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Sample records for selective t-cell ablation

  1. Selective T-cell Ablation with Bismuth-213 Labeled Anti-TCR Alpha Beta as Nonmyeloablative Conditioning for Allogeneic Canine Marrow Transplantion

    International Nuclear Information System (INIS)

    Bethge, W. A.; Wilbur, D. Scott; Storb, R.; Hamlin, Donald K.; Santos, E. B.; Brechbiel, M. W.; Fisher, Darrell R.; Sandmaier, B. M.

    2003-01-01

    Two major immunological barriers, the host versus graft (HVG) and the graft versus host (GVH) reaction, must be overcome for successful allogeneic hematopoietic stem cell transplantation. T-cells are involved in these barriers in the major histocompatibility complex-identical settings. We hypothesized that selective ablation of T-cells using radioimmunotherapy, together with postgrafting immunosuppression, would ensure stable allogeneic engraftment. We developed a canine model of nonmyeloablative marrow transplantation in which host immune reactions are impaired by a single dose of 2 Gy total body irradiation (TBI), and where both GVH and residual HVG reactions are controlled by postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporine (CSP). We substituted the alpha-emitter bismuth-213 linked to a monoclonal antibody against TCR(alpha,beta)using the metal-binding chelate CHX-A-DTPA, for 2 Gy TBI. Biodistribution studies using a gamma-emitting indium-111-labeled anti-TCR mAb showed uptake primarily in blood, marrow, lymph nodes, spleen and liver. In a dosimetry study, 4 dogs were treated with 0.13-0.46 mg/kg TCR mAb labeled with 3.7-5.6 mCi/kg (137-207 MBq/kg) Bi-213. The treatment was administered in 6 injections on days -3 and -2 followed by transplantion of dog leukocyte antigen-identical marrow on day 0 and postgrafting immunosuppression with MMF and CSP. Therapy was well tolerated except for elevations of transaminases, which were transient in all but one dog. No other organ toxicities or signs of graft-versus-host-disease were noted. The dogs had prompt allogeneic hematopoietic engraftment and achieved stable mixed donor-host hematopoietic chimerism with donor contributions ranging from 5-55 % with >30 weeks follow up

  2. Selective T-cell Ablation with Bismuth-213 Labeled Anti-TCR Alpha Beta as Nonmyeloablative Conditionaing for Allogeneic Canine Marrow Transplantion

    Energy Technology Data Exchange (ETDEWEB)

    Bethge, W. A.; Wilbur, D. Scott; Storb, R.; Hamlin, Donald K.; Santos, E. B.; Brechbiel, M. W.; Fisher, Darrell R.; Sandmaier, B. M.

    2003-06-15

    Two major immunological barriers, the host versus graft (HVG) and the graft versus host (GVH) reaction, must be overcome for successful allogeneic hematopoietic stem cell transplantation. T-cells are involved in these barriers in the major histocompatibility complex-identical settings. We hypothesized that selective ablation of T-cells using radioimmunotherapy, together with postgrafting immunosuppression, would ensure stable allogeneic engraftment. We developed a canine model of nonmyeloablative marrow transplantation in which host immune reactions are impaired by a single dose of 2 Gy total body irradiation (TBI), and where both GVH and residual HVG reactions are controlled by postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporine (CSP). We substituted the alpha-emitter bismuth-213 linked to a monoclonal antibody against TCR(alpha,beta)using the metal-binding chelate CHX-A”-DTPA, for 2 Gy TBI. Biodistribution studies using a gamma-emitting indium-111-labeled anti-TCR mAb showed uptake primarily in blood, marrow, lymph nodes, spleen and liver. In a dosimetry study, 4 dogs were treated with 0.13-0.46 mg/kg TCR mAb labeled with 3.7-5.6 mCi/kg (137-207 MBq/kg) Bi-213. The treatment was administered in 6 injections on days -3 and -2 followed by transplantion of dog leukocyte antigen-identical marrow on day 0 and postgrafting immunosuppression with MMF and CSP. Therapy was well tolerated except for elevations of transaminases, which were transient in all but one dog. No other organ toxicities or signs of graft-versus-host-disease were noted. The dogs had prompt allogeneic hematopoietic engraftment and achieved stable mixed donor-host hematopoietic chimerism with donor contributions ranging from 5-55 % with >30 weeks follow up.

  3. Conditional ablation of CD205+ conventional dendritic cells impacts the regulation of T-cell immunity and homeostasis in vivo.

    Science.gov (United States)

    Fukaya, Tomohiro; Murakami, Ryuichi; Takagi, Hideaki; Sato, Kaori; Sato, Yumiko; Otsuka, Haruna; Ohno, Michiko; Hijikata, Atsushi; Ohara, Osamu; Hikida, Masaki; Malissen, Bernard; Sato, Katsuaki

    2012-07-10

    Dendritic cells (DCs) are composed of multiple subsets that play a dual role in inducing immunity and tolerance. However, it is unclear how CD205(+) conventional DCs (cDCs) control immune responses in vivo. Here we generated knock-in mice with the selective conditional ablation of CD205(+) cDCs. CD205(+) cDCs contributed to antigen-specific priming of CD4(+) T cells under steady-state conditions, whereas they were dispensable for antigen-specific CD4(+) T-cell responses under inflammatory conditions. In contrast, CD205(+) cDCs were required for antigen-specific priming of CD8(+) T cells to generate cytotoxic T lymphocytes (CTLs) mediated through cross-presentation. Although CD205(+) cDCs were involved in the thymic generation of CD4(+) regulatory T cells (Tregs), they maintained the homeostasis of CD4(+) Tregs and CD4(+) effector T cells in peripheral and mucosal tissues. On the other hand, CD205(+) cDCs were involved in the inflammation triggered by Toll-like receptor ligand as well as bacterial and viral infections. Upon microbial infections, CD205(+) cDCs contributed to the cross-priming of CD8(+) T cells for generating antimicrobial CTLs to efficiently eliminate pathogens, whereas they suppressed antimicrobial CD4(+) T-cell responses. Thus, these findings reveal a critical role for CD205(+) cDCs in the regulation of T-cell immunity and homeostasis in vivo.

  4. Selective Expansion of Memory CD4+ T cells By Mitogenic Human CD28 Generates Inflammatory Cytokines and Regulatory T cells

    Science.gov (United States)

    Singh, Manisha; Basu, Sreemanti; Camell, Christina; Couturier, Jacob; Nudelman, Rodolfo J.; Medina, Miguel A.; Rodgers, John R.; Lewis, Dorothy E.

    2009-01-01

    Co-stimulatory signals are important for development of effector and regulatory T cells. In this case, CD28 signaling is usually considered inert in the absence of signaling through the TCR. By contrast, mitogenic rat CD28 mAbs reportedly expand regulatory T cells without TCR stimulation. We found that a commercially available human CD28 mAb (ANC28) stimulated PBMCs without TCR co-ligation or cross-linking; ANC28 selectively expanded CD4+CD25+FoxP3−(T effector) and CD4+CD25+FoxP3+ (Treg) cells. ANC28 stimulated the CD45RO+ CD4+ (memory) population whereas CD45RA+CD4+ (naïve) cells did not respond. ANC28 also induced inflammatory cytokines. Treg induced by ANC28 retain the Treg phenotype longer than did co-stimulated Treg. Treg induced by ANC28 suppressed CD25− T cells through a contact-dependent mechanism. Purity influenced the response of CD4+CD25+ cells because bead-purified CD4+CD25+ cells (85–90% pure) responded strongly to ANC28, whereas 98% pure FACS-sorted CD4+CD25 bright (T-reg) did not respond. Purified CD4+CD25int cells responded similarly to the bead-purified CD4+CD25+ cells. Thus, pre-activated CD4+ T cells (CD25int) respond to ANC28 rather than Treg (CD25bright). The ability of ANC28 to expand both effectors producing inflammatory cytokines as well as suppressive regulatory T cells might be useful for ex vivo expansion of therapeutic T cells. PMID:18446791

  5. Diethylstilbestrol alters positive and negative selection of T cells in the thymus and modulates T-cell repertoire in the periphery

    International Nuclear Information System (INIS)

    Brown, Nicole; Nagarkatti, Mitzi; Nagarkatti, Prakash S.

    2006-01-01

    Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effects of DES on T-cell differentiation in the thymus using the HY-TCR transgenic (Tg) mouse model in which the female mice exhibit positive selection of T cells bearing the Tg TCR, while the male mice show negative selection of such T cells. In female HY-TCR-Tg mice, exposure to DES showed more pronounced decrease in thymic cellularity when compared to male mice. Additionally, female mice also showed a significant decrease in the proportion of double-positive (DP) T cells in the thymus and HY-TCR-specific CD8 + T cells in the periphery. Male mice exhibiting negative selection also showed decreased thymic cellularity following DES exposure. Moreover, the male mice showed increased proportion of double-negative (DN) T cells in the thymus and decreased proportion of CD8 + T cells. The density of expression of HY-TCR on CD8 + cells was increased following DES exposure in both females and males. Finally, the proliferative response of thymocytes to mitogens and peripheral lymph node T cells to male H-Y antigen was significantly altered in female and male mice following DES treatment. Taken together, these data suggest that DES alters T-cell differentiation in the thymus by interfering with positive and negative selection processes, which in turn modulates the T-cell repertoire in the periphery

  6. Selective T-cell depletion targeting CD45RA reduces viremia and enhances early T-cell recovery compared with CD3-targeted T-cell depletion.

    Science.gov (United States)

    Triplett, Brandon M; Muller, Brad; Kang, Guolian; Li, Ying; Cross, Shane J; Moen, Joseph; Cunningham, Lea; Janssen, William; Mamcarz, Ewelina; Shook, David R; Srinivasan, Ashok; Choi, John; Hayden, Randall T; Leung, Wing

    2018-02-01

    T-cell depletion (TCD) effectively reduces severe graft-versus-host disease in recipients of HLA-mismatched allografts. However, TCD is associated with delayed immune recovery and increased infections. We hypothesized that specific depletion of CD45RA+ naive T cells, rather than broad depletion of CD3+ T cells, can preserve memory-immunity in the allografts and confer protection against important viral infections in the early post-transplant period. Sixty-seven patients who received TCD haploidentical donor transplantation for hematologic malignancy on 3 consecutive trials were analyzed. Patients receiving CD45RA-depleted donor grafts had 2000-fold more donor T cells infused, significantly higher T-cell counts at Day +30 post transplant (550/μL vs 10/μL; P depleted grafts were more likely to experience adenovirus viremia (27% vs 4%, P = .02). CD45RA-depletion provided a large number of donor memory T cells to the recipients and was associated with enhanced early T-cell recovery and protection against viremia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Diethylstilbestrol alters positive and negative selection of T cells in the thymus and modulates T-cell repertoire in the periphery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Nicole [Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298 (United States); Nagarkatti, Mitzi [Department of Microbiology and Immunology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298 (United States); Nagarkatti, Prakash S [Department of Pharmacology and Toxicology, PO Box 980613, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0613 (United States)

    2006-04-15

    Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effects of DES on T-cell differentiation in the thymus using the HY-TCR transgenic (Tg) mouse model in which the female mice exhibit positive selection of T cells bearing the Tg TCR, while the male mice show negative selection of such T cells. In female HY-TCR-Tg mice, exposure to DES showed more pronounced decrease in thymic cellularity when compared to male mice. Additionally, female mice also showed a significant decrease in the proportion of double-positive (DP) T cells in the thymus and HY-TCR-specific CD8{sup +} T cells in the periphery. Male mice exhibiting negative selection also showed decreased thymic cellularity following DES exposure. Moreover, the male mice showed increased proportion of double-negative (DN) T cells in the thymus and decreased proportion of CD8{sup +} T cells. The density of expression of HY-TCR on CD8{sup +} cells was increased following DES exposure in both females and males. Finally, the proliferative response of thymocytes to mitogens and peripheral lymph node T cells to male H-Y antigen was significantly altered in female and male mice following DES treatment. Taken together, these data suggest that DES alters T-cell differentiation in the thymus by interfering with positive and negative selection processes, which in turn modulates the T-cell repertoire in the periphery.

  8. How nonuniform contact profiles of T cell receptors modulate thymic selection outcomes

    Science.gov (United States)

    Chen, Hanrong; Chakraborty, Arup K.; Kardar, Mehran

    2018-03-01

    T cell receptors (TCRs) bind foreign or self-peptides attached to major histocompatibility complex (MHC) molecules, and the strength of this interaction determines T cell activation. Optimizing the ability of T cells to recognize a diversity of foreign peptides yet be tolerant of self-peptides is crucial for the adaptive immune system to properly function. This is achieved by selection of T cells in the thymus, where immature T cells expressing unique, stochastically generated TCRs interact with a large number of self-peptide-MHC; if a TCR does not bind strongly enough to any self-peptide-MHC, or too strongly with at least one self-peptide-MHC, the T cell dies. Past theoretical work cast thymic selection as an extreme value problem and characterized the statistical enrichment or depletion of amino acids in the postselection TCR repertoire, showing how T cells are selected to be able to specifically recognize peptides derived from diverse pathogens yet have limited self-reactivity. Here, we investigate how the diversity of the postselection TCR repertoire is modified when TCRs make nonuniform contacts with peptide-MHC. Specifically, we were motivated by recent experiments showing that amino acids at certain positions of a TCR sequence have large effects on thymic selection outcomes, and crystal structure data that reveal a nonuniform contact profile between a TCR and its peptide-MHC ligand. Using a representative TCR contact profile as an illustration, we show via simulations that the statistical enrichment or depletion of amino acids now varies by position according to the contact profile, and, importantly, it depends on the implementation of nonuniform contacts during thymic selection. We explain these nontrivial results analytically. Our study has implications for understanding the selection forces that shape the functionality of the postselection TCR repertoire.

  9. Notch3 is dispensable for thymocyte β-selection and Notch1-induced T cell leukemogenesis.

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    Sara Suliman

    Full Text Available Notch1 (N1 signaling induced by intrathymic Delta-like (DL ligands is required for T cell lineage commitment as well as self-renewal during "β-selection" of TCRβ⁺CD4⁻CD8⁻ double negative 3 (DN3 T cell progenitors. However, over-expression of the N1 intracellular domain (ICN1 renders N1 activation ligand-independent and drives leukemic transformation during β-selection. DN3 progenitors also express Notch3 (N3 mRNA, and over-expression of ligand-independent mutant N3 (ICN3 influences β-selection and drives T cell leukemogenesis. However, the importance of ligand-activated N3 in promoting β-selection and ICN1-induced T cell leukemogenesis has not been examined. To address these questions we generated mice lacking functional N3. We confirmed that DN3 progenitors express N3 protein using a N3-specific antibody. Surprisingly however, N3-deficient DN3 thymocytes were not defective in generating DP thymocytes under steady state conditions or in more stringent competition assays. To determine if N3 co-operates with N1 to regulate β-selection, we generated N1;N3 compound mutants. However, N3 deficiency did not exacerbate the competitive defect of N1⁺/⁻ DN3 progenitors, demonstrating that N3 does not compensate for limiting N1 during T cell development. Finally, N3 deficiency did not attenuate T cell leukemogenesis induced by conditional expression of ICN1 in DN3 thymocytes. Importantly, we showed that in contrast to N1, N3 has a low binding affinity for DL4, the most abundant intrathymic DL ligand. Thus, despite the profound effects of ectopic ligand-independent N3 activation on T cell development and leukemogenesis, physiologically activated N3 is dispensable for both processes, likely because N3 interacts poorly with intrathymic DL4.

  10. Selective Laser Ablation and Melting, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this project Advratech will develop a new additive manufacturing (AM) process called Selective Laser Ablation and Melting (SLAM). The key innovation in this...

  11. Nonimmune cells equipped with T-cell-receptor-like signaling for cancer cell ablation.

    Science.gov (United States)

    Kojima, Ryosuke; Scheller, Leo; Fussenegger, Martin

    2018-01-01

    The ability to engineer custom cell-contact-sensing output devices into human nonimmune cells would be useful for extending the applicability of cell-based cancer therapies and for avoiding risks associated with engineered immune cells. Here we have developed a new class of synthetic T-cell receptor-like signal-transduction device that functions efficiently in human nonimmune cells and triggers release of output molecules specifically upon sensing contact with a target cell. This device employs an interleukin signaling cascade, whose OFF/ON switching is controlled by biophysical segregation of a transmembrane signal-inhibitory protein from the sensor cell-target cell interface. We further show that designer nonimmune cells equipped with this device driving expression of a membrane-penetrator/prodrug-activating enzyme construct could specifically kill target cells in the presence of the prodrug, indicating its potential usefulness for target-cell-specific, cell-based enzyme-prodrug cancer therapy. Our study also contributes to the advancement of synthetic biology by extending available design principles to transmit extracellular information to cells.

  12. Relative contribution of "determinant selection" and "holes in the T-cell repertoire" to T-cell responses

    DEFF Research Database (Denmark)

    Schaeffer, E B; Sette, A; Johnson, D L

    1989-01-01

    -cell responses. Ia binding and Ia-restricted T-cell immunogenicity could be determined for a total of 54 peptide-MHC combinations. Only 30% of the 54 instances examined involved detectable Ia binding, but they represented almost all (12 of 13) of the immune responses found. However, binding to Ia......Using BALB/c and CBA/J mice, the I-region associated (Ia) binding capacity and T-cell immunogenicity of a panel of 14 overlapping peptides that span the entire sequence of the protein staphylococcal nuclease (Nase) was examined to evaluate major histocompatibility gene complex (MHC) control of T...... was not sufficient to ensure T-cell immunogenicity, since only 70% of the binding events were productive--i.e., were associated with an immune response. Thus, Ia molecules have the expected characteristics of a highly permissive capacity for antigen interaction that allows them to function as restriction elements...

  13. Innate-like CD4 T cells selected by thymocytes suppress adaptive immune responses against bacterial infections

    OpenAIRE

    Qiao, Yu; Gray, Brian M.; Sofi, Mohammed H.; Bauler, Laura D.; Eaton, Kathryn A.; O'Riordan, Mary X. D.; Chang, Cheong-Hee

    2011-01-01

    We have reported a new innate-like CD4 T cell population that expresses cell surface makers of effector/memory cells and produce Th1 and Th2 cytokines immediately upon activation. Unlike conventional CD4 T cells that are selected by thymic epithelial cells, these CD4 T cells, named T-CD4 T cells, are selected by MHC class II expressing thymocytes. Previously, we showed that the presence of T-CD4 T cells protected mice from airway inflammation suggesting an immune regulatory role of T-CD4 T ce...

  14. Conflicting selective forces affect T cell receptor contacts in an immunodominant human immunodeficiency virus epitope

    DEFF Research Database (Denmark)

    Iversen, Astrid K N; Stewart-Jones, Guillaume; Learn, Gerald H

    2006-01-01

    two principal, diametrically opposed evolutionary pathways that exclusively affect T cell-receptor contact residues. One pathway was characterized by acquisition of CTL escape mutations and the other by selection for wild-type amino acids. The pattern of CTL responses to epitope variants shaped which...

  15. Adenovirus-specific T-cell Subsets in Human Peripheral Blood and After IFN-γ Immunomagnetic Selection.

    Science.gov (United States)

    Qian, Chongsheng; Wang, Yingying; Cai, Huili; Laroye, Caroline; De Carvalho Bittencourt, Marcelo; Clement, Laurence; Stoltz, Jean-François; Decot, Véronique; Reppel, Loïc; Bensoussan, Danièle

    2016-01-01

    Adoptive antiviral cellular immunotherapy by infusion of virus-specific T cells (VSTs) is becoming an alternative treatment for viral infection after hematopoietic stem cell transplantation. The T memory stem cell (TSCM) subset was recently described as exhibiting self-renewal and multipotency properties which are required for sustained efficacy in vivo. We wondered if such a crucial subset for immunotherapy was present in VSTs. We identified, by flow cytometry, TSCM in adenovirus (ADV)-specific interferon (IFN)-γ+ T cells before and after IFN-γ-based immunomagnetic selection, and analyzed the distribution of the main T-cell subsets in VSTs: naive T cells (TN), TSCM, T central memory cells (TCM), T effector memory cell (TEM), and effector T cells (TEFF). In this study all of the different T-cell subsets were observed in the blood sample from healthy donor ADV-VSTs, both before and after IFN-γ-based immunomagnetic selection. As the IFN-γ-based immunomagnetic selection system sorts mainly the most differentiated T-cell subsets, we observed that TEM was always the major T-cell subset of ADV-specific T cells after immunomagnetic isolation and especially after expansion in vitro. Comparing T-cell subpopulation profiles before and after in vitro expansion, we observed that in vitro cell culture with interleukin-2 resulted in a significant expansion of TN-like, TCM, TEM, and TEFF subsets in CD4IFN-γ T cells and of TCM and TEM subsets only in CD8IFN-γ T cells. We demonstrated the presence of all T-cell subsets in IFN-γ VSTs including the TSCM subpopulation, although this was weakly selected by the IFN-γ-based immunomagnetic selection system.

  16. Group 3 innate lymphoid cells mediate intestinal selection of commensal bacteria-specific CD4+ T cells

    Science.gov (United States)

    Hepworth, Matthew R.; Fung, Thomas C.; Masur, Samuel H.; Kelsen, Judith R.; McConnell, Fiona M.; Dubrot, Juan; Withers, David R.; Hugues, Stephanie; Farrar, Michael A.; Reith, Walter; Eberl, Gerard; Baldassano, Robert N.; Laufer, Terri M.; Elson, Charles O.; Sonnenberg, Gregory F.

    2015-01-01

    Inflammatory CD4+ T cell responses to self or commensal bacteria underlie the pathogenesis of autoimmunity and inflammatory bowel disease (IBD), respectively. While selection of self-specific T cells in the thymus limits responses to tissue antigens, the mechanisms that control selection of commensal bacteria-specific T cells remain poorly understood. Here we demonstrate that group 3 innate lymphoid cell (ILC3)-intrinsic expression of major histocompatibility complex class II (MHCII) is regulated similarly to thymic epithelial cells, and that MHCII+ ILC3s directly induce cell death of activated commensal bacteria-specific T cells. Further, MHCII on human colonic ILC3s was reduced in pediatric IBD patients. Collectively, these results define a selection pathway for commensal bacteria-specific CD4+ T cells in the intestine, and suggest that this process is dysregulated in human IBD. PMID:25908663

  17. Oct1 and OCA-B are selectively required for CD4 memory T cell function.

    Science.gov (United States)

    Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N; Snook, Jeremy; Kuchroo, Vijay K; Yosef, Nir; Chan, Raymond C; Regev, Aviv; Williams, Matthew A; Tantin, Dean

    2015-11-16

    Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4(+) memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4(+) T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4(+) T cell memory. © 2015 Shakya et al.

  18. Pregnancy promotes tolerance to future offspring by programming selective dysfunction in long-lived maternal T cells.

    Science.gov (United States)

    Barton, Brendan M; Xu, Rong; Wherry, E John; Porrett, Paige M

    2017-04-01

    Fetal antigen available during pregnancy induces the proliferation of maternal T cells. It is unknown, however, whether these antigen-activated T cells differentiate into long-lived memory T cells that are capable of mediating rapid-recall responses to tissue antigens. To test the hypothesis that pregnancy induces an alternative fate in fetal-specific maternal T cells, we used a murine model to track longitudinally fetal-specific T cells in pregnant and postpartum animals and test the response of these cells when challenged with the same antigen during sequential pregnancy or skin transplantation. Fetal-specific CD8 + T cells were robustly primed during pregnancy but failed to acquire robust effector functions. These primed cells persisted long term in postpartum animals, frequently maintained a programmed death 1 (PD-1) + phenotype, and failed to expand or produce cytokines robustly in response to second pregnancy or skin transplantation. However, whereas there was no impact on second pregnancy as a result of the persistence of fetal-primed memory CD8 + T cells in the mother, skin grafts bearing the same antigen were rejected more rapidly. Altogether, our data suggest that fetal antigen exposure during pregnancy induces the differentiation of long-lived maternal CD8 + T cells with context-dependent, selective effector dysfunction. This programmed effector dysfunction provides temporal and systemic restraint of maternal anti-fetal alloreactivity to promote reproductive fitness efficiently, while preserving potentially protective effector T cell responses. © Society for Leukocyte Biology.

  19. Cre-mediated cell ablation contests mast cell contribution in models of antibody- and T cell-mediated autoimmunity.

    Science.gov (United States)

    Feyerabend, Thorsten B; Weiser, Anne; Tietz, Annette; Stassen, Michael; Harris, Nicola; Kopf, Manfred; Radermacher, Peter; Möller, Peter; Benoist, Christophe; Mathis, Diane; Fehling, Hans Jörg; Rodewald, Hans-Reimer

    2011-11-23

    Immunological functions of mast cells remain poorly understood. Studies in Kit mutant mice suggest key roles for mast cells in certain antibody- and T cell-mediated autoimmune diseases. However, Kit mutations affect multiple cell types of both immune and nonimmune origin. Here, we show that targeted insertion of Cre-recombinase into the mast cell carboxypeptidase A3 locus deleted mast cells in connective and mucosal tissues by a genotoxic Trp53-dependent mechanism. Cre-mediated mast cell eradication (Cre-Master) mice had, with the exception of a lack of mast cells and reduced basophils, a normal immune system. Cre-Master mice were refractory to IgE-mediated anaphylaxis, and this defect was rescued by mast cell reconstitution. This mast cell-deficient strain was fully susceptible to antibody-induced autoimmune arthritis and to experimental autoimmune encephalomyelitis. Differences comparing Kit mutant mast cell deficiency models to selectively mast cell-deficient mice call for a systematic re-evaluation of immunological functions of mast cells beyond allergy. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Rapid selection of escape mutants by the first CD8 T cell responses in acute HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette Tina Marie [Los Alamos National Laboratory

    2008-01-01

    The recent failure of a vaccine that primes T cell responses to control primary HIV-1 infection has raised doubts about the role of CD8+ T cells in early HIV-1 infection. We studied four patients who were identified shortly after HIV-1 infection and before seroconversion. In each patient there was very rapid selection of multiple HIV-1 escape mutants in the transmitted virus by CD8 T cells, including examples of complete fixation of non-synonymous substitutions within 2 weeks. Sequencing by single genome amplification suggested that the high rate of virus replication in acute infection gave a selective advantage to virus molecules that contained simultaneous and gained sequential T cell escape mutations. These observations show that whilst early HIV-1 specific CD8 T cells can act against virus, rapid escape means that these T cell responses are unlikely to benefit the patient and may in part explain why current HIV-1 T cell vaccines may not be protective.

  1. Selective Loss of Early Differentiated, Highly Functional PD1high CD4 T Cells with HIV Progression.

    Directory of Open Access Journals (Sweden)

    Robert M Paris

    Full Text Available The role of PD-1 expression on CD4 T cells during HIV infection is not well understood. Here, we describe the differential expression of PD-1 in CD127high CD4 T cells within the early/intermediate differentiated (EI (CD27highCD45RAlow T cell population among uninfected and HIV-infected subjects, with higher expression associated with decreased viral replication (HIV-1 viral load. A significant loss of circulating PD-1highCTLA-4low CD4 T cells was found specifically in the CD127highCD27highCD45RAlow compartment, while initiation of antiretroviral treatment, particularly in subjects with advanced disease, reversed these dynamics. Increased HIV-1 Gag DNA was also found in PD-1high compared to PD-1low ED CD4 T cells. In line with an increased susceptibility to HIV infection, PD-1 expression in this CD4 T cell subset was associated with increased activation and expression of the HIV co-receptor, CCR5. Rather than exhaustion, this population produced more IFN-g, MIP1-a, IL-4, IL-10, and IL-17a compared to PD-1low EI CD4 T cells. In line with our previous findings, PD-1high EI CD4 T cells were also characterized by a high expression of CCR7, CXCR5 and CCR6, a phenotype associated with increased in vitro B cell help. Our data show that expression of PD-1 on early-differentiated CD4 T cells may represent a population that is highly functional, more susceptible to HIV infection and selectively lost in chronic HIV infection.

  2. Selection and characterization of T-cell variants lacking molecules involved in T-cell activation (T3 T-cell receptor, T44, and T11): analysis of the functional relationship among different pathways of activation

    International Nuclear Information System (INIS)

    Moretta, A.; Poggi, A.; Olive, D.; Bottino, C.; Fortis, C.; Pantaleo, G.; Moretta, L.

    1987-01-01

    A clone of the interleukin 2-producing Jurkat leukemia cell line termed JA3 (surface phenotype, T3 + , Ti + , T44 + , T11 + , T40 + ) has been used to induce and select cell variants lacking surface molecules involved in T-cell activation. Following 200 rad of γ-radiation (1 rad = 0.01 Gy), cells were treated with monoclonal antibodies (mAbs) directed to T3, Ti, T44, or T11 antigen and complement. After growth of the residual cells in culture, negative cells were cloned under limiting conditions. Depending on the specificity of the mAb used for the immunoselection, three groups of variants were obtained. (i) The use of mAbs directed to T3 or Ti resulted in cell variants that expressed the T3 - Ti - T44 + Leu1 + T11 + T40 + 4F2 + HLA class I + surface phenotype. (ii) Immunoselection with anti-T44 mAb resulted in 2 variants that shared the T3 - Ti - T44 - Leu1 - T11 - T40 - 4F2 - HLA class I + phenotype. (iii) Cell treatment with anti-T11 mAb resulted in 15 variants characterized by the lack of T11 antigen expression and of all the other T-cell-specific surface antigens. Therefore, it appears that the different sets of JA3 cell variants, like T cells at discrete stages of intrathymic differentiation, may follow a coordinated expression of surface differentiation antigens. Analysis of the functional responsiveness of the three distinct groups of JA3 cell variants to different stimuli showed that all produced interleukin 2 in response to A23187 calcium ionophore plus phorbol 12-myristate 13-acetate

  3. Elimination of self-reactive T cells in the thymus: a timeline for negative selection.

    Directory of Open Access Journals (Sweden)

    Ivan Lilyanov Dzhagalov

    Full Text Available The elimination of autoreactive T cells occurs via thymocyte apoptosis and removal by thymic phagocytes, but the sequence of events in vivo, and the relationship between thymocyte death and phagocytic clearance, are unknown. Here we address these questions by following a synchronized cohort of thymocytes undergoing negative selection within a three-dimensional thymic tissue environment, from the initial encounter with a negative selecting ligand to thymocyte death and clearance. Encounter with cognate peptide-MHC complexes results in rapid calcium flux and migratory arrest in auto-reactive thymocytes over a broad range of peptide concentrations, followed by a lag period in which gene expression changes occurred, but there was little sign of thymocyte death. Caspase 3 activation and thymocyte loss were first detectable at 2 and 3 hours, respectively, and entry of individual thymocytes into the death program occurred asynchronously over the next 10 hours. Two-photon time-lapse imaging revealed that thymocyte death and phagocytosis occurred simultaneously, often with thymocytes engulfed prior to changes in chromatin and membrane permeability. Our data provide a timeline for negative selection and reveal close coupling between cell death and clearance in the thymus.

  4. Selection of Shared and Neoantigen-Reactive T Cells for Adoptive Cell Therapy Based on CD137 Separation

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    Sivan Seliktar-Ofir

    2017-10-01

    Full Text Available Adoptive cell therapy (ACT of autologous tumor infiltrating lymphocytes (TIL is an effective immunotherapy for patients with solid tumors, yielding objective response rates of around 40% in refractory patients with metastatic melanoma. Most clinical centers utilize bulk, randomly isolated TIL from the tumor tissue for ex vivo expansion and infusion. Only a minor fraction of the administered T cells recognizes tumor antigens, such as shared and mutation-derived neoantigens, and consequently eliminates the tumor. Thus, there are many ongoing effects to identify and select tumor-specific TIL for therapy; however, those approaches are very costly and require months, which is unreasonable for most metastatic patients. CD137 (4-1BB has been identified as a co-stimulatory marker, which is induced upon the specific interaction of T cells with their target cell. Therefore, CD137 can be a useful biomarker and an important tool for the selection of tumor-reactive T cells. Here, we developed and validated a simple and time efficient method for the selection of CD137-expressing T cells for therapy based on magnetic bead separation. CD137 selection was performed with clinical grade compliant reagents, and TIL were expanded in a large-scale manner to meet cell numbers required for the patient setting in a GMP facility. For the first time, the methodology was designed to comply with both clinical needs and limitations, and its feasibility was assessed. CD137-selected TIL demonstrated significantly increased antitumor reactivity and were enriched for T cells recognizing neoantigens as well as shared tumor antigens. CD137-based selection enabled the enrichment of tumor-reactive T cells without the necessity of knowing the epitope specificity or the antigen type. The direct implementation of the CD137 separation method to the cell production of TIL may provide a simple way to improve the clinical efficiency of TIL ACT.

  5. CARbodies: Human Antibodies Against Cell Surface Tumor Antigens Selected From Repertoires Displayed on T Cell Chimeric Antigen Receptors

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    Vanesa Alonso-Camino

    2013-01-01

    Full Text Available A human single-chain variable fragment (scFv antibody library was expressed on the surface of human T cells after transduction with lentiviral vectors (LVs. The repertoire was fused to a first-generation T cell receptor ζ (TCRζ-based chimeric antigen receptor (CAR. We used this library to isolate antibodies termed CARbodies that recognize antigens expressed on the tumor cell surface in a proof-of-principle system. After three rounds of activation-selection there was a clear repertoire restriction, with the emergence dominant clones. The CARbodies were purified from bacterial cultures as soluble and active proteins. Furthermore, to validate its potential application for adoptive cell therapy, human T cells were transduced with a LV encoding a second-generation costimulatory CAR (CARv2 bearing the selected CARbodies. Transduced human primary T cells expressed significant levels of the CARbodies-based CARv2 fusion protein on the cell surface, and importantly could be specifically activated, after stimulation with tumor cells. This approach is a promising tool for the generation of antibodies fully adapted to the display format (CAR and the selection context (cell synapse, which could extend the scope of current adoptive cell therapy strategies with CAR-redirected T cells.

  6. Selected microRNAs define cell fate determination of murine central memory CD8 T cells.

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    Gonzalo Almanza

    2010-06-01

    Full Text Available During an immune response T cells enter memory fate determination, a program that divides them into two main populations: effector memory and central memory T cells. Since in many systems protection appears to be preferentially mediated by T cells of the central memory it is important to understand when and how fate determination takes place. To date, cell intrinsic molecular events that determine their differentiation remains unclear. MicroRNAs are a class of small, evolutionarily conserved RNA molecules that negatively regulate gene expression, causing translational repression and/or messenger RNA degradation. Here, using an in vitro system where activated CD8 T cells driven by IL-2 or IL-15 become either effector memory or central memory cells, we assessed the role of microRNAs in memory T cell fate determination. We found that fate determination to central memory T cells is under the balancing effects of a discrete number of microRNAs including miR-150, miR-155 and the let-7 family. Based on miR-150 a new target, KChIP.1 (K (+ channel interacting protein 1, was uncovered, which is specifically upregulated in developing central memory CD8 T cells. Our studies indicate that cell fate determination such as surface phenotype and self-renewal may be decided at the pre-effector stage on the basis of the balancing effects of a discrete number of microRNAs. These results may have implications for the development of T cell vaccines and T cell-based adoptive therapies.

  7. Engineering human T cells for resistance to methotrexate and mycophenolate mofetil as an in vivo cell selection strategy.

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    Mahesh Jonnalagadda

    Full Text Available Gene transfer and drug selection systems that enforce ongoing transgene expression in vitro and in vivo which are compatible with human pharmaceutical drugs are currently underdeveloped. Here, we report on the utility of incorporating human enzyme muteins that confer resistance to the lymphotoxic/immunosuppressive drugs methotrexate (MTX and mycophenolate mofetil (MMF in a multicistronic lentiviral vector for in vivo T lymphocyte selection. We found that co-expression of human dihydrofolate reductase (DHFR(FS; L22F, F31S and inosine monophosphate dehydrogenase II (IMPDH2(IY; T333I, S351Y conferred T cell resistance to the cytocidal and anti-proliferative effects of these drugs at concentrations that can be achieved clinically (up to 0.1 µM MTX and 1.0 µM MPA. Furthermore, using a immunodeficient mouse model that supports the engraftment of central memory derived human T cells, in vivo selection studies demonstrate that huEGFRt(+DHFR(FS+IMPDH2(IY+ T cells could be enriched following adoptive transfer either by systemic administration of MTX alone (4.4 -fold, MMF alone (2.9-fold, or combined MTX and MMF (4.9-fold. These findings demonstrate the utility of both DHFR(FS/MTX and IMPDH2(IY/MMF for in vivo selection of lentivirally transduced human T cells. Vectors incorporating these muteins in combination with other therapeutic transgenes may facilitate the selective engraftment of therapeutically active cells in recipients.

  8. Engineering human T cells for resistance to methotrexate and mycophenolate mofetil as an in vivo cell selection strategy.

    Science.gov (United States)

    Jonnalagadda, Mahesh; Brown, Christine E; Chang, Wen-Chung; Ostberg, Julie R; Forman, Stephen J; Jensen, Michael C

    2013-01-01

    Gene transfer and drug selection systems that enforce ongoing transgene expression in vitro and in vivo which are compatible with human pharmaceutical drugs are currently underdeveloped. Here, we report on the utility of incorporating human enzyme muteins that confer resistance to the lymphotoxic/immunosuppressive drugs methotrexate (MTX) and mycophenolate mofetil (MMF) in a multicistronic lentiviral vector for in vivo T lymphocyte selection. We found that co-expression of human dihydrofolate reductase (DHFR(FS); L22F, F31S) and inosine monophosphate dehydrogenase II (IMPDH2(IY); T333I, S351Y) conferred T cell resistance to the cytocidal and anti-proliferative effects of these drugs at concentrations that can be achieved clinically (up to 0.1 µM MTX and 1.0 µM MPA). Furthermore, using a immunodeficient mouse model that supports the engraftment of central memory derived human T cells, in vivo selection studies demonstrate that huEGFRt(+)DHFR(FS+)IMPDH2(IY+) T cells could be enriched following adoptive transfer either by systemic administration of MTX alone (4.4 -fold), MMF alone (2.9-fold), or combined MTX and MMF (4.9-fold). These findings demonstrate the utility of both DHFR(FS)/MTX and IMPDH2(IY)/MMF for in vivo selection of lentivirally transduced human T cells. Vectors incorporating these muteins in combination with other therapeutic transgenes may facilitate the selective engraftment of therapeutically active cells in recipients.

  9. Expression of GARP selectively identifies activated human FOXP3+ regulatory T cells.

    Science.gov (United States)

    Wang, Rui; Kozhaya, Lina; Mercer, Frances; Khaitan, Alka; Fujii, Hodaka; Unutmaz, Derya

    2009-08-11

    The molecules that define human regulatory T cells (Tregs) phenotypically and functionally remain to be fully characterized. We recently showed that activated human Tregs express mRNA for a transmembrane protein called glycoprotein A repetitions predominant (GARP, or LRRC32). Here, using a GARP-specific mAb, we demonstrate that expression of GARP on activated Tregs correlates with their suppressive capacity. However, GARP was not induced on T cells activated in the presence of TGFbeta, which expressed high levels of FOXP3 and lacked suppressive function. Ectopic expression of FOXP3 in conventional T cells was also insufficient for induction of GARP expression in most donors. Functionally, silencing GARP in Tregs only moderately attenuated their suppressive activity. CD25+ T cells sorted for high GARP expression displayed more potent suppressive activity compared with CD25+GARP- cells. Remarkably, CD25+GARP- T cells expanded in culture contained 3-5 fold higher IL-17-secreting cells compared with either CD25+GARP+ or CD25-GARP- cells, suggesting that high GARP expression can potentially discriminate Tregs from those that have switched to Th17 lineage. We also determined whether GARP expression correlates with FOXP3-expressing T cells in human immunodeficiency virus (HIV) -infected subjects. A subset of HIV+ individuals with high percentages of FOXP3+ T cells did not show proportionate increase in GARP+ T cells. This finding suggests that higher FOXP3 levels observed in these HIV+ individuals is possibly due to immune activation rather than to an increase in Tregs. Our findings highlight the significance of GARP both in dissecting duality of Treg/Th17 cell differentiation and as a marker to identify bona fide Tregs during diseases with chronic immune activation.

  10. Cis-acting pathways selectively enforce the non-immunogenicity of shed placental antigen for maternal CD8 T cells.

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    Chin-Siean Tay

    Full Text Available Maternal immune tolerance towards the fetus and placenta is thought to be established in part by pathways that attenuate T cell priming to antigens released from the placenta into maternal blood. These pathways remain largely undefined and their existence, at face value, seems incompatible with a mother's need to maintain a functional immune system during pregnancy. A particular conundrum is evident if we consider that maternal antigen presenting cells, activated in order to prime T cells to pathogen-derived antigens, would also have the capacity to prime T cells to co-ingested placental antigens. Here, we address this paradox using a transgenic system in which placental membranes are tagged with a strong surrogate antigen (ovalbumin. We find that although a remarkably large quantity of acellular ovalbumin-containing placental material is released into maternal blood, splenic CD8 T cells in pregnant mice bearing unmanipulated T cell repertoires are not primed to ovalbumin even if the mice are intravenously injected with adjuvants. This failure was largely independent of regulatory T cells, and instead was linked to the intrinsic characteristics of the released material that rendered it selectively non-immunogenic, potentially by sequestering it from CD8α(+ dendritic cells. The release of ovalbumin-containing placental material into maternal blood thus had no discernable impact on CD8 T cell priming to soluble ovalbumin injected intravenously during pregnancy, nor did it induce long-term tolerance to ovalbumin. Together, these results outline a major pathway governing the maternal immune response to the placenta, and suggest how tolerance to placental antigens can be maintained systemically without being detrimental to host defense.

  11. Cis-Acting Pathways Selectively Enforce the Non-Immunogenicity of Shed Placental Antigen for Maternal CD8 T Cells

    Science.gov (United States)

    Tay, Chin-Siean; Tagliani, Elisa; Collins, Mary K.; Erlebacher, Adrian

    2013-01-01

    Maternal immune tolerance towards the fetus and placenta is thought to be established in part by pathways that attenuate T cell priming to antigens released from the placenta into maternal blood. These pathways remain largely undefined and their existence, at face value, seems incompatible with a mother's need to maintain a functional immune system during pregnancy. A particular conundrum is evident if we consider that maternal antigen presenting cells, activated in order to prime T cells to pathogen-derived antigens, would also have the capacity to prime T cells to co-ingested placental antigens. Here, we address this paradox using a transgenic system in which placental membranes are tagged with a strong surrogate antigen (ovalbumin). We find that although a remarkably large quantity of acellular ovalbumin-containing placental material is released into maternal blood, splenic CD8 T cells in pregnant mice bearing unmanipulated T cell repertoires are not primed to ovalbumin even if the mice are intravenously injected with adjuvants. This failure was largely independent of regulatory T cells, and instead was linked to the intrinsic characteristics of the released material that rendered it selectively non-immunogenic, potentially by sequestering it from CD8α+ dendritic cells. The release of ovalbumin-containing placental material into maternal blood thus had no discernable impact on CD8 T cell priming to soluble ovalbumin injected intravenously during pregnancy, nor did it induce long-term tolerance to ovalbumin. Together, these results outline a major pathway governing the maternal immune response to the placenta, and suggest how tolerance to placental antigens can be maintained systemically without being detrimental to host defense. PMID:24391885

  12. Selection of reliable reference genes for quantitative real-time PCR in human T cells and neutrophils

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    Ledderose Carola

    2011-10-01

    Full Text Available Abstract Background The choice of reliable reference genes is a prerequisite for valid results when analyzing gene expression with real-time quantitative PCR (qPCR. This method is frequently applied to study gene expression patterns in immune cells, yet a thorough validation of potential reference genes is still lacking for most leukocyte subtypes and most models of their in vitro stimulation. In the current study, we evaluated the expression stability of common reference genes in two widely used cell culture models-anti-CD3/CD28 activated T cells and lipopolysaccharide stimulated neutrophils-as well as in unselected untreated leukocytes. Results The mRNA expression of 17 (T cells, 7 (neutrophils or 8 (unselected leukocytes potential reference genes was quantified by reverse transcription qPCR, and a ranking of the preselected candidate genes according to their expression stability was calculated using the programs NormFinder, geNorm and BestKeeper. IPO8, RPL13A, TBP and SDHA were identified as suitable reference genes in T cells. TBP, ACTB and SDHA were stably expressed in neutrophils. TBP and SDHA were also the most stable genes in untreated total blood leukocytes. The critical impact of reference gene selection on the estimated target gene expression is demonstrated for IL-2 and FIH expression in T cells. Conclusions The study provides a shortlist of suitable reference genes for normalization of gene expression data in unstimulated and stimulated T cells, unstimulated and stimulated neutrophils and in unselected leukocytes.

  13. Rapid and selective expansion of nonclonotypic T cells in regulatory T cell-deficient, foreign antigen-specific TCR-transgenic scurfy mice: antigen-dependent expansion and TCR analysis.

    Science.gov (United States)

    Sharma, Rahul; Ju, Angela Chiao-Ying; Kung, John T; Fu, Shu Man; Ju, Shyr-Te

    2008-11-15

    Foreign Ag-specific TCR-transgenic (Tg) mice contain a small fraction of T cells bearing the endogenous Vbeta and Valpha chains as well as a population expressing an intermediate level of Tg TCR. Importantly, these minor nonclonotypic populations contain > or = 99% of the CD4(+)Foxp3(+) regulatory T cells (Treg) and, despite low overall Treg expression, peripheral tolerance is maintained. In the OT-II TCR (OVA-specific, Vbeta5(high)Valpha2(high)) Tg scurfy (Sf) mice (OT-II Sf) that lack Treg, nonclonotypic T cells markedly expanded in the periphery but not in the thymus. Expanded T cells expressed memory/effector phenotype and were enriched in blood and inflamed lungs. In contrast, Vbeta5(high)Valpha2(high) clonotypic T cells were not expanded, displayed the naive phenotype, and found mainly in the lymph nodes. Importantly, Vbeta5(neg) T cells were able to transfer multiorgan inflammation in Rag1(-/-) recipients. T cells bearing dual TCR (dual Vbeta or dual Valpha) were demonstrated frequently in the Vbeta5(int) and Valpha2(int) populations. Our study demonstrated that in the absence of Treg, the lack of peripheral expansion of clonotypic T cells is due to the absence of its high-affinity Ag OVA. Thus, the rapid expansion of nonclonotypic T cells in OT-II Sf mice must require Ag (self and foreign) with sufficient affinity. Our study has implications with respect to the roles of Ag and dual TCR in the selection and regulation of Treg and Treg-controlled Ag-dependent T cell expansion in TCR Tg and TCR Tg Sf mice, respectively.

  14. Acute inhibition of selected membrane-proximal mouse T cell receptor signaling by mitochondrial antagonists.

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    Kwangmi Kim

    2009-11-01

    Full Text Available T cells absorb nanometric membrane vesicles, prepared from plasma membrane of antigen presenting cells, via dual receptor/ligand interactions of T cell receptor (TCR with cognate peptide/major histocompatibility complex (MHC plus lymphocyte function-associated antigen 1 (LFA-1 with intercellular adhesion molecule 1. TCR-mediated signaling for LFA-1 activation is also required for the vesicle absorption. Exploiting those findings, we had established a high throughput screening (HTS platform and screened a library for isolation of small molecules inhibiting the vesicle absorption. Follow-up studies confirmed that treatments (1 hour with various mitochondrial antagonists, including a class of anti-diabetic drugs (i.e., Metformin and Phenformin, resulted in ubiquitous inhibition of the vesicle absorption without compromising viability of T cells. Further studies revealed that the mitochondrial drug treatments caused impairment of specific membrane-proximal TCR signaling event(s. Thus, activation of Akt and PLC-gamma1 and entry of extracellular Ca(2+ following TCR stimulation were attenuated while polymerization of monomeric actins upon TCR triggering progressed normally after the treatments. Dynamic F-actin rearrangement concurring with the vesicle absorption was also found to be impaired by the drug treatments, implying that the inhibition by the drug treatments of downstream signaling events (and the vesicle absorption could result from lack of directional relocation of signaling and cell surface molecules. We also assessed the potential application of mitochondrial antagonists as immune modulators by probing effects of the long-term drug treatments (24 hours on viability of resting primary T cells and cell cycle progression of antigen-stimulated T cells. This study unveils a novel regulatory mechanism for T cell immunity in response to environmental factors having effects on mitochondrial function.

  15. Inhibition of T cell proliferation by selective block of Ca(2+)-activated K(+) channels

    DEFF Research Database (Denmark)

    Jensen, B S; Odum, Niels; Jorgensen, N K

    1999-01-01

    cell activation and proliferation has been investigated by using various blockers of IK channels. The Ca(2+)-activated K(+) current in human T cells is shown by the whole-cell voltage-clamp technique to be highly sensitive to clotrimazole, charybdotoxin, and nitrendipine, but not to ketoconazole...

  16. Characterization of HIV-Specific CD4+T Cell Responses against Peptides Selected with Broad Population and Pathogen Coverage

    DEFF Research Database (Denmark)

    Buggert, Marcus; Norstrom, Melissa M.; Czarnecki, Chris

    2012-01-01

    for the identification of HIV-specific CD4+ T cells targeting broadly reactive epitopes in populations with diverse ethnic background stems from the vast genomic variation of HIV and the diversity of the host cellular immune system. Here, we describe a novel epitope selection strategy, PopCover, that aims to resolve...... this challenge, and identify a set of potential HLA class II-restricted HIV epitopes that in concert will provide optimal viral and host coverage. Using this selection strategy, we identified 64 putative epitopes (peptides) located in the Gag, Nef, Env, Pol and Tat protein regions of HIV. In total, 73...... II-restricted epitopes. All together, selection strategies, such as PopCover, might with success be used for the evaluation of antigen-specific CD4+ T cell responses and design of future vaccines....

  17. Structure-activity relationship of 9-methylstreptimidone, a compound that induces apoptosis selectively in adult T-cell leukemia cells.

    Science.gov (United States)

    Takeiri, Masatoshi; Ota, Eisuke; Nishiyama, Shigeru; Kiyota, Hiromasa; Umezawa, Kazuo

    2012-01-01

    We previously reported that 9-methylstreptimidone, a piperidine compound isolated from a culture filtrate of Streptomyces, induces apoptosis selectively in adult T-cell leukemia cells. It was screened for a compound that inhibits LPS-induced NF-kappaB and NO production in mouse macrophages. However, 9-methystreptimidone is poorly obtained from the producing microorganism and difficult to synthesize. Therefore, in the present research, we studied the structure-activity relationship to look for new selective inhibitors. We found that the structure of the unsaturated hydrophobic portion of 9-methylstreptimidone was essential for the inhibition of LPS-induced NO production. Among the 9-methylstreptimidone-related compounds tested, (+/-)-4,alpha-diepi-streptovitacin A inhibited NO production in macrophage-like cells as potently as 9-methylstreptimidone and without cellular toxicity. Moreover, this compound selectively induced apoptosis in adult T-cell leukemia MT-1 cells.

  18. Somatic hypermutation of T cell receptor α chain contributes to selection in nurse shark thymus.

    Science.gov (United States)

    Ott, Jeannine A; Castro, Caitlin D; Deiss, Thaddeus C; Ohta, Yuko; Flajnik, Martin F; Criscitiello, Michael F

    2018-04-17

    Since the discovery of the T cell receptor (TcR), immunologists have assigned somatic hypermutation (SHM) as a mechanism employed solely by B cells to diversify their antigen receptors. Remarkably, we found SHM acting in the thymus on α chain locus of shark TcR. SHM in developing shark T cells likely is catalyzed by activation-induced cytidine deaminase (AID) and results in both point and tandem mutations that accumulate non-conservative amino acid replacements within complementarity-determining regions (CDRs). Mutation frequency at TcRα was as high as that seen at B cell receptor loci (BcR) in sharks and mammals, and the mechanism of SHM shares unique characteristics first detected at shark BcR loci. Additionally, fluorescence in situ hybridization showed the strongest AID expression in thymic corticomedullary junction and medulla. We suggest that TcRα utilizes SHM to broaden diversification of the primary αβ T cell repertoire in sharks, the first reported use in vertebrates. © 2018, Ott et al.

  19. Selective induction of DNA repair pathways in human B cells activated by CD4+ T cells.

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    Xiaosheng Wu

    Full Text Available Greater than 75% of all hematologic malignancies derive from germinal center (GC or post-GC B cells, suggesting that the GC reaction predisposes B cells to tumorigenesis. Because GC B cells acquire expression of the highly mutagenic enzyme activation-induced cytidine deaminase (AID, GC B cells may require additional DNA repair capacity. The goal of this study was to investigate whether normal human B cells acquire enhanced expression of DNA repair factors upon AID induction. We first demonstrated that several DNA mismatch repair, homologous recombination, base excision repair, and ATR signaling genes were overexpressed in GC B cells relative to naïve and memory B cells, reflecting activation of a process we have termed somatic hyperrepair (SHR. Using an in vitro system, we next characterized activation signals required to induce AID expression and SHR. Although AID expression was induced by a variety of polyclonal activators, SHR induction strictly required signals provided by contact with activated CD4+ T cells, and B cells activated in this manner displayed reduced levels of DNA damage-induced apoptosis. We further show the induction of SHR is independent of AID expression, as GC B cells from AID-/-mice retained heightened expression of SHR proteins. In consideration of the critical role that CD4+ T cells play in inducing the SHR process, our data suggest a novel role for CD4+ T cells in the tumor suppression of GC/post-GC B cells.

  20. T cell activation and proliferation following acute exercise in human subjects is altered by storage conditions and mitogen selection.

    Science.gov (United States)

    Siedlik, Jacob A; Deckert, Jake A; Benedict, Stephen H; Bhatta, Anuja; Dunbar, Amanda J; Vardiman, John P; Gallagher, Philip M

    2017-07-01

    Recent work investigating exercise induced changes in immunocompetence suggests that some of the ambiguity in the literature is resultant from different cell isolation protocols and mitogen selection. To understand this effect, we compared post-exercise measures of T cell activation and proliferation using two different stimulation methods (costimulation through CD28 or stimulation with phytohaemagglutinin [PHA]). Further, we investigated whether exercise induced changes are maintained when T cell isolation from whole blood is delayed overnight in either a room temperature or chilled (4°C) environment. As expected, an increased proliferation response was observed post-exercise in T cells isolated from whole blood of previously trained individuals immediately after blood collection. Also, cells stimulated with PHA after resting overnight in whole blood were not adversely impacted by the storage conditions. In contrast, allowing cells to rest overnight in whole blood prior to stimulation through CD28, lessened the proliferation observed by cells following exercise rendering both the room temperature and chilled samples closer to the results seen in the control condition. Changes in early markers of activation (CD25), followed a similar pattern, with activation in PHA stimulated cells remaining fairly robust after overnight storage; whereas cell activation following stimulation through CD3+CD28 was disproportionately decreased by the influence of overnight storage. These findings indicate that decisions regarding cell stimulation methods need to be paired with the timeline for T cell isolation from whole blood. These considerations will be especially important for field based studies of immunocompetence where there is a delay in getting whole blood samples to a lab for processing as well as clinical applications where a failure to isolate T cells in a timely manner may result in loss of the response of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Involvement of regulatory T cells and selected cytokines in the pathogenesis of bronchial asthma

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    Monika Zuśka-Prot

    2016-06-01

    Full Text Available Asthma pathogenesis is complex and involves the interplay of many factors and actions. Airway inflammation in allergic asthma is characterized by an exaggerated activation of T helper type 2 cells, IgE production and infiltration and activation of eosinophils. The results of studies conducted in recent years indicate that the deficit of naturally occurring Foxp3+CD25+CD4+ and Foxp3+CD25+CD8+ regulatory T cells and type 1 regulatory T cells plays a pivotal role in the development of this disease. Moreover, numerous studies have provided convincing evidence that a decrease in IL-10 production and an increase in IL-17 production have an important place in the pathophysiology of asthma. TGF-β is another important cytokine involved in this disease. TGF-β has a paradoxical status in relation to asthma pathogenesis because it seems to play a role in both suppressing and promoting asthma development. This review discusses briefly clinical and experimental data concerning the involvement of T regulatory cells and IL-10, IL-17 and TGF-β in the pathogenesis of asthma.

  2. Changing T cell specificity by retroviral T cell receptor display

    NARCIS (Netherlands)

    Kessels, H. W.; van den Boom, M. D.; Spits, H.; Hooijberg, E.; Schumacher, T. N.

    2000-01-01

    The diversity of the T cell receptor (TCR) repertoire is limited, because of the processes of positive and negative T cell selection. To obtain T cells with specificities beyond the immune system's capacity, we have developed a strategy for retroviral TCR display. In this approach, a library of T

  3. Impact of clonal competition for peptide-MHC complexes on the CD8[superscript +] T-cell repertoire selection in a persistent viral infection

    Energy Technology Data Exchange (ETDEWEB)

    Wynn, Katherine K.; Fulton, Zara; Cooper, Leanne; Silins, Sharon L.; Gras, Stephanie; Archbold, Julia K.; Tynan, Fleur E.; Miles, John J.; McCluskey, James; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv (Monash); (Queensland Inst. of Med. Rsrch.); (Melbourne)

    2008-04-29

    CD8{sup +} T-cell responses to persistent viral infections are characterized by the accumulation of an oligoclonal T-cell repertoire and a reduction in the naive T-cell pool. However, the precise mechanism for this phenomenon remains elusive. Here we show that human cytomegalovirus (HCMV)-specific CD8{sup +} T cells recognizing distinct epitopes from the pp65 protein and restricted through an identical HLA class I allele (HLA B*3508) exhibited either a highly conserved public T-cell repertoire or a private, diverse T-cell response, which was uniquely altered in each donor following in vitro antigen exposure. Selection of a public T-cell receptor (TCR) was coincident with an atypical major histocompatibility complex (MHC)-peptide structure, in that the epitope adopted a helical conformation that bulged from the peptide-binding groove, while a diverse TCR profile was observed in response to the epitope that formed a flatter, more 'featureless' landscape. Clonotypes with biased TCR usage demonstrated more efficient recognition of virus-infected cells, a greater CD8 dependency, and were more terminally differentiated in their phenotype when compared with the T cells expressing diverse TCR. These findings provide new insights into our understanding on how the biology of antigen presentation in addition to the structural features of the pMHC-I might shape the T-cell repertoire and its phenotype.

  4. The stream of precursors that colonizes the thymus proceeds selectively through the early T lineage precursor stage of T cell development

    Science.gov (United States)

    Benz, Claudia; Martins, Vera C.; Radtke, Freddy; Bleul, Conrad C.

    2008-01-01

    T cell development in the thymus depends on continuous colonization by hematopoietic precursors. Several distinct T cell precursors have been identified, but whether one or several independent precursor cell types maintain thymopoiesis is unclear. We have used thymus transplantation and an inducible lineage-tracing system to identify the intrathymic precursor cells among previously described thymus-homing progenitors that give rise to the T cell lineage in the thymus. Extrathymic precursors were not investigated in these studies. Both approaches show that the stream of T cell lineage precursor cells, when entering the thymus, selectively passes through the early T lineage precursor (ETP) stage. Immigrating precursor cells do not exhibit characteristics of double-negative (DN) 1c, DN1d, or DN1e stages, or of populations containing the common lymphoid precursor 2 (CLP-2) or the thymic equivalent of circulating T cell progenitors (CTPs). It remains possible that an unknown hematopoietic precursor cell or previously described extrathymic precursors with a CLP, CLP-2, or CTP phenotype feed into T cell development by circumventing known intrathymic T cell lineage progenitor cells. However, it is clear that of the known intrathymic precursors, only the ETP population contributes significant numbers of T lineage precursors to T cell development. PMID:18458114

  5. A Unique T-Cell Receptor Amino Acid Sequence Selected by Human T-Cell Lymphotropic Virus Type 1 Tax301-309-Specific Cytotoxic T Cells in HLA-A24:02-Positive Asymptomatic Carriers and Adult T-Cell Leukemia/Lymphoma Patients.

    Science.gov (United States)

    Ishihara, Yuko; Tanaka, Yukie; Kobayashi, Seiichiro; Kawamura, Koji; Nakasone, Hideki; Gomyo, Ayumi; Hayakawa, Jin; Tamaki, Masaharu; Akahoshi, Yu; Harada, Naonori; Kusuda, Machiko; Kameda, Kazuaki; Ugai, Tomotaka; Wada, Hidenori; Sakamoto, Kana; Sato, Miki; Terasako-Saito, Kiriko; Kikuchi, Misato; Kimura, Shun-Ichi; Tanihara, Aki; Kako, Shinichi; Uchimaru, Kaoru; Kanda, Yoshinobu

    2017-10-01

    We previously reported that the T-cell receptor (TCR) repertoire of human T-cell lymphotropic virus type 1 (HTLV-1) Tax 301-309 -specific CD8 + cytotoxic T cells (Tax 301-309 -CTLs) was highly restricted and a particular amino acid sequence motif, the PDR motif, was conserved among HLA-A*24:02-positive (HLA-A*24:02 + ) adult T-cell leukemia/lymphoma (ATL) patients who had undergone allogeneic hematopoietic cell transplantation (allo-HSCT). Furthermore, we found that donor-derived PDR + CTLs selectively expanded in ATL long-term HSCT survivors with strong CTL activity against HTLV-1. On the other hand, the TCR repertoires in Tax 301-309 -CTLs of asymptomatic HTLV-1 carriers (ACs) remain unclear. In this study, we directly identified the DNA sequence of complementarity-determining region 3 (CDR3) of the TCR-β chain of Tax 301-309 -CTLs at the single-cell level and compared not only the TCR repertoires but also the frequencies and phenotypes of Tax 301-309 -CTLs between ACs and ATL patients. We did not observe any essential difference in the frequencies of Tax 301-309 -CTLs between ACs and ATL patients. In the single-cell TCR repertoire analysis of Tax 301-309 -CTLs, 1,458 Tax 301-309 -CTLs and 140 clones were identified in this cohort. Tax 301-309 -CTLs showed highly restricted TCR repertoires with a strongly biased usage of BV7, and PDR, the unique motif in TCR-β CDR3, was exclusively observed in all ACs and ATL patients. However, there was no correlation between PDR + CTL frequencies and HTLV-1 proviral load (PVL). In conclusion, we have identified, for the first time, a unique amino acid sequence, PDR, as a public TCR-CDR3 motif against Tax in HLA-A*24:02 + HTLV-1-infected individuals. Further investigations are warranted to elucidate the role of the PDR + CTL response in the progression from carrier state to ATL. IMPORTANCE ATL is an aggressive T-cell malignancy caused by HTLV-1 infection. The HTLV-1 regulatory protein Tax aggressively promotes the

  6. Selective Destruction of Interleukin 23–Induced Expansion of a Major Antigen–Specific γδ T-Cell Subset in Patients With Tuberculosis

    Science.gov (United States)

    Gu, Jin; Xiao, Heping; Liang, Shanshan; Yang, Enzhuo; Yang, Rui; Huang, Dan; Chen, Crystal; Wang, Feifei; Shen, Ling; Chen, Zheng W.

    2017-01-01

    Abstract A loss of antigen-specific T-cell responses due to defective cytokine signaling during infections has not been reported. We hypothesize that tuberculosis can destroy signaling effects of selective cytokine(s) and induce exhaustion of antigen-specific T cells. To test this hypothesis, mechanistic studies were performed to examine whether and how tuberculosis blocked interleukin 23 (IL-23) and interleukin 2 (IL-2) signaling effects on a major human γδ T-cell subpopulation, phosphoantigen HMBPP–specific Vγ2Vδ2 T cells. IL-23 and IL-2 significantly expanded HMBPP-stimulated Vγ2Vδ2 T cells from subjects with latent tuberculosis infection, and IL-2 synergized the effect of IL-23. IL-23–induced expansion of Vγ2Vδ2 T cells involved STAT3. Surprisingly, patients with tuberculosis exhibited a selective destruction of IL-23–induced expansion of these cells. The tuberculosis-driven destruction of IL-23 signaling coincided with decreases of expression and phosphorylation of STAT3. Interestingly, impairing of STAT3 was linked to marked increases in the microRNAs (miRNAs) hsa-miR-337-3p and hsa-miR-125b-5p in Vγ2Vδ2 T cells from patients with tuberculosis. Downregulation of hsa-miR-337-3p and hsa-miR-125b-5p by miRNA sponges improved IL-23–mediated expansion of Vγ2Vδ2 T cells and restored the ability of these cells to produce anti–tuberculosis cytokines. These results support our hypothesis that tuberculosis can selectively impair a cytokine effect while sparing another and can induce exhaustion of T cells in response to the respective cytokine. PMID:27789724

  7. Selection of restriction specificities of virus-specific cytotoxic T cells in the thymus: no evidence for a crucial role of antigen-presenting cells

    International Nuclear Information System (INIS)

    Zinkernagel, R.M.

    1982-01-01

    The proposal was tested that (P1 X P2) F1 leads to P1 irradiation bone marrow chimeras expressed predominantly P1-restricted T cells because donor derived stem cells were exposed to recipient derived antigen-presenting cells in the thymus. Because P1 recipient-derived antigen-presenting cells are replaced only slowly after 6-8 wk by (P1 X P2) donor-derived antigen-presenting cells in the thymus and because replenished pools of mature T cells may by then prevent substantial numbers of P2-restricted T cells to be generated, a large portion of thymus cells and mature T cells were eliminated using the following treatments of 12-20-wk-old (P1 X P2) F1 leads to P1 irradiation bone marrow chimeras: (a) cortisone plus antilymphocyte serum, (b) Cytoxan, (c) three doses of sublethal irradiation (300 rad) 2d apart, and (d) lethal irradiation (850 rad) and reconstitution with T cell-depleted (P1 X P2) F1 stem cells. 12-20 wk after this second treatment, (P1 X P2) leads to P1 chimeras were infected with vaccinia-virus. Virus-specific cytotoxic T cell reactivity was expressed by chimeric T cells of (P1 X P[2) F1 origin and was restricted predominantly to P1. Virus-specific cytotoxic T cells, therefore, do not seem to be selected to measurable extent by the immigrating donor-derived antigen-presenting cells in the thymus; their selection depends apparently from the recipient-derived radioresistant thymus cells

  8. Heat shock protein 90-mediated peptide-selective presentation of cytosolic tumor antigen for direct recognition of tumors by CD4(+) T cells.

    Science.gov (United States)

    Tsuji, Takemasa; Matsuzaki, Junko; Caballero, Otavia L; Jungbluth, Achim A; Ritter, Gerd; Odunsi, Kunle; Old, Lloyd J; Gnjatic, Sacha

    2012-04-15

    Tumor Ag-specific CD4(+) T cells play important functions in tumor immunosurveillance, and in certain cases they can directly recognize HLA class II-expressing tumor cells. However, the underlying mechanism of intracellular Ag presentation to CD4(+) T cells by tumor cells has not yet been well characterized. We analyzed two naturally occurring human CD4(+) T cell lines specific for different peptides from cytosolic tumor Ag NY-ESO-1. Whereas both lines had the same HLA restriction and a similar ability to recognize exogenous NY-ESO-1 protein, only one CD4(+) T cell line recognized NY-ESO-1(+) HLA class II-expressing melanoma cells. Modulation of Ag processing in melanoma cells using specific molecular inhibitors and small interfering RNA revealed a previously undescribed peptide-selective Ag-presentation pathway by HLA class II(+) melanoma cells. The presentation required both proteasome and endosomal protease-dependent processing mechanisms, as well as cytosolic heat shock protein 90-mediated chaperoning. Such tumor-specific pathway of endogenous HLA class II Ag presentation is expected to play an important role in immunosurveillance or immunosuppression mediated by various subsets of CD4(+) T cells at the tumor local site. Furthermore, targeted activation of tumor-recognizing CD4(+) T cells by vaccination or adoptive transfer could be a suitable strategy for enhancing the efficacy of tumor immunotherapy.

  9. Distinct Escape Pathway by Hepatitis C Virus Genotype 1a from a Dominant CD8+ T Cell Response by Selection of Altered Epitope Processing.

    Science.gov (United States)

    Walker, Andreas; Skibbe, Kathrin; Steinmann, Eike; Pfaender, Stephanie; Kuntzen, Thomas; Megger, Dominik A; Groten, Svenja; Sitek, Barbara; Lauer, Georg M; Kim, Arthur Y; Pietschmann, Thomas; Allen, Todd M; Timm, Joerg

    2016-01-01

    Antiviral CD8(+) T cells are a key component of the adaptive immune response against HCV, but their impact on viral control is influenced by preexisting viral variants in important target epitopes and the development of viral escape mutations. Immunodominant epitopes highly conserved across genotypes therefore are attractive for T cell based prophylactic vaccines. Here, we characterized the CD8(+) T cell response against the highly conserved HLA-B*51-restricted epitope IPFYGKAI1373-1380 located in the helicase domain of NS3 in people who inject drugs (PWID) exposed predominantly to HCV genotypes 1a and 3a. Despite this epitope being conserved in both genotypes, the corresponding CD8(+) T cell response was detected only in PWID infected with genotype 3a and HCV-RNA negative PWID, but not in PWID infected with genotype 1a. In genotype 3a, the detection of strong CD8(+) T cell responses was associated with epitope variants in the autologous virus consistent with immune escape. Analysis of viral sequences from multiple cohorts confirmed HLA-B*51-associated escape mutations inside the epitope in genotype 3a, but not in genotype 1a. Here, a distinct substitution in the N-terminal flanking region located 5 residues upstream of the epitope (S1368P; P = 0.00002) was selected in HLA-B*51-positive individuals. Functional assays revealed that the S1368P substitution impaired recognition of target cells presenting the endogenously processed epitope. The results highlight that, despite an epitope being highly conserved between two genotypes, there are major differences in the selected viral escape pathways and the corresponding T cell responses. HCV is able to evolutionary adapt to CD8(+) T cell immune pressure in multiple ways. Beyond selection of mutations inside targeted epitopes, this study demonstrates that HCV inhibits epitope processing by modification of the epitope flanking region under T cell immune pressure. Selection of a substitution five amino acids upstream of the

  10. Selective enrichment of Th1 CD45RBlow CD4+ T cells in autoimmune infiltrates in experimental allergic encephalomyelitis

    DEFF Research Database (Denmark)

    Renno, T; Zeine, R; Girard, J M

    1994-01-01

    The cytokine effector status of CD4+ T cells from lymph nodes (LN) and the central nervous system (CNS) of SJL/J mice immunized with autoantigen in adjuvant for the induction of experimental allergic encephalomyelitis (EAE) was compared. CD4+ T cells were FACS sorted based on the levels...... in the sorted populations. CD45RBlow cells constituted a minority of CD4+ cells in the LN and expressed elevated levels of IL-2, IFN-gamma, and IL-4 mRNA, whereas the CD45RBlow CD4+ population did not express detectable message for these cytokines under linear PCR conditions. By contrast to the LN, CD4+ cells...... of expression of the activation marker CD45RB. Low levels of expression of this surface marker are induced by antigen recognition and are associated with 'effector' T cell function. Reverse transcriptase polymerase chain reaction (PCR) was used to analyze the expression of different T cell cytokine genes...

  11. Selective corneal optical aberration (SCOA) for customized ablation

    Science.gov (United States)

    Jean, Benedikt J.; Bende, Thomas

    2001-06-01

    Wavefront analysis still have some technical problems which may be solved within the next years. There are some limitations to use wavefront as a diagnostic tool for customized ablation alone. An ideal combination would be wavefront and topography. Meanwhile Selective Corneal Aberration is a method to visualize the optical quality of a measured corneal surface. It is based on a true measured 3D elevation information of a video topometer. Thus values can be interpreted either using Zernike polynomials or visualized as a so called color coded surface quality map. This map gives a quality factor (corneal aberration) for each measured point of the cornea.

  12. Evaluation of natural regulatory T cells in subjects with selective IgA deficiency: from senior idea to novel opportunities.

    Science.gov (United States)

    Soheili, Habib; Abolhassani, Hassan; Arandi, Narges; Khazaei, Hossein Ali; Shahinpour, Shervin; Hirbod-Mobarakeh, Armin; Rezaei, Nima; Aghamohammadi, Asghar

    2013-01-01

    Selective IgA deficiency (SIgAD) is the most common primary immunodeficiency disorder, which is characterized by significantly decreased serum levels of IgA. Abnormalities of CD4+CD25(high)forkhead box P3 (FoxP3)+ regulatory T cells (T(reg)) have been shown in association with autoimmune and inflammatory disorders. In order to evaluate the relationship between autoimmunity and T(reg) in SIgAD, we studied 26 IgA-deficient patients (aged 4-17 years) with serum IgA levels 2.36%. Autoimmunity was recorded in 9 patients (53.3%) of G1 and only 1 patient of G2, respectively (p = 0.034). Although a defect in class switching recombination was observed in 40% of the patients in G1, none of the G2 patients had such a defect (p = 0.028). This study showed decreased proportions of T(reg) in SIgAD patients, particularly in those with signs of chronic inflammation. Copyright © 2012 S. Karger AG, Basel.

  13. PRMT5 Is Upregulated in HTLV-1-Mediated T-Cell Transformation and Selective Inhibition Alters Viral Gene Expression and Infected Cell Survival

    Directory of Open Access Journals (Sweden)

    Amanda R. Panfil

    2015-12-01

    Full Text Available Human T-cell leukemia virus type-1 (HTLV-1 is a tumorigenic retrovirus responsible for development of adult T-cell leukemia/lymphoma (ATLL. This disease manifests after a long clinical latency period of up to 2–3 decades. Two viral gene products, Tax and HBZ, have transforming properties and play a role in the pathogenic process. Genetic and epigenetic cellular changes also occur in HTLV-1-infected cells, which contribute to transformation and disease development. However, the role of cellular factors in transformation is not completely understood. Herein, we examined the role of protein arginine methyltransferase 5 (PRMT5 on HTLV-1-mediated cellular transformation and viral gene expression. We found PRMT5 expression was upregulated during HTLV-1-mediated T-cell transformation, as well as in established lymphocytic leukemia/lymphoma cell lines and ATLL patient PBMCs. shRNA-mediated reduction in PRMT5 protein levels or its inhibition by a small molecule inhibitor (PRMT5i in HTLV-1-infected lymphocytes resulted in increased viral gene expression and decreased cellular proliferation. PRMT5i also had selective toxicity in HTLV-1-transformed T-cells. Finally, we demonstrated that PRMT5 and the HTLV-1 p30 protein had an additive inhibitory effect on HTLV-1 gene expression. Our study provides evidence for PRMT5 as a host cell factor important in HTLV-1-mediated T-cell transformation, and a potential target for ATLL treatment.

  14. Defect in negative selection in lpr donor-derived T cells differentiating in non-lpr host thymus

    International Nuclear Information System (INIS)

    Matsumoto, K.; Yoshikai, Y.; Asano, T.; Himeno, K.; Iwasaki, A.; Nomoto, K.

    1991-01-01

    Transplantation of bone marrow cells of lpr/lpr mice into irradiated normal mice fails to develop massive lymphadenopathy or autoimmunity but causes severe graft-vs.-host-like syndrome. To elucidate an abnormality of lpr/lpr bone marrow-derived T cells, we transplanted bone marrow cells of Mlsb lpr/lpr mice into H-2-compatible Mlsa non-lpr mice. Although lpr/lpr T cell precursors repopulated the host thymus as well as +/+ cells, a proportion of CD4+CD8+ cells decreased, and that of both CD4- and CD8- single-positive cells increased compared with those of +/+ recipients. Notably, in MRL/lpr----AKR and C3H/lpr----AKR chimeras, CD4 single-positive thymocytes contained an increased number of V beta 6+ cells in spite of potentially deleting alleles of Mlsa, whereas V beta 6+ mature T cells were deleted in the MRL/+ ----AKR and C3H/+ ----AKR chimeras. There was no difference between MRL/+ ----AKR and MRL/lpr----AKR chimeras in their proportion of V beta 3+ cells because both host and donor strain lack the deleting alleles. Interleukin 2 receptor expression of mature T cells, in the thymus and lymph node, was obviously higher in the MRL/lpr----AKR chimeras, in particular in the forbidden V beta 6+ subset. Moreover, lpr donor-derived peripheral T cells showed vigorous anti-CD3 response. These results indicate that lpr-derived T cells escape not only tolerance-related clonal deletion but also some induction of unresponsiveness in the non-lpr thymus

  15. Alantolactone selectively ablates acute myeloid leukemia stem and progenitor cells

    Directory of Open Access Journals (Sweden)

    Yahui Ding

    2016-09-01

    Full Text Available Abstract Background The poor outcomes for patients diagnosed with acute myeloid leukemia (AML are largely attributed to leukemia stem cells (LSCs which are difficult to eliminate with conventional therapy and responsible for relapse. Thus, new therapeutic strategies which could selectively target LSCs in clinical leukemia treatment and avoid drug resistance are urgently needed. However, only a few small molecules have been reported to show anti-LSCs activity. Methods The aim of the present study was to identify alantolactone as novel agent that can ablate acute myeloid leukemia stem and progenitor cells from AML patient specimens and evaluate the anticancer activity of alantolactone in vitro and in vivo. Results The present study is the first to demonstrate that alantolactone, a prominent eudesmane-type sesquiterpene lactone, could specifically ablate LSCs from AML patient specimens. Furthermore, in comparison to the conventional chemotherapy drug, cytosine arabinoside (Ara-C, alantolactone showed superior effects of leukemia cytotoxicity while sparing normal hematopoietic cells. Alantolactone induced apoptosis with a dose-dependent manner by suppression of NF-kB and its downstream target proteins. DMA-alantolactone, a water-soluble prodrug of alantolactone, could suppress tumor growth in vivo. Conclusions Based on these results, we propose that alantolactone may represent a novel LSCs-targeted therapy and eudesmane-type sesquiterpene lactones offer a new scaffold for drug discovery towards anti-LSCs agents.

  16. Ablation of selected conducting layers by fiber laser

    Science.gov (United States)

    Pawlak, Ryszard; Tomczyk, Mariusz; Walczak, Maria

    2014-08-01

    Laser Direct Writing (LDW) are used in the manufacture of electronic circuits, pads, and paths in sub millimeter scale. They can also be used in the sensors systems. Ablative laser writing in a thin functional layer of material deposited on the dielectric substrate is one of the LDW methods. Nowadays functional conductive layers are composed from graphene paint or nanosilver paint, indium tin oxide (ITO), AgHTTM and layers containing carbon nanotubes. Creating conducting structures in transparent layers (ITO, AgHT and carbon nanotubes layers) may have special importance e.g. for flexi electronics. The paper presents research on the fabrication of systems of paths and appropriate pattern systems of paths and selected electronic circuits in AgHTTM and ITO layers deposited on glass and polymer substrates. An influence of parameters of ablative fiber laser treatment in nanosecond regime as well as an influence of scanning mode of laser beam on the pattern fidelity and on electrical parameters of a generated circuit was investigated.

  17. MR1-restricted MAIT cells display ligand discrimination and pathogen selectivity through distinct T cell receptor usage

    DEFF Research Database (Denmark)

    Gold, Marielle C.; McLaren, James E.; Reistetter, Joseph A.

    2014-01-01

    Mucosal-associated invariant T (MAIT) cells express a semi-invariant T cell receptor (TCR) that detects microbial metabolites presented by the nonpolymorphic major histocompatibility complex (MHC)-like molecule MR1. The highly conserved nature of MR1 in conjunction with biased MAIT TCRα chain usa...

  18. Alcohol septal ablation: patient selection and rationality of its application

    Directory of Open Access Journals (Sweden)

    М. Г. Каштанов

    2017-04-01

    Full Text Available The article looks at some aspects of selecting patients with obstructive hypertrophic cardiomyopathy for alcohol septal ablation (ASA procedure. Based on the world’s experience and in the context of evidence-based medicine, the current positions of ASA in complex treatment of obstructive hypertrophic cardiomyopathy are described. Received 29 September 2016. Accepted 9 January 2017.Funding: The study had no sponsorship.Conflict of interest: The authors declare no conflict of interest.Author contributionsData collection and analysis: Kashtanov M.G. Drafting the article: Kashtanov M.G. Critical revision: Kashtanov M.G., Idov E.M., Chernyshev S.D., Kardapoltsev L.V., Berdnikov S.V.

  19. The immune privilege of the eye: human retinal pigment epithelial cells selectively modulate T-cell activation in vitro

    DEFF Research Database (Denmark)

    Kaestel, Charlotte G; Lovato, Paola; Ødum, Niels

    2005-01-01

    PURPOSE: To examine the effect of human retinal pigment epithelial (RPE) cells on phytohemagglutinin (PHA) activation of T cells. METHODS: Resting peripheral blood lymphocytes (PBLs) were stimulated with PHA with or without the presence of gamma-irradiated RPE cells. Proliferation and the cell...... in cell culture supernatant was measured by ELISA. RESULTS: Human RPE cells were found to suppress PHA-induced proliferation, cyclin A, IL-2R-alpha and -gamma, and CD71 expression and decrease the production of IL-2; but RPE cells do not inhibit the PHA-induced expression of early activation markers CD69......, MHC class I and II, and of cyclin D of the PBLs. CONCLUSIONS: These results are the first to indicate that RPE cells impede generation of activated T cells by interfering with the induction of high-affinity IL-2R-alphabetagamma, IL-2 production, and the expression of CD71 and cyclin A....

  20. Epigenetic silencing of V(DJ recombination is a major determinant for selective differentiation of mucosal-associated invariant t cells from induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Yutaka Saito

    Full Text Available Mucosal-associated invariant T cells (MAITs are innate-like T cells that play a pivotal role in the host defense against infectious diseases, and are also implicated in autoimmune diseases, metabolic diseases, and cancer. Recent studies have shown that induced pluripotent stem cells (iPSCs derived from MAITs selectively redifferentiate into MAITs without altering their antigen specificity. Such a selective differentiation is a prerequisite for the use of MAITs in cell therapy and/or regenerative medicine. However, the molecular mechanisms underlying this phenomenon remain unclear. Here, we performed methylome and transcriptome analyses of MAITs during the course of differentiation from iPSCs. Our multi-omics analyses revealed that recombination-activating genes (RAG1 and RAG2 and DNA nucleotidylexotransferase (DNTT were highly methylated with their expression being repressed throughout differentiation. Since these genes are essential for V(DJ recombination of the T cell receptor (TCR locus, this indicates that nascent MAITs are kept from further rearrangement that may alter their antigen specificity. Importantly, we found that the repression of RAGs was assured in two layers: one by the modulation of transcription factors for RAGs, and the other by DNA methylation at the RAG loci. Together, our study provides a possible explanation for the unaltered antigen specificity in the selective differentiation of MAITs from iPSCs.

  1. High resolution selective multilayer laser processing by nanosecond laser ablation of metal nanoparticle films

    International Nuclear Information System (INIS)

    Ko, Seung H.; Pan Heng; Hwang, David J.; Chung, Jaewon; Ryu, Sangil; Grigoropoulos, Costas P.; Poulikakos, Dimos

    2007-01-01

    Ablation of gold nanoparticle films on polymer was explored using a nanosecond pulsed laser, with the goal to achieve feature size reduction and functionality not amenable with inkjet printing. The ablation threshold fluence for the unsintered nanoparticle deposit was at least ten times lower than the reported threshold for the bulk film. This could be explained by the combined effects of melting temperature depression, lower conductive heat transfer loss, strong absorption of the incident laser beam, and the relatively weak bonding between nanoparticles. The ablation physics were verified by the nanoparticle sintering characterization, ablation threshold measurement, time resolved ablation plume shadowgraphs, analysis of ablation ejecta, and the measurement and calculation of optical properties. High resolution and clean feature fabrication with small energy and selective multilayer processing are demonstrated

  2. The interleukin-15 system suppresses T cell-mediated autoimmunity by regulating negative selection and nT(H)17 cell homeostasis in the thymus.

    Science.gov (United States)

    Hou, Mau-Sheng; Huang, Shih-Ting; Tsai, Ming-Han; Yen, Ching-Cheng; Lai, Yein-Gei; Liou, Yae-Huei; Lin, Chih-Kung; Liao, Nan-Shih

    2015-01-01

    The interleukin-15 (IL-15) system is important for regulating both innate and adaptive immune responses, however, its role in autoimmune disease remained unclear. Here we found that Il15(-/-) and Il15ra(-/-) mice spontaneously developed late-onset autoimmune phenotypes. CD4(+) T cells of the knockout mice showed elevated autoreactivity as demonstrated by the induction of lymphocyte infiltration in the lacrimal and salivary glands when transferred into nude mice. The antigen-presenting cells in the thymic medullary regions expressed IL-15 and IL-15Rα, whose deficiency resulted in insufficient negative selection and elevated number of natural IL-17A-producing CD4(+) thymocytes. These findings reveal previously unknown functions of the IL-15 system in thymocyte development, and thus a new layer of regulation in T cell-mediated autoimmunity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Inactive Gingipains from P. gingivalis Selectively Skews T Cells toward a Th17 Phenotype in an IL-6 Dependent Manner

    Directory of Open Access Journals (Sweden)

    Jan Potempa

    2017-04-01

    Full Text Available Gingipain cysteine proteases are considered key virulence factors of Porphyromonas gingivalis. They significantly influence antibacterial and homeostatic functions of macrophages, neutrophils, the complement system, and cytokine networks. Recent data indicate the role of P. gingivalis in T cell differentiation; however, the involvement of gingipains in this process remains elusive. Therefore, the aim of this study was to investigate the contribution of danger signals triggered by the gingipains on the generation of Th17 cells, which play a key role in protection against bacterial diseases but may cause chronic inflammation and bone resorption. To this end we compared the effects of the wild-type strain of P. gingivalis (W83 with its isogenic mutant devoid of gingipain activity (ΔKΔRAB, and bacterial cells pretreated with a highly-specific inhibitor of gingipains activity (KYTs. Antigen presenting cells (APCs, both professional (dendritic cells, and non-professional (gingival keratinocytes, exposed to viable bacteria expressed high amounts of cytokines (IL-6, IL-21, IL-23. These cytokines are reported to either stimulate or balance the Th17-dependent immune response. Surprisingly, cells infected with P. gingivalis devoid of gingipain activity showed increased levels of all tested cytokines compared to bacteria with fully active enzymes. The effect was dependent on both the reduction of cytokine proteolysis and the lack of cross-talk with other bacterial virulence factors, including LPS and fimbriae that induce de novo synthesis of cytokines. The profile of lymphocyte T differentiation from naive T cells showed enhanced generation of Th17 in response to bacteria with inactive gingipains. Moreover, we found that gingipain-dependent induction of Th17 cells was highly specific, since other T cell-subsets remained unchanged. Finally, inhibition of IL-6 signaling in dendritic cells led to a significant depletion of the Th17 population. Cumulatively

  4. Inactive Gingipains from P. gingivalis Selectively Skews T Cells toward a Th17 Phenotype in an IL-6 Dependent Manner.

    Science.gov (United States)

    Glowczyk, Izabela; Wong, Alicia; Potempa, Barbara; Babyak, Olena; Lech, Maciej; Lamont, Richard J; Potempa, Jan; Koziel, Joanna

    2017-01-01

    Gingipain cysteine proteases are considered key virulence factors of Porphyromonas gingivalis . They significantly influence antibacterial and homeostatic functions of macrophages, neutrophils, the complement system, and cytokine networks. Recent data indicate the role of P. gingivalis in T cell differentiation; however, the involvement of gingipains in this process remains elusive. Therefore, the aim of this study was to investigate the contribution of danger signals triggered by the gingipains on the generation of Th17 cells, which play a key role in protection against bacterial diseases but may cause chronic inflammation and bone resorption. To this end we compared the effects of the wild-type strain of P. gingivalis (W83) with its isogenic mutant devoid of gingipain activity (ΔKΔRAB), and bacterial cells pretreated with a highly-specific inhibitor of gingipains activity (KYTs). Antigen presenting cells (APCs), both professional (dendritic cells), and non-professional (gingival keratinocytes), exposed to viable bacteria expressed high amounts of cytokines (IL-6, IL-21, IL-23). These cytokines are reported to either stimulate or balance the Th17-dependent immune response. Surprisingly, cells infected with P. gingivalis devoid of gingipain activity showed increased levels of all tested cytokines compared to bacteria with fully active enzymes. The effect was dependent on both the reduction of cytokine proteolysis and the lack of cross-talk with other bacterial virulence factors, including LPS and fimbriae that induce de novo synthesis of cytokines. The profile of lymphocyte T differentiation from naive T cells showed enhanced generation of Th17 in response to bacteria with inactive gingipains. Moreover, we found that gingipain-dependent induction of Th17 cells was highly specific, since other T cell-subsets remained unchanged. Finally, inhibition of IL-6 signaling in dendritic cells led to a significant depletion of the Th17 population. Cumulatively, this study

  5. Thymic commitment of regulatory T cells is a pathway of TCR-dependent selection that isolates repertoires undergoing positive or negative selection.

    Science.gov (United States)

    Coutinho, A; Caramalho, I; Seixas, E; Demengeot, J

    2005-01-01

    The seminal work of Le Douarin and colleagues (Ohki et al. 1987; Ohki et al. 1988; Salaun et al. 1990; Coutinho et al. 1993) first demonstrated that peripheral tissue-specific tolerance is centrally established in the thymus, by epithelial stromal cells (TEC). Subsequent experiments have shown that TEC-tolerance is dominant and mediated by CD4 regulatory T cells (Treg) that are generated intrathymically by recognition of antigens expressed on TECs (Modigliani et al. 1995; Modigliani et al. 1996a). From these and other observations, in 1996 Modigliani and colleagues derived a general model for the establishment and maintenance of natural tolerance (MM96) (Modigliani et al. 1996b), with two central propositions: (1) T cell receptor (TCR)-dependent sorting of emergent repertoires generates TEC-specific Treg displaying the highest TCR self-affinities below deletion thresholds, thus isolating repertoires undergoing positive and negative selection; (2) Treg are intrathymically committed (and activated) for a unique differentiative pathway with regulatory effector functions. The model explained the embryonic/perinatal time window of natural tolerance acquisition, by developmental programs determining (1) TCR multireactivity, (2) the cellular composition in the thymic stroma (relative abundance of epithelial vs hemopoietic cells), and (3) the dynamics of peripheral lymphocyte pools, built by accumulation of recent thymic emigrants (RTE) that remain recruitable to regulatory functions. We discuss here the MM96 in the light of recent results demonstrating the promiscuous expression of tissue-specific antigens by medullary TECs (Derbinski et al. 2001; Anderson et al. 2002; Gotter et al. 2004) and indicating that Treg represent a unique differentiative pathway (Fontenot et al. 2003; Hori et al. 2003; Khattri et al. 2003), which is adopted by CD4 T cells with high avidity for TEC-antigens (Bensinger et al. 2001; Jordan et al. 2001; Apostolou et al. 2002). In the likelihood that

  6. An Antigen-Presenting and Apoptosis-Inducing Polymer Microparticle Prolongs Alloskin Graft Survival by Selectively and Markedly Depleting Alloreactive CD8+ T Cells

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2017-06-01

    Full Text Available Selectively depleting the pathogenic T cells is a fundamental strategy for the treatment of allograft rejection and autoimmune disease since it retains the overall immune function of host. The concept of killer artificial antigen-presenting cells (KaAPCs has been developed by co-coupling peptide–major histocompatibility complex (pMHC multimer and anti-Fas monoclonal antibody (mAb onto the polymeric microparticles (MPs to induce the apoptosis of antigen-specific T cells. But little information is available about its in vivo therapeutic potential and mechanism. In this study, polyethylenimine (PEI-coated poly lactic-co-glycolic acid microparticle (PLGA MP was fabricated as a cell-sized scaffold to covalently co-couple H-2Kb-Ig dimer and anti-Fas mAb for the generation of alloantigen-presenting and apoptosis-inducing MPs. Intravenous infusions of the biodegradable KaAPCs prolonged the alloskin graft survival for 43 days in a single MHC-mismatched murine model, depleted the most of H-2Kb-alloreactive CD8+ T cells in peripheral blood, spleen, and alloskin graft in an antigen-specific manner and anti-Fas-dependent fashion. The cell-sized KaAPCs circulated throughout vasculature into liver, kidney, spleen, lymph nodes, lung, and heart, but few ones into local allograft at early stage, with a retention time up to 36 h in vivo. They colocalized with CD8+ T cells in secondary lymphoid organs while few ones contacted with CD4+ T cells, B cells, macrophage, and dendritic cells, or internalized by phagocytes. Importantly, the KaAPC treatment did not significantly impair the native T cell repertoire or non-pathogenic immune cells, did not obviously suppress the overall immune function of host, and did not lead to visible organ toxicity. Our results strongly document the high potential of PLGA MP-based KaAPCs as a novel antigen-specific immunotherapy for allograft rejection and autoimmune disorder. The in vivo mechanism of alloinhibition, tissue

  7. Glutathione Primes T Cell Metabolism for Inflammation

    DEFF Research Database (Denmark)

    Mak, Tak W.; Grusdat, Melanie; Duncan, Gordon S.

    2017-01-01

    the activation of mammalian target of rapamycin-1 (mTOR) and expression of NFAT and Myc transcription factors, abrogating the energy utilization and Myc-dependent metabolic reprogramming that allows activated T cells to switch to glycolysis and glutaminolysis. In vivo, T-cell-specific ablation of murine Gclc...

  8. γδ T Cells Support Pancreatic Oncogenesis by Restraining αβ T Cell Activation.

    Science.gov (United States)

    Daley, Donnele; Zambirinis, Constantinos Pantelis; Seifert, Lena; Akkad, Neha; Mohan, Navyatha; Werba, Gregor; Barilla, Rocky; Torres-Hernandez, Alejandro; Hundeyin, Mautin; Mani, Vishnu Raj Kumar; Avanzi, Antonina; Tippens, Daniel; Narayanan, Rajkishen; Jang, Jung-Eun; Newman, Elliot; Pillarisetty, Venu Gopal; Dustin, Michael Loran; Bar-Sagi, Dafna; Hajdu, Cristina; Miller, George

    2016-09-08

    Inflammation is paramount in pancreatic oncogenesis. We identified a uniquely activated γδT cell population, which constituted ∼40% of tumor-infiltrating T cells in human pancreatic ductal adenocarcinoma (PDA). Recruitment and activation of γδT cells was contingent on diverse chemokine signals. Deletion, depletion, or blockade of γδT cell recruitment was protective against PDA and resulted in increased infiltration, activation, and Th1 polarization of αβT cells. Although αβT cells were dispensable to outcome in PDA, they became indispensable mediators of tumor protection upon γδT cell ablation. PDA-infiltrating γδT cells expressed high levels of exhaustion ligands and thereby negated adaptive anti-tumor immunity. Blockade of PD-L1 in γδT cells enhanced CD4(+) and CD8(+) T cell infiltration and immunogenicity and induced tumor protection suggesting that γδT cells are critical sources of immune-suppressive checkpoint ligands in PDA. We describe γδT cells as central regulators of effector T cell activation in cancer via novel cross-talk. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Effect of cytomegalovirus co-infection on normalization of selected T-cell subsets in children with perinatally acquired HIV infection treated with combination antiretroviral therapy.

    Science.gov (United States)

    Kapetanovic, Suad; Aaron, Lisa; Montepiedra, Grace; Anthony, Patricia; Thuvamontolrat, Kasalyn; Pahwa, Savita; Burchett, Sandra; Weinberg, Adriana; Kovacs, Andrea

    2015-01-01

    We examined the effect of cytomegalovirus (CMV) co-infection and viremia on reconstitution of selected CD4+ and CD8+ T-cell subsets in perinatally HIV-infected (PHIV+) children ≥ 1-year old who participated in a partially randomized, open-label, 96-week combination antiretroviral therapy (cART)-algorithm study. Participants were categorized as CMV-naïve, CMV-positive (CMV+) viremic, and CMV+ aviremic, based on blood, urine, or throat culture, CMV IgG and DNA polymerase chain reaction measured at baseline. At weeks 0, 12, 20 and 40, T-cell subsets including naïve (CD62L+CD45RA+; CD95-CD28+), activated (CD38+HLA-DR+) and terminally differentiated (CD62L-CD45RA+; CD95+CD28-) CD4+ and CD8+ T-cells were measured by flow cytometry. Of the 107 participants included in the analysis, 14% were CMV+ viremic; 49% CMV+ aviremic; 37% CMV-naïve. In longitudinal adjusted models, compared with CMV+ status, baseline CMV-naïve status was significantly associated with faster recovery of CD8+CD62L+CD45RA+% and CD8+CD95-CD28+% and faster decrease of CD8+CD95+CD28-%, independent of HIV VL response to treatment, cART regimen and baseline CD4%. Surprisingly, CMV status did not have a significant impact on longitudinal trends in CD8+CD38+HLA-DR+%. CMV status did not have a significant impact on any CD4+ T-cell subsets. In this cohort of PHIV+ children, the normalization of naïve and terminally differentiated CD8+ T-cell subsets in response to cART was detrimentally affected by the presence of CMV co-infection. These findings may have implications for adjunctive treatment strategies targeting CMV co-infection in PHIV+ children, especially those that are now adults or reaching young adulthood and may have accelerated immunologic aging, increased opportunistic infections and aging diseases of the immune system.

  10. Effect of cytomegalovirus co-infection on normalization of selected T-cell subsets in children with perinatally acquired HIV infection treated with combination antiretroviral therapy.

    Directory of Open Access Journals (Sweden)

    Suad Kapetanovic

    Full Text Available We examined the effect of cytomegalovirus (CMV co-infection and viremia on reconstitution of selected CD4+ and CD8+ T-cell subsets in perinatally HIV-infected (PHIV+ children ≥ 1-year old who participated in a partially randomized, open-label, 96-week combination antiretroviral therapy (cART-algorithm study.Participants were categorized as CMV-naïve, CMV-positive (CMV+ viremic, and CMV+ aviremic, based on blood, urine, or throat culture, CMV IgG and DNA polymerase chain reaction measured at baseline. At weeks 0, 12, 20 and 40, T-cell subsets including naïve (CD62L+CD45RA+; CD95-CD28+, activated (CD38+HLA-DR+ and terminally differentiated (CD62L-CD45RA+; CD95+CD28- CD4+ and CD8+ T-cells were measured by flow cytometry.Of the 107 participants included in the analysis, 14% were CMV+ viremic; 49% CMV+ aviremic; 37% CMV-naïve. In longitudinal adjusted models, compared with CMV+ status, baseline CMV-naïve status was significantly associated with faster recovery of CD8+CD62L+CD45RA+% and CD8+CD95-CD28+% and faster decrease of CD8+CD95+CD28-%, independent of HIV VL response to treatment, cART regimen and baseline CD4%. Surprisingly, CMV status did not have a significant impact on longitudinal trends in CD8+CD38+HLA-DR+%. CMV status did not have a significant impact on any CD4+ T-cell subsets.In this cohort of PHIV+ children, the normalization of naïve and terminally differentiated CD8+ T-cell subsets in response to cART was detrimentally affected by the presence of CMV co-infection. These findings may have implications for adjunctive treatment strategies targeting CMV co-infection in PHIV+ children, especially those that are now adults or reaching young adulthood and may have accelerated immunologic aging, increased opportunistic infections and aging diseases of the immune system.

  11. MicroRNA 10a marks regulatory T cells

    DEFF Research Database (Denmark)

    Jeker, Lukas T; Zhou, Xuyu; Gershberg, Kseniya

    2012-01-01

    MicroRNAs (miRNAs) are crucial for regulatory T cell (Treg) stability and function. We report that microRNA-10a (miR-10a) is expressed in Tregs but not in other T cells including individual thymocyte subsets. Expression profiling in inbred mouse strains demonstrated that non-obese diabetic (NOD......) mice with a genetic susceptibility for autoimmune diabetes have lower Treg-specific miR-10a expression than C57BL/6J autoimmune resistant mice. Inhibition of miR-10a expression in vitro leads to reduced FoxP3 expression levels and miR-10a expression is lower in unstable "exFoxP3" T cells. Unstable...... and phenotype of natural Treg nor the capacity of conventional T cells to induce FoxP3 in response to TGFβ, RA, or a combination of the two. Thus, miR-10a is selectively expressed in Treg but inhibition by antagomiRs or genetic ablation resulted in discordant effects on FoxP3....

  12. T cell immunity

    OpenAIRE

    Emel Bülbül Başkan

    2013-01-01

    Since birth, our immune system is constantly bombarded with self-antigens and foreign pathogens. To stay healthy, complex immune strategies have evolved in our immune system to maintain self-tolerance and to defend against foreign pathogens. Effector T cells are the key players in steering the immune responses to execute immune functions. While effector T cells were initially identified to be immune promoting, recent studies unraveled negative regulatory functions of effector T cells...

  13. Stress assisted selective ablation of ITO thin film by picosecond laser

    Science.gov (United States)

    Farid, Nazar; Chan, Helios; Milne, David; Brunton, Adam; M. O'Connor, Gerard

    2018-01-01

    Fast selective pattering with high precession on 175 nm ITO thin film with IR ps lasers is investigated. Ablation parameters are optimized with detailed studies on the scribed depth, topography, and particle generation using AFM and SEM. A comparison of 10 and 150 ps laser revealed that the shorter pulse (10 ps) laser is more appropriate in selective and partial ablation; up to 20 nm resolution for controlled depth with multipulses having energy below the damage threshold is demonstrated. The experimental results are interpreted to involve stress assisted ablation mechanism for the 10 ps laser while thermal ablation along with intense melting occurs for 150 ps laser. The transition between these regimes is estimated to occur at approximately 30 ps.

  14. TCR tuning of T cell subsets.

    Science.gov (United States)

    Cho, Jae-Ho; Sprent, Jonathan

    2018-05-01

    After selection in the thymus, the post-thymic T cell compartments comprise heterogenous subsets of naive and memory T cells that make continuous T cell receptor (TCR) contact with self-ligands bound to major histocompatibility complex (MHC) molecules. T cell recognition of self-MHC ligands elicits covert TCR signaling and is particularly important for controlling survival of naive T cells. Such tonic TCR signaling is tightly controlled and maintains the cells in a quiescent state to avoid autoimmunity. Here, we review how naive and memory T cells are differentially tuned and wired for TCR sensitivity to self and foreign ligands. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Foxp3(+) T cells regulate immunoglobulin a selection and facilitate diversification of bacterial species responsible for immune homeostasis.

    Science.gov (United States)

    Kawamoto, Shimpei; Maruya, Mikako; Kato, Lucia M; Suda, Wataru; Atarashi, Koji; Doi, Yasuko; Tsutsui, Yumi; Qin, Hongyan; Honda, Kenya; Okada, Takaharu; Hattori, Masahira; Fagarasan, Sidonia

    2014-07-17

    Foxp3(+) T cells play a critical role for the maintenance of immune tolerance. Here we show that in mice, Foxp3(+) T cells contributed to diversification of gut microbiota, particularly of species belonging to Firmicutes. The control of indigenous bacteria by Foxp3(+) T cells involved regulatory functions both outside and inside germinal centers (GCs), consisting of suppression of inflammation and regulation of immunoglobulin A (IgA) selection in Peyer's patches, respectively. Diversified and selected IgAs contributed to maintenance of diversified and balanced microbiota, which in turn facilitated the expansion of Foxp3(+) T cells, induction of GCs, and IgA responses in the gut through a symbiotic regulatory loop. Thus, the adaptive immune system, through cellular and molecular components that are required for immune tolerance and through the diversification as well as selection of antibody repertoire, mediates host-microbial symbiosis by controlling the richness and balance of bacterial communities required for homeostasis. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Considering Angle Selection When Using Ultrasound Electrode Displacement Elastography to Evaluate Radiofrequency Ablation of Tissues

    Science.gov (United States)

    Li, Qiang; Chen, Pin-Yu; Wang, Chiao-Yin; Liu, Hao-Li; Teng, Jianfu

    2014-01-01

    Percutaneous radiofrequency ablation (RFA) is a minimally invasive treatment to thermally destroy tumors. Ultrasound-based electrode-displacement elastography is an emerging technique for evaluating the region of RFA-induced lesions. The angle between the imaging probe and the RFA electrode can influence electrode-displacement elastography when visualizing the ablation zone. We explored the angle effect on electrode-displacement elastography to measure the ablation zone. Phantoms embedded with meatballs were fabricated and then ablated using an RFA system to simulate RFA-induced lesions. For each phantom, a commercial ultrasound scanner with a 7.5 MHz linear probe was used to acquire raw image data at different angles, ranging from 30° to 90° at increments of 10°, to construct electrode-displacement images and facilitate comparisons with tissue section images. The results revealed that the ablation regions detected using electrode-displacement elastography were highly correlated with those from tissue section images when the angle was between 30° and 60°. However, the boundaries of lesions were difficult to distinguish, when the angle was larger than 60°. The experimental findings suggest that angle selection should be considered to achieve reliable electrode-displacement elastography to describe ablation zones. PMID:24971347

  17. Memory T Cell Migration

    OpenAIRE

    Qianqian eZhang; Qianqian eZhang; Fadi G. Lakkis

    2015-01-01

    Immunological memory is a key feature of adaptive immunity. It provides the organism with long-lived and robust protection against infection. In organ transplantation, memory T cells pose a significant threat by causing allograft rejection that is generally resistant to immunosuppressive therapy. Therefore, a more thorough understanding of memory T cell biology is needed to improve the survival of transplanted organs without compromising the host’s ability to fight infections. This review...

  18. An IFNG SNP with an estrogen-like response element selectively enhances promoter expression in peripheral but not lamina propria T cells.

    Science.gov (United States)

    Gonsky, R; Deem, R L; Bream, J H; Young, H A; Targan, S R

    2006-07-01

    This study examines mucosa-specific regulatory pathways involved in modulation of interferon-gamma (IFN-gamma) in lamina propria T cells. Previous studies identified mucosa-specific CD2 cis-elements within the -204 to -108 bp IFNG promoter. Within this region, a single-site nucleotide polymorphism, -179G/T, imparts tumor necrosis factor-alpha stimulation of IFNG in peripheral blood lymphocytes, and is linked with accelerated AIDS progression. We discovered a putative estrogen response element (ERE) introduced by the -179T, which displays selective activation in peripheral blood mononuclear cells (PBMC) vs lamina propria mononuclear cells (LPMC). Transfection of PBMC with constructs containing the -179G or -179T site revealed CD2-mediated enhancement of the -179T compared to -179G allele, although, in LPMC, a similar level of expression was detected. Electrophoretic mobility shift assay (EMSA) analysis demonstrated CD2-mediated nucleoprotein binding to the -179T but not the -179G in PBMC. In LPMC, binding is constitutive to both -179G and -179T regions. Sequence and EMSA analysis suggests that the -179T allele creates an ERE-like binding site capable of binding recombinant estrogen receptor. Estrogen response element transactivation is enhanced by CD2 signaling, but inhibited by estrogen in PBMC but not in LPMC, although expression of estrogen receptor was similar. This is the first report to describe a potential molecular mechanism responsible for selectively controlling IFN-gamma production in LPMC.

  19. Adaptive Immunity to Leukemia Is Inhibited by Cross-Reactive Induced Regulatory T Cells.

    Science.gov (United States)

    Manlove, Luke S; Berquam-Vrieze, Katherine E; Pauken, Kristen E; Williams, Richard T; Jenkins, Marc K; Farrar, Michael A

    2015-10-15

    BCR-ABL(+) acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific Ag that could be a target for immunotherapy. We demonstrate that the immune system can limit BCR-ABL(+) leukemia progression although ultimately this immune response fails. To address how BCR-ABL(+) leukemia escapes immune surveillance, we developed a peptide: MHC class II tetramer that labels endogenous BCR-ABL-specific CD4(+) T cells. Naive mice harbored a small population of BCR-ABL-specific T cells that proliferated modestly upon immunization. The small number of naive BCR-ABL-specific T cells was due to negative selection in the thymus, which depleted BCR-ABL-specific T cells. Consistent with this observation, we saw that BCR-ABL-specific T cells were cross-reactive with an endogenous peptide derived from ABL. Despite this cross-reactivity, the remaining population of BCR-ABL reactive T cells proliferated upon immunization with the BCR-ABL fusion peptide and adjuvant. In response to BCR-ABL(+) leukemia, BCR-ABL-specific T cells proliferated and converted into regulatory T (Treg) cells, a process that was dependent on cross-reactivity with self-antigen, TGF-β1, and MHC class II Ag presentation by leukemic cells. Treg cells were critical for leukemia progression in C57BL/6 mice, as transient Treg cell ablation led to extended survival of leukemic mice. Thus, BCR-ABL(+) leukemia actively suppresses antileukemia immune responses by converting cross-reactive leukemia-specific T cells into Treg cells. Copyright © 2015 by The American Association of Immunologists, Inc.

  20. Optical fiber biocompatible sensors for monitoring selective treatment of tumors via thermal ablation

    Science.gov (United States)

    Tosi, Daniele; Poeggel, Sven; Dinesh, Duraibabu B.; Macchi, Edoardo G.; Gallati, Mario; Braschi, Giovanni; Leen, Gabriel; Lewis, Elfed

    2015-09-01

    Thermal ablation (TA) is an interventional procedure for selective treatment of tumors, that results in low-invasive outpatient care. The lack of real-time control of TA is one of its main weaknesses. Miniature and biocompatible optical fiber sensors are applied to achieve a dense, multi-parameter monitoring, that can substantially improve the control of TA. Ex vivo measurements are reported performed on porcine liver tissue, to reproduce radiofrequency ablation of hepatocellular carcinoma. Our measurement campaign has a two-fold focus: (1) dual pressure-temperature measurement with a single probe; (2) distributed thermal measurement to estimate point-by-point cells mortality.

  1. Targeting regulatory T cells in cancer.

    LENUS (Irish Health Repository)

    Byrne, William L

    2012-01-31

    Infiltration of tumors by regulatory T cells confers growth and metastatic advantages by inhibiting antitumor immunity and by production of receptor activator of NF-kappaB (RANK) ligand, which may directly stimulate metastatic propagation of RANK-expressing cancer cells. Modulation of regulatory T cells can enhance the efficacy of cancer immunotherapy. Strategies include depletion, interference with function, inhibition of tumoral migration, and exploitation of T-cell plasticity. Problems with these strategies include a lack of specificity, resulting in depletion of antitumor effector T cells or global interruption of regulatory T cells, which may predispose to autoimmune diseases. Emerging technologies, such as RNA interference and tetramer-based targeting, may have the potential to improve selectivity and efficacy.

  2. Selective laser etching or ablation for fabrication of devices

    KAUST Repository

    Buttner, Ulrich; Salama, Khaled N.; Sapsanis, Christos

    2017-01-01

    Methods of fabricating devices vial selective laser etching are provided. The methods can include selective laser etching of a portion of a metal layer, e.g. using a laser light source having a wavelength of 1,000 nm to 1,500 nm. The methods can

  3. Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma.

    Science.gov (United States)

    Nairismägi, M -L; Gerritsen, M E; Li, Z M; Wijaya, G C; Chia, B K H; Laurensia, Y; Lim, J Q; Yeoh, K W; Yao, X S; Pang, W L; Bisconte, A; Hill, R J; Bradshaw, J M; Huang, D; Song, T L L; Ng, C C Y; Rajasegaran, V; Tang, T; Tang, Q Q; Xia, X J; Kang, T B; Teh, B T; Lim, S T; Ong, C K; Tan, J

    2018-05-01

    Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

  4. T cells in vascular inflammatory diseases

    Directory of Open Access Journals (Sweden)

    Lucas L Lintermans

    2014-10-01

    Full Text Available Inflammation of the human vasculature is a manifestation of many different diseases ranging from systemic autoimmune diseases to chronic inflammatory diseases, in which multiple types of immune cells are involved. For both autoimmune diseases and chronic inflammatory diseases several observations support a key role for T lymphocytes in these disease pathologies, but the underlying mechanisms are poorly understood. Previous studies in several autoimmune diseases have demonstrated a significant role for a specific subset of CD4+ T cells termed effector memory T cells. This expanded population of effector memory T cells may contribute to tissue injury and disease progression. These cells exert multiple pro-inflammatory functions through the release of effector cytokines. Many of these cytokines have been detected in the inflammatory lesions and participate in the vasculitic reaction, contributing to recruitment of macrophages, neutrophils, dendritic cells, NK cells, B cells and T cells. In addition, functional impairment of regulatory T cells paralyzes anti-inflammatory effects in vasculitic disorders. Interestingly, activation of effector memory T cells in uniquely dependent on the voltage-gated Kv1.3 potassium channel providing an anchor for specific drug targeting. In this review, we focus on the CD4+ T cells in the context of vascular inflammation and describe the evidence supporting the role of different T cell subsets in vascular inflammation. Selective targeting of pathogenic effector memory T cells might enable a more tailored therapeutic approach that avoids unwanted adverse side effects of generalized immunosuppression by modulating the effector functions of T cell responses to inhibit the development of vascular inflammation.

  5. In vitro selection of DNA elements highly responsive to the human T-cell lymphotropic virus type I transcriptional activator, Tax.

    Science.gov (United States)

    Paca-Uccaralertkun, S; Zhao, L J; Adya, N; Cross, J V; Cullen, B R; Boros, I M; Giam, C Z

    1994-01-01

    The human T-cell lymphotropic virus type I (HTLV-I) transactivator, Tax, the ubiquitous transcriptional factor cyclic AMP (cAMP) response element-binding protein (CREB protein), and the 21-bp repeats in the HTLV-I transcriptional enhancer form a ternary nucleoprotein complex (L. J. Zhao and C. Z. Giam, Proc. Natl. Acad. Sci. USA 89:7070-7074, 1992). Using an antibody directed against the COOH-terminal region of Tax along with purified Tax and CREB proteins, we selected DNA elements bound specifically by the Tax-CREB complex in vitro. Two distinct but related groups of sequences containing the cAMP response element (CRE) flanked by long runs of G and C residues in the 5' and 3' regions, respectively, were preferentially recognized by Tax-CREB. In contrast, CREB alone binds only to CRE motifs (GNTGACG[T/C]) without neighboring G- or C-rich sequences. The Tax-CREB-selected sequences bear a striking resemblance to the 5' or 3' two-thirds of the HTLV-I 21-bp repeats and are highly inducible by Tax. Gel electrophoretic mobility shift assays, DNA transfection, and DNase I footprinting analyses indicated that the G- and C-rich sequences flanking the CRE motif are crucial for Tax-CREB-DNA ternary complex assembly and Tax transactivation but are not in direct contact with the Tax-CREB complex. These data show that Tax recruits CREB to form a multiprotein complex that specifically recognizes the viral 21-bp repeats. The expanded DNA binding specificity of Tax-CREB and the obligatory role the ternary Tax-CREB-DNA complex plays in transactivation reveal a novel mechanism for regulating the transcriptional activity of leucine zipper proteins like CREB.

  6. Novel understanding of self-reactive T cells

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2016-01-01

    In a recent issue of Immunity, Mark Davis and colleagues describe that thymic selection does not eliminate but prunes self-reactive T cell clones. Self-reactive T cells are a natural part of the T-cell repertoire and may be important in the fight against pathogens in addition to being important...

  7. Selective laser etching or ablation for fabrication of devices

    KAUST Repository

    Buttner, Ulrich

    2017-01-12

    Methods of fabricating devices vial selective laser etching are provided. The methods can include selective laser etching of a portion of a metal layer, e.g. using a laser light source having a wavelength of 1,000 nm to 1,500 nm. The methods can be used to fabricate a variety of features, including an electrode, an interconnect, a channel, a reservoir, a contact hole, a trench, a pad, or a combination thereof. A variety of devices fabricated according to the methods are also provided. In some aspects, capacitive humidity sensors are provided that can be fabricated according to the provided methods. The capacitive humidity sensors can be fabricated with intricate electrodes, e.g. having a fractal pattern such as a Peano curve, a Hilbert curve, a Moore curve, or a combination thereof.

  8. Adoptive T cell therapy: Addressing challenges in cancer immunotherapy

    Directory of Open Access Journals (Sweden)

    Yee Cassian

    2005-04-01

    Full Text Available Abstract Adoptive T cell therapy involves the ex vivo selection and expansion of effector cells for the treatment of patients with cancer. In this review, the advantages and limitations of using antigen-specific T cells are discussed in counterpoint to vaccine strategies. Although vaccination strategies represent more readily available reagents, adoptive T cell therapy provides highly selected T cells of defined phenotype, specificity and function that may influence their biological behavior in vivo. Adoptive T cell therapy offers not only translational opportunities but also a means to address fundamental issues in the evolving field of cancer immunotherapy.

  9. Selective removal of esthetic composite restorations with spectral guided laser ablation

    Science.gov (United States)

    Yi, Ivana; Chan, Kenneth H.; Tsuji, Grant H.; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

    2016-02-01

    Dental composites are used for a wide range of applications such as fillings for cavities, adhesives for orthodontic brackets, and closure of gaps (diastemas) between teeth by esthetic bonding. Anterior restorations are used to replace missing, diseased and unsightly tooth structure for both appearance and function. When these restorations must be replaced, they are difficult to remove mechanically without causing excessive removal or damage to enamel because dental composites are color matched to teeth. Previous studies have shown that CO2 lasers have high ablation selectivity and are well suited for removal of composite on occlusal surfaces while minimizing healthy tissue loss. A spectral feedback guidance system may be used to discriminate between dental composite and dental hard tissue for selective ablation of composite material. The removal of composite restorations filling diastemas is more challenging due to the esthetic concern for anterior teeth. The objective of this study is to determine if composite spanning a diastema between anterior teeth can be removed by spectral guided laser ablation at clinically relevant rates with minimal damage to peripheral healthy tissue and with higher selectivity than a high speed dental handpiece.

  10. The efficacy of selective calculus ablation at 400 nm: comparison to conventional calculus removal methods

    Science.gov (United States)

    Schoenly, Joshua E.; Seka, Wolf; Romanos, Georgios; Rechmann, Peter

    A desired outcome of scaling and root planing is the complete removal of calculus and infected root tissue and preservation of healthy cementum for rapid healing of periodontal tissues. Conventional periodontal treatments for calculus removal, such as hand instrument scaling and ultrasonic scaling, often deeply scrape the surface of the underlying hard tissue and may leave behind a smear layer. Pulsed lasers emitting at violet wavelengths (specifically, 380 to 400 nm) are a potential alternative treatment since they can selectively ablate dental calculus without ablating pristine hard tissue (i.e., enamel, cementum, and dentin). In this study, light and scanning electron microscopy are used to compare and contrast the efficacy of in vitro calculus removal for several conventional periodontal treatments (hand instruments, ultrasonic scaler, and Er:YAG laser) to calculus removal with a frequency-doubled Ti:sapphire (λ = 400 nm). After calculus removal, enamel and cementum surfaces are investigated for calculus debris and damage to the underlying hard tissue surface. Compared to the smear layer, grooves, and unintentional hard tissue removal typically found using these conventional treatments, calculus removal using the 400-nm laser is complete and selective without any removal of pristine dental hard tissue. Based on these results, selective ablation from the 400-nm laser appears to produce a root surface that would be more suitable for successful healing of periodontal tissues.

  11. A Traceless Selection: Counter-selection System That Allows Efficient Generation of Transposon and CRISPR-modified T-cell Products

    Directory of Open Access Journals (Sweden)

    Riccardo Mezzadra

    2016-01-01

    Full Text Available Recent years have seen major breakthroughs in genome-engineering systems, such as transposon-mediated gene delivery systems and CRISPR-Cas9-mediated genome-editing tools. In these systems, transient expression of auxiliary genes is responsible for permanent genomic modification. For both systems, it would be valuable to select for cells that are likely to undergo stable genome modification. Importantly, in particular for clinical applications of genome-engineered cell products, it will also be of importance to remove those cells that, due to random vector integration, display an unwanted stable expression of the auxiliary gene. Here, we develop a traceless selection system that on the one hand allows efficient enrichment of modified cells, and on the other hand can be used to select against cells that retain expression of the auxiliary gene. The value of this system to produce highly enriched-auxiliary gene-free cell products is demonstrated.

  12. Viral dsRNA-activated human dendritic cells produce IL-27, which selectively promotes cytotoxicity in naive CD8(+) T cells

    NARCIS (Netherlands)

    de Groot, Rosa; van Beelen, Astrid J.; Bakdash, Ghaith; Taanman-Kueter, Esther W. M.; de Jong, Esther C.; Kapsenberg, Martien L.

    2012-01-01

    Viral recognition programs DCs to express Signal 3 molecules that promote the differentiation of effector CD8(+) T cells. Besides IL-12, another DC-derived IL-12 family member, IL-27, has been reported to contribute herein, but its specific role is not well understood. Here, we show that whereas

  13. Angioimmunoblastic T-Cell Lymphoma

    Science.gov (United States)

    ... Non-Hodgkin Lymphoma Peripheral T-Cell Lymphoma Primary Central Nervous System Lymphoma T-Cell Lymphoma Transformed Mycosis Fungoides Waldenstrom Macroglobulinemia Young Adult Lymphoma Overview Treatment Options Relapsed/Refractory Long-term ...

  14. Peripheral T-Cell Lymphoma

    Science.gov (United States)

    ... Non-Hodgkin Lymphoma Peripheral T-Cell Lymphoma Primary Central Nervous System Lymphoma T-Cell Lymphoma Transformed Mycosis Fungoides Waldenstrom Macroglobulinemia Young Adult Lymphoma Overview Treatment Options Relapsed/Refractory Long-term ...

  15. ONC201 selectively induces apoptosis in cutaneous T-cell lymphoma cells via activating pro-apoptotic integrated stress response and inactivating JAK/STAT and NF-κB pathways.

    Science.gov (United States)

    Ni, Xiao; Zhang, Xiang; Hu, Cheng-Hui; Langridge, Timothy; Tarapore, Rohinton S; Allen, Joshua E; Oster, Wolfgang; Duvic, Madeleine

    2017-09-22

    Cutaneous T-cell lymphomas (CTCLs) are extremely symptomatic and still incurable, and more effective and less toxic therapies are urgently needed. ONC201, an imipridone compound, has shown efficacy in pre-clinical studies in multiple advanced cancers. This study was to evaluate the anti-tumor activity of ONC201 on CTCL cells. The effect of ONC201 on the cell growth and apoptosis were evaluated in CTCL cell lines (n=8) and primary CD4 + malignant T cells isolated from CTCL patients (n=5). ONC201 showed a time-dependent cell growth inhibition in all treated cell lines with a concentration range of 1.25-10.0 μM. ONC201 also induced apoptosis in tested cells with a narrow concentration range of 2.5-10.0 μM, evidenced by increased Annexin V + cells, accompanied by accumulated sub-G1 portions. ONC201 only induced apoptosis in CD4 + malignant T cells, not in normal CD4 + T cells. The activating transcription factor 4 (ATF4), a hallmark of integrated stress response, was upregulated in response to ONC201 whereas Akt was downregulated. In addition, molecules in JAK/STAT and NF-κB pathways, as well as IL-32β, were downregulated following ONC201 treatment. Thus, ONC201 exerts a potent and selective anti-tumor effect on CTCL cells. Its efficacy may involve activating integrated stress response through ATF4 and inactivating JAK/STAT and NF-κB pathways.

  16. Dynamic frame selection for in vivo ultrasound temperature estimation during radiofrequency ablation

    International Nuclear Information System (INIS)

    Daniels, Matthew J; Varghese, Tomy

    2010-01-01

    Minimally invasive therapies such as radiofrequency ablation have been developed to treat cancers of the liver, prostate and kidney without invasive surgery. Prior work has demonstrated that ultrasound echo shifts due to temperature changes can be utilized to track the temperature distribution in real time. In this paper, a motion compensation algorithm is evaluated to reduce the impact of cardiac and respiratory motion on ultrasound-based temperature tracking methods. The algorithm dynamically selects the next suitable frame given a start frame (selected during the exhale or expiration phase where extraneous motion is reduced), enabling optimization of the computational time in addition to reducing displacement noise artifacts incurred with the estimation of smaller frame-to-frame displacements at the full frame rate. A region of interest that does not undergo ablation is selected in the first frame and the algorithm searches through subsequent frames to find a similarly located region of interest in subsequent frames, with a high value of the mean normalized cross-correlation coefficient value. In conjunction with dynamic frame selection, two different two-dimensional displacement estimation algorithms namely a block matching and multilevel cross-correlation are compared. The multi-level cross-correlation method incorporates tracking of the lateral tissue expansion in addition to the axial deformation to improve the estimation performance. Our results demonstrate the ability of the proposed motion compensation using dynamic frame selection in conjunction with the two-dimensional multilevel cross-correlation to track the temperature distribution.

  17. Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Molpeceres, C. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain)], E-mail: carlos.molpeceres@upm.es; Lauzurica, S.; Garcia-Ballesteros, J.J.; Morales, M.; Guadano, G.; Ocana, J.L. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain); Fernandez, S.; Gandia, J.J. [Dept. de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Villar, F.; Nos, O.; Bertomeu, J. [CeRMAE Dept. Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)

    2009-03-15

    Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

  18. Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

    International Nuclear Information System (INIS)

    Molpeceres, C.; Lauzurica, S.; Garcia-Ballesteros, J.J.; Morales, M.; Guadano, G.; Ocana, J.L.; Fernandez, S.; Gandia, J.J.; Villar, F.; Nos, O.; Bertomeu, J.

    2009-01-01

    Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

  19. Engineering CAR-T cells.

    Science.gov (United States)

    Zhang, Cheng; Liu, Jun; Zhong, Jiang F; Zhang, Xi

    2017-01-01

    Chimeric antigen receptor redirected T cells (CAR-T cells) have achieved inspiring outcomes in patients with B cell malignancies, and are now being investigated in other hematologic malignancies and solid tumors. CAR-T cells are generated by the T cells from patients' or donors' blood. After the T cells are expanded and genetically modified, they are reinfused into the patients. However, many challenges still need to be resolved in order for this technology to gain widespread adoption. In this review, we first discuss the structure and evolution of chimeric antigen receptors. We then report on the tools used for production of CAR-T cells. Finally, we address the challenges posed by CAR-T cells.

  20. Selective ex-vivo photothermal ablation of human pancreatic cancer with albumin functionalized multiwalled carbon nanotubes.

    Science.gov (United States)

    Mocan, Lucian; Tabaran, Flaviu A; Mocan, Teodora; Bele, Constantin; Orza, Anamaria Ioana; Lucan, Ciprian; Stiufiuc, Rares; Manaila, Ioana; Iulia, Ferencz; Dana, Iancu; Zaharie, Florin; Osian, Gelu; Vlad, Liviu; Iancu, Cornel

    2011-01-01

    The process of laser-mediated ablation of cancer cells marked with biofunctionalized carbon nanotubes is frequently called "nanophotothermolysis". We herein present a method of selective nanophotothermolisys of pancreatic cancer (PC) using multiwalled carbon nanotubes (MWCNTs) functionalized with human serum albumin (HSA). With the purpose of testing the therapeutic value of these nanobioconjugates, we have developed an ex-vivo experimental platform. Surgically resected specimens from patients with PC were preserved in a cold medium and kept alive via intra-arterial perfusion. Additionally, the HSA-MWCNTs have been intra-arterially administered in the greater pancreatic artery under ultrasound guidance. Confocal and transmission electron microscopy combined with immunohistochemical staining have confirmed the selective accumulation of HSA-MWCNTs inside the human PC tissue. The external laser irradiation of the specimen has significantly produced extensive necrosis of the malign tissue after the intra-arterial administration of HSA-MWCNTs, without any harmful effects on the surrounding healthy parenchyma. We have obtained a selective photothermal ablation of the malign tissue based on the selective internalization of MWCNTs with HSA cargo inside the pancreatic adenocarcinoma after the ex-vivo intra-arterial perfusion.

  1. Neoantigen landscape dynamics during human melanoma-T cell interactions

    DEFF Research Database (Denmark)

    Verdegaal, Els M. E.; De Miranda, Noel F. C. C.; Visser, Marten

    2016-01-01

    Recognition of neoantigens that are formed as a consequence of DNA damage is likely to form a major driving force behind the clinical activity of cancer immunotherapies such as T-cell checkpoint blockade and adoptive T-cell therapy. Therefore, strategies to selectively enhance T-cell reactivity...... against genetically defined neoantigens are currently under development. In mouse models, T-cell pressure can sculpt the antigenicity of tumours, resulting in the emergence of tumours that lack defined mutant antigens. However, whether the T-cell-recognized neoantigen repertoire in human cancers...... by overall reduced expression of the genes or loss of the mutant alleles. Notably, loss of expression of T-cell-recognized neoantigens was accompanied by development of neoantigen-specific T-cell reactivity in tumour-infiltrating lymphocytes. These data demonstrate the dynamic interactions between cancer...

  2. Selective amplification of T-cell receptor variable region species is demonstrable but not essential in early lesions of psoriasis vulgaris: analysis by anchored polymerase chain reaction and hypervariable region size spectratyping.

    Science.gov (United States)

    Vekony, M A; Holder, J E; Lee, A J; Horrocks, C; Eperon, I C; Camp, R D

    1997-07-01

    Several groups have investigated the role of T cells in the pathogenesis of psoriasis by determination of T-cell receptor (TCR) B-chain variable (V) region usage, both in chronic plaque (psoriasis vulgaris) and guttate forms, with various results. Because there are no data on TCR expression in early psoriasis vulgaris, when specific cellular immune events may be expected to be most pronounced, we have analyzed early lesions (less than 3 wk old) of ten patients, with highly reproducible results. We have developed a highly controlled anchored polymerase chain reaction (PCR) method in which TCR beta chain species are all amplified with the same primer pair and products are quantified by dot blot hybridization with BV family-specific oligonucleotide probes. Overexpression of certain TCR BV genes was observed in the majority of lesional biopsies, but in samples in which the expanded BV family formed more than 10% of total lesional BV (half of the samples analyzed), BV2 and BV6 predominated. The consistency of overexpression of these BV species between patients was much less than in previous studies of TCRBV usage in established chronic plaque psoriasis lesions. Complementarity-determining region 3 (CDR3) size spectratyping demonstrated evidence for selective clonal T cell accumulation in less than half of the lesional samples showing BV expansion. These results indicate that selective amplification of TCRBV species occurs in early psoriasis vulgaris but is not essential to the pathogenic process and may be more important in the maintenance or expansion of chronic lesions.

  3. Intrathymic selection of NK1.1+α/β T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad

    OpenAIRE

    Iwabuchi, Chikako; Iwabuchi, Kazuya; Nakagawa, Ken-ichi; Takayanagi, Toshiaki; Nishihori, Hiroki; Tone, Saori; Ogasawara, Kazumasa; Good, Robert A.; Onoé, Kazunori

    1998-01-01

    Generation and negative selection of NK1.1+α/β T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice and Rag-1−/−/DO10 mice, which had been established by breeding and backcrossing between Rag-1−/− and DO10 mice. Almost all T cells from these mice were shown to bear Vα13/Vβ8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1+ Vα13/Vβ8.2+ thymocytes was generated in these mice. Ho...

  4. CCL22-specific T Cells

    DEFF Research Database (Denmark)

    Martinenaite, Evelina; Munir Ahmad, Shamaila; Hansen, Morten

    2016-01-01

    Tumor cells and tumor-infiltrating macrophages produce the chemokine CCL22, which attracts regulatory T cells (Tregs) into the tumor microenvironment, decreasing anticancer immunity. Here, we investigated the possibility of targeting CCL22-expressing cells by activating specific T cells. We...... analyzed the CCL22 protein signal sequence, identifying a human leukocyte antigen A2- (HLA-A2-) restricted peptide epitope, which we then used to stimulate peripheral blood mononuclear cells (PMBCs) to expand populations of CCL22-specific T cells in vitro. T cells recognizing an epitope derived from...... the signal-peptide of CCL22 will recognize CCL22-expressing cells even though CCL22 is secreted out of the cell. CCL22-specific T cells recognized and killed CCL22-expressing cancer cells. Furthermore, CCL22-specific T cells lysed acute monocytic leukemia cells in a CCL22 expression-dependent manner. Using...

  5. Bioinformatics Tools for the Prediction of T-Cell Epitopes

    DEFF Research Database (Denmark)

    Andreatta, Massimo; Nielsen, Morten

    2018-01-01

    T-cell responses are activated by specific peptides, called epitopes, presented on the cell surface by MHC molecules. Binding of peptides to the MHC is the most selective step in T-cell antigen presentation and therefore an essential factor in the selection of potential epitopes. Several in-vitro...

  6. Regulatory T-cells and autoimmunity.

    LENUS (Irish Health Repository)

    Ni Choileain, Niamh

    2012-02-03

    Approximately 20% of the population is affected by autoimmune or inflammatory diseases mediated by an abnormal immune response. A characteristic feature of autoimmune disease is the selective targeting of a single cell type, organ or tissue by certain populations of autoreactive T-cells. Examples of such diseases include rheumatoid arthritis, insulin-dependent diabetes mellitus, and systemic lupus erythematosus (SLE), all of which are characterized by chronic inflammation, tissue destruction and target organ malfunction. Although strong evidence links most autoimmune diseases to specific genes, considerable controversy prevails regarding the role of regulatory T-cell populations in the disease process. These cells are now also believed to play a key role in mediating transplantation tolerance and inhibiting the induction of tumor immunity. Though the concept of therapeutic immune regulation aimed at treating autoimmune pathology has been validated in many animal models, the development of strategies for the treatment of human autoimmune disorders remains in its infancy. The main obstacles to this include the conflicting findings of different model systems, as well as the contrasting functions of regulatory T-cells and cytokines involved in the development of such disorders. This review examines the role of regulatory T-cells in the pathogenesis of autoimmunity and describes the therapeutic potential of these cells for the prevention of immune-mediated pathologies in the future. Although much remains to be learned about such pathologies, a clearer understanding of the mechanisms by which regulatory T-cells function will undoubtedly lead to exciting new possibilities for immunotherapeutics.

  7. T cell receptor-engineered T cells to treat solid tumors: T cell processing toward optimal T cell fitness

    NARCIS (Netherlands)

    C.H.J. Lamers (Cor); S. van Steenbergen-Langeveld (Sabine); M. van Brakel (Mandy); C.M. Groot-van Ruijven (Corrien); P.M.M.L. van Elzakker (Pascal); B.A. van Krimpen (Brigitte); S. Sleijfer (Stefan); J.E.M.A. Debets (Reno)

    2014-01-01

    textabstractTherapy with autologous T cells that have been gene-engineered to express chimeric antigen receptors (CAR) or T cell receptors (TCR) provides a feasible and broadly applicable treatment for cancer patients. In a clinical study in advanced renal cell carcinoma (RCC) patients with CAR T

  8. Selective ex-vivo photothermal ablation of human pancreatic cancer with albumin functionalized multiwalled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Mocan L

    2011-04-01

    Full Text Available Lucian Mocan1, Flaviu A Tabaran2, Teodora Mocan1, Constantin Bele3, Anamaria Ioana Orza1, Ciprian Lucan4, Rares Stiufiuc1, Ioana Manaila1, Ferencz Iulia1, Iancu Dana1, Florin Zaharie1, Gelu Osian1, Liviu Vlad1, Cornel Iancu11Department of Nanomedicine, “Iuliu Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, Romania; 2Department of Pathology, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania; 3Department of Biochemistry, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania; 4Clinical Institute of Urology and Renal Transplantation, Cluj-Napoca, RomaniaAbstract: The process of laser-mediated ablation of cancer cells marked with biofunctionalized carbon nanotubes is frequently called “nanophotothermolysis”. We herein present a method of selective nanophotothermolisys of pancreatic cancer (PC using multiwalled carbon nanotubes (MWCNTs functionalized with human serum albumin (HSA. With the purpose of testing the therapeutic value of these nanobioconjugates, we have developed an ex-vivo experimental platform. Surgically resected specimens from patients with PC were preserved in a cold medium and kept alive via intra-arterial perfusion. Additionally, the HSA-MWCNTs have been intra-arterially administered in the greater pancreatic artery under ultrasound guidance. Confocal and transmission electron microscopy combined with immunohistochemical staining have confirmed the selective accumulation of HSA-MWCNTs inside the human PC tissue. The external laser irradiation of the specimen has significantly produced extensive necrosis of the malign tissue after the intra-arterial administration of HSA-MWCNTs, without any harmful effects on the surrounding healthy parenchyma. We have obtained a selective photothermal ablation of the malign tissue based on the selective internalization of MWCNTs with HSA cargo inside the pancreatic adenocarcinoma after the ex-vivo intra

  9. Selective ablation of a titanium nitride film on tungsten carbide substrate using ultrashort laser pulses

    International Nuclear Information System (INIS)

    Oliveira, Eduardo Spinelli

    2017-01-01

    Surface coatings are applied to many cutting tools in the metallurgical industry in order to improve cutting efficiency and extend its useful life. In this work, tests were performed to remove the coating of titanium aluminum nitride (TiAlN) on tungsten carbide (WC-Co) pellets, using an ultrashort laser pulses beam. After determination of the damage thresholds of the film and the substrate, were ablated on the surface of the coating lines using two ablation conditions, it was initially operated on the low fluence regime for the film, and later on the low fluence regime of the substrate, far below the threshold of the film, applying high overlapping pulses. A laser induced breakdown spectroscopy (LIBS) system was set up to monitor the materials present in the plasma generated by the laser, but the system did not present sufficient sensitivity to read the low intensity of the plasma generated in the process and was not used. After the analysis of the traces by electron microscopy, optical profilometer and X-ray fluorescence spectroscopy, it was not possible to determine a safe process to carry out the selective removal of the film in question, however, due to the data obtained and observations of the results in some traces, new possibilities were raised, opening the discussion for future work. (author)

  10. CD4 T cell autophagy is integral to memory maintenance.

    Science.gov (United States)

    Murera, Diane; Arbogast, Florent; Arnold, Johan; Bouis, Delphine; Muller, Sylviane; Gros, Frédéric

    2018-04-13

    Studies of mice deficient for autophagy in T cells since thymic development, concluded that autophagy is integral to mature T cell homeostasis. Basal survival and functional impairments in vivo, limited the use of these models to delineate the role of autophagy during the immune response. We generated Atg5 f/f distal Lck (dLck)-cre mice, with deletion of autophagy only at a mature stage. In this model, autophagy deficiency impacts CD8 + T cell survival but has no influence on CD4 + T cell number and short-term activation. Moreover, autophagy in T cells is dispensable during early humoral response but critical for long-term antibody production. Autophagy in CD4 + T cells is required to transfer humoral memory as shown by injection of antigen-experienced cells in naive mice. We also observed a selection of autophagy-competent cells in the CD4 + T cell memory compartment. We performed in vitro differentiation of memory CD4 + T cells, to better characterize autophagy-deficient memory cells. We identified mitochondrial and lipid load defects in differentiated memory CD4 + T cells, together with a compromised survival, without any collapse of energy production. We then propose that memory CD4 + T cells rely on autophagy for their survival to regulate toxic effects of mitochondrial activity and lipid overload.

  11. Effect of Natalizumab on Circulating CD4(+) T-Cells in Multiple Sclerosis

    DEFF Research Database (Denmark)

    Börnsen, Lars; Christensen, Jeppe Romme; Ratzer, Rikke

    2012-01-01

    in general or myelin-reactive T-cells in particular showed signs of increased immune activation. Furthermore we examined the effects of natalizumab on CD4(+) T-cell responses to myelin in vitro. Natalizumab-treated MS patients had significantly increased numbers of effector-memory T-cells in the blood. In T-cells......(HIGH) T-cells, in blood, and natalizumab decreased the expression of CD134 on MBP-reactive CD26(HIGH)CD4(+) T-cells in vitro. Otherwise CD4(+) T-cells from natalizumab-treated and untreated MS patients showed similar responses to MBP. In conclusion natalizumab treatment selectively increased...... transmigration of circulating immune-cells across the vascular endothelium into the CNS. Recent studies suggested that natalizumab treated MS patients have an increased T-cell pool in the blood compartment which may be selectively enriched in activated T-cells. Proposed causes are sequestration of activated T-cells...

  12. Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy

    International Nuclear Information System (INIS)

    Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke; Hirobe, Sachiko; Nakagawa, Shinsaku; Okada, Naoki

    2016-01-01

    Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period of pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. - Highlights: • We established highly efficient gene transduction protocols for murine T cells. • CD8"+ CAR-T cells had antigen-specific cytotoxic activity. • CD4"+ CAR-T cells secreted multiple cytokines by antigen stimulation. • This finding can contribute to the development of T-cell biology and immunotherapy.

  13. Highly efficient gene transfer using a retroviral vector into murine T cells for preclinical chimeric antigen receptor-expressing T cell therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kusabuka, Hotaka; Fujiwara, Kento; Tokunaga, Yusuke; Hirobe, Sachiko; Nakagawa, Shinsaku, E-mail: nakagawa@phs.osaka-u.ac.jp; Okada, Naoki, E-mail: okada@phs.osaka-u.ac.jp

    2016-04-22

    Adoptive immunotherapy using chimeric antigen receptor-expressing T (CAR-T) cells has attracted attention as an efficacious strategy for cancer treatment. To prove the efficacy and safety of CAR-T cell therapy, the elucidation of immunological mechanisms underlying it in mice is required. Although a retroviral vector (Rv) is mainly used for the introduction of CAR to murine T cells, gene transduction efficiency is generally less than 50%. The low transduction efficiency causes poor precision in the functional analysis of CAR-T cells. We attempted to improve the Rv gene transduction protocol to more efficiently generate functional CAR-T cells by optimizing the period of pre-cultivation and antibody stimulation. In the improved protocol, gene transduction efficiency to murine T cells was more than 90%. In addition, almost all of the prepared murine T cells expressed CAR after puromycin selection. These CAR-T cells had antigen-specific cytotoxic activity and secreted multiple cytokines by antigen stimulation. We believe that our optimized gene transduction protocol for murine T cells contributes to the advancement of T cell biology and development of immunotherapy using genetically engineered T cells. - Highlights: • We established highly efficient gene transduction protocols for murine T cells. • CD8{sup +} CAR-T cells had antigen-specific cytotoxic activity. • CD4{sup +} CAR-T cells secreted multiple cytokines by antigen stimulation. • This finding can contribute to the development of T-cell biology and immunotherapy.

  14. Self-reactive T cells

    DEFF Research Database (Denmark)

    Becker, Jürgen C; thor Straten, Per; Andersen, Mads Hald

    2014-01-01

    -proteins expressed in regulatory immune cells have been reported, especially in patients with cancer. The seemingly lack of tolerance toward such proteins is interesting, as it suggests a regulatory function of self-reactive T (srT) cells, which may be important for the fine tuning of the immune system......The immune system is a tightly regulated and complex system. An important part of this immune regulation is the assurance of tolerance toward self-antigens to maintain immune homeostasis. However, in recent years, antigen-specific cellular immune responses toward several normal self....... In particular, surprising has been the description of cytotoxic srT cells that are able to eliminate normal regulatory immune cells. Such srT cells may be important as effector cells that suppress regulatory suppressor cells. The current knowledge of the nature and function of srT cells is still limited. Still...

  15. Evidence for mouse Th1- and Th2-like helper T cells in vivo. Selective reduction of Th1-like cells after total lymphoid irradiation

    International Nuclear Information System (INIS)

    Bass, H.; Mosmann, T.; Strober, S.

    1989-01-01

    Purified CD4+ BALB/c spleen T cells obtained 4-6 wk after total lymphoid irradiation (TLI) helped normal syngeneic B cells to produce a vigorous antibody response to TNP keyhole limpet hemocyanin in adoptive cell transfer experiments. However, the same cells failed to transfer delayed-type hypersensitivity to the adoptive hosts as measured by a foot pad swelling assay. In addition, purified CD4+ cells from TLI-treated mice were unable to induce graft vs. host disease in lethally irradiated allogeneic C57BL/Ka recipient mice. In response to mitogen stimulation, unfractionated spleen cells obtained from TLI mice secreted normal levels of IL-4 and IL-5, but markedly reduced levels of IL-2 and INF-gamma. A total of 229 CD4+ clones from spleen cells of both normal and TLI-treated mice were established, and the cytokine secretion pattern from each clone was analyzed. The results demonstrate that the ratio of Th1- and Th2-like clones in the spleens of normal BALB/c mice is 1:0.6, whereas the ratio in TLI mice is approximately 1:7. These results suggest that Th2-like cells recover rapidly (at approximately 4-6 wk) after TLI treatment and account for the early return of antibody helper activity and secretion of IL-4 and IL-5, but Th1-like cells recover more slowly (in approximately 3 mo) after irradiation, and this accounts for the deficit in cell-mediated immunity and the reduced amount of IL-2 and IFN-gamma secretion

  16. Asymmetric cell division during T cell development controls downstream fate

    Science.gov (United States)

    Pham, Kim; Shimoni, Raz; Charnley, Mirren; Ludford-Menting, Mandy J.; Hawkins, Edwin D.; Ramsbottom, Kelly; Oliaro, Jane; Izon, David; Ting, Stephen B.; Reynolds, Joseph; Lythe, Grant; Molina-Paris, Carmen; Melichar, Heather; Robey, Ellen; Humbert, Patrick O.; Gu, Min

    2015-01-01

    During mammalian T cell development, the requirement for expansion of many individual T cell clones, rather than merely expansion of the entire T cell population, suggests a possible role for asymmetric cell division (ACD). We show that ACD of developing T cells controls cell fate through differential inheritance of cell fate determinants Numb and α-Adaptin. ACD occurs specifically during the β-selection stage of T cell development, and subsequent divisions are predominantly symmetric. ACD is controlled by interaction with stromal cells and chemokine receptor signaling and uses a conserved network of polarity regulators. The disruption of polarity by deletion of the polarity regulator, Scribble, or the altered inheritance of fate determinants impacts subsequent fate decisions to influence the numbers of DN4 cells arising after the β-selection checkpoint. These findings indicate that ACD enables the thymic microenvironment to orchestrate fate decisions related to differentiation and self-renewal. PMID:26370500

  17. CAR T cell therapy for breast cancer: harnessing the tumor milieu to drive T cell activation.

    Science.gov (United States)

    Bajgain, Pradip; Tawinwung, Supannikar; D'Elia, Lindsey; Sukumaran, Sujita; Watanabe, Norihiro; Hoyos, Valentina; Lulla, Premal; Brenner, Malcolm K; Leen, Ann M; Vera, Juan F

    2018-05-10

    The adoptive transfer of T cells redirected to tumor via chimeric antigen receptors (CARs) has produced clinical benefits for the treatment of hematologic diseases. To extend this approach to breast cancer, we generated CAR T cells directed against mucin1 (MUC1), an aberrantly glycosylated neoantigen that is overexpressed by malignant cells and whose expression has been correlated with poor prognosis. Furthermore, to protect our tumor-targeted cells from the elevated levels of immune-inhibitory cytokines present in the tumor milieu, we co-expressed an inverted cytokine receptor linking the IL4 receptor exodomain with the IL7 receptor endodomain (4/7ICR) in order to transform the suppressive IL4 signal into one that would enhance the anti-tumor effects of our CAR T cells at the tumor site. First (1G - CD3ζ) and second generation (2G - 41BB.CD3ζ) MUC1-specific CARs were constructed using the HMFG2 scFv. Following retroviral transduction transgenic expression of the CAR±ICR was assessed by flow cytometry. In vitro CAR/ICR T cell function was measured by assessing cell proliferation and short- and long-term cytotoxic activity using MUC1+ MDA MB 468 cells as targets. In vivo anti-tumor activity was assessed using IL4-producing MDA MB 468 tumor-bearing mice using calipers to assess tumor volume and bioluminescence imaging to track T cells. In the IL4-rich tumor milieu, 1G CAR.MUC1 T cells failed to expand or kill MUC1+ tumors and while co-expression of the 4/7ICR promoted T cell expansion, in the absence of co-stimulatory signals the outgrowing cells exhibited an exhausted phenotype characterized by PD-1 and TIM3 upregulation and failed to control tumor growth. However, by co-expressing 2G CAR.MUC1 (signal 1 - activation + signal 2 - co-stimulation) and 4/7ICR (signal 3 - cytokine), transgenic T cells selectively expanded at the tumor site and produced potent and durable tumor control in vitro and in vivo. Our findings demonstrate the feasibility of targeting breast

  18. Contribution of herpesvirus specific CD8 T cells to anti-viral T cell response in humans.

    Directory of Open Access Journals (Sweden)

    Elena Sandalova

    Full Text Available Herpesviruses infect most humans. Their infections can be associated with pathological conditions and significant changes in T cell repertoire but evidences of symbiotic effects of herpesvirus latency have never been demonstrated. We tested the hypothesis that HCMV and EBV-specific CD8 T cells contribute to the heterologous anti-viral immune response. Volume of activated/proliferating virus-specific and total CD8 T cells was evaluated in 50 patients with acute viral infections: 20 with HBV, 12 with Dengue, 12 with Influenza, 3 with Adenovirus infection and 3 with fevers of unknown etiology. Virus-specific (EBV, HCMV, Influenza pentamer+ and total CD8 T cells were analyzed for activation (CD38/HLA-DR, proliferation (Ki-67/Bcl-2(low and cytokine production. We observed that all acute viral infections trigger an expansion of activated/proliferating CD8 T cells, which differs in size depending on the infection but is invariably inflated by CD8 T cells specific for persistent herpesviruses (HCMV/EBV. CD8 T cells specific for other non-related non persistent viral infection (i.e. Influenza were not activated. IL-15, which is produced during acute viral infections, is the likely contributing mechanism driving the selective activation of herpesvirus specific CD8 T cells. In addition we were able to show that herpesvirus specific CD8 T cells displayed an increased ability to produce the anti-viral cytokine interferon-gamma during the acute phase of heterologous viral infection. Taken together, these data demonstrated that activated herpesvirus specific CD8 T cells inflate the activated/proliferating CD8 T cells population present during acute viral infections in human and can contribute to the heterologous anti-viral T cell response.

  19. Expression of inhibitory receptors on intratumoral T cells modulates the activity of a T cell-bispecific antibody targeting folate receptor

    OpenAIRE

    Schreiner, Jens; Thommen, Daniela S.; Herzig, Petra; Bacac, Marina; Klein, Christian; Roller, Andreas; Belousov, Anton; Levitsky, Victor; Savic, Spasenija; Moersig, Wolfgang; Uhlenbrock, Franziska; Heinzelmann-Schwarz, Viola A.; Umana, Pablo; Pisa, Pavel; Lardinois, Didier

    2015-01-01

    T-cell bispecific antibodies (TCBs) are a novel therapeutic tool designed to selectively recruit T-cells to tumor cells and simultaneously activate them. However, it is currently unknown whether the dysfunctional state of T-cells, embedded into the tumor microenvironment, imprints on the therapeutic activity of TCBs. We performed a comprehensive analysis of activation and effector functions of tumor-infiltrating T-cells (TILs) in different tumor types, upon stimulation by a TCB targeting fola...

  20. Intrathymic selection of NK1.1+α/β T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad

    Science.gov (United States)

    Iwabuchi, Chikako; Iwabuchi, Kazuya; Nakagawa, Ken-ichi; Takayanagi, Toshiaki; Nishihori, Hiroki; Tone, Saori; Ogasawara, Kazumasa; Good, Robert A.; Onoé, Kazunori

    1998-01-01

    Generation and negative selection of NK1.1+α/β T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice and Rag-1−/−/DO10 mice, which had been established by breeding and backcrossing between Rag-1−/− and DO10 mice. Almost all T cells from these mice were shown to bear Vα13/Vβ8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1+ Vα13/Vβ8.2+ thymocytes was generated in these mice. However, the actual cell number of both NK1.1+ and NK1.1− thymocytes in I-Ad/d mice (positive selecting background) was larger than that in I-Ab/d mice (negative selecting background). Markedly low but significant proportions of NK1.1+ Vα13/Vβ8.2+ cells were detected in the spleens from I-Ad/d and I-Ab/d mice. It was shown that the splenic NK1.1+ T cells of the I-Ab/d mice were anergized against stimulation through TCR. When (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice were given cOVA, extensive or intermediate elimination of NK1.1+α/βTCR+ thymocytes was induced in I-Ad/d or I-Ab/d mice, respectively. However, the clonal elimination was not as complete as that seen in the major NK1.1− thymocyte population. The present findings indicate that normal generation of NK1.1+α/βTCR+ thymocytes occurs in the absence of Vα14-Jα281 and that substantial negative selection operates on the NK1.1+α/βTCR+ cells. PMID:9653164

  1. Distinct Biomarker Profiles in Ex Vivo T Cell Depletion Graft Manipulation Strategies: CD34+ Selection versus CD3+/19+ Depletion in Matched Sibling Allogeneic Peripheral Blood Stem Cell Transplantation.

    Science.gov (United States)

    Cantilena, Caroline R; Ito, Sawa; Tian, Xin; Jain, Prachi; Chinian, Fariba; Anandi, Prathima; Keyvanfar, Keyvan; Draper, Debbie; Koklanaris, Eleftheria; Hauffe, Sara; Superata, Jeanine; Stroncek, David; Muranski, Pawel; Barrett, A John; Battiwalla, Minoo

    2018-03-01

    Various approaches have been developed for ex vivo T cell depletion in allogeneic stem cell transplantation to prevent graft-versus-host disease (GVHD). Direct comparisons of T cell depletion strategies have not been well studied, however. We evaluated cellular and plasma biomarkers in 2 different graft manipulation strategies, CD3 + CD19 + cell depletion (CD3/19D) versus CD34 + selection (CD34S), and their associations with clinical outcomes. Identical conditions, including the myeloablative preparative regimen, HLA-identical sibling donor, GVHD prophylaxis, and graft source, were used in the 2 cohorts. Major clinical outcomes were similar in the 2 groups in terms of overall survival, nonrelapse mortality, and cumulative incidence of relapse; however, the cumulative incidence of acute GVHD trended to be higher in the CD3/19D cohort compared with the CD34S cohort. A distinct biomarker profile was noted in the CD3/19D cohort: higher levels of ST2, impaired Helios - FoxP3 + Treg reconstitution, and rapid reconstitution of naïve, Th2, and Th17 CD4 cells in the early post-transplantation period. In vitro graft replication studies confirmed that CD3/19D disproportionately depleted Tregs and other CD4 subset repertoires in the graft. This study confirms the utility of biomarker monitoring, which can be directly correlated with biological consequences and possible future therapeutic indications. Published by Elsevier Inc.

  2. Anti-regulatory T cells

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2017-01-01

    responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells—termed anti-regulatory T cells (anti-Tregs)—that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune...... reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells......Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host...

  3. Chemokine receptor expression by inflammatory T cells in EAE

    DEFF Research Database (Denmark)

    Mony, Jyothi Thyagabhavan; Khorooshi, Reza; Owens, Trevor

    2014-01-01

    Chemokines direct cellular infiltration to tissues, and their receptors and signaling pathways represent targets for therapy in diseases such as multiple sclerosis (MS). The chemokine CCL20 is expressed in choroid plexus, a site of entry of T cells to the central nervous system (CNS). The CCL20...... receptor CCR6 has been reported to be selectively expressed by CD4(+) T cells that produce the cytokine IL-17 (Th17 cells). Th17 cells and interferon-gamma (IFNγ)-producing Th1 cells are implicated in induction of MS and its animal model experimental autoimmune encephalomyelitis (EAE). We have assessed...... whether CCR6 identifies specific inflammatory T cell subsets in EAE. Our approach was to induce EAE, and then examine chemokine receptor expression by cytokine-producing T cells sorted from CNS at peak disease. About 7% of CNS-infiltrating CD4(+) T cells produced IFNγ in flow cytometric cytokine assays...

  4. Rag Deletion in Peripheral T Cells Blocks TCR Revision

    Science.gov (United States)

    Hale, J. Scott; Ames, Kristina T.; Boursalian, Tamar E.; Fink, Pamela J.

    2010-01-01

    Mature CD4+Vβ5+ T cells that recognize a peripherally expressed endogenous superantigen are tolerized either by deletion or T cell receptor (TCR) revision. In Vβ5 transgenic mice, this latter tolerance pathway results in the appearance of CD4+Vβ5−TCRβ+ T cells, coinciding with Rag1, Rag2, and TdT expression and the accumulation of Vβ-DJβ recombination intermediates in peripheral CD4+ T cells. Because post-thymic RAG-dependent TCR rearrangement has remained controversial, we sought to definitively determine whether TCR revision is an extrathymic process that occurs in mature peripheral T cells. We now show that Rag deletion in post-positive selection T cells in Vβ5 transgenic mice blocks TCR revision in vivo, and that mature peripheral T cells sorted to remove cells bearing endogenous TCRβ chains can express newly generated TCRβ molecules in adoptive hosts. These findings unambiguously demonstrate post-thymic, RAG-dependent TCR rearrangement and define TCR revision as a tolerance pathway that targets mature peripheral CD4+ T cells. PMID:20435935

  5. Possible neuroimmunomodulation therapy in T-cell-mediated oral diseases

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Sato

    2015-01-01

    Full Text Available Introduction: Recurrent aphthous stomatitis and oral lichen planus are local chronic inflammatory diseases which are implicated in T cell-mediated immunity. According to the systematic review, there is insufficient evidence to support any specific treatment for T-cell mediated oral diseases. The hypothesis: In this paper, we propose a hypothesis that recurrent aphthous stomatitis and oral lichen planus can be treated with selective α7 subunit of nicotinic acetylcholine receptor (α7 -nAChR agonists. Our hypothesis is supported by the following two facts. First, the pathophysiological conditions, T h 1/T h 17 cell activation and autonomic nervous system dysfunction, are observed in T-cell mediated oral diseases as well as in T-cell mediated systemic diseases such as rheumatoid arthritis. Second, the cholinergic anti-inflammatory pathway is inhibited in systemic T-cell mediated chronic inflammatory diseases. On the other hand, treatment with α7 -nAChR agonists which activate the cholinergic anti-inflammatory pathway suppresses neuroinflammation via inhibition of T h 1/T h 17 responses in animal model of systemic T-cell mediated chronic inflammatory diseases. We thus expect that selective α7 -nAChR agonists will be effective for the treatment of T-cell mediated oral diseases. Evaluation of the hypothesis: To test our hypothesis, we need to develop in vivo mouse model of T-cell mediated oral diseases. To evaluate the therapeutic effect of a selective α7 -nAChR agonist, we choose ABT-107 because of its safety and tolerability. We believe that the selective α7 -nAChR agonist, especially ABT-107, may be a therapeutic drug to treat T-cell mediated oral diseases.

  6. Selective near-UV ablation of subgingival dental calculus: measurement of removal rates

    Science.gov (United States)

    Schoenly, J. E.; Seka, W.; Rechmann, P.

    2010-02-01

    A noncontact profilometer (laser triangulation) was used to measure the removal rates of subgingival dental calculus irradiated with a frequency-doubled Ti:sapphire laser (60-ns pulse duration, 400-nm wavelength, 10-Hz repetition rate, 7-mJ pulse energy). Profilometer traces before and after irradiation were used to create a removal map with 4-μm axial and 15-μm transverse resolution. Twenty-three teeth (15 with calculus and 8 pristine) were irradiated at 90° and 45° under a cooling water spray with a super-Gaussian beam (~300-μm diameter). Subgingival calculus was selectively removed at 5.6 and 4.0 J/cm2 for 90° and 45°, respecetively, within a range of rates, between 2 to 9 μm/pulse. These ablation rates were constant during these exposures. For comparison, pristine cementum irradiated for 10 min at the same peak fluence and pulse repetition rate showed only craters, 15 to 50 μm deep, corresponding to an equivalent removal rate three orders of magnitude smaller than that obtained for calculus. Pristine enamel was not removed under the same irradiation conditions.

  7. Useful clinical features for the selection of ideal patients with strial fibrillation for mapping and catheter ablation

    Directory of Open Access Journals (Sweden)

    Mehta Niraj

    2002-01-01

    Full Text Available OBJECTIVE: To identify useful clinical characteristics for selecting patients eligible for mapping and ablation of atrial fibrillation. METHODS: We studied 9 patients with atrial fibrillation, without structural heart disease, associated with: 1 antiarrhythmic drugs, 2 symptoms of low cardiac output, and 3 intention to treat. Seven patients had paroxysmal atrial fibrillation and 2 had recurrent atrial fibrillation. RESULTS: In the 6 patients who underwent mapping (all had paroxysmal atrial fibrillation, catheter ablation was successfully carried out in superior pulmonary veins in 5 patients (the first 3 in the left superior pulmonary vein and the last 2 in the right superior pulmonary vein. One patient experienced a recurrence of atrial fibrillation after 10 days. We observed that patients who had short episodes of atrial fibrillation on 24-hour Holter monitoring before the procedure were those in whom mapping the focus of tachycardia was possible. Tachycardia was successfully suppressed in 4 of 6 patients. The cause of failure was due to the impossibility of maintaining sinus rhythm long enough for efficient mapping. CONCLUSION: Patients experiencing short episodes of atrial fibrillation during 24-hour Holter monitoring were the most eligible for mapping and ablation, with a final success rate of 66%, versus the global success rate of 44%. Patients with persistent atrial fibrillation were not good candidates for focal ablation.

  8. Investigation into the optimum beam shape and fluence for selective ablation of dental calculus at lambda = 400 nm.

    Science.gov (United States)

    Schoenly, Joshua E; Seka, Wolf; Rechmann, Peter

    2010-01-01

    A frequency-doubled Ti:sapphire laser is shown to selectively ablate dental calculus. The optimal transverse shape of the laser beam, including its variability under water-cooling, is determined for selective ablation of dental calculus. Intensity profiles under various water-cooling conditions were optically observed. The 400-nm laser was coupled into a multimode optical fiber using an f = 2.5-cm lens and light-shaping diffuser. Water-cooling was supplied coaxially around the fiber. Five human tooth samples (four with calculus and one pristine) were irradiated perpendicular to the tooth surface while the tooth was moved back and forth at 0.3 mm/second, varying between 20 and 180 iterations. The teeth were imaged before and after irradiation using light microscopy with a flashing blue light-emitting diode (LED). An environmental scanning electron microscope imaged each tooth after irradiation. High-order super-Gaussian intensity profiles are observed at the output of a fiber coiled around a 4-in. diameter drum. Super-Gaussian beams have a more-homogenous fluence distribution than Gaussian beams and have a higher energy efficiency for selective ablation. Coaxial water-cooling does not noticeably distort the intensity distribution within 1 mm from the optical fiber. In contrast, lasers focused to a Gaussian cross section (Calculus is preferentially ablated at high fluences (> or =2 J/cm(2)); below this fluence, stalling occurs because of photo-bleaching of the calculus. Healthy dental hard tissue is not removed at fluences calculus with a frequency-doubled Ti:sapphire laser. Fluences over 2 J/cm(2) are required to remove calculus efficiently since photo-bleaching stalls calculus removal below that value.

  9. Blockade of CD7 expression in T cells for effective chimeric antigen receptor targeting of T-cell malignancies.

    Science.gov (United States)

    Png, Yi Tian; Vinanica, Natasha; Kamiya, Takahiro; Shimasaki, Noriko; Coustan-Smith, Elaine; Campana, Dario

    2017-11-28

    Effective immunotherapies for T-cell malignancies are lacking. We devised a novel approach based on chimeric antigen receptor (CAR)-redirected T lymphocytes. We selected CD7 as a target because of its consistent expression in T-cell acute lymphoblastic leukemia (T-ALL), including the most aggressive subtype, early T-cell precursor (ETP)-ALL. In 49 diagnostic T-ALL samples (including 14 ETP-ALL samples), median CD7 expression was >99%; CD7 expression remained high at relapse (n = 14), and during chemotherapy (n = 54). We targeted CD7 with a second-generation CAR (anti-CD7-41BB-CD3ζ), but CAR expression in T lymphocytes caused fratricide due to the presence of CD7 in the T cells themselves. To downregulate CD7 and control fratricide, we applied a new method (protein expression blocker [PEBL]), based on an anti-CD7 single-chain variable fragment coupled with an intracellular retention domain. Transduction of anti-CD7 PEBL resulted in virtually instantaneous abrogation of surface CD7 expression in all transduced T cells; 2.0% ± 1.7% were CD7 + vs 98.1% ± 1.5% of mock-transduced T cells (n = 5; P < .0001). PEBL expression did not impair T-cell proliferation, interferon-γ and tumor necrosis factor-α secretion, or cytotoxicity, and eliminated CAR-mediated fratricide. PEBL-CAR T cells were highly cytotoxic against CD7 + leukemic cells in vitro and were consistently more potent than CD7 + T cells spared by fratricide. They also showed strong anti-leukemic activity in cell line- and patient-derived T-ALL xenografts. The strategy described in this study fits well with existing clinical-grade cell manufacturing processes and can be rapidly implemented for the treatment of patients with high-risk T-cell malignancies.

  10. Primary intestinal T cell lymphomas in Indian patients - In search of enteropathic T cell lymphoma

    Directory of Open Access Journals (Sweden)

    Shet Tanuja

    2010-07-01

    Full Text Available Objective: This series of six intestinal T cell lymphomas (ITCL attempts to document enteropathy-associated T cell lymphoma (EATCL in India. Materials and Methods: A total of six ITCL were selected from 170 gastrointestinal lymphomas in last 10 years. Results: The cases studied included EATCL (4, ITCL with a CD4 positive phenotype (1 and ITCL NK/T cell type (1. Of the four EATCL, two occurred in the ileum, one in right colon and one in duodenum. In three EATCL cases, there was history of celiac disease or lactose intolerance and enteropathic changes were noted in the adjacent mucosa. These tumors had CD3+/CD8+/CD56 (+/-/CD4-/ Granzyme B+ immunophenotype. One EATCL was monomorphic small cell type (type II EATCL with a CD3+/CD8-CD56+/CD4-/ Granzyme B+ phenotype. EBER- ISH (Epstein Barr virus coded RNA′s- in situ hybridization revealed positive tumor cells in ITCL NK/T cell type and in bystander cells in three EATCL. Conclusion: ITCL are rare in Indian patients but do occur and comprise a mixture of the enteropathic and non-enteropathic subtypes.

  11. Role of T cell receptor affinity in the efficacy and specificity of adoptive T cell therapies

    Directory of Open Access Journals (Sweden)

    Jennifer D. Stone

    2013-08-01

    Full Text Available Over the last several years, there has been considerable progress in the treatment of cancer using gene modified adoptive T cell therapies. Two approaches have been used, one involving the introduction of a conventional alpha-beta T cell receptor (TCR against a pepMHC cancer antigen, and the second involving introduction of a chimeric antigen receptor (CAR consisting of a single-chain antibody as an Fv fragment (scFv linked to transmembrane and signaling domains. In this review, we focus on one aspect of TCR-mediated adoptive T cell therapies, the impact of the affinity of the alpha-beta TCR for the pepMHC cancer antigen on both efficacy and specificity. We discuss the advantages of higher affinity TCRs in mediating potent activity of CD4 T cells. This is balanced with the potential disadvantage of higher affinity TCRs in mediating greater self-reactivity against a wider range of structurally similar antigenic peptides, especially in synergy with the CD8 co-receptor. Both TCR affinity and target selection will influence potential safety issues. We suggest pre-clinical strategies that might be used to examine each TCR for possible on-target and off-target side effects due to self-reactivities, and to adjust TCR affinities accordingly.

  12. T-cell prolymphocytic leukemia

    OpenAIRE

    Graham, Robbie L.; Cooper, Barry; Krause, John R.

    2013-01-01

    T-cell prolymphocytic leukemia is a rare and unusual malignancy characterized by the proliferation of small- to medium-sized prolymphocytes of postthymic origin with distinctive clinical, morphologic, immunophenotypic, and cytogenetic features. Involvement of the peripheral blood, bone marrow, lymph nodes, liver, spleen, and skin can occur. The clinical course is typically very aggressive with poor response to conventional chemotherapy and short survival rates, and the only potential long-ter...

  13. Potentiating the antitumour response of CD8+ T cells by modulating cholesterol metabolism

    Science.gov (United States)

    Yang, Wei; Bai, Yibing; Xiong, Ying; Zhang, Jin; Chen, Shuokai; Zheng, Xiaojun; Meng, Xiangbo; Li, Lunyi; Wang, Jing; Xu, Chenguang; Yan, Chengsong; Wang, Lijuan; Chang, Catharine C. Y.; Chang, Ta-Yuan; Zhang, Ti; Zhou, Penghui; Song, Bao-Liang; Liu, Wanli; Sun, Shao-cong; Liu, Xiaolong; Li, Bo-liang; Xu, Chenqi

    2016-01-01

    CD8+ T cells have a central role in antitumour immunity, but their activity is suppressed in the tumour microenvironment1–4. Reactivating the cytotoxicity of CD8+ T cells is of great clinical interest in cancer immunotherapy. Here we report a new mechanism by which the antitumour response of mouse CD8+ T cells can be potentiated by modulating cholesterol metabolism. Inhibiting cholesterol esterification in T cells by genetic ablation or pharmacological inhibition of ACAT1, a key cholesterol esterification enzyme5, led to potentiated effector function and enhanced proliferation of CD8+ but not CD4+ T cells. This is due to the increase in the plasma membrane cholesterol level of CD8+ T cells, which causes enhanced T-cell receptor clustering and signalling as well as more efficient formation of the immunological synapse. ACAT1-deficient CD8+ T cells were better than wild-type CD8+ T cells at controlling melanoma growth and metastasis in mice. We used the ACAT inhibitor avasimibe, which was previously tested in clinical trials for treating atherosclerosis and showed a good human safety profile6,7, to treat melanoma in mice and observed a good antitumour effect. A combined therapy of avasimibe plus an anti-PD-1 antibody showed better efficacy than monotherapies in controlling tumour progression. ACAT1, an established target for atherosclerosis, is therefore also a potential target for cancer immunotherapy. PMID:26982734

  14. The timing of T cell priming and cycling

    Directory of Open Access Journals (Sweden)

    Reinhard eObst

    2015-11-01

    Full Text Available The proliferation of specific lymphocytes is the central tenet of the clonal selection paradigm. Antigen recognition by T cells triggers a series of events that produces expanded clones of differentiated effector cells. TCR signaling events are detectable within seconds and minutes and are likely to continue for hours and days in vivo. Here, I review the work done on the importance of TCR signals in the later part of the expansion phase of the primary T cell response, primarily regarding the regulation of the cell cycle in CD4+ and CD8+ cells. The results suggest a degree of programming by early signals for effector differentiation, particularly in the CD8+ T cell compartment, with optimal expansion supported by persistent antigen presentation later on. Differences to CD4+ T cell expansion and new avenues towards a molecular understanding of cell cycle regulation in lymphocytes are discussed.

  15. T cell depleted haploidentical transplantation: positive selection

    Directory of Open Access Journals (Sweden)

    Franco Aversa

    2011-06-01

    Full Text Available Interest in mismatched transplantation arises from the fact that a suitable one-haplotype mismatched donor is immediately available for virtually all patients, particularly for those who urgently need an allogenic transplant. Work on one haplotype-mismatched transplants has been proceeding for over 20 years all over the world and novel transplant techniques have been developed. Some centres have focused on the conditioning regimens and post transplant immune suppression; others have concentrated on manipulating the graft which may be a megadose of extensively T celldepleted or unmanipulated progenitor cells. Excellent engraftment rates are associated with a very low incidence of acute and chronic GVHD and regimen-related mortality even in patients who are over 50 years old. Overall, event-free survival and transplant-related mortality compare favourably with reports on transplants from sources of stem cells other than the matched sibling.

  16. Expansion of mycobacterium-reactive gamma delta T cells by a subset of memory helper T cells.

    Science.gov (United States)

    Vila, L M; Haftel, H M; Park, H S; Lin, M S; Romzek, N C; Hanash, S M; Holoshitz, J

    1995-04-01

    Human gamma delta T cells expressing the V gamma 9/V delta 2 T-cell receptor have been previously found to proliferate in response to certain microorganisms and to expand throughout life, presumably because of extrathymic activation by foreign antigens. In vitro expansion of V gamma 9/V delta 2 cells by mycobacteria has been previously shown to be dependent on accessory cells. In order to gain an insight into the mechanisms involved in the expansion of these cells, we have undertaken to identify the peripheral blood subset of cells on which proliferation of V gamma 9/V delta 2 cells in response to mycobacteria is dependent. Contrary to their role in antigen presentation to alpha beta T cells, professional antigen-presenting cells, such as monocytes, B cells, and dendritic cells, were unable to provide the cellular support for the expansion of V gamma 9/V delta 2 cells. Selective depletion of T-cell subsets, as well as the use of highly purified T-cell populations, indicated that the only subset of peripheral blood cells that could expand V gamma 9/V delta 2 cells were CD4+ CD45RO+ CD7- alpha beta T cells. These cells underwent distinct intracellular signaling events after stimulation with the mycobacterial antigen. Expansion of V gamma 9/V delta 2 cells by alpha beta T cells was dependent on cell-cell contact. This is the first evidence that a small subset of the memory helper T-cell population is exclusively responsible for the peripheral expansion of V gamma 9/V delta 2 cells. These data illustrate a unique aspect of antigen recognition by gamma delta T cells and provide new means to study their immune defense role.

  17. Adult T-Cell Leukemia/Lymphoma

    Science.gov (United States)

    ... Non-Hodgkin Lymphoma Peripheral T-Cell Lymphoma Primary Central Nervous System Lymphoma T-Cell Lymphoma Transformed Mycosis Fungoides Waldenstrom Macroglobulinemia Young Adult Lymphoma Overview Treatment Options Relapsed/Refractory Long-term ...

  18. Use of internal control T-cell populations in the flow cytometric evaluation for T-cell neoplasms.

    Science.gov (United States)

    Hunt, Alicia M; Shallenberger, Wendy; Ten Eyck, Stephen P; Craig, Fiona E

    2016-09-01

    Flow cytometry is an important tool for identification of neoplastic T-cells, but immunophenotypic abnormalities are often subtle and must be distinguished from nonneoplastic subsets. Use of internal control (IC) T-cells in the evaluation for T-cell neoplasms was explored, both as a quality measure and as a reference for evaluating abnormal antigen expression. All peripheral blood specimens (3-month period), or those containing abnormal T-cells (29-month period), stained with CD45 V500, CD2 V450, CD3 PE-Cy7, CD7 PE, CD4 Per-CP-Cy5.5, CD8 APC-H7, CD56 APC, CD16&57 FITC, were evaluated. IC T-cells were identified (DIVA, BD Biosciences) and median fluorescence intensity (MFI) recorded. Selected files were merged and reference templates generated (Infinicyt, Cytognos). IC T-cells were present in all specimens, including those with abnormal T-cells, but subsets were less well-represented. IC T-cell CD3 MFI differed between instruments (p = 0.0007) and subsets (p < 0.001), but not specimen categories, and served as a longitudinal process control. Merged files highlighted small unusual IC-T subsets: CD2+(dim) (0.25% total), CD2- (0.03% total). An IC reference template highlighted neoplastic T-cells, but was limited by staining variability (IC CD3 MFI reference samples different from test (p = 0.003)). IC T-cells present in the majority of specimens can serve as positive and longitudinal process controls. Use of IC T-cells as an internal reference is limited by variable representation of subsets. Analysis of merged IC T-cells from previously analyzed patient samples can alert the interpreter to less-well-recognized non-neoplastic subsets. However, application of a merged file IC reference template was limited by staining variability. © 2016 Clinical Cytometry Society. © 2016 International Clinical Cytometry Society.

  19. Regulatory T cells are strong promoters of acute ischemic stroke in mice by inducing dysfunction of the cerebral microvasculature.

    Science.gov (United States)

    Kleinschnitz, Christoph; Kraft, Peter; Dreykluft, Angela; Hagedorn, Ina; Göbel, Kerstin; Schuhmann, Michael K; Langhauser, Friederike; Helluy, Xavier; Schwarz, Tobias; Bittner, Stefan; Mayer, Christian T; Brede, Marc; Varallyay, Csanad; Pham, Mirko; Bendszus, Martin; Jakob, Peter; Magnus, Tim; Meuth, Sven G; Iwakura, Yoichiro; Zernecke, Alma; Sparwasser, Tim; Nieswandt, Bernhard; Stoll, Guido; Wiendl, Heinz

    2013-01-24

    We have recently identified T cells as important mediators of ischemic brain damage, but the contribution of the different T-cell subsets is unclear. Forkhead box P3 (FoxP3)-positive regulatory T cells (Tregs) are generally regarded as prototypic anti-inflammatory cells that maintain immune tolerance and counteract tissue damage in a variety of immune-mediated disorders. In the present study, we examined the role of Tregs after experimental brain ischemia/reperfusion injury. Selective depletion of Tregs in the DEREG mouse model dramatically reduced infarct size and improved neurologic function 24 hours after stroke and this protective effect was preserved at later stages of infarct development. The specificity of this detrimental Treg effect was confirmed by adoptive transfer experiments in wild-type mice and in Rag1(-/-) mice lacking lymphocytes. Mechanistically, Tregs induced microvascular dysfunction in vivo by increased interaction with the ischemic brain endothelium via the LFA-1/ICAM-1 pathway and platelets and these findings were confirmed in vitro. Ablation of Tregs reduced microvascular thrombus formation and improved cerebral reperfusion on stroke, as revealed by ultra-high-field magnetic resonance imaging at 17.6 Tesla. In contrast, established immunoregulatory characteristics of Tregs had no functional relevance. We define herein a novel and unexpected role of Tregs in a primary nonimmunologic disease state.

  20. The Ras GTPase-activating protein Rasal3 supports survival of naive T cells.

    Directory of Open Access Journals (Sweden)

    Ryunosuke Muro

    Full Text Available The Ras-mitogen-activated protein kinase (MAPK pathway is crucial for T cell receptor (TCR signaling in the development and function of T cells. The significance of various modulators of the Ras-MAPK pathway in T cells, however, remains to be fully understood. Ras-activating protein-like 3 (Rasal3 is an uncharacterized member of the SynGAP family that contains a conserved Ras GTPase-activating protein (GAP domain, and is predominantly expressed in the T cell lineage. In the current study, we investigated the function and physiological roles of Rasal3. Our results showed that Rasal3 possesses RasGAP activity, but not Rap1GAP activity, and represses TCR-stimulated ERK phosphorylation in a T cell line. In systemic Rasal3-deficient mice, T cell development in the thymus including positive selection, negative selection, and β-selection was unaffected. However, the number of naive, but not effector memory CD4 and CD8 T cell in the periphery was significantly reduced in Rasal3-deficient mice, and associated with a marked increase in apoptosis of these cells. Indeed, survival of Rasal3 deficient naive CD4 T cells in vivo by adoptive transfer was significantly impaired, whereas IL-7-dependent survival of naive CD4 T cells in vitro was unaltered. Collectively, Rasal3 is required for in vivo survival of peripheral naive T cells, contributing to the maintenance of optimal T cell numbers.

  1. Expression of inhibitory receptors on intratumoral T cells modulates the activity of a T cell-bispecific antibody targeting folate receptor

    Science.gov (United States)

    Schreiner, Jens; Thommen, Daniela S.; Herzig, Petra; Bacac, Marina; Klein, Christian; Roller, Andreas; Belousov, Anton; Levitsky, Victor; Savic, Spasenija; Moersig, Wolfgang; Uhlenbrock, Franziska; Heinzelmann-Schwarz, Viola A.; Umana, Pablo; Pisa, Pavel; von Bergwelt-Baildon, M.; Lardinois, Didier; Müller, Philipp; Karanikas, Vaios; Zippelius, Alfred

    2016-01-01

    ABSTRACT T-cell bispecific antibodies (TCBs) are a novel therapeutic tool designed to selectively recruit T-cells to tumor cells and simultaneously activate them. However, it is currently unknown whether the dysfunctional state of T-cells, embedded into the tumor microenvironment, imprints on the therapeutic activity of TCBs. We performed a comprehensive analysis of activation and effector functions of tumor-infiltrating T-cells (TILs) in different tumor types, upon stimulation by a TCB targeting folate receptor 1 and CD3 (FolR1-TCB). We observed a considerable heterogeneity in T-cell activation, cytokine production and tumor cell killing upon exposure to FolR1-TCB among different FolR1-expressing tumors. Of note, tumors presenting with a high frequency of PD-1hi TILs displayed significantly impaired tumor cell killing and T-cell function. Further characterization of additional T-cell inhibitory receptors revealed that PD-1hi TILs defined a T-cell subset with particularly high levels of multiple inhibitory receptors compared with PD-1int and PD-1neg T-cells. PD-1 blockade could restore cytokine secretion but not cytotoxicity of TILs in a subset of patients with scarce PD-1hi expressing cells; in contrast, patients with abundance of PD-1hi expressing T-cells did not benefit from PD-1 blockade. Our data highlight that FolR1-TCB is a promising novel immunotherapeutic treatment option which is capable of activating intratumoral T-cells in different carcinomas. However, its therapeutic efficacy may be substantially hampered by a pre-existing dysfunctional state of T-cells, reflected by abundance of intratumoral PD-1hi T-cells. These findings present a rationale for combinatorial approaches of TCBs with other therapeutic strategies targeting T-cell dysfunction. PMID:27057429

  2. Robust and Accurate Discrimination of Self/Non-Self Antigen Presentations by Regulatory T Cell Suppression

    OpenAIRE

    Furusawa, Chikara; Yamaguchi, Tomoyuki

    2016-01-01

    The immune response by T cells usually discriminates self and non-self antigens, even though the negative selection of self-reactive T cells is imperfect and a certain fraction of T cells can respond to self-antigens. In this study, we construct a simple mathematical model of T cell populations to analyze how such self/non-self discrimination is possible. The results demonstrate that the control of the immune response by regulatory T cells enables a robust and accurate discrimination of self ...

  3. PD-L1-specific T cells

    DEFF Research Database (Denmark)

    Ahmad, Shamaila Munir; Borch, Troels Holz; Hansen, Morten

    2016-01-01

    -specific T cells that recognize both PD-L1-expressing immune cells and malignant cells. Thus, PD-L1-specific T cells have the ability to modulate adaptive immune reactions by reacting to regulatory cells. Thus, utilization of PD-L1-derived T cell epitopes may represent an attractive vaccination strategy...... for targeting the tumor microenvironment and for boosting the clinical effects of additional anticancer immunotherapy. This review summarizes present information about PD-L1 as a T cell antigen, depicts the initial findings about the function of PD-L1-specific T cells in the adjustment of immune responses...

  4. T cell resistance to activation by dendritic cells requires long-term culture in simulated microgravity

    Science.gov (United States)

    Bradley, Jillian H.; Stein, Rachel; Randolph, Brad; Molina, Emily; Arnold, Jennifer P.; Gregg, Randal K.

    2017-11-01

    Immune impairment mediated by microgravity threatens the success of space exploration requiring long-duration spaceflight. The cells of most concern, T lymphocytes, coordinate the host response against microbial and cancerous challenges leading to elimination and long-term protection. T cells are activated upon recognition of specific microbial peptides bound on the surface of antigen presenting cells, such as dendritic cells (DC). Subsequently, this engagement results in T cell proliferation and differentiation into effector T cells driven by autocrine interleukin-2 (IL-2) and other cytokines. Finally, the effector T cells acquire the weaponry needed to destroy microbial invaders and tumors. Studies conducted on T cells during spaceflight, or using Earth-based culture systems, have shown reduced production of cytokines, proliferation and effector functions as compared to controls. This may account for the cases of viral reactivation events and opportunistic infections associated with astronauts of numerous missions. This work has largely been based upon the outcome of T cell activation by stimulatory factors that target select T cell signaling pathways rather than the complex, signaling events related to the natural process of antigen presentation by DC. This study tested the response of an ovalbumin peptide-specific T cell line, OT-II TCH, to activation by DC when the T cells were cultured 24-120 h in a simulated microgravity (SMG) environment generated by a rotary cell culture system. Following 72 h culture of T cells in SMG (SMG-T) or control static (Static-T) conditions, IL-2 production by the T cells was reduced in SMG-T cells compared to Static-T cells upon stimulation by phorbol 12-myristate 13-acetate (PMA) and ionomycin. However, when the SMG-T cells were stimulated with DC and peptide, IL-2 was significantly increased compared to Static-T cells. Such enhanced IL-2 production by SMG-T cells peaked at 72 h SMG culture time and decreased thereafter. When

  5. T cell resistance to activation by dendritic cells requires long-term culture in simulated microgravity.

    Science.gov (United States)

    Bradley, Jillian H; Stein, Rachel; Randolph, Brad; Molina, Emily; Arnold, Jennifer P; Gregg, Randal K

    2017-11-01

    Immune impairment mediated by microgravity threatens the success of space exploration requiring long-duration spaceflight. The cells of most concern, T lymphocytes, coordinate the host response against microbial and cancerous challenges leading to elimination and long-term protection. T cells are activated upon recognition of specific microbial peptides bound on the surface of antigen presenting cells, such as dendritic cells (DC). Subsequently, this engagement results in T cell proliferation and differentiation into effector T cells driven by autocrine interleukin-2 (IL-2) and other cytokines. Finally, the effector T cells acquire the weaponry needed to destroy microbial invaders and tumors. Studies conducted on T cells during spaceflight, or using Earth-based culture systems, have shown reduced production of cytokines, proliferation and effector functions as compared to controls. This may account for the cases of viral reactivation events and opportunistic infections associated with astronauts of numerous missions. This work has largely been based upon the outcome of T cell activation by stimulatory factors that target select T cell signaling pathways rather than the complex, signaling events related to the natural process of antigen presentation by DC. This study tested the response of an ovalbumin peptide-specific T cell line, OT-II TCH, to activation by DC when the T cells were cultured 24-120 h in a simulated microgravity (SMG) environment generated by a rotary cell culture system. Following 72 h culture of T cells in SMG (SMG-T) or control static (Static-T) conditions, IL-2 production by the T cells was reduced in SMG-T cells compared to Static-T cells upon stimulation by phorbol 12-myristate 13-acetate (PMA) and ionomycin. However, when the SMG-T cells were stimulated with DC and peptide, IL-2 was significantly increased compared to Static-T cells. Such enhanced IL-2 production by SMG-T cells peaked at 72 h SMG culture time and decreased thereafter

  6. Effect of selective T cell depletion of host and/or donor bone marrow on lymphopoietic repopulation, tolerance, and graft-vs-host disease in mixed allogeneic chimeras (B10 + B10.D2----B10)

    International Nuclear Information System (INIS)

    Ildstad, S.T.; Wren, S.M.; Bluestone, J.A.; Barbieri, S.A.; Stephany, D.; Sachs, D.H.

    1986-01-01

    Reconstitution of lethally irradiated mice with a mixture of T cell-depleted syngeneic plus T cell-depleted allogeneic bone marrow (B10 + B10.D2----B10) leads to the induction of mixed lymphopoietic chimerism, excellent survivals, specific in vivo transplantation tolerance to subsequent donor strain skin grafts, and specific in vitro unresponsiveness to allogeneic donor lymphoid elements as assessed by mixed lymphocyte reaction (MLR) proliferative and cell-mediated lympholysis (CML) cytotoxicity assays. When B10 recipient mice received mixed marrow inocula in which the syngeneic component had not been T cell depleted, whether or not the allogeneic donor marrow was treated, they repopulated exclusively with host-type cells, promptly rejected donor-type skin allografts, and were reactive in vitro to the allogeneic donor by CML and MLR assays. In contrast, T cell depletion of the syngeneic component of the mixed marrow inocula resulted in specific acceptance of allogeneic donor strain skin grafts. Such animals were specifically unreactive to allogeneic donor lymphoid elements in vitro by CML and MLR, but were reactive to third party. When both the syngeneic and allogeneic marrow were T cell depleted, variable percentages of host- and donor-type lymphoid elements were detected in the mixed reconstituted host. When only the syngeneic bone marrow was T cell depleted, animals repopulated exclusively with donor-type cells. Although these animals had detectable in vitro anti-host (B10) reactivity by CML and MLR and reconstituted as fully allogeneic chimeras, they exhibited excellent survival and had no in vivo evidence for graft-vs-host disease. Experiments in which untreated donor spleen cells were added to the inocula in this last group suggest that the presence of T cell-depleted syngeneic bone marrow cells diminishes graft-vs-host disease and the mortality from it

  7. Direct chemical-analysis of uv laser-ablation products of organic polymers by using selective ion monitoring mode in gas-chromatography mass-spectrometry

    Science.gov (United States)

    Cho, Yirang; Lee, H.W.; Fountain, S.T.; Lubman, D.M.

    1994-01-01

    Trace quantities of laser ablated organic polymers were analyzed by using commercial capillary column gas chromatography/mass spectrometry; the instrument was modified so that the laser ablation products could be introduced into the capillary column directly and the constituents of each peak in the chromatogram were identified by using a mass spectrometer. The present study takes advantage of the selective ion monitoring mode for significantly improving the sensitivity of the mass spectrometer as a detector, which is critical in analyzing the trace quantities and confirming the presence or absence of the species of interest in laser ablated polymers. The initial composition of the laser ablated polymers was obtained by using an electron impact reflectron time-of-flight mass spectrometer and the possible structure of the fragments observed in the spectra was proposed based on the structure of the polymers.

  8. Cell-intrinsic role for NF-kappa B-inducing kinase in peripheral maintenance but not thymic development of Foxp3+ regulatory T cells in mice.

    Directory of Open Access Journals (Sweden)

    Susan E Murray

    Full Text Available NF-κB inducing kinase (NIK, MAP3K14 is a key signaling molecule in non-canonical NF-κB activation, and NIK deficient mice have been instrumental in deciphering the immunologic role of this pathway. Global ablation of NIK prevents lymph node development, impairs thymic stromal development, and drastically reduces B cells. Despite altered thymic selection, T cell numbers are near normal in NIK deficient mice. The exception is CD4(+ regulatory T cells (Tregs, which are reduced in the thymus and periphery. Defects in thymic stroma are known to contribute to impaired Treg generation, but whether NIK also plays a cell intrinsic role in Tregs is unknown. Here, we compared intact mice with single and mixed BM chimeric mice to assess the intrinsic role of NIK in Treg generation and maintenance. We found that while NIK expression in stromal cells suffices for normal thymic Treg development, NIK is required cell-intrinsically to maintain peripheral Tregs. In addition, we unexpectedly discovered a cell-intrinsic role for NIK in memory phenotype conventional T cells that is masked in intact mice, but revealed in BM chimeras. These results demonstrate a novel role for NIK in peripheral regulatory and memory phenotype T cell homeostasis.

  9. T-cell help permits memory CD8(+) T-cell inflation during cytomegalovirus latency.

    Science.gov (United States)

    Walton, Senta M; Torti, Nicole; Mandaric, Sanja; Oxenius, Annette

    2011-08-01

    CD4(+) T cells are implied to sustain CD8(+) T-cell responses during persistent infections. As CD4(+) T cells are often themselves antiviral effectors, they might shape CD8(+) T-cell responses via help or via controlling antigen load. We used persistent murine CMV (MCMV) infection to dissect the impact of CD4(+) T cells on virus-specific CD8(+) T cells, distinguishing between increased viral load in the absence of CD4(+) T cells and CD4(+) T-cell-mediated helper mechanisms. Absence of T-helper cells was associated with sustained lytic MCMV replication and led to a slow and gradual reduction of the size and function of the MCMV-specific CD8(+) T-cell pool. However, when virus replication was controlled in the absence of CD4(+) T cells, CD8(+) T-cell function was comparably impaired, but in addition CD8(+) T-cell inflation, a hallmark of CMV infection, was completely abolished. Thus, CD8(+) T-cell inflation during latent CMV infection is strongly dependent on CD4(+) T-cell helper functions, which can partially be compensated by ongoing lytic viral replication in the absence of CD4(+) T cells. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. PET imaging of T cells: Target identification and feasibility assessment.

    Science.gov (United States)

    Auberson, Yves P; Briard, Emmanuelle; Rudolph, Bettina; Kaupmann, Klemen; Smith, Paul; Oberhauser, Berndt

    2018-06-01

    Imaging T cells using positron emission tomography (PET) would be highly useful for diagnosis and monitoring in immunology and oncology patients. There are however no obvious targets that can be used to develop imaging agents for this purpose. We evaluated several potential target proteins with selective expression in T cells, and for which lead molecules were available: PKC , Lck, ZAP70 and Itk. Ultimately, we focused on Itk (interleukin-2-inducible T cell kinase) and identified a tool molecule with properties suitable for in vivo imaging of T cells, (5aR)-5,5-difluoro-5a-methyl-N-(1-((S)-3-(methylsulfonyl)-phenyl)(tetrahydro-2H-pyran-4-yl)methyl)-1H-pyrazol-4-yl)-1,4,4a,5,5a,6-hexahydro-cyclopropa[f]-indazole-3-carboxamide (23). While not having the optimal profile for clinical use, this molecule indicates that it might be possible to develop Itk-selective PET ligands for imaging the distribution of T cells in patients. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Trace isotope analysis using resonance ionization mass spectrometry based on isotope selection with doppler shift of laser ablated atoms

    International Nuclear Information System (INIS)

    Higuchi, Yuki; Watanabe, Kenichi; Kawarabayashi, Jun; Iguchi, Tetsuo

    2005-01-01

    We have proposed a novel isotope selective Resonance Ionization Mass Spectroscopy (RIMS) concept, which can avoid the Doppler broadening on solid sample direct measurement based on laser ablation technique. We have succeeded in experimentally demonstrating the principle of our RIMS concept. Through comparison between the simulated and experimental results, we have validated the simulation model. It would be concluded from these results that we could achieve the isotope selectivity defined as the ratio of 41 Ca to 40 Ca sensitivity to be 4.5x10 10 by adopting the multi-step excitation scheme in the present method. As future works, we will try to experimentally perform the multi-step excitation scheme and improve the detection efficiency by modifying the ion extraction configuration. (author)

  12. Selective silencing of full-length CD80 but not IgV-CD80 leads to impaired clonal deletion of self-reactive T cells and altered regulation of immune responses.

    Science.gov (United States)

    Bugeon, L; Hargreaves, R E; Crompton, T; Outram, S; Rahemtulla, A; Porter, A C; Dallman, M J

    2001-01-01

    Co-stimulation provided by the B7 family of proteins underpins the development of protective immunity. There are three identified members of this family: CD80, its splice variant IgV-CD80 and CD86. It has hitherto been difficult to analyze the expression and function of IgV-CD80 since there are no appropriate reagents capable of distinguishing it from CD80. We have generated mice, by gene targeting, the lack CD80 whilst maintaining expression of IgV-CD80. Mutant animals did not delete T cells bearing mammary tumor virus-reactive TCR as efficiently as wild-type animals. We also demonstrate the importance of IgV-CD80 in the responses of recently activated cells and reveal a role for CD80 in sustaining T cell responses. CD86, whilst critical to primary T cell activation, made only a minor contribution to re-activation of normal cells.

  13. Selective ablation of dental enamel and dentin using femtosecond laser pulses

    International Nuclear Information System (INIS)

    Lizarelli, R F Z; Costa, M M; Carvalho-Filho, E; Bagnato, V S; Nunes, F D

    2008-01-01

    The study of the interaction of intense laser light with matter, as well as transient response of atoms and molecules is very appropriated because of the laser energy concentration in a femtosecond optical pulses. The fundamental problem to be solved is to find tools and techniques which allow us to observe and manipulate on a femtosecond time scale the photonics events on and into the matter. Six third human extracted molars were exposed to a femtosecond Ti:Sapphire Q-switched and mode locked laser (Libra-S, Coherent, Palo Alto, CA, USA), emitting pulses with 70 fs width, radiation wavelength of 801 nm, at a constant pulse repetition rate of 1 KHz. The laser was operated at different power levels (70 to 400 mW) with constant exposition time of 10 seconds, at focused and defocused mode. Enamel and dentin surfaces were evaluated concerned ablation rate and morphological aspects under scanning electron microscopic. The results in this present experiment suggest that at the focused mode and under higher average power, enamel tissues present microcavities with higher depth and very precise edges, but, while dentin shows a larger melt-flushing, lower depth and melting and solidification aspect. In conclusion, it is possible to choose hard or soft ablation, under lower and higher average power, respectively, revealing different aspects of dental enamel and dentin, depending on the average power, fluence and distance from the focal point of the ultra-short pulse laser on the tooth surface

  14. ONC201 selectively induces apoptosis in cutaneous T-cell lymphoma cells via activating pro-apoptotic integrated stress response and inactivating JAK/STAT and NF-κB pathways

    OpenAIRE

    Ni, Xiao; Zhang, Xiang; Hu, Cheng-Hui; Langridge, Timothy; Tarapore, Rohinton S.; Allen, Joshua E.; Oster, Wolfgang; Duvic, Madeleine

    2017-01-01

    Cutaneous T-cell lymphomas (CTCLs) are extremely symptomatic and still incurable, and more effective and less toxic therapies are urgently needed. ONC201, an imipridone compound, has shown efficacy in pre-clinical studies in multiple advanced cancers. This study was to evaluate the anti-tumor activity of ONC201 on CTCL cells. The effect of ONC201 on the cell growth and apoptosis were evaluated in CTCL cell lines (n=8) and primary CD4+ malignant T cells isolated from CTCL patients (n=5). ONC20...

  15. Driving CAR T-cells forward

    Science.gov (United States)

    Jackson, Hollie J.; Rafiq, Sarwish; Brentjens, Renier J.

    2017-01-01

    The engineered expression of chimeric antigen receptors (CARs) on the surface of T cells enables the redirection of T-cell specificity. Early clinical trials using CAR T cells for the treatment of patients with cancer showed modest results, but the impressive outcomes of several trials of CD19-targeted CAR T cells in the treatment of patients with B-cell malignancies have generated an increased enthusiasm for this approach. Important lessons have been derived from clinical trials of CD19-specific CAR T cells, and ongoing clinical trials are testing CAR designs directed at novel targets involved in haematological and solid malignancies. In this Review, we discuss these trials and present strategies that can increase the antitumour efficacy and safety of CAR T-cell therapy. Given the fast-moving nature of this field, we only discuss studies with direct translational application currently or soon-to-be tested in the clinical setting. PMID:27000958

  16. Asymptomatic memory CD8+ T cells

    Science.gov (United States)

    Khan, Arif Azam; Srivastava, Ruchi; Lopes, Patricia Prado; Wang, Christine; Pham, Thanh T; Cochrane, Justin; Thai, Nhi Thi Uyen; Gutierrez, Lucas; BenMohamed, Lbachir

    2014-01-01

    Generation and maintenance of high quantity and quality memory CD8+ T cells determine the level of protection from viral, bacterial, and parasitic re-infections, and hence constitutes a primary goal for T cell epitope-based human vaccines and immunotherapeutics. Phenotypically and functionally characterizing memory CD8+ T cells that provide protection against herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) infections, which cause blinding ocular herpes, genital herpes, and oro-facial herpes, is critical for better vaccine design. We have recently categorized 2 new major sub-populations of memory symptomatic and asymptomatic CD8+ T cells based on their phenotype, protective vs. pathogenic function, and anatomical locations. In this report we are discussing a new direction in developing T cell-based human herpes vaccines and immunotherapeutics based on the emerging new concept of “symptomatic and asymptomatic memory CD8+ T cells.” PMID:24499824

  17. T Cell Genesis: In Vitro Veritas Est?

    OpenAIRE

    Brauer, Patrick M.; Singh, Jastaranpreet; Xhiku, Sintia; Zúñiga-Pflücker, Juan Carlos

    2016-01-01

    T cells, as orchestrators of the adaptive immune response, serve important physiological and potentially therapeutic roles, for example in cancer immunotherapy. T cells are readily isolated from patients; however, the yield of antigen-specific T cells is limited, thus making their clinical use challenging. Therefore, the generation of T lymphocytes from hematopoietic stem/progenitor cells (HSPCs) and human pluripotent stem cells (PSCs) in vitro provides an attractive method for large-scale pr...

  18. Palindromic nucleotide analysis in human T cell receptor rearrangements.

    Directory of Open Access Journals (Sweden)

    Santosh K Srivastava

    Full Text Available Diversity of T cell receptor (TCR genes is primarily generated by nucleotide insertions upon rearrangement from their germ line-encoded V, D and J segments. Nucleotide insertions at V-D and D-J junctions are random, but some small subsets of these insertions are exceptional, in that one to three base pairs inversely repeat the sequence of the germline DNA. These short complementary palindromic sequences are called P nucleotides. We apply the ImmunoSeq deep-sequencing assay to the third complementarity determining region (CDR3 of the β chain of T cell receptors, and use the resulting data to study P nucleotides in the repertoire of naïve and memory CD8(+ and CD4(+ T cells. We estimate P nucleotide distributions in a cross section of healthy adults and different T cell subtypes. We show that P nucleotide frequency in all T cell subtypes ranges from 1% to 2%, and that the distribution is highly biased with respect to the coding end of the gene segment. Classification of observed palindromic sequences into P nucleotides using a maximum conditional probability model shows that single base P nucleotides are very rare in VDJ recombination; P nucleotides are primarily two bases long. To explore the role of P nucleotides in thymic selection, we compare P nucleotides in productive and non-productive sequences of CD8(+ naïve T cells. The naïve CD8(+ T cell clones with P nucleotides are more highly expanded.

  19. CAR-T cells are serial killers.

    Science.gov (United States)

    Davenport, Alexander J; Jenkins, Misty R; Ritchie, David S; Prince, H Miles; Trapani, Joseph A; Kershaw, Michael H; Darcy, Phillip K; Neeson, Paul J

    2015-12-01

    Chimeric antigen receptor (CAR) T cells have enjoyed unprecedented clinical success against haematological malignancies in recent years. However, several aspects of CAR T cell biology remain unknown. We recently compared CAR and T cell receptor (TCR)-based killing in the same effector cell and showed that CAR T cells can not only efficiently kill single tumor targets, they can also kill multiple tumor targets in a sequential manner. Single and serial killing events were not sustained long term due to CAR down-regulation after 20 hours.

  20. Mechanisms behind functional avidity maturation in T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak, Martin; Geisler, Carsten

    2012-01-01

    During an immune response antigen-primed B-cells increase their antigen responsiveness by affinity maturation mediated by somatic hypermutation of the genes encoding the antigen-specific B-cell receptor (BCR) and by selection of higher-affinity B cell clones. Unlike the BCR, the T-cell receptor...

  1. Genetically modified T cells in cancer therapy: opportunities and challenges

    Directory of Open Access Journals (Sweden)

    Michaela Sharpe

    2015-04-01

    Full Text Available Tumours use many strategies to evade the host immune response, including downregulation or weak immunogenicity of target antigens and creation of an immune-suppressive tumour environment. T cells play a key role in cell-mediated immunity and, recently, strategies to genetically modify T cells either through altering the specificity of the T cell receptor (TCR or through introducing antibody-like recognition in chimeric antigen receptors (CARs have made substantial advances. The potential of these approaches has been demonstrated in particular by the successful use of genetically modified T cells to treat B cell haematological malignancies in clinical trials. This clinical success is reflected in the growing number of strategic partnerships in this area that have attracted a high level of investment and involve large pharmaceutical organisations. Although our understanding of the factors that influence the safety and efficacy of these therapies has increased, challenges for bringing genetically modified T-cell immunotherapy to many patients with different tumour types remain. These challenges range from the selection of antigen targets and dealing with regulatory and safety issues to successfully navigating the routes to commercial development. However, the encouraging clinical data, the progress in the scientific understanding of tumour immunology and the improvements in the manufacture of cell products are all advancing the clinical translation of these important cellular immunotherapies.

  2. Regulatory Eosinophils Suppress T Cells Partly through Galectin-10.

    Science.gov (United States)

    Lingblom, Christine; Andersson, Jennie; Andersson, Kerstin; Wennerås, Christine

    2017-06-15

    Eosinophils have the capacity to regulate the function of T cell subsets. Our aim was to test the hypothesis of the existence of a regulatory subset of eosinophils. Human eosinophils were incubated with T cells that were stimulated with allogeneic leukocytes or CD3/CD28 cross-linking. After 2 d of coculture, 11% of the eosinophils gained CD16 expression. A CD16 hi subset of eosinophils, encompassing 1-5% of all eosinophils, was also identified in the blood of healthy subjects. FACS sorting showed that these CD16 hi eosinophils were significantly stronger suppressors of T cell proliferation than were conventional CD16 neg eosinophils. Human eosinophils contain stores of the immunoregulatory protein galectin-10. We found that Ab-mediated neutralization of galectin-10 partially abrogated the suppressive function of the eosinophils. Moreover, recombinant galectin-10 by itself was able to suppress T cell proliferation. Finally, we detected galectin-10-containing immune synapses between eosinophils and lymphocytes. To conclude, we describe a subset of suppressive eosinophils expressing CD16 that may escape detection because CD16-based negative selection is the standard procedure for the isolation of human eosinophils. Moreover, we show that galectin-10 functions as a T cell-suppressive molecule in eosinophils. Copyright © 2017 by The American Association of Immunologists, Inc.

  3. Regulatory T Cells in Radiotherapeutic Responses

    International Nuclear Information System (INIS)

    Schaue, Dörthe; Xie, Michael W.; Ratikan, Josephine A.; McBride, William H.

    2012-01-01

    Radiation therapy (RT) can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling “danger.” The multiple mechanisms that can be evoked include a shift toward a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs), suppressor macrophages, and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the “brakes” on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer.

  4. Regulatory T cells in radiotherapeutic responses

    Directory of Open Access Journals (Sweden)

    Dörthe eSchaue

    2012-08-01

    Full Text Available Radiation therapy (RT can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling danger. The multiple mechanisms that can be evoked include a shift towards a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs, suppressor macrophages and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the brakes on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer.

  5. REGULATORY T CELLS AND VASECTOMY

    Science.gov (United States)

    Rival, Claudia; Wheeler, Karen; Jeffrey, Sarah; Qiao, Hui; Luu, Brian; Tewalt, Eric F; Engelhard, Victor H; Tardif, Stephen; Hardy, Daniel; del Rio, Roxana; Teuscher, Cory; Tung, Kenneth

    2013-01-01

    CD4+CD25+ regulatory T cells (Tregs) strongly influence the early and late autoimmune responses to meiotic germ cell antigens (MGCA) and the gonadal immunopathology in vasectomized mice. This is supported by the published and recently acquired information presented here. Within 24 hours of unilateral vasectomy (uni-vx) the ipsilateral epididymis undergoes epithelial cell apoptosis followed by necrosis, severe inflammation, and granuloma formation. Unexpectedly, vasectomy alone induced MGCA-specific tolerance. In contrast, uni-vx plus simultaneous Treg depletion resulted in MGCA-specific autoimmune response and bilateral autoimmune orchitis. Both tolerance and autoimmunity were strictly linked to the early epididymal injury. We now discovered that testicular autoimmunity in uni-vx mice did not occur when Treg depletion was delayed by one week. Remarkably, this delayed Treg depletion also prevented tolerance induction. Therefore, tolerance depends on a rapid de novo Treg response to MGCA exposed after vasectomy. Moreover, tolerance was blunted in mice genetically deficient in PD-1 ligand, suggesting the involvement of induced Treg. We conclude that pre-existing natural Treg prevents post-vasectomy autoimmunity, whereas vasectomy-induced Treg maintains post-vasectomy tolerance. We further discovered that vasectomized mice were still resistant to autoimmune orchitis induction for at least 12–16 months; thus, tolerance is long-lasting. Although significant sperm autoantibodies of low titers became detectable in uni-vx mice at seven months, the antibody titers fluctuated over time, suggesting a dynamic “balance” between the autoimmune and tolerance states. Finally, we observed severe epididymal fibrosis and hypo-spermatogenesis at 12 months after uni-vx: findings of highly critical clinical significance. PMID:24080233

  6. PSAPP mice exhibit regionally selective reductions in gliosis and plaque deposition in response to S100B ablation

    Directory of Open Access Journals (Sweden)

    Young Keith A

    2010-11-01

    Full Text Available Abstract Background Numerous studies have reported that increased expression of S100B, an intracellular Ca2+ receptor protein and secreted neuropeptide, exacerbates Alzheimer's disease (AD pathology. However, the ability of S100B inhibitors to prevent/reverse AD histopathology remains controversial. This study examines the effect of S100B ablation on in vivo plaque load, gliosis and dystrophic neurons. Methods Because S100B-specific inhibitors are not available, genetic ablation was used to inhibit S100B function in the PSAPP AD mouse model. The PSAPP/S100B-/- line was generated by crossing PSAPP double transgenic males with S100B-/- females and maintained as PSAPP/S100B+/- crosses. Congo red staining was used to quantify plaque load, plaque number and plaque size in 6 month old PSAPP and PSAPP/S100B-/- littermates. The microglial marker Iba1 and astrocytic marker glial fibrillary acidic protein (GFAP were used to quantify gliosis. Dystrophic neurons were detected with the phospho-tau antibody AT8. S100B immunohistochemistry was used to assess the spatial distribution of S100B in the PSAPP line. Results PSAPP/S100B-/- mice exhibited a regionally selective decrease in cortical but not hippocampal plaque load when compared to PSAPP littermates. This regionally selective reduction in plaque load was accompanied by decreases in plaque number, GFAP-positive astrocytes, Iba1-positive microglia and phospho-tau positive dystrophic neurons. These effects were not attributable to regional variability in the distribution of S100B. Hippocampal and cortical S100B immunoreactivity in PSAPP mice was associated with plaques and co-localized with astrocytes and microglia. Conclusions Collectively, these data support S100B inhibition as a novel strategy for reducing cortical plaque load, gliosis and neuronal dysfunction in AD and suggest that both extracellular as well as intracellular S100B contribute to AD histopathology.

  7. The role of Protein Kinase Cη in T cell biology

    Directory of Open Access Journals (Sweden)

    Nicholas R.J. Gascoigne

    2012-06-01

    Full Text Available Protein kinase Cη (PKCη is a member of the novel PKC subfamily, which also includes δ, ε, and θ isoforms. Compared to the other novel PKCs, the function of PKCη in the immune system is largely unknown. Several studies have started to reveal the role of PKCη, particularly in T cells. PKCη is highly expressed in T cells, and is upregulated during thymocyte positive selection. Interestingly, like the θ isoform, PKCη is also recruited to the immunological synapse that is formed between a T cell and an antigen-presenting cell. However, unlike PKCθ, which becomes concentrated to the central region of the synapse, PKCη remains in a diffuse pattern over the whole area of the synapse, suggesting distinctive roles of these two isoforms in signal transduction. Although PKCη is dispensable for thymocyte development, further analysis of PKCη− or PKCθ−deficient and double knockout mice revealed the redundancy of these two isoforms in thymocyte development. In contrast, PKCη rather than PKCθ, plays an important role for T cell homeostatic proliferation, which requires recognition of self-antigen. Another piece of evidence demonstrating that PKCη and PKCθ have isoform specific as well as redundant roles come from the analysis of CD4 to CD8 T cell ratios in the periphery of these knockout mice. Deficiency in PKCη or PKCθ had opposing effects as PKCη knockout mice had a higher ratio of CD4 to CD8 T cells compared to that of wild-type mice, whereas PKCθ-deficient mice had a lower ratio. Biochemical studies showed that calcium flux and NFκB translocation is impaired in PKCη-deficient T cells upon TCR crosslinking stimulation, a character shared with PKCθ-deficient T cells. However, unlike the case with PKCθ, the mechanistic study of PKCη is at early stage and the signaling pathways involving PKCη, at least in T cells, are essentially unknown. In this review, we will cover the topics mentioned above as well as provide some

  8. Regulation of T cell responses in atherosclerosis

    NARCIS (Netherlands)

    Puijvelde, Gijsbrecht Henricus Maria van

    2007-01-01

    One of the most important characteristics of atherosclerosis is the chronic inflammatory response in which T cells and NKT cells are very important. In this thesis several methods to modulate the activity of these T and NKT cells in atherosclerosis are described. The induction of regulatory T cells

  9. Cytotoxic human CD4(+) T cells

    NARCIS (Netherlands)

    van de Berg, Pablo J.; van Leeuwen, Ester M.; ten Berge, Ineke J.; van Lier, Rene

    2008-01-01

    The induction of adaptive immune responses critically depends on helper signals provided by CD4(+) T cells. These signals not only license antigen presenting cells (APC) to activate naïve CD8(+) T cells leading to the formation of vast numbers of cytotoxic T lymphocytes but also support the

  10. The numerology of T cell functional diversity.

    Science.gov (United States)

    Haining, W Nicholas

    2012-01-27

    Memory T cells are heterogeneous in phenotype and function. In this issue of Immunity, Newell et al. (2012) use a new flow cytometry platform to show that the functional heterogeneity of the human T cell compartment is even greater than previously thought. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. The Numerology of T Cell Functional Diversity

    OpenAIRE

    Haining, W. Nicholas

    2012-01-01

    Memory T cells are heterogeneous in phenotype and function. In this issue of Immunity Newell et al. (2012) use a new flow cytometry platform to show that the functional heterogeneity in the human T cell compartment is even greater than expected.

  12. Recurrence predictive models for patients with hepatocellular carcinoma after radiofrequency ablation using support vector machines with feature selection methods.

    Science.gov (United States)

    Liang, Ja-Der; Ping, Xiao-Ou; Tseng, Yi-Ju; Huang, Guan-Tarn; Lai, Feipei; Yang, Pei-Ming

    2014-12-01

    Recurrence of hepatocellular carcinoma (HCC) is an important issue despite effective treatments with tumor eradication. Identification of patients who are at high risk for recurrence may provide more efficacious screening and detection of tumor recurrence. The aim of this study was to develop recurrence predictive models for HCC patients who received radiofrequency ablation (RFA) treatment. From January 2007 to December 2009, 83 newly diagnosed HCC patients receiving RFA as their first treatment were enrolled. Five feature selection methods including genetic algorithm (GA), simulated annealing (SA) algorithm, random forests (RF) and hybrid methods (GA+RF and SA+RF) were utilized for selecting an important subset of features from a total of 16 clinical features. These feature selection methods were combined with support vector machine (SVM) for developing predictive models with better performance. Five-fold cross-validation was used to train and test SVM models. The developed SVM-based predictive models with hybrid feature selection methods and 5-fold cross-validation had averages of the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and area under the ROC curve as 67%, 86%, 82%, 69%, 90%, and 0.69, respectively. The SVM derived predictive model can provide suggestive high-risk recurrent patients, who should be closely followed up after complete RFA treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Selective Depletion of αβ T Cells and B Cells for Human Leukocyte Antigen-Haploidentical Hematopoietic Stem Cell Transplantation. A Three-Year Follow-Up of Procedure Efficiency.

    Science.gov (United States)

    Li Pira, Giuseppina; Malaspina, David; Girolami, Elia; Biagini, Simone; Cicchetti, Elisabetta; Conflitti, Gianpiero; Broglia, Manuel; Ceccarelli, Stefano; Lazzaro, Stefania; Pagliara, Daria; Meschini, Antonella; Bertaina, Alice; Montanari, Mauro; Locatelli, Franco

    2016-11-01

    HLA-haploidentical family donors represent a valuable option for children requiring allogeneic hematopoietic stem cell transplantation (HSCT). Because graft-versus-host diseases (GVHD) is a major complication of HLA-haploidentical HSCT because of alloreactive T cells in the graft, different methods have been used for ex vivo T cell depletion. Removal of donor αβ T cells, the subset responsible for GVHD, and of B cells, responsible for post-transplantation lymphoproliferative disorders, have been recently developed for HLA-haploidentical HSCT. This manipulation preserves, in addition to CD34 +  progenitors, natural killer, γδ T, and monocytes/dendritic cells, contributing to anti-leukemia activity and protection against infections. We analyzed depletion efficiency and cell yield in 200 procedures performed in the last 3 years at our center. Donors underwent CD34 +   hematopoietic stem cell (HSC) peripheral blood mobilization with granulocyte colony-stimulating factor (G-CSF). Poor CD34 +  cell mobilizers (48 of 189, 25%) received plerixafor in addition to G-CSF. Aphereses containing a median of 52.5 × 10 9 nucleated cells and 494 × 10 6 CD34 +  HSC were manipulated using the CliniMACS device. In comparison to the initial product, αβ T cell depletion produced a median 4.1-log reduction (range, 3.1 to 5.5) and B cell depletion led to a median 3.4-log reduction (range, 2.0 to 4.7). Graft products contained a median of 18.5 × 10 6 CD34 +  HSC/kg recipient body weight, with median values of residual αβ T cells and B cells of 29 × 10 3 /kg and 33 × 10 3 /kg, respectively. Depletion efficiency monitored at 6-month intervals demonstrated steady performance, while improved recovery of CD34 +  cells was observed after the first year (P = .0005). These data indicate that αβ T cell and B cell depletion of HSC grafts from HLA-haploidentical donors was efficient and reproducible. Copyright © 2016 The American Society for Blood and Marrow

  14. T cell clones which share T cell receptor epitopes differ in phenotype, function and specificity

    NARCIS (Netherlands)

    Yssel, H.; Blanchard, D.; Boylston, A.; de Vries, J. E.; Spits, H.

    1986-01-01

    Recently, we described a monoclonal antibody (3D6) that reacts with the T cell receptor (Ti) of the T leukemic cell line HPB-ALL and that cross-reacts with 2-10% of the T cells of normal healthy individuals. In this study we report the establishment of T cell clones that are 3D6+ but that differ in

  15. Early Experience With CliniMACS Prodigy CCS (IFN-gamma) System in Selection of Virus-specific T Cells From Third-party Donors for Pediatric Patients With Severe Viral Infections After Hematopoietic Stem Cell Transplantation.

    Science.gov (United States)

    Kállay, Krisztián; Kassa, Csaba; Réti, Marienn; Karászi, Éva; Sinkó, János; Goda, Vera; Stréhn, Anita; Csordás, Katalin; Horváth, Orsolya; Szederjesi, Attila; Tasnády, Szabolcs; Hardi, Apor; Kriván, Gergely

    2018-04-01

    Viral reactivation is a frequent complication of allogeneic hematopoietic stem cell transplantation especially in children. For refractory cases, rapid virus-specific T-cell therapy would be ideally implemented within a few days. Over the course of a year in our pediatric cohort of 43 allogeneic transplantation, 9 patients fulfilled criteria for virus-specific T-cell therapy. Viral infections were due to cytomegalovirus (CMV) in 3, Epstein-Barr virus (EBV) in 2, and adenovirus (AdV) in 1 case, whereas >1 virus was detected in 3 cases. Viral diseases necessitating a T-cell therapy were CMV pneumonitis and colitis, AdV enteritis and cystitis, and EBV-induced posttransplantation lymphoproliferative disease. Cells were produced by the CliniMACS Prodigy CCS (IFN-gamma) System within 24 hours after mononuclear leukapheresis. Eight patients became completely asymptomatic, whereas 7 also cleared the virus. Six patients are alive without viral illness or sequelae demonstrating viral DNA clearance in peripheral blood with a median follow-up of 535 (350-786) days. One patient with CMV pneumonitis died of respiratory insufficiency. In 2 cases the viral illness improved or cleared, however, the patients died of invasive aspergillosis. No cases of graft-versus-host disease, rejection, organ toxicity, or recurrent infection were noticed. Virus-specific T-cell therapy implemented by the CliniMACS Prodigy CCS (IFN-gamma) System is an automated, fast, safe, and probably effective way to control resistant viral diseases after pediatric hematopoietic stem cell transplantation.

  16. The integration of signalling and the spatial organization of the T cell synapse

    Directory of Open Access Journals (Sweden)

    Jeremie eRossy

    2012-11-01

    Full Text Available Engagement of the T cell antigen receptor (TCR triggers signalling pathways that lead to T cell selection, differentiation and clonal expansion. Superimposed onto the biochemical network is a spatial organization that describes individual receptor molecules, dimers, oligomers and higher order structures. Here we review recent finding about TCR organization in naïve and memory T cells. A key question that has emerged is how antigen-TCR interactions encode spatial information to direct T cell activation and differentiation. Single molecule super-resolution microscopy may become an important tool in decoding receptor organization at the molecular level.

  17. CAR T Cell Therapy for Glioblastoma: Recent Clinical Advances and Future Challenges.

    Science.gov (United States)

    Bagley, Stephen J; Desai, Arati S; Linette, Gerald P; June, Carl H; O'Rourke, Donald M

    2018-03-02

    In patients with certain hematologic malignancies, the use of autologous T cells genetically modified to express chimeric antigen receptors (CARs) has led to unprecedented clinical responses. Although progress in solid tumors has been elusive, recent clinical studies have demonstrated the feasibility and safety of CAR T cell therapy for glioblastoma. In addition, despite formidable barriers to T cell localization and effector function in glioblastoma, signs of efficacy have been observed in select patients. In this review, we begin with a discussion of established obstacles to systemic therapy in glioblastoma and how these may be overcome by CAR T cells. We continue with a summary of previously published CAR T cell trials in GBM, and end by outlining the key therapeutic challenges associated with the use of CAR T cells in this disease.

  18. Extracellular NGFR Spacers Allow Efficient Tracking and Enrichment of Fully Functional CAR-T Cells Co-Expressing a Suicide Gene.

    Science.gov (United States)

    Casucci, Monica; Falcone, Laura; Camisa, Barbara; Norelli, Margherita; Porcellini, Simona; Stornaiuolo, Anna; Ciceri, Fabio; Traversari, Catia; Bordignon, Claudio; Bonini, Chiara; Bondanza, Attilio

    2018-01-01

    Chimeric antigen receptor (CAR)-T cell immunotherapy is at the forefront of innovative cancer therapeutics. However, lack of standardization of cellular products within the same clinical trial and lack of harmonization between different trials have hindered the clear identification of efficacy and safety determinants that should be unveiled in order to advance the field. With the aim of facilitating the isolation and in vivo tracking of CAR-T cells, we here propose the inclusion within the CAR molecule of a novel extracellular spacer based on the low-affinity nerve-growth-factor receptor (NGFR). We screened four different spacer designs using as target antigen the CD44 isoform variant 6 (CD44v6). We successfully generated NGFR-spaced CD44v6 CAR-T cells that could be efficiently enriched with clinical-grade immuno-magnetic beads without negative consequences on subsequent expansion, immuno-phenotype, in vitro antitumor reactivity, and conditional ablation when co-expressing a suicide gene. Most importantly, these cells could be tracked with anti-NGFR monoclonal antibodies in NSG mice, where they expanded, persisted, and exerted potent antitumor effects against both high leukemia and myeloma burdens. Similar results were obtained with NGFR-enriched CAR-T cells specific for CD19 or CEA, suggesting the universality of this strategy. In conclusion, we have demonstrated that the incorporation of the NGFR marker gene within the CAR sequence allows for a single molecule to simultaneously work as a therapeutic and selection/tracking gene. Looking ahead, NGFR spacer enrichment might allow good manufacturing procedures-manufacturing of standardized CAR-T cell products with high therapeutic potential, which could be harmonized in different clinical trials and used in combination with a suicide gene for future application in the allogeneic setting.

  19. Extracellular NGFR Spacers Allow Efficient Tracking and Enrichment of Fully Functional CAR-T Cells Co-Expressing a Suicide Gene

    Directory of Open Access Journals (Sweden)

    Monica Casucci

    2018-03-01

    Full Text Available Chimeric antigen receptor (CAR-T cell immunotherapy is at the forefront of innovative cancer therapeutics. However, lack of standardization of cellular products within the same clinical trial and lack of harmonization between different trials have hindered the clear identification of efficacy and safety determinants that should be unveiled in order to advance the field. With the aim of facilitating the isolation and in vivo tracking of CAR-T cells, we here propose the inclusion within the CAR molecule of a novel extracellular spacer based on the low-affinity nerve-growth-factor receptor (NGFR. We screened four different spacer designs using as target antigen the CD44 isoform variant 6 (CD44v6. We successfully generated NGFR-spaced CD44v6 CAR-T cells that could be efficiently enriched with clinical-grade immuno-magnetic beads without negative consequences on subsequent expansion, immuno-phenotype, in vitro antitumor reactivity, and conditional ablation when co-expressing a suicide gene. Most importantly, these cells could be tracked with anti-NGFR monoclonal antibodies in NSG mice, where they expanded, persisted, and exerted potent antitumor effects against both high leukemia and myeloma burdens. Similar results were obtained with NGFR-enriched CAR-T cells specific for CD19 or CEA, suggesting the universality of this strategy. In conclusion, we have demonstrated that the incorporation of the NGFR marker gene within the CAR sequence allows for a single molecule to simultaneously work as a therapeutic and selection/tracking gene. Looking ahead, NGFR spacer enrichment might allow good manufacturing procedures-manufacturing of standardized CAR-T cell products with high therapeutic potential, which could be harmonized in different clinical trials and used in combination with a suicide gene for future application in the allogeneic setting.

  20. Extracellular NGFR Spacers Allow Efficient Tracking and Enrichment of Fully Functional CAR-T Cells Co-Expressing a Suicide Gene

    Science.gov (United States)

    Casucci, Monica; Falcone, Laura; Camisa, Barbara; Norelli, Margherita; Porcellini, Simona; Stornaiuolo, Anna; Ciceri, Fabio; Traversari, Catia; Bordignon, Claudio; Bonini, Chiara; Bondanza, Attilio

    2018-01-01

    Chimeric antigen receptor (CAR)-T cell immunotherapy is at the forefront of innovative cancer therapeutics. However, lack of standardization of cellular products within the same clinical trial and lack of harmonization between different trials have hindered the clear identification of efficacy and safety determinants that should be unveiled in order to advance the field. With the aim of facilitating the isolation and in vivo tracking of CAR-T cells, we here propose the inclusion within the CAR molecule of a novel extracellular spacer based on the low-affinity nerve-growth-factor receptor (NGFR). We screened four different spacer designs using as target antigen the CD44 isoform variant 6 (CD44v6). We successfully generated NGFR-spaced CD44v6 CAR-T cells that could be efficiently enriched with clinical-grade immuno-magnetic beads without negative consequences on subsequent expansion, immuno-phenotype, in vitro antitumor reactivity, and conditional ablation when co-expressing a suicide gene. Most importantly, these cells could be tracked with anti-NGFR monoclonal antibodies in NSG mice, where they expanded, persisted, and exerted potent antitumor effects against both high leukemia and myeloma burdens. Similar results were obtained with NGFR-enriched CAR-T cells specific for CD19 or CEA, suggesting the universality of this strategy. In conclusion, we have demonstrated that the incorporation of the NGFR marker gene within the CAR sequence allows for a single molecule to simultaneously work as a therapeutic and selection/tracking gene. Looking ahead, NGFR spacer enrichment might allow good manufacturing procedures-manufacturing of standardized CAR-T cell products with high therapeutic potential, which could be harmonized in different clinical trials and used in combination with a suicide gene for future application in the allogeneic setting. PMID:29619024

  1. Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides.

    Science.gov (United States)

    Mukhopadhya, Indrani; Murray, Graeme I; Duncan, Linda; Yuecel, Raif; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

    2016-09-06

    CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

  2. Tolerance without clonal expansion: self-antigen-expressing B cells program self-reactive T cells for future deletion.

    Science.gov (United States)

    Frommer, Friederike; Heinen, Tobias J A J; Wunderlich, F Thomas; Yogev, Nir; Buch, Thorsten; Roers, Axel; Bettelli, Estelle; Müller, Werner; Anderton, Stephen M; Waisman, Ari

    2008-10-15

    B cells have been shown in various animal models to induce immunological tolerance leading to reduced immune responses and protection from autoimmunity. We show that interaction of B cells with naive T cells results in T cell triggering accompanied by the expression of negative costimulatory molecules such as PD-1, CTLA-4, B and T lymphocyte attenuator, and CD5. Following interaction with B cells, T cells were not induced to proliferate, in a process that was dependent on their expression of PD-1 and CTLA-4, but not CD5. In contrast, the T cells became sensitive to Ag-induced cell death. Our results demonstrate that B cells participate in the homeostasis of the immune system by ablation of conventional self-reactive T cells.

  3. Meningeal mast cell-T cell crosstalk regulates T cell encephalitogenicity.

    Science.gov (United States)

    Russi, Abigail E; Walker-Caulfield, Margaret E; Guo, Yong; Lucchinetti, Claudia F; Brown, Melissa A

    2016-09-01

    GM-CSF is a cytokine produced by T helper (Th) cells that plays an essential role in orchestrating neuroinflammation in experimental autoimmune encephalomyelitis, a rodent model of multiple sclerosis. Yet where and how Th cells acquire GM-CSF expression is unknown. In this study we identify mast cells in the meninges, tripartite tissues surrounding the brain and spinal cord, as important contributors to antigen-specific Th cell accumulation and GM-CSF expression. In the absence of mast cells, Th cells do not accumulate in the meninges nor produce GM-CSF. Mast cell-T cell co-culture experiments and selective mast cell reconstitution of the meninges of mast cell-deficient mice reveal that resident meningeal mast cells are an early source of caspase-1-dependent IL-1β that licenses Th cells to produce GM-CSF and become encephalitogenic. We also provide evidence of mast cell-T cell co-localization in the meninges and CNS of recently diagnosed acute MS patients indicating similar interactions may occur in human demyelinating disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Biomarkers on melanoma patient T Cells associated with ipilimumab treatment

    Directory of Open Access Journals (Sweden)

    Wang Wenshi

    2012-07-01

    Full Text Available Abstract Background Ipilimumab induces long-lasting clinical responses in a minority of patients with metastatic melanoma. To better understand the mechanism(s of action and to identify novel biomarkers associated with the clinical benefit and toxicity of ipilimumab, baseline characteristics and changes in CD4+ and CD8+ T cells from melanoma patients receiving ipilimumab were characterized by gene profiling and flow cytometry. Methods Microarray analysis of flow-cytometry purified CD4+ and CD8+ T cells was employed to assess gene profiling changes induced by ipilimumab. Selected molecules were further investigated by flow cytometry on pre, 3-month and 6-month post-treatment specimens. Results Ipilimumab up-regulated Ki67 and ICOS on CD4+ and CD8+ cells at both 3- and 6-month post ipilimumab (p ≤ 0.001, decreased CCR7 and CD25 on CD8+ at 3-month post ipilimumab (p ≤ 0.02, and increased Gata3 in CD4+ and CD8+ cells at 6-month post ipilimumab (p ≤ 0.001. Increased EOMES+CD8+, GranzymeB+EOMES+CD8+ and decreased Ki67+EOMES+CD4+ T cells at 6 months were significantly associated with relapse (all p ≤ 0.03. Decreased Ki67+CD8+ T cells were significantly associated with the development of irAE (p = 0.02. At baseline, low Ki67+EOMES+CD8+ T cells were associated with relapse (p ≤ 0.001, and low Ki67+EOMES+CD4+ T cells were associated with irAE (p ≤ 0.008. Conclusions Up-regulation of proliferation and activation signals in CD4+ and CD8+ T cells were pharmacodynamic markers for ipilimumab. Ki67+EOMES+CD8+ and Ki67+EOMES+CD4+T cells at baseline merit further testing as biomarkers associated with outcome and irAEs, respectively.

  5. Selective ablation of Copper-Indium-Diselenide solar cells monitored by laser-induced breakdown spectroscopy and classification methods

    Energy Technology Data Exchange (ETDEWEB)

    Diego-Vallejo, David [Technische Universität Berlin, Institute of Optics and Atomic Physics, Straße des 17, Juni 135, 10623 Berlin (Germany); Laser- und Medizin- Technologie Berlin GmbH (LMTB), Applied Laser Technology, Fabeckstr. 60-62, 14195 Berlin (Germany); Ashkenasi, David, E-mail: d.ashkenasi@lmtb.de [Laser- und Medizin- Technologie Berlin GmbH (LMTB), Applied Laser Technology, Fabeckstr. 60-62, 14195 Berlin (Germany); Lemke, Andreas [Laser- und Medizin- Technologie Berlin GmbH (LMTB), Applied Laser Technology, Fabeckstr. 60-62, 14195 Berlin (Germany); Eichler, Hans Joachim [Technische Universität Berlin, Institute of Optics and Atomic Physics, Straße des 17, Juni 135, 10623 Berlin (Germany); Laser- und Medizin- Technologie Berlin GmbH (LMTB), Applied Laser Technology, Fabeckstr. 60-62, 14195 Berlin (Germany)

    2013-09-01

    Laser-induced breakdown spectroscopy (LIBS) and two classification methods, i.e. linear correlation and artificial neural networks (ANN), are used to monitor P1, P2 and P3 scribing steps of Copper-Indium-Diselenide (CIS) solar cells. Narrow channels featuring complete removal of desired layers with minimum damage on the underlying film are expected to enhance efficiency of solar cells. The monitoring technique is intended to determine that enough material has been removed to reach the desired layer based on the analysis of plasma emission acquired during multiple pass laser scribing. When successful selective scribing is achieved, a high degree of similarity between test and reference spectra has to be identified by classification methods in order to stop the scribing procedure and avoid damaging the bottom layer. Performance of linear correlation and artificial neural networks is compared and evaluated for two spectral bandwidths. By using experimentally determined combinations of classifier and analyzed spectral band for each step, classification performance achieves errors of 7, 1 and 4% for steps P1, P2 and P3, respectively. The feasibility of using plasma emission for the supervision of processing steps of solar cell manufacturing is demonstrated. This method has the potential to be implemented as an online monitoring procedure assisting the production of solar cells. - Highlights: • LIBS and two classification methods were used to monitor CIS solar cells processing. • Selective ablation of thin-film solar cells was improved with inspection system. • Customized classification method and analyzed spectral band enhanced performance.

  6. Cell-specific cre recombinase expression allows selective ablation of glutamate receptors from mouse horizontal cells.

    Directory of Open Access Journals (Sweden)

    Sebastian Ströh

    Full Text Available In the mouse retina, horizontal cells form an electrically coupled network and provide feedback signals to photoreceptors and feedforward signals to bipolar cells. Thereby, horizontal cells contribute to gain control at the first visual synapse and to the antagonistic organization of bipolar and ganglion cell receptive fields. However, the nature of horizontal cell output remains a matter of debate, just as the exact contribution of horizontal cells to center-surround antagonism. To facilitate studying horizontal cell function, we developed a knockin mouse line which allows ablating genes exclusively in horizontal cells. This knockin line expresses a Cre recombinase under the promoter of connexin57 (Cx57, a gap junction protein only expressed in horizontal cells. Consistently, in Cx57+/Cre mice, Cre recombinase is expressed in almost all horizontal cells (>99% and no other retinal neurons. To test Cre activity, we crossbred Cx57+/Cre mice with a mouse line in which exon 11 of the coding sequence for the ionotropic glutamate receptor subunit GluA4 was flanked by two loxP sites (GluA4fl/fl. In GluA4fl/fl:Cx57+/Cre mice, GluA4 immunoreactivity was significantly reduced (∼ 50% in the outer retina where horizontal cells receive photoreceptor inputs, confirming the functionality of the Cre/loxP system. Whole-cell patch-clamp recordings from isolated horizontal cell somata showed a reduction of glutamate-induced inward currents by ∼ 75%, suggesting that the GluA4 subunit plays a major role in mediating photoreceptor inputs. The persistent current in GluA4-deficient cells is mostly driven by AMPA and to a very small extent by kainate receptors as revealed by application of the AMPA receptor antagonist GYKI52466 and concanavalin A, a potentiator of kainate receptor-mediated currents. In summary, the Cx57+/Cre mouse line provides a versatile tool for studying horizontal cell function. GluA4fl/fl:Cx57+/Cre mice, in which horizontal cells receive less

  7. Cell-Specific Cre Recombinase Expression Allows Selective Ablation of Glutamate Receptors from Mouse Horizontal Cells

    Science.gov (United States)

    Janssen-Bienhold, Ulrike; Schultz, Konrad; Cimiotti, Kerstin; Weiler, Reto; Willecke, Klaus; Dedek, Karin

    2013-01-01

    In the mouse retina, horizontal cells form an electrically coupled network and provide feedback signals to photoreceptors and feedforward signals to bipolar cells. Thereby, horizontal cells contribute to gain control at the first visual synapse and to the antagonistic organization of bipolar and ganglion cell receptive fields. However, the nature of horizontal cell output remains a matter of debate, just as the exact contribution of horizontal cells to center-surround antagonism. To facilitate studying horizontal cell function, we developed a knockin mouse line which allows ablating genes exclusively in horizontal cells. This knockin line expresses a Cre recombinase under the promoter of connexin57 (Cx57), a gap junction protein only expressed in horizontal cells. Consistently, in Cx57+/Cre mice, Cre recombinase is expressed in almost all horizontal cells (>99%) and no other retinal neurons. To test Cre activity, we crossbred Cx57+/Cre mice with a mouse line in which exon 11 of the coding sequence for the ionotropic glutamate receptor subunit GluA4 was flanked by two loxP sites (GluA4fl/fl). In GluA4fl/fl:Cx57+/Cre mice, GluA4 immunoreactivity was significantly reduced (∼50%) in the outer retina where horizontal cells receive photoreceptor inputs, confirming the functionality of the Cre/loxP system. Whole-cell patch-clamp recordings from isolated horizontal cell somata showed a reduction of glutamate-induced inward currents by ∼75%, suggesting that the GluA4 subunit plays a major role in mediating photoreceptor inputs. The persistent current in GluA4-deficient cells is mostly driven by AMPA and to a very small extent by kainate receptors as revealed by application of the AMPA receptor antagonist GYKI52466 and concanavalin A, a potentiator of kainate receptor-mediated currents. In summary, the Cx57+/Cre mouse line provides a versatile tool for studying horizontal cell function. GluA4fl/fl:Cx57+/Cre mice, in which horizontal cells receive less excitatory input

  8. Leukemia -- Chronic T-Cell Lymphocytic

    Science.gov (United States)

    ... social workers, and patient advocates. Cancer.Net Guide Leukemia - Chronic T-Cell Lymphocytic Introduction Statistics Risk Factors Symptoms and Signs Diagnosis Stages Treatment Options About Clinical Trials Latest Research ...

  9. Surviving the crash: T-cell homeostasis

    Indian Academy of Sciences (India)

    TOSHIBA

    The formation of higher order apoptotic structures at the mitochondrion precedes cellular collapse dead. Tracking bax multimerization at mitochondria wildtype. Bax active -6A7. Nucleus – H33342. Apoptotic T-cells ...

  10. Cross–dressers turn on T cells

    OpenAIRE

    YEWDELL, JONATHAN W.; DOLAN, BRIAN P.

    2011-01-01

    Memory T cells remember viruses from previous infections, providing immunity by facilitating the killing of infected cells. For this, they exploit cross-dressing, the transfer of antigens between antigen-presenting cells.

  11. Targetless T cells in cancer immunotherapy

    DEFF Research Database (Denmark)

    thor Straten, Eivind Per; Garrido, Federico

    2016-01-01

    Attention has recently focused on new cancer immunotherapy protocols aiming to activate T cell mediated anti-tumor responses. To this end, administration of antibodies that target inhibitory molecules regulating T-cell cytotoxicity has achieved impressive clinical responses, as has adoptive cell...... infiltrate tumor tissues and destroy HLA class I positive tumor cells expressing the specific antigen. In fact, current progress in the field of cancer immune therapy is based on the capacity of T cells to kill cancer cells that present tumor antigen in the context on an HLA class I molecule. However......, it is also well established that cancer cells are often characterized by loss or down regulation of HLA class I molecules, documented in a variety of human tumors. Consequently, immune therapy building on CD8 T cells will be futile in patients harboring HLA class-I negative or deficient cancer cells...

  12. Dopamine, T cells and multiple sclerosis (MS).

    Science.gov (United States)

    Levite, Mia; Marino, Franca; Cosentino, Marco

    2017-05-01

    Dopamine is a key neurotransmitter that induces critical effects in the nervous system and in many peripheral organs, via 5 dopamine receptors (DRs): D1R-D5R. Dopamine also induces many direct and very potent effects on many DR-expressing immune cells, primarily T cells and dendritic cells. In this review, we focus only on dopamine receptors, effects and production in T cells. Dopamine by itself (at an optimal concentration of~0.1 nM) induces multiple function of resting normal human T cells, among them: T cell adhesion, chemotactic migration, homing, cytokine secretion and others. Interestingly, dopamine activates resting effector T cells (Teffs), but suppresses regulatory T cells (Tregs), and both effects lead eventually to Teff activation. Dopamine-induced effects on T cells are dynamic, context-sensitive and determined by the: T cell activation state, T cell type, DR type, and dopamine concentration. Dopamine itself, and also few dopaminergic molecules/ drugs that are in clinical use for cardiac, neurological and other non-immune indications, have direct effects on human T cells (summarized in this review). These dopaminergic drugs include: dopamine = intropin, L-DOPA, bromocriptine, pramipexole, pergolide, haloperidol, pimozide, and amantadine. Other dopaminergic drugs were not yet tested for their direct effects on T cells. Extensive evidence in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) show dopaminergic dysregulations in T cells in these diseases: D1-like DRs are decreased in Teffs of MS patients, and dopamine does not affect these cells. In contrast, D1-like DRs are increased in Tregs of MS patients, possibly causing functional Treg impairment in MS. Treatment of MS patients with interferon β (IFN-β) increases D1-like DRs and decreases D2-like DRs in Teffs, decreases D1-like DRs in Tregs, and most important: restores responsiveness of patient's Teffs to dopamine. DR agonists and antagonists confer some benefits in

  13. CD4+ T cell effects on CD8+ T cell location defined using bioluminescence.

    Directory of Open Access Journals (Sweden)

    Mitra Azadniv

    2011-01-01

    Full Text Available T lymphocytes of the CD8+ class are critical in delivering cytotoxic function and in controlling viral and intracellular infections. These cells are "helped" by T lymphocytes of the CD4+ class, which facilitate their activation, clonal expansion, full differentiation and the persistence of memory. In this study we investigated the impact of CD4+ T cells on the location of CD8+ T cells, using antibody-mediated CD4+ T cell depletion and imaging the antigen-driven redistribution of bioluminescent CD8+ T cells in living mice. We documented that CD4+ T cells influence the biodistribution of CD8+ T cells, favoring their localization to abdominal lymph nodes. Flow cytometric analysis revealed that this was associated with an increase in the expression of specific integrins. The presence of CD4+ T cells at the time of initial CD8+ T cell activation also influences their biodistribution in the memory phase. Based on these results, we propose the model that one of the functions of CD4+ T cell "help" is to program the homing potential of CD8+ T cells.

  14. Biogenesis and function of T cell-derived exosomes

    Directory of Open Access Journals (Sweden)

    Miguel Angel Alonso

    2016-08-01

    Full Text Available Exosomes are a particular type of extracellular vesicle, characterized by their endosomal origin as intraluminal vesicles present in large endosomes with a multivesicular structure. After these endosomes fuse with the plasma membrane, exosomes are secreted into the extracellular space. The ability of exosomes to carry and selectively deliver bioactive molecules (e.g., lipids, proteins and nucleic acids confers on them the capacity to modulate the activity of receptor cells, even if these cells are located in distant tissues or organs. Since exosomal cargo depends on cell type, a detailed understanding of the mechanisms that regulate the biochemical composition of exosomes is fundamental to a comprehensive view of exosome function. Here, we review the latest advances concerning exosome function and biogenesis in T cells, with particular focus on the mechanism of protein sorting at multivesicular endosomes. Exosomes secreted by specific T-cell subsets can modulate the activity of immune cells, including other T-cell subsets. Ceramide, tetraspanins and MAL have been revealed to be important in exosome biogenesis by T cells. These molecules, therefore, constitute potential molecular targets for artificially modulating exosome production and, hence, the immune response for therapeutic purposes.

  15. Malaria drives T cells to exhaustion

    Directory of Open Access Journals (Sweden)

    Michelle N Wykes

    2014-05-01

    Full Text Available Malaria is a significant global burden but after >30 years of effort there is no vaccine on the market. While the complex life cycle of the parasite presents several challenges, many years of research have also identified several mechanisms of immune evasion by Plasmodium spp.. Recent research on malaria, has investigated the Programmed cell death-1 (PD-1 pathway which mediates exhaustion of T cells, characterized by poor effector functions and recall responses and in some cases loss of the cells by apoptosis. Such studies have shown exhaustion of CD4+ T cells and an unappreciated role for CD8+ T cells in promoting sterile immunity against blood stage malaria. This is because PD-1 mediates up to a 95% reduction in numbers and functional capacity of parasite-specific CD8+ T cells, thus masking their role in protection. The role of T cell exhaustion during malaria provides an explanation for the absence of sterile immunity following the clearance of acute disease which will be relevant to future malaria-vaccine design and suggests the need for novel therapeutic solutions. This review will thus examine the role of PD-1-mediated T cell exhaustion in preventing lasting immunity against malaria.

  16. Endogenous T-Cell Therapy: Clinical Experience.

    Science.gov (United States)

    Yee, Cassian; Lizee, Greg; Schueneman, Aaron J

    2015-01-01

    Adoptive cellular therapy represents a robust means of augmenting the tumor-reactive effector population in patients with cancer by adoptive transfer of ex vivo expanded T cells. Three approaches have been developed to achieve this goal: the use of tumor-infiltrating lymphocytes or tumor-infiltrating lymphocytess extracted from patient biopsy material; the redirected engineering of lymphocytes using vectors expressing a chimeric antigen receptor and T-cell receptor; and third, the isolation and expansion of often low-frequency endogenous T cells (ETCs) reactive to tumor antigens from the peripheral blood of patients. This last form of adoptive transfer of T cells, known as ETC therapy, requires specialized methods to isolate and expand from peripheral blood the very low-frequency tumor-reactive T cells, methods that have been developed over the last 2 decades, to the point where such an approach may be broadly applicable not only for the treatment of melanoma but also for that of other solid tumor malignancies. One compelling feature of ETC is the ability to rapidly deploy clinical trials following identification of a tumor-associated target epitope, a feature that may be exploited to develop personalized antigen-specific T-cell therapy for patients with almost any solid tumor. With a well-validated antigen discovery pipeline in place, clinical studies combining ETC with agents that modulate the immune microenvironment can be developed that will transform ETC into a feasible treatment modality.

  17. Aberrant phenotypes in peripheral T cell lymphomas.

    Science.gov (United States)

    Hastrup, N; Ralfkiaer, E; Pallesen, G

    1989-01-01

    Seventy six peripheral T cell lymphomas were examined immunohistologically to test their reactivity with a panel of monoclonal antibodies against 11 T cell associated antigens (CD1-8, CD27, UCHL1, and the T cell antigen receptor). Sixty two (82%) lymphomas showed aberrant phenotypes, and four main categories were distinguished as follows: (i) lack of one or several pan-T cell antigens (49, 64% of the cases); (ii) loss of both the CD4 and CD8 antigens (11, 15% of the cases); (iii) coexpression of the CD4 and CD8 antigens (13, 17% of the cases); and (iv) expression of the CD1 antigen (eight, 11% of the cases). No correlation was seen between the occurrence of aberrant phenotypes and the histological subtype. It is concluded that the demonstration of an aberrant phenotype is a valuable supplement to histological assessment in the diagnosis of peripheral T cell lymphomas. It is recommended that the panel of monoclonal antibodies against T cell differentiation antigens should be fairly large, as apparently any antigen may be lost in the process of malignant transformation. Images Figure PMID:2469701

  18. Presentation of an immunodominant immediate-early CD8+ T cell epitope resists human cytomegalovirus immunoevasion.

    Directory of Open Access Journals (Sweden)

    Stefanie Ameres

    Full Text Available Control of human cytomegalovirus (HCMV depends on CD8+ T cell responses that are shaped by an individual's repertoire of MHC molecules. MHC class I presentation is modulated by a set of HCMV-encoded proteins. Here we show that HCMV immunoevasins differentially impair T cell recognition of epitopes from the same viral antigen, immediate-early 1 (IE-1, that are presented by different MHC class I allotypes. In the presence of immunoevasins, HLA-A- and HLA-B-restricted T cell clones were ineffective, but HLA-C*0702-restricted T cell clones recognized and killed infected cells. Resistance of HLA-C*0702 to viral immunoevasins US2 and US11 was mediated by the alpha3 domain and C-terminal region of the HLA heavy chain. In healthy donors, HLA-C*0702-restricted T cells dominated the T cell response to IE-1. The same HLA-C allotype specifically protected infected cells from attack by NK cells that expressed a corresponding HLA-C-specific KIR. Thus, allotype-specific viral immunoevasion allows HCMV to escape control by NK cells and HLA-A- and HLA-B-restricted T cells, while the virus becomes selectively vulnerable to an immunodominant population of HLA-C-restricted T cells. Our work identifies a T cell population that may be of particular efficiency in HCMV-specific immunotherapy.

  19. Generation of mature T cells from human hematopoietic stem and progenitor cells in artificial thymic organoids.

    Science.gov (United States)

    Seet, Christopher S; He, Chongbin; Bethune, Michael T; Li, Suwen; Chick, Brent; Gschweng, Eric H; Zhu, Yuhua; Kim, Kenneth; Kohn, Donald B; Baltimore, David; Crooks, Gay M; Montel-Hagen, Amélie

    2017-05-01

    Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3 + TCR-αβ + single-positive CD8 + or CD4 + cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naive phenotypes, a diverse T cell receptor (TCR) repertoire and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen-specific cytotoxicity and near-complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ-encoding loci. ATOs provide a robust tool for studying human T cell differentiation and for the future development of stem-cell-based engineered T cell therapies.

  20. Regional Delivery of Chimeric Antigen Receptor (CAR) T-Cells for Cancer Therapy.

    Science.gov (United States)

    Sridhar, Praveen; Petrocca, Fabio

    2017-07-18

    Chimeric Antigen Receptor (CAR) T-cells are T-cells with recombinant receptors targeted to tumor antigens. CAR-T cell therapy has emerged as a mode of immunotherapy and is now being extensively explored in hematologic cancer. In contrast, CAR-T cell use in solid tumors has been hampered by multiple obstacles. Several approaches have been taken to circumvent these obstacles, including the regional delivery of CAR-T cells. Regional CAR-T cell delivery can theoretically compensate for poor T-cell trafficking and tumor antigen specificity while avoiding systemic toxicity associated with intravenous delivery. We reviewed completed clinical trials for the treatment of glioblastoma and metastatic colorectal cancer and examined the data in these studies for safety, efficacy, and potential advantages that regional delivery may confer over systemic delivery. Our appraisal of the available literature revealed that regional delivery of CAR-T cells in both glioblastoma and hepatic colorectal metastases was generally well tolerated and efficacious in select instances. We propose that the regional delivery of CAR-T cells is an area of potential growth in the solid tumor immunotherapy, and look towards future clinical trials in head and neck cancer, mesothelioma, and peritoneal carcinomatosis as the use of this technique expands.

  1. Regional Delivery of Chimeric Antigen Receptor (CAR T-Cells for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Praveen Sridhar

    2017-07-01

    Full Text Available Chimeric Antigen Receptor (CAR T-cells are T-cells with recombinant receptors targeted to tumor antigens. CAR-T cell therapy has emerged as a mode of immunotherapy and is now being extensively explored in hematologic cancer. In contrast, CAR-T cell use in solid tumors has been hampered by multiple obstacles. Several approaches have been taken to circumvent these obstacles, including the regional delivery of CAR-T cells. Regional CAR-T cell delivery can theoretically compensate for poor T-cell trafficking and tumor antigen specificity while avoiding systemic toxicity associated with intravenous delivery. We reviewed completed clinical trials for the treatment of glioblastoma and metastatic colorectal cancer and examined the data in these studies for safety, efficacy, and potential advantages that regional delivery may confer over systemic delivery. Our appraisal of the available literature revealed that regional delivery of CAR-T cells in both glioblastoma and hepatic colorectal metastases was generally well tolerated and efficacious in select instances. We propose that the regional delivery of CAR-T cells is an area of potential growth in the solid tumor immunotherapy, and look towards future clinical trials in head and neck cancer, mesothelioma, and peritoneal carcinomatosis as the use of this technique expands.

  2. FOXO3 regulates CD8 T cell memory by T cell-intrinsic mechanisms.

    Directory of Open Access Journals (Sweden)

    Jeremy A Sullivan

    2012-02-01

    Full Text Available CD8 T cell responses have three phases: expansion, contraction, and memory. Dynamic alterations in proliferation and apoptotic rates control CD8 T cell numbers at each phase, which in turn dictate the magnitude of CD8 T cell memory. Identification of signaling pathways that control CD8 T cell memory is incomplete. The PI3K/Akt signaling pathway controls cell growth in many cell types by modulating the activity of FOXO transcription factors. But the role of FOXOs in regulating CD8 T cell memory remains unknown. We show that phosphorylation of Akt, FOXO and mTOR in CD8 T cells occurs in a dynamic fashion in vivo during an acute viral infection. To elucidate the potentially dynamic role for FOXO3 in regulating homeostasis of activated CD8 T cells in lymphoid and non-lymphoid organs, we infected global and T cell-specific FOXO3-deficient mice with Lymphocytic Choriomeningitis Virus (LCMV. We found that FOXO3 deficiency induced a marked increase in the expansion of effector CD8 T cells, preferentially in the spleen, by T cell-intrinsic mechanisms. Mechanistically, the enhanced accumulation of proliferating CD8 T cells in FOXO3-deficient mice was not attributed to an augmented rate of cell division, but instead was linked to a reduction in cellular apoptosis. These data suggested that FOXO3 might inhibit accumulation of growth factor-deprived proliferating CD8 T cells by reducing their viability. By virtue of greater accumulation of memory precursor effector cells during expansion, the numbers of memory CD8 T cells were strikingly increased in the spleens of both global and T cell-specific FOXO3-deficient mice. The augmented CD8 T cell memory was durable, and FOXO3 deficiency did not perturb any of the qualitative attributes of memory T cells. In summary, we have identified FOXO3 as a critical regulator of CD8 T cell memory, and therapeutic modulation of FOXO3 might enhance vaccine-induced protective immunity against intracellular pathogens.

  3. A novel method to generate T-cell receptor-deficient chimeric antigen receptor T cells.

    Science.gov (United States)

    Kamiya, Takahiro; Wong, Desmond; Png, Yi Tian; Campana, Dario

    2018-03-13

    Practical methods are needed to increase the applicability and efficacy of chimeric antigen receptor (CAR) T-cell therapies. Using donor-derived CAR-T cells is attractive, but expression of endogenous T-cell receptors (TCRs) carries the risk for graft-versus-host-disease (GVHD). To remove surface TCRαβ, we combined an antibody-derived single-chain variable fragment specific for CD3ε with 21 different amino acid sequences predicted to retain it intracellularly. After transduction in T cells, several of these protein expression blockers (PEBLs) colocalized intracellularly with CD3ε, blocking surface CD3 and TCRαβ expression. In 25 experiments, median TCRαβ expression in T lymphocytes was reduced from 95.7% to 25.0%; CD3/TCRαβ cell depletion yielded virtually pure TCRαβ-negative T cells. Anti-CD3ε PEBLs abrogated TCRαβ-mediated signaling, without affecting immunophenotype or proliferation. In anti-CD3ε PEBL-T cells, expression of an anti-CD19-41BB-CD3ζ CAR induced cytokine secretion, long-term proliferation, and CD19 + leukemia cell killing, at rates meeting or exceeding those of CAR-T cells with normal CD3/TCRαβ expression. In immunodeficient mice, anti-CD3ε PEBL-T cells had markedly reduced GVHD potential; when transduced with anti-CD19 CAR, these T cells killed engrafted leukemic cells. PEBL blockade of surface CD3/TCRαβ expression is an effective tool to prepare allogeneic CAR-T cells. Combined PEBL and CAR expression can be achieved in a single-step procedure, is easily adaptable to current cell manufacturing protocols, and can be used to target other T-cell molecules to further enhance CAR-T-cell therapies. © 2018 by The American Society of Hematology.

  4. GLYCAN-DIRECTED CAR-T CELLS.

    Science.gov (United States)

    Steentoft, Catharina; Migliorini, Denis; King, Tiffany R; Mandel, Ulla; June, Carl H; Posey, Avery D

    2018-01-23

    Cancer immunotherapy is rapidly advancing in the treatment of a variety of hematopoietic cancers, including pediatric acute lymphoblastic leukemia and diffuse large B cell lymphoma, with chimeric antigen receptor (CAR)-T cells. CARs are genetically encoded artificial T cell receptors that combine the antigen specificity of an antibody with the machinery of T cell activation. However, implementation of CAR technology in the treatment of solid tumors has been progressing much slower. Solid tumors are characterized by a number of challenges that need to be overcome, including cellular heterogeneity, immunosuppressive tumor microenvironment (TME), and, in particular, few known cancer-specific targets. Post-translational modifications that differentially occur in malignant cells generate valid cell surface, cancer-specific targets for CAR-T cells. We previously demonstrated that CAR-T cells targeting an aberrant O-glycosylation of MUC1, a common cancer marker associated with changes in cell adhesion, tumor growth, and poor prognosis, could control malignant growth in mouse models. Here, we discuss the field of glycan-directed CAR-T cells and review the different classes of antibodies specific for glycan-targeting, including the generation of high affinity O-glycopeptide antibodies. Finally, we discuss historic and recently investigated glycan targets for CAR-T cells and provide our perspective on how targeting the tumor glycoproteome and/or glycome will improve CAR-T immunotherapy. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Supernatural T cells: genetic modification of T cells for cancer therapy.

    Science.gov (United States)

    Kershaw, Michael H; Teng, Michele W L; Smyth, Mark J; Darcy, Phillip K

    2005-12-01

    Immunotherapy is receiving much attention as a means of treating cancer, but complete, durable responses remain rare for most malignancies. The natural immune system seems to have limitations and deficiencies that might affect its ability to control malignant disease. An alternative to relying on endogenous components in the immune repertoire is to generate lymphocytes with abilities that are greater than those of natural T cells, through genetic modification to produce 'supernatural' T cells. This Review describes how such T cells can circumvent many of the barriers that are inherent in the tumour microenvironment while optimizing T-cell specificity, activation, homing and antitumour function.

  6. T-cell receptor transfer into human T cells with ecotropic retroviral vectors.

    Science.gov (United States)

    Koste, L; Beissert, T; Hoff, H; Pretsch, L; Türeci, Ö; Sahin, U

    2014-05-01

    Adoptive T-cell transfer for cancer immunotherapy requires genetic modification of T cells with recombinant T-cell receptors (TCRs). Amphotropic retroviral vectors (RVs) used for TCR transduction for this purpose are considered safe in principle. Despite this, TCR-coding and packaging vectors could theoretically recombine to produce replication competent vectors (RCVs), and transduced T-cell preparations must be proven free of RCV. To eliminate the need for RCV testing, we transduced human T cells with ecotropic RVs so potential RCV would be non-infectious for human cells. We show that transfection of synthetic messenger RNA encoding murine cationic amino-acid transporter 1 (mCAT-1), the receptor for murine retroviruses, enables efficient transient ecotropic transduction of human T cells. mCAT-1-dependent transduction was more efficient than amphotropic transduction performed in parallel, and preferentially targeted naive T cells. Moreover, we demonstrate that ecotropic TCR transduction results in antigen-specific restimulation of primary human T cells. Thus, ecotropic RVs represent a versatile, safe and potent tool to prepare T cells for the adoptive transfer.

  7. Selective ablation of dental calculus with a frequency-doubled Alexandrite laser

    Science.gov (United States)

    Rechmann, Peter; Hennig, Thomas

    1996-01-01

    The aim of the study was the selective removal of dental calculus by means of pulsed lasers. In a first approach the optical characteristics of subgingival calculus were calculated using fluorescence emission spectroscopy (excitation laser: N2-laser, wavelength 337 nm, pulse duration 4 ns). Subgingival calculus seems to absorb highly in the ultraviolet spectral region up to 420 nm. According to these measurements a frequency doubled Alexandrite-laser (wavelength 377 nm, pulse duration 100 ns, repetition rate 110 Hz) was used to irradiate calculus located on enamel, at the cementum enamel junction and on the root surface (located on dentin or on cementum). Irradiation was performed perpendicular to the root surface with a laser fluence of 1 Jcm-2. During the irradiation procedure an effective water cooling-system was engaged. Histological investigations were done on undecalcified sections. As a result, engaging low fluences allows a fast and strictly selective removal of subgingival calculus. Even more the investigations revealed that supragingival calculus can be removed in a strictly selective manner engaging a frequency doubled Alexandrite-laser. No adverse side effects to the surrounding tissues could be found.

  8. Decreased numbers of CD4+ naive and effector memory T cells, and CD8+ naïve T cells, are associated with trichloroethylene exposure

    Directory of Open Access Journals (Sweden)

    H Dean eHosgood

    2012-01-01

    Full Text Available Trichloroethylene (TCE is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE’s carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE’s early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4+ T cells, CD8+ T cells, natural killer (NK cells, and B cells were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors and/or lymphocyte survival. To explore which T lymphocyte subsets are affected, we investigated the effect of TCE exposure on the numbers of CD4+ naïve and memory T cells, CD8+ naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4+ and CD8+ naïve T cell counts were about 8% (p = 0.056 and 17% (p = 0.0002 lower, respectively, among exposed workers. CD4+ effector memory T cell counts were decreased by about 20% among TCE exposed workers compared to controls (p = 0.001. The selective targeting of TCE on CD8+ naïve and possibly CD4+ naive T cells, and CD4+ effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure.

  9. Regulatory T cell suppressive potency dictates the balance between bacterial proliferation and clearance during persistent Salmonella infection.

    Directory of Open Access Journals (Sweden)

    Tanner M Johanns

    2010-08-01

    Full Text Available The pathogenesis of persistent infection is dictated by the balance between opposing immune activation and suppression signals. Herein, virulent Salmonella was used to explore the role and potential importance of Foxp3-expressing regulatory T cells in dictating the natural progression of persistent bacterial infection. Two distinct phases of persistent Salmonella infection are identified. In the first 3-4 weeks after infection, progressively increasing bacterial burden was associated with delayed effector T cell activation. Reciprocally, at later time points after infection, reductions in bacterial burden were associated with robust effector T cell activation. Using Foxp3(GFP reporter mice for ex vivo isolation of regulatory T cells, we demonstrate that the dichotomy in infection tempo between early and late time points is directly paralleled by drastic changes in Foxp3(+ Treg suppressive potency. In complementary experiments using Foxp3(DTR mice, the significance of these shifts in Treg suppressive potency on infection outcome was verified by enumerating the relative impacts of regulatory T cell ablation on bacterial burden and effector T cell activation at early and late time points during persistent Salmonella infection. Moreover, Treg expression of CTLA-4 directly paralleled changes in suppressive potency, and the relative effects of Treg ablation could be largely recapitulated by CTLA-4 in vivo blockade. Together, these results demonstrate that dynamic regulation of Treg suppressive potency dictates the course of persistent bacterial infection.

  10. Markers of T Cell Senescence in Humans

    Directory of Open Access Journals (Sweden)

    Weili Xu

    2017-08-01

    Full Text Available Many countries are facing the aging of their population, and many more will face a similar obstacle in the near future, which could be a burden to many healthcare systems. Increased susceptibility to infections, cardiovascular and neurodegenerative disease, cancer as well as reduced efficacy of vaccination are important matters for researchers in the field of aging. As older adults show higher prevalence for a variety of diseases, this also implies higher risk of complications, including nosocomial infections, slower recovery and sequels that may reduce the autonomy and overall quality of life of older adults. The age-related effects on the immune system termed as “immunosenescence” can be exemplified by the reported hypo-responsiveness to influenza vaccination of the elderly. T cells, which belong to the adaptive arm of the immune system, have been extensively studied and the knowledge gathered enables a better understanding of how the immune system may be affected after acute/chronic infections and how this matters in the long run. In this review, we will focus on T cells and discuss the surface and molecular markers that are associated with T cell senescence. We will also look at the implications that senescent T cells could have on human health and diseases. Finally, we will discuss the benefits of having these markers for investigators and the future work that is needed to advance the field of T cell senescence markers.

  11. A proteomic view at T cell costimulation.

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    Rudolf Lichtenfels

    Full Text Available The "two-signal paradigm" in T cell activation predicts that the cooperation of "signal 1," provided by the T cell receptor (TCR through engagement of major histocompatility complex (MHC-presented peptide, with "signal 2″ provided by costimulatory molecules, the prototype of which is CD28, is required to induce T cell effector functions. While the individual signalling pathways are well understood, little is known about global changes in the proteome pattern during TCR/CD28-mediated activation. Therefore, comparative 2-DE-based proteome analyses of CD3(+ CD69(- resting T cells versus cells incubated with (i the agonistic anti-CD3 antibody OKT3 mimicking signal 1 in absence or presence of IL-2 and/or with (ii the agonistic antibody 15E8 triggering CD28-mediated signaling were performed. Differentially regulated spots were defined leading to the identification of proteins involved in the regulation of the metabolism, shaping and maintenance of the cytoskeleton and signal transduction. Representative members of the differentially expressed protein families, such as calmodulin (CALM, glyceraldehyde-3-phosphate dehydrogenase (GAPDH, L-lactate dehydrogenase (LDH, Rho GDP-dissociation inhibitor 2 (GDIR2, and platelet basic protein (CXCL7, were independently verified by flow cytometry. Data provide a detailed map of individual protein alterations at the global proteome level in response to TCR/CD28-mediated T cell activation.

  12. CD4+ Foxp3+ T-cells contribute to myocardial ischemia-reperfusion injury.

    Science.gov (United States)

    Mathes, Denise; Weirather, Johannes; Nordbeck, Peter; Arias-Loza, Anahi-Paula; Burkard, Matthias; Pachel, Christina; Kerkau, Thomas; Beyersdorf, Niklas; Frantz, Stefan; Hofmann, Ulrich

    2016-12-01

    The present study analyzed the effect of CD4 + Forkhead box protein 3 negative (Foxp3 - ) T-cells and Foxp3 + CD4 + T-cells on infarct size in a mouse myocardial ischemia-reperfusion model. We examined the infarct size as a fraction of the area-at-risk as primary study endpoint in mice after 30minutes of coronary ligation followed by 24hours of reperfusion. CD4 + T-cell deficient MHC-II KO mice showed smaller histologically determined infarct size (34.5±4.7% in MHCII KO versus 59.4±4.9% in wildtype (WT)) and better preserved ejection fraction determined by magnetic resonance tomography (56.9±2.8% in MHC II KO versus 39.0±4.2% in WT). MHC-II KO mice also displayed better microvascular perfusion than WT mice after 24hours of reperfusion. Also CD4 + T-cell sufficient OT-II mice, which express an in this context irrelevant T-cell receptor, revealed smaller infarct sizes compared to WT mice. However, MHC-II blocking anti-I-A/I-E antibody treatment was not able to reduce infarct size indicating that autoantigen recognition is not required for the activation of CD4 + T-cells during reperfusion. Flow-cytometric analysis also did not detect CD4 + T-cell activation in heart draining lymph nodes in response to 24hours of ischemia-reperfusion. Adoptive transfer of CD4 + T-cells in CD4 KO mice increased the infarct size only when including the Foxp3 + CD25 + subset. Depletion of CD4 + Foxp3 + T-cells in DEREG mice enabling specific conditional ablation of this subset by treatment with diphtheria toxin attenuated infarct size as compared to diphtheria toxin treated WT mice. CD4 + Foxp3 + T-cells enhance myocardial ischemia-reperfusion injury. CD4 + T-cells exert injurious effects without the need for prior activation by MHC-II restricted autoantigen recognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Suppression of pro-inflammatory T-cell responses by human mesothelial cells.

    Science.gov (United States)

    Lin, Chan-Yu; Kift-Morgan, Ann; Moser, Bernhard; Topley, Nicholas; Eberl, Matthias

    2013-07-01

    Human γδ T cells reactive to the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP) contribute to acute inflammatory responses. We have previously shown that peritoneal dialysis (PD)-associated infections with HMB-PP producing bacteria are characterized by locally elevated γδ T-cell frequencies and poorer clinical outcome compared with HMB-PP negative infections, implying that γδ T cells may be of diagnostic, prognostic and therapeutic value in acute disease. The regulation by local tissue cells of these potentially detrimental γδ T-cell responses remains to be investigated. Freshly isolated γδ or αβ T cells were cultured with primary mesothelial cells derived from omental tissue, or with mesothelial cell-conditioned medium. Stimulation of cytokine production and proliferation by peripheral T cells in response to HMB-PP or CD3/CD28 beads was assessed by flow cytometry. Resting mesothelial cells were potent suppressors of pro-inflammatory γδ T cells as well as CD4+ and CD8+ αβ T cells. The suppression of γδ T-cell responses was mediated through soluble factors released by primary mesothelial cells and could be counteracted by SB-431542, a selective inhibitor of TGF-β and activin signalling. Recombinant TGF-β1 but not activin-A mimicked the mesothelial cell-mediated suppression of γδ T-cell responses to HMB-PP. The present findings indicate an important regulatory function of mesothelial cells in the peritoneal cavity by dampening pro-inflammatory T-cell responses, which may help preserve the tissue integrity of the peritoneal membrane in the steady state and possibly during the resolution of acute inflammation.

  14. Reactive Oxygen Species and Their Implications on CD4+ T Cells in Type 1 Diabetes.

    Science.gov (United States)

    Previte, Dana M; Piganelli, Jon D

    2017-11-28

    Previous work has indicated that type 1 diabetes (T1D) pathology is highly driven by reactive oxygen species (ROS). One way in which ROS shape the autoimmune response demonstrated in T1D is by promoting CD4 + T cell activation and differentiation. As CD4 + T cells are a significant contributor to pancreatic β cell destruction in T1D, understanding how ROS impact their development, activation, and differentiation is critical. Recent Advances: CD4 + T cells themselves generate ROS via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression and electron transport chain activity. Moreover, T cells can also be exposed to exogenous ROS generated by other immune cells (e.g., macrophages and dendritic cells) and β cells. Genetically modified animals and ROS inhibitors have demonstrated that ROS blockade during activation results in CD4 + T cell hyporesponsiveness and reduced diabetes incidence. Critical Issues and Future Directions: Although the majority of studies with regard to T1D and CD4 + T cells have been done to examine the influence of redox on CD4 + T cell activation, this is not the only circumstance in which a T cell can be impacted by redox. ROS and redox have also been shown to play roles in CD4 + T cell-related tolerogenic mechanisms, including thymic selection and regulatory T cell-mediated suppression. However, the effect of these mechanisms with respect to T1D pathogenesis remains elusive. Therefore, pursuing these avenues may provide valuable insight into the global role of ROS and redox in autoreactive CD4 + T cell formation and function. Antioxid. Redox Signal. 00, 000-000.

  15. T cell recognition of breast cancer antigens

    DEFF Research Database (Denmark)

    Petersen, Nadia Viborg; Andersen, Sofie Ramskov; Andersen, Rikke Sick

    Recent studies are encouraging research of breast cancer immunogenicity to evaluate the applicability ofimmunotherapy as a treatment strategy. The epitope landscape in breast cancer is minimally described, thus it is necessary to identify T cell targets to develop immune mediated therapies.......This project investigates four proteins commonly upregulated in breast cancer and thus probable tumor associated antigens (TAAs). Aromatase, prolactin, NEK3, and PIAS3 contribute to increase growth, survival, and motility of malignant cells. Aspiring to uncover novel epitopes for cytotoxic T cells, a reverse...... recognition utilizing DNA barcode labeled MHC multimers to screen peripheral blood lymphocytes from breast cancer patients and healthy donor samples. Signif-icantly more TAA specific T cell responses were detected in breast cancer patients than healthy donors for both HLA-A*0201 (P

  16. γδ T cells in homeostasis and host defence of epithelial barrier tissues.

    Science.gov (United States)

    Nielsen, Morten M; Witherden, Deborah A; Havran, Wendy L

    2017-12-01

    Epithelial surfaces line the body and provide a crucial interface between the body and the external environment. Tissue-resident epithelial γδ T cells represent a major T cell population in the epithelial tissues and are ideally positioned to carry out barrier surveillance and aid in tissue homeostasis and repair. In this Review, we focus on the intraepithelial γδ T cell compartment of the two largest epithelial tissues in the body - namely, the epidermis and the intestine - and provide a comprehensive overview of the crucial contributions of intraepithelial γδ T cells to tissue integrity and repair, host homeostasis and protection in the context of the symbiotic relationship with the microbiome and during pathogen clearance. Finally, we describe epithelium-specific butyrophilin-like molecules and briefly review their emerging role in selectively shaping and regulating epidermal and intestinal γδ T cell repertoires.

  17. Malignant T cells express lymphotoxin alpha and drive endothelial activation in cutaneous T cell lymphoma

    DEFF Research Database (Denmark)

    Lauenborg, Britt; Christensen, Louise; Ralfkiaer, Ulrik

    2015-01-01

    Lymphotoxin α (LTα) plays a key role in the formation of lymphatic vasculature and secondary lymphoid structures. Cutaneous T cell lymphoma (CTCL) is the most common primary lymphoma of the skin and in advanced stages, malignant T cells spreads through the lymphatic to regional lymph nodes...

  18. Pharmacologic suppression of target cell recognition by engineered T cells expressing chimeric T-cell receptors.

    Science.gov (United States)

    Alvarez-Vallina, L; Yañez, R; Blanco, B; Gil, M; Russell, S J

    2000-04-01

    Adoptive therapy with autologous T cells expressing chimeric T-cell receptors (chTCRs) is of potential interest for the treatment of malignancy. To limit possible T-cell-mediated damage to normal tissues that weakly express the targeted tumor antigen (Ag), we have tested a strategy for the suppression of target cell recognition by engineered T cells. Jurkat T cells were transduced with an anti-hapten chTCR tinder the control of a tetracycline-suppressible promoter and were shown to respond to Ag-positive (hapten-coated) but not to Ag-negative target cells. The engineered T cells were then reacted with hapten-coated target cells at different effector to target cell ratios before and after exposure to tetracycline. When the engineered T cells were treated with tetracycline, expression of the chTCR was greatly decreased and recognition of the hapten-coated target cells was completely suppressed. Tetracycline-mediated suppression of target cell recognition by engineered T cells may be a useful strategy to limit the toxicity of the approach to cancer gene therapy.

  19. SAP is required for the development of innate phenotype in H2-M3-restricted CD8+ T cells1

    Science.gov (United States)

    Bediako, Yaw; Bian, Yao; Zhang, Hong; Cho, Hoonsik; Stein, Paul L.; Wang, Chyung-Ru

    2012-01-01

    H2-M3-restricted T cells have a pre-activated surface phenotype, rapidly expand and produce cytokines upon stimulation and as such, are classified as innate T cells. Unlike most innate T cells, M3-restricted T cells also express CD8αβ co-receptors and a diverse TCR repertoire: hallmarks of conventional MHC Ia-restricted CD8+ T cells. Although iNKT cells are also innate lymphocytes, they are selected exclusively on hematopoietic cells (HC), while M3-restricted T cells can be selected on either hematopoietic or thymic epithelial cells (TEC). Moreover, their phenotypes differ depending on what cells mediate their selection. Though there is a clear correlation between selection on HC and development of innate phenotype, the underlying mechanism remains unclear. SAP is required for the development of iNKT cells and mediates signals from SLAM receptors that are exclusively expressed on HC. Based on their dual selection pathway, M3-restricted T cells present a unique model for studying the development of innate T cell phenotype. Using both polyclonal and transgenic mouse models we demonstrate that while M3-restricted T cells are capable of developing in the absence of SAP, SAP is required for HC-mediated selection, development of pre-activated phenotype and heightened effector functions of M3-restricted T cells. These findings are significant because they directly demonstrate the need for SAP in HC-mediated acquisition of innate T cell phenotype and suggest that due to their SAP-dependent HC-mediated selection, M3-restricted T cells develop a pre-activated phenotype and an intrinsic ability to proliferate faster upon stimulation, allowing for an important role in the early response to infection. PMID:23041566

  20. Synthetic biology approaches to engineer T cells.

    Science.gov (United States)

    Wu, Chia-Yung; Rupp, Levi J; Roybal, Kole T; Lim, Wendell A

    2015-08-01

    There is rapidly growing interest in learning how to engineer immune cells, such as T lymphocytes, because of the potential of these engineered cells to be used for therapeutic applications such as the recognition and killing of cancer cells. At the same time, our knowhow and capability to logically engineer cellular behavior is growing rapidly with the development of synthetic biology. Here we describe how synthetic biology approaches are being used to rationally alter the behavior of T cells to optimize them for therapeutic functions. We also describe future developments that will be important in order to construct safe and precise T cell therapeutics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Peripheral T cell lymphoma: Not otherwise specified

    Directory of Open Access Journals (Sweden)

    Anusha H Pai

    2015-01-01

    Full Text Available Peripheral T cell lymphoma (PTCL is a heterogeneous group of hematological tumors originating from mature T cells, which constitutes less than 15% of all non-Hodgkins lymphomas in adults. Primary cutaneous PTCL-not otherwise specified (NOS represent a subgroup of PTCLs with no consistent immunophenotypic, genetic or clinical features. PTCL-NOS frequently has an aggressive course with a tendency for systemic involvement, however, a well-defined therapeutic and prognostic approach has not been outlined yet. We report a case of PTCL-NOS with multiple cutaneous lesions in a young adult male with an emphasis on the treatment modality used.

  2. Sex differences in T cells in hypertension.

    Science.gov (United States)

    Tipton, Ashlee J; Sullivan, Jennifer C

    2014-12-01

    Hypertension is a major risk factor for cardiovascular disease, stroke, and end-organ damage. There is a sex difference in blood pressure (BP) that begins in adolescence and continues into adulthood, in which men have a higher prevalence of hypertension compared with women until the sixth decade of life. Less than 50% of hypertensive adults in the United States manage to control their BP to recommended levels using current therapeutic options, and women are more likely than are men to have uncontrolled high BP. This, is despite the facts that more women compared with men are aware that they have hypertension and that women are more likely to seek treatment for the disease. Novel therapeutic targets need to be identified in both sexes to increase the percentage of hypertensive individuals with controlled BP. The purpose of this article was to review the available literature on the role of T cells in BP control in both sexes, and the potential therapeutic application/implications of targeting immune cells in hypertension. A search of PubMed was conducted to determine the impact of sex on T cell-mediated control of BP. The search terms included sex, gender, estrogen, testosterone, inflammation, T cells, T regulatory cells, Th17 cells, hypertension, and blood pressure. Additional data were included from our laboratory examinations of cytokine expression in the kidneys of male and female spontaneously hypertensive rats (SHRs) and differential gene expression in both the renal cortex and mesenteric arterial bed of male and female SHRs. There is a growing scientific literature base regarding the role of T cells in the pathogenesis of hypertension and BP control; however, the majority of these studies have been performed exclusively in males, despite the fact that both men and women develop hypertension. There is increasing evidence that although T cells also mediate BP in females, there are distinct differences in both the T-cell profile and the functional impact of sex

  3. T-cell responses in malaria

    DEFF Research Database (Denmark)

    Hviid, L; Jakobsen, P H; Abu-Zeid, Y A

    1992-01-01

    Malaria is caused by infection with protozoan parasites of the genus Plasmodium. It remains one of the most severe health problems in tropical regions of the world, and the rapid spread of resistance to drugs and insecticides has stimulated intensive research aimed at the development of a malaria...... vaccine. Despite this, no efficient operative vaccine is currently available. A large amount of information on T-cell responses to malaria antigens has been accumulated, concerning antigens derived from all stages of the parasite life cycle. The present review summarizes some of that information......, and discusses factors affecting the responses of T cells to malaria antigens....

  4. A Combined Omics Approach to Generate the Surface Atlas of Human Naive CD4+ T Cells during Early T-Cell Receptor Activation.

    Science.gov (United States)

    Graessel, Anke; Hauck, Stefanie M; von Toerne, Christine; Kloppmann, Edda; Goldberg, Tatyana; Koppensteiner, Herwig; Schindler, Michael; Knapp, Bettina; Krause, Linda; Dietz, Katharina; Schmidt-Weber, Carsten B; Suttner, Kathrin

    2015-08-01

    Naive CD4(+) T cells are the common precursors of multiple effector and memory T-cell subsets and possess a high plasticity in terms of differentiation potential. This stem-cell-like character is important for cell therapies aiming at regeneration of specific immunity. Cell surface proteins are crucial for recognition and response to signals mediated by other cells or environmental changes. Knowledge of cell surface proteins of human naive CD4(+) T cells and their changes during the early phase of T-cell activation is urgently needed for a guided differentiation of naive T cells and may support the selection of pluripotent cells for cell therapy. Periodate oxidation and aniline-catalyzed oxime ligation technology was applied with subsequent quantitative liquid chromatography-tandem MS to generate a data set describing the surface proteome of primary human naive CD4(+) T cells and to monitor dynamic changes during the early phase of activation. This led to the identification of 173 N-glycosylated surface proteins. To independently confirm the proteomic data set and to analyze the cell surface by an alternative technique a systematic phenotypic expression analysis of surface antigens via flow cytometry was performed. This screening expanded the previous data set, resulting in 229 surface proteins, which were expressed on naive unstimulated and activated CD4(+) T cells. Furthermore, we generated a surface expression atlas based on transcriptome data, experimental annotation, and predicted subcellular localization, and correlated the proteomics result with this transcriptional data set. This extensive surface atlas provides an overall naive CD4(+) T cell surface resource and will enable future studies aiming at a deeper understanding of mechanisms of T-cell biology allowing the identification of novel immune targets usable for the development of therapeutic treatments. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Chimeric Antigen Receptor T Cell (Car T Cell Therapy In Hematology

    Directory of Open Access Journals (Sweden)

    Pinar Ataca

    2015-12-01

    Full Text Available It is well demonstrated that immune system can control and eliminate cancer cells. Immune-mediated elimination of tumor cells has been discovered and is the basis of both cancer vaccines and cellular therapies including hematopoietic stem cell transplantation (HSCT. Adoptive T cell transfer has been improved to be more specific and potent and cause less off-target toxicities. Currently, there are two forms of engineered T cells being tested in clinical trials: T cell receptor (TCR and chimeric antigen receptor (CAR modified T cells. On July 1, 2014, the United States Food and Drug Administration granted ‘breakthrough therapy’ designation to anti-CD19 CAR T cell therapy. Many studies were conducted to evaluate the beneficiaries of this exciting and potent new treatment modality. This review summarizes the history of adoptive immunotherapy, adoptive immunotherapy using CARs, the CAR manufacturing process, preclinical-clinical studies, effectiveness and drawbacks of this strategy.

  6. Vitamin D controls T cell antigen receptor signaling and activation of human T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak-Wismann, Martin; Schjerling, Peter

    2010-01-01

    Phospholipase C (PLC) isozymes are key signaling proteins downstream of many extracellular stimuli. Here we show that naive human T cells had very low expression of PLC-gamma1 and that this correlated with low T cell antigen receptor (TCR) responsiveness in naive T cells. However, TCR triggering...... led to an upregulation of approximately 75-fold in PLC-gamma1 expression, which correlated with greater TCR responsiveness. Induction of PLC-gamma1 was dependent on vitamin D and expression of the vitamin D receptor (VDR). Naive T cells did not express VDR, but VDR expression was induced by TCR...... signaling via the alternative mitogen-activated protein kinase p38 pathway. Thus, initial TCR signaling via p38 leads to successive induction of VDR and PLC-gamma1, which are required for subsequent classical TCR signaling and T cell activation....

  7. Immunomodulation-accelerated neuronal regeneration following selective rod photoreceptor cell ablation in the zebrafish retina.

    Science.gov (United States)

    White, David T; Sengupta, Sumitra; Saxena, Meera T; Xu, Qingguo; Hanes, Justin; Ding, Ding; Ji, Hongkai; Mumm, Jeff S

    2017-05-02

    Müller glia (MG) function as inducible retinal stem cells in zebrafish, completely repairing the eye after damage. The innate immune system has recently been shown to promote tissue regeneration in which classic wound-healing responses predominate. However, regulatory roles for leukocytes during cellular regeneration-i.e., selective cell-loss paradigms akin to degenerative disease-are less well defined. To investigate possible roles innate immune cells play during retinal cell regeneration, we used intravital microscopy to visualize neutrophil, macrophage, and retinal microglia responses to induced rod photoreceptor apoptosis. Neutrophils displayed no reactivity to rod cell loss. Peripheral macrophage cells responded to rod cell loss, as evidenced by morphological transitions and increased migration, but did not enter the retina. Retinal microglia displayed multiple hallmarks of immune cell activation: increased migration, translocation to the photoreceptor cell layer, proliferation, and phagocytosis of dying cells. To test function during rod cell regeneration, we coablated microglia and rod cells or applied immune suppression and quantified the kinetics of ( i ) rod cell clearance, ( ii ) MG/progenitor cell proliferation, and ( iii ) rod cell replacement. Coablation and immune suppressants applied before cell loss caused delays in MG/progenitor proliferation rates and slowed the rate of rod cell replacement. Conversely, immune suppressants applied after cell loss had been initiated led to accelerated photoreceptor regeneration kinetics, possibly by promoting rapid resolution of an acute immune response. Our findings suggest that microglia control MG responsiveness to photoreceptor loss and support the development of immune-targeted therapeutic strategies for reversing cell loss associated with degenerative retinal conditions.

  8. Improving the efficacy and safety of engineered T cell therapy for cancer.

    Science.gov (United States)

    Shi, Huan; Liu, Lin; Wang, Zhehai

    2013-01-28

    Adoptive T-cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) is a powerful immunotherapeutics approach against metastatic melanoma. The success of TIL therapy has led to novel strategies for redirecting normal T cells to recognize tumor-associated antigens (TAAs) by genetically engineering tumor antigen-specific T cell receptors (TCRs) or chimeric antigen receptor (CAR) genes. In this manner, large numbers of antigen-specific T cells can be rapidly generated compared with the longer term expansion of TILs. Great efforts have been made to improve these approaches. Initial clinical studies have demonstrated that genetically engineered T cells can mediate tumor regression in vivo. In this review, we discuss the development of TCR and CAR gene-engineered T cells and the safety concerns surrounding the use of these T cells in patients. We highlight the importance of judicious selection of TAAs for modified T cell therapy and propose solutions for potential "on-target, off-organ" toxicity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Robust and Accurate Discrimination of Self/Non-Self Antigen Presentations by Regulatory T Cell Suppression.

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    Chikara Furusawa

    Full Text Available The immune response by T cells usually discriminates self and non-self antigens, even though the negative selection of self-reactive T cells is imperfect and a certain fraction of T cells can respond to self-antigens. In this study, we construct a simple mathematical model of T cell populations to analyze how such self/non-self discrimination is possible. The results demonstrate that the control of the immune response by regulatory T cells enables a robust and accurate discrimination of self and non-self antigens, even when there is a significant overlap between the affinity distribution of T cells to self and non-self antigens. Here, the number of regulatory T cells in the system acts as a global variable controlling the T cell population dynamics. The present study provides a basis for the development of a quantitative theory for self and non-self discrimination in the immune system and a possible strategy for its experimental verification.

  10. Robust and Accurate Discrimination of Self/Non-Self Antigen Presentations by Regulatory T Cell Suppression.

    Science.gov (United States)

    Furusawa, Chikara; Yamaguchi, Tomoyuki

    The immune response by T cells usually discriminates self and non-self antigens, even though the negative selection of self-reactive T cells is imperfect and a certain fraction of T cells can respond to self-antigens. In this study, we construct a simple mathematical model of T cell populations to analyze how such self/non-self discrimination is possible. The results demonstrate that the control of the immune response by regulatory T cells enables a robust and accurate discrimination of self and non-self antigens, even when there is a significant overlap between the affinity distribution of T cells to self and non-self antigens. Here, the number of regulatory T cells in the system acts as a global variable controlling the T cell population dynamics. The present study provides a basis for the development of a quantitative theory for self and non-self discrimination in the immune system and a possible strategy for its experimental verification.

  11. Cancer Immunotherapy Using CAR-T Cells: From the Research Bench to the Assembly Line.

    Science.gov (United States)

    Gomes-Silva, Diogo; Ramos, Carlos A

    2018-02-01

    The focus of cancer treatment has recently shifted toward targeted therapies, including immunotherapy, which allow better individualization of care and are hoped to increase the probability of success for patients. Specifically, T cells genetically modified to express chimeric antigen receptors (CARs; CAR-T cells) have generated exciting results. Recent clinical successes with this cutting-edge therapy have helped to push CAR-T cells toward approval for wider use. However, several limitations need to be addressed before the widespread use of CAR-T cells as a standard treatment. Here, a succinct background on adoptive T-cell therapy (ATCT)is given. A brief overview of the structure of CARs, how they are introduced into T cells, and how CAR-T cell expansion and selection is achieved in vitro is then presented. Some of the challenges in CAR design are discussed, as well as the difficulties that arise in large-scale CAR-T cell manufacture that will need to be addressed to achieve successful commercialization of this type of cell therapy. Finally, developments already on the horizon are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. T Cell Phenotype and T Cell Receptor Repertoire in Patients with Major Depressive Disorder

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    Kostas Patas

    2018-02-01

    Full Text Available While a link between inflammation and the development of neuropsychiatric disorders, including major depressive disorder (MDD is supported by a growing body of evidence, little is known about the contribution of aberrant adaptive immunity in this context. Here, we conducted in-depth characterization of T cell phenotype and T cell receptor (TCR repertoire in MDD. For this cross-sectional case–control study, we recruited antidepressant-free patients with MDD without any somatic or psychiatric comorbidities (n = 20, who were individually matched for sex, age, body mass index, and smoking status to a non-depressed control subject (n = 20. T cell phenotype and repertoire were interrogated using a combination of flow cytometry, gene expression analysis, and next generation sequencing. T cells from MDD patients showed significantly lower surface expression of the chemokine receptors CXCR3 and CCR6, which are known to be central to T cell differentiation and trafficking. In addition, we observed a shift within the CD4+ T cell compartment characterized by a higher frequency of CD4+CD25highCD127low/− cells and higher FOXP3 mRNA expression in purified CD4+ T cells obtained from patients with MDD. Finally, flow cytometry-based TCR Vβ repertoire analysis indicated a less diverse CD4+ T cell repertoire in MDD, which was corroborated by next generation sequencing of the TCR β chain CDR3 region. Overall, these results suggest that T cell phenotype and TCR utilization are skewed on several levels in patients with MDD. Our study identifies putative cellular and molecular signatures of dysregulated adaptive immunity and reinforces the notion that T cells are a pathophysiologically relevant cell population in this disorder.

  13. 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.

  14. Cardiac ablation

    Directory of Open Access Journals (Sweden)

    Kelly Ratheal

    2016-01-01

    Full Text Available Cardiac ablation is a procedure that uses either radiofrequency or cryothermal energy to destroy cells in the heart to terminate and/or prevent arrhythmias. The indications for cardiac catheter ablation include refractory, symptomatic arrhythmias, with more specific guidelines for atrial fibrillation in particular. The ablation procedure itself involves mapping the arrhythmia and destruction of the aberrant pathway in an effort to permanently prevent the arrhythmia. There are many types of arrhythmias, and they require individualized approaches to ablation based on their innately different electrical pathways. Ablation of arrhythmias, such as Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and atrial-fibrillation, is discussed in this review. Ablation has a high success rate overall and minimal complication rates, leading to improved quality of life in many patients.

  15. Exploiting the role of endogenous lymphoid-resident dendritic cells in the priming of NKT cells and CD8+ T cells to dendritic cell-based vaccines.

    Directory of Open Access Journals (Sweden)

    Troels R Petersen

    2011-03-01

    Full Text Available Transfer of antigen between antigen-presenting cells (APCs is potentially a physiologically relevant mechanism to spread antigen to cells with specialized stimulatory functions. Here we show that specific CD8+ T cell responses induced in response to intravenous administration of antigen-loaded bone marrow-derived dendritic cells (BM-DCs, were ablated in mice selectively depleted of endogenous lymphoid-resident langerin+ CD8α+ dendritic cells (DCs, suggesting that the antigen is transferred from the injected cells to resident APCs. In contrast, antigen-specific CD4+ T cells were primed predominantly by the injected BM-DCs, with only very weak contribution of resident APCs. Crucially, resident langerin+ CD8α+ DCs only contributed to the priming of CD8+ T cells in the presence of maturation stimuli such as intravenous injection of TLR ligands, or by loading the BM-DCs with the glycolipid α-galactosylceramide (α-GalCer to recruit the adjuvant activity of activated invariant natural killer-like T (iNKT cells. In fact, injection of α-GalCer-loaded CD1d-/- BM-DCs resulted in potent iNKT cell activation, suggesting that this glycolipid antigen can also be transferred to resident CD1d+ APCs. While iNKT cell activation per se was independent of langerin+ CD8α+ DCs, some iNKT cell-mediated activities were reduced, notably release of IL-12p70 and transactivation of NK cells. We conclude that both protein and glycolipid antigens can be exchanged between distinct DC species. These data suggest that the efficacy of DC-based vaccination strategies may be improved by the incorporation of a systemic maturation signal aimed to engage resident APCs in CD8+ T cell priming, and α-GalCer may be particularly well suited to this purpose.

  16. Selective ablation of the androgen receptor in mouse sertoli cells affects sertoli cell maturation, barrier formation and cytoskeletal development.

    Directory of Open Access Journals (Sweden)

    Ariane Willems

    2010-11-01

    Full Text Available The observation that mice with a selective ablation of the androgen receptor (AR in Sertoli cells (SC (SCARKO mice display a complete block in meiosis supports the contention that SC play a pivotal role in the control of germ cell development by androgens. To delineate the physiological and molecular mechanism responsible for this control, we compared tubular development in pubertal SCARKO mice and littermate controls. Particular attention was paid to differences in SC maturation, SC barrier formation and cytoskeletal organization and to the molecular mediators potentially involved. Functional analysis of SC barrier development by hypertonic perfusion and lanthanum permeation techniques and immunohistochemical analysis of junction formation showed that SCARKO mice still attempt to produce a barrier separating basal and adluminal compartment but that barrier formation is delayed and defective. Defective barrier formation was accompanied by disturbances in SC nuclear maturation (immature shape, absence of prominent, tripartite nucleoli and SC polarization (aberrant positioning of SC nuclei and cytoskeletal elements such as vimentin. Quantitative RT-PCR was used to study the transcript levels of genes potentially related to the described phenomena between day 8 and 35. Differences in the expression of SC genes known to play a role in junction formation could be shown from day 8 for Cldn11, from day 15 for Cldn3 and Espn, from day 20 for Cdh2 and Jam3 and from day 35 for ZO-1. Marked differences were also noted in the transcript levels of several genes that are also related to cell adhesion and cytoskeletal dynamics but that have not yet been studied in SC (Actn3, Ank3, Anxa9, Scin, Emb, Mpzl2. It is concluded that absence of a functional AR in SC impedes the remodeling of testicular tubules expected at the onset of spermatogenesis and interferes with the creation of the specific environment needed for germ cell development.

  17. Ablative skin resurfacing.

    Science.gov (United States)

    Agrawal, Nidhi; Smith, Greg; Heffelfinger, Ryan

    2014-02-01

    Ablative laser resurfacing has evolved as a safe and effective treatment for skin rejuvenation. Although traditional lasers were associated with significant thermal damage and lengthy recovery, advances in laser technology have improved safety profiles and reduced social downtime. CO2 lasers remain the gold standard of treatment, and fractional ablative devices capable of achieving remarkable clinical improvement with fewer side effects and shorter recovery times have made it a more practical option for patients. Although ablative resurfacing has become safer, careful patient selection and choice of suitable laser parameters are essential to minimize complications and optimize outcomes. This article describes the current modalities used in ablative laser skin resurfacing and examines their efficacy, indications, and possible side effects. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  18. APRIL modulates B and T cell immunity

    NARCIS (Netherlands)

    Stein, Jens V.; López-Fraga, Marta; Elustondo, Fernando A.; Carvalho-Pinto, Carla E.; Rodríguez, Dolores; Gómez-Caro, Ruth; de Jong, Joan; Martínez-A, Carlos; Medema, Jan Paul; Hahne, Michael

    2002-01-01

    The TNF-like ligands APRIL and BLyS are close relatives and share the capacity to bind the receptors TACI and BCMA. BLyS has been shown to play an important role in B cell homeostasis and autoimmunity, but the biological role of APRIL remains less well defined. Analysis of T cells revealed an

  19. Pregnancy persistently affects memory T cell populations

    NARCIS (Netherlands)

    Kieffer, Tom E. C.; Faas, Marijke M.; Scherjon, Sicco A.; Prins, Jelmer R.

    Pregnancy is an immune challenge to the maternal immune system. The effects of pregnancy on maternal immunity and particularly on memory T cells during and after pregnancy are not fully known. This observational study aims to show the short term and the long term effects of pregnancy on the

  20. Antigen-driven T-cell turnover

    NARCIS (Netherlands)

    Fraser, Christophe; Ferguson, Neil M.; de Wolf, Frank; Ghani, Azra C.; Garnett, Geoff P.; Anderson, Roy M.

    2002-01-01

    A mathematical model is developed to characterize the distribution of cell turnover rates within a population of T lymphocytes. Previous models of T-cell dynamics have assumed a constant uniform turnover rate; here we consider turnover in a cell pool subject to clonal proliferation in response to

  1. Genetic engineering with T cell receptors.

    Science.gov (United States)

    Zhang, Ling; Morgan, Richard A

    2012-06-01

    In the past two decades, human gene transfer research has been translated from a laboratory technology to clinical evaluation. The success of adoptive transfer of tumor-reactive lymphocytes to treat the patients with metastatic melanoma has led to new strategies to redirect normal T cells to recognize tumor antigens by genetic engineering with tumor antigen-specific T cell receptor (TCR) genes. This new strategy can generate large numbers of defined antigen-specific cells for therapeutic application. Much progress has been made to TCR gene transfer systems by optimizing gene expression and gene transfer protocols. Vector and protein modifications have enabled excellent expression of introduced TCR chains in human lymphocytes with reduced mis-pairing between the introduced and endogenous TCR chains. Initial clinical studies have demonstrated that TCR gene-engineered T cells could mediate tumor regression in vivo. In this review, we discuss the progress and prospects of TCR gene-engineered T cells as a therapeutic strategy for treating patients with melanoma and other cancers. Published by Elsevier B.V.

  2. Biomarkers in T cell therapy clinical trials

    Directory of Open Access Journals (Sweden)

    Kalos Michael

    2011-08-01

    Full Text Available Abstract T cell therapy represents an emerging and promising modality for the treatment of both infectious disease and cancer. Data from recent clinical trials have highlighted the potential for this therapeutic modality to effect potent anti-tumor activity. Biomarkers, operationally defined as biological parameters measured from patients that provide information about treatment impact, play a central role in the development of novel therapeutic agents. In the absence of information about primary clinical endpoints, biomarkers can provide critical insights that allow investigators to guide the clinical development of the candidate product. In the context of cell therapy trials, the definition of biomarkers can be extended to include a description of parameters of the cell product that are important for product bioactivity. This review will focus on biomarker studies as they relate to T cell therapy trials, and more specifically: i. An overview and description of categories and classes of biomarkers that are specifically relevant to T cell therapy trials, and ii. Insights into future directions and challenges for the appropriate development of biomarkers to evaluate both product bioactivity and treatment efficacy of T cell therapy trials.

  3. Engineered T cells for pancreatic cancer treatment

    Science.gov (United States)

    Katari, Usha L; Keirnan, Jacqueline M; Worth, Anna C; Hodges, Sally E; Leen, Ann M; Fisher, William E; Vera, Juan F

    2011-01-01

    Objective Conventional chemotherapy and radiotherapy produce marginal survival benefits in pancreatic cancer, underscoring the need for novel therapies. The aim of this study is to develop an adoptive T cell transfer approach to target tumours expressing prostate stem cell antigen (PSCA), a tumour-associated antigen that is frequently expressed by pancreatic cancer cells. Methods Expression of PSCA on cell lines and primary tumour samples was confirmed by immunohistochemistry. Healthy donor- and patient-derived T cells were isolated, activated in vitro using CD3/CD28, and transduced with a retroviral vector encoding a chimeric antigen receptor (CAR) targeting PSCA. The ability of these cells to kill tumour cells was analysed by chromium-51 (Cr51) release. Results Prostate stem cell antigen was expressed on >70% of the primary tumour samples screened. Activated, CAR-modified T cells could be readily generated in clinically relevant numbers and were specifically able to kill PSCA-expressing pancreatic cancer cell lines with no non-specific killing of PSCA-negative target cells, thus indicating the potential efficacy and safety of this approach. Conclusions Prostate stem cell antigen is frequently expressed on pancreatic cancer cells and can be targeted for immune-mediated destruction using CAR-modified, adoptively transferred T cells. The safety and efficacy of this approach indicate that it deserves further study and may represent a promising novel treatment for patients with pancreatic cancer. PMID:21843265

  4. Clonal analysis of the T-cell response to in vivo expressed Mycobacterium tuberculosis protein Rv2034, using a CD154 expression based T-cell cloning method.

    Directory of Open Access Journals (Sweden)

    Susanna Commandeur

    Full Text Available Tuberculosis (TB, caused by Mycobacterium tuberculosis (Mtb, remains a leading cause of death worldwide. A better understanding of the role of CD4+ and CD8+ T cells, which are both important to TB protection, is essential to unravel the mechanisms of protection and to identify the key antigens seen by these T cells. We have recently identified a set of in vivo expressed Mtb genes (IVE-TB which is expressed during in vivo pulmonary infection in mice, and shown that their encoded antigens are potently recognized by polyclonal T cells from tuberculin skin test-positive, in vitro ESAT-6/CFP10-responsive individuals. Here we have cloned T cells specific for one of these newly identified in vivo expressed Mtb (IVE-TB antigens, Rv2034. T cells were enriched based on the expression of CD154 (CD40L, which represents a new method for selecting antigen-specific (low frequency T cells independent of their specific function. An Rv2034-specific CD4+ T-cell clone expressed the Th1 markers T-bet, IFN-γ, TNF-α, IL-2 and the cytotoxicity related markers granzyme B and CD107a as measured by flow cytometry. The clone specifically recognized Rv2034 protein, Rv2034 peptide p81-100 and Mtb lysate. Remarkably, while the recognition of the dominant p81-100 epitope was HLA-DR restricted, the T-cell clone also recognized a neighboring epitope (p88-107 in an HLA-DR- as well as HLA-DQ1-restricted fashion. Importantly, the T-cell clone was able to inhibit Mtb outgrowth from infected monocytes significantly. The characterization of the polyfunctional and Mtb inhibitory T-cell response to IVE-TB Rv2034 at the clonal level provides detailed further insights into the potential of IVE-TB antigens as new vaccine candidate antigens in TB. Our new approach allowed the identification of T-cell subsets that likely play a significant role in controlling Mtb infection, and can be applied to the analysis of T-cell responses in patient populations.

  5. Infliximab induces clonal expansion of γδ-T cells in Crohn's disease: a predictor of lymphoma risk?

    Directory of Open Access Journals (Sweden)

    Jens Kelsen

    Full Text Available BACKGROUND: Concominant with the widespread use of combined immunotherapy in the management of Crohn's disease (CD, the incidence of hepato-splenic gamma-delta (γδ-T cell lymphoma has increased sharply in CD patients. Malignant transformation of lymphocytes is believed to be a multistep process resulting in the selection of malignant γδ-T cell clones. We hypothesised that repeated infusion of anti-TNF-α agents may induce clonal selection and that concurrent treatment with immunomodulators further predisposes patients to γδ-T cell expansion. METHODOLOGY/PRINCIPAL FINDINGS: We investigated dynamic changes in the γδ-T cells of patient with CD following treatment with infliximab (Remicade®; n=20 or adalimumab (Humira®; n=26 using flow cytometry. In patients with a high γδ-T cell level, the γδ-T cells were assessed for clonality. Of these 46 CD patients, 35 had a γδ-T cells level (mean 1.6% comparable to healthy individuals (mean 2.2%, and 11 CD patients (24% exhibited an increased level of γδ-T cells (5-15%. In the 18 patients also receiving thiopurines or methotrexate, the average baseline γδ-T cell level was 4.4%. In three male CD patients with a high baseline value, the γδ-T cell population increased dramatically following infliximab therapy. A fourth male patient also on infliximab monotherapy presented with 20% γδ-T cells, which increased to 25% shortly after treatment and was 36% between infusions. Clonality studies revealed an oligoclonal γδ-T cell pattern with dominant γδ-T cell clones. In support of our clinical findings, in vitro experiments showed a dose-dependent proliferative effect of anti-TNF-α agents on γδ-T cells. CONCLUSION/SIGNIFICANCE: CD patients treated with immunomodulators had constitutively high levels of γδ-T cells. Infliximab exacerbated clonal γδ-T cell expansion in vivo and induced γδ-T cell proliferation in vitro. Overall, young, male CD patients with high baseline γδ-T cell

  6. Infliximab induces clonal expansion of γδ-T cells in Crohn's disease: a predictor of lymphoma risk?

    Science.gov (United States)

    Kelsen, Jens; Dige, Anders; Schwindt, Heinrich; D'Amore, Francesco; Pedersen, Finn S; Agnholt, Jørgen; Christensen, Lisbet A; Dahlerup, Jens F; Hvas, Christian L

    2011-03-31

    Concominant with the widespread use of combined immunotherapy in the management of Crohn's disease (CD), the incidence of hepato-splenic gamma-delta (γδ)-T cell lymphoma has increased sharply in CD patients. Malignant transformation of lymphocytes is believed to be a multistep process resulting in the selection of malignant γδ-T cell clones. We hypothesised that repeated infusion of anti-TNF-α agents may induce clonal selection and that concurrent treatment with immunomodulators further predisposes patients to γδ-T cell expansion. We investigated dynamic changes in the γδ-T cells of patient with CD following treatment with infliximab (Remicade®; n=20) or adalimumab (Humira®; n=26) using flow cytometry. In patients with a high γδ-T cell level, the γδ-T cells were assessed for clonality. Of these 46 CD patients, 35 had a γδ-T cells level (mean 1.6%) comparable to healthy individuals (mean 2.2%), and 11 CD patients (24%) exhibited an increased level of γδ-T cells (5-15%). In the 18 patients also receiving thiopurines or methotrexate, the average baseline γδ-T cell level was 4.4%. In three male CD patients with a high baseline value, the γδ-T cell population increased dramatically following infliximab therapy. A fourth male patient also on infliximab monotherapy presented with 20% γδ-T cells, which increased to 25% shortly after treatment and was 36% between infusions. Clonality studies revealed an oligoclonal γδ-T cell pattern with dominant γδ-T cell clones. In support of our clinical findings, in vitro experiments showed a dose-dependent proliferative effect of anti-TNF-α agents on γδ-T cells. CD patients treated with immunomodulators had constitutively high levels of γδ-T cells. Infliximab exacerbated clonal γδ-T cell expansion in vivo and induced γδ-T cell proliferation in vitro. Overall, young, male CD patients with high baseline γδ-T cell levels may be at an increased risk of developing malignant γδ-T cell lymphomas

  7. CD4+CD62L+ Central Memory T Cells Can Be Converted to Foxp3+ T Cells

    Science.gov (United States)

    Zhang, Xiaolong; Chang Li, Xian; Xiao, Xiang; Sun, Rui; Tian, Zhigang; Wei, Haiming

    2013-01-01

    The peripheral Foxp3+ Treg pool consists of naturally arising Treg (nTreg) and adaptive Treg cells (iTreg). It is well known that naive CD4+ T cells can be readily converted to Foxp3+ iTreg in vitro, and memory CD4+ T cells are resistant to conversion. In this study, we investigated the induction of Foxp3+ T cells from various CD4+ T-cell subsets in human peripheral blood. Though naive CD4+ T cells were readily converted to Foxp3+ T cells with TGF-β and IL-2 treatment in vitro, such Foxp3+ T cells did not express the memory marker CD45RO as do Foxp3+ T cells induced in the peripheral blood of Hepatitis B Virus (HBV) patients. Interestingly, a subset of human memory CD4+ T cells, defined as CD62L+ central memory T cells, could be induced by TGF-β to differentiate into Foxp3+ T cells. It is well known that Foxp3+ T cells derived from human CD4+CD25- T cells in vitro are lack suppressive functions. Our data about the suppressive functions of CD4+CD62L+ central memory T cell-derived Foxp3+ T cells support this conception, and an epigenetic analysis of these cells showed a similar methylation pattern in the FOXP3 Treg-specific demethylated region as the naive CD4+ T cell-derived Foxp3+ T cells. But further research showed that mouse CD4+ central memory T cells also could be induced to differentiate into Foxp3+ T cells, such Foxp3+ T cells could suppress the proliferation of effector T cells. Thus, our study identified CD4+CD62L+ central memory T cells as a novel potential source of iTreg. PMID:24155942

  8. Neuron-mediated generation of regulatory T cells from encephalitogenic T cells suppresses EAE

    DEFF Research Database (Denmark)

    Liu, Yawei; Teige, Ingrid; Birnir, Bryndis

    2006-01-01

    Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS) inflamma......Neurons have been neglected as cells with a major immune-regulatory function because they do not express major histocompatibility complex class II. Our data show that neurons are highly immune regulatory, having a crucial role in governing T-cell response and central nervous system (CNS......) inflammation. Neurons induce the proliferation of activated CD4+ T cells through B7-CD28 and transforming growth factor (TGF)-beta1-TGF-beta receptor signaling pathways, resulting in amplification of T-cell receptor signaling through phosphorylated ZAP-70, interleukin (IL)-2 and IL-9. The interaction between...... neurons and T cells results in the conversion of encephalitogenic T cells to CD25+ TGF-beta1+ CTLA-4+ FoxP3+ T regulatory (Treg) cells that suppress encephalitogenic T cells and inhibit experimental autoimmune encephalomyelitis. Suppression is dependent on cytotoxic T lymphocyte antigen (CTLA)-4...

  9. 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...... 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...... peptide in the Elispot culture. Immunization with a mixture of the VSV-peptide and a "normal" peptide also resulted in IFNγ spot formation without addition of peptide to the assay culture. Peptide-tetramer staining of CD8(+) T cells from mice immunized with a mixture of VSV-peptide and "normal" peptide...

  10. MHC class II molecules regulate growth in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Odum, Niels; Bendtzen, K

    1994-01-01

    MHC-class-II-positive T cells are found in tissues involved in autoimmune disorders. Stimulation of class II molecules by monoclonal antibodies (mAbs) or bacterial superantigens induces protein tyrosine phosphorylation through activation of protein tyrosine kinases in T cells, and class II signals...... lines tested. Only one of three CD4+, CD45RAhigh, ROhigh T cells responded to class II costimulation. There was no correlation between T cell responsiveness to class II and the cytokine production profile of the T cell in question. Thus, T cell lines producing interferon (IFN)-gamma but not IL-4 (TH1...... modulate several T cell responses. Here, we studied further the role of class II molecules in the regulation of T cell growth. Costimulation of class II molecules by immobilized HLA-DR mAb significantly enhanced interleukin (IL)-2-supported T cell growth of the majority of CD4+, CD45RAlow, ROhigh T cell...

  11. Hili Inhibits HIV Replication in Activated T Cells.

    Science.gov (United States)

    Peterlin, B Matija; Liu, Pingyang; Wang, Xiaoyun; Cary, Daniele; Shao, Wei; Leoz, Marie; Hong, Tian; Pan, Tao; Fujinaga, Koh

    2017-06-01

    P-element-induced wimpy-like (Piwil) proteins restrict the replication of mobile genetic elements in the germ line. They are also expressed in many transformed cell lines. In this study, we discovered that the human Piwil 2 (Hili) protein can also inhibit HIV replication, especially in activated CD4 + T cells that are the preferred target cells for this virus in the infected host. Although resting cells did not express Hili, its expression was rapidly induced following T cell activation. In these cells and transformed cell lines, depletion of Hili increased levels of viral proteins and new viral particles. Further studies revealed that Hili binds to tRNA. Some of the tRNAs represent rare tRNA species, whose codons are overrepresented in the viral genome. Targeting tRNA Arg (UCU) with an antisense oligonucleotide replicated effects of Hili and also inhibited HIV replication. Finally, Hili also inhibited the retrotransposition of the endogenous intracysternal A particle (IAP) by a similar mechanism. Thus, Hili joins a list of host proteins that inhibit the replication of HIV and other mobile genetic elements. IMPORTANCE Piwil proteins inhibit the movement of mobile genetic elements in the germ line. In their absence, sperm does not form and male mice are sterile. This inhibition is thought to occur via small Piwi-interacting RNAs (piRNAs). However, in some species and in human somatic cells, Piwil proteins bind primarily to tRNA. In this report, we demonstrate that human Piwil proteins, especially Hili, not only bind to select tRNA species, including rare tRNAs, but also inhibit HIV replication. Importantly, T cell activation induces the expression of Hili in CD4 + T cells. Since Hili also inhibited the movement of an endogenous retrovirus (IAP), our finding shed new light on this intracellular resistance to exogenous and endogenous retroviruses as well as other mobile genetic elements. Copyright © 2017 American Society for Microbiology.

  12. T-cells fighting B-cell lymphoproliferative malignancies: the emerging field of CD19 CAR T-cell therapy

    NARCIS (Netherlands)

    Heijink, D. M.; Kater, A. P.; Hazenberg, M. D.; Hagenbeek, A.; Kersten, M. J.

    2016-01-01

    CAR T-cells are autologous T-cells transduced with a chimeric antigen receptor (CAR). The CAR contains an antigen recognition part (originating from an antibody), a T-cell receptor transmembrane and cytoplasmic signalling part, and one or more co-stimulatory domains. While CAR T-cells can be

  13. Ability of γδ T cells to modulate the Foxp3 T cell response is dependent on adenosine.

    Directory of Open Access Journals (Sweden)

    Dongchun Liang

    Full Text Available Whether γδ T cells inhibit or enhance the Foxp3 T cell response depends upon their activation status. The critical enhancing effector in the supernatant is adenosine. Activated γδ T cells express adenosine receptors at high levels, which enables them to deprive Foxp3+ T cells of adenosine, and to inhibit their expansion. Meanwhile, cell-free supernatants of γδ T cell cultures enhance Foxp3 T cell expansion. Thus, inhibition and enhancement by γδ T cells of Foxp3 T cell response are a reflection of the balance between adenosine production and absorption by γδ T cells. Non-activated γδ T cells produce adenosine but bind little, and thus enhance the Foxp3 T cell response. Activated γδ T cells express high density of adenosine receptors and have a greatly increased ability to bind adenosine. Extracellular adenosine metabolism and expression of adenosine receptor A2ARs by γδ T cells played a major role in the outcome of γδ and Foxp3 T cell interactions. A better understanding of the functional conversion of γδ T cells could lead to γδ T cell-targeted immunotherapies for related diseases.

  14. Termination of T cell priming relies on a phase of unresponsiveness promoting disengagement from APCs and T cell division.

    Science.gov (United States)

    Bohineust, Armelle; Garcia, Zacarias; Beuneu, Hélène; Lemaître, Fabrice; Bousso, Philippe

    2018-05-07

    T cells are primed in secondary lymphoid organs by establishing stable interactions with antigen-presenting cells (APCs). However, the cellular mechanisms underlying the termination of T cell priming and the initiation of clonal expansion remain largely unknown. Using intravital imaging, we observed that T cells typically divide without being associated to APCs. Supporting these findings, we demonstrate that recently activated T cells have an intrinsic defect in establishing stable contacts with APCs, a feature that was reflected by a blunted capacity to stop upon T cell receptor (TCR) engagement. T cell unresponsiveness was caused, in part, by a general block in extracellular calcium entry. Forcing TCR signals in activated T cells antagonized cell division, suggesting that T cell hyporesponsiveness acts as a safeguard mechanism against signals detrimental to mitosis. We propose that transient unresponsiveness represents an essential phase of T cell priming that promotes T cell disengagement from APCs and favors effective clonal expansion. © 2018 Bohineust et al.

  15. Narcolepsy Type 1 Is Associated with a Systemic Increase and Activation of Regulatory T Cells and with a Systemic Activation of Global T Cells.

    Directory of Open Access Journals (Sweden)

    Michel Lecendreux

    Full Text Available Narcolepsy is a rare neurologic disorder characterized by excessive daytime sleepiness, cataplexy and disturbed nocturnal sleep patterns. Narcolepsy type 1 (NT1 has been shown to result from a selective loss of hypothalamic hypocretin-secreting neurons with patients typically showing low CSF-hypocretin levels (<110 pg/ml. This specific loss of hypocretin and the strong association with the HLA-DQB1*06:02 allele led to the hypothesis that NT1 could be an immune-mediated pathology. Moreover, susceptibility to NT1 has recently been associated with several pathogens, particularly with influenza A H1N1 virus either through infection or vaccination. The goal of this study was to compare peripheral blood immune cell populations in recent onset pediatric NT1 subjects (post or non-post 2009-influenza A H1N1 vaccination to healthy donors. We demonstrated an increased number of central memory CD4+ T cells (CD62L+ CD45RA- associated to an activated phenotype (increase in CD69 and CD25 expression in NT1 patients. Percentage and absolute count of regulatory T cells (Tregs in NT1 patients were increased associated with an activated phenotype (increase in GITR and LAP expression, and of activated memory phenotype. Cytokine production by CD4+ and CD8+ T cells after activation was not modified in NT1 patients. In H1N1 vaccinated NT1 patients, absolute counts of CD3+, CD8+ T cells, and B cells were increased compared to non-vaccinated NT1 patients. These results support a global T cell activation in NT1 patients and thus support a T cell-mediated autoimmune origin of NT1, but do not demonstrate the pathological role of H1N1 prophylactic vaccination. They should prompt further studies of T cells, particularly of Tregs (such as suppression and proliferation antigen specific assays, and also T-cell receptor sequencing, in NT1.

  16. Narcolepsy Type 1 Is Associated with a Systemic Increase and Activation of Regulatory T Cells and with a Systemic Activation of Global T Cells.

    Science.gov (United States)

    Lecendreux, Michel; Churlaud, Guillaume; Pitoiset, Fabien; Regnault, Armelle; Tran, Tu Anh; Liblau, Roland; Klatzmann, David; Rosenzwajg, Michelle

    2017-01-01

    Narcolepsy is a rare neurologic disorder characterized by excessive daytime sleepiness, cataplexy and disturbed nocturnal sleep patterns. Narcolepsy type 1 (NT1) has been shown to result from a selective loss of hypothalamic hypocretin-secreting neurons with patients typically showing low CSF-hypocretin levels (NT1 could be an immune-mediated pathology. Moreover, susceptibility to NT1 has recently been associated with several pathogens, particularly with influenza A H1N1 virus either through infection or vaccination. The goal of this study was to compare peripheral blood immune cell populations in recent onset pediatric NT1 subjects (post or non-post 2009-influenza A H1N1 vaccination) to healthy donors. We demonstrated an increased number of central memory CD4+ T cells (CD62L+ CD45RA-) associated to an activated phenotype (increase in CD69 and CD25 expression) in NT1 patients. Percentage and absolute count of regulatory T cells (Tregs) in NT1 patients were increased associated with an activated phenotype (increase in GITR and LAP expression), and of activated memory phenotype. Cytokine production by CD4+ and CD8+ T cells after activation was not modified in NT1 patients. In H1N1 vaccinated NT1 patients, absolute counts of CD3+, CD8+ T cells, and B cells were increased compared to non-vaccinated NT1 patients. These results support a global T cell activation in NT1 patients and thus support a T cell-mediated autoimmune origin of NT1, but do not demonstrate the pathological role of H1N1 prophylactic vaccination. They should prompt further studies of T cells, particularly of Tregs (such as suppression and proliferation antigen specific assays, and also T-cell receptor sequencing), in NT1.

  17. Role of the T cell receptor ligand affinity in T cell activation by bacterial superantigens

    DEFF Research Database (Denmark)

    Andersen, P S; Geisler, C; Buus, S

    2001-01-01

    Similar to native peptide/MHC ligands, bacterial superantigens have been found to bind with low affinity to the T cell receptor (TCR). It has been hypothesized that low ligand affinity is required to allow optimal TCR signaling. To test this, we generated variants of Staphylococcus enterotoxin C3...... (SEC3) with up to a 150-fold increase in TCR affinity. By stimulating T cells with SEC3 molecules immobilized onto plastic surfaces, we demonstrate that increasing the affinity of the SEC3/TCR interaction caused a proportional increase in the ability of SEC3 to activate T cells. Thus, the potency...... correlation between ligand affinity and ligand potency indicating that it is the density of receptor-ligand complexes in the T cell contact area that determines TCR signaling strength....

  18. Evidence of endothelial inflammation, T cell activation, and T cell reallocation in uncomplicated Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Elhassan, I M; Hviid, L; Satti, G

    1994-01-01

    endothelium. We measured plasma levels of soluble markers of endothelial inflammation and T cell activation in 32 patients suffering from acute, uncomplication P. falciparum malaria, as well as in 10 healthy, aparasitemic control donors. All donors were residents of a malaria-endemic area of Eastern State...... Sudan. In addition, we measured the T cell surface expression of the interleukin-2 receptor (CD25) and the lymphocyte function-associated antigen (LFA-1; CD11a/CD18). We found that the plasma levels of all inflammation and activation markers were significantly increased in the malaria patients compared...... with the control donors. In addition, we found a disease-induced depletion of T cells with high expression of the LFA-1 antigen, particularly in the CD4+ subset. The results obtained provide further support for the hypothesis of T cell reallocation to inflamed endothelium in acute P. falciparum malaria....

  19. Ageing combines CD4 T cell lymphopenia in secondary lymphoid organs and T cell accumulation in gut associated lymphoid tissue

    OpenAIRE

    Martinet , Kim ,; Bloquet , Stéphane; Bourgeois , Christine

    2014-01-01

    International audience; BackgroundCD4 T cell lymphopenia is an important T cell defect associated to ageing. Higher susceptibility to infections, cancer, or autoimmune pathologies described in aged individuals is thought to partly rely on T cell lymphopenia. We hypothesize that such diverse effects may reflect anatomical heterogeneity of age related T cell lymphopenia. Indeed, no data are currently available on the impact of ageing on T cell pool recovered from gut associated lymphoid tissue ...

  20. T-cell response in human leishmaniasis

    DEFF Research Database (Denmark)

    Kharazmi, A; Kemp, K; Ismail, A

    1999-01-01

    In the present communication we provide evidence for the existence of a Th1/Th2 dichotomy in the T-cell response to Leishmania antigens in human leishmaniasis. Our data suggest that the pattern of IL-4 and IFN-gamma response is polarised in these patients. Lymphocytes from individuals recovered...... from cutaneous leishmaniasis (CL) responded by IFN-gamma production following stimulation with Leishmania antigens whereas cells from patients recovered from visceral leishmaniasis (VL) showed a mixed pattern of IFN-gamma and IL-4 responses. The cells producing these cytokines were predominantly CD4......+. Furthermore, IL-10 plays an important role in the development of post kala azar dermal leishmaniasis (PKDL) from VL. The balance between the parasitic-specific T-cell response plays an important regulatory role in determining the outcome of Leishmania infections in humans....

  1. Presentation of lipid antigens to T cells.

    Science.gov (United States)

    Mori, Lucia; De Libero, Gennaro

    2008-04-15

    T cells specific for lipid antigens participate in regulation of the immune response during infections, tumor immunosurveillance, allergy and autoimmune diseases. T cells recognize lipid antigens as complexes formed with CD1 antigen-presenting molecules, thus resembling recognition of MHC-peptide complexes. The biophysical properties of lipids impose unique mechanisms for their delivery, internalization into antigen-presenting cells, membrane trafficking, processing, and loading of CD1 molecules. Each of these steps is controlled at molecular and celular levels and determines lipid immunogenicity. Lipid antigens may derive from microbes and from the cellular metabolism, thus allowing the immune system to survey a large repertoire of immunogenic molecules. Recognition of lipid antigens facilitates the detection of infectious agents and the initiation of responses involved in immunoregulation and autoimmunity. This review focuses on the presentation mechanisms and specific recognition of self and bacterial lipid antigens and discusses the important open issues.

  2. Accumulation of cytolytic CD8{sup +} T cells in B16-melanoma and proliferation of mature T cells in TIS21-knockout mice after T cell receptor stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Min Sook [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Woo, Min-Yeong [Department of Microbiology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Department of Biomedical Sciences, The Graduate School, Ajou University (Korea, Republic of); Kwon, Daeho [Department of Microbiology, Kwandong University College of Medicine, Gangneung, Gangwon-do 210-701 (Korea, Republic of); Hong, Allen E. [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Song, Kye Yong [Department of Pathology, Chung-Ang University College of Medicine, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Park, Sun [Department of Microbiology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of); Lim, In Kyoung [Department of Biochemistry and Molecular Biology, Ajou University School of Medicine, 164, World cul-ro, Yeongtong-gu, Suwon, Gyeonggi-do 443-380 (Korea, Republic of)

    2014-10-01

    In vivo and in vitro effects of TIS21 gene on the mature T cell activation and antitumor activities were explored by employing MO5 melanoma orthograft and splenocytes isolated from the TIS21-knockout (KO) mice. Proliferation and survival of mature T cells were significantly increased in the KO than the wild type (WT) cells, indicating that TIS21 inhibits the rate of mature T cell proliferation and its survival. In MO5 melanoma orthograft model, the KO mice recruited much more CD8{sup +} T cells into the tumors at around day 14 after tumor cell injection along with reduced tumor volumes compared with the WT. The increased frequency of granzyme B{sup +} CD8{sup +} T cells in splenocytes of the KO mice compared with the WT may account for antitumor-immunity of TIS21 gene in the melanoma orthograft. In contrast, reduced frequencies of CD107a{sup +} CD8{sup +} T cells in the splenocytes of KO mice may affect the loss of CD8{sup +} T cell infiltration in the orthograft at around day 19. These results indicate that TIS21 exhibits antiproliferative and proapoptotic effects in mature T cells, and differentially affects the frequencies of granzyme B{sup +} CD8{sup +} T-cells and CD107a{sup +} CD8{sup +} T-cells, thus transiently regulating in vivo anti-tumor immunity. - Highlights: • Constitutive expression of TIS21 in splenocytes and upregulation by TCR stimulation. • Proliferation of mature T-cells in spleen of TIS21KO mice after TCR stimulation. • Inhibition of cell death in mature T-cells of TIS21KO mice compared with the wild type. • Inhibition of melanoma growth in TIS21KO mice and CD8{sup +} T cell infiltration in tumor. • Reduction of CD 107{sup +}CD8{sup +} T cells, but increased granzyme B{sup +} CD8{sup +} T cells in TIS21KO mice.

  3. Perspectives on Regulatory T Cell Therapies

    OpenAIRE

    Probst-Kepper, Michael; Kröger, Andrea; Garritsen, Henk S.P.; Buer, Jan

    2009-01-01

    Adoptive transfer in animal models clearly indicate an essential role of CD4+ CD25+ FOXP3+ regulatory T (Treg) cells in prevention and treatment of autoimmune and graft-versus-host disease. Thus, Treg cell therapies and development of drugs that specifically enhance Treg cell function and development represent promising tools to establish dominant tolerance. So far, lack of specific markers to differentiate human Treg cells from activated CD4+ CD25+ effector T cells, which also express FOXP3 ...

  4. Regulatory T cells: immune suppression and beyond

    OpenAIRE

    Wan, Yisong Y

    2010-01-01

    Foxp3-expressing regulatory T cells (Tregs) were originally identified as critical in maintaining self-tolerance and immune homeostasis. The immunosuppressive functions of Tregs are widely acknowledged and have been extensively studied. Recent studies have revealed many diverse roles of Tregs in shaping the immune system and the inflammatory response. This review will discuss our efforts as well as the efforts of others towards understanding the multifaceted function of Treg...

  5. Improve T Cell Therapy in Neuroblastoma

    Science.gov (United States)

    2014-07-01

    relapsed lymphoma following genetic modi - fi cation of tumor-antigen presenting cells and T-lymphocyte transfer. Blood 110:2838–2845 4. Heslop HE et...CD4þCD25þFOXP3þ regulatory T cells of both healthy subjects and type 1 diabetic patients. J Immunol 2006;177:8338–47. 32. HeslopHE, SlobodKS,PuleMA

  6. Improve T Cell Therapy in Neuroblastoma

    Science.gov (United States)

    2015-09-01

    bioluminescence was then measured overtime. The graph is representative of one of 4 experiments using CMV-CTLs from 4 donors. Panel E. Kaplan-Meier...whole-cell vaccine expressing the iC9 gene and labeled with an enhanced firefly luciferase. Tumor growth was measured by in vivo imaging. Panel E...down regulation in LTE -T cells is not caused by specific culture conditions. T lymphocytes were activated with immobilized OKT3 (1 μg ml) and

  7. Human T Cell Memory: A Dynamic View

    Directory of Open Access Journals (Sweden)

    Derek C. Macallan

    2017-02-01

    Full Text Available Long-term T cell-mediated protection depends upon the formation of a pool of memory cells to protect against future pathogen challenge. In this review we argue that looking at T cell memory from a dynamic viewpoint can help in understanding how memory populations are maintained following pathogen exposure or vaccination. For example, a dynamic view resolves the apparent paradox between the relatively short lifespans of individual memory cells and very long-lived immunological memory by focussing on the persistence of clonal populations, rather than individual cells. Clonal survival is achieved by balancing proliferation, death and differentiation rates within and between identifiable phenotypic pools; such pools correspond broadly to sequential stages in the linear differentiation pathway. Each pool has its own characteristic kinetics, but only when considered as a population; single cells exhibit considerable heterogeneity. In humans, we tend to concentrate on circulating cells, but memory T cells in non-lymphoid tissues and bone marrow are increasingly recognised as critical for immune defence; their kinetics, however, remain largely unexplored. Considering vaccination from this viewpoint shifts the focus from the size of the primary response to the survival of the clone and enables identification of critical system pinch-points and opportunities to improve vaccine efficacy.

  8. CD4+ T-Cell Reactivity to Orexin/Hypocretin in Patients With Narcolepsy Type 1.

    Science.gov (United States)

    Ramberger, Melanie; Högl, Birgit; Stefani, Ambra; Mitterling, Thomas; Reindl, Markus; Lutterotti, Andreas

    2017-03-01

    Narcolepsy type 1 is accompanied by a selective loss of orexin/hypocretin (hcrt) neurons in the lateral hypothalamus caused by yet unknown mechanisms. Epidemiologic and genetic associations strongly suggest an immune-mediated pathogenesis of the disease. We compared specific T-cell reactivity to orexin/hcrt peptides in peripheral blood mononuclear cells of narcolepsy type 1 patients to healthy controls by a carboxyfluorescein succinimidyl ester proliferation assay. Orexin/hcrt-specific T-cell reactivity was also determined by cytokine (interferon gamma and granulocyte-macrophage colony-stimulating factor) analysis. Individuals were considered as responders if the cell division index of CD3+CD4+ T cells and both stimulation indices of cytokine secretion exceeded the cutoff 3. Additionally, T-cell reactivity to orexin/hcrt had to be confirmed by showing reactivity to single peptides present in different peptide pools. Using these criteria, 3/15 patients (20%) and 0/13 controls (0%) showed orexin/hcrt-specific CD4+ T-cell proliferation (p = .2262). The heterogeneous reactivity pattern did not allow the identification of a preferential target epitope. A significant role of orexin/hcrt-specific T cells in narcolepsy type 1 patients could not be confirmed in this study. Further studies are needed to assess the exact role of CD4+ T cells and possible target antigens in narcolepsy type 1 patients. © Sleep Research Society 2016. Published by Oxford University Press [on behalf of the Sleep Research Society].

  9. Oestrogen, an evolutionary conserved regulator of T cell differentiation and immune tolerance in jawed vertebrates?

    Science.gov (United States)

    Paiola, Matthieu; Knigge, Thomas; Duflot, Aurélie; Pinto, Patricia I S; Farcy, Emilie; Monsinjon, Tiphaine

    2018-07-01

    In teleosts, as in mammals, the immune system is tightly regulated by sexual steroid hormones, such as oestrogens. We investigated the effects of 17β-oestradiol on the expression of several genes related to T cell development and resulting T cell subpopulations in sea bass, Dicentrarchus labrax, for a primary lymphoid organ, the thymus, and two secondary lymphoid organs, the head-kidney and the spleen. In parallel, the oxidative burst capacity was assessed in leucocytes of the secondary lymphoid organs. Apoptosis- and proliferation-related genes, indicative of B and T cell clonal selection and lymphoid progenitor activity, were not affected by elevated oestrogen-levels. Sex-related oestrogen-responsiveness in T cell and antigen-presenting cell markers was observed, the expression of which was differentially induced by oestrogen-exposure in the three lymphoid organs. Remarkably, in the spleen, oestrogen increased regulatory T cell-related gene expression was associated with a decrease in oxidative burst capacity. To the best of our knowledge, this study indicates for the first time that physiological levels of oestrogen are likely to promote immune tolerance by modulating thymic function (i.e., T cell development and output) and peripheral T cells in teleosts, similar to previously reported oestrogenic effects in mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Performance-enhancing drugs: design and production of redirected chimeric antigen receptor (CAR) T cells.

    Science.gov (United States)

    Levine, B L

    2015-03-01

    Performance enhancement of the immune system can now be generated through ex vivo gene modification of T cells in order to redirect native specificity to target tumor antigens. This approach combines the specificity of antibody therapy, the expanded response of cellular therapy and the memory activity of vaccine therapy. Recent clinical trials of chimeric antigen receptor (CAR) T cells directed toward CD19 as a stand-alone therapy have shown sustained complete responses in patients with acute lymphoblastic leukemia and chronic lymphocytic leukemia. As these drug products are individually derived from a patient's own cells, a different manufacturing approach is required for this kind of personalized therapy compared with conventional drugs. Key steps in the CAR T-cell manufacturing process include the selection and activation of isolated T cells, transduction of T cells to express CARs, ex vivo expansion of modified T cells and cryopreservation in infusible media. In this review, the steps involved in isolating, genetically modifying and scaling-out the CAR T cells for use in a clinical setting are described in the context of in-process and release testing and regulatory standards.

  11. Clinical trials of CAR-T cells in China

    Directory of Open Access Journals (Sweden)

    Bingshan Liu

    2017-10-01

    Full Text Available Abstract Novel immunotherapeutic agents targeting tumor-site microenvironment are revolutionizing cancer therapy. Chimeric antigen receptor (CAR-engineered T cells are widely studied for cancer immunotherapy. CD19-specific CAR-T cells, tisagenlecleucel, have been recently approved for clinical application. Ongoing clinical trials are testing CAR designs directed at novel targets involved in hematological and solid malignancies. In addition to trials of single-target CAR-T cells, simultaneous and sequential CAR-T cells are being studied for clinical applications. Multi-target CAR-engineered T cells are also entering clinical trials. T cell receptor-engineered CAR-T and universal CAR-T cells represent new frontiers in CAR-T cell development. In this study, we analyzed the characteristics of CAR constructs and registered clinical trials of CAR-T cells in China and provided a quick glimpse of the landscape of CAR-T studies in China.

  12. Clinical trials of CAR-T cells in China.

    Science.gov (United States)

    Liu, Bingshan; Song, Yongping; Liu, Delong

    2017-10-23

    Novel immunotherapeutic agents targeting tumor-site microenvironment are revolutionizing cancer therapy. Chimeric antigen receptor (CAR)-engineered T cells are widely studied for cancer immunotherapy. CD19-specific CAR-T cells, tisagenlecleucel, have been recently approved for clinical application. Ongoing clinical trials are testing CAR designs directed at novel targets involved in hematological and solid malignancies. In addition to trials of single-target CAR-T cells, simultaneous and sequential CAR-T cells are being studied for clinical applications. Multi-target CAR-engineered T cells are also entering clinical trials. T cell receptor-engineered CAR-T and universal CAR-T cells represent new frontiers in CAR-T cell development. In this study, we analyzed the characteristics of CAR constructs and registered clinical trials of CAR-T cells in China and provided a quick glimpse of the landscape of CAR-T studies in China.

  13. Langerin+ dermal dendritic cells are critical for CD8+ T cell activation and IgH γ-1 class switching in response to gene gun vaccines.

    Science.gov (United States)

    Stoecklinger, Angelika; Eticha, Tekalign D; Mesdaghi, Mehrnaz; Kissenpfennig, Adrien; Malissen, Bernard; Thalhamer, Josef; Hammerl, Peter

    2011-02-01

    The C-type lectin langerin/CD207 was originally discovered as a specific marker for epidermal Langerhans cells (LC). Recently, additional and distinct subsets of langerin(+) dendritic cells (DC) have been identified in lymph nodes and peripheral tissues of mice. Although the role of LC for immune activation or modulation is now being discussed controversially, other langerin(+) DC appear crucial for protective immunity in a growing set of infection and vaccination models. In knock-in mice that express the human diphtheria toxin receptor under control of the langerin promoter, injection of diphtheria toxin ablates LC for several weeks whereas other langerin(+) DC subsets are replenished within just a few days. Thus, by careful timing of diphtheria toxin injections selective states of deficiency in either LC only or all langerin(+) cells can be established. Taking advantage of this system, we found that, unlike selective LC deficiency, ablation of all langerin(+) DC abrogated the activation of IFN-γ-producing and cytolytic CD8(+) T cells after gene gun vaccination. Moreover, we identified migratory langerin(+) dermal DC as the subset that directly activated CD8(+) T cells in lymph nodes. Langerin(+) DC were also critical for IgG1 but not IgG2a Ab induction, suggesting differential polarization of CD4(+) T helper cells by langerin(+) or langerin-negative DC, respectively. In contrast, protein vaccines administered with various adjuvants induced IgG1 independently of langerin(+) DC. Taken together, these findings reflect a highly specialized division of labor between different DC subsets both with respect to Ag encounter as well as downstream processes of immune activation.

  14. Retinoic acid signalling in thymocytes regulates T cell development

    DEFF Research Database (Denmark)

    Wendland, Kerstin; Sitnik, Katarzyna Maria; Kotarsky, Knut

    . Here, using a RA sensitive reporter mouse model, we demonstrate that endogenous RAR responses are induced in CD69+CD4+CD8lo and CD69+CD4+CD8+ thymocytes undergoing positive selection and lineage commitment, and continue to be present in both CD4+ and CD8+ single positive (SP) cells, with RA signaling...... further enhanced in recently generated CD69+ CD4+ SP cells. To address the potential biological significance of RA signaling in developing thymocytes, we evaluated T cell development in CD4Cre-dnRAR mice, where RA signaling is blocked in thymocytes from the CD4+CD8+ double positive (DP) stage onwards due...

  15. Power Laser Ablation Symposia

    CERN Document Server

    Phipps, Claude

    2007-01-01

    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  16. A group-specific inhibitor of lysosomal cysteine proteinases selectively inhibits both proteolytic degradation and presentation of the antigen dinitrophenyl-poly-L-lysine by guinea pig accessory cells to T cells

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1986-01-01

    of antigens by guinea pig accessory cells. The proteinase inhibitor benzyloxycarbonyl-phenylalanylalanine-diazomethyl-ketone, which selectively inhibits cysteine proteinases, was used to block this set of enzymes in cultured cells. We demonstrate that the selective inhibition of the cysteine proteinases...

  17. Surfactant protein D delays Fas- and TRAIL-mediated extrinsic pathway of apoptosis in T cells.

    Science.gov (United States)

    Djiadeu, Pascal; Kotra, Lakshmi P; Sweezey, Neil; Palaniyar, Nades

    2017-05-01

    Only a few extracellular soluble proteins are known to modulate apoptosis. We considered that surfactant-associated protein D (SP-D), an innate immune collectin present on many mucosal surfaces, could regulate apoptosis. Although SP-D is known to be important for immune cell homeostasis, whether SP-D affects apoptosis is unknown. In this study we aimed to determine the effects of SP-D on Jurkat T cells and human T cells dying by apoptosis. Here we show that SP-D binds to Jurkat T cells and delays the progression of Fas (CD95)-Fas ligand and TRAIL-TRAIL receptor induced, but not TNF-TNF receptor-mediated apoptosis. SP-D exerts its effects by reducing the activation of initiator caspase-8 and executioner caspase-3. SP-D also delays the surface exposure of phosphatidylserine. The effect of SP-D was ablated by the presence of caspase-8 inhibitor, but not by intrinsic pathway inhibitors. The binding ability of SP-D to dying cells decreases during the early stages of apoptosis, suggesting the release of apoptotic cell surface targets during apoptosis. SP-D also delays FasL-induced death of primary human T cells. SP-D delaying the progression of the extrinsic pathway of apoptosis could have important implications in regulating immune cell homeostasis at mucosal surfaces.

  18. Loss of receptor on tuberculin-reactive T-cells marks active pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Mathias Streitz

    Full Text Available BACKGROUND: Tuberculin-specific T-cell responses have low diagnostic specificity in BCG vaccinated populations. While subunit-antigen (e.g. ESAT-6, CFP-10 based tests are useful for diagnosing latent tuberculosis infection, there is no reliable immunological test for active pulmonary tuberculosis. Notably, all existing immunological tuberculosis-tests are based on T-cell response size, whereas the diagnostic potential of T-cell response quality has never been explored. This includes surface marker expression and functionality of mycobacterial antigen specific T-cells. METHODOLOGY/PRINCIPAL FINDINGS: Flow-cytometry was used to examine over-night antigen-stimulated T-cells from tuberculosis patients and controls. Tuberculin and/or the relatively M. tuberculosis specific ESAT-6 protein were used as stimulants. A set of classic surface markers of T-cell naïve/memory differentiation was selected and IFN-gamma production was used to identify T-cells recognizing these antigens. The percentage of tuberculin-specific T-helper-cells lacking the surface receptor CD27, a state associated with advanced differentiation, varied considerably between individuals (from less than 5% to more than 95%. Healthy BCG vaccinated individuals had significantly fewer CD27-negative tuberculin-reactive CD4 T-cells than patients with smear and/or culture positive pulmonary tuberculosis, discriminating these groups with high sensitivity and specificity, whereas individuals with latent tuberculosis infection exhibited levels in between. CONCLUSIONS/SIGNIFICANCE: Smear and/or culture positive pulmonary tuberculosis can be diagnosed by a rapid and reliable immunological test based on the distribution of CD27 expression on peripheral blood tuberculin specific T-cells. This test works very well even in a BCG vaccinated population. It is simple and will be of great utility in situations where sputum specimens are difficult to obtain or sputum-smear is negative. It will also help

  19. Milk-induced eczema is associated with the expansion of T cells expressing cutaneous lymphocyte antigen.

    Science.gov (United States)

    Abernathy-Carver, K J; Sampson, H A; Picker, L J; Leung, D Y

    1995-02-01

    The extravasation of T cells at sites of inflammation is critically dependent on the activity of homing receptors (HR) involved in endothelial cell recognition and binding. Two such HR (the cutaneous lymphocyte antigen [CLA] and L-selectin) have been shown to be selectively involved in T cell migration to skin and peripheral lymph nodes, respectively. This study was designed to assess the relationship between the organ specificity of an allergic reaction to food and the expression of HR on T cells activated in vitro by the relevant food allergen. Peripheral blood mononuclear cells were isolated from seven milk allergic children with a history of eczema when exposed to milk. All patients had a positive prick skin test and double-blind placebo-controlled food challenge to milk. 10 children with either allergic eosinophilic gastroenteritis or milk-induced enterocolitis and 8 nonatopic adults served as controls. Five-parameter flow cytometry using monoclonal antibodies was used for detection of the specific HR on freshly isolated T cells versus T cell blasts induced by a 6-d incubation with casein, as compared with Candida albicans. After in vitro stimulation with casein, but not C. albicans, patients with milk allergy and atopic dermatitis had a significantly greater percentage of CLA+ T cells (P < 0.01) than controls with milk-induced enterocolitis, allergic eosinophilic gastroenteritis, or nonatopic healthy controls. In contrast, the percentage of L-selectin-expressing T cells did not differ significantly between these groups. These data suggest that after casein stimulation allergic patients with milk-induced skin disease have an expanded population of CLA+ T cells, as compared with nonatopics or allergic patients without skin involvement. We postulate that heterogeneity in the regulation of HR expression on antigen-specific T cells may play a role in determining sites of involvement in tissue-directed allergic responses.

  20. Conventional CD4+ T cells present bacterial antigens to induce cytotoxic and memory CD8+ T cell responses.

    Science.gov (United States)

    Cruz-Adalia, Aránzazu; Ramirez-Santiago, Guillermo; Osuna-Pérez, Jesús; Torres-Torresano, Mónica; Zorita, Virgina; Martínez-Riaño, Ana; Boccasavia, Viola; Borroto, Aldo; Martínez Del Hoyo, Gloria; González-Granado, José María; Alarcón, Balbino; Sánchez-Madrid, Francisco; Veiga, Esteban

    2017-11-17

    Bacterial phagocytosis and antigen cross-presentation to activate CD8 + T cells are principal functions of professional antigen presenting cells. However, conventional CD4 + T cells also capture and kill bacteria from infected dendritic cells in a process termed transphagocytosis (also known as transinfection). Here, we show that transphagocytic T cells present bacterial antigens to naive CD8 + T cells, which proliferate and become cytotoxic in response. CD4 + T-cell-mediated antigen presentation also occurs in vivo in the course of infection, and induces the generation of central memory CD8 + T cells with low PD-1 expression. Moreover, transphagocytic CD4 + T cells induce protective anti-tumour immune responses by priming CD8 + T cells, highlighting the potential of CD4 + T cells as a tool for cancer immunotherapy.

  1. Radiofrequency ablation of pulmonary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Crocetti, Laura, E-mail: l.crocetti@med.unipi.i [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy); Lencioni, Riccardo [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy)

    2010-07-15

    The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

  2. Function of the Nucleotide Exchange Activity of Vav1 in T cell Development and Activation*

    Science.gov (United States)

    Saveliev, Alexander; Vanes, Lesley; Ksionda, Olga; Rapley, Jonathan; Smerdon, Stephen J.; Rittinger, Katrin; Tybulewicz, Victor L. J.

    2012-01-01

    The guanine nucleotide exchange factor (GEF) Vav1 is essential for transducing T cell antigen receptor (TCR) signals and therefore plays a critical role in the development and activation of T cells. It has been presumed that the GEF activity of Vav1 is important for its function; however, there has been no direct demonstration of this. Here, we generated mice expressing enzymatically inactive, but normally folded, Vav1 protein. Analysis of these mice showed that the GEF activity of Vav1 was necessary for the selection of thymocytes and for the optimal activation of T cells, including signal transduction to Rac1, Akt, and integrins. In contrast, the GEF activity of Vav1 was not required for TCR-induced calcium flux, activation of extracellular signal–regulated kinase (ERK) and protein kinase D1 (PKD1), and cell polarization. Thus, in T cells, the GEF activity of Vav1 is essential for some, but not all, of its functions. PMID:20009105

  3. Function of the nucleotide exchange activity of vav1 in T cell development and activation.

    Science.gov (United States)

    Saveliev, Alexander; Vanes, Lesley; Ksionda, Olga; Rapley, Jonathan; Smerdon, Stephen J; Rittinger, Katrin; Tybulewicz, Victor L J

    2009-12-15

    The guanine nucleotide exchange factor (GEF) Vav1 is essential for transducing T cell antigen receptor (TCR) signals and therefore plays a critical role in the development and activation of T cells. It has been presumed that the GEF activity of Vav1 is important for its function; however, there has been no direct demonstration of this. Here, we generated mice expressing enzymatically inactive, but normally folded, Vav1 protein. Analysis of these mice showed that the GEF activity of Vav1 was necessary for the selection of thymocytes and for the optimal activation of T cells, including signal transduction to Rac1, Akt, and integrins. In contrast, the GEF activity of Vav1 was not required for TCR-induced calcium flux, activation of extracellular signal-regulated kinase and protein kinase D1, and cell polarization. Thus, in T cells, the GEF activity of Vav1 is essential for some, but not all, of its functions.

  4. Human Epidermal Langerhans Cells Maintain Immune Homeostasis in Skin by Activating Skin Resident Regulatory T Cells

    Science.gov (United States)

    Seneschal, Julien; Clark, Rachael A.; Gehad, Ahmed; Baecher-Allan, Clare M.; Kupper, Thomas S.

    2013-01-01

    Recent discoveries indicate that the skin of a normal individual contains 10-20 billion resident memory T cells ( which include various T helper, T cytotoxic, and T regulatory subsets, that are poised to respond to environmental antigens. Using only autologous human tissues, we report that both in vitro and in vivo, resting epidermal Langerhan cells (LC) selectively and specifically induced the activation and proliferation of skin resident regulatory T cells (Treg), a minor subset of skin resident memory T cells. In the presence of foreign pathogen, however, the same LC activated and induced proliferation of effector memory T (Tem) cells and limited Treg cells activation. These underappreciated properties of LC: namely maintenance of tolerance in normal skin, and activation of protective skin resident memory T cells upon infectious challenge, help clarify the role of LC in skin. PMID:22560445

  5. Phosphoinositide 3–kinase γ participates in T cell receptor–induced T cell activation

    Science.gov (United States)

    Alcázar, Isabela; Marqués, Miriam; Kumar, Amit; Hirsch, Emilio; Wymann, Matthias; Carrera, Ana C.; Barber, Domingo F.

    2007-01-01

    Class I phosphoinositide 3–kinases (PI3Ks) constitute a family of enzymes that generates 3-phosphorylated polyphosphoinositides at the cell membrane after stimulation of protein tyrosine (Tyr) kinase–associated receptors or G protein–coupled receptors (GPCRs). The class I PI3Ks are divided into two types: class IA p85/p110 heterodimers, which are activated by Tyr kinases, and the class IB p110γ isoform, which is activated by GPCR. Although the T cell receptor (TCR) is a protein Tyr kinase–associated receptor, p110γ deletion affects TCR-induced T cell stimulation. We examined whether the TCR activates p110γ, as well as the consequences of interfering with p110γ expression or function for T cell activation. We found that after TCR ligation, p110γ interacts with Gαq/11, lymphocyte-specific Tyr kinase, and ζ-associated protein. TCR stimulation activates p110γ, which affects 3-phosphorylated polyphosphoinositide levels at the immunological synapse. We show that TCR-stimulated p110γ controls RAS-related C3 botulinum substrate 1 activity, F-actin polarization, and the interaction between T cells and antigen-presenting cells, illustrating a crucial role for p110γ in TCR-induced T cell activation. PMID:17998387

  6. T-cell regulation in lepromatous leprosy.

    Directory of Open Access Journals (Sweden)

    Kidist Bobosha

    2014-04-01

    Full Text Available Regulatory T (Treg cells are known for their role in maintaining self-tolerance and balancing immune reactions in autoimmune diseases and chronic infections. However, regulatory mechanisms can also lead to prolonged survival of pathogens in chronic infections like leprosy and tuberculosis (TB. Despite high humoral responses against Mycobacterium leprae (M. leprae, lepromatous leprosy (LL patients have the characteristic inability to generate T helper 1 (Th1 responses against the bacterium. In this study, we investigated the unresponsiveness to M. leprae in peripheral blood mononuclear cells (PBMC of LL patients by analysis of IFN-γ responses to M. leprae before and after depletion of CD25+ cells, by cell subsets analysis of PBMC and by immunohistochemistry of patients' skin lesions. Depletion of CD25+ cells from total PBMC identified two groups of LL patients: 7/18 (38.8% gained in vitro responsiveness towards M. leprae after depletion of CD25+ cells, which was reversed to M. leprae-specific T-cell unresponsiveness by addition of autologous CD25+ cells. In contrast, 11/18 (61.1% remained anergic in the absence of CD25+ T-cells. For both groups mitogen-induced IFN-γ was, however, not affected by depletion of CD25+ cells. In M. leprae responding healthy controls, treated lepromatous leprosy (LL and borderline tuberculoid leprosy (BT patients, depletion of CD25+ cells only slightly increased the IFN-γ response. Furthermore, cell subset analysis showed significantly higher (p = 0.02 numbers of FoxP3+ CD8+CD25+ T-cells in LL compared to BT patients, whereas confocal microscopy of skin biopsies revealed increased numbers of CD68+CD163+ as well as FoxP3+ cells in lesions of LL compared to tuberculoid and borderline tuberculoid leprosy (TT/BT lesions. Thus, these data show that CD25+ Treg cells play a role in M. leprae-Th1 unresponsiveness in LL.

  7. Genomewide analyses of pathogenic and regulatory T cells of NOD ...

    Indian Academy of Sciences (India)

    DANG SUN

    Two regulatory T cell clones (Tregs) were used in this study. Treg1 cells were clone-derived from the previously described. Keywords. methylation; cDNA microarray; type 1 diabetes; pathogenic T cells; .... Gender-specific differences in.

  8. Natural Killer T Cells in Cancer Immunotherapy

    Science.gov (United States)

    Nair, Shiny; Dhodapkar, Madhav V.

    2017-01-01

    Natural killer T (NKT) cells are specialized CD1d-restricted T cells that recognize lipid antigens. Following stimulation, NKT cells lead to downstream activation of both innate and adaptive immune cells in the tumor microenvironment. This has impelled the development of NKT cell-targeted immunotherapies for treating cancer. In this review, we provide a brief overview of the stimulatory and regulatory functions of NKT cells in tumor immunity as well as highlight preclinical and clinical studies based on NKT cells. Finally, we discuss future perspectives to better harness the potential of NKT cells for cancer therapy. PMID:29018445

  9. Improve T Cell Therapy in Neuroblastoma

    Science.gov (United States)

    2012-07-01

    Savoldo B, Vigouroux S et al. T lymphocytes redirected against the kappa light chain of human immunoglobulin efficiently kill mature B lymphocyte...Natl Acad Sci U S A. 2004;101(suppl 2):14622–14626. 8. Eghtesad S, Morel PA, Clemens PR. The companions : regulatory T cells and gene therapy...were euthanized and examined for NKT cell localiza- tion to the tumor tissues. Animals treated with anti-CCL2 or anti- CCL20 mAb had lower frequency

  10. Downregulation of IL-17-producing T cells is associated with regulatory T cell expansion and disease progression in chronic lymphocytic leukemia.

    Science.gov (United States)

    Jadidi-Niaragh, Farhad; Ghalamfarsa, Ghasem; Memarian, Ali; Asgarian-Omran, Hossein; Razavi, Seyed Mohsen; Sarrafnejad, Abdolfattah; Shokri, Fazel

    2013-04-01

    Little is known about the immunobiology of interleukin-17 (IL-17)-producing T cells and regulatory T cells (Treg) in chronic lymphocytic leukemia (CLL). In this study, the frequencies of Th17, Tc17, and CD39(+) Treg cells were enumerated in peripheral T cells isolated from 40 CLL patients and 15 normal subjects by flow cytometry. Our results showed a lower frequency of Th17 and Tc17 cells in progressive (0.99 ± 0.12 % of total CD3(+)CD4(+) cells; 0.44 ± 0.09 % of total CD8(+) cells) compared to indolent patients (1.57 ± 0.24 %, p = 0.042; 0.82 ± 0.2 %, p = 0.09) and normal subjects (1.78 ± 0.2 %, p = 0.003; 0.71 ± 0.09 %, p = 0.04). Decrease in IL-17-producing T cells was associated with CD39(+) Treg cells expansion. Variation of IL-17-producing cells and Treg cells in indolent and progressive patients was neither associated to the expression levels of Th1- and Th2-specific transcription factors T-bet and GATA-3 nor to the frequencies of IFN-γ and IL-4-producing CD4(+) T cells in a selected number of samples. Additionally, suppressive potential of CD4(+) Treg was similar in CLL patients and normal subjects. Our data indicate that progression of CLL is associated with downregulation of IL-17-producing T cells and expansion of Treg cells, implying contribution of these subsets of T cells in the progression of CLL.

  11. γ/δ T cell subsets in human aging using the classical α/β T cell model.

    Science.gov (United States)

    Vasudev, Anusha; Ying, Crystal Tan Tze; Ayyadhury, Shamini; Puan, Kia Joo; Andiappan, Anand Kumar; Nyunt, Ma Shwe Zin; Shadan, Nurhidaya Binte; Mustafa, Seri; Low, Ivy; Rotzschke, Olaf; Fulop, Tamas; Ng, Tze Pin; Larbi, Anis

    2014-10-01

    Aging is associated with an increased susceptibility to infections and diseases. It has also been associated with reduced functionality and altered distribution of immune cells, especially T cells. Whereas classical α/β T cells, especially CD8(+) T cells, were shown to be highly susceptible to aging, the effects of viral persistent stimulations on the fate of γ/δ T cells are much less documented. Healthy, elderly individuals of Chinese ethnical background were recruited under the aegis of SLAS-II. In this observational study, γ/δ T cell populations were characterized by flow cytometry and compared with the α/β CD4(+) and CD8(+) T cells in elderly and young controls. In our study, we identified a reduced frequency of γ/δ T cells but not α/β T cells with aging. The classical markers of α/β T cell aging, including CD28, CD27, and CD57, did not prove significant for γ/δ T cells. The extreme range of expression of these markers in γ/δ T cells was responsible for the lack of relationship between γ/δ T cell subsets, CD4/CD8 ratio, and anti-CMV titers that was significant for α/β T cells and, especially, CD8(+) T cells. Although markers of aging for γ/δ T cells are not clearly identified, our data collectively suggest that the presence of CD27 γ/δ T cells is associated with markers of α/β T cell aging. © 2014 Society for Leukocyte Biology.

  12. Apoptosis and T cell depletion during feline infectious peritonitis

    OpenAIRE

    Horzinek, M.C.; Haagmans, B.L.; Egberink, H.F.

    1996-01-01

    Cats that have succumbed to feline infectious peritonitis, an immune- mediated disease caused by variants of feline coronaviruses, show apoptosis and T-cell depletion in their lymphoid organs. The ascitic fluid that develops in the course of the condition causes apoptosis in vitro but only in activated T cells. Since feline infectious peritonitis virus does not infect T cells, and viral proteins did not inhibit T-cell proliferation, we postulate that soluble mediators released during the infe...

  13. Auto-reactive T cells revised. Overestimation based on methodology?

    DEFF Research Database (Denmark)

    Thorlacius-Ussing, Gorm; Sørensen, Jesper F; Wandall, Hans H

    2015-01-01

    . Thus, T cell antigen reactivities identified with unmodified antigens in vitro may in part represent in vitro T cell activation against neo-epitopes and not true in vivo autoreactivity as postulated. This methodological problem may have implications for the interpretation of the frequent reporting...... methodology applied to document T cell reactivity against unmodified protein or peptide may lead to overinterpretation of the reported frequencies of autoreactive CD4+ and CD8+ T cells....

  14. A novel xenograft model of cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Krejsgaard, Thorbjørn; Kopp, Katharina; Ralfkiaer, Elisabeth

    2010-01-01

    Cutaneous T-cell lymphomas (CTCLs) are characterized by accumulation of malignant T cells in the skin. Early disease resembles benign skin disorders but during disease progression cutaneous tumors develop, and eventually the malignant T cells can spread to lymph nodes and internal organs. However...... and lymphatic tumors, originated from the transplanted malignant T cells. In conclusion, we describe a novel mouse model of tumor stage CTCL for future studies of disease dissemination and preclinical evaluations of new therapeutic strategies....

  15. Differential responses of human regulatory T cells (Treg and effector T cells to rapamycin.

    Directory of Open Access Journals (Sweden)

    Laura Strauss

    Full Text Available BACKGROUND: The immunosuppressive drug rapamycin (RAPA promotes the expansion of CD4(+ CD25(highFoxp3(+ regulatory T cells via mechanisms that remain unknown. Here, we studied expansion, IL-2R-gamma chain signaling, survival pathways and resistance to apoptosis in human Treg responding to RAPA. METHODOLOGY/PRINCIPAL FINDINGS: CD4(+CD25(+ and CD4(+CD25(neg T cells were isolated from PBMC of normal controls (n = 21 using AutoMACS. These T cell subsets were cultured in the presence of anti-CD3/CD28 antibodies and 1000 IU/mL IL-2 for 3 to 6 weeks. RAPA (1-100 nM was added to half of the cultures. After harvest, the cell phenotype, signaling via the PI3K/mTOR and STAT pathways, expression of survival proteins and Annexin V binding were determined and compared to values obtained with freshly-separated CD4(+CD25(high and CD4(+CD25(neg T cells. Suppressor function was tested in co-cultures with autologous CFSE-labeled CD4(+CD25(neg or CD8(+CD25(neg T-cell responders. The frequency and suppressor activity of Treg were increased after culture of CD4(+CD25(+ T cells in the presence of 1-100 nM RAPA (p<0.001. RAPA-expanded Treg were largely CD4(+CD25(highFoxp3(+ cells and were resistant to apoptosis, while CD4(+CD25(neg T cells were sensitive. Only Treg upregulated anti-apoptotic and down-regulated pro-apoptotic proteins. Treg expressed higher levels of the PTEN protein than CD4(+CD25(neg cells. Activated Treg+/-RAPA preferentially phosphorylated STAT5 and STAT3 and did not utilize the PI3K/mTOR pathway. CONCLUSIONS/SIGNIFICANCE: RAPA favors Treg expansion and survival by differentially regulating signaling, proliferation and sensitivity to apoptosis of human effector T cells and Treg after TCR/IL-2 activation.

  16. Perspectives on Regulatory T Cell Therapies.

    Science.gov (United States)

    Probst-Kepper, Michael; Kröger, Andrea; Garritsen, Henk S P; Buer, Jan

    2009-01-01

    Adoptive transfer in animal models clearly indicate an essential role of CD4+ CD25+ FOXP3+ regulatory T (T(reg)) cells in prevention and treatment of autoimmune and graft-versus-host disease. Thus, T(reg) cell therapies and development of drugs that specifically enhance T(reg) cell function and development represent promising tools to establish dominant tolerance. So far, lack of specific markers to differentiate human T(reg) cells from activated CD4+ CD25+ effector T cells, which also express FOXP3 at different levels, hampered such an approach. Recent identification of the orphan receptor glycoprotein-A repetitions predominant (GARP or LRRC32) as T(reg) cell-specific key molecule that dominantly controls FOXP3 via a positive feedback loop opens up new perspectives for molecular and cellular therapies. This brief review focuses on the role of GARP as a safeguard of a complex regulatory network of human T(reg) cells and its implications for regulatory T cell therapies in autoimmunity and graft-versus-host disease.

  17. Unraveling Natural Killer T-Cells Development

    Directory of Open Access Journals (Sweden)

    Sabrina Bianca Bennstein

    2018-01-01

    Full Text Available Natural killer T-cells are a subset of innate-like T-cells with the ability to bridge innate and adaptive immunity. There is great interest in harnessing these cells to improve tumor therapy; however, greater understanding of invariant NKT (iNKT cell biology is needed. The first step is to learn more about NKT development within the thymus. Recent studies suggest lineage separation of murine iNKT cells into iNKT1, iNKT2, and iNKT17 cells instead of shared developmental stages. This review will focus on these new studies and will discuss the evidence for lineage separation in contrast to shared developmental stages. The author will also highlight the classifications of murine iNKT cells according to identified transcription factors and cytokine production, and will discuss transcriptional and posttranscriptional regulations, and the role of mammalian target of rapamycin. Finally, the importance of these findings for human cancer therapy will be briefly discussed.

  18. Two separate defects affecting true naive or virtual memory T cell precursors combine to reduce naive T cell responses with aging.

    Science.gov (United States)

    Renkema, Kristin R; Li, Gang; Wu, Angela; Smithey, Megan J; Nikolich-Žugich, Janko

    2014-01-01

    Naive T cell responses are eroded with aging. We and others have recently shown that unimmunized old mice lose ≥ 70% of Ag-specific CD8 T cell precursors and that many of the remaining precursors acquire a virtual (central) memory (VM; CD44(hi)CD62L(hi)) phenotype. In this study, we demonstrate that unimmunized TCR transgenic (TCRTg) mice also undergo massive VM conversion with age, exhibiting rapid effector function upon both TCR and cytokine triggering. Age-related VM conversion in TCRTg mice directly depended on replacement of the original TCRTg specificity by endogenous TCRα rearrangements, indicating that TCR signals must be critical in VM conversion. Importantly, we found that VM conversion had adverse functional effects in both old wild-type and old TCRTg mice; that is, old VM, but not old true naive, T cells exhibited blunted TCR-mediated, but not IL-15-mediated, proliferation. This selective proliferative senescence correlated with increased apoptosis in old VM cells in response to peptide, but decreased apoptosis in response to homeostatic cytokines IL-7 and IL-15. Our results identify TCR as the key factor in differential maintenance and function of Ag-specific precursors in unimmunized mice with aging, and they demonstrate that two separate age-related defects--drastic reduction in true naive T cell precursors and impaired proliferative capacity of their VM cousins--combine to reduce naive T cell responses with aging.

  19. Ptpn11 Deletion in CD4+ Cells Does Not Affect T Cell Development and Functions but Causes Cartilage Tumors in a T Cell-Independent Manner.

    Science.gov (United States)

    Miah, S M Shahjahan; Jayasuriya, Chathuraka T; Salter, Alexander I; Reilly, Emma C; Fugere, Céline; Yang, Wentian; Chen, Qian; Brossay, Laurent

    2017-01-01

    The ubiquitously expressed tyrosine phosphatase Src homology region 2 domain-containing phosphatase-2 (SHP-2, encoded by Ptpn11 ) is required for constitutive cellular processes including proliferation, differentiation, and the regulation of immune responses. During development and maturation, subsets of T cells express a variety of inhibitory receptors known to associate with phosphatases, which in turn, dephosphorylate key players of activating receptor signaling pathways. We hypothesized that SHP-2 deletion would have major effects on T cell development by altering the thresholds for activation, as well as positive and negative selection. Surprisingly, using mice conditionally deficient for SHP-2 in the T cell lineage, we show that the development of these lymphocytes is globally intact. In addition, our data demonstrate that SHP-2 absence does not compromise T cell effector functions, suggesting that SHP-2 is dispensable in these cells. Unexpectedly, in aging mice, Ptpn11 gene deletion driven by CD4 Cre recombinase leads to cartilage tumors in wrist bones in a T cell-independent manner. These tumors resemble miniature cartilaginous growth plates and contain CD4-lineage positive chondrocyte-like cells. Altogether these results indicate that SHP-2 is a cartilage tumor suppressor during aging.

  20. Ptpn11 Deletion in CD4+ Cells Does Not Affect T Cell Development and Functions but Causes Cartilage Tumors in a T Cell-Independent Manner

    Directory of Open Access Journals (Sweden)

    S. M. Shahjahan Miah

    2017-10-01

    Full Text Available The ubiquitously expressed tyrosine phosphatase Src homology region 2 domain-containing phosphatase-2 (SHP-2, encoded by Ptpn11 is required for constitutive cellular processes including proliferation, differentiation, and the regulation of immune responses. During development and maturation, subsets of T cells express a variety of inhibitory receptors known to associate with phosphatases, which in turn, dephosphorylate key players of activating receptor signaling pathways. We hypothesized that SHP-2 deletion would have major effects on T cell development by altering the thresholds for activation, as well as positive and negative selection. Surprisingly, using mice conditionally deficient for SHP-2 in the T cell lineage, we show that the development of these lymphocytes is globally intact. In addition, our data demonstrate that SHP-2 absence does not compromise T cell effector functions, suggesting that SHP-2 is dispensable in these cells. Unexpectedly, in aging mice, Ptpn11 gene deletion driven by CD4 Cre recombinase leads to cartilage tumors in wrist bones in a T cell-independent manner. These tumors resemble miniature cartilaginous growth plates and contain CD4-lineage positive chondrocyte-like cells. Altogether these results indicate that SHP-2 is a cartilage tumor suppressor during aging.

  1. A retinoic acid-dependent checkpoint in the development of CD4+ T cell-mediated immunity.

    Science.gov (United States)

    Pino-Lagos, Karina; Guo, Yanxia; Brown, Chrysothemis; Alexander, Matthew P; Elgueta, Raúl; Bennett, Kathryn A; De Vries, Victor; Nowak, Elizabeth; Blomhoff, Rune; Sockanathan, Shanthini; Chandraratna, Roshantha A; Dmitrovsky, Ethan; Noelle, Randolph J

    2011-08-29

    It is known that vitamin A and its metabolite, retinoic acid (RA), are essential for host defense. However, the mechanisms for how RA controls inflammation are incompletely understood. The findings presented in this study show that RA signaling occurs concurrent with the development of inflammation. In models of vaccination and allogeneic graft rejection, whole body imaging reveals that RA signaling is temporally and spatially restricted to the site of inflammation. Conditional ablation of RA signaling in T cells significantly interferes with CD4(+) T cell effector function, migration, and polarity. These findings provide a new perspective of the role of RA as a mediator directly controlling CD4(+) T cell differentiation and immunity. © 2011 Pino-Lagos et al.

  2. T-cell epitopes from viral and tumor associated antigens: induction and analysis of antigen-specific T cells

    OpenAIRE

    Nastke, Maria-Dorothea

    2005-01-01

    T cells are important effectors in the defense of human pathogens entering the organism. CD8+ T cells recognize peptides which are presented by MHC class I molecules and lyse cells which are infected by virus or intracellular pathogens. Moreover, they are able to destroy cancer cells. CD4+ T cells recognize peptides from exogenous proteins acquired by endocytosis or from internalized plasma membrane proteins which are presented on MHC class II. CD4+ T cells play an important role in the defen...

  3. Natural killer cells promote early CD8 T cell responses against cytomegalovirus.

    Directory of Open Access Journals (Sweden)

    Scott H Robbins

    2007-08-01

    Full Text Available Understanding the mechanisms that help promote protective immune responses to pathogens is a major challenge in biomedical research and an important goal for the design of innovative therapeutic or vaccination strategies. While natural killer (NK cells can directly contribute to the control of viral replication, whether, and how, they may help orchestrate global antiviral defense is largely unknown. To address this question, we took advantage of the well-defined molecular interactions involved in the recognition of mouse cytomegalovirus (MCMV by NK cells. By using congenic or mutant mice and wild-type versus genetically engineered viruses, we examined the consequences on antiviral CD8 T cell responses of specific defects in the ability of the NK cells to control MCMV. This system allowed us to demonstrate, to our knowledge for the first time, that NK cells accelerate CD8 T cell responses against a viral infection in vivo. Moreover, we identify the underlying mechanism as the ability of NK cells to limit IFN-alpha/beta production to levels not immunosuppressive to the host. This is achieved through the early control of cytomegalovirus, which dramatically reduces the activation of plasmacytoid dendritic cells (pDCs for cytokine production, preserves the conventional dendritic cell (cDC compartment, and accelerates antiviral CD8 T cell responses. Conversely, exogenous IFN-alpha administration in resistant animals ablates cDCs and delays CD8 T cell activation in the face of NK cell control of viral replication. Collectively, our data demonstrate that the ability of NK cells to respond very early to cytomegalovirus infection critically contributes to balance the intensity of other innate immune responses, which dampens early immunopathology and promotes optimal initiation of antiviral CD8 T cell responses. Thus, the extent to which NK cell responses benefit the host goes beyond their direct antiviral effects and extends to the prevention of innate

  4. Tissue-specific control of latent CMV reactivation by regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Maha Almanan

    2017-08-01

    Full Text Available Cytomegalovirus (CMV causes a persistent, lifelong infection. CMV persists in a latent state and undergoes intermittent subclinical viral reactivation that is quelled by ongoing T cell responses. While T cells are critical to maintain control of infection, the immunological factors that promote CMV persistence remain unclear. Here, we investigated the role of regulatory T cells (Treg in a mouse model of latent CMV infection using Foxp3-diphtheria toxin receptor (Foxp3-DTR mice. Eight months after infection, MCMV had established latency in the spleen, salivary gland, lung, and pancreas, which was accompanied by an increased frequency of Treg. Administration of diphtheria toxin (DT after establishment of latency efficiently depleted Treg and drove a significant increase in the numbers of functional MCMV-specific CD4+ and CD8+ T cells. Strikingly, Treg depletion decreased the number of animals with reactivatable latent MCMV in the spleen. Unexpectedly, in the same animals, ablation of Treg drove a significant increase in viral reactivation in the salivary gland that was accompanied with augmented local IL-10 production by Foxp3-CD4+T cells. Further, neutralization of IL-10 after Treg depletion significantly decreased viral load in the salivary gland. Combined, these data show that Treg have divergent control of MCMV infection depending upon the tissue. In the spleen, Treg antagonize CD8+ effector function and promote viral persistence while in the salivary gland Treg prevent IL-10 production and limit viral reactivation and replication. These data provide new insights into the organ-specific roles of Treg in controlling the reactivation of latent MCMV infection.

  5. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    International Nuclear Information System (INIS)

    Doi, Keiko; Fujimoto, Takahiro; Okamura, Tadashi; Ogawa, Masahiro; Tanaka, Yoko; Mototani, Yasumasa; Goto, Motohito; Ota, Takeharu; Matsuzaki, Hiroshi; Kuroki, Masahide; Tsunoda, Toshiyuki; Sasazuki, Takehiko; Shirasawa, Senji

    2012-01-01

    Highlights: ► We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. ► Zfat-deficiency leads to reduction in the number of the peripheral T cells. ► Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. ► Decreased expression of IL-7Rα, IL-2Rα and IL-2 in Zfat-deficient peripheral T cells. ► Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7Rα and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2Rα expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  6. Clinical significance of T-cell clonality in mycosis fungoides and other cutaneous T-cell lymphomas

    NARCIS (Netherlands)

    Muche, Joachim Marcus

    2010-01-01

    The purpose of this thesis was to obtain more insight into T-cell clonality in blood of mycosis fungoides (MF) patients. Investigation of the frequency of blood T-cell clonality clearly indicated early dissemination of neoplastic T-cells into skin and blood as a sign of physiological recirculation.

  7. Overexpression of IL-7R alpha provides a competitive advantage during early T-cell development.

    Science.gov (United States)

    Laouar, Yasmina; Crispe, I Nicholas; Flavell, Richard A

    2004-03-15

    Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre-T-cell antigen receptor. Although alpha beta T-cell development is observed in IL-7- and IL-7R alpha-deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7R alpha that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7R alpha was revealed by surface staining, and increased IL-7R alpha mRNA was documented by using reverse transcriptase-polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL(+) (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]-fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.

  8. Specifically activated memory T cell subsets from cancer patients recognize and reject xenotransplanted autologous tumors

    Science.gov (United States)

    Beckhove, Philipp; Feuerer, Markus; Dolenc, Mathias; Schuetz, Florian; Choi, Carmen; Sommerfeldt, Nora; Schwendemann, Jochen; Ehlert, Katrin; Altevogt, Peter; Bastert, Gunther; Schirrmacher, Volker; Umansky, Viktor

    2004-01-01

    Bone marrow of breast cancer patients was found to contain CD8+ T cells specific for peptides derived from breast cancer–associated proteins MUC1 and Her-2/neu. Most of these cells had a central or effector memory phenotype (CD45RA–CD62L+ or CD45RA–CD62L–, respectively). To test their in vivo function, we separated bone marrow–derived CD45RA+ naive or CD45RA–CD45RO+ memory T cells, stimulated them with autologous dendritic cells pulsed with tumor lysate, and transferred them into NOD/SCID mice bearing autologous breast tumors and normal skin transplants. CD45RA– memory but not CD45RA+ naive T cells infiltrated autologous tumor but not skin tissues after the transfer. These tumor-infiltrating cells had a central or effector memory phenotype and produced perforin. Many of them expressed the P-selectin glycoprotein ligand 1 and were found around P-selectin+ tumor endothelium. Tumor infiltration included cluster formation in tumor tissue by memory T cells with cotransferred dendritic cells. It was associated with the induction of tumor cell apoptosis and significant tumor reduction. We thus demonstrate selective homing of memory T cells to human tumors and suggest that tumor rejection is based on the recognition of tumor-associated antigens on tumor cells and dendritic cells by autologous specifically activated central and effector memory T cells. PMID:15232613

  9. CAR-T cell therapy in gastrointestinal tumors and hepatic carcinoma: From bench to bedside.

    Science.gov (United States)

    Zhang, Qi; Zhang, Zimu; Peng, Meiyu; Fu, Shuyu; Xue, Zhenyi; Zhang, Rongxin

    2016-01-01

    The chimeric antigen receptor (CAR) is a genetically engineered receptor that combines a scFv domain, which specifically recognizes the tumor-specific antigen, with T cell activation domains. CAR-T cell therapies have demonstrated tremendous efficacy against hematologic malignancies in many clinical trials. Recent studies have extended these efforts to the treatment of solid tumors. However, the outcomes of CAR-T cell therapy for solid tumors are not as remarkable as the outcomes have been for hematologic malignancies. A series of hurdles has arisen with respect to CAR-T cell-based immunotherapy, which needs to be overcome to target solid tumors. The major challenge for CAR-T cell therapy in solid tumors is the selection of the appropriate specific antigen to demarcate the tumor from normal tissue. In this review, we discuss the application of CAR-T cells to gastrointestinal and hepatic carcinomas in preclinical and clinical research. Furthermore, we analyze the usefulness of several specific markers in the study of gastrointestinal tumors and hepatic carcinoma.

  10. Primed T cell responses to chemokines are regulated by the immunoglobulin-like molecule CD31.

    Directory of Open Access Journals (Sweden)

    Madhav Kishore

    Full Text Available CD31, an immunoglobulin-like molecule expressed by leukocytes and endothelial cells, is thought to contribute to the physiological regulation T cell homeostasis due to the presence of two immunotyrosine-based inhibitory motifs in its cytoplasmic tail. Indeed, loss of CD31 expression leads to uncontrolled T cell-mediated inflammation in a variety of experimental models of disease and certain CD31 polymorphisms correlate with increased disease severity in human graft-versus-host disease and atherosclerosis. The molecular mechanisms underlying CD31-mediated regulation of T cell responses have not yet been clarified. We here show that CD31-mediated signals attenuate T cell chemokinesis both in vitro and in vivo. This effect selectively affects activated/memory T lymphocytes, in which CD31 is clustered on the cell membrane where it segregates to the leading edge. We provide evidence that this molecular segregation, which does not occur in naïve T lymphocytes, might lead to cis-CD31 engagement on the same membrane and subsequent interference with the chemokine-induced PI3K/Akt signalling pathway. We propose that CD31-mediated modulation of memory T cell chemokinesis is a key mechanism by which this molecule contributes to the homeostatic regulation of effector T cell immunity.

  11. The Role of Lymphatic Niches in T Cell Differentiation

    Science.gov (United States)

    Capece, Tara; Kim, Minsoo

    2016-01-01

    Long-term immunity to many viral and bacterial pathogens requires CD8+ memory T cell development, and the induction of long-lasting CD8+ memory T cells from a naïve, undifferentiated state is a major goal of vaccine design. Formation of the memory CD8+ T cell compartment is highly dependent on the early activation cues received by naïve CD8+ T cells during primary infection. This review aims to highlight the cellularity of various niches within the lymph node and emphasize recent evidence suggesting that distinct types of T cell activation and differentiation occur within different immune contexts in lymphoid organs. PMID:27306645

  12. CD8+ T cells in inflammatory demyelinating disease

    DEFF Research Database (Denmark)

    Weiss, Hanne A; Millward, Jason M; Owens, Trevor

    2007-01-01

    We review the contribution made by CD8+ T cells to inflammation in the central nervous system (CNS) in Multiple Sclerosis (MS), and discuss their role in the animal model Experimental Autoimmune Encephalomyelitis (EAE). We show that the inflammatory cytokines interferon-gamma and interleukin-17...... are differentially regulated in CNS-infiltrating CD4+ and CD8+ T cells in EAE, and that CD8+ T cells regulate disease. In MS, CD8+ T cells appear to play a role in promotion of disease, so cytokine regulation is likely different in CD8+ T cells in MS and EAE...

  13. Chimeric antigen receptor T-cell therapy for solid tumors

    Directory of Open Access Journals (Sweden)

    Kheng Newick

    2016-01-01

    Full Text Available Chimeric antigen receptor (CAR T cells are engineered constructs composed of synthetic receptors that direct T cells to surface antigens for subsequent elimination. Many CAR constructs are also manufactured with elements that augment T-cell persistence and activity. To date, CAR T cells have demonstrated tremendous success in eradicating hematological malignancies (e.g., CD19 CARs in leukemias. This success is not yet extrapolated to solid tumors, and the reasons for this are being actively investigated. Here in this mini-review, we discuss some of the key hurdles encountered by CAR T cells in the solid tumor microenvironment.

  14. Genetic Engineering of T Cells to Target HERV-K, an Ancient Retrovirus on Melanoma.

    Science.gov (United States)

    Krishnamurthy, Janani; Rabinovich, Brian A; Mi, Tiejuan; Switzer, Kirsten C; Olivares, Simon; Maiti, Sourindra N; Plummer, Joshua B; Singh, Harjeet; Kumaresan, Pappanaicken R; Huls, Helen M; Wang-Johanning, Feng; Cooper, Laurence J N

    2015-07-15

    The human endogenous retrovirus (HERV-K) envelope (env) protein is a tumor-associated antigen (TAA) expressed on melanoma but not normal cells. This study was designed to engineer a chimeric antigen receptor (CAR) on T-cell surface, such that they target tumors in advanced stages of melanoma. Expression of HERV-K protein was analyzed in 220 melanoma samples (with various stages of disease) and 139 normal organ donor tissues using immunohistochemical (IHC) analysis. HERV-K env-specific CAR derived from mouse monoclonal antibody was introduced into T cells using the transposon-based Sleeping Beauty (SB) system. HERV-K env-specific CAR(+) T cells were expanded ex vivo on activating and propagating cells (AaPC) and characterized for CAR expression and specificity. This includes evaluating the HERV-K-specific CAR(+) T cells for their ability to kill A375-SM metastasized tumors in a mouse xenograft model. We detected HERV-K env protein on melanoma but not in normal tissues. After electroporation of T cells and selection on HERV-K(+) AaPC, more than 95% of genetically modified T cells expressed the CAR with an effector memory phenotype and lysed HERV-K env(+) tumor targets in an antigen-specific manner. Even though there is apparent shedding of this TAA from tumor cells that can be recognized by HERV-K env-specific CAR(+) T cells, we observed a significant antitumor effect. Adoptive cellular immunotherapy with HERV-K env-specific CAR(+) T cells represents a clinically appealing treatment strategy for advanced-stage melanoma and provides an approach for targeting this TAA on other solid tumors. ©2015 American Association for Cancer Research.

  15. Cytomegalovirus (CMV) Epitope-Specific CD4+ T Cells Are Inflated in HIV+ CMV+ Subjects.

    Science.gov (United States)

    Abana, Chike O; Pilkinton, Mark A; Gaudieri, Silvana; Chopra, Abha; McDonnell, Wyatt J; Wanjalla, Celestine; Barnett, Louise; Gangula, Rama; Hager, Cindy; Jung, Dae K; Engelhardt, Brian G; Jagasia, Madan H; Klenerman, Paul; Phillips, Elizabeth J; Koelle, David M; Kalams, Spyros A; Mallal, Simon A

    2017-11-01

    Select CMV epitopes drive life-long CD8 + T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4 + T cells specific for human CMV (HCMV) are elevated in HIV + HCMV + subjects. To determine whether HCMV epitope-specific CD4 + T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4 + T cells in coinfected HLA-DR7 + long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4 + T cells were inflated among these HIV + subjects compared with those from an HIV - HCMV + HLA-DR7 + cohort or with HLA-DR7-restricted CD4 + T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4 + T cells consisted of effector memory or effector memory-RA + subsets with restricted TCRβ usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX 3 CR1, CD38, or HLA-DR but less often coexpressed CD38 + and HLA-DR + The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4 + T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease. Copyright © 2017 by The American Association of Immunologists, Inc.

  16. Inhibition of apoptosis in T cells expressing human T cell leukemia virus type I Tax

    NARCIS (Netherlands)

    Copeland, K. F.; Haaksma, A. G.; Goudsmit, J.; Krammer, P. H.; Heeney, J. L.

    1994-01-01

    This study set out to determine whether T cell dysfunction associated with HTLV-I led to increased sensitivity of infected cells to apoptosis or, owing to their potential to develop ATL, if infected cells would become resistant to this process. To test this hypothesis we utilized the monoclonal

  17. MMP19 is essential for T cell development and T cell-mediated cutaneous immune responses

    Czech Academy of Sciences Publication Activity Database

    Beck, Inken; Ruckert, R.; Brandt, K.; Mueller, M.S.; Sadowski, T.; Brauer, R.; Schirmacher, P.; Mentlein, R.; Sedláček, Radislav

    2008-01-01

    Roč. 3, č. 6 (2008), e2343-e2343 E-ISSN 1932-6203 Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z50520701 Keywords : matrix metalloproteinase * T cell * immune response Subject RIV: EB - Genetics ; Molecular Biology

  18. Green tea EGCG, T-cell function, and T-cell-mediated autoimmune encephalomyelitis

    Science.gov (United States)

    Autoimmune diseases are common, disabling immune disorders affecting millions of people. Recent studies indicate that dysregulated balance of different CD4+ T-cell subpopulations plays a key role in immune pathogenesis of several major autoimmune diseases. Green tea and its active ingredient, epigal...

  19. ImmunoPET Imaging of Murine CD4+ T Cells Using Anti-CD4 Cys-Diabody: Effects of Protein Dose on T Cell Function and Imaging.

    Science.gov (United States)

    Freise, Amanda C; Zettlitz, Kirstin A; Salazar, Felix B; Lu, Xiang; Tavaré, Richard; Wu, Anna M

    2017-08-01

    Molecular imaging of CD4 + T cells throughout the body has implications for monitoring autoimmune disease and immunotherapy of cancer. Given the key role of these cells in regulating immunity, it is important to develop a biologically inert probe. GK1.5 cys-diabody (cDb), a previously developed anti-mouse CD4 antibody fragment, was tested at different doses to assess its effects on positron emission tomography (PET) imaging and CD4 + T cell viability, proliferation, CD4 expression, and function. The effect of protein dose on image contrast (lymphoid tissue-to-muscle ratio) was assessed by administering different amounts of 89 Zr-labeled GK1.5 cDb to mice followed by PET imaging and ex vivo biodistribution analysis. To assess impact of GK1.5 cDb on T cell biology, GK1.5 cDb was incubated with T cells in vitro or administered intravenously to C57BL/6 mice at multiple protein doses. CD4 expression and T cell proliferation were analyzed with flow cytometry and cytokines were assayed. For immunoPET imaging, the lowest protein dose of 2 μg of 89 Zr-labeled GK1.5 cDb resulted in significantly higher % injected dose/g in inguinal lymph nodes (ILN) and spleen compared to the 12-μg protein dose. In vivo administration of GK1.5 cDb at the high dose of 40 μg caused a transient decrease in CD4 expression in spleen, blood, lymph nodes, and thymus, which recovered within 3 days postinjection; this effect was reduced, although not abrogated, when 2 μg was administered. Proliferation was inhibited in vivo in ILN but not the spleen by injection of 40 μg GK1.5 cDb. Concentrations of GK1.5 cDb in excess of 25 nM significantly inhibited CD4 + T cell proliferation and interferon-γ production in vitro. Overall, using low-dose GK1.5 cDb minimized biological effects on CD4 + T cells. Low-dose GK1.5 cDb yields high-contrast immunoPET images with minimal effects on T cell biology in vitro and in vivo and may be a useful tool for investigating CD4 + T cells in the context of

  20. Plasticity of regulatory T cells under cytokine pressure.

    Science.gov (United States)

    Diaconu, Carmen C; Neagu, Ana I; Lungu, Răzvan; Tardei, Graţiela; Alexiu, Irina; Bleotu, Coralia; Economescu, Mihaela Chivu; Bumbăcea, Roxana S; Pele, Irina; Bumbăcea, Dragoş

    2010-01-01

    CD4+ T helper (Th) cells have been divided into different subsets as defined by their cytokine products and functions after their activation. CD4+ T cell subsets are continuously discovered and until now Th1, Th2, Th9, Th17, and regulatory T (Treg) cells have been almost unanimously recognized but yet not completely characterized. The selective production of cytokines by each of the subsets is probably the master key of the mechanisms of immune regulation. The cytokine milieu is extremely important on deciding the fate of T cells. Generally, more than one cytokine is needed for differentiating to a particular lineage and just recently it was shown that this status quo of commitment could be challenged. It is well known that cytokines bind to Type I/II cytokine receptors signaling via Janus kinases (JAKs) followed by activation of Signal Transducer and Activator of Transcription (STAT). STAT molecules work together with other transcription factors (Foxp3, RORgammat and RORalpha, T-bet, GATA3, Runx 1, NFAT, etc.) also controlled by cytokines, in modulating the Th phenotype and functions. In this review, we analyze the plasticity of Treg population focusing on the most recent discoveries on how microenvironmental cytokines refine/modify Treg phenotype and function, thus changing their fate.

  1. Adoptive T cell therapy targeting CD1 and MR1

    Directory of Open Access Journals (Sweden)

    Tingxi eGuo

    2015-05-01

    Full Text Available Adoptive T cell immunotherapy has demonstrated clinically relevant efficacy in treating malignant and infectious diseases. However, much of these therapies have been focused on enhancing, or generating de novo, effector functions of conventional T cells recognizing HLA molecules. Given the heterogeneity of HLA alleles, mismatched patients are ineligible for current HLA-restricted adoptive T cell therapies. CD1 and MR1 are class I-like monomorphic molecules and their restricted T cells possess unique T cell receptor specificity against entirely different classes of antigens. CD1 and MR1 molecules present lipid and vitamin B metabolite antigens, respectively, and offer a new front of targets for T cell therapies. This review will cover the recent progress in the basic research of CD1, MR1, and their restricted T cells that possess translational potential.

  2. Resonance absorption spectroscopy for laser-ablated lanthanide atom. (1) Optimized experimental conditions for isotope-selective absorption of gadolinium (Contract research)

    International Nuclear Information System (INIS)

    Miyabe, Masabumi; Oba, Masaki; Iimura, Hideki; Akaoka, Katsuaki; Maruyama, Yoichiro; Wakaida, Ikuo; Watanabe, Kazuo

    2008-06-01

    For remote isotope analysis of low-decontaminated TRU fuel, we are developing an analytical technique on the basis of the resonance absorption spectroscopy for the laser-ablation plume. To improve isotopic selectivity and detection sensitivity of this technique, we measured absorption spectra of Gd atom with various plume production conditions (ablation laser intensity, ambient gas and its pressure) and observation conditions (transition, probe height from sample, observation timing). As a result, high resolution spectrum was obtained from the observation of slow component of the plume produced under low-pressure rare-gas ambient. The observed narrowest linewidth of about 0.85GHz was found to be close to the Doppler width estimated for Gd atom of room temperature. Furthermore, relaxation rate of higher meta-stable state was found to be higher than that of ground state, suggesting that use of the transition arising from ground state or lower meta-stable state is preferable for highly sensitive isotope analysis. (author)

  3. To investigate the necessity of STRA6 upregulation in T cells during T cell immune responses.

    Directory of Open Access Journals (Sweden)

    Rafik Terra

    Full Text Available Our earlier study revealed that STRA6 (stimulated by retinoic acid gene 6 was up-regulated within 3 h of TCR stimulation. STRA6 is the high-affinity receptor for plasma retinol-binding protein (RBP and mediates cellular vitamin A uptake. We generated STRA6 knockout (KO mice to assess whether such up-regulation was critical for T-cell activation, differentiation and function. STRA6 KO mice under vitamin A sufficient conditions were fertile without apparent anomalies upon visual inspection. The size, cellularity and lymphocyte subpopulations of STRA6 KO thymus and spleen were comparable to those of their wild type (WT controls. KO and WT T cells were similar in terms of TCR-stimulated proliferation in vitro and homeostatic expansion in vivo. Naive KO CD4 cells differentiated in vitro into Th1, Th2, Th17 as well as regulatory T cells in an analogous manner as their WT counterparts. In vivo experiments revealed that anti-viral immune responses to lymphocytic choriomeningitis virus in KO mice were comparable to those of WT controls. We also demonstrated that STRA6 KO and WT mice had similar glucose tolerance. Total vitamin A levels are dramatically lower in the eyes of KO mice as compared to those of WT mice, but the levels in other organs were not significantly affected after STRA6 deletion under vitamin A sufficient conditions, indicating that the eye is the mouse organ most sensitive to the loss of STRA6. Our results demonstrate that 1 in vitamin A sufficiency, the deletion of STRA6 in T cells does no affect the T-cell immune responses so-far tested, including those depend on STAT5 signaling; 2 STRA6-independent vitamin A uptake compensated the lack of STRA6 in lymphoid organs under vitamin A sufficient conditions in mice; 3 STRA6 is critical for vitamin A uptake in the eyes even in vitamin A sufficiency.

  4. Is psoriasis a T-cell disease?

    Science.gov (United States)

    Nickoloff, B J; Schröder, J M; von den Driesch, P; Raychaudhuri, S P; Farber, E M; Boehncke, W H; Morhenn, V B; Rosenberg, E W; Schön, M P; Holick, M F

    2000-10-01

    The etiology and pathogenesis of psoriasis--one of the most common chronic, inflammatory, hyperproliferative skin disorders of man--have long fascinated dermatologists, pathologists and biologists alike. Here, we have a model disease that offers to study neuroectodermal-mesenchymal interactions in the widest sense possible. Epithelial, endothelial, and hematopoietic cells as well as neurons projecting into the skin apparently all interact with each other to generate the characteristic psoriatic lesion. For decades, the ongoing controversy on the molecular nature, choreography and hierarchy of these complex interactions e.g. between epidermal keratinocytes, T cells, neurotrophils, endothelial cells and sensory nerves has served as a driving force propelling investigative dermatology to ever new horizons. This debate has not only been at the heart of our quest to develop more effective forms of therapy for this socially crippling disease, but it also has profoundly influenced how we view the skin as a whole: the numerous competing theories on the pathogenesis of psoriasis published so far also are reflections on the evolution of mainstream thought in skin biology over the last decades. These days, conventional wisdom infatuated with a T-cell-centered approach to inflammatory skin diseases-- portrays psoriasis as an autoimmune disease, where misguided T lymphocyte activities cause secondary epithelial abnormalities. And yet, as this CONTROVERSIES feature reminds us, some authoritative "pockets of academic resistance" are still quite alive, and interpret psoriasis e.g. as a genetically determined, abnormal epithelial response pattern to infectious and/or physicochemical skin insults. Weighing the corresponding lines of argumentation is not only an intriguing, clinically relevant intellectual exercise, but also serves as a wonderful instrument for questioning our own views of the skin universe and its patterns of deviation from a state of homeostasis.

  5. Automated Cell Enrichment of Cytomegalovirus-specific T cells for Clinical Applications using the Cytokine-capture System.

    Science.gov (United States)

    Kumaresan, Pappanaicken; Figliola, Mathew; Moyes, Judy S; Huls, M Helen; Tewari, Priti; Shpall, Elizabeth J; Champlin, Richard; Cooper, Laurence J N

    2015-10-05

    The adoptive transfer of pathogen-specific T cells can be used to prevent and treat opportunistic infections such as cytomegalovirus (CMV) infection occurring after allogeneic hematopoietic stem-cell transplantation. Viral-specific T cells from allogeneic donors, including third party donors, can be propagated ex vivo in compliance with current good manufacturing practice (cGMP), employing repeated rounds of antigen-driven stimulation to selectively propagate desired T cells. The identification and isolation of antigen-specific T cells can also be undertaken based upon the cytokine capture system of T cells that have been activated to secrete gamma-interferon (IFN-γ). However, widespread human application of the cytokine capture system (CCS) to help restore immunity has been limited as the production process is time-consuming and requires a skilled operator. The development of a second-generation cell enrichment device such as CliniMACS Prodigy now enables investigators to generate viral-specific T cells using an automated, less labor-intensive system. This device separates magnetically labeled cells from unlabeled cells using magnetic activated cell sorting technology to generate clinical-grade products, is engineered as a closed system and can be accessed and operated on the benchtop. We demonstrate the operation of this new automated cell enrichment device to manufacture CMV pp65-specific T cells obtained from a steady-state apheresis product obtained from a CMV seropositive donor. These isolated T cells can then be directly infused into a patient under institutional and federal regulatory supervision. All the bio-processing steps including removal of red blood cells, stimulation of T cells, separation of antigen-specific T cells, purification, and washing are fully automated. Devices such as this raise the possibility that T cells for human application can be manufactured outside of dedicated good manufacturing practice (GMP) facilities and instead be produced

  6. Regulatory T cells (Treg and Their Roles in Immune System with Respect to Immunopathological Disorders

    Directory of Open Access Journals (Sweden)

    Kateřina Kondělková

    2010-01-01

    Full Text Available Regulatory T cells (Tregs are a specialized subpopulation of T cells that act to suppress immune response, thereby maintaining homeostasis and self-tolerance. It has been shown that Tregs are able to inhibit T cell proliferation and cytokine production and play a critical role in preventing autoimmunity. Different subsets with various functions of Treg cells exist. Tregs can be usually identified by flow cytometry. The most specific marker for these cells is FoxP3, which is localized intracellulary. Selected surface markers such as CD25high (high molecular density and CD127low (low molecular density could serve as surrogate markers to detect Tregs in a routine clinical practice. Dysregulation in Treg cell frequency or functions may lead to the development of autoimmune disease. Therapeutical Treg modulation is considered to be a promising therapeutical approach to treat some selected disorders, such as allergies, and to prevent allograft rejection.

  7. Thymopoiesis and regulatory T cells in healthy children and adolescents

    Directory of Open Access Journals (Sweden)

    Maria Izabel Arismendi

    2012-01-01

    Full Text Available OBJECTIVES: The purpose of this study was to investigate the association between T cell receptor excision circle levels in peripheral blood mononuclear cells and regulatory T cells that co-express CD25 and Foxp3 in healthy children and adolescents of different ages. MATERIALS AND METHODS: The quantification of signal-joint T-cell receptor excision circle levels in the genomic DNA of peripheral blood mononuclear cells was performed using real-time quantitative PCR. The analysis of CD4, CD8, CD25, and Foxp3 expression was performed using flow cytometry. RESULTS: Ninety-five healthy controls (46 females and 49 males ranging in age from 1 to 18 years were analyzed. The mean T-cell receptor excision circle count in all individuals was 89.095¡36.790 T-cell receptor excision circles per microgram of DNA. There was an inverse correlation between T-cell receptor excision circles counts and age (r = -0.846; p<0.001 as well as between the proportion of CD4+CD25+Foxp3+ T cells and age (r = -0.467; p = 0.04. In addition, we observed a positive correlation between the amount of CD4+CD25+Foxp3+ T cells and the amount of Tcell receptor excision circles per microgram of DNA in individuals of all ages (r = -0.529; p = 0.02. CONCLUSIONS: In this study, we observed a decrease in the thymic function with age based on the fact that the level of T-cell receptor excision circles in the peripheral blood positively correlated with the proportion of regulatory T cells in healthy children and adolescents. These findings indicate that although T-cell receptor excision circles and regulatory T cells levels decrease with age, homeostasis of the immune system and relative regulatory T cells population levels are maintained in the peripheral blood.

  8. Suppression of T cell-induced osteoclast formation

    Energy Technology Data Exchange (ETDEWEB)

    Karieb, Sahar; Fox, Simon W., E-mail: Simon.fox@plymouth.ac.uk

    2013-07-12

    Highlights: •Genistein and coumestrol prevent activated T cell induced osteoclast formation. •Anti-TNF neutralising antibodies prevent the pro-osteoclastic effect of activated T cells. •Phytoestrogens inhibit T cell derived TNF alpha and inflammatory cytokine production. •Phytoestrogens have a broader range of anti-osteoclastic actions than other anti-resorptives. -- Abstract: Inhibition of T cell derived cytokine production could help suppress osteoclast differentiation in inflammatory skeletal disorders. Bisphosphonates are typically prescribed to prevent inflammatory bone loss but are not tolerated by all patients and are associated with an increased risk of osteonecrosis of the jaw. In light of this other anti-resorptives such as phytoestrogens are being considered. However the effect of phytoestrogens on T cell-induced osteoclast formation is unclear. The effect of genistein and coumestrol on activated T cell-induced osteoclastogenesis and cytokine production was therefore examined. Concentrations of genistein and coumestrol (10{sup −7} M) previously shown to directly inhibit osteoclast formation also suppressed the formation of TRAP positive osteoclast induced by con A activated T cells, which was dependent on inhibition of T cell derived TNF-α. While both reduced osteoclast formation their mechanism of action differed. The anti-osteoclastic effect of coumestrol was associated with a dual effect on con A induced T cell proliferation and activation; 10{sup −7} M coumestrol significantly reducing T cell number (0.36) and TNF-α (0.47), IL-1β (0.23) and IL-6 (0.35) expression, whereas genistein (10{sup −7} M) had no effect on T cell number but a more pronounced effect on T cell differentiation reducing expression of TNF-α (0.49), IL-1β (0.52), IL-6 (0.71) and RANKL (0.71). Phytoestrogens therefore prevent the pro-osteoclastic action of T cells suggesting they may have a role in the control of inflammatory bone loss.

  9. An innovative method to selectively ablate cholesterol esters from an arteriosclerotic region of the arterial wall using a free-electron laser

    International Nuclear Information System (INIS)

    Awazu, K.; Nagai, A.; Tomimasu, T.; Aizawa, K.

    1998-01-01

    The selective removal of cholesterol esters accumulated in the intra-cellular or extra-cellular spaces has clinical significance. In the present work we investigate the removal of cholesterol esters by using a free electron laser (FEL) in an arteriosclerotic region. Thin films of cholesteryl oleate and albumin, and the cross-section of a rabbit artery were placed on an inverted microscope stage and the changes caused by the FEL irradiation of 5.75 and 6.1 μm with 1.5-3 mW in average were monitored continuously by a CCD camera in real time. FEL irradiation at a wavelength of 5.75 μm, which is a stretching vibrational mode of the ester, was able to ablate cholesterol esters without affecting albumin and that it can also remove cholesterol esters from rabbits' arteriosclerotic arterial walls. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  10. Studies on the mechanism of the self restriction of T cell responses in radiation chimeras

    International Nuclear Information System (INIS)

    Fink, P.J.; Bevan, M.J.

    1981-01-01

    Recent experiments with murine radiation chimeras have shown that F 1 T cells that mature in an H-2 homozygous thymus, as is the case in [F 1 → Parent 1] chimeras, are restricted to recognizing foreign antigen in the context of Parent 1 H-2 antigens. Conflicting results on the stringency of self H-2 restriction of T cells from normal mice have suggested that the thymic restriction in chimeras may be due to active suppression of parent 2-restricted T cell clones. We have therefore conducted 3 sets of experiments to test for suppression of maturing T cells that could mediate thymic tutoring of H-2-restriction specificity in chimeras. In 2 sets of experiments, we found no evidence that suppressor cells could be exported from 1 thymus and act either intrathymically on thymocytes in a 2nd thymus or extrathymically on recent thymic emigrants. We believe current data support a role for the thymus in positive as well as negative selection of maturing thymocytes on the basis of self recognition, in the absence of any suppression. Our results do not support the concept that suppression is responsible for the difference in the degree of self preference in the T cells of chimeric mice relative to cell populations obtained from neonatally tolerant mice or from normal mice after acute negative selection

  11. HLA Class-II Associated HIV Polymorphisms Predict Escape from CD4+ T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Nathan Erdmann

    2015-08-01

    Full Text Available Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1 exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE or its non-adapted (NAE version were evaluated for immunogenicity. Using a CD8-depleted IFN-γ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p<0.0001. However, regardless of the group, the magnitude of responses to AE was lower as compared to NAE (p<0.0001. CD4+ T cell responses in patients with acute HIV infection (AHI demonstrated poor immunogenicity towards AE as compared to NAE encoded by their transmitted founder virus. Longitudinal data in AHI off antiretroviral therapy demonstrated sequence changes that were biologically confirmed to represent CD4+ escape mutations. These data demonstrate an innovative application of HLA-associated polymorphisms to identify biologically relevant CD4+ epitopes and suggests CD4+ T cells are active participants in driving HIV evolution.

  12. Structure determination of T-cell protein-tyrosine phosphatase

    DEFF Research Database (Denmark)

    Iversen, L.F.; Møller, K. B.; Pedersen, A.K.

    2002-01-01

    Protein-tyrosine phosphatase 1B (PTP1B) has recently received much attention as a potential drug target in type 2 diabetes. This has in particular been spurred by the finding that PTP1B knockout mice show increased insulin sensitivity and resistance to diet-induced obesity. Surprisingly, the highly...... homologous T cell protein-tyrosine phosphatase (TC-PTP) has received much less attention, and no x-ray structure has been provided. We have previously co-crystallized PTP1B with a number of low molecular weight inhibitors that inhibit TC-PTP with similar efficiency. Unexpectedly, we were not able to co...... the high degree of functional and structural similarity between TC-PTP and PTP1B, we have been able to identify areas close to the active site that might be addressed to develop selective inhibitors of each enzyme....

  13. Methods to Improve Adoptive T-Cell Therapy for Melanoma

    DEFF Research Database (Denmark)

    Donia, Marco; Hansen, Morten; Sendrup, Sarah L

    2013-01-01

    desirable. In this study, we demonstrated that a high in vitro tumor reactivity of infusion products was associated with clinical responses upon adoptive transfer. In addition, we systematically characterized the responses of a series of TIL products to relevant autologous short term-cultured melanoma cell...... lines from 12 patients. We provide evidence that antitumor reactivity of both CD8(+) and CD4(+) T cells could be enhanced in most TIL products by autologous melanoma sensitization by pretreatment with low-dose IFN-γ. IFN-γ selectively enhanced responses to tumor-associated antigens other than melanoma...... differentiation antigens. In addition, IFN-γ treatment was invariably associated with restored/increased cancer immunogenicity as demonstrated by upregulation of major histocompatibility complex molecules. These findings suggest a potential synergism between IFN-γ and ACT, and have important implications...

  14. Hyperoxia Inhibits T Cell Activation in Mice

    Science.gov (United States)

    Hughes-Fulford, M.; Meissler, J.; Aguayo, E. T.; Globus, R.; Aguado, J.; Candelario, T.

    2013-02-01

    , spleens were removed and the splenocytes were isolated and kept as individual biological samples. We have also examined transcription factors (JASPAR) and pathways of the immune system to help us understand the mechanism of regulation. Results: Our recent mouse immunology experiment aboard STS-131 suggests that the early T cell immune response was inhibited in animals that have been exposed to spaceflight, even 24 hours after return to earth. Moreover, recent experiments in hyperoxic mice show that many of the same genes involved in early T cell activation were altered. Specifically, expression of IL-2Rα, Cxcl2, TNFα, FGF2, LTA and BCL2 genes are dysregulated in mice exposed to hyperoxia. Conclusions: If these hyperoxia-induced changes of gene expression in early T cell activation are additive to the changes seen in the microgravity of spaceflight, there could be an increased infection risk to EVA astronauts, which should be addressed prior to conducting a Mars or other long-term mission.

  15. Psoriasis associated with idiopathic CD4+ T-cell lymphopenia: a regulatory T-cell defect?

    Science.gov (United States)

    Baroudjian, B; Viguier, M; Battistella, M; Beneton, N; Pagès, C; Gener, G; Bégon, E; Bachelez, H

    2014-07-01

    Idiopathic CD4(+) lymphocytopenia (ICL) is a rare immunodeficiency syndrome of unknown origin for which the increased risks of opportunistic infections and of malignancies have been well established; however, skin dysimmune diseases, including psoriasis, have been scarcely reported up to now. We report herein the severe course of psoriasis in four patients with ICL, and show evidence for a defect in the skin recruitment of regulatory CD4(+) FoxP3(+) T cells. These data raise the apparent paradigm of the occurrence of a severe immunomediated disease together with a profound T-cell defect, a model that might also apply to other immune deficiencies associated with psoriasis. © 2014 British Association of Dermatologists.

  16. CD4+ T-cell lines used to evaluate a Mycobacterium avium subsp. paratuberculosis (MAP) peptide vaccine

    DEFF Research Database (Denmark)

    Lybeck, Kari; Sjurseth, Siri K.; Al-Touama, Zainab

    The aim of the study was to establish a protocol for generation of MAP-specific T-cell lines and to use these lines for evaluation of a peptide vaccine. A protocol for culturing T-cell lines from peripheral blood of goats naturally infected with MAP was established. CD4+ T cells were positively...... selected using an anti CD4 mAb and Dynabeads. Sorted CD4+ cells were cultivated with purified protein derivative from MAP (PPDj) or E. coli sonicate, IL-2, and IL-15. After two cultivation cycles, T cells were tested for recall responses in a proliferative T-cell assay. T-cell line responses were...... in average 92 % for PPDj, and -3 % for E. coli sonicate. CD4+ T-cell lines stimulated with PPDj showed a 6 fold increase in IFN- γ production compared to controls. These results indicated that the T-cell lines were MAP-specific. The protocol was subsequently used to evaluate MAP-specific peptides as vaccine...

  17. Chemotherapy and radiation therapy elicits tumor specific T cell responses in a breast cancer patient

    International Nuclear Information System (INIS)

    Bernal-Estévez, David; Sánchez, Ramiro; Tejada, Rafael E.; Parra-López, Carlos

    2016-01-01

    Experimental evidence and clinical studies in breast cancer suggest that some anti-tumor therapy regimens generate stimulation of the immune system that accounts for tumor clinical responses, however, demonstration of the immunostimulatory power of these therapies on cancer patients continues to be a formidable challenge. Here we present experimental evidence from a breast cancer patient with complete clinical response after 7 years, associated with responsiveness of tumor specific T cells. T cells were obtained before and after anti-tumor therapy from peripheral blood of a 63-years old woman diagnosed with ductal breast cancer (HER2/neu+++, ER-, PR-, HLA-A*02:01) treated with surgery, followed by paclitaxel, trastuzumab (suspended due to cardiac toxicity), and radiotherapy. We obtained a leukapheresis before surgery and after 8 months of treatment. Using in vitro cell cultures stimulated with autologous monocyte-derived dendritic cells (DCs) that produce high levels of IL-12, we characterize by flow cytometry the phenotype of tumor associated antigens (TAAs) HER2/neu and NY-ESO 1 specific T cells. The ex vivo analysis of the TCR-Vβ repertoire of TAA specific T cells in blood and Tumor Infiltrating Lymphocytes (TILs) were performed in order to correlate both repertoires prior and after therapy. We evidence a functional recovery of T cell responsiveness to polyclonal stimuli and expansion of TAAs specific CD8+ T cells using peptide pulsed DCs, with an increase of CTLA-4 and memory effector phenotype after anti-tumor therapy. The ex vivo analysis of the TCR-Vβ repertoire of TAA specific T cells in blood and TILs showed that whereas the TCR-Vβ04-02 clonotype is highly expressed in TILs the HER2/neu specific T cells are expressed mainly in blood after therapy, suggesting that this particular TCR was selectively enriched in blood after anti-tumor therapy. Our results show the benefits of anti-tumor therapy in a breast cancer patient with clinical complete response in

  18. Phenotypic and Functional Alterations in Circulating Memory CD8 T Cells with Time after Primary Infection.

    Directory of Open Access Journals (Sweden)

    Matthew D Martin

    2015-10-01

    Full Text Available Memory CD8 T cells confer increased protection to immune hosts upon secondary viral, bacterial, and parasitic infections. The level of protection provided depends on the numbers, quality (functional ability, and location of memory CD8 T cells present at the time of infection. While primary memory CD8 T cells can be maintained for the life of the host, the full extent of phenotypic and functional changes that occur over time after initial antigen encounter remains poorly characterized. Here we show that critical properties of circulating primary memory CD8 T cells, including location, phenotype, cytokine production, maintenance, secondary proliferation, secondary memory generation potential, and mitochondrial function change with time after infection. Interestingly, phenotypic and functional alterations in the memory population are not due solely to shifts in the ratio of effector (CD62Llo and central memory (CD62Lhi cells, but also occur within defined CD62Lhi memory CD8 T cell subsets. CD62Lhi memory cells retain the ability to efficiently produce cytokines with time after infection. However, while it is was not formally tested whether changes in CD62Lhi memory CD8 T cells over time occur in a cell intrinsic manner or are due to selective death and/or survival, the gene expression profiles of CD62Lhi memory CD8 T cells change, phenotypic heterogeneity decreases, and mitochondrial function and proliferative capacity in either a lymphopenic environment or in response to antigen re-encounter increase with time. Importantly, and in accordance with their enhanced proliferative and metabolic capabilities, protection provided against chronic LCMV clone-13 infection increases over time for both circulating memory CD8 T cell populations and for CD62Lhi memory cells. Taken together, the data in this study reveal that memory CD8 T cells continue to change with time after infection and suggest that the outcome of vaccination strategies designed to elicit

  19. Digoxin reveals a functional connection between HIV-1 integration preference and T-cell activation.

    Science.gov (United States)

    Zhyvoloup, Alexander; Melamed, Anat; Anderson, Ian; Planas, Delphine; Lee, Chen-Hsuin; Kriston-Vizi, Janos; Ketteler, Robin; Merritt, Andy; Routy, Jean-Pierre; Ancuta, Petronela; Bangham, Charles R M; Fassati, Ariberto

    2017-07-01

    HIV-1 integrates more frequently into transcribed genes, however the biological significance of HIV-1 integration targeting has remained elusive. Using a selective high-throughput chemical screen, we discovered that the cardiac glycoside digoxin inhibits wild-type HIV-1 infection more potently than HIV-1 bearing a single point mutation (N74D) in the capsid protein. We confirmed that digoxin repressed viral gene expression by targeting the cellular Na+/K+ ATPase, but this did not explain its selectivity. Parallel RNAseq and integration mapping in infected cells demonstrated that digoxin inhibited expression of genes involved in T-cell activation and cell metabolism. Analysis of >400,000 unique integration sites showed that WT virus integrated more frequently than N74D mutant within or near genes susceptible to repression by digoxin and involved in T-cell activation and cell metabolism. Two main gene networks down-regulated by the drug were CD40L and CD38. Blocking CD40L by neutralizing antibodies selectively inhibited WT virus infection, phenocopying digoxin. Thus the selectivity of digoxin depends on a combination of integration targeting and repression of specific gene networks. The drug unmasked a functional connection between HIV-1 integration and T-cell activation. Our results suggest that HIV-1 evolved integration site selection to couple its early gene expression with the status of target CD4+ T-cells, which may affect latency and viral reactivation.

  20. Digoxin reveals a functional connection between HIV-1 integration preference and T-cell activation.

    Directory of Open Access Journals (Sweden)

    Alexander Zhyvoloup

    2017-07-01

    Full Text Available HIV-1 integrates more frequently into transcribed genes, however the biological significance of HIV-1 integration targeting has remained elusive. Using a selective high-throughput chemical screen, we discovered that the cardiac glycoside digoxin inhibits wild-type HIV-1 infection more potently than HIV-1 bearing a single point mutation (N74D in the capsid protein. We confirmed that digoxin repressed viral gene expression by targeting the cellular Na+/K+ ATPase, but this did not explain its selectivity. Parallel RNAseq and integration mapping in infected cells demonstrated that digoxin inhibited expression of genes involved in T-cell activation and cell metabolism. Analysis of >400,000 unique integration sites showed that WT virus integrated more frequently than N74D mutant within or near genes susceptible to repression by digoxin and involved in T-cell activation and cell metabolism. Two main gene networks down-regulated by the drug were CD40L and CD38. Blocking CD40L by neutralizing antibodies selectively inhibited WT virus infection, phenocopying digoxin. Thus the selectivity of digoxin depends on a combination of integration targeting and repression of specific gene networks. The drug unmasked a functional connection between HIV-1 integration and T-cell activation. Our results suggest that HIV-1 evolved integration site selection to couple its early gene expression with the status of target CD4+ T-cells, which may affect latency and viral reactivation.

  1. Human T cell leukemia virus reactivation with progression of adult T-cell leukemia-lymphoma.

    Directory of Open Access Journals (Sweden)

    Lee Ratner

    Full Text Available Human T-cell leukemia virus-associated adult T-cell leukemia-lymphoma (ATLL has a very poor prognosis, despite trials of a variety of different treatment regimens. Virus expression has been reported to be limited or absent when ATLL is diagnosed, and this has suggested that secondary genetic or epigenetic changes are important in disease pathogenesis.We prospectively investigated combination chemotherapy followed by antiretroviral therapy for this disorder. Nineteen patients were prospectively enrolled between 2002 and 2006 at five medical centers in a phase II clinical trial of infusional chemotherapy with etoposide, doxorubicin, and vincristine, daily prednisone, and bolus cyclophosphamide (EPOCH given for two to six cycles until maximal clinical response, and followed by antiviral therapy with daily zidovudine, lamivudine, and alpha interferon-2a for up to one year. Seven patients were on study for less than one month due to progressive disease or chemotherapy toxicity. Eleven patients achieved an objective response with median duration of response of thirteen months, and two complete remissions. During chemotherapy induction, viral RNA expression increased (median 190-fold, and virus replication occurred, coincident with development of disease progression.EPOCH chemotherapy followed by antiretroviral therapy is an active therapeutic regimen for adult T-cell leukemia-lymphoma, but viral reactivation during induction chemotherapy may contribute to treatment failure. Alternative therapies are sorely needed in this disease that simultaneously prevent virus expression, and are cytocidal for malignant cells.

  2. Special regulatory T-cell review: T-cell dependent suppression revisited.

    Science.gov (United States)

    Basten, Antony; Fazekas de St Groth, Barbara

    2008-01-01

    The concept of T-cell dependent regulation of immune responses has been a central tenet of immunological thinking since the delineation of the two cell system in the 1960s. Indeed T-cell dependent suppression was discovered before MHC restriction. When reviewing the data from the original wave of suppression, it is intriguing to reflect not just on the decline and fall of suppressor T cells in the 1980s, but on their equally dramatic return to respectability over the past decade. Hopefully their resurgence will be supported by solid mechanistic data that will underpin their central place in our current and future understanding of the immune system. Cannon to right of them, Cannon to left of them, Cannon in front of them Volley'd and thunder'd Storm'd at with shot and shell, Boldly they rode and well, Into the jaws of Death, Into the mouth of Hell, Rode the six hundred (suppressionists). (Adapted from The Charge of the Light Brigade, Alfred, Lord Tennyson)

  3. CD4+/CD8+ double-positive T cells

    DEFF Research Database (Denmark)

    Overgaard, Nana H; Jung, Ji-Won; Steptoe, Raymond J

    2015-01-01

    CD4(+)/CD8(+) DP thymocytes are a well-described T cell developmental stage within the thymus. However, once differentiated, the CD4(+) lineage or the CD8(+) lineage is generally considered to be fixed. Nevertheless, mature CD4(+)/CD8(+) DP T cells have been described in the blood and peripheral...... cells, CD4(+)/CD8(+) T cell populations, outside of the thymus, have recently been described to express concurrently ThPOK and Runx3. Considerable heterogeneity exists within the CD4(+)/CD8(+) DP T cell pool, and the function of CD4(+)/CD8(+) T cell populations remains controversial, with conflicting...... reports describing cytotoxic or suppressive roles for these cells. In this review, we describe how transcriptional regulation, lineage of origin, heterogeneity of CD4 and CD8 expression, age, species, and specific disease settings influence the functionality of this rarely studied T cell population....

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

    Directory of Open Access Journals (Sweden)

    Nicholas Jones

    2017-11-01

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

  5. Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

    Science.gov (United States)

    Heit, Antje; Gebhardt, Friedemann; Lahl, Katharina; Neuenhahn, Michael; Schmitz, Frank; Anderl, Florian; Wagner, Hermann; Sparwasser, Tim; Busch, Dirk H; Kastenmüller, Kathrin

    2008-06-01

    Immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained CD8(+) T cell-mediated protection against intracellular pathogens. Most efforts to improve the CD8(+) T cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. In addition, it has been shown that CD4(+) T cell help during the priming phase contributes to the generation of protective CD8(+) memory T cells. In this report we demonstrate that the depletion of CD4(+) T cells paradoxically enhances long-lasting CD8-mediated protective immunity upon protein vaccination. Functional and genetic in vivo inactivation experiments attribute this enhancement primarily to MHC class II-restricted CD4(+) regulatory T cells (Treg), which appear to physiologically suppress the differentiation process towards long-living effector memory T cells. Since, in functional terms, this suppression by Treg largely exceeds the positive effects of conventional CD4(+) T cell help, even the absence of all CD4(+) T cells or lack of MHC class II-mediated interactions on priming dendritic cells result in enhanced CD8(+) T cell immunogenicity. These findings have important implications for the improvement of vaccines against intracellular pathogens or tumors, especially in patients with highly active Treg.

  6. Differentiation, distribution and gammadelta T cell-driven regulation of IL-22-producing T cells in tuberculosis.

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    Shuyu Yao

    2010-02-01

    Full Text Available Differentiation, distribution and immune regulation of human IL-22-producing T cells in infections remain unknown. Here, we demonstrated in a nonhuman primate model that M. tuberculosis infection resulted in apparent increases in numbers of T cells capable of producing IL-22 de novo without in vitro Ag stimulation, and drove distribution of these cells more dramatically in lungs than in blood and lymphoid tissues. Consistently, IL-22-producing T cells were visualized in situ in lung tuberculosis (TB granulomas by confocal microscopy and immunohistochemistry, indicating that mature IL-22-producing T cells were present in TB granuloma. Surprisingly, phosphoantigen HMBPP activation of Vgamma2Vdelta2 T cells down-regulated the capability of T cells to produce IL-22 de novo in lymphocytes from blood, lung/BAL fluid, spleen and lymph node. Up-regulation of IFNgamma-producing Vgamma2Vdelta2 T effector cells after HMBPP stimulation coincided with the down-regulated capacity of these T cells to produce IL-22 de novo. Importantly, anti-IFNgamma neutralizing Ab treatment reversed the HMBPP-mediated down-regulation effect on IL-22-producing T cells, suggesting that Vgamma2Vdelta2 T-cell-driven IFNgamma-networking function was the mechanism underlying the HMBPP-mediated down-regulation of the capability of T cells to produce IL-22. These novel findings raise the possibility to ultimately investigate the function of IL-22 producing T cells and to target Vgamma2Vdelta2 T cells for balancing potentially hyper-activating IL-22-producing T cells in severe TB.

  7. T Cell Subset and Stimulation Strength-Dependent Modulation of T Cell Activation by Kv1.3 Blockers.

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    Wai-Ping Fung-Leung

    Full Text Available Kv1.3 is a voltage-gated potassium channel expressed on T cells that plays an important role in T cell activation. Previous studies have shown that blocking Kv1.3 channels in human T cells during activation results in reduced calcium entry, cytokine production, and proliferation. The aim of the present study was to further explore the effects of Kv1.3 blockers on the response of different human T cell subsets under various stimulation conditions. Our studies show that, unlike the immune suppressor cyclosporine A, the inhibitory effect of Kv1.3 blockers was partial and stimulation strength dependent, with reduced inhibitory efficacy on T cells under strengthened anti-CD3/CD28 stimulations. T cell responses to allergens including house dust mites and ragweed were partially reduced by Kv1.3 blockers. The effect of Kv1.3 inhibition was dependent on T cell subsets, with stronger effects on CCR7- effector memory compared to CCR7+ central memory CD4 T cells. Calcium entry studies also revealed a population of CD4 T cells resistant to Kv1.3 blockade. Activation of CD4 T cells was accompanied with an increase in Kv1.3 currents but Kv1.3 transcripts were found to be reduced, suggesting a posttranscriptional mechanism in the regulation of Kv1.3 activities. In summary, Kv1.3 blockers inhibit T cell activation in a manner that is highly dependent on the T cell identity and stimulation strength, These findings suggest that Kv1.3 blockers inhibit T cells in a unique, conditional manner, further refining our understanding of the therapeutic potential of Kv1.3 blockers.

  8. Antigen specific T-cell responses against tumor antigens are controlled by regulatory T cells in patients with prostate cancer.

    Science.gov (United States)

    Hadaschik, Boris; Su, Yun; Huter, Eva; Ge, Yingzi; Hohenfellner, Markus; Beckhove, Philipp

    2012-04-01

    Immunotherapy is a promising approach in an effort to control castration resistant prostate cancer. We characterized tumor antigen reactive T cells in patients with prostate cancer and analyzed the suppression of antitumor responses by regulatory T cells. Peripheral blood samples were collected from 57 patients with histologically confirmed prostate cancer, 8 patients with benign prostatic hyperplasia and 16 healthy donors. Peripheral blood mononuclear cells were isolated and antigen specific interferon-γ secretion of isolated T cells was analyzed by enzyme-linked immunospot assay. T cells were functionally characterized and T-cell responses before and after regulatory T-cell depletion were compared. As test tumor antigens, a panel of 11 long synthetic peptides derived from a total of 8 tumor antigens was used, including prostate specific antigen and prostatic acid phosphatase. In patients with prostate cancer we noted a 74.5% effector T-cell response rate compared with only 25% in patients with benign prostatic hyperplasia and 31% in healthy donors. In most patients 2 or 3 tumor antigens were recognized. Comparing various disease stages there was a clear increase in the immune response against prostate specific antigens from intermediate to high risk tumors and castration resistant disease. Regulatory T-cell depletion led to a significant boost in effector T-cell responses against prostate specific antigen and prostatic acid phosphatase. Tumor specific effector T cells were detected in most patients with prostate cancer, especially those with castration resistant prostate cancer. Since effector T-cell responses against prostate specific antigens strongly increased after regulatory T-cell depletion, our results indicate that immunotherapy efficacy could be enhanced by decreasing regulatory T cells. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  9. Regulation of CD8+ T cell responses to retinal antigen by local FoxP3+ regulatory T cells

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    Scott W McPherson

    2012-06-01

    Full Text Available While pathogenic CD4 T cells are well known mediators of autoimmune uveoretinitis, CD8 T cells can also be uveitogenic. Since preliminary studies indicated that C57BL/6 mice were minimally susceptible to autoimmune uveoretinitis induction by CD8 T cells, the basis of the retinal disease resistance was sought. Mice that express β-galactosidase (βgal on a retina-specific promoter (arrβgal mice were backcrossed to mice expressing green fluorescent protein and diphtheria toxin receptor under control of the Foxp3 promoter (Foxp3-DTR/GFP mice, and to T cell receptor transgenic mice that produce βgal specific CD8 T cells (BG1 mice. These mice were used to explore the role of regulatory T cells in the resistance to retinal autoimmune disease. Experiments with T cells from double transgenic BG1 x Foxp3-DTR/GFP mice transferred into Foxp3-DTR/GFP x arrβgal mice confirmed that the retina was well protected from attempts to induce disease by adoptive transfer of activated BG1 T cells. The successful induction of retinal disease following unilateral intraocular administration of diphtheria toxin to deplete regulatory T cells showed that the protective activity was dependent on local, toxin-sensitive regulatory T cells; the opposite, untreated eye remained disease-free. Although there were very few Foxp3+ regulatory T cells in the parenchyma of quiescent retina, and they did not accumulate in retina, their depletion by local toxin administration led to disease susceptibility. We propose that these regulatory T cells modulate the pathogenic activity of βgal-specific CD8 T cells in the retinas of arrβgal mice on a local basis, allowing immunoregulation to be responsive to local conditions.

  10. Regulatory T cells and immunity to pathogens.

    Science.gov (United States)

    Rouse, Barry T; Suvas, Susmit

    2007-09-01

    Immune responses to pathogens are modulated by one or more types of cells that perform a regulatory function. Some cells with this function, such as CD4+ Foxp3+ natural regulatory T cells (nTreg), pre-exist prior to infections whereas others may be induced as a consequence of infection (adaptive Treg). With pathogens that have a complex pathogenesis, multiple types of regulatory cells could influence the outcome. One major property of Treg is to help minimize collateral tissue damage that can occur during immune reactions to a chronic infection. The consequence is less damage to the host but in such situations the pathogen is likely to establish persistence. In some cases, a fine balance is established between Treg responses, effector components of immunity and the pathogen. Treg responses to pathogens may also act to hamper the efficacy of immune control. This review discusses these issues as well as the likely mechanisms by which various pathogens can signal the participation of Treg during infection.

  11. Therapeutic options in peripheral T cell lymphoma

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    Yaping Zhang

    2016-04-01

    Full Text Available Abstract Peripheral T cell lymphoma (PTCL is a rare and heterogeneous group of non-Hodgkin lymphomas with a very poor prognosis. The standard first-line treatments have resulted in unsatisfactory patient outcomes. With the exception of low-risk anaplastic lymphoma kinase (ALK-positive anaplastic large cell lymphoma (ALCL, the majority of patients relapse rapidly; the current 5-year overall survival rates are only 10–30 %. Novel targeted therapies and combination chemotherapies are required for the treatment of patients with PTCL. In recent years, some retrospective and prospective studies have been performed concerning PTCL. Consequently, a number of novel agents and their relevant combination therapies have been identified, including histone deacetylase inhibitors, immunoconjugates, antifolates, monoclonal antibodies, immunomodulatory agents, nucleoside analogs, proteasome inhibitors, kinase inhibitors, bendamustine, l-asparaginase, and other targeted agents. It is hoped that these innovative approaches will finally improve outcomes in patients with PTCL. This review summarizes the currently available approaches for the treatment of PTCL with an emphasis on potential new agents, including the role of stem cell transplantation.

  12. Case report 429: Adult T-cell leukemia (ATL)

    International Nuclear Information System (INIS)

    Aoki, Jun; Yamamoto, Itsuo; Hino, Megumu; Torizuka, Kanji; Kyoto Univ.; Uchiyama, Takahashi; Uchino, Haruto

    1987-01-01

    The radiological and pathological skeletal manifestations in a case of adult T-cell leukemia are presented. The authors have emphasized the presence of multiple areas of localized subperiosteal resorption as a helpful finding in the differential diagnosis between adult T-cell leukemia and multiple myeloma and hyperparathyroidism. A possible mechanism for these radiological features and its similarity to those of other T-cell malignancies are discussed briefly. (orig./SHA)

  13. T Cells in Gastric Cancer: Friends or Foes

    Science.gov (United States)

    Amedei, Amedeo; Della Bella, Chiara; Silvestri, Elena; Prisco, Domenico; D'Elios, Mario M.

    2012-01-01

    Gastric cancer is the second cause of cancer-related deaths worldwide. Helicobacter pylori is the major risk factor for gastric cancer. As for any type of cancer, T cells are crucial for recognition and elimination of gastric tumor cells. Unfortunately T cells, instead of protecting from the onset of cancer, can contribute to oncogenesis. Herein we review the different types, “friend or foe”, of T-cell response in gastric cancer. PMID:22693525

  14. Clinical trials of CAR-T cells in China

    OpenAIRE

    Bingshan Liu; Yongping Song; Delong Liu

    2017-01-01

    Abstract Novel immunotherapeutic agents targeting tumor-site microenvironment are revolutionizing cancer therapy. Chimeric antigen receptor (CAR)-engineered T cells are widely studied for cancer immunotherapy. CD19-specific CAR-T cells, tisagenlecleucel, have been recently approved for clinical application. Ongoing clinical trials are testing CAR designs directed at novel targets involved in hematological and solid malignancies. In addition to trials of single-target CAR-T cells, simultaneous...

  15. Senescent T-Cells Promote Bone Loss in Rheumatoid Arthritis

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    Johannes Fessler

    2018-02-01

    Full Text Available ObjectiveT-cells are critical players in the pathogenesis of osteoporosis in patients with rheumatoid arthritis (RA. Premature senescence of lymphocytes including the accumulation of senescent CD4+ T-cells is a hallmark feature of RA. Whether T-cell senescence is associated with bone loss in RA patients is elusive so far.MethodsThis includes a prospective study of consecutive patients with RA (n = 107, patients with primary osteopenia/-porosis (n = 75, and healthy individuals (n = 38. Bone mineral density (BMD was determined by dual-energy X-ray absorptiometry scan. Flow cytometry, magnetic-associated cell sorting, and cell culture experiments were performed to analyze the pro-osteoclastic phenotype and the function of senescent CD4+CD28− T-cells.ResultsPatients with osteopenia/-porosis yielded a higher prevalence of senescent CD4+CD28− T-cells than individuals with normal BMD, in the RA, as well as in the non-RA cohort. Receptor activator of nuclear factor kappa-B ligand (RANKL was expressed at higher levels on CD4+CD28− T-cells as compared to CD28+ T-cells. Stimulation with interleukin-15 led to an up-regulation of RANKL expression, particularly on CD28− T-cells. CD4+CD28− T-cells induced osteoclastogenesis more efficiently than CD28+ T-cells.ConclusionOur data indicate that senescent T-cells promote osteoclastogenesis more efficiently than conventional CD28+ T-cells, which might contribute to the pathogenesis of systemic bone loss in RA and primary osteoporosis.

  16. Retinoic acid signalling in thymocytes regulates T cell development

    DEFF Research Database (Denmark)

    Wendland, Kerstin; Sitnik, Katarzyna Maria; Kotarsky, Knut

    in the regulatory regions of targetgenes. RA has been reported to play a direct role in regulating multiple aspects of peripheralT cell responses1, but whether endogenous RA signalling occurs in developingthymocytes and the potential impact of such signals in regulating T cell developmentremains unclear. To address......RARα. This blocks RA signalling in developing thymocytes from the DN3/4 stageonwards and thus allows us to study the role of RA in T cell development...

  17. Ibrutinib treatment improves T cell number and function in CLL patients.

    Science.gov (United States)

    Long, Meixiao; Beckwith, Kyle; Do, Priscilla; Mundy, Bethany L; Gordon, Amber; Lehman, Amy M; Maddocks, Kami J; Cheney, Carolyn; Jones, Jeffrey A; Flynn, Joseph M; Andritsos, Leslie A; Awan, Farrukh; Fraietta, Joseph A; June, Carl H; Maus, Marcela V; Woyach, Jennifer A; Caligiuri, Michael A; Johnson, Amy J; Muthusamy, Natarajan; Byrd, John C

    2017-08-01

    Ibrutinib has been shown to have immunomodulatory effects by inhibiting Bruton's tyrosine kinase (BTK) and IL-2-inducible T cell kinase (ITK). The relative importance of inhibiting these 2 kinases has not been examined despite its relevance to immune-based therapies. Peripheral blood mononuclear cells from chronic lymphocytic leukemia (CLL) patients on clinical trials of ibrutinib (BTK/ITK inhibitor; n = 19) or acalabrutinib (selective BTK inhibitor; n = 13) were collected serially. T cell phenotype, immune function, and CLL cell immunosuppressive capacity were evaluated. Ibrutinib markedly increased CD4+ and CD8+ T cell numbers in CLL patients. This effect was more prominent in effector/effector memory subsets and was not observed with acalabrutinib. Ex vivo studies demonstrated that this may be due to diminished activation-induced cell death through ITK inhibition. PD-1 and CTLA-4 expression was significantly markedly reduced in T cells by both agents. While the number of Treg cells remained unchanged, the ratio of these to conventional CD4+ T cells was reduced with ibrutinib, but not acalabrutinib. Both agents reduced expression of the immunosuppressive molecules CD200 and BTLA as well as IL-10 production by CLL cells. Ibrutinib treatment increased the in vivo persistence of activated T cells, decreased the Treg/CD4+ T cell ratio, and diminished the immune-suppressive properties of CLL cells through BTK-dependent and -independent mechanisms. These features provide a strong rationale for combination immunotherapy approaches with ibrutinib in CLL and other cancers. ClinicalTrials.gov NCT01589302 and NCT02029443. Samples described here were collected per OSU-0025. The National Cancer Institute.

  18. TCR down-regulation controls T cell homeostasis

    DEFF Research Database (Denmark)

    Boding, Lasse; Bonefeld, Charlotte Menné; Nielsen, Bodil L

    2009-01-01

    TCR and cytokine receptor signaling play key roles in the complex homeostatic mechanisms that maintain a relative stable number of T cells throughout life. Despite the homeostatic mechanisms, a slow decline in naive T cells is typically observed with age. The CD3gamma di-leucine-based motif...... controls TCR down-regulation and plays a central role in fine-tuning TCR expression and signaling in T cells. In this study, we show that the age-associated decline of naive T cells is strongly accelerated in CD3gammaLLAA knock-in mice homozygous for a double leucine to alanine mutation in the CD3gamma di......-leucine-based motif, whereas the number of memory T cells is unaffected by the mutation. This results in premature T cell population senescence with a severe dominance of memory T cells and very few naive T cells in middle-aged to old CD3gamma mutant mice. The reduced number of naive T cells in CD3gamma mutant mice...

  19. T-cell proliferative responses following sepsis in neonatal rats.

    Science.gov (United States)

    Dallal, Ousama; Ravindranath, Thyyar M; Choudhry, Mashkoor A; Kohn, Annamarie; Muraskas, Jonathan K; Namak, Shahla Y; Alattar, Mohammad H; Sayeed, Mohammed M

    2003-01-01

    Both experimental and clinical evidence suggest a suppression of T-cell function in burn and sepsis. The objective of the present study was to evaluate splenocyte and purified T-cell proliferative response and IL-2 production in septic neonatal rats. We also examined if alterations in T-cell proliferation and IL-2 production in neonatal sepsis is due to elevation in PGE2. PGE2 is known to play a significant role in T-cell suppression during sepsis in adults. Sepsis was induced in 15-day-old neonatal Sprague-Dawley rats by implanting 0.1 cm3 of fecal pellet impregnated with Escherichia coli (50 CFU) and Bacteroides fragilis (10(3) CFU). Animals receiving fecal pellets without the bacteria were designated as sterile. A group of septic and sterile rats were treated with PGE2 synthesis inhibitors, NS398 and resveratrol. These treatments of animals allowed us to evaluate the role of PGE2 in T-cell suppression during neonatal sepsis. Splenocytes as well as purified T cells were prepared and then proliferative response and IL-2 productive capacities were measured. A significant suppression of splenocyte proliferation and IL-2 production was noticed in both sterile and septic animals compared to the T cells from unoperated control rats. In contrast, the proliferation and IL-2 production by nylon wool purified T cells in sterile rats was not significantly different from control rats, whereas, a significant suppression in Con A-mediated T-cell proliferation and IL-2 production noticed in septic rat T cells compared to the sterile and control rat T cells. Such decrease in T-cell proliferation and IL-2 production was accompanied with 20-25% deaths in neonates implanted with septic pellets. No mortality was noted in sterile-implanted neonates. Treatment of animals with COX-1 inhibitor had no effect on T-cell proliferation response in both septic and sterile groups, whereas COX-2 inhibitor abrogated the decrease in T-cell proliferative response in the septic group. The treatment

  20. Chronic Inflammation and  T Cells

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    Nathan S Fay

    2016-05-01

    Full Text Available The epithelial tissues of the skin, lungs, reproductive tract, and intestines are the largest physical barriers the body has to protect against infection. Epithelial tissues are woven with a matrix of immune cells programmed to mobilize the host innate and adaptive immune responses. Included among these immune cells are  T cells that are unique in their TCR usage, location, and functions in the body. Stress reception by  T cells as a result of traumatic epithelial injury, malignancy, and/or infection induces  T cell activation. Once activated,  T cells function to repair tissue, induce inflammation, recruit leukocytes, and lyse cells. Many of these functions are mediated via the production of cytokines and growth factors upon  T cell activation. Pathogenesis of many chronic inflammatory diseases involve  T cells; some of which are exacerbated by their presence, while others are improved.  T cells require a delicate balance between their need for acute inflammatory mediators to function normally and the detrimental impact imparted by chronic inflammation. This review will focus on the recent progress made in understanding how epithelial  T cells influence the pathogenesis of chronic inflammatory diseases and how a balance between acute and chronic inflammation impacts  T cell function. Future studies will be important to understand how this balance is achieved.

  1. Early events governing memory CD8+ T-cell differentiation.

    Science.gov (United States)

    Obar, Joshua J; Lefrançois, Leo

    2010-08-01

    Understanding the regulation of the CD8(+) T-cell response and how protective memory cells are generated has been intensely studied. It is now appreciated that a naive CD8(+) T cell requires at least three signals to mount an effective immune response: (i) TCR triggering, (ii) co-stimulation and (iii) inflammatory cytokines. Only recently have we begun to understand the molecular integration of those signals and how early events regulate the fate decisions of the responding CD8(+) T cells. This review will discuss the recent findings about both the extracellular and intracellular factors that regulate the destiny of responding CD8(+) T cells.

  2. CD1 and mycobacterial lipids activate human T cells.

    Science.gov (United States)

    Van Rhijn, Ildiko; Moody, D Branch

    2015-03-01

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

  3. Ageing combines CD4 T cell lymphopenia in secondary lymphoid organs and T cell accumulation in gut associated lymphoid tissue.

    Science.gov (United States)

    Martinet, Kim Zita; Bloquet, Stéphane; Bourgeois, Christine

    2014-01-01

    CD4 T cell lymphopenia is an important T cell defect associated to ageing. Higher susceptibility to infections, cancer, or autoimmune pathologies described in aged individuals is thought to partly rely on T cell lymphopenia. We hypothesize that such diverse effects may reflect anatomical heterogeneity of age related T cell lymphopenia. Indeed, no data are currently available on the impact of ageing on T cell pool recovered from gut associated lymphoid tissue (GALT), a crucial site of CD4 T cell accumulation. Primary, secondary and tertiary lymphoid organs of C57BL/6 animals were analysed at three intervals of ages: 2 to 6 months (young), 10 to 14 months (middle-aged) and 22 to 26 months (old). We confirmed that ageing preferentially impacted CD4 T cell compartment in secondary lymphoid organs. Importantly, a different picture emerged from gut associated mucosal sites: during ageing, CD4 T cell accumulation was progressively developing in colon and small intestine lamina propria and Peyer's patches. Similar trend was also observed in middle-aged SJL/B6 F1 mice. Interestingly, an inverse correlation was detected between CD4 T cell numbers in secondary lymphoid organs and colonic lamina propria of C57BL/6 mice whereas no increase in proliferation rate of GALT CD4 T cells was detected. In contrast to GALT, no CD4 T cell accumulation was detected in lungs and liver in middle-aged animals. Finally, the concomitant accumulation of CD4 T cell in GALT and depletion in secondary lymphoid organs during ageing was detected both in male and female animals. Our data thus demonstrate that T cell lymphopenia in secondary lymphoid organs currently associated to ageing is not sustained in gut or lung mucosa associated lymphoid tissues or non-lymphoid sites such as the liver. The inverse correlation between CD4 T cell numbers in secondary lymphoid organs and colonic lamina propria and the absence of overt proliferation in GALT suggest that marked CD4 T cell decay in secondary

  4. Cooperativity of HIV-Specific Cytolytic CD4 T Cells and CD8 T Cells in Control of HIV Viremia

    Science.gov (United States)

    Johnson, Susan; Eller, Michael; Teigler, Jeffrey E.; Maloveste, Sebastien M.; Schultz, Bruce T.; Soghoian, Damien Z.; Lu, Richard; Oster, Alexander F.; Chenine, Agnès-Laurence; Alter, Galit; Dittmer, Ulf; Marovich, Mary; Robb, Merlin L.; Michael, Nelson L.; Bolton, Diane

    2015-01-01

    ABSTRACT CD4+ T cells play a pivotal role in the control of chronic viral infections. Recently, nontraditional CD4+ T cell functions beyond helper effects have been described, and a role for cytolytic CD4+ T cells in the control of HIV infection has been suggested. We define here the transcriptional, phenotypic, and functional profiles of HIV-specific cytolytic CD4+ T cells. Fluidigm BioMark and multiparameter flow cytometric analysis of HIV-specific cytolytic CD4+ T cells revealed a distinct transcriptional signature compared to Th1 CD4+ cells but shared similar features with HIV-specific cytolytic CD8+ T cells. Furthermore, HIV-specific cytolytic CD4+ T cells showed comparable killing activity relative to HIV-specific CD8+ T cells and worked cooperatively in the elimination of virally infected cells. Interestingly, we found that cytolytic CD4+ T cells emerge early during acute HIV infection and tightly follow acute viral load trajectory. This emergence was associated to the early viral set point, suggesting an involvement in early control, in spite of CD4 T cell susceptibility to HIV infection. Our data suggest cytolytic CD4+ T cells as an independent subset distinct from Th1 cells that show combined activity with CD8+ T cells in the long-term control of HIV infection. IMPORTANCE The ability of the immune system to control chronic HIV infection is of critical interest to both vaccine design and therapeutic approaches. Much research has focused on the effect of the ability of CD8+ T cells to control the virus, while CD4+ T cells have been overlooked as effectors in HIV control due to the fact that they are preferentially infected. We show here that a subset of HIV-specific CD4+ T cells cooperate in the cytolytic control of HIV replication. Moreover, these cells represent a distinct subset of CD4+ T cells showing significant transcriptional and phenotypic differences compared to HIV-specific Th1 cells but with similarities to CD8+ T cells. These findings are

  5. TNFα and IFNγ but not perforin are critical for CD8 T cell-mediated protection against pulmonary Yersinia pestis infection.

    Science.gov (United States)

    Szaba, Frank M; Kummer, Lawrence W; Duso, Debra K; Koroleva, Ekaterina P; Tumanov, Alexei V; Cooper, Andrea M; Bliska, James B; Smiley, Stephen T; Lin, Jr-Shiuan

    2014-05-01

    Septic pneumonias resulting from bacterial infections of the lung are a leading cause of human death worldwide. Little is known about the capacity of CD8 T cell-mediated immunity to combat these infections and the types of effector functions that may be most effective. Pneumonic plague is an acutely lethal septic pneumonia caused by the Gram-negative bacterium Yersinia pestis. We recently identified a dominant and protective Y. pestis antigen, YopE69-77, recognized by CD8 T cells in C57BL/6 mice. Here, we use gene-deficient mice, Ab-mediated depletion, cell transfers, and bone marrow chimeric mice to investigate the effector functions of YopE69-77-specific CD8 T cells and their relative contributions during pulmonary Y. pestis infection. We demonstrate that YopE69-77-specific CD8 T cells exhibit perforin-dependent cytotoxicity in vivo; however, perforin is dispensable for YopE69-77-mediated protection. In contrast, YopE69-77-mediated protection is severely impaired when production of TNFα and IFNγ by CD8 T cells is simultaneously ablated. Interestingly, TNFα is absolutely required at the time of challenge infection and can be provided by either T cells or non-T cells, whereas IFNγ provided by T cells prior to challenge appears to facilitate the differentiation of optimally protective CD8 T cells. We conclude that cytokine production, not cytotoxicity, is essential for CD8 T cell-mediated control of pulmonary Y. pestis infection and we suggest that assays detecting Ag-specific TNFα production in addition to antibody titers may be useful correlates of vaccine efficacy against plague and other acutely lethal septic bacterial pneumonias.

  6. CD4+CD25+ regulatory T cells control CD8+ T-cell effector differentiation by modulating IL-2 homeostasis

    Science.gov (United States)

    McNally, Alice; Hill, Geoffrey R.; Sparwasser, Tim; Thomas, Ranjeny; Steptoe, Raymond J.

    2011-01-01

    CD4+CD25+ regulatory T cells (Treg) play a crucial role in the regulation of immune responses. Although many mechanisms of Treg suppression in vitro have been described, the mechanisms by which Treg modulate CD8+ T cell differentiation and effector function in vivo are more poorly defined. It has been proposed, in many instances, that modulation of cytokine homeostasis could be an important mechanism by which Treg regulate adaptive immunity; however, direct experimental evidence is sparse. Here we demonstrate that CD4+CD25+ Treg, by critically regulating IL-2 homeostasis, modulate CD8+ T-cell effector differentiation. Expansion and effector differentiation of CD8+ T cells is promoted by autocrine IL-2 but, by competing for IL-2, Treg limit CD8+ effector differentiation. Furthermore, a regulatory loop exists between Treg and CD8+ effector T cells, where IL-2 produced during CD8+ T-cell effector differentiation promotes Treg expansion. PMID:21502514

  7. CD 4 + CD 25 + T cells maintain homeostasis by promoting TER - 119 cell development and inhibiting T cell activation

    Directory of Open Access Journals (Sweden)

    Muhaimin Rifa’i

    2014-05-01

    Full Text Available CD4+ CD25+ regulatory T cells involved in the regulation of self- tolerance and normality of homeostasis. CD122 deficient mice are model animals that have an abnormal immune system characteristically have a high number of activated T cells and TER-119 cell decreased. Here we showed evidence that the transfer of CD4+ CD25+ regulatory T cells derived from normal mice to CD122- defficient neonates prevent the development of activated memory T cells and elicit TER-119 differentiation. Bone marrow reconstitution derived from CD122-/- mice to normal mice resulting tolerance to individual that genetically different. Importantly, CD4+ CD25+ regulatory T cells derived from normal mice can replace CD4+ CD25+ cells derived from CD122-/- mice. The results of this experiment suggest that regulatory T cells from normal mice exert a critical role in maintaining peripheral tolerance and controlling hematopoietic disorder.

  8. Nonmalignant T cells stimulate growth of T-cell lymphoma cells in the presence of bacterial toxins

    DEFF Research Database (Denmark)

    Woetmann, Anders; Lovato, Paola; Eriksen, Karsten W

    2007-01-01

    Bacterial toxins including staphylococcal enterotoxins (SEs) have been implicated in the pathogenesis of cutaneous T-cell lymphomas (CTCLs). Here, we investigate SE-mediated interactions between nonmalignant T cells and malignant T-cell lines established from skin and blood of CTCL patients....... The malignant CTCL cells express MHC class II molecules that are high-affinity receptors for SE. Although treatment with SE has no direct effect on the growth of the malignant CTCL cells, the SE-treated CTCL cells induce vigorous proliferation of the SE-responsive nonmalignant T cells. In turn, the nonmalignant...... T cells enhance proliferation of the malignant cells in an SE- and MHC class II-dependent manner. Furthermore, SE and, in addition, alloantigen presentation by malignant CTCL cells to irradiated nonmalignant CD4(+) T-cell lines also enhance proliferation of the malignant cells. The growth...

  9. Gut-homing CD4+ T cell receptor alpha beta+ T cells in the pathogenesis of murine inflammatory bowel disease

    DEFF Research Database (Denmark)

    Rudolphi, A; Boll, G; Poulsen, S S

    1994-01-01

    reconstituted a CD3+ T cell receptor alpha beta+ CD4+ T cell subset. CD4+ cells of this subset expressed the surface phenotype of mucosa-seeking, memory T cells. In the immunodeficient scid host, this gut-derived CD4+ T cell subset was found in spleen, peritoneal cavity, mesenteric lymph nodes (LN), epithelial...... compartments with CD4+ T cells from normal GALT plays an essential role in the pathogenesis of IBD in an immunodeficient host.......We studied which T cell subsets from the gut-associated lymphoid tissue (GALT) can migrate out of the gut mucosa and repopulate GALT compartments of an immunodeficient (semi)syngeneic host. Many distinct lymphocyte subsets were found in GALT of immunocompetent H-2d (BALB/c, BALB/cdm2, C.B-17...

  10. Conservation of HIV-1 T cell epitopes across time and clades

    DEFF Research Database (Denmark)

    Levitz, Lauren; Koita, Ousmane A; Sangare, Kotou

    2012-01-01

    HIV genomic sequence variability has complicated efforts to generate an effective globally relevant vaccine. Regions of the viral genome conserved in sequence and across time may represent the "Achilles' heel" of HIV. In this study, highly conserved T-cell epitopes were selected using immunoinfor...

  11. The association between Neovascular Age-related Macular Degeneration and Regulatory T cells in peripheral blood

    DEFF Research Database (Denmark)

    Madelung, Christopher Fugl; Falk, Mads; Sørensen, Torben Lykke

    2015-01-01

    PURPOSE: To investigate regulatory T cells (Tregs) and subsets of the Treg population in patients with neovascular age-related macular degeneration (AMD). PATIENTS AND METHODS: Twenty-one neovascular AMD cases and 12 age-matched controls without retinal pathology were selected. Patients were...

  12. Hypomethylation of the Treg-Specific Demethylated Region in FOXP3 Is a Hallmark of the Regulatory T-cell Subtype in Adult T-cell Leukemia.

    Science.gov (United States)

    Shimazu, Yayoi; Shimazu, Yutaka; Hishizawa, Masakatsu; Hamaguchi, Masahide; Nagai, Yuya; Sugino, Noriko; Fujii, Sumie; Kawahara, Masahiro; Kadowaki, Norimitsu; Nishikawa, Hiroyoshi; Sakaguchi, Shimon; Takaori-Kondo, Akifumi

    2016-02-01

    Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1. Because of its immunosuppressive property and resistance to treatment, patients with ATL have poor prognoses. ATL cells possess the regulatory T cell (Treg) phenotype, such as CD4 and CD25, and usually express forkhead box P3 (FOXP3). However, the mechanisms of FOXP3 expression and its association with Treg-like characteristics in ATL remain unclear. Selective demethylation of the Treg-specific demethylated region (TSDR) in the FOXP3 gene leads to stable FOXP3 expression and defines natural Tregs. Here, we focus on the functional and clinical relationship between the epigenetic pattern of the TSDR and ATL. Analysis of DNA methylation in specimens from 26 patients with ATL showed that 15 patients (58%) hypomethylated the TSDR. The FOXP3(+) cells were mainly observed in the TSDR-hypomethylated cases. The TSDR-hypomethylated ATL cells exerted more suppressive function than the TSDR-methylated ATL cells. Thus, the epigenetic analysis of the FOXP3 gene identified a distinct subtype with Treg properties in heterogeneous ATL. Furthermore, we observed that the hypomethylation of TSDR was associated with poor outcomes in ATL. These results suggest that the DNA methylation status of the TSDR is an important hallmark to define this heterogeneous disease and to predict ATL patient prognosis. ©2015 American Association for Cancer Research.

  13. T-cell recognition is shaped by epitope sequence conservation in the host proteome and microbiome

    DEFF Research Database (Denmark)

    Bresciani, Anne Gøther; Paul, Sinu; Schommer, Nina

    2016-01-01

    or allergen with the conservation of its sequence in the human proteome or the healthy human microbiome. Indeed, performing such comparisons on large sets of validated T-cell epitopes, we found that epitopes that are similar with self-antigens above a certain threshold showed lower immunogenicity, presumably...... as a result of negative selection of T cells capable of recognizing such peptides. Moreover, we also found a reduced level of immune recognition for epitopes conserved in the commensal microbiome, presumably as a result of peripheral tolerance. These findings indicate that the existence (and potentially...

  14. The role of gamma delta T cells in haematopoietic stem cell transplantation

    DEFF Research Database (Denmark)

    Minculescu, L; Sengeløv, H

    2015-01-01

    transplantation modalities increasingly focuses on selective cell depletion and graft engineering with the aim of retaining beneficial immune donor cells for the graft-versus-leukaemia (GVL) effect. In this context, the adoptive and especially innate effector functions of γδ T cells together with clinical studies...... recognition independent from the major histocompatibility complex (MHC) allows for the theoretical possibility of mediating GVL without an allogeneic response in terms of GVHD. Early studies on the impact of γδ T cells in HSCT have reported conflicting results. Recent studies, however, do suggest an overall...

  15. Catch me if you can: Leukemia Escape after CD19-Directed T Cell Immunotherapies

    Directory of Open Access Journals (Sweden)

    Marco Ruella

    2016-01-01

    Full Text Available Immunotherapy is the revolution in cancer treatment of this last decade. Among multiple approaches able to harness the power of the immune system against cancer, T cell based immunotherapies represent one of the most successful examples. In particular, biotechnological engineering of protein structures, like the T cell receptor or the immunoglobulins, allowed the generation of synthetic peptides like chimeric antigen receptors and bispecific antibodies that are able to redirect non-tumor specific T cells to recognize and kill leukemic cells. The anti-CD19/CD3 bispecific antibody blinatumomab and anti-CD19 chimeric antigen receptor T cells (CART19 have produced deep responses in patients with relapsed and refractory B-cell acute leukemias. However, although the majority of these patients responds to anti-CD19 immunotherapy, a subset of them still relapses. Interestingly, a novel family of leukemia escape mechanisms has been described, all characterized by the apparent loss of CD19 on the surface of leukemic blasts. This extraordinary finding demonstrates the potent selective pressure of CART19/blinatumomab that drives extreme and specific escape strategies by leukemic blasts. Patients with CD19-negative relapsed leukemia have very poor prognosis and novel approaches to treat and ideally prevent antigen-loss are direly needed. In this review we discuss the incidence, mechanisms and therapeutic approaches for CD19-negative leukemia relapses occuring after CD19-directed T cell immunotherapies and present our future perspective.

  16. Preferential killing of cancer cells and activated human T cells using ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Cory; Layne, Janet; Feris, Kevin; Wingett, Denise [Department of Biological Sciences, Boise State University, Boise, ID 83725 (United States); Punnoose, Alex; Reddy, K M; Coombs, Isaac; Coombs, Andrew [Department of Physics, Boise State University, Boise, ID 83725 (United States)], E-mail: denisewingett@boisestate.edu

    2008-07-23

    Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signaling environments and compare it to the response of cancerous cells. ZnO nanoparticles exhibit a strong preferential ability to kill cancerous T cells ({approx}28-35 x) compared to normal cells. Interestingly, the activation state of the cell contributes toward nanoparticle toxicity, as resting T cells display a relative resistance while cells stimulated through the T cell receptor and CD28 costimulatory pathway show greater toxicity in direct relation to the level of activation. Mechanisms of toxicity appear to involve the generation of reactive oxygen species, with cancerous T cells producing higher inducible levels than normal T cells. In addition, nanoparticles were found to induce apoptosis and the inhibition of reactive oxygen species was found to be protective against nanoparticle induced cell death. The novel findings of cell selective toxicity, towards potential disease causing cells, indicate a potential utility of ZnO nanoparticles in the treatment of cancer and/or autoimmunity.

  17. Preferential killing of cancer cells and activated human T cells using ZnO nanoparticles

    International Nuclear Information System (INIS)

    Hanley, Cory; Layne, Janet; Feris, Kevin; Wingett, Denise; Punnoose, Alex; Reddy, K M; Coombs, Isaac; Coombs, Andrew

    2008-01-01

    Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signaling environments and compare it to the response of cancerous cells. ZnO nanoparticles exhibit a strong preferential ability to kill cancerous T cells (∼28-35 x) compared to normal cells. Interestingly, the activation state of the cell contributes toward nanoparticle toxicity, as resting T cells display a relative resistance while cells stimulated through the T cell receptor and CD28 costimulatory pathway show greater toxicity in direct relation to the level of activation. Mechanisms of toxicity appear to involve the generation of reactive oxygen species, with cancerous T cells producing higher inducible levels than normal T cells. In addition, nanoparticles were found to induce apoptosis and the inhibition of reactive oxygen species was found to be protective against nanoparticle induced cell death. The novel findings of cell selective toxicity, towards potential disease causing cells, indicate a potential utility of ZnO nanoparticles in the treatment of cancer and/or autoimmunity

  18. CD27 instructs CD4+ T cells to provide help for the memory CD8+ T cell response after protein immunization

    NARCIS (Netherlands)

    Xiao, Yanling; Peperzak, Victor; Keller, Anna M.; Borst, Jannie

    2008-01-01

    For optimal quality, memory CD8(+) T cells require CD4(+) T cell help. We have examined whether CD4(+) T cells require CD27 to deliver this help, in a model of intranasal OVA protein immunization. CD27 deficiency reduced the capacity of CD4(+) T cells to support Ag-specific CD8(+) T cell

  19. Gap junctions at the dendritic cell-T cell interface are key elements for antigen-dependent T cell activation.

    Science.gov (United States)

    Elgueta, Raul; Tobar, Jaime A; Shoji, Kenji F; De Calisto, Jaime; Kalergis, Alexis M; Bono, Maria R; Rosemblatt, Mario; Sáez, Juan C

    2009-07-01

    The acquired immune response begins with Ag presentation by dendritic cells (DCs) to naive T cells in a heterocellular cell-cell contact-dependent process. Although both DCs and T cells are known to express connexin43, a gap junction protein subunit, the role of connexin43 on the initiation of T cell responses remains to be elucidated. In the present work, we report the formation of gap junctions between DCs and T cells and their role on T cell activation during Ag presentation by DCs. In cocultures of DCs and T cells, Lucifer yellow microinjected into DCs is transferred to adjacent transgenic CD4(+) T cells, only if the specific antigenic peptide was present at least during the first 24 h of cocultures. This dye transfer was sensitive to gap junction blockers, such as oleamide, and small peptides containing the extracellular loop sequences of conexin. Furthermore, in this system, gap junction blockers drastically reduced T cell activation as reflected by lower proliferation, CD69 expression, and IL-2 secretion. This lower T cell activation produced by gap junction blockers was not due to a lower expression of CD80, CD86, CD40, and MHC-II on DCs. Furthermore, gap junction blocker did not affect polyclonal activation of T cell induced with anti-CD3 plus anti-CD28 Abs in the absence of DCs. These results strongly suggest that functional gap junctions assemble at the interface between DCs and T cells during Ag presentation and that they play an essential role in T cell activation.

  20. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Keiko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute of Life Sciences for the Next Generation of Women Scientists, Fukuoka University, Fukuoka (Japan); Fujimoto, Takahiro [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Okamura, Tadashi [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ogawa, Masahiro [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tanaka, Yoko [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Mototani, Yasumasa; Goto, Motohito [Division of Animal Models, Department of Infectious Diseases, Research Institute, National Center for Global Health and Medicine, Tokyo (Japan); Ota, Takeharu; Matsuzaki, Hiroshi [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Kuroki, Masahide [Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Tsunoda, Toshiyuki [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan); Sasazuki, Takehiko [Institute for Advanced Study, Kyushu University, Fukuoka (Japan); Shirasawa, Senji, E-mail: sshirasa@fukuoka-u.ac.jp [Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka (Japan); Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka (Japan)

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  1. GM-CSF production allows the identification of immunoprevalent antigens recognized by human CD4+ T cells following smallpox vaccination.

    Directory of Open Access Journals (Sweden)

    Valeria Judkowski

    Full Text Available The threat of bioterrorism with smallpox and the broad use of vaccinia vectors for other vaccines have led to the resurgence in the study of vaccinia immunological memory. The importance of the role of CD4+ T cells in the control of vaccinia infection is well known. However, more CD8+ than CD4+ T cell epitopes recognized by human subjects immunized with vaccinia virus have been reported. This could be, in part, due to the fact that most of the studies that have identified human CD4+ specific protein-derived fragments or peptides have used IFN-γ production to evaluate vaccinia specific T cell responses. Based on these findings, we reasoned that analyzing a large panel of cytokines would permit us to generate a more complete analysis of the CD4 T cell responses. The results presented provide clear evidence that TNF-α is an excellent readout of vaccinia specificity and that other cytokines such as GM-CSF can be used to evaluate the reactivity of CD4+ T cells in response to vaccinia antigens. Furthermore, using these cytokines as readout of vaccinia specificity, we present the identification of novel peptides from immunoprevalent vaccinia proteins recognized by CD4+ T cells derived from smallpox vaccinated human subjects. In conclusion, we describe a "T cell-driven" methodology that can be implemented to determine the specificity of the T cell response upon vaccination or infection. Together, the single pathogen in vitro stimulation, the selection of CD4+ T cells specific to the pathogen by limiting dilution, the evaluation of pathogen specificity by detecting multiple cytokines, and the screening of the clones with synthetic combinatorial libraries, constitutes a novel and valuable approach for the elucidation of human CD4+ T cell specificity in response to large pathogens.

  2. Memory CD8 T cell inflation vs tissue-resident memory T cells: Same patrollers, same controllers?

    Science.gov (United States)

    Welten, Suzanne P M; Sandu, Ioana; Baumann, Nicolas S; Oxenius, Annette

    2018-05-01

    The induction of long-lived populations of memory T cells residing in peripheral tissues is of considerable interest for T cell-based vaccines, as they can execute immediate effector functions and thus provide protection in case of pathogen encounter at mucosal and barrier sites. Cytomegalovirus (CMV)-based vaccines support the induction and accumulation of a large population of effector memory CD8 T cells in peripheral tissues, in a process called memory inflation. Tissue-resident memory (T RM ) T cells, induced by various infections and vaccination regimens, constitute another subset of memory cells that take long-term residence in peripheral tissues. Both memory T cell subsets have evoked substantial interest in exploitation for vaccine purposes. However, a direct comparison between these two peripheral tissue-localizing memory T cell subsets with respect to their short- and long-term ability to provide protection against heterologous challenge is pending. Here, we discuss communalities and differences between T RM and inflationary CD8 T cells with respect to their development, maintenance, function, and protective capacity. In addition, we discuss differences and similarities between the transcriptional profiles of T RM and inflationary T cells, supporting the notion that they are distinct memory T cell populations. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Switching CAR T cells on and off: a novel modular platform for retargeting of T cells to AML blasts

    International Nuclear Information System (INIS)

    Cartellieri, M; Feldmann, A; Koristka, S; Arndt, C; Loff, S; Ehninger, A; Bonin, M von; Bejestani, E P; Ehninger, G; Bachmann, M P

    2016-01-01

    The adoptive transfer of CD19-specific chimeric antigen receptor engineered T cells (CAR T cells) resulted in encouraging clinical trials in indolent B-cell malignancies. However, they also show the limitations of this fascinating technology: CAR T cells can lead to even life-threatening off-tumor, on-target side effects if CAR T cells crossreact with healthy tissues. Here, we describe a novel modular universal CAR platform technology termed UniCAR that reduces the risk of on-target side effects by a rapid and reversible control of CAR T-cell reactivity. The UniCAR system consists of two components: (1) a CAR for an inert manipulation of T cells and (2) specific targeting modules (TMs) for redirecting UniCAR T cells in an individualized time- and target-dependent manner. UniCAR T cells can be armed against different tumor targets simply by replacement of the respective TM for (1) targeting more than one antigen simultaneously or subsequently to enhance efficacy and (2) reducing the risk for development of antigen-loss tumor variants under treatment. Here we provide ‘proof of concept' for retargeting of UniCAR T cells to CD33- and/or CD123-positive acute myeloid leukemia blasts in vitro and in vivo

  4. The lupus susceptibility gene Pbx1 regulates the balance between follicular helper T cell and regulatory T cell differentiation

    Science.gov (United States)

    Choi, Seung-Chul; Hutchinson, Tarun E.; Titov, Anton A.; Seay, Howard R.; Li, Shiwu; Brusko, Todd M.; Croker, Byron P.; Salek-Ardakani, Shahram; Morel, Laurence

    2016-01-01

    Pbx1 controls chromatin accessibility to a large number of genes and is entirely conserved between mice and humans. The Pbx1-d dominant negative isoform is more frequent in the CD4+ T cells from lupus patients than from healthy controls. Pbx1-d is associated with the production of autoreactive T cells in mice carrying the Sle1a1 lupus susceptibility locus. Transgenic expression of Pbx1-d in CD4+ T cells reproduced the phenotypes of Sle1a1 mice, with increased inflammatory functions of CD4+ T cells and impaired regulatory T cell homeostasis. Pbx1-d Tg also expanded the number of follicular helper T cells in a cell-intrinsic and antigen-specific manner that was enhanced in recall responses, and resulted in TH1-biased antibodies. Moreover, Pbx1-d Tg CD4+ T cells upregulated the expression of miR-10a, miR-21 and miR-155, which have been implicated in Treg and TFH cell homeostasis. Our results suggest that Pbx1-d impacts lupus development by regulating effector T cell differentiation and promoting TFH cells at the expense of Treg cells. In addition, our results identify Pbx1 as a novel regulator of CD4+ T cell effector function. PMID:27296664

  5. T-cell libraries allow simple parallel generation of multiple peptide-specific human T-cell clones.

    Science.gov (United States)

    Theaker, Sarah M; Rius, Cristina; Greenshields-Watson, Alexander; Lloyd, Angharad; Trimby, Andrew; Fuller, Anna; Miles, John J; Cole, David K; Peakman, Mark; Sewell, Andrew K; Dolton, Garry

    2016-03-01

    Isolation of peptide-specific T-cell clones is highly desirable for determining the role of T-cells in human disease, as well as for the development of therapies and diagnostics. However, generation of monoclonal T-cells with the required specificity is challenging and time-consuming. Here we describe a library-based strategy for the simple parallel detection and isolation of multiple peptide-specific human T-cell clones from CD8(+) or CD4(+) polyclonal T-cell populations. T-cells were first amplified by CD3/CD28 microbeads in a 96U-well library format, prior to screening for desired peptide recognition. T-cells from peptide-reactive wells were then subjected to cytokine-mediated enrichment followed by single-cell cloning, with the entire process from sample to validated clone taking as little as 6 weeks. Overall, T-cell libraries represent an efficient and relatively rapid tool for the generation of peptide-specific T-cell clones, with applications shown here in infectious disease (Epstein-Barr virus, influenza A, and Ebola virus), autoimmunity (type 1 diabetes) and cancer. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. The effect of conditional EFNB1 deletion in the T cell compartment on T cell development and function

    Directory of Open Access Journals (Sweden)

    Jin Wei

    2011-12-01

    Full Text Available Abstract Background Eph kinases are the largest family of cell surface receptor tyrosine kinases. The ligands of Ephs, ephrins (EFNs, are also cell surface molecules. Ephs interact with EFNs transmitting signals in both directions, i.e., from Ephs to EFNs and from EFNs to Ephs. EFNB1 is known to be able to co-stimulate T cells in vitro and to modulate thymocyte development in a model of foetal thymus organ culture. To further understand the role of EFNB1 in T cell immunity, we generated T-cell-specific EFNB1 gene knockout mice to assess T cell development and function in these mice. Results The mice were of normal size and cellularity in the thymus and spleen and had normal T cell subpopulations in these organs. The bone marrow progenitors from KO mice and WT control mice repopulated host spleen T cell pool to similar extents. The activation and proliferation of KO T cells was comparable to that of control mice. Naïve KO CD4 cells showed an ability to differentiate into Th1, Th2, Th17 and Treg cells similar to control CD4 cells. Conclusions Our results suggest that the function of EFNB1 in the T cell compartment could be compensated by other members of the EFN family, and that such redundancy safeguards the pivotal roles of EFNB1 in T cell development and function.

  7. Cryoballoon Ablation for Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Jason G. Andrade, MD

    2012-03-01

    Full Text Available Focal point-by-point radiofrequency catheter ablation has shown considerable success in the treatment of paroxysmal atrial fibrillation. However, it is not without limitations. Recent clinical and preclinical studies have demonstrated that cryothermal ablation using a balloon catheter (Artic Front©, Medtronic CryoCath LP provides an effective alternative strategy to treating atrial fibrillation. The objective of this article is to review efficacy and safety data surrounding cryoballoon ablation for paroxysmal and persistent atrial fibrillation. In addition, a practical step-by-step approach to cryoballoon ablation is presented, while highlighting relevant literature regarding: 1 the rationale for adjunctive imaging, 2 selection of an appropriate cryoballoon size, 3 predictors of efficacy, 4 advanced trouble-shooting techniques, and 5 strategies to reduce procedural complications, such as phrenic nerve palsy.

  8. miRNA profiling of naive, effector and memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Haoquan Wu

    Full Text Available microRNAs have recently emerged as master regulators of gene expression during development and cell differentiation. Although profound changes in gene expression also occur during antigen-induced T cell differentiation, the role of miRNAs in the process is not known. We compared the miRNA expression profiles between antigen-specific naïve, effector and memory CD8+ T cells using 3 different methods--small RNA cloning, miRNA microarray analysis and real-time PCR. Although many miRNAs were expressed in all the T cell subsets, the frequency of 7 miRNAs (miR-16, miR-21, miR-142-3p, miR-142-5p, miR-150, miR-15b and let-7f alone accounted for approximately 60% of all miRNAs, and their expression was several fold higher than the other expressed miRNAs. Global downregulation of miRNAs (including 6/7 dominantly expressed miRNAs was observed in effector T cells compared to naïve cells and the miRNA expression levels tended to come back up in memory T cells. However, a few miRNAs, notably miR-21 were higher in effector and memory T cells compared to naïve T cells. These results suggest that concomitant with profound changes in gene expression, miRNA profile also changes dynamically during T cell differentiation. Sequence analysis of the cloned mature miRNAs revealed an extensive degree of end polymorphism. While 3'end polymorphisms dominated, heterogeneity at both ends, resembling drosha/dicer processing shift was also seen in miR-142, suggesting a possible novel mechanism to generate new miRNA and/or to diversify miRNA target selection. Overall, our results suggest that dynamic changes in the expression of miRNAs may be important for the regulation of gene expression during antigen-induced T cell differentiation. Our study also suggests possible novel mechanisms for miRNA biogenesis and function.

  9. High epitope expression levels increase competition between T cells.

    Directory of Open Access Journals (Sweden)

    Almut Scherer

    2006-08-01

    Full Text Available Both theoretical predictions and experimental findings suggest that T cell populations can compete with each other. There is some debate on whether T cells compete for aspecific stimuli, such as access to the surface on antigen-presenting cells (APCs or for specific stimuli, such as their cognate epitope ligand. We have developed an individual-based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell competition is mainly for specific or aspecific stimuli. Under low epitope expression, competition is mainly for the specific epitope stimuli, and, hence, different epitope-specific T cell populations coexist readily. However, if epitope expression levels are high, aspecific competition becomes more important. Such between-specificity competition can lead to competitive exclusion between different epitope-specific T cell populations. Our model allows us to delineate the circumstances that facilitate coexistence of T cells of different epitope specificity. Understanding mechanisms of T cell coexistence has important practical implications for immune therapies that require a broad immune response.

  10. Genomewide analyses of pathogenic and regulatory T cells of NOD ...

    Indian Academy of Sciences (India)

    DANG SUN

    1School of Life Sciences, Tsinghua University, Qinghuayuan Road, Beijing 100084, People's Republic of China. 2Alliance ... Reestablishing a well-balanced population of regulatory T cells (Tregs) .... Definition of CpG methylation peaks: Log2 ratios between ..... How these eight genes work in T cell function differentiation.

  11. Determining T-cell specificity to understand and treat disease

    DEFF Research Database (Denmark)

    Hadrup, Sine Reker; Newell, Evan W.

    2017-01-01

    Adaptive immune responses and immunopathogeneses are based on the ability of T cells to respond to specific antigens. Consequently, understanding T-cell recognition patterns in health and disease involves studying the complexity and genetic heterogeneity of the antigen recognition pathway, which...

  12. T Cell Responses: Naive to Memory and Everything in Between

    Science.gov (United States)

    Pennock, Nathan D.; White, Jason T.; Cross, Eric W.; Cheney, Elizabeth E.; Tamburini, Beth A.; Kedl, Ross M.

    2013-01-01

    The authors describe the actions that take place in T cells because of their amazing capacity to proliferate and adopt functional roles aimed at clearing a host of an infectious agent. There is a drastic decline in the T cell population once the primary response is over and the infection is terminated. What remains afterward is a population of T…

  13. A response calculus for immobilized T cell receptor ligands

    DEFF Research Database (Denmark)

    Andersen, P S; Menné, C; Mariuzza, R A

    2001-01-01

    determine the level of T cell activation. When fitted to T cell responses against purified ligands immobilized on plastic surfaces, the 2D-affinity model adequately simulated changes in cellular activation as a result of varying ligand affinity and ligand density. These observations further demonstrated...

  14. Regulatory T Cells: Potential Target in Anticancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Chi-Mou Juang

    2007-09-01

    Full Text Available The concept of regulatory T cells was first described in the early 1970s, and regulatory T cells were called suppressive T cells at that time. Studies that followed have demonstrated that these suppressive T cells negatively regulated tumor immunity and contributed to tumor growth in mice. Despite the importance of these studies, there was extensive skepticism about the existence of these cells, and the concept of suppressive T cells left the center stage of immunologic research for decades. Interleukin-2 receptor α-chain, CD25, was first demonstrated in 1995 to serve as a phenotypic marker for CD4+ regulatory cells. Henceforth, research of regulatory T cells boomed. Regulatory T cells are involved in the pathogenesis of cancer, autoimmune disease, transplantation immunology, and immune tolerance in pregnancy. Recent evidence has demonstrated that regulatory T cellmediated immunosuppression is one of the crucial tumor immune evasion mechanisms and the main obstacle of successful cancer immunotherapy. The mechanism and the potential clinical application of regulatory T cells in cancer immunotherapy are discussed.

  15. T cell motility as modulator of interactions with dendritic cells

    Directory of Open Access Journals (Sweden)

    Jens Volker Stein

    2015-11-01

    Full Text Available It is well established that the balance of costimulatory and inhibitory signals during interactions with dendritic cells (DCs determines T cell transition from a naïve to an activated or tolerant/anergic status. While many of these molecular interactions are well reproduced in reductionist in vitro assays, the highly dynamic motility of naïve T cells in lymphoid tissue acts as an additional lever to fine-tune their activation threshold. T cell detachment from DCs providing suboptimal stimulation allows them to search for DCs with higher levels of stimulatory signals, while storing a transient memory of short encounters. In turn, adhesion of weakly reactive T cells to DCs presenting pMHC with low affinity is prevented by lipid mediators. Finally, controlled recruitment of CD8+ T cells to cognate DC – CD4+ T cell clusters shapes memory T cell formation and the quality of the immune response. Dynamic physiological lymphocyte motility therefore constitutes a mechanism to mitigate low avidity T cell activation and to improve the search for optimal DCs, while contributing to peripheral tolerance induction in the absence of inflammation.

  16. Prospects and limitations of T cell receptor gene therapy

    NARCIS (Netherlands)

    Jorritsma, Annelies; Schotte, Remko; Coccoris, Miriam; de Witte, Moniek A.; Schumacher, Ton N. M.

    2011-01-01

    Adoptive transfer of antigen-specific T cells is an attractive means to provide cancer patients with immune cells of a desired specificity and the efficacy of such adoptive transfers has been demonstrated in several clinical trials. Because the T cell receptor is the single specificity-determining

  17. Genomewide analyses of pathogenic and regulatory T cells of NOD ...

    Indian Academy of Sciences (India)

    Reestablishing a well-balanced population of regulatory T cells (Tregs) and pathogenic T cells (Tpaths) is necessary for diabetic patients to regain glucose control. However, the molecular mechanisms modulating functional differentiation of Tpaths and Tregs remain unclear. In this study, we anal- ysed the gene expression ...

  18. T-cell mediated immunity in Wegener's granulomatosis

    NARCIS (Netherlands)

    Abdulahad, Wayel Habib

    2008-01-01

    Although the pathogenetic mechanisms involved in Wegener’s granulomatosis (WG) are not completely understood, considerable evidence support the concepts that activated T-cells play an important role in disease expression. It is, however, not clear which subsets of T-cells are involved in the

  19. Dissection and manipulation of antigen-specific T cell responses

    NARCIS (Netherlands)

    Schepers, Koen

    2006-01-01

    T cells recognize pathogen-derived antigens and are crucial for fighting pathogens such as viruses and bacteria. In addition, T cells are able to recognize and attack certain types of tumors, in particular virally induced tumors. In this thesis we aimed 1) to obtain more insight into

  20. Roles of T Cells in the Pathogenesis of Autoimmune Diseases

    Directory of Open Access Journals (Sweden)

    Dinglei Su

    2013-01-01

    Full Text Available γδ T cells are a minor population of T cells that express the TCR γδ chains, mainly distributed in the mucosal and epithelial tissue and accounting for less than 5% of the total T cells in the peripheral blood. By bridging innate and adaptive immunity, γδ T cells play important roles in the anti-infection, antitumor, and autoimmune responses. Previous research on γδ T cells was primarily concentrated on infectious diseases and tumors, whereas their functions in autoimmune diseases attracted much attention. In this paper, we summarized the various functions of γδ T cells in two prototypical autoimmune connective tissue diseases, that is, SLE and RA, elaborating on their antigen-presenting capacity, secretion of proinflammatory cytokines, immunomodulatory effects, and auxiliary function for B cells, which contribute to overproduction of proinflammatory cytokines and pathogenic autoantibodies, ultimately leading to the onset of these autoimmune diseases. Elucidation of the roles of γδ T cells in autoimmune diseases is not only conducive to in-depth understanding of the pathogenesis of these diseases, but also beneficial in providing theoretical support for the development of γδ T-cell-targeted therapy.

  1. Cortisol patterns are associated with T cell activation in HIV.

    Directory of Open Access Journals (Sweden)

    Sarah Patterson

    Full Text Available The level of T cell activation in untreated HIV disease is strongly and independently associated with risk of immunologic and clinical progression. The factors that influence the level of activation, however, are not fully defined. Since endogenous glucocorticoids are important in regulating inflammation, we sought to determine whether less optimal diurnal cortisol patterns are associated with greater T cell activation.We studied 128 HIV-infected adults who were not on treatment and had a CD4(+ T cell count above 250 cells/µl. We assessed T cell activation by CD38 expression using flow cytometry, and diurnal cortisol was assessed with salivary measurements.Lower waking cortisol levels correlated with greater T cell immune activation, measured by CD38 mean fluorescent intensity, on CD4(+ T cells (r = -0.26, p = 0.006. Participants with lower waking cortisol also showed a trend toward greater activation on CD8(+ T cells (r = -0.17, p = 0.08. A greater diurnal decline in cortisol, usually considered a healthy pattern, correlated with less CD4(+ (r = 0.24, p = 0.018 and CD8(+ (r = 0.24, p = 0.017 activation.These data suggest that the hypothalamic-pituitary-adrenal (HPA axis contributes to the regulation of T cell activation in HIV. This may represent an important pathway through which psychological states and the HPA axis influence progression of HIV.

  2. Structural elements recognized by abacavir-induced T cells

    DEFF Research Database (Denmark)

    Yerly, Daniel; Pompeu, Yuri Andreiw; Schutte, Ryan J.

    2017-01-01

    of autoimmune destruction. The structural elements recognized by drug-specific T cell receptors (TCRs) in vivo are poorly defined. Drug-stimulated T cells express TCRs specific for peptide/HLA complexes, but the characteristics of peptides (sequence, or endogenous or exogenous origin) presented in the context...

  3. T-cell receptor Vβ skewing frequently occurs in refractory cytopenia of childhood and is associated with an expansion of effector cytotoxic T cells: a prospective study by EWOG-MDS

    International Nuclear Information System (INIS)

    Aalbers, A M; Heuvel-Eibrink, M M van den; Baumann, I; Beverloo, H B; Driessen, G J; Dworzak, M; Fischer, A; Göhring, G; Hasle, H; Locatelli, F; De Moerloose, B; Noellke, P; Schmugge, M; Stary, J; Yoshimi, A; Zecca, M; Zwaan, C M; Dongen, J J M van; Pieters, R; Niemeyer, C M; Velden, V H J van der; Langerak, A W

    2014-01-01

    Immunosuppressive therapy (IST), consisting of antithymocyte globulin and cyclosporine A, is effective in refractory cytopenia of childhood (RCC), suggesting that, similar to low-grade myelodysplastic syndromes in adult patients, T lymphocytes are involved in suppressing hematopoiesis in a subset of RCC patients. However, the potential role of a T-cell-mediated pathophysiology in RCC remains poorly explored. In a cohort of 92 RCC patients, we prospectively assessed the frequency of T-cell receptor (TCR) β-chain variable (Vβ) domain skewing in bone marrow and peripheral blood by heteroduplex PCR, and analyzed T-cell subsets in peripheral blood by flow cytometry. TCRVβ skewing was present in 40% of RCC patients. TCRVβ skewing did not correlate with bone marrow cellularity, karyotype, transfusion history, HLA-DR15 or the presence of a PNH clone. In 28 patients treated with IST, TCRVβ skewing was not clearly related with treatment response. However, TCRVβ skewing did correlate with a disturbed CD4 + /CD8 + T-cell ratio, a reduction in naive CD8 + T cells, an expansion of effector CD8 + T cells and an increase in activated CD8 + T cells (defined as HLA-DR + , CD57 + or CD56 + ). These data suggest that T lymphocytes contribute to RCC pathogenesis in a proportion of patients, and provide a rationale for treatment with IST in selected patients with RCC

  4. T cell receptor sequencing of early-stage breast cancer tumors identifies altered clonal structure of the T cell repertoire.

    Science.gov (United States)

    Beausang, John F; Wheeler, Amanda J; Chan, Natalie H; Hanft, Violet R; Dirbas, Frederick M; Jeffrey, Stefanie S; Quake, Stephen R

    2017-11-28

    Tumor-infiltrating T cells play an important role in many cancers, and can improve prognosis and yield therapeutic targets. We characterized T cells infiltrating both breast cancer tumors and the surrounding normal breast tissue to identify T cells specific to each, as well as their abundance in peripheral blood. Using immune profiling of the T cell beta-chain repertoire in 16 patients with early-stage breast cancer, we show that the clonal structure of the tumor is significantly different from adjacent breast tissue, with the tumor containing ∼2.5-fold greater density of T cells and higher clonality compared with normal breast. The clonal structure of T cells in blood and normal breast is more similar than between blood and tumor, and could be used to distinguish tumor from normal breast tissue in 14 of 16 patients. Many T cell sequences overlap between tissue and blood from the same patient, including ∼50% of T cells between tumor and normal breast. Both tumor and normal breast contain high-abundance "enriched" sequences that are absent or of low abundance in the other tissue. Many of these T cells are either not detected or detected with very low frequency in the blood, suggesting the existence of separate compartments of T cells in both tumor and normal breast. Enriched T cell sequences are typically unique to each patient, but a subset is shared between many different patients. We show that many of these are commonly generated sequences, and thus unlikely to play an important role in the tumor microenvironment. Copyright © 2017 the Author(s). Published by PNAS.

  5. Ets transcription factor GABP controls T cell homeostasis and immunity.

    Science.gov (United States)

    Luo, Chong T; Osmanbeyoglu, Hatice U; Do, Mytrang H; Bivona, Michael R; Toure, Ahmed; Kang, Davina; Xie, Yuchen; Leslie, Christina S; Li, Ming O

    2017-10-20

    Peripheral T cells are maintained in the absence of vigorous stimuli, and respond to antigenic stimulation by initiating cell cycle progression and functional differentiation. Here we show that depletion of the Ets family transcription factor GA-binding protein (GABP) in T cells impairs T-cell homeostasis. In addition, GABP is critically required for antigen-stimulated T-cell responses in vitro and in vivo. Transcriptome and genome-wide GABP-binding site analyses identify GABP direct targets encoding proteins involved in cellular redox balance and DNA replication, including the Mcm replicative helicases. These findings show that GABP has a nonredundant role in the control of T-cell homeostasis and immunity.

  6. Engineering Therapeutic T Cells: From Synthetic Biology to Clinical Trials.

    Science.gov (United States)

    Esensten, Jonathan H; Bluestone, Jeffrey A; Lim, Wendell A

    2017-01-24

    Engineered T cells are currently in clinical trials to treat patients with cancer, solid organ transplants, and autoimmune diseases. However, the field is still in its infancy. The design, and manufacturing, of T cell therapies is not standardized and is performed mostly in academic settings by competing groups. Reliable methods to define dose and pharmacokinetics of T cell therapies need to be developed. As of mid-2016, there are no US Food and Drug Administration (FDA)-approved T cell therapeutics on the market, and FDA regulations are only slowly adapting to the new technologies. Further development of engineered T cell therapies requires advances in immunology, synthetic biology, manufacturing processes, and government regulation. In this review, we outline some of these challenges and discuss the contributions that pathologists can make to this emerging field.

  7. PD-1 Blockade Expands Intratumoral Memory T Cells

    DEFF Research Database (Denmark)

    Ribas, Antoni; Shin, Daniel Sanghoon; Zaretsky, Jesse

    2016-01-01

    by multicolor flow cytometry using two computational approaches to resolve the leukocyte phenotypes at the single-cell level. There was a statistically significant increase in the frequency of T cells in patients who responded to therapy. The frequency of intratumoral B cells and monocytic myeloid......-derived suppressor cells significantly increased in patients' biopsies taken on treatment. The percentage of cells with a regulatory T-cell phenotype, monocytes, and natural killer cells did not change while on PD-1 blockade therapy. CD8+ memory T cells were the most prominent phenotype that expanded intratumorally...... on therapy. However, the frequency of CD4+ effector memory T cells significantly decreased on treatment, whereas CD4+ effector T cells significantly increased in nonresponding tumors on therapy. In peripheral blood, an unusual population of blood cells expressing CD56 was detected in two patients...

  8. Parathyroid hormone dependent T cell proliferation in uremic rats

    DEFF Research Database (Denmark)

    Lewin, E; Ladefoged, Jens; Brandi, L

    1993-01-01

    Chronic renal failure (CRF) is combined with an impairment of the immune system. The T cell may be a target for the action of parathyroid hormone (PTH). Rats with CRF have high blood levels of PTH. Therefore, the present investigation examined some aspects of the T cell function in both normal...... and CRF rats before and after parathyroidectomy and after an isogenic kidney transplantation. The T cell proliferative response to phytohemagglutinin (PHA) stimulation was significantly higher in peripheral blood mononuclear cell (PBMC) cultures obtained from CRF rats than from normal rats. After...... parathyroidectomy the T cells of normal as well as of uremic rats could still be significantly stimulated by PHA, but now no significant difference was seen. When CRF was reversed after an isogenic kidney transplantation and PTH reversed to levels in the normal range, the T cell proliferative response to PHA...

  9. Epigenetic control of CD8+ T cell differentiation.

    Science.gov (United States)

    Henning, Amanda N; Roychoudhuri, Rahul; Restifo, Nicholas P

    2018-05-01

    Upon stimulation, small numbers of naive CD8 + T cells proliferate and differentiate into a variety of memory and effector cell types. CD8 + T cells can persist for years and kill tumour cells and virally infected cells. The functional and phenotypic changes that occur during CD8 + T cell differentiation are well characterized, but the epigenetic states that underlie these changes are incompletely understood. Here, we review the epigenetic processes that direct CD8 + T cell differentiation and function. We focus on epigenetic modification of DNA and associated histones at genes and their regulatory elements. We also describe structural changes in chromatin organization that affect gene expression. Finally, we examine the translational potential of epigenetic interventions to improve CD8 + T cell function in individuals with chronic infections and cancer.

  10. Ablative thermal protection systems

    International Nuclear Information System (INIS)

    Vaniman, J.; Fisher, R.; Wojciechowski, C.; Dean, W.

    1983-01-01

    The procedures used to establish the TPS (thermal protection system) design of the SRB (solid rocket booster) element of the Space Shuttle vehicle are discussed. A final evaluation of the adequacy of this design will be made from data obtained from the first five Shuttle flights. Temperature sensors installed at selected locations on the SRB structure covered by the TPS give information as a function of time throughout the flight. Anomalies are to be investigated and computer design thermal models adjusted if required. In addition, the actual TPS ablator material loss is to be measured after each flight and compared with analytically determined losses. The analytical methods of predicting ablator performance are surveyed. 5 references

  11. CD4~+Foxp3~+ regulatory T cells converted by rapamycin from peripheral CD4~+ CD25~-naive T cells display more potent regulatory ability in vitro

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-fei; GAO Jie; ZHANG Dong; WANG Zi-han; ZHU Ji-ye

    2010-01-01

    Background Rapamycin (RAPA) is a relatively new immunosuppressant drug that functions as a serine/threonine kinase inhibitor to prevent rejection in organ transplantation. RAPA blocks activation of T-effector (Teff) cells by inhibiting the response to interleukin-2. Recently, RAPA was also shown to selectively expand the T-regulator (Treg) cell population. To date, no studies have examined the mechanism by which RAPA converts Teff cells to Treg cells. Methods Peripheral CD4~+CD25~- naive T cells were cultivated with RAPA and B cells as antigen-presenting cells (APCs) in vitro. CD4~+CD25~- T cells were harvested after 6 days and analyzed for expression of forkhead box protein 3 (Foxp3) using flow cytometry. CD4~+CD25~+CD127~- subsets as the converted Tregs were isolated from the mixed lymphocyte reactions (MLR) with CD127 negative selection, followed by CD4 and CD25 positive selection using microbeads and magnetic separation column (MSC). Moreover, mRNA was extracted from converted Tregs and C57BL/6 naive CD4~+CD25~+ T cells and Foxp3 levels were examined by quantitative real-time polymerase chain reaction (rt-PCR). A total of 1×10~5 carboxyfluorescein succinimidyl ester (CFSE)-labeled naive CD4~+CD25~- T cells/well from C57BL/6 mice were cocultured with DBA/2 or C3H maturation of dendritic cells (mDCs) (0.25×10~5/well) in 96-well round-bottom plates for 6 days. Then 1×10~5 or 0.25×10~5 converted Treg cells were added to every well as regulatory cells. Cells were harvested after 6 days of culture and analyzed for proliferation of CFSE-labeled naive CD4~+CD25~- T cells using flow cytometry. Data were analyzed using CellQuest software.Results We found that RAPA can convert peripheral CD4~+CD25~- naive T Cells to CD4~+Foxp3~+ Treg cells using B cells as APCs, and this subtype of Treg can potently suppress Teff proliferation and maintain antigenic specificity. Conclusion Our findings provide evidence that RAPA induces Treg cell conversion from Teff cells and

  12. Clinical applications of gamma delta T cells with multivalent immunity

    Directory of Open Access Journals (Sweden)

    Drew C Deniger

    2014-12-01

    Full Text Available Gamma delta T cells hold promise for adoptive immunotherapy because of their reactivity to bacteria, viruses, and tumors. However, these cells represent a small fraction (1-5% of the peripheral T-cell pool and require activation and propagation to achieve clinical benefit. Aminobisphosphonates specifically expand the Vgamma9Vdelta2 subset of gamma delta T cells and have been used in clinical trials of cancer where objective responses were detected. The Vgamma9Vdelta2 TCR heterodimer binds multiple ligands and results in a multivalent attack by a monoclonal T cell population. Alternatively, populations of gamma delta T cells with oligoclonal or polyclonal TCR repertoire could be infused for broad-range specificity. However, this goal has been restricted by a lack of applicable expansion protocols for non-Vgamma9Vdelta2 cells. Recent advances using immobilized antigens, agonistic monoclonal antibodies (mAbs, tumor-derived artificial antigen presenting cells (aAPC, or combinations of activating mAbs and aAPC have been successful in expanding gamma delta T cells with oligoclonal or polyclonal TCR repertoires. Immobilized MHC Class-I chain-related A was a stimulus for gamma delta T cells expressing TCRdelta1 isotypes, and plate-bound activating antibodies have expanded Vdelta1 and Vdelta2 cells ex vivo. Clinically-sufficient quantities of TCRdelta1, TCRdelta2, and TCRdelta1negTCRdelta2neg have been produced following co-culture on aAPC, and these subsets displayed differences in memory phenotype and reactivity to tumors in vitro and in vivo. Gamma delta T cells are also amenable to genetic modification as evidenced by introduction of alpha beta TCRs, chimeric antigen receptors (CARs, and drug-resistance genes. This represents a promising future for the clinical application of oligoclonal or polyclonal gamma delta T cells in autologous and allogeneic settings that builds on current trials testing the safety and efficacy of Vgamma9Vdelta2 T cells.

  13. Radiofrequency Ablation of Lung Tumors

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

  14. T Cell Epitope Immunotherapy Induces a CD4+ T Cell Population with Regulatory Activity

    Directory of Open Access Journals (Sweden)

    Verhoef Adrienne

    2005-01-01

    Full Text Available Background Synthetic peptides, representing CD4+ T cell epitopes, derived from the primary sequence of allergen molecules have been used to down-regulate allergic inflammation in sensitised individuals. Treatment of allergic diseases with peptides may offer substantial advantages over treatment with native allergen molecules because of the reduced potential for cross-linking IgE bound to the surface of mast cells and basophils. Methods and Findings In this study we address the mechanism of action of peptide immunotherapy (PIT in cat-allergic, asthmatic patients. Cell-division-tracking dyes, cell-mixing experiments, surface phenotyping, and cytokine measurements were used to investigate immunomodulation in peripheral blood mononuclear cells (PBMCs after therapy. Proliferative responses of PBMCs to allergen extract were significantly reduced after PIT. This was associated with modified cytokine profiles generally characterised by an increase in interleukin-10 and a decrease in interleukin-5 production. CD4+ cells isolated after PIT were able to actively suppress allergen-specific proliferative responses of pretreatment CD4neg PBMCs in co-culture experiments. PIT was associated with a significant increase in surface expression of CD5 on both CD4+ and CD8+ PBMCs. Conclusion This study provides evidence for the induction of a population of CD4+ T cells with suppressor/regulatory activity following PIT. Furthermore, up-regulation of cell surface levels of CD5 may contribute to reduced reactivity to allergen.

  15. Role of 4-1BB receptor in the control played by CD8(+ T cells on IFN-gamma production by Mycobacterium tuberculosis antigen-specific CD4(+ T Cells.

    Directory of Open Access Journals (Sweden)

    Carla Palma

    Full Text Available BACKGROUND: Antigen-specific IFN-gamma producing CD4(+ T cells are the main mediators of protection against Mycobacterium tuberculosis infection both under natural conditions and following vaccination. However these cells are responsible for lung damage and poor vaccine efficacy when not tightly controlled. Discovering new tools to control nonprotective antigen-specific IFN-gamma production without affecting protective IFN-gamma is a challenge in tuberculosis research. METHODS AND FINDINGS: Immunization with DNA encoding Ag85B, a candidate vaccine antigen of Mycobacterium tuberculosis, elicited in mice a low but protective CD4(+ T cell-mediated IFN-gamma response, while in mice primed with DNA and boosted with Ag85B protein a massive increase in IFN-gamma response was associated with loss of protection. Both protective and non-protective Ag85B-immunization generated antigen-specific CD8(+ T cells which suppressed IFN-gamma-secreting CD4(+ T cells. However, ex vivo ligation of 4-1BB, a member of TNF-receptor super-family, reduced the massive, non-protective IFN-gamma responses by CD4(+ T cells in protein-boosted mice without affecting the low protective IFN-gamma-secretion in mice immunized with DNA. This selective inhibition was due to the induction of 4-1BB exclusively on CD8(+ T cells of DNA-primed and protein-boosted mice following Ag85B protein stimulation. The 4-1BB-mediated IFN-gamma inhibition did not require soluble IL-10, TGF-beta, XCL-1 and MIP-1beta. In vivo Ag85B stimulation induced 4-1BB expression on CD8(+ T cells and in vivo 4-1BB ligation reduced the activation, IFN-gamma production and expansion of Ag85B-specific CD4(+ T cells of DNA-primed and protein-boosted mice. CONCLUSION/SIGNIFICANCE: Antigen-specific suppressor CD8(+ T cells are elicited through immunization with the mycobacterial antigen Ag85B. Ligation of 4-1BB receptor further enhanced their suppressive activity on IFN-gamma-secreting CD4(+ T cells. The selective

  16. Allogeneic CD19-CAR-T cell infusion after allogeneic hematopoietic stem cell transplantation in B cell malignancies.

    Science.gov (United States)

    Liu, Jun; Zhong, Jiang F; Zhang, Xi; Zhang, Cheng

    2017-01-31

    Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered the cornerstone in treatment of hematological malignancies. However, relapse of the hematological disease after allo-HSCT remains a challenge and is associated with poor long-term survival. Chimeric antigen receptor redirected T cells (CAR-T cells) can lead to disease remission in patients with relapsed/refractory hematological malignancies. However, the therapeutic window for infusion of CAR-T cells post allo-HSCT and its efficacy are debatable. In this review, we first discuss the use of CAR-T cells for relapsed cases after allo-HSCT. We then review the toxicities and the occurrence of graft-versus-host disease in relapsed patients who received CAR-T cells post allo-HSCT. Finally, we review clinical trial registrations and the therapeutic time window for infusion of CAR-T cells post allo-HSCT. The treatment of allogeneic CAR-T cells is beneficial for patients with relapsed B cell malignancies after allo-HSCT with low toxicities and complications. However, multicenter clinical trials with larger sample sizes should be performed to select the optimal therapeutic window and confirm its efficacy.

  17. Efficacy and toxicity management of CAR-T-cell immunotherapy: a matter of responsiveness control or tumour-specificity?

    Science.gov (United States)

    Alonso-Camino, Vanesa; Harwood, Seandean Lykke; Álvarez-Méndez, Ana; Alvarez-Vallina, Luis

    2016-04-15

    Chimaeric antigen receptor (CAR)-expressing T-cells have demonstrated potent clinical efficacy in patients with haematological malignancies. However, the use of CAR-T-cells targeting solid tumour-associated antigens (TAAs) has been limited by organ toxicities related to activation of T-cell effector functions through the CAR. Most existing CARs recognize TAAs, which are also found in normal tissues. CAR-T-cell-mediated destruction of normal tissues constitutes a major roadblock to CAR-T-cell therapy, and must be avoided or mitigated. There is a broad range of strategies for modulating antigen responsiveness of CAR-T-cells, with varying degrees of complexity. Some of them might ameliorate the acute and chronic toxicities associated with current CAR constructs. However, further embellishments to CAR therapy may complicate clinical implementation and possibly create new immunogenicity issues. In contrast, the development of CARs targeting truly tumour-specific antigens might circumvent on-target/off-tumour toxicities without adding additional complexity to CAR-T-cell therapies, but these antigens have been elusive and may require novel selection strategies for their discovery. © 2016 Authors; published by Portland Press Limited.

  18. Functional properties of T cells in patients with chronic T gamma lymphocytosis and chronic T cell neoplasia

    NARCIS (Netherlands)

    Rümke, H. C.; Miedema, F.; ten Berge, I. J.; Terpstra, F.; van der Reijden, H. J.; van de Griend, R. J.; de Bruin, H. G.; von dem Borne, A. E.; Smit, J. W.; Zeijlemaker, W. P.; Melief, C. J.

    1982-01-01

    The expanded T cell populations of 10 patients with either T gamma lymphocytosis (five patients) or proven chronic T cell malignancy (five patients) were analyzed with respect to functional activity in vitro, including proliferative responses to mitogens, cytotoxic activity (killer [K] and natural

  19. Suboptimal T-cell receptor signaling compromises protein translation, ribosome biogenesis, and proliferation of mouse CD8 T cells.

    Science.gov (United States)

    Tan, Thomas C J; Knight, John; Sbarrato, Thomas; Dudek, Kate; Willis, Anne E; Zamoyska, Rose

    2017-07-25

    Global transcriptomic and proteomic analyses of T cells have been rich sources of unbiased data for understanding T-cell activation. Lack of full concordance of these datasets has illustrated that important facets of T-cell activation are controlled at the level of translation. We undertook translatome analysis of CD8 T-cell activation, combining polysome profiling and microarray analysis. We revealed that altering T-cell receptor stimulation influenced recruitment of mRNAs to heavy polysomes and translation of subsets of genes. A major pathway that was compromised, when TCR signaling was suboptimal, was linked to ribosome biogenesis, a rate-limiting factor in both cell growth and proliferation. Defective TCR signaling affected transcription and processing of ribosomal RNA precursors, as well as the translation of specific ribosomal proteins and translation factors. Mechanistically, IL-2 production was compromised in weakly stimulated T cells, affecting the abundance of Myc protein, a known regulator of ribosome biogenesis. Consequently, weakly activated T cells showed impaired production of ribosomes and a failure to maintain proliferative capacity after stimulation. We demonstrate that primary T cells respond to various environmental cues by regulating ribosome biogenesis and mRNA translation at multiple levels to sustain proliferation and differentiation.

  20. Delineation of canine parvovirus T cell epitopes with peripheral blood mononuclear cells and T cell clones from immunized dogs.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); M.C.M. Poelen (Martien); R.H. Meloen; J. Carlson; F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1990-01-01

    textabstractThree synthetic peptides derived from the amino acid sequence of VP2 of canine parvovirus (CPV) which were recently shown to represent three distinct T cell epitopes for BALB/c mice could prime BALB/c mice for a CPV-specific proliferative T cell response upon immunization. Proliferative

  1. T cell epitopes on the 36K and 65K Mycobacterium leprae antigens defined by human T cell clones

    NARCIS (Netherlands)

    van Schooten, W. C.; Ottenhoff, T. H.; Klatser, P. R.; Thole, J.; de Vries, R. R.; Kolk, A. H.

    1988-01-01

    To identify the molecular localization and specificity of Mycobacterium leprae antigenic determinants inducing T cell activation, we studied the reactivity of M. leprae-reactive T cell clones from two tuberculoid leprosy patients towards a battery of different mycobacterial strains and purified

  2. Antigen-specific T cell activation independently of the MHC: chimeric antigen receptor (CAR-redirected T cells.

    Directory of Open Access Journals (Sweden)

    Hinrich eAbken

    2013-11-01

    Full Text Available Adoptive T cell therapy has recently shown powerful in initiating a lasting anti-tumor response with spectacular therapeutic success in some cases. Specific T cell therapy, however, is limited since a number of cancer cells are not recognized by T cells due to various mechanisms including the limited availability of tumor-specific T cells and deficiencies in antigen processing or major histocompatibility complex (MHC expression of cancer cells. To make adoptive cell therapy applicable for the broad variety of cancer entities, patient's T cells are engineered ex vivo with pre-defined specificity by a recombinant chimeric antigen receptor (CAR which consists in the extracellular part of an antibody-derived domain for binding with a tumor-associated antigen and in the intracellular part of a TCR-derived signaling moiety for T cell activation. The specificity of CAR mediated T cell recognition is defined by the antibody domain, is independent of MHC presentation and can be extended to any target for which an antibody is available. We discuss the advantages and limitations of MHC-independent T cell targeting by an engineered CAR and review most significant progress recently made in early stage clinical trials to treat cancer.

  3. NOD1 cooperates with TLR2 to enhance T cell receptor-mediated activation in CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Blandine C Mercier

    Full Text Available Pattern recognition receptors (PRR, like Toll-like receptors (TLR and NOD-like receptors (NLR, are involved in the detection of microbial infections and tissue damage by cells of the innate immune system. Recently, we and others have demonstrated that TLR2 can additionally function as a costimulatory receptor on CD8 T cells. Here, we establish that the intracytosolic receptor NOD1 is expressed and functional in CD8 T cells. We show that C12-iEDAP, a synthetic ligand for NOD1, has a direct impact on both murine and human CD8 T cells, increasing proliferation and effector functions of cells activated via their T cell receptor (TCR. This effect is dependent on the adaptor molecule RIP2 and is associated with an increased activation of the NF-κB, JNK and p38 signaling pathways. Furthermore, we demonstrate that NOD1 stimulation can cooperate with TLR2 engagement on CD8 T cells to enhance TCR-mediated activation. Altogether our results indicate that NOD1 might function as an alternative costimulatory receptor in CD8 T cells. Our study provides new insights into the function of NLR in T cells and extends to NOD1 the recent concept that PRR stimulation can directly control T cell functions.

  4. Increased autophagy in CD4(+) T cells of rheumatoid arthritis patients results in T-cell hyperactivation and apoptosis resistance

    NARCIS (Netherlands)

    van Loosdregt, Jorg; Rossetti, Maura; Spreafico, Roberto; Moshref, Maryam; Olmer, Merissa; Williams, Gary W; Kumar, Pavanish; Copeland, Dana; Pischel, Ken; Lotz, Martin; Albani, Salvatore

    2016-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease hallmarked by aberrant cellular homeostasis, resulting in hyperactive CD4(+) T cells that are more resistant to apoptosis. Both hyperactivation and resistance to apoptosis may contribute to the pathogenicity of CD4(+) T cells in the autoimmune

  5. T cell maturation stage prior to and during GMP processing informs on CAR T cell expansion in patients

    NARCIS (Netherlands)

    Y. Klaver (Yarne); S.C.L. van Steenbergen; S. Sleijfer (Stefan); J.E.M.A. Debets (Reno); C.H.J. Lamers (Cor)

    2016-01-01

    textabstractAutologous T cells were genetically modified to express a chimeric antigen receptor (CAR) directed toward carboxy-anhydrase-IX (CAIX) and used to treat patients with CAIX-positive metastatic renal cell carcinoma. In this study, we questioned whether the T cell maturation stage in the

  6. Characterization of tracked radiofrequency ablation in phantom

    International Nuclear Information System (INIS)

    Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

    2007-01-01

    In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4±0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA

  7. CD6 and Linker of Activated T Cells are Potential Interaction Partners for T Cell-Specific Adaptor Protein.

    Science.gov (United States)

    Hem, C D; Ekornhol, M; Granum, S; Sundvold-Gjerstad, V; Spurkland, A

    2017-02-01

    The T cell-specific adaptor protein (TSAd) contains several protein interaction domains, and is merging as a modulator of T cell activation. Several interaction partners for the TSAd proline-rich region and phosphotyrosines have been identified, including the Src and Tec family kinases lymphocyte-specific protein tyrosine kinase and interleukin 2-inducible T cell kinase. Via its Src homology 2 (SH2) domain, TSAd may thus function as a link between these enzymes and other signalling molecules. However, few binding partners to the TSAd SH2 domain in T cells are hitherto known. Through the use of in silico ligand prediction, peptide spot arrays, pull-down and immunoprecipitation experiments, we here report novel interactions between the TSAd SH2 domain and CD6 phosphotyrosine (pTyr) 629 and linker of activated T cells (LAT) pTyr 171 , pTyr 191 and pTyr 226 . © 2016 The Foundation for the Scandinavian Journal of Immunology.

  8. Peripheral Blood CCR4+CCR6+ and CXCR3+CCR6+ CD4+ T Cells Are Highly Permissive to HIV-1 Infection

    OpenAIRE

    Gosselin, Annie; Monteiro, Patricia; Chomont, Nicolas; Diaz-Griffero, Felipe; Said, Elias A.; Fonseca, Simone; Wacleche, Vanessa; El-Far, Mohamed; Boulassel, Mohamed-Rachid; Routy, Jean-Pierre; Sekaly, Rafick-Pierre; Ancuta, Petronela

    2009-01-01

    There is limited knowledge on the identity of primary CD4+ T cell subsets selectively targeted by HIV-1 in vivo. In this study, we established a link between HIV permissiveness, phenotype/homing potential, and lineage commitment in primary CD4+ T cells. CCR4+CCR6+, CCR4+CCR6−, CXCR3+CCR6+, and CXCR3+CCR6− T cells expressed cytokines and transcription factors specific for Th17, Th2, Th1Th17, and Th1 lineages, respectively. CCR4+CCR6+ and CXCR3+CCR6+ T cells expressed the HIV coreceptors CCR5 a...

  9. Enhancing the potency and specificity of engineered T cells for cancer treatment.

    Science.gov (United States)

    Sukumaran, Sujita; Watanabe, Norihiro; Bajgain, Pradip; Raja, Kanchana; Mohammed, Somala; Fisher, William E; Brenner, Malcolm K; Leen, Ann M; Vera, Juan F

    2018-06-07

    The adoptive transfer of chimeric antigen receptor (CAR)-modified T cells has produced tumor responses even in patients with refractory diseases. However, the paucity of antigens that are tumor selective has resulted, on occasion, in "on-target, off-tumor" toxicities. To address this issue, we developed an approach to render T cells responsive to an expression pattern present exclusively at the tumor by using a trio of novel chimeric receptors. Using pancreatic cancer as a model, we demonstrate how T cells engineered with receptors that recognize PSCA, TGFβ, and IL4, and whose endodomains recapitulate physiologic T cell signaling by providing signals for activation, co-stimulation and cytokine support, produce potent anti-tumor effects selectively at the tumor site. In addition, this strategy has the benefit of rendering our cells resistant to otherwise immunosuppressive cytokines (TGFβ and IL4) and can be readily extended to other inhibitory molecules present at the tumor site (e.g. PD-L1, IL10, IL13). Copyright ©2018, American Association for Cancer Research.

  10. Vγ9Vδ2 T cells as a promising innovative tool for immunotherapy of hematologic malignancies

    Directory of Open Access Journals (Sweden)

    Serena Meraviglia

    2011-12-01

    Full Text Available The potent anti-tumor activities of γδ T cells, their ability to produce pro-inflammatory cytokines, and their strong cytolytic activity have prompted the development of protocols in which γδ agonists or ex vivo-expanded γδ cells are administered to tumor patients. γδ T cells can be selectively activated by either synthetic phosphoantigens or by drugs that enhance their accumulation into stressed cells as aminobisphosphonates, thus offering new avenues for the development of γδ T cell-based immunotherapies. The recent development of small drugs selectively activating Vγ9Vδ2 T lymphocytes, which upregulate the endogenous phosphoantigens, has enabled the investigators to design the experimental approaches of cancer immunotherapies; several ongoing phase I and II clinical trials are focused on the role of the direct bioactivity of drugs and of adoptive cell therapies involving phosphoantigen- or aminobisphosphonate-activated Vγ9Vδ2 T lymphocytes in humans. In this review, we focus on the recent advances in the activation/expansion of γδ T cells in vitro and in vivo that may represent a promising target for the design of novel and highly innovative immunotherapy in patients with hematologic malignancies.

  11. Role of alveolar epithelial Early growth response-1 (Egr-1) in CD8+ T Cell mediated Lung Injury

    Science.gov (United States)

    Ramana, Chilakamarti V.; Cheng, Guang-Shing; Kumar, Aseem; Kwon, Hyung- Joo; Enelow, Richard I.

    2009-01-01

    Influenza infection of the distal airways results in severe lung injury, a considerable portion of which is immunopathologic and attributable to the host responses. We have used a mouse model to specifically investigate the role of antiviral CD8+ T cells in this injury, and have found that the critical effector molecule is TNF-α expressed by the T cells upon antigen recognition. Interestingly, the immunopathology which ensues is characterized by significant accumulation of host inflammatory cells, recruited by chemokines expressed by the target alveolar epithelial cells. In this study we analyzed the mechanisms involved in the induction of epithelial chemokine expression triggered by antigen-specific CD8+ T cell recognition, and demonstrate that the Early growth response-1 (Egr-1) transcription factor is rapidly induced in epithelial cells, both in vitro and ex vivo, and that this is a critical regulator of a host of inflammatory chemokines. Genetic deficiency of Egr-1 significantly abrogates both the chemokine expression and the immunopathologic injury associated with T cell recognition, and it directly regulates transcriptional activity of a model CXC chemokine, MIP-2. We further demonstrate that Egr-1 induction is triggered by TNF-α– dependent ERK activation, and inhibition of this pathway ablates Egr-1 expression. These findings suggest that Egr-1 may represent an important target in mitigating the immunopathology of severe influenza infection. PMID:19786304

  12. Role of alveolar epithelial early growth response-1 (Egr-1) in CD8+ T cell-mediated lung injury.

    Science.gov (United States)

    Ramana, Chilakamarti V; Cheng, Guang-Shing; Kumar, Aseem; Kwon, Hyung-Joo; Enelow, Richard I

    2009-12-01

    Influenza infection of the distal airways results in severe lung injury, a considerable portion of which is immunopathologic and attributable to the host responses. We have used a mouse model to specifically investigate the role of antiviral CD8(+) T cells in this injury, and have found that the critical effector molecule is TNF-alpha expressed by the T cells upon antigen recognition. Interestingly, the immunopathology which ensues is characterized by significant accumulation of host inflammatory cells, recruited by chemokines expressed by the target alveolar epithelial cells. In this study we analyzed the mechanisms involved in the induction of epithelial chemokine expression triggered by antigen-specific CD8(+) T cell recognition, and demonstrate that the early growth response-1 (Egr-1) transcription factor is rapidly induced in epithelial cells, both in vitro and ex vivo, and that this is a critical regulator of a host of inflammatory chemokines. Genetic deficiency of Egr-1 significantly abrogates both the chemokine expression and the immunopathologic injury associated with T cell recognition, and it directly regulates transcriptional activity of a model CXC chemokine, MIP-2. We further demonstrate that Egr-1 induction is triggered by TNF-alpha-dependent ERK activation, and inhibition of this pathway ablates Egr-1 expression. These findings suggest that Egr-1 may represent an important target in mitigating the immunopathology of severe influenza infection.

  13. Toward precision manufacturing of immunogene T-cell therapies.

    Science.gov (United States)

    Xu, Jun; Melenhorst, J Joseph; Fraietta, Joseph A

    2018-05-01

    Cancer can be effectively targeted using a patient's own T cells equipped with synthetic receptors, including chimeric antigen receptors (CARs) that redirect and reprogram these lymphocytes to mediate tumor rejection. Over the past two decades, several strategies to manufacture genetically engineered T cells have been proposed, with the goal of generating optimally functional cellular products for adoptive transfer. Based on this work, protocols for manufacturing clinical-grade CAR T cells have been established, but these complex methods have been used to treat only a few hundred individuals. As CAR T-cell therapy progresses into later-phase clinical trials and becomes an option for more patients, a major consideration for academic institutions and industry is developing robust manufacturing processes that will permit scaling-out production of immunogene T-cell therapies in a reproducible and efficient manner. In this review, we will discuss the steps involved in cell processing, the major obstacles surrounding T-cell manufacturing platforms and the approaches for improving cellular product potency. Finally, we will address the challenges of expanding CAR T-cell therapy to a global patient population. Copyright © 2018 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  14. T cells in multiple sclerosis and experimental autoimmune encephalomyelitis.

    LENUS (Irish Health Repository)

    Fletcher, J M

    2012-02-01

    Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS), which involves autoimmune responses to myelin antigens. Studies in experimental autoimmune encephalomyelitis (EAE), an animal model for MS, have provided convincing evidence that T cells specific for self-antigens mediate pathology in these diseases. Until recently, T helper type 1 (Th1) cells were thought to be the main effector T cells responsible for the autoimmune inflammation. However more recent studies have highlighted an important pathogenic role for CD4(+) T cells that secrete interleukin (IL)-17, termed Th17, but also IL-17-secreting gammadelta T cells in EAE as well as other autoimmune and chronic inflammatory conditions. This has prompted intensive study of the induction, function and regulation of IL-17-producing T cells in MS and EAE. In this paper, we review the contribution of Th1, Th17, gammadelta, CD8(+) and regulatory T cells as well as the possible development of new therapeutic approaches for MS based on manipulating these T cell subtypes.

  15. HIV-1 transgenic rats develop T cell abnormalities

    International Nuclear Information System (INIS)

    Reid, William; Abdelwahab, Sayed; Sadowska, Mariola; Huso, David; Neal, Ashley; Ahearn, Aaron; Bryant, Joseph; Gallo, Robert C.; Lewis, George K.; Reitz, Marvin

    2004-01-01

    HIV-1 infection leads to impaired antigen-specific T cell proliferation, increased susceptibility of T cells to apoptosis, progressive impairment of T-helper 1 (Th1) responses, and altered maturation of HIV-1-specific memory cells. We have identified similar impairments in HIV-1 transgenic (Tg) rats. Tg rats developed an absolute reduction in CD4 + and CD8 + T cells able to produce IFN-γ following activation and an increased susceptibility of T cells to activation-induced apoptosis. CD4 + and CD8 + effector/memory (CD45RC - CD62L - ) pools were significantly smaller in Tg rats compared to non-Tg controls, although the converse was true for the naieve (CD45RC + CD62L + ) T cell pool. Our interpretation is that the HIV transgene causes defects in the development of T cell effector function and generation of specific effector/memory T cell subsets, and that activation-induced apoptosis may be an essential factor in this process

  16. Role of innate T cells in anti-bacterial immunity

    Directory of Open Access Journals (Sweden)

    Yifang eGao

    2015-06-01

    Full Text Available Innate T cells are a heterogeneous group of αβ and γδ T cells that respond rapidly (<2 hours upon activation. These innate T cells also share a non MHC class I or II restriction requirement for antigen recognition. Three major populations within the innate T cell group are recognized, namely Invariant NKT cells (iNKT; Mucosal associated invariant T cells (MAIT and gamma delta T cells. These cells recognize foreign/self-lipid presented by non-classical MHC molecules, such as CD1d, MR1 and CD1a.They are activated during the early stages of bacterial infection and act as a bridge between the innate and adaptive immune systems. In this review we focus on the functional properties of these 3 innate T cell populations and how they are purposed for antimicrobial defense. Furthermore we address the mechanisms through which their effector functions are targeted for bacterial control and compare this in human and murine systems. Lastly we speculate on future roles of these cell types in therapeutic settings such as vaccination.

  17. The role of CD8+ T cells during allograft rejection

    Directory of Open Access Journals (Sweden)

    V. Bueno

    2002-11-01

    Full Text Available Organ transplantation can be considered as replacement therapy for patients with end-stage organ failure. The percent of one-year allograft survival has increased due, among other factors, to a better understanding of the rejection process and new immunosuppressive drugs. Immunosuppressive therapy used in transplantation prevents activation and proliferation of alloreactive T lymphocytes, although not fully preventing chronic rejection. Recognition by recipient T cells of alloantigens expressed by donor tissues initiates immune destruction of allogeneic transplants. However, there is controversy concerning the relative contribution of CD4+ and CD8+ T cells to allograft rejection. Some animal models indicate that there is an absolute requirement for CD4+ T cells in allogeneic rejection, whereas in others CD4-depleted mice reject certain types of allografts. Moreover, there is evidence that CD8+ T cells are more resistant to immunotherapy and tolerance induction protocols. An intense focal infiltration of mainly CD8+CTLA4+ T lymphocytes during kidney rejection has been described in patients. This suggests that CD8+ T cells could escape from immunosuppression and participate in the rejection process. Our group is primarily interested in the immune mechanisms involved in allograft rejection. Thus, we believe that a better understanding of the role of CD8+ T cells in allograft rejection could indicate new targets for immunotherapy in transplantation. Therefore, the objective of the present review was to focus on the role of the CD8+ T cell population in the rejection of allogeneic tissue.

  18. Asthma and gender impact accumulation of T cell subtypes

    Directory of Open Access Journals (Sweden)

    Peters Stephen P

    2010-07-01

    Full Text Available Abstract Background The "Th2 hypothesis for asthma" asserts that an increased ratio of Th2:Th1 cytokine production plays an important pathogenic role in asthma. Although widely embraced, the hypothesis has been challenged by various empirical observations and has been described as overly simplistic. We sought to establish whether CD3+CD28-mediated and antigen-independent accumulation of type 1 and type 2 T cells differs significantly between nonasthmatic and asthmatic populations. Methods An ex vivo system was used to characterize the regulation of IFN-γ-producing (type 1 and IL-13-producing (type 2 T cell accumulation in response to CD3+CD28 and IL-2 stimulation by flow cytometry. Results IL-13-producing T cells increased in greater numbers in response to antigen-independent stimulation in peripheral blood lymphocytes from female atopic asthmatic subjects compared with male asthmatics and both male and female atopic non-asthmatic subjects. IFN-γ+ T cells increased in greater numbers in response to either antigen-independent or CD3+CD28-mediated stimulation in peripheral blood lymphocytes from atopic asthmatic subjects compared to non-asthmatic subjects, regardless of gender. Conclusions We demonstrate that T cells from asthmatics are programmed for increased accumulation of both type 2 and type 1 T cells. Gender had a profound effect on the regulation of type 2 T cells, thus providing a mechanism for the higher frequency of adult asthma in females.

  19. Adoptive immunotherapy using PRAME-specific T cells in medulloblastoma.

    Science.gov (United States)

    Orlando, Domenico; Miele, Evelina; De Angelis, Biagio; Guercio, Marika; Boffa, Iolanda; Sinibaldi, Matilde; Po, Agnese; Caruana, Ignazio; Abballe, Luana; Carai, Andrea; Caruso, Simona; Camera, Antonio; Moseley, Annemarie; Hagedoorn, Renate S; Heemskerk, Mirjam H M; Giangaspero, Felice; Mastronuzzi, Angela; Ferretti, Elisabetta; Locatelli, Franco; Quintarelli, Concetta

    2018-04-03

    Medulloblastoma is the most frequent malignant childhood brain tumor with a high morbidity. Identification of new therapeutic targets would be instrumental in improving patient outcomes. We evaluated the expression of the tumor-associated antigen PRAME in biopsies from 60 medulloblastoma patients. PRAME expression was detectable in 82% of tissues independent of molecular and histopathologic subgroups. High PRAME expression also correlated with worse overall survival. We next investigated the relevance of PRAME as a target for immunotherapy. Medulloblastoma cells were targeted using genetically modified T cells with a PRAME-specific TCR (SLL TCR T cells). SLL TCR T cells efficiently killed medulloblastoma HLA-A*02+ DAOY cells as well as primary HLA-A*02+ medulloblastoma cells. Moreover, SLL TCR T cells controlled tumor growth in an orthotopic mouse model of medulloblastoma. To prevent unexpected T cell-related toxicity,an inducible caspase 9 (iC9) gene was introduced in frame with the SLL TCR; this safety switch triggered prompt elimination of genetically-modified T cells. Altogether, these data indicate that T cells genetically modified with a high-affinity, PRAME-specific TCR and iC9 may represent a promising innovative approach for treating HLA-A*02+ medulloblastoma patients. Copyright ©2018, American Association for Cancer Research.

  20. How to train your T cell: genetically engineered chimeric antigen receptor T cells versus bispecific T-cell engagers to target CD19 in B acute lymphoblastic leukemia.

    Science.gov (United States)

    Ruella, Marco; Gill, Saar

    2015-06-01

    Antigen-specific T cell-based immunotherapy is getting its day in the sun. The contemporaneous development of two potent CD19-specific immunotherapeutic modalities for the treatment of B-cell malignancies provides exciting opportunities for patients, physicians and scientists alike. Patients with relapsed, refractory or poor-risk B-cell acute lymphoblastic leukemia (ALL) previously had few therapeutic options and now have two potential new lifelines. Physicians will have the choice between two powerful modalities and indeed could potentially enroll some patients on trials exploring both modalities if needed. For scientists interested in tumor immunology, the advent of chimeric antigen receptor T-cell therapy and of bispecific T-cell engagers (BiTEs) provides unprecedented opportunities to explore the promise and limitations of antigen-specific T-cell therapy in the context of human leukemia. In this article, we compare chimeric antigen receptor T cells and BiTEs targeting CD19 in B-cell ALL in the setting of the available clinical literature.

  1. MicroRNA-4443 Causes CD4+ T Cells Dysfunction by Targeting TNFR-Associated Factor 4 in Graves’ Disease

    Directory of Open Access Journals (Sweden)

    Yicheng Qi

    2017-11-01

    Full Text Available ContextAberrant CD4+ T cell function plays a critical role in the process of Graves’ disease (GD. MicroRNAs (miRNAs are important regulators of T cell activation, proliferation, and cytokine production. However, the contribution of miRNAs to CD4+ T cell dysfunction in GD remains unclear.ObjectiveTo investigate how certain miRNA causes aberrant CD4+ T cell function in GD patients.MethodsWe compared the expression pattern of miRNAs in CD4+ T cells from untreated GD (UGD patients with those from healthy controls. The most significantly dysregulated miRNAs were selected and their correlations with clinical parameters were analyzed. The effect of miR-4443 on CD4+ T cells cytokines production and proliferation was assessed. The potential gene target was identified and validated.ResultsGD patients had unique pattern of miRNA expression profile in CD4+ T cells comparing to healthy subjects. miR-10a, miR-125b, and miR-4443 were the three most significantly dysregulated miRNAs. The elevated miR-4443 levels were strongly correlated with clinical parameters in an independent dataset of UGD patients (N = 40, while miR-4443 was normally expressed in GD patients with euthyroidism and negative TRAb level. We found that miR-4443 directly inhibited TNFR-associated factor (TRAF 4 expression to increase CD4+ T cells cytokines secretion as well as proliferation through the NF-κB pathway. Furthermore, the TRAF4 levels in GD patients were inversely correlated with miR-4443, and knocking down TRAF4 had a similar effect with miR-4443 overexpression.ConclusionThe increased expression of miR-4443 induced CD4+ T cells dysfunction by targeting TRAF4, which may cause GD.

  2. Mucorales-Specific T Cells in Patients with Hematologic Malignancies.

    Science.gov (United States)

    Potenza, Leonardo; Vallerini, Daniela; Barozzi, Patrizia; Riva, Giovanni; Gilioli, Andrea; Forghieri, Fabio; Candoni, Anna; Cesaro, Simone; Quadrelli, Chiara; Maertens, Johan; Rossi, Giulio; Morselli, Monica; Codeluppi, Mauro; Mussini, Cristina; Colaci, Elisabetta; Messerotti, Andrea; Paolini, Ambra; Maccaferri, Monica; Fantuzzi, Valeria; Del Giovane, Cinzia; Stefani, Alessandro; Morandi, Uliano; Maffei, Rossana; Marasca, Roberto; Narni, Franco; Fanin, Renato; Comoli, Patrizia; Romani, Luigina; Beauvais, Anne; Viale, Pier Luigi; Latgè, Jean Paul; Lewis, Russell E; Luppi, Mario

    2016-01-01

    Invasive mucormycosis (IM) is an emerging life-threatening fungal infection. It is difficult to obtain a definite diagnosis and to initiate timely intervention. Mucorales-specific T cells occur during the course of IM and are involved in the clearance of the infection. We have evaluated the feasibility of detecting Mucorales-specific T cells in hematological patients at risk for IM, and have correlated the detection of such cells with the clinical conditions of the patients. By using an enzyme linked immunospot assay, the presence of Mucorales-specific T cells in peripheral blood (PB) samples has been investigated at three time points during high-dose chemotherapy for hematologic malignancies. Mucorales-specific T cells producing interferon-γ, interleukin-10 and interleukin-4 were analysed in order to detect a correlation between the immune response and the clinical picture. Twenty-one (10.3%) of 204 patients, accounting for 32 (5.3%) of 598 PB samples, tested positive for Mucorales-specific T cells. Two groups could be identified. Group 1, including 15 patients without signs or symptoms of invasive fungal diseases (IFD), showed a predominance of Mucorales-specific T cells producing interferon-gamma. Group 2 included 6 patients with a clinical picture consistent with invasive fungal disease (IFD): 2 cases of proven IM and 4 cases of possible IFD. The proven patients had significantly higher number of Mucorales-specific T cells producing interleukin-10 and interleukin-4 and higher rates of positive samples by using derived diagnostic cut-offs when compared with the 15 patients without IFD. Mucorales-specific T cells can be detected and monitored in patients with hematologic malignancies at risk for IM. Mucorales-specific T cells polarized to the production of T helper type 2 cytokines are associated with proven IM and may be evaluated as a surrogate diagnostic marker for IM.

  3. Mucorales-Specific T Cells in Patients with Hematologic Malignancies.

    Directory of Open Access Journals (Sweden)

    Leonardo Potenza

    Full Text Available Invasive mucormycosis (IM is an emerging life-threatening fungal infection. It is difficult to obtain a definite diagnosis and to initiate timely intervention. Mucorales-specific T cells occur during the course of IM and are involved in the clearance of the infection. We have evaluated the feasibility of detecting Mucorales-specific T cells in hematological patients at risk for IM, and have correlated the detection of such cells with the clinical conditions of the patients.By using an enzyme linked immunospot assay, the presence of Mucorales-specific T cells in peripheral blood (PB samples has been investigated at three time points during high-dose chemotherapy for hematologic malignancies. Mucorales-specific T cells producing interferon-γ, interleukin-10 and interleukin-4 were analysed in order to detect a correlation between the immune response and the clinical picture. Twenty-one (10.3% of 204 patients, accounting for 32 (5.3% of 598 PB samples, tested positive for Mucorales-specific T cells. Two groups could be identified. Group 1, including 15 patients without signs or symptoms of invasive fungal diseases (IFD, showed a predominance of Mucorales-specific T cells producing interferon-gamma. Group 2 included 6 patients with a clinical picture consistent with invasive fungal disease (IFD: 2 cases of proven IM and 4 cases of possible IFD. The proven patients had significantly higher number of Mucorales-specific T cells producing interleukin-10 and interleukin-4 and higher rates of positive samples by using derived diagnostic cut-offs when compared with the 15 patients without IFD.Mucorales-specific T cells can be detected and monitored in patients with hematologic malignancies at risk for IM. Mucorales-specific T cells polarized to the production of T helper type 2 cytokines are associated with proven IM and may be evaluated as a surrogate diagnostic marker for IM.

  4. CD4+ T Cells Mediate Aspergillosis Vaccine Protection.

    Science.gov (United States)

    Diaz-Arevalo, Diana; Kalkum, Markus

    2017-01-01

    Adaptive effector CD4 + T cells play essential roles in the defense against fungal infections, especially against invasive aspergillosis (IA). Such protective CD4 + T cells can be generated through immunization with specialized antifungal vaccines, as has been demonstrated for pulmonary Aspergillus fumigatus infections in mouse experiments. Adaptive transfer of fungal antigen-specific CD4 + T cells conferred protection onto non-immunized naive mice, an experimental approach that could potentially become a future treatment option for immunosuppressed IA patients, focusing on the ultimate goal to improve their otherwise dim chances for survival. Here, we describe the different techniques to analyze CD4 + T cell immune responses after immunization with a recombinant fungal protein. We present three major methods that are used to analyze the role of CD4 + T cells in protection against A. fumigatus challenge. They include (1) transplantation of CD4 + T cells from vaccinated mice into immunosuppressed naive mice, observing increasing protection of the cell recipients, (2) depletion of CD4 + T cells from vaccinated mice, which abolishes vaccine protection, and (3) T cell proliferation studies following stimulation with overlapping synthetic peptides or an intact protein vaccine. The latter can be used to validate immunization status and to identify protective T cell epitopes in vaccine antigens. In the methods detailed here, we used versions of the well-studied Asp f3 protein expressed in a bacterial host, either as the intact full length protein or its N-terminally truncated version, comprised of residues 15-168. However, these methods are generally applicable and can well be adapted to study other protein-based subunit vaccines.

  5. The SKINT1-like gene is inactivated in hominoids but not in all primate species: implications for the origin of dendritic epidermal T cells.

    Directory of Open Access Journals (Sweden)

    Rania Hassan Mohamed

    Full Text Available Dendritic epidermal T cells, which express an invariant Vγ5Vδ1 T-cell receptor and account for 95% of all resident T cells in the mouse epidermis, play a critical role in skin immune surveillance. These γδ T cells are generated by positive selection in the fetal thymus, after which they migrate to the skin. The development of dendritic epidermal T cells is critically dependent on the Skint1 gene expressed specifically in keratinocytes and thymic epithelial cells, suggesting an indispensable role for Skint1 in the selection machinery for specific intraepithelial lymphocytes. Phylogenetically, rodents have functional SKINT1 molecules, but humans and chimpanzees have a SKINT1-like (SKINT1L gene with multiple inactivating mutations. In the present study, we analyzed SKINT1L sequences in representative primate species and found that all hominoid species have a common inactivating mutation, but that Old World monkeys such as olive baboons, green monkeys, cynomolgus macaques and rhesus macaques have apparently functional SKINT1L sequences, indicating that SKINT1L was inactivated in a common ancestor of hominoids. Interestingly, the epidermis of cynomolgus macaques contained a population of dendritic-shaped γδ T cells expressing a semi-invariant Vγ10/Vδ1 T-cell receptor. However, this population of macaque T cells differed from rodent dendritic epidermal T cells in that their Vγ10/Vδ1 T-cell receptors displayed junctional diversity and expression of Vγ10 was not epidermis-specific. Therefore, macaques do not appear to have rodent-type dendritic epidermal T cells despite having apparently functional SKINT1L. Comprehensive bioinformatics analysis indicates that SKINT1L emerged in an ancestor of placental mammals but was inactivated or lost multiple times in mammalian evolution and that Skint1 arose by gene duplication in a rodent lineage, suggesting that authentic dendritic epidermal T cells are presumably unique to rodents.

  6. Regulatory T cells and B cells: implication on autoimmune diseases

    OpenAIRE

    Wang, Ping; Zheng, Song Guo

    2013-01-01

    The regulatory T (Treg) cells play an important role in the maintenance of homeostasis and the prevention of autoimmune diseases. Although most studies are focusing on the role of Treg cells in T cells and T cells-mediated diseases, these cells also directly affect B cells and other non-T cells. This manuscript updates the role of Treg cells on the B cells and B cell-mediated diseases. In addition, the mechanisms whereby Treg cells suppress B cell responses have been discussed.

  7. Identification of CD8(+) T Cell Epitopes in the West Nile Virus Polyprotein by Reverse-Immunology Using NetCTL

    DEFF Research Database (Denmark)

    Larsen, Mette Voldby; Lelic, A.; Parsons, R.

    2010-01-01

    bioinformatics methods to predict WNV-specific CD8(+) T cell epitopes and selected a set of peptides that constitutes maximum coverage of 20 fully-sequenced WNV strains. We then tested these putative epitopes for cellular reactivity in a cohort of WNV-infected patients. We identified 26 new CD8(+) T cell...

  8. Pellet ablation and ablation model development

    International Nuclear Information System (INIS)

    Houlberg, W.A.

    1989-01-01

    A broad survey of pellet ablation is given, based primarily on information presented at this meeting. The implications of various experimental observations for ablation theory are derived from qualitative arguments of the physics involved. The major elements of a more complete ablation theory are then outlined in terms of these observations. This is followed by a few suggestions on improving the connections between theory and experimental results through examination of ablation data. Although this is a rather aggressive undertaking for such a brief (and undoubtedly incomplete) assessment, some of the discussion may help us advance the understanding of pellet ablation. 17 refs

  9. Comprehensive Approach for Identifying the T Cell Subset Origin of CD3 and CD28 Antibody-Activated Chimeric Antigen Receptor-Modified T Cells.

    Science.gov (United States)

    Schmueck-Henneresse, Michael; Omer, Bilal; Shum, Thomas; Tashiro, Haruko; Mamonkin, Maksim; Lapteva, Natalia; Sharma, Sandhya; Rollins, Lisa; Dotti, Gianpietro; Reinke, Petra; Volk, Hans-Dieter; Rooney, Cliona M

    2017-07-01

    The outcome of therapy with chimeric Ag receptor (CAR)-modified T cells is strongly influenced by the subset origin of the infused T cells. However, because polyclonally activated T cells acquire a largely CD45RO + CCR7 - effector memory phenotype after expansion, regardless of subset origin, it is impossible to know which subsets contribute to the final T cell product. To determine the contribution of naive T cell, memory stem T cell, central memory T cell, effector memory T cell, and terminally differentiated effector T cell populations to the CD3 and CD28-activated CAR-modified T cells that we use for therapy, we followed the fate and function of individually sorted CAR-modified T cell subsets after activation with CD3 and CD28 Abs (CD3/28), transduction and culture alone, or after reconstitution into the relevant subset-depleted population. We show that all subsets are sensitive to CAR transduction, and each developed a distinct T cell functional profile during culture. Naive-derived T cells showed the greatest rate of proliferation but had more limited effector functions and reduced killing compared with memory-derived populations. When cultured in the presence of memory T cells, naive-derived T cells show increased differentiation, reduced effector cytokine production, and a reduced reproliferative response to CAR stimulation. CD3/28-activated T cells expanded in IL-7 and IL-15 produced greater expansion of memory stem T cells and central memory T cell-derived T cells compared with IL-2. Our strategy provides a powerful tool to elucidate the characteristics of CAR-modified T cells, regardless of the protocol used for expansion, reveals the functional properties of each expanded T cell subset, and paves the way for a more detailed evaluation of the effects of manufacturing changes on the subset contribution to in vitro-expanded T cells. Copyright © 2017 by The American Association of Immunologists, Inc.

  10. Co-stimulatory signaling determines tumor antigen sensitivity and persistence of CAR T cells targeting PSCA+ metastatic prostate cancer.

    Science.gov (United States)

    Priceman, Saul J; Gerdts, Ethan A; Tilakawardane, Dileshni; Kennewick, Kelly T; Murad, John P; Park, Anthony K; Jeang, Brook; Yamaguchi, Yukiko; Yang, Xin; Urak, Ryan; Weng, Lihong; Chang, Wen-Chung; Wright, Sarah; Pal, Sumanta; Reiter, Robert E; Wu, Anna M; Brown, Christine E; Forman, Stephen J

    2018-01-01

    Advancing chimeric antigen receptor (CAR)-engineered adoptive T cells for the treatment of solid cancers is a major focus in the field of immunotherapy, given impressive recent clinical responses in hematological malignancies. Prostate cancer may be amenable to T cell-based immunotherapy since several tumor antigens, including prostate stem-cell antigen (PSCA), are widely over-expressed in metastatic disease. While antigen selectivity of CARs for solid cancers is crucial, it is problematic due to the absence of truly restricted tumor antigen expression and potential safety concerns with "on-target off-tumor" activity. Here, we show that the intracellular co-stimulatory signaling domain can determine a CAR's sensitivity for tumor antigen expression. A 4-1BB intracellular co-stimulatory signaling domain in PSCA-CARs confers improved selectivity for higher tumor antigen density, reduced T cell exhaustion phenotype, and equivalent tumor killing ability compared to PSCA-CARs containing the CD28 co-stimulatory signaling domain. PSCA-CARs exhibit robust in vivo anti-tumor activity in patient-derived bone-metastatic prostate cancer xenograft models, and 4-1BB-containing CARs show superior T cell persistence and control of disease compared with CD28-containing CARs. Our study demonstrates the importance of co-stimulation in defining an optimal CAR T cell, and also highlights the significance of clinically relevant models in developing solid cancer CAR T cell therapies.

  11. Co-stimulatory signaling determines tumor antigen sensitivity and persistence of CAR T cells targeting PSCA+ metastatic prostate cancer

    Science.gov (United States)

    Priceman, Saul J.; Gerdts, Ethan A.; Tilakawardane, Dileshni; Kennewick, Kelly T.; Murad, John P.; Park, Anthony K.; Jeang, Brook; Yamaguchi, Yukiko; Urak, Ryan; Weng, Lihong; Chang, Wen-Chung; Wright, Sarah; Pal, Sumanta; Reiter, Robert E.; Brown, Christine E.; Forman, Stephen J.

    2018-01-01

    ABSTRACT Advancing chimeric antigen receptor (CAR)-engineered adoptive T cells for the treatment of solid cancers is a major focus in the field of immunotherapy, given impressive recent clinical responses in hematological malignancies. Prostate cancer may be amenable to T cell-based immunotherapy since several tumor antigens, including prostate stem-cell antigen (PSCA), are widely over-expressed in metastatic disease. While antigen selectivity of CARs for solid cancers is crucial, it is problematic due to the absence of truly restricted tumor antigen expression and potential safety concerns with “on-target off-tumor” activity. Here, we show that the intracellular co-stimulatory signaling domain can determine a CAR's sensitivity for tumor antigen expression. A 4-1BB intracellular co-stimulatory signaling domain in PSCA-CARs confers improved selectivity for higher tumor antigen density, reduced T cell exhaustion phenotype, and equivalent tumor killing ability compared to PSCA-CARs containing the CD28 co-stimulatory signaling domain. PSCA-CARs exhibit robust in vivo anti-tumor activity in patient-derived bone-metastatic prostate cancer xenograft models, and 4-1BB-containing CARs show superior T cell persistence and control of disease compared with CD28-containing CARs. Our study demonstrates the importance of co-stimulation in defining an optimal CAR T cell, and also highlights the significance of clinically relevant models in developing solid cancer CAR T cell therapies. PMID:29308300

  12. Dynamics of human T-cell lymphotropic virus I (HTLV-I) infection of CD4+ T-cells.

    Science.gov (United States)

    Katri, Patricia; Ruan, Shigui

    2004-11-01

    Stilianakis and Seydel (Bull. Math. Biol., 1999) proposed an ODE model that describes the T-cell dynamics of human T-cell lymphotropic virus I (HTLV-I) infection and the development of adult T-cell leukemia (ATL). Their model consists of four components: uninfected healthy CD4+ T-cells, latently infected CD4+ T-cells, actively infected CD4+ T-cells, and ATL cells. Mathematical analysis that completely determines the global dynamics of this model has been done by Wang et al. (Math. Biosci., 2002). In this note, we first modify the parameters of the model to distinguish between contact and infectivity rates. Then we introduce a discrete time delay to the model to describe the time between emission of contagious particles by active CD4+ T-cells and infection of pure cells. Using the results in Culshaw and Ruan (Math. Biosci., 2000) in the analysis of time delay with respect to cell-free viral spread of HIV, we study the effect of time delay on the stability of the endemically infected equilibrium. Numerical simulations are presented to illustrate the results.

  13. Membrane-bound Dickkopf-1 in Foxp3+ regulatory T cells suppresses T-cell-mediated autoimmune colitis.

    Science.gov (United States)

    Chae, Wook-Jin; Park, Jong-Hyun; Henegariu, Octavian; Yilmaz, Saliha; Hao, Liming; Bothwell, Alfred L M

    2017-10-01

    Induction of tolerance is a key mechanism to maintain or to restore immunological homeostasis. Here we show that Foxp3 + regulatory T (Treg) cells use Dickkopf-1 (DKK-1) to regulate T-cell-mediated tolerance in the T-cell-mediated autoimmune colitis model. Treg cells from DKK-1 hypomorphic doubleridge mice failed to control CD4 + T-cell proliferation, resulting in CD4 T-cell-mediated autoimmune colitis. Thymus-derived Treg cells showed a robust expression of DKK-1 but not in naive or effector CD4 T cells. DKK-1 expression in Foxp3 + Treg cells was further increased upon T-cell receptor stimulation in vitro and in vivo. Interestingly, Foxp3 + Treg cells expressed DKK-1 in the cell membrane and the functional inhibition of DKK-1 using DKK-1 monoclonal antibody abrogated the suppressor function of Foxp3 + Treg cells. DKK-1 expression was dependent on de novo protein synthesis and regulated by the mitogen-activated protein kinase pathway but not by the canonical Wnt pathway. Taken together, our results highlight membrane-bound DKK-1 as a novel Treg-derived mediator to maintain immunological tolerance in T-cell-mediated autoimmune colitis. © 2017 The Authors. Immunology Published by John Wiley & Sons Ltd.

  14. c-MPL provides tumor-targeted T-cell receptor-transgenic T cells with costimulation and cytokine signals.

    Science.gov (United States)

    Nishimura, Christopher D; Brenner, Daniel A; Mukherjee, Malini; Hirsch, Rachel A; Ott, Leah; Wu, Meng-Fen; Liu, Hao; Dakhova, Olga; Orange, Jordan S; Brenner, Malcolm K; Lin, Charles Y; Arber, Caroline

    2017-12-21

    Adoptively transferred T-cell receptor (TCR)-engineered T cells depend on host-derived costimulation and cytokine signals for their full and sustained activation. However, in patients with cancer, both signals are frequently impaired. Hence, we developed a novel strategy that combines both essential signals in 1 transgene by expressing the nonlymphoid hematopoietic growth factor receptor c-MPL (myeloproliferative leukemia), the receptor for thrombopoietin (TPO), in T cells. c-MPL signaling activates pathways shared with conventional costimulatory and cytokine receptor signaling. Thus, we hypothesized that host-derived TPO, present in the tumor microenvironment, or pharmacological c-MPL agonists approved by the US Food and Drug Administration could deliver both signals to c-MPL-engineered TCR-transgenic T cells. We found that c-MPL + polyclonal T cells expand and proliferate in response to TPO, and persist longer after adoptive transfer in immunodeficient human TPO-transgenic mice. In TCR-transgenic T cells, c-MPL activation enhances antitumor function, T-cell expansion, and cytokine production and preserves a central memory phenotype. c-MPL signaling also enables sequential tumor cell killing, enhances the formation of effective immune synapses, and improves antileukemic activity in vivo in a leukemia xenograft model. We identify the type 1 interferon pathway as a molecular mechanism by which c-MPL mediates immune stimulation in T cells. In conclusion, we present a novel immunotherapeutic strategy using c-MPL-enhanced transgenic T cells responding to either endogenously produced TPO (a microenvironment factor in hematologic malignancies) or c-MPL-targeted pharmacological agents. © 2017 by The American Society of Hematology.

  15. Human rotavirus specific T cells: quantification by ELISPOT and expression of homing receptors on CD4+ T cells

    International Nuclear Information System (INIS)

    Rojas, Olga Lucia; Gonzale