasive fungal diseases.

    Science.gov (United States)

    Ito, James Isami

    2011-01-01

    Over the past two decades much has been learned about the immunology of invasive fungal infection, especially invasive candidiasis and invasive aspergillosis. Although quite different in their pathogenesis, the major common protective host response is Th1 mediated. It is through Th1 cytokine production that the effector cells, phagocytes, are activated to kill the fungus. A more thorough understanding of the pathogenesis of disease, the elicited protective Th1 immune response, the T cell antigen(s) which elicit this response, and the mechanism(s) whereby one can enhance, reconstitute, or circumvent the immunosuppressed state will, hopefully, lead to the development of a vaccine(s) capable of protecting even the most immunocompromised of hosts.

  2. Allergen recognition by innate immune cells: critical role of dendritic and epithelial cells

    Directory of Open Access Journals (Sweden)

    Fabian eSalazar

    2013-11-01

    Full Text Available Allergy is an exacerbated response of the immune system against non-self-proteins called allergens and is typically characterized by biased type-2 T helper cell and deleterious IgE mediated immune responses. The allergic cascade starts with the recognition of allergens by antigen presenting cells, mainly dendritic cells, culminating in mast cell sensitization and triggering. Dendritic cells have been demonstrated to play a crucial role in orchestrating allergic diseases. Using different C-type lectin receptors dendritic cells are able to recognize and internalize a number of allergens from diverse sources leading to sensitization. Furthermore, there is increasing evidence highlighting the role of epithelial cells in triggering and modulating immune responses to allergens. As well as providing a physical barrier, epithelial cells can interact with allergens and influence dendritic cells behaviour through the release of a number of Th2 promoting cytokines. In this review we will summarise current understanding of how allergens are recognised by dendritic cells and epithelial cells and what are the consequences of such interaction in the context of allergic sensitisation and downstream events leading to allergic inflammation. Better understanding of the molecular mechanisms of allergen recognition and associated signalling pathways could enable developing more effective therapeutic strategies that target the initial steps of allergic sensitisation hence hindering development or progression of allergic diseases.

  3. Hydroxytyrosol and oleuropein of olive oil inhibit mast cell degranulation induced by immune and non-immune pathways.

    Science.gov (United States)

    Persia, Fabio Andrés; Mariani, María Laura; Fogal, Teresa Hilda; Penissi, Alicia Beatriz

    2014-09-25

    The aim of this study was to determine whether hydroxytyrosol and oleuropein, the major phenols found in olives and olive oil, inhibit mast cell activation induced by immune and non-immune pathways. Purified peritoneal mast cells were preincubated in the presence of test compounds (hydroxytyrosol or oleuropein), before incubation with concanavalin A, compound 48/80 or calcium ionophore A23187. Dose-response and time-dependence studies were carried out. Comparative studies with sodium cromoglycate, a classical mast cell stabilizer, were also made. After incubation the supernatants and pellets were used to determine the β-hexosaminidase content by colorimetric reaction. The percentage of β-hexosaminidase release in each tube was calculated and taken as a measure of mast cell activation. Other samples of cell pellets were used for cell viability studies by the trypan blue dye exclusion test, or fixed for light and electron microscopy. Biochemical and morphological findings of the present study showed for the first time that hydroxytyrosol and oleuropein inhibit mast cell degranulation induced by both immune and non-immune pathways. These results suggest that olive phenols, particularly hydroxytyrosol and oleuropein, may provide insights into the development of useful tools for the prevention and treatment of mast cell-mediated disorders.

  4. Natural killer cells eradicate galectin-1-deficient glioma in the absence of adaptive immunity.

    Science.gov (United States)

    Baker, Gregory J; Chockley, Peter; Yadav, Viveka Nand; Doherty, Robert; Ritt, Michael; Sivaramakrishnan, Sivaraj; Castro, Maria G; Lowenstein, Pedro R

    2014-09-15

    Natural killer (NK) cells safeguard against early tumor formation by destroying transformed target cells in a process referred to as NK immune surveillance. However, the immune escape mechanisms used by malignant brain tumors to subvert this innate type of immune surveillance remain unclear. Here we show that malignant glioma cells suppress NK immune surveillance by overexpressing the β-galactoside-binding lectin galectin-1. Conversely, galectin-1-deficient glioma cells could be eradicated by host NK cells before the initiation of an antitumor T-cell response. In vitro experiments demonstrated that galectin-1-deficient GL26-Cit glioma cells are ∼3-fold more sensitive to NK-mediated tumor lysis than galectin-1-expressing cells. Our findings suggest that galectin-1 suppression in human glioma could improve patient survival by restoring NK immune surveillance that can eradicate glioma cells. Cancer Res; 74(18); 5079-90. ©2014 AACR. ©2014 American Association for Cancer Research.

  5. Subversion of cell-autonomous immunity and cell migration by Legionella pneumophila effectors

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    Sylvia eSimon

    2015-09-01

    Full Text Available Bacteria trigger host defense and inflammatory processes such as cytokine production, pyroptosis and the chemotactic migration of immune cells towards the source of infection. However, a number of pathogens interfere with these immune functions by producing specific so-called effector proteins, which are delivered to host cells via dedicated secretion systems. Air-borne Legionella pneumophila bacteria trigger an acute and potential fatal inflammation in the lung termed Legionnaires’ disease. The opportunistic pathogen L. pneumophila is a natural parasite of free-living amoebae, but also replicates in alveolar macrophages and accidentally infects humans. The bacteria employ the Icm/Dot type IV secretion system and as many as 300 different effector proteins to govern host cell interactions and establish in phagocytes an intracellular replication niche, the Legionella-containing vacuole. Some Icm/Dot-translocated effector proteins target cell autonomous immunity or cell migration, i.e. they interfere with (i endocytic, secretory or retrograde vesicle trafficking pathways, (ii organelle or cell motility, (iii the inflammasome and programmed cell death, or (iv the transcription factor NF-κB. Here we review recent mechanistic insights into the subversion of cellular immune functions by L. pneumophila.

  6. The role of heparanase in pulmonary cell recruitment in response to an allergic but not non-allergic stimulus.

    Science.gov (United States)

    Morris, Abigail; Wang, Bo; Waern, Ida; Venkatasamy, Radhakrishnan; Page, Clive; Schmidt, Eric P; Wernersson, Sara; Li, Jin-Ping; Spina, Domenico

    2015-01-01

    Heparanase is an endo-β-glucuronidase that specifically cleaves heparan sulfate proteoglycans in the extracellular matrix. Expression of this enzyme is increased in several pathological conditions including inflammation. We have investigated the role of heparanase in pulmonary inflammation in the context of allergic and non-allergic pulmonary cell recruitment using heparanase knockout (Hpa-/-) mice as a model. Following local delivery of LPS or zymosan, no significant difference was found in the recruitment of neutrophils to the lung between Hpa-/- and wild type (WT) control. Similarly neutrophil recruitment was not inhibited in WT mice treated with a heparanase inhibitor. However, in allergic inflammatory models, Hpa-/- mice displayed a significantly reduced eosinophil (but not neutrophil) recruitment to the airways and this was also associated with a reduction in allergen-induced bronchial hyperresponsiveness, indicating that heparanase expression is associated with allergic reactions. This was further demonstrated by pharmacological treatment with a heparanase inhibitor in the WT allergic mice. Examination of lung specimens from patients with different severity of chronic obstructive pulmonary disease (COPD) found increased heparanase expression. Thus, it is established that heparanase contributes to allergen-induced eosinophil recruitment to the lung and could provide a novel therapeutic target for the development of anti-inflammatory drugs for the treatment of asthma and other allergic diseases.

  7. The role of heparanase in pulmonary cell recruitment in response to an allergic but not non-allergic stimulus.

    Directory of Open Access Journals (Sweden)

    Abigail Morris

    Full Text Available Heparanase is an endo-β-glucuronidase that specifically cleaves heparan sulfate proteoglycans in the extracellular matrix. Expression of this enzyme is increased in several pathological conditions including inflammation. We have investigated the role of heparanase in pulmonary inflammation in the context of allergic and non-allergic pulmonary cell recruitment using heparanase knockout (Hpa-/- mice as a model. Following local delivery of LPS or zymosan, no significant difference was found in the recruitment of neutrophils to the lung between Hpa-/- and wild type (WT control. Similarly neutrophil recruitment was not inhibited in WT mice treated with a heparanase inhibitor. However, in allergic inflammatory models, Hpa-/- mice displayed a significantly reduced eosinophil (but not neutrophil recruitment to the airways and this was also associated with a reduction in allergen-induced bronchial hyperresponsiveness, indicating that heparanase expression is associated with allergic reactions. This was further demonstrated by pharmacological treatment with a heparanase inhibitor in the WT allergic mice. Examination of lung specimens from patients with different severity of chronic obstructive pulmonary disease (COPD found increased heparanase expression. Thus, it is established that heparanase contributes to allergen-induced eosinophil recruitment to the lung and could provide a novel therapeutic target for the development of anti-inflammatory drugs for the treatment of asthma and other allergic diseases.

  8. Lipid body accumulation alters calcium signaling dynamics in immune cells.

    Science.gov (United States)

    Greineisen, William E; Speck, Mark; Shimoda, Lori M N; Sung, Carl; Phan, Nolwenn; Maaetoft-Udsen, Kristina; Stokes, Alexander J; Turner, Helen

    2014-09-01

    There is well-established variability in the numbers of lipid bodies (LB) in macrophages, eosinophils, and neutrophils. Similarly to the steatosis observed in adipocytes and hepatocytes during hyperinsulinemia and nutrient overload, immune cell LB hyper-accumulate in response to bacterial and parasitic infection and inflammatory presentations. Recently we described that hyperinsulinemia, both in vitro and in vivo, drives steatosis and phenotypic changes in primary and transformed mast cells and basophils. LB reach high numbers in these steatotic cytosols, and here we propose that they could dramatically impact the transcytoplasmic signaling pathways. We compared calcium release and influx responses at the population and single cell level in normal and steatotic model mast cells. At the population level, all aspects of FcɛRI-dependent calcium mobilization, as well as activation of calcium-dependent downstream signaling targets such as NFATC1 phosphorylation are suppressed. At the single cell level, we demonstrate that LB are both sources and sinks of calcium following FcɛRI cross-linking. Unbiased analysis of the impact of the presence of LB on the rate of trans-cytoplasmic calcium signals suggest that LB enrichment accelerates calcium propagation, which may reflect a Bernoulli effect. LB abundance thus impacts this fundamental signaling pathway and its downstream targets.

  9. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

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    Enrique Montalvillo

    2014-05-01

    Full Text Available The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity. Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  10. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system.

    Science.gov (United States)

    Montalvillo, Enrique; Garrote, José Antonio; Bernardo, David; Arranz, Eduardo

    2014-05-01

    The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity.Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  11. Crosstalk between Innate Lymphoid Cells and Other Immune Cells in the Tumor Microenvironment

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    Fabian Flores-Borja

    2016-01-01

    Full Text Available Our knowledge and understanding of the tumor microenvironment (TME have been recently expanded with the recognition of the important role of innate lymphoid cells (ILC. Three different groups of ILC have been described based on their ability to produce cytokines that mediate the interactions between innate and adaptive immune cells in a variety of immune responses in infection, allergy, and autoimmunity. However, recent evidence from experimental models and clinical studies has demonstrated that ILC contribute to the mechanisms that generate suppressive or tolerant environments that allow tumor regression or progression. Defining the complex network of interactions and crosstalk of ILC with other immune cells and understanding the specific contributions of each type of ILC leading to tumor development will allow the manipulation of their function and will be important to develop new interventions and therapeutic strategies.

  12. Crosstalk between Innate Lymphoid Cells and Other Immune Cells in the Tumor Microenvironment

    Science.gov (United States)

    Irshad, Sheeba; Gordon, Peter; Wong, Felix; Sheriff, Ibrahim; Tutt, Andrew; Ng, Tony

    2016-01-01

    Our knowledge and understanding of the tumor microenvironment (TME) have been recently expanded with the recognition of the important role of innate lymphoid cells (ILC). Three different groups of ILC have been described based on their ability to produce cytokines that mediate the interactions between innate and adaptive immune cells in a variety of immune responses in infection, allergy, and autoimmunity. However, recent evidence from experimental models and clinical studies has demonstrated that ILC contribute to the mechanisms that generate suppressive or tolerant environments that allow tumor regression or progression. Defining the complex network of interactions and crosstalk of ILC with other immune cells and understanding the specific contributions of each type of ILC leading to tumor development will allow the manipulation of their function and will be important to develop new interventions and therapeutic strategies. PMID:27882334

  13. Dynamic visualization of dendritic cell-antigen interactions in the skin following transcutaneous immunization.

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    Teerawan Rattanapak

    Full Text Available Delivery of vaccines into the skin provides many advantages over traditional parenteral vaccination and is a promising approach due to the abundance of antigen presenting cells (APC residing in the skin including Langerhans cells (LC and dermal dendritic cells (DDC. However, the main obstacle for transcutaneous immunization (TCI is the effective delivery of the vaccine through the stratum corneum (SC barrier to the APC in the deeper skin layers. This study therefore utilized microneedles (MN and a lipid-based colloidal delivery system (cubosomes as a synergistic approach for the delivery of vaccines to APC in the skin. The process of vaccine uptake and recruitment by specific types of skin APC was investigated in real-time over 4 hours in B6.Cg-Tg (Itgax-EYFP 1 Mnz/J mice by two-photon microscopy. Incorporation of the vaccine into a particulate delivery system and the use of MN preferentially increased vaccine antigen uptake by a highly motile subpopulation of skin APC known as CD207⁺ DC. No uptake of antigen or any response to immunisation by LC could be detected.

  14. Non-neuronal Cells in ALS: Role of Glial, Immune cells and Blood-CNS Barriers.

    Science.gov (United States)

    Puentes, Fabiola; Malaspina, Andrea; van Noort, Johannes M; Amor, Sandra

    2016-03-01

    Neurological dysfunction and motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is strongly associated with neuroinflammation reflected by activated microglia and astrocytes in the CNS. In ALS endogenous triggers in the CNS such as aggregated protein and misfolded proteins activate a pathogenic response by innate immune cells. However, there is also strong evidence for a neuroprotective immune response in ALS. Emerging evidence also reveals changes in the peripheral adaptive immune responses as well as alterations in the blood brain barrier that may aid traffic of lymphocytes and antibodies into the CNS. Understanding the triggers of neuroinflammation is key to controlling neuronal loss. Here, we review the current knowledge regarding the roles of non-neuronal cells as well as the innate and adaptive immune responses in ALS. Existing ALS animal models, in particular genetic rodent models, are very useful to study the underlying pathogenic mechanisms of motor neuron degeneration. We also discuss the approaches used to target the pathogenic immune responses and boost the neuroprotective immune pathways as novel immunotherapies for ALS.

  15. Cell-mediated responses of immunized vervet monkeys to defined Leishmania T-cell epitopes.

    OpenAIRE

    Curry, A J; Jardim, A; Olobo, J.O.; Olafson, R W

    1994-01-01

    A population of vervet monkeys was immunized with killed parasites and infected with Leishmania major promastigotes either by needle or by infected-fly bite. The responses of recovered monkeys to mitogens, killed parasites, and molecularly defined T-cell epitopes were then compared with those of control animals. Peripheral blood mononuclear cells (PBMC) from both naive and recovered animals proliferated strongly in response to both B- and T-cell mitogens, although the responses of the recover...

  16. Innate Valpha14(+) natural killer T cells mature dendritic cells, leading to strong adaptive immunity.

    Science.gov (United States)

    Fujii, Shin-Ichiro; Shimizu, Kanako; Hemmi, Hiroaki; Steinman, Ralph M

    2007-12-01

    The observation that the glycolipid alpha-galactosylceramide (alpha-GalCer) is a potent stimulator of natural killer T (NKT) cells has provided an important means for investigating NKT cell biology. alpha-GalCer is presented on CD1d to the invariant NKT receptor, leading to interleukin-12 (IL-12) production by dendritic cells (DCs) and to NK cell activation. We review our research on the tumor-protective properties of alpha-GalCer, particularly the major role played by DCs. We compared administration of alpha-GalCer on mature DCs with soluble glycolipid and found that DCs induced more prolonged interferon-gamma (IFN-gamma) production by NKT cells and better protection against B16 melanoma. Human alpha-GalCer-loaded DCs also expanded NKT cell numbers in cancer patients. alpha-GalCer-activated NKT cells were then found to induce DC maturation in vivo. The maturing DCs produced IL-12, upregulated co-stimulatory molecules, and induced adaptive immunity to captured cellular antigens, including prolonged, combined CD4(+)/CD8(+) T-cell immunity to dying tumor cells. Surprisingly, co-stimulator-poor tumor cells, if directly loaded with alpha-GalCer ('tumor/Gal') and injected intravenously, also induced strong NKT- and NK-cell responses. The latter killed the tumor/Gal, which were subsequently cross presented by CD1d on DCs to elicit DC maturation and prolonged adaptive T-cell immunity, which lasted 6-12 months. These findings help explain tumor protection via alpha-GalCer and urge development of the DC-NKT axis to provide innate and adaptive immunity to human cancers.

  17. Therapeutic immunization with HIV-1 Tat reduces immune activation and loss of regulatory T-cells and improves immune function in subjects on HAART.

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    Barbara Ensoli

    Full Text Available UNLABELLED: Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4(+ T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002. Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002, served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4(+ and CD8(+ cellular activation (CD38 and HLA-DR together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4(+ T cells and B cells with reduction of CD8(+ T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4(+ and CD8(+ T cells were accompanied by increases of CD4(+ and CD8(+ T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes

  18. Cancer immunotherapy: nanodelivery approaches for immune cell targeting and tracking

    Science.gov (United States)

    Conniot, João; Silva, Joana; Fernandes, Joana; Silva, Liana; Gaspar, Rogério; Brocchini, Steve; Florindo, Helena; Barata, Teresa

    2014-11-01

    Cancer is one of the most common diseases afflicting people globally. New therapeutic approaches are needed due to the complexity of cancer as a disease. Many current treatments are very toxic and have modest efficacy at best. Increased understanding of tumor biology and immunology has allowed the development of specific immunotherapies with minimal toxicity. It is important to highlight the performance of monoclonal antibodies, immune adjuvants, vaccines and cell-based treatments. Although these approaches have shown varying degrees of clinical efficacy, they illustrate the potential to develop new strategies. Targeted immunotherapy is being explored to overcome the heterogeneity of malignant cells and the immune suppression induced by both the tumor and its microenvironment. Nanodelivery strategies seek to minimize systemic exposure to target therapy to malignant tissue and cells. Intracellular penetration has been examined through the use of functionalized particulates. These nano-particulate associated medicines are being developed for use in imaging, diagnostics and cancer targeting. Although nano-particulates are inherently complex medicines, the ability to confer, at least in principle, different types of functionality allows for the plausible consideration these nanodelivery strategies can be exploited for use as combination medicines. The development of targeted nanodelivery systems in which therapeutic and imaging agents are merged into a single platform is an attractive strategy. Currently, several nanoplatform-based formulations, such as polymeric nanoparticles, micelles, liposomes and dendrimers are in preclinical and clinical stages of development. Herein, nanodelivery strategies presently investigated for cancer immunotherapy, cancer targeting mechanisms and nanocarrier functionalization methods will be described. We also intend to discuss the emerging nano-based approaches suitable to be used as imaging techniques and as cancer treatment options.

  19. Cell-based Fluorescence Complementation Reveals a Role for HIV-1 Nef Protein Dimerization in AP-2 Adaptor Recruitment and CD4 Co-receptor Down-regulation.

    Science.gov (United States)

    Shu, Sherry T; Emert-Sedlak, Lori A; Smithgall, Thomas E

    2017-02-17

    The HIV-1 Nef accessory factor enhances viral infectivity, immune evasion, and AIDS progression. Nef triggers rapid down-regulation of CD4 via the endocytic adaptor protein 2 (AP-2) complex, a process linked to enhanced viral infectivity and immune escape. Here, we describe a bimolecular fluorescence complementation (BiFC) assay to visualize the interaction of Nef with AP-2 and CD4 in living cells. Interacting protein pairs were fused to complementary non-fluorescent fragments of YFP and co-expressed in 293T cells. Nef interactions with both CD4 and AP-2 resulted in complementation of YFP and a bright fluorescent signal by confocal microcopy that localized to the cell periphery. Co-expression of the AP-2 α subunit enhanced the Nef·AP-2 σ2 subunit BiFC signal and vice versa, suggesting that the AP-2 α-σ2 hemicomplex interacts cooperatively with Nef. Mutagenesis of Nef amino acids Arg-134, Glu-174, and Asp-175, which stabilize Nef for AP-2 α-σ2 binding in a recent co-crystal structure, substantially reduced AP-2 interaction without affecting CD4 binding. A dimerization-defective mutant of Nef failed to interact with either CD4 or AP-2 in the BiFC assay, indicating that Nef quaternary structure is required for CD4 and AP-2 recruitment as well as CD4 down-regulation. A small molecule previously shown to bind the Nef dimerization interface also reduced Nef interactions with AP-2 and CD4 and restored CD4 expression to the surface of HIV-infected cells. Our findings provide a mechanistic explanation for previous observations that dimerization-defective Nef mutants fail to down-regulate CD4 and validate the Nef dimerization interface as a target site for antiretroviral drug development. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. Homeostatic migration and distribution of innate immune cells in primary and secondary lymphoid organs with ageing.

    Science.gov (United States)

    Nikolich-Žugich, J; Davies, J S

    2017-03-01

    Ageing of the innate and adaptive immune system, collectively termed immune senescence, is a complex process. One method to understand the components of ageing involves dissociating the effects of ageing on the cells of the immune system, on the microenvironment in lymphoid organs and tissues where immune cells reside and on the circulating factors that interact with both immune cells and their microenvironment. Heterochronic parabiosis, a surgical union of two organisms of disparate ages, is ideal for this type of study, as it has the power to dissociate the age of the cell and the age of the microenvironment into which the cell resides or is migrating. So far, however, it has been used sparingly to study immune ageing. Here we review the limited literature on homeostatic innate immune cell trafficking in ageing in the absence of chronic inflammation. We also review our own recent data on trafficking of innate immune subsets between primary and secondary lymphoid organs in heterochronic parabiosis. We found no systemic bias in retention or acceptance of neutrophils, macrophages, dendritic cells or natural killer cells with ageing in primary and secondary lymphoid organs. We conclude that these four innate immune cell types migrate to and populate lymphoid organs (peripheral lymph nodes, spleen and bone marrow), regardless of their own age and of the age of lymphoid organs. © 2017 British Society for Immunology.

  1. Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition.

    Science.gov (United States)

    Reitz, M U; Gifford, M L; Schäfer, P

    2015-04-01

    Biotic stress and diseases caused by pathogen attack pose threats in crop production and significantly reduce crop yields. Enhancing immunity against pathogens is therefore of outstanding importance in crop breeding. However, this must be balanced, as immune activation inhibits plant growth. This immunity-coupled growth trade-off does not support resistance but is postulated to reflect the reallocation of resources to drive immunity. There is, however, increasing evidence that growth-immunity trade-offs are based on the reconfiguration of hormone pathways, shared by growth and immunity signalling. Studies in roots revealed the role of hormones in orchestrating growth across different cell types, with some hormones showing a defined cell type-specific activity. This is apparently highly relevant for the regulation of the cell cycle machinery and might be part of the growth-immunity cross-talk. Since plants are constantly exposed to Immuno-activating microbes under agricultural conditions, the transition from a growth to an immunity operating mode can significantly reduce crop yield and can conflict our efforts to generate next-generation crops with improved yield under climate change conditions. By focusing on roots, we outline the current knowledge of hormone signalling on the cell cycle machinery to explain growth trade-offs induced by immunity. By referring to abiotic stress studies, we further introduce how root cell type-specific hormone activities might contribute to growth under immunity and discuss the feasibility of uncoupling the growth-immunity cross-talk.

  2. A systems model for immune cell interactions unravels the mechanism of inflammation in human skin.

    Directory of Open Access Journals (Sweden)

    Najl V Valeyev

    Full Text Available Inflammation is characterized by altered cytokine levels produced by cell populations in a highly interdependent manner. To elucidate the mechanism of an inflammatory reaction, we have developed a mathematical model for immune cell interactions via the specific, dose-dependent cytokine production rates of cell populations. The model describes the criteria required for normal and pathological immune system responses and suggests that alterations in the cytokine production rates can lead to various stable levels which manifest themselves in different disease phenotypes. The model predicts that pairs of interacting immune cell populations can maintain homeostatic and elevated extracellular cytokine concentration levels, enabling them to operate as an immune system switch. The concept described here is developed in the context of psoriasis, an immune-mediated disease, but it can also offer mechanistic insights into other inflammatory pathologies as it explains how interactions between immune cell populations can lead to disease phenotypes.

  3. Immune receptors involved in Streptococcus suis recognition by dendritic cells.

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    Marie-Pier Lecours

    Full Text Available Streptococcus suis is an important swine pathogen and an emerging zoonotic agent of septicemia and meningitis. Knowledge on host immune responses towards S. suis, and strategies used by this pathogen for subversion of these responses is scarce. The objective of this study was to identify the immune receptors involved in S. suis recognition by dendritic cells (DCs. Production of cytokines and expression of co-stimulatory molecules by DCs were shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize S. suis and become activated mostly through Toll-like receptor (TLR signaling. Supporting this fact, TLR2(-/- DCs were severely impaired in the release of several cytokines and the surface expression of CD86 and MHC-II. The release of IL-12p70 and CXC10, and the expression of CD40 were found to depend on signaling by both TLR2 and TLR9. The release of IL-23 and CXCL1 were partially dependent on NOD2. Finally, despite the fact that MyD88 signaling was crucial for DC activation and maturation, MyD88-dependent pathways were not implicated in S. suis internalization by DCs. This first study on receptors involved in DC activation by S. suis suggests a major involvement of MyD88 signaling pathways, mainly (but not exclusively through TLR2. A multimodal recognition involving a combination of different receptors seems essential for DC effective response to S. suis.

  4. Effects of chrysotherapy on cell mediated immune response.

    Science.gov (United States)

    Lorber, A; Jackson, W H; Simon, T M

    1982-01-01

    Auranofin (AF) differs significantly from gold sodium thiomalate (GSTM) in formulation, i.e., aurous gold is stabilized by dual sulfur and phosphorus ligands, hydrophobic rather than hydrophilic characteristics, and lack of ionic charge. These attributes facilitate: oral absorption of AF, plasma membrane penetration, increase in intracellular lymphocyte gold concentration; and perhaps thereby influence lymphocyte function. AF treated subjects recorded prompt and sharp declines in mitogen-induced lymphoproliferative response (LMR) greater than 80%; suppressed response to skin testing with dinitrochlorobenezene (DNCB) in 11 of 14 subjects; and blebbing of lymphocyte membranes by scanning electron microscopy. In contrast, lymphocytes from a matched group of GSTM treated subjects recorded later onset and less suppression of LMR; normal response to DNCB skin testing; and did not manifest membrane blebbing. Accordingly, the therapeutic action of AF on immune response was observed in the 16 subjects receiving 6 mg/d of an average of 45 weeks to effect primarily cell mediated rather than humoral immune response when compared with a matched group of GSTM treated patients.

  5. Modeling putative therapeutic implications of exosome exchange between tumor and immune cells.

    Science.gov (United States)

    Lu, Mingyang; Huang, Bin; Hanash, Samir M; Onuchic, José N; Ben-Jacob, Eshel

    2014-10-07

    Development of effective strategies to mobilize the immune system as a therapeutic modality in cancer necessitates a better understanding of the contribution of the tumor microenvironment to the complex interplay between cancer cells and the immune response. Recently, effort has been directed at unraveling the functional role of exosomes and their cargo of messengers in this interplay. Exosomes are small vesicles (30-200 nm) that mediate local and long-range communication through the horizontal transfer of information, such as combinations of proteins, mRNAs and microRNAs. Here, we develop a tractable theoretical framework to study the putative role of exosome-mediated cell-cell communication in the cancer-immunity interplay. We reduce the complex interplay into a generic model whose three components are cancer cells, dendritic cells (consisting of precursor, immature, and mature types), and killer cells (consisting of cytotoxic T cells, helper T cells, effector B cells, and natural killer cells). The framework also incorporates the effects of exosome exchange on enhancement/reduction of cell maturation, proliferation, apoptosis, immune recognition, and activation/inhibition. We reveal tristability-possible existence of three cancer states: a low cancer load with intermediate immune level state, an intermediate cancer load with high immune level state, and a high cancer load with low immune-level state, and establish the corresponding effective landscape for the cancer-immunity network. We illustrate how the framework can contribute to the design and assessments of combination therapies.

  6. Bone stroma-derived cells change coregulators recruitment to androgen receptor and decrease cell proliferation in androgen-sensitive and castration-resistant prostate cancer cells

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