Targeting MOG expression to dendritic cells delays onset of experimental autoimmune disease.

PubMed

Ko, Hyun-Ja; Chung, Jie-Yu; Nasa, Zeyad; Chan, James; Siatskas, Christopher; Toh, Ban-Hock; Alderuccio, Frank

2011-05-01

Haematopoietic stem cell (HSC) transfer coupled with gene therapy is a powerful approach to treating fatal diseases such as X-linked severe combined immunodeficiency. This ability to isolate and genetically manipulate HSCs also offers a strategy for inducing immune tolerance through ectopic expression of autoantigens. We have previously shown that retroviral transduction of bone marrow (BM) with vectors encoding the autoantigen, myelin oligodendrocyte glycoprotein (MOG), can prevent the induction of experimental autoimmune encephalomyelitis (EAE). However, ubiquitous cellular expression of autoantigen driven by retroviral promoters may not be the best approach for clinical translation and a targeted expression approach may be more acceptable. As BM-derived dendritic cells (DCs) play a major role in tolerance induction, we asked whether targeted expression of MOG, a target autoantigen in EAE, to DCs can promote tolerance induction and influence the development of EAE. Self-inactivating retroviral vectors incorporating the mouse CD11c promoter were generated and used to transduce mouse BM cells. Transplantation of gene-modified cells into irradiated recipients resulted in the generation of chimeric mice with transgene expression limited to DCs. Notably, chimeric mice transplanted with MOG-expressing BM cells manifest a significant delay in the development of EAE suggesting that targeted antigen expression to tolerogenic cell types may be a feasible approach to inducing antigen-specific tolerance.

MHC-mismatched mixed chimerism restores peripheral tolerance of noncross-reactive autoreactive T cells in NOD mice

PubMed Central

Zhang, Mingfeng; Racine, Jeremy J.; Lin, Qing; Liu, Yuqing; Tang, Shanshan; Qin, Qi; Qi, Tong; Riggs, Arthur D.; Zeng, Defu

2018-01-01

Autoimmune type 1 diabetes (T1D) and other autoimmune diseases are associated with particular MHC haplotypes and expansion of autoreactive T cells. Induction of MHC-mismatched but not -matched mixed chimerism by hematopoietic cell transplantation effectively reverses autoimmunity in diabetic nonobese diabetic (NOD) mice, even those with established diabetes. As expected, MHC-mismatched mixed chimerism mediates deletion in the thymus of host-type autoreactive T cells that have T-cell receptor (TCR) recognizing (cross-reacting with) donor-type antigen presenting cells (APCs), which have come to reside in the thymus. However, how MHC-mismatched mixed chimerism tolerizes host autoreactive T cells that recognize only self-MHC–peptide complexes remains unknown. Here, using NOD.Rag1−/−.BDC2.5 or NOD.Rag1−/−.BDC12-4.1 mice that have only noncross-reactive transgenic autoreactive T cells, we show that induction of MHC-mismatched but not -matched mixed chimerism restores immune tolerance of peripheral noncross-reactive autoreactive T cells. MHC-mismatched mixed chimerism results in increased percentages of both donor- and host-type Foxp3+ Treg cells and up-regulated expression of programmed death-ligand 1 (PD-L1) by host-type plasmacytoid dendritic cells (pDCs). Furthermore, adoptive transfer experiments showed that engraftment of donor-type dendritic cells (DCs) and expansion of donor-type Treg cells are required for tolerizing the noncross-reactive autoreactive T cells in the periphery, which are in association with up-regulation of host-type DC expression of PD-L1 and increased percentage of host-type Treg cells. Thus, induction of MHC-mismatched mixed chimerism may establish a peripheral tolerogenic DC and Treg network that actively tolerizes autoreactive T cells, even those with no TCR recognition of the donor APCs. PMID:29463744

Dendritic cells in oral tolerance in the gut.

PubMed

Rescigno, Maria

2011-09-01

Oral tolerance is a process that allows generation of systemic unresponsiveness to food antigens. Hence if the same antigen is introduced systemically even under immunogenic conditions it does not induce immune responsiveness. Dendritic cells (DCs) have been identified as essential players in this process. DCs in the gut are located in a strategic position as they can interact directly with luminal antigens or indirectly after their transcytosis across epithelial cells. DCs can then migrate to associated lymphoid tissues to induce tolerance. Antigen presenting cells in the gut are specialized in function and have divided their labour so that there are cells capable to migrate to the draining mesenteric lymph node for induction of T regulatory cells, while other subsets are resident and are required to enforce tolerance locally in the gut after food antigen exposure. In this review, I shall summarize the characteristics of antigen presenting cells in the gut and their involvement in oral tolerance induction. In addition, I will also emphasize that tolerance to food allergens may be contributed by plasmacytoid DCs in the liver that participate to the elimination or anergy of allergen-specific CD8 T cells. Hence specialized functions are associated to different subsets of antigen presenting cells and different organs. © 2011 Blackwell Publishing Ltd.

A miRNA181a/NFAT5 axis links impaired T cell tolerance induction with autoimmune type 1 diabetes

PubMed Central

Serr, Isabelle; Scherm, Martin G.; Zahm, Adam M.; Schug, Jonathan; Flynn, Victoria K.; Hippich, Markus; Kälin, Stefanie; Becker, Maike; Achenbach, Peter; Nikolaev, Alexei; Gerlach, Katharina; Liebsch, Nicole; Loretz, Brigitta; Lehr, Claus-Michael; Kirchner, Benedikt; Spornraft, Melanie; Haase, Bettina; Segars, James; Küper, Christoph; Palmisano, Ralf; Waisman, Ari; Willis, Richard A.; Kim, Wan-Uk; Weigmann, Benno; Kaestner, Klaus H.; Ziegler, Anette-Gabriele; Daniel, Carolin

2018-01-01

Molecular checkpoints that trigger the onset of islet autoimmunity or progression to human type 1 diabetes (T1D) are incompletely understood. Using T cells from children at an early stage of islet autoimmunity without clinical T1D, we find that a microRNA181a (miRNA181a)–mediated increase in signal strength of stimulation and costimulation links nuclear factor of activated T cells 5 (NFAT5) with impaired tolerance induction and autoimmune activation. We show that enhancing miRNA181a activity increases NFAT5 expression while inhibiting FOXP3+ regulatory T cell (Treg) induction in vitro. Accordingly, Treg induction is improved using T cells from NFAT5 knockout (NFAT5ko) animals, whereas altering miRNA181a activity does not affect Treg induction in NFAT5ko T cells. Moreover, high costimulatory signals result in phosphoinositide 3-kinase (PI3K)–mediated NFAT5, which interferes with FoxP3+ Treg induction. Blocking miRNA181a or NFAT5 increases Treg induction in murine and humanized models and reduces murine islet autoimmunity in vivo. These findings suggest targeting miRNA181a and/or NFAT5 signaling for the development of innovative personalized medicines to limit islet autoimmunity. PMID:29298866

The GARP/Latent TGF-β1 complex on Treg cells modulates the induction of peripherally derived Treg cells during oral tolerance.

PubMed

Edwards, Justin P; Hand, Timothy W; Morais da Fonseca, Denise; Glass, Deborah D; Belkaid, Yasmine; Shevach, Ethan M

2016-06-01

Treg cells can secrete latent TGF-β1 (LTGF-β1), but can also utilize an alternative pathway for transport and expression of LTGF-β1 on the cell surface in which LTGF-β1 is coupled to a distinct LTGF-β binding protein termed glycoprotein A repetitions predominant (GARP)/LRRC32. The function of the GARP/LTGF-β1 complex has remained elusive. Here, we examine in vivo the roles of GARP and TGF-β1 in the induction of oral tolerance. When Foxp3(-) OT-II T cells were transferred to wild-type recipient mice followed by OVA feeding, the conversion of Foxp3(-) to Foxp3(+) OT-II cells was dependent on recipient Treg cells. Neutralization of IL-2 in the recipient mice also abrogated this conversion. The GARP/LTGF-β1 complex on recipient Treg cells, but not dendritic cell-derived TGF-β1, was required for efficient induction of Foxp3(+) T cells and for the suppression of delayed hypersensitivity. Expression of the integrin αvβ8 by Treg cells (or T cells) in the recipients was dispensable for induction of Foxp3 expression. Transient depletion of the bacterial flora enhanced the development of oral tolerance by expanding Treg cells with enhanced expression of the GARP/LTGF-β1 complex. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

T-cell receptor revision: friend or foe?

PubMed

Hale, J Scott; Fink, Pamela J

2010-04-01

T-cell receptor (TCR) revision is a process of tolerance induction by which peripheral T cells lose surface expression of an autoreactive TCR, reinduce expression of the recombinase machinery, rearrange genes encoding extrathymically generated TCRs for antigen, and express these new receptors on the cell surface. We discuss the evidence for this controversial tolerance mechanism below. Despite the apparent heresy of post-thymic gene rearrangement, we argue here that TCR revision follows the rules obeyed by maturing thymocytes undergoing gene recombination. Expression of the recombinase is carefully controlled both spatially and temporally, and may be initiated by loss of signals through surface TCRs. The resulting TCR repertoire is characterized by its diversity, self major histocompatibility complex restriction, self tolerance, and ability to mount productive immune responses specific for foreign antigens. Hence, TCR revision is a carefully regulated process of tolerance induction that can contribute to the protection of the individual against invading pathogens while preserving the integrity of self tissue.

Change in the Content of Immunoproteasomes and Macrophages in Rat Liver At the Induction of Donor-Specific Tolerance.

PubMed

Karpova, Ya D; Ustichenko, V D; Alabedal'karim, N M; Stepanova, A A; Lyupina, Yu V; Boguslavski, K I; Bozhok, G A; Sharova, N P

2017-01-01

Induction of donor specific tolerance (DST) by the introduction of donor cells into a recipient's portal vein is one of the approaches used to solve the problem of transplant engraftment. However, the mechanism of DST development remains unclear to this moment. In the present work, we first studied the change in the content of immunoproteasomes and macrophages of the liver at early stages of the development of allospecific portal tolerance in rats by Western blotting and flow cytofluorimetry. On the basis of the data obtained, we can conclude that the induction of DST is an active process characterized by two phases during which the level of the proteasome immune subunits LMP2 and LMP7 in liver mononuclear cells, including Kupffer cells, and the number of Kupffer cells change. The first phase lasts up to 5 days after the beginning of DST induction; the second phase - from 5 to 14 days. In both phases, the level of the subunits LMP2 and LMP7 in the total pool of mononuclear cells and Kupffer cells increases, with maximum values on days 1 and 7. In addition, the total number of Kupffer cells increases in both phases with a shift in several days. The most noticeable changes take place in the second phase. The third day is characterized by a lower content of mononuclear cells expressing immunoproteasomes compared to the control value in native animals. Presumably, at this time point a "window of opportunity" appears for subsequent filling of an empty niche with cells of different subpopulations and, depending on this fact, the development of tolerance or rejection. The results obtained raise the new tasks of finding ways to influence the cellular composition in the liver and the expression of immunoproteasomes on the third day after the beginning of DST induction to block the development of rejection.

Type 1 diabetes vaccine candidates promote human Foxp3+Treg induction in humanized mice

PubMed Central

Serr, Isabelle; Fürst, Rainer W.; Achenbach, Peter; Scherm, Martin G.; Gökmen, Füsun; Haupt, Florian; Sedlmeier, Eva-Maria; Knopff, Annette; Shultz, Leonard; Willis, Richard A.; Ziegler, Anette-Gabriele; Daniel, Carolin

2016-01-01

Immune tolerance is executed partly by Foxp3+regulatory T (Treg) cells, which suppress autoreactive T cells. In autoimmune type 1 diabetes (T1D) impaired tolerance promotes destruction of insulin-producing β-cells. The development of autoantigen-specific vaccination strategies for Foxp3+Treg-induction and prevention of islet autoimmunity in patients is still in its infancy. Here, using human haematopoietic stem cell-engrafted NSG-HLA-DQ8 transgenic mice, we provide direct evidence for human autoantigen-specific Foxp3+Treg-induction in vivo. We identify HLA-DQ8-restricted insulin-specific CD4+T cells and demonstrate efficient human insulin-specific Foxp3+Treg-induction upon subimmunogenic vaccination with strong agonistic insulin mimetopes in vivo. Induced human Tregs are stable, show increased expression of Treg signature genes such as Foxp3, CTLA4, IL-2Rα and TIGIT and can efficiently suppress effector T cells. Such Foxp3+Treg-induction does not trigger any effector T cells. These T1D vaccine candidates could therefore represent an expedient improvement in the challenge to induce human Foxp3+Tregs and to develop novel precision medicines for prevention of islet autoimmunity in children at risk of T1D. PMID:26975663

TUNING IMMUNE TOLERANCE WITH VASOACTIVE INTESTINAL PEPTIDE: A NEW THERAPEUTIC APPROACH FOR IMMUNE DISORDERS

PubMed Central

POZO, DAVID; GONZALEZ-REY, ELENA; CHORNY, ALEJO; ANDERSON, PER; VARELA, NIEVES; DELGADO, MARIO

2007-01-01

The induction of immune tolerance is essential for the maintenance of immune homeostasis and to limit the occurrence of exacerbated inflammatory and autoimmune conditions. Multiple mechanisms act together to ensure self-tolerance, including central clonal deletion, cytokine deviation and induction of regulatory T cells. Identifying the factors that regulate these processes is crucial for the development of new therapies of autoimmune diseases and transplantation. The vasoactive intestinal peptide (VIP) is a well-characterized endogenous anti-inflammatory neuropeptide with therapeutic potential for a variety of immune disorders. Here we examine the latest research findings, which indicate that VIP participates in maintaining immune tolerance in two distinct ways: by regulating the balance between pro-inflammatory and anti-inflammatory factors, and by inducing the emergence of regulatory T cells with suppressive activity against autoreactive T-cell effectors. PMID:17521775

SMAD4 is Involved in the Development of Endotoxin Tolerance in Microglia.

PubMed

Liu, Xiaorong; Qin, Yongwei; Dai, Aihua; Zhang, Yu; Xue, Huaqing; Ni, Haidan; Han, Lijian; Zhu, Liang; Yuan, Debin; Tao, Tao; Cao, Maohong

2016-07-01

Initial exposure of macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Smad4 plays important roles in the induction of LPS tolerance. However, the function of Smad4 in microglia remains unknown. Here we show that expression of Smad4 was highly up-regulated in LPS-tolerized mouse cerebral cortex. Smad4 was mostly colocalized with microglia, rarely with neurons. Using a microglia cell line, BV2, we find that LPS activates endogenous Smad4, inducing its migration into the nucleus and increasing its expression. Smad4 significantly suppressed TLR-triggered production of proinflammatory cytokines (IL-6), increased anti-inflammatory cytokine in LPS-tolerized microglia. Moreover, IL-6 concentrations in culture supernatants after second LPS challenge are higher in SMAD4 small interfering RNA (siRNA) BV2 cells than control siRNA BV2 cells, indicating failure to induce tolerance in absence of Smad4 signaling. In our study, we conclude that both in vivo and in vitro, Smad4 signaling is required for maximal induction of endotoxin tolerance.

Recent thymic emigrants are tolerized in the absence of inflammation

PubMed Central

Friesen, Travis J.; Ji, Qingyong

2016-01-01

T cell development requires a period of postthymic maturation. Why this is the case has remained a mystery, particularly given the rigors of intrathymic developmental checkpoints, successfully traversed by only ∼5% of thymocytes. We now show that the first few weeks of T cell residence in the lymphoid periphery define a period of heightened susceptibility to tolerance induction to tissue-restricted antigens (TRAs), the outcome of which depends on the context in which recent thymic emigrants (RTEs) encounter antigen. After encounter with TRAs in the absence of inflammation, RTEs exhibited defects in proliferation, diminished cytokine production, elevated expression of anergy-associated genes, and diminished diabetogenicity. These properties were mirrored in vitro by enhanced RTE susceptibility to regulatory T cell–mediated suppression. In the presence of inflammation, RTEs and mature T cells were, in contrast, equally capable of inducing diabetes, proliferating, and producing cytokines. Thus, recirculating RTEs encounter TRAs during a transitional developmental stage that facilitates tolerance induction, but inflammation converts antigen-exposed, tolerance-prone RTEs into competent effector cells. PMID:27139493

T-cell receptor revision: friend or foe?

PubMed Central

Hale, J Scott; Fink, Pamela J

2010-01-01

T-cell receptor (TCR) revision is a process of tolerance induction by which peripheral T cells lose surface expression of an autoreactive TCR, reinduce expression of the recombinase machinery, rearrange genes encoding extrathymically generated TCRs for antigen, and express these new receptors on the cell surface. We discuss the evidence for this controversial tolerance mechanism below. Despite the apparent heresy of post-thymic gene rearrangement, we argue here that TCR revision follows the rules obeyed by maturing thymocytes undergoing gene recombination. Expression of the recombinase is carefully controlled both spatially and temporally, and may be initiated by loss of signals through surface TCRs. The resulting TCR repertoire is characterized by its diversity, self major histocompatibility complex restriction, self tolerance, and ability to mount productive immune responses specific for foreign antigens. Hence, TCR revision is a carefully regulated process of tolerance induction that can contribute to the protection of the individual against invading pathogens while preserving the integrity of self tissue. PMID:20201984

Antigen-Conjugated Human IgE Induces Antigen-Specific T Cell Tolerance in a Humanized Mouse Model

PubMed Central

Baravalle, Günther; Greer, Alexandra M.; LaFlam, Taylor N.; Shin, Jeoung-Sook

2015-01-01

Dendritic cells (DCs) play an important role in immune homeostasis through their ability to present Ags at steady state and mediate T cell tolerance. This characteristic renders DCs an attractive therapeutic target for the induction of tolerance against auto-antigens or allergens. Accordingly, Ag-conjugated DC–specific Abs have been proposed to be an excellent vehicle to deliver Ags to DCs for presentation and tolerance induction. However, this approach requires laborious reagent generation procedures and entails unpredictable side effects resulting from Ab-induced crosslinking of DC surface molecules. In this study, we examined whether IgE, a high-affinity, non–cross-linking natural ligand of FcεRI, could be used to target Ags to DCs and to induce Ag-specific T cell tolerance. We found that Ag-conjugated human IgE Fc domain (Fcε) effectively delivered Ags to DCs and enhanced Ag presentation by 1000- to 2500-fold in human FcεRIα-transgenic mice. Importantly, this presentation resulted in a systemic deletion of Ag-specific T cells and prevented these mice from developing delayed-type hypersensitivity, which is critically dependent on Ag-specific T cell immunity. Thus, targeting FcεRI on DCs via Ag-Fcε fusion protein may serve an alternative method to induce Ag-specific T cell tolerance in humans. PMID:24610015

Immunotherapy with myeloid cells for tolerance induction

PubMed Central

Rodriguez-García, Mercedes; Boros, Peter; Bromberg, Jonathan S.; Ochando, Jordi C.

2013-01-01

Purpose of review Understanding the interplay between myeloid dendritic cells and T cells under tolerogenic conditions, and whether their interactions induce the development of antigen-specific regulatory T cells (Tregs) is critical to uncover the mechanisms involved in the induction of indefinite allograft survival. Recent findings Myeloid dendritic cell–T-cell interactions are seminal events that determine the outcome of the immune response, and multiple in-vitro protocols suggest the generation of tolerogenic myeloid dendritic cells that modulate T-cell responses, and determine the outcome of the immune response to an allograft following adoptive transfer. We believe that identifying specific conditions that lead to the generation of tolerogenic myeloid dendritic cells and Tregs are critical for the manipulation the immune response towards the development of transplantation tolerance. Summary We summarize recent findings regarding specific culture conditions that generate tolerogenic myeloid dendritic cells that induce T-cell hyporesponsiveness and Treg development, and represents a novel immunotherapeutic approach to promote the induction of indefinite graft survival prolongation. The interpretations presented here illustrate that different mechanisms govern the generation tolerogenic myeloid dendritic cells, and we discuss the concomitant therapeutic implications. PMID:20616727

Recent thymic emigrants are tolerized in the absence of inflammation.

PubMed

Friesen, Travis J; Ji, Qingyong; Fink, Pamela J

2016-05-30

T cell development requires a period of postthymic maturation. Why this is the case has remained a mystery, particularly given the rigors of intrathymic developmental checkpoints, successfully traversed by only ∼5% of thymocytes. We now show that the first few weeks of T cell residence in the lymphoid periphery define a period of heightened susceptibility to tolerance induction to tissue-restricted antigens (TRAs), the outcome of which depends on the context in which recent thymic emigrants (RTEs) encounter antigen. After encounter with TRAs in the absence of inflammation, RTEs exhibited defects in proliferation, diminished cytokine production, elevated expression of anergy-associated genes, and diminished diabetogenicity. These properties were mirrored in vitro by enhanced RTE susceptibility to regulatory T cell-mediated suppression. In the presence of inflammation, RTEs and mature T cells were, in contrast, equally capable of inducing diabetes, proliferating, and producing cytokines. Thus, recirculating RTEs encounter TRAs during a transitional developmental stage that facilitates tolerance induction, but inflammation converts antigen-exposed, tolerance-prone RTEs into competent effector cells. © 2016 Friesen et al.

Role of Abscisic Acid in the Induction of Freezing Tolerance in Brassica napus Suspension-Cultured Cells 1

PubMed Central

Johnson-Flanagan, Anne M.; Huiwen, Zhong; Thiagarajah, Mohan R.; Saini, Hargurdeep S.

1991-01-01

Brassica napus suspension-cultured cells could be hardened in 6 days at 25°C by the addition of mefluidide or ABA to the culture medium. Cells treated with mefluidide (10 milligrams per liter) or ABA (50 micromolar) attained an LT50 of −17.5°C or −18°C, respectively, while the LT50 for the comparable nonhardened control (sucrose) was −10°C. The increased freezing tolerance of mefluidide-treated cells was paralleled by a 4- to 23-fold increase in ABA, as measured by gas-liquid chromatography using electron capture detection. Application of 1 milligram per liter of fluridone, an inhibitor of abscisic acid biosynthesis, prevented the mefluidide-induced increase in freezing tolerance and the accumulation of ABA. Both these inhibitory effects of fluridone were overridden by 50 micromolar ABA in the culture medium. On the basis of these results, we concluded that increased ABA levels are important for the induction of freezing tolerance in suspension-cultured cells. PMID:16668089

Heme oxygenase-1, carbon monoxide, and bilirubin induce tolerance in recipients toward islet allografts by modulating T regulatory cells.

PubMed

Lee, Soo Sun; Gao, Wenda; Mazzola, Silvia; Thomas, Michael N; Csizmadia, Eva; Otterbein, Leo E; Bach, Fritz H; Wang, Hongjun

2007-11-01

Heme oxygenase-1 (HO-1) induction in, or carbon monoxide (CO), or bilirubin administration to, donors and/or recipients frequently lead to long-term survival (>100 days) of DBA/2 islets into B6AF1 recipients. We tested here whether similar treatments show value in a stronger immunogenetic combination, i.e., BALB/c to C57BL/6, and attempted to elucidate the mechanism accounting for tolerance. Induction of HO-1, administering CO or bilirubin to the donor, the islets or the recipient, prolonged islet allograft survival to different extents. Combining all the above treatments (the "combined" protocol) led to survival for >100 days and antigen-specific tolerance to 60% of the transplanted grafts. A high level of forkhead box P3 (Foxp3) and transforming growth factor beta (TGF-beta) expression was detected in the long-term surviving grafts. With the combined protocol, significantly more T regulatory cells (Tregs) were observed surrounding islets 7 days following transplantation. No prolongation of graft survival was observed using the combined protocol when CD4+ CD25+ T cells were predepleted from the recipients before transplantation. In conclusion, our combined protocol led to long-term survival and tolerance to islets in the BALB/c to C57BL/6 combination by promoting Foxp3+ Tregs; these cells played a critical role in the induction and maintenance of tolerance in the recipient.

Breast milk immune complexes are potent inducers of oral tolerance in neonates and prevent asthma development.

PubMed

Mosconi, E; Rekima, A; Seitz-Polski, B; Kanda, A; Fleury, S; Tissandie, E; Monteiro, R; Dombrowicz, D D; Julia, V; Glaichenhaus, N; Verhasselt, V

2010-09-01

Allergic asthma is a chronic lung disease resulting from an inappropriate T helper (Th)-2 response to environmental antigens. Early tolerance induction is an attractive approach for primary prevention of asthma. Here, we found that breastfeeding by antigen-sensitized mothers exposed to antigen aerosols during lactation induced a robust and long-lasting antigen-specific protection from asthma. Protection was more profound and persistent than the one induced by antigen-exposed non-sensitized mothers. Milk from antigen-exposed sensitized mothers contained antigen-immunoglobulin (Ig) G immune complexes that were transferred to the newborn through the neonatal Fc receptor resulting in the induction of antigen-specific FoxP3(+) CD25(+) regulatory T cells. The induction of oral tolerance by milk immune complexes did not require the presence of transforming growth factor-beta in milk in contrast to tolerance induced by milk-borne free antigen. Furthermore, neither the presence of IgA in milk nor the expression of the inhibitory FcgammaRIIb in the newborn was required for tolerance induction. This study provides new insights on the mechanisms of tolerance induction in neonates and highlights that IgG immune complexes found in breast milk are potent inducers of oral tolerance. These observations may pave the way for the identification of key factors for primary prevention of immune-mediated diseases such as asthma.

Involvement of dendritic cells in allograft rejection new implications of dendritic cell-endothelial cell interactions.

PubMed

Schlichting, C L; Schareck, W D; Kofler, S; Weis, M

2007-04-01

For almost half a century immunologists have tried to tear down the MHC barrier, which separates two unrelated individuals during transplantation. Latest experimental data suggest that a breakthrough in vitro is imminent. Dendritic cells (DCs), which activate naïve allo-reactive T-cells (TCs), play a central role in the establishment of allo-antigen-specific immunity. Allograft solid organ rejection is initiated at the foreign endothelial cell (EC) layer, which forms an immunogenic barrier for migrating DCs. Thus, DC/EC interactions might play a crucial role in antigen-specific allograft rejection. Organ rejection is mediated by host allo-reactive TCs, which are activated by donor DCs (direct activation) or host DCs (indirect activation). Direct allo-antigen presentation by regulatory dendritic cells (DCreg) can play an instructive role towards tolerance induction. Several groups established that, DCregs, if transplanted beforehand, enter host thymus, spleen, or bone marrow where they might eventually establish allo-antigen-specific tolerance. A fundamental aspect of DC function is migration throughout the entire organism. After solid organ transplantation, host DCs bind to ECs, invade allograft tissues, and finally transmigrate into lymphoid vessels and secondary lymphoid organs, where they present allo-antigens to naïve host TCs. Recent data suggest that in vitro manipulated DCregs may mediate allo-transplantation tolerance induction. However, the fundamental mechanisms on how such DCregs cause host TCs in the periphery towards tolerance remain unclear. One very promising experimental concept is the simultaneous manipulation of DC direct and indirect TC activation/suppression, towards donor antigen-specific allo-transplantation tolerance. The allo-antigen-specific long-term tolerance induction mediated by DCreg pre-transplantation (with simultaneous short-term immunosuppression) has become reproducible in the laboratory animal setting. Despite the shortcomings of laboratory animal studies, strong promises are deriving from these studies for clinical kidney, heart, and liver transplantation.

Identification of Regulatory T Cells in Tolerated Allografts

PubMed Central

Graca, Luis; Cobbold, Stephen P.; Waldmann, Herman

2002-01-01

Induction of transplantation tolerance with certain therapeutic nondepleting monoclonal antibodies can lead to a robust state of peripheral “dominant” tolerance. Regulatory CD4+ T cells, which mediate this form of “dominant” tolerance, can be isolated from spleens of tolerant animals. To determine whether there were any extra-lymphoid sites that might harbor regulatory T cells we sought their presence in tolerated skin allografts and in normal skin. When tolerated skin grafts are retransplanted onto T cell–depleted hosts, graft-infiltrating T cells exit the graft and recolonize the new host. These colonizing T cells can be shown to contain members with regulatory function, as they can prevent nontolerant lymphocytes from rejecting fresh skin allografts, without hindrance of rejection of third party skin. Our results suggest that T cell suppression of graft rejection is an active process that operates beyond secondary lymphoid tissue, and involves the persistent presence of regulatory T cells at the site of the tolerated transplant. PMID:12070291

Modulation of liver tolerance by conventional and nonconventional antigen-presenting cells and regulatory immune cells

PubMed Central

Horst, Andrea Kristina; Neumann, Katrin; Diehl, Linda; Tiegs, Gisa

2016-01-01

The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the “liver tolerance effect”. Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells (APCs), which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process. PMID:27041638

Alloreactive Regulatory T Cells Allow the Generation of Mixed Chimerism and Transplant Tolerance.

PubMed

Ruiz, Paulina; Maldonado, Paula; Hidalgo, Yessia; Sauma, Daniela; Rosemblatt, Mario; Bono, Maria Rosa

2015-01-01

The induction of donor-specific transplant tolerance is one of the main goals of modern immunology. Establishment of a mixed chimerism state in the transplant recipient has proven to be a suitable strategy for the induction of long-term allograft tolerance; however, current experimental recipient preconditioning protocols have many side effects, and are not feasible for use in future therapies. In order to improve the current mixed chimerism induction protocols, we developed a non-myeloablative bone-marrow transplant (NM-BMT) protocol using retinoic acid (RA)-induced alloantigen-specific Tregs, clinically available immunosuppressive drugs, and lower doses of irradiation. We demonstrate that RA-induced alloantigen-specific Tregs in addition to a NM-BMT protocol generates stable mixed chimerism and induces tolerance to allogeneic secondary skin allografts in mice. Therefore, the establishment of mixed chimerism through the use of donor-specific Tregs rather than non-specific immunosuppression could have a potential use in organ transplantation.

Induction of neonatal tolerance to GFP-labeled karyocytes in C57/B6 mice.

PubMed

Dovhyi, Roman; Pishel, Iryna; Butenko, Gennadij; Skivka, Larysa

2017-08-01

Green fluorescent protein is widely used in biological studies including parabiosis models for visualization of cellular structures and cells. However, the growing number of the data is available regarding immunogenicity of this protein, which can interfere with its use in in vivo experiments. In this study, we attempted to induce neonatal immunological tolerance to GFP-labeled karyocytes by intraperitoneal injections of B6.GFP mouse splenocytes to newborn C57/B6 mice. GFP + skin graft integrity was evaluated under UV light at 6weeks after skin grafting. GFP + skin transplants survived up to 6weeks after grafting in all animals that undergone neonatal tolerance induction, whereas all skin grafts were rejected in control naïve mice within first two weeks. Thus, current protocol is suitable for induction of immune tolerance against GFP-labeled karyocytes. Copyright © 2017 Elsevier B.V. All rights reserved.

BIOMARKERS OF OPERATIONAL TOLERANCE IN SOLID ORGAN TRANSPLANTATION

PubMed Central

Heidt, Sebastiaan; Wood, Kathryn J.

2012-01-01

Introduction Long-term immunosuppressive therapy represents a huge burden on transplant recipients, but currently cannot be omitted. Improving long-term transplant outcome by immunosuppressive drug withdrawal may be achieved in patients who have developed (partial) immunological unresponsiveness towards their graft, either spontaneously or through tolerance induction. Reliable biomarkers are essential to define such immunological unresponsiveness and will facilitate controlled immunosuppressive drug weaning as well as provide surrogate end-points for tolerance induction trials. Areas covered Tolerance biomarkers have been defined for both liver and kidney transplantation and can accurately identify operationally tolerant transplant recipients retrospectively. These two tolerance fingerprints are remarkably different, indicating the involvement of distinct mechanisms. Limited data suggest that tolerance biomarkers can be detected in immunosuppressed transplant recipients. Whether these patients can safely have their immunosuppressive drugs withdrawn needs to be established. Expert opinion Mechanistic interpretation of the kidney transplant tolerance biomarker profile dominated by B cell markers remains a challenge in light of experimental evidence suggesting the pivotal involvement of regulatory T cells. Therefore, defining animal models that resemble human transplant tolerance is crucial in understanding the underlying mechanisms. Additionally, to ensure patient safety while monitoring for tolerance, it is essential to develop biomarkers to non-invasively detect early signs of rejection as well. PMID:22988481

Foxp3 Expression is Required for the Induction of Therapeutic Tissue Tolerance1

PubMed Central

Regateiro, Frederico S.; Chen, Ye; Kendal, Adrian R.; Hilbrands, Robert; Adams, Elizabeth; Cobbold, Stephen P.; Ma, Jianbo; Andersen, Kristian G.; Betz, Alexander G.; Zhang, Mindy; Madhiwalla, Shruti; Roberts, Bruce; Waldmann, Herman; Nolan, Kathleen F.; Howie, Duncan

2012-01-01

CD4+Foxp3+ Treg are essential for immune homeostasis and maintenance of self-tolerance. They are produced in the thymus and also generated de novo in the periphery in a TGFβ dependent manner. Foxp3+ Treg are also required to achieve tolerance to transplanted tissues when induced by co receptor or co stimulation blockade. Using TCR transgenic mice to avoid issues of autoimmune pathology, we show that Foxp3 expression is both necessary and sufficient for tissue tolerance by coreceptor blockade. Moreover, the known need in tolerance induction for TGFβ signalling to T cells can wholly be explained by its role in induction of Foxp3, as such signalling proved dispensable for the suppressive process. We analysed the relative contribution of TGFβ and Foxp3 to the transcriptome of TGFβ-induced Treg and showed that TGFβ elicited a large set of down-regulated signature genes. The number of genes uniquely modulated due to the influence of Foxp3 alone was surprisingly limited. Thus, despite the large genetic influence of TGFβ exposure on iTreg, the crucial Foxp3-influenced signature independent of TGFβ is small. Retroviral mediated conditional nuclear expression of Foxp3 proved sufficient to confer transplant-suppressive potency on CD4+ T cells, and was lost once nuclear Foxp3 expression was extinguished. These data support a dual role for TGFβ and Foxp3 in induced tolerance, where TGFβ stimulates Foxp3 expression, whose sustained expression is then associated with acquisition of tolerance. PMID:22988034

Increased Susceptibility to Allergic Asthma with the Impairment of Respiratory Tolerance Caused by Psychological Stress.

PubMed

Kawano, Tasuku; Ouchi, Ryusuke; Ishigaki, Takahiro; Masuda, Chiaki; Miyasaka, Tomomitsu; Ohkawara, Yuichi; Ohta, Nobuo; Takayanagi, Motoaki; Takahashi, Tomoko; Ohno, Isao

2018-06-06

Bronchial asthma is characterized by type 2 T helper (Th2) cell inflammation, essentially due to a breakdown of immune tolerance to harmless environmental allergens. Etiologically, experiences of psychological stress can be associated with a heightened prevalence of asthma. However, the mechanisms underlying stress-related asthma development are unclear. In this study, we examined whether psychological stress increases susceptibility to allergic asthma by downregulating immune tolerance. Female BALB/c mice were sensitized with ovalbumin/alum, followed by ovalbumin inhalation. Ovalbumin inhalation induced immune tolerance before sensitization occurred. Some mice were exposed to restraint stress during tolerance induction or sensitization. Asthma development was evaluated by airway responsiveness, inflammation, cytokine expression, and IgE synthesis. Sensitization was evaluated by measuring proliferation and cytokine production by splenocytes. The effects of stress exposure on the numbers and functions of dendritic cells and regulatory T (Treg) cells in bronchial lymph nodes and spleens were evaluated. To investigate the role of endogenous glucocorticoid in inhibiting immune tolerance after stress exposure, we examined the effects of (i) a glucocorticoid-receptor antagonist administered prior to stress exposure, and (ii) exogenous gluco-corticoid (instead of stress exposure). Asthmatic responses and Th2-biased sensitization, which were suppressed in tolerized mice, re-emerged in tolerized mice stressed during tolerance induction in association with decreased tolerogenic dendritic and Treg cell numbers. The effects of stress exposure on tolerized mice were abolished by administering a glucocorticoid-receptor antagonist and reproduced by administering exogenous glucocorticoid without stress. Our findings suggested that psychological stress can potentially increase allergic asthma susceptibility by inhibiting immune tolerance. © 2018 S. Karger AG, Basel.

Induction of cross-tolerance between protective effect of morphine and nicotine in 6-hydroxydopamine-induce neurotoxicity in SH-SY5Y human dopaminergic neuroblastoma cells.

PubMed

Elyasi, Leila; Eftekhar-Vaghefi, Seyed Hassan; Asadi-Shekaaria, Majid; Esmaeili-Mahani, Saeed

2018-06-27

Parkinson's disease is a progressive neurodegenerative disease characterized by progressive and selective death of dopaminergic neurons. It has been reported that nicotine and morphine have protective roles during neuronal damage in Parkinson's disease. In addition, the induction of cross-tolerance between their biological effects has been shown in numerous reports. Here, we investigated the effects of nicotine and morphine on 6-OHDA-induced neurotoxicity in human neuroblastoma SH-SY5Y cell line as an in vitro model of Parkinson's disease. Cell damage was induced by 150 μM 6-OHDA and the cells viability was examined by MTT assay. Intracellular reactive oxygen species, calcium level and mitochondrial membrane potential were determined by fluorescence spectrophotometer method. Biochemical markers of apoptosis were also evaluated by immunoblotting. The data showed that morphine and nicotine prevent 6-OHDA- induced cell damage and apoptosis. However, the protective effects of nicotine were not observed in chronic morphine-pretreated cells. Morphine had no protective effects in chronic nicotine-incubated cells. A cross-tolerance between protective effects of morphine and nicotine was occurred in 6-OHDA-induced SH-SY5Y cell toxicity.

Low cost industrial production of coagulation factor IX bioencapsulated in lettuce cells for oral tolerance induction in hemophilia B

PubMed Central

Su, Jin; Zhu, Liqing; Sherman, Alexandra; Wang, Xiaomei; Lin, Shina; Kamesh, Aditya; Norikane, Joey H.; Streatfield, Stephen J.; Herzog, Roland W.; Daniell, Henry

2015-01-01

Antibodies (inhibitors) developed by hemophilia B patients against coagulation factor IX (FIX) are challenging to eliminate because of anaphylaxis or nephrotic syndrome after continued infusion. To address this urgent unmet medical need, FIX fused with a transmucosal carrier (CTB) was produced in a commercial lettuce (Simpson Elite) cultivar using species specific chloroplast vectors regulated by endogenous psbA sequences. CTB-FIX (~1mg/g) in lyophilized cells was stable with proper folding, disulfide bonds and pentamer assembly when stored ~2 years at ambient temperature. Feeding lettuce cells to hemophilia B mice delivered CTB-FIX efficiently to the gut immune system, induced LAP+ regulatory T cells and suppressed inhibitor/IgE formation and anaphylaxis against FIX. Lyophilized cells enabled 10-fold dose escalation studies and successful induction of oral tolerance was observed in all tested doses. Induction of tolerance in such a broad dose range should enable oral delivery to patients of different age groups and diverse genetic background. Using Fraunhofer cGMP hydroponic system, ~870 kg fresh or 43.5 kg dry weight can be harvested per 1000 ft2 per annum yielding 24,000–36,000 doses for 20-kg pediatric patients, enabling first commercial development of an oral drug, addressing prohibitively expensive purification, cold storage/transportation and short shelf life of current protein drugs. PMID:26302233

Assessment of tolerance induction by Origanum vulgare L. essential oil or carvacrol in Pseudomonas aeruginosa cultivated in a meat-based broth and in a meat model.

PubMed

da Silva Luz, Isabelle; Gomes-Neto, Nelson Justino; Magnani, Marciane; de Souza, Evandro Leite

2015-12-01

This study assessed the efficacy of Origanum vulgare L. essential oil (OVEO) and carvacrol in inhibiting the growth of Pseudomonas aeruginosa ATCC 9027, as well as the development of direct tolerance and cross-tolerance when this bacterium was challenged with sublethal amounts of these substances in a meat-based broth and in a meat model. OVEO and carvacrol at their minimum inhibitory concentrations (MICs), 1/2 MIC and 1/4 MIC decreased the viable cell counts of P. aeruginosa in meat-based broth. Direct tolerance or cross-tolerance was not induced after exposure of the assayed bacterial strain to sublethal amounts of OVEO or carvacrol in meat-based broth and in an artificially contaminated ground beef. Bacterial cells progressively subcultured in meat-based broth with increasing amounts of the tested substances survived up to the MIC of OVEO and to 1/2 MIC of carvacrol. The results reveal a lack of induction of tolerance in P. aeruginosa by exposure to OVEO or carvacrol in meat-based broth and in a meat model. © The Author(s) 2014.

Longitudinal Studies of a B Cell Derived Signature of Tolerance in Renal Transplant Recipients

PubMed Central

Newell, Kenneth A.; Asare, Adam; Sanz, Ignacio; Wei, Chungwen; Rosenberg, Alexander; Gao, Zhong; Kanaparthi, Sai; Asare, Smita; Lim, Noha; Stahly, Michael; Howell, Michael; Knechtle, Stuart; Kirk, Allan; Marks, William H.; Kawai, Tatsuo; Spitzer, Thomas; Tolkoff-Rubin, Nina; Sykes, Megan; Sachs, David H.; Cosimi, A. Benedict; Burlingham, William J.; Phippard, Deborah; Turka, Laurence A.

2016-01-01

Biomarkers of transplant tolerance would enhance the safety and feasibility of clinical tolerance trials and potentially facilitate management of patients receiving immunosuppression. To this end, we examined blood from spontaneously tolerant renal transplant recipients and patients enrolled in two interventional tolerance trials using flow cytometry and gene expression profiling. Using a previously reported tolerant cohort as well as newly identified tolerant patients we confirmed our previous finding that tolerance was associated with increased expression of B cell-associated genes relative to immunosuppressed patients. This was not accounted for merely by an increase in total B cell numbers, but was associated with the increased frequencies of transitional and naïve B cells. Moreover, serial measurements of gene expression demonstrated that this pattern persisted over several years although patients receiving immunosuppression also displayed an increase in the two most dominant tolerance-related B cell genes, IGKV1D-13 and IGLL-1, over time. Importantly, patients rendered tolerant via induction of transient mixed chimerism, and those weaned to minimal immunosuppression, showed similar increases in IGKV1D-13 as did spontaneously tolerant individuals. Collectively, these findings support the notion that alterations in B cells may be a common theme for tolerant kidney transplant recipients, and a useful monitoring tool in prospective trials. PMID:26461968

PD-L1–Driven Tolerance Protects Neurogenin3-Induced Islet Neogenesis to Reverse Established Type 1 Diabetes in NOD Mice

PubMed Central

Li, Rongying; Lee, Jeongkyung; Kim, Mi-sun; Liu, Victoria; Moulik, Mousumi; Li, Haiyan; Yi, Qing; Xie, Aini; Chen, Wenhao; Yang, Lina; Li, Yimin; Tsai, Tsung Huang; Oka, Kazuhiro

2015-01-01

A breakdown in self-tolerance underlies autoimmune destruction of β-cells and type 1 diabetes. A cure by restoring β-cell mass is limited by the availability of transplantable β-cells and the need for chronic immunosuppression. Evidence indicates that inhibiting costimulation through the PD-1/PD-L1 pathway is central to immune tolerance. We therefore tested whether induction of islet neogenesis in the liver, protected by PD-L1–driven tolerance, reverses diabetes in NOD mice. We demonstrated a robust induction of neo-islets in the liver of diabetic NOD mice by gene transfer of Neurogenin3, the islet-defining factor, along with betacellulin, an islet growth factor. These neo-islets expressed all the major pancreatic hormones and transcription factors. However, an enduring restoration of glucose-stimulated insulin secretion and euglycemia occurs only when tolerance is also induced by the targeted overexpression of PD-L1 in the neo-islets, which results in inhibition of proliferation and increased apoptosis of infiltrating CD4+ T cells. Further analysis revealed an inhibition of cytokine production from lymphocytes isolated from the liver but not from the spleen of treated mice, indicating that treatment did not result in generalized immunosuppression. This treatment strategy leads to persistence of functional neo-islets that resist autoimmune destruction and consequently an enduring reversal of diabetes in NOD mice. PMID:25332429

Designer dendritic cells for tolerance induction: guided not misguided missiles.

PubMed

Hackstein, H; Morelli, A E; Thomson, A W

2001-08-01

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that play crucial roles as initiators and modulators of adaptive immune responses. Although DC-based vaccines have been utilized successfully to generate cytolytic T-cell activity against tumor antigens (Ags), evidence has accumulated that DCs also have potent capabilities to tolerize T cells in an Ag-specific manner. DCs cultured in the laboratory can suppress auto- or alloimmunity. Current and prospective strategies to promote this inherent tolerogenic potential of DCs might prove to be important for the therapy of transplant rejection and autoimmune diseases.

40 projects in stem cell research, tissue engineering, tolerance induction and more (NRP46 "Implants and Transplants" 1999-2006).

PubMed

Thiel, Gilbert T

2007-03-02

Forty projects on stem cell research, tissue and matrix engineering, tolerance induction and other topics were supported by the Swiss National Research Program NRP46 (Implants, Transplants) from 1999-2006. The last project is devoted to developing stem cell lines from frozen surplus human embryos in Switzerland, which would otherwise have to be destroyed at the end of 2008. It is entitled JESP (Joint Embryonic Stem Cell Project) since it involves two Swiss universities, in vitro fertilisation centres and experts from the humanities (ethics and law) to handle this difficult problem. Over the years, stem cell transplantation and tissue/matrix engineering have drawn closer to each other and even developed synergies. Progress in stem cell research has been slower than anticipated, but a multitude of technical skills (phenotyping, isolation, transfection, induction of differentiation, labelling, expanding cells in culture, etc) were acquired. Understanding of stem cell biology has grown. The 7 projects on tissue and matrix engineering progressed closer to clinical applicability than the stem cell projects. Of 3 projects to implant encapsulated cells for the production of hormones (insulin, erythropoietin), one is close to clinical pilot studies with an advanced encapsulated device. Five projects were devoted to mechanisms of tolerance or the role of metzincins in chronic allograft nephropathy. Four studies in psychology and communication in transplantation were funded, as were 5 projects in ethics, law and the history of transplantation in Switzerland. The goal of NRP46 was to provide an impulse for research in these new fields and bring together experts from the humanities, biology and medicine to cope more effectively with the problems of regenerative medicine in the future. The majority of goals were attained, mainly in the basics.

Antigen-specific tolerance inhibits autoimmune uveitis in pre-sensitized animals by deletion and CD4+CD25+ T-regulatory cells.

PubMed

Matta, Bharati; Jha, Purushottam; Bora, Puran S; Bora, Nalini S

2010-02-01

The objective of this study was to inhibit experimental autoimmune anterior uveitis (EAAU) by establishing antigen-specific immune tolerance in animals pre-sensitized with melanin-associated antigen (MAA). Intravenous administration of MAA on days 6, 7, 8 and 9 post-immunization induced tolerance and inhibited EAAU in all Lewis rats. The number of cells (total T cells, CD4(+) T cells and CD8(+) T cells) undergoing apoptosis dramatically increased in the popliteal lymph nodes (LNs) of the tolerized animals compared with non-tolerized animals. In addition, Fas ligand (FasL), TNF receptor 1 (TNFR1) and caspase-8 were upregulated in tolerized rats. Proliferation of total lymphocytes, CD4(+)T cells and CD8(+) T cells (harvested from the popliteal LNs) in response to antigenic stimulation was drastically reduced in the state of tolerance compared with the cells from non-tolerized animals. The level of interferon (IFN)-gamma and IL-2 decreased, whereas TGF-beta2 was elevated in the state of tolerance. Furthermore, the number of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) increased in the popliteal LNs of tolerized animals compared with non-tolerized animals. In conclusion, our results suggest that deletion of antigen-specific T cells by apoptosis and active suppression mediated by Tregs has an important role in the induction of antigen specific immune tolerance in animals with an established immune response against MAA.

Low cost industrial production of coagulation factor IX bioencapsulated in lettuce cells for oral tolerance induction in hemophilia B.

PubMed

Su, Jin; Zhu, Liqing; Sherman, Alexandra; Wang, Xiaomei; Lin, Shina; Kamesh, Aditya; Norikane, Joey H; Streatfield, Stephen J; Herzog, Roland W; Daniell, Henry

2015-11-01

Antibodies (inhibitors) developed by hemophilia B patients against coagulation factor IX (FIX) are challenging to eliminate because of anaphylaxis or nephrotic syndrome after continued infusion. To address this urgent unmet medical need, FIX fused with a transmucosal carrier (CTB) was produced in a commercial lettuce (Simpson Elite) cultivar using species specific chloroplast vectors regulated by endogenous psbA sequences. CTB-FIX (∼1 mg/g) in lyophilized cells was stable with proper folding, disulfide bonds and pentamer assembly when stored ∼2 years at ambient temperature. Feeding lettuce cells to hemophilia B mice delivered CTB-FIX efficiently to the gut immune system, induced LAP(+) regulatory T cells and suppressed inhibitor/IgE formation and anaphylaxis against FIX. Lyophilized cells enabled 10-fold dose escalation studies and successful induction of oral tolerance was observed in all tested doses. Induction of tolerance in such a broad dose range should enable oral delivery to patients of different age groups and diverse genetic background. Using Fraunhofer cGMP hydroponic system, ∼870 kg fresh or 43.5 kg dry weight can be harvested per 1000 ft(2) per annum yielding 24,000-36,000 doses for 20-kg pediatric patients, enabling first commercial development of an oral drug, addressing prohibitively expensive purification, cold storage/transportation and short shelf life of current protein drugs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The CD8 T-cell response during tolerance induction in liver transplantation

PubMed Central

Wong, Yik Chun; McCaughan, Geoffrey W; Bowen, David G; Bertolino, Patrick

2016-01-01

Both experimental and clinical studies have shown that the liver possesses unique tolerogenic properties. Liver allografts can be spontaneously accepted across complete major histocompatibility mismatch in some animal models. In addition, some liver transplant patients can be successfully withdrawn from immunosuppressive medications, developing ‘operational tolerance'. Multiple mechanisms have been shown to be involved in inducing and maintaining alloimmune tolerance associated with liver transplantation. Here, we focus on CD8 T-cell tolerance in this setting. We first discuss how alloreactive cytotoxic T-cell responses are generated against allografts, before reviewing how the liver parenchyma, donor passenger leucocytes and the host immune system function together to attenuate alloreactive CD8 T-cell responses to promote the long-term survival of liver transplants. PMID:27867515

Regulatory dendritic cells: there is more than just immune activation.

PubMed

Schmidt, Susanne V; Nino-Castro, Andrea C; Schultze, Joachim L

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34(+) stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies.

Regulatory dendritic cells: there is more than just immune activation

PubMed Central

Schmidt, Susanne V.; Nino-Castro, Andrea C.; Schultze, Joachim L.

2012-01-01

The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34+ stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies. PMID:22969767

Quantitative analysis of antigen for the induction of tolerance in carcinoembryonic antigen transgenic mice.

PubMed Central

Hasegawa, T; Isobe, K; Nakashima, I; Shimokata, K

1992-01-01

In order to analyse the amounts of antigen in the thymus for the induction of tolerance, several carcinoembryonic antigen (CEA) transgenic lines were established which expressed human CEA antigen with different amounts. The chimeric KSN nude mice transplanted with the thymus of the B601 line (in which CEA mRNA and CEA protein could be detected in various tissues) to kidney capsule showed tolerance to human CEA. On the other hand, the chimeric KSN nude mice transplanted with the thymus of the B602 or BC60 line (in which neither CEA mRNA nor CEA protein could be detected by Northern blot analysis and flow cytometry analysis) or normal C57BL/6 (B6) did not develop the tolerance to human CEA. However, the chimeric KSN nude mice transplanted simultaneously with thymus of the B6 and spleen of the B601 line became tolerant to human CEA antigen. In the case of systemic immunization with cells which had CEA antigen, the B601 line was tolerant to human CEA. Surprisingly, the B602 and BC60 lines were also tolerant to CEA molecule. These results indicate that not only the antigen present in the thymus but also the antigen which flows from the peripheral organs to the thymus may be necessary for the induction of CEA tolerance. Images Figure 1 PMID:1493931

IL-10 and IL-27 producing dendritic cells capable of enhancing IL-10 production of T cells are induced in oral tolerance.

PubMed

Shiokawa, Aya; Tanabe, Kosuke; Tsuji, Noriko M; Sato, Ryuichiro; Hachimura, Satoshi

2009-06-30

Oral tolerance is a key feature of intestinal immunity, generating systemic tolerance to ingested antigens (Ag). Dendritic cells (DC) have been revealed as important immune regulators, however, the precise role of DC in oral tolerance induction remains unclear. We investigated the characteristics of DC in spleen, mesenteric lymph node (MLN), and Peyer's patch (PP) after oral Ag administration in a TCR-transgenic mouse model. DC from PP and MLN of tolerized mice induced IL-10 production but not Foxp3 expression in cocultured T cells. IL-10 production was markedly increased after 5-7-day Ag administration especially in PP DC. On the other hand, IL-27 production was increased after 2-5-day Ag administration. CD11b(+) DC, which increased after ingestion of Ag, prominently expressed IL-10 and IL-27 compared with CD11b(-) DC. These results suggest that IL-10 and IL-27 producing DC are increased by interaction with antigen specific T cells in PP, and these DC act as an inducer of IL-10 producing T cells in oral tolerance.

Mucosal tolerance to experimental autoimmune myasthenia gravis is associated with down-regulation of AChR-specific IFN-gamma-expressing Th1-like cells and up-regulation of TGF-beta mRNA in mononuclear cells.

PubMed

Ma, C G; Zhang, G X; Xiao, B G; Wang, Z Y; Link, J; Olsson, T; Link, H

1996-02-13

Oral and nasal administration of nicotinic acetylcholine receptor (AChR) to Lewis rats prior to myasthenogenic immunization with AChR and complete Freund's adjuvant (CFA) resulted in prevention or marked decrease of the severity of experimental autoimmune myasthenia gravis (EAMG) and suppression of AChR-specific B-cell responses and of AChR-reactive T-cell function. To examine the involvement of immunoregulatory cytokines and the underlying mechanisms involved in tolerance induction, in situ hybridization with radiolabeled cDNA oligonucleotide proves was adopted to enumerate mononuclear cells (MNC) expressing mRNA for the proinflammatory cytokine interferon-gamma (IFN-gamma), the B cell-stimulating interleukin-4 (IL-4), and the immunosuppressive transforming growth factor-beta (TGF-beta). Popliteal and inguinal lymph nodes from EAMG rats contained elevated numbers of AChR-reactive IFN-gamma, IL-4, and TGF-beta mRNA-expressing cells, compared to control rats receiving PBS orally or nasally and injected with CFA only. Oral and nasal tolerance was accompanied by decreased numbers of AChR-reactive IFN-gamma and IL-4 mRNA-expressing cells and strong up-regulation of TGF-beta mRNA-positive cells in lymphoid organs when compared to nontolerized EAMG control rats. The results suggest that IFN-gamma and IL-4 are central effector molecules in the development of EAMG and that TGF-beta plays an important role in tolerance induction to EAMG.

Mesenteric lymph node stromal cell‐derived extracellular vesicles contribute to peripheral de novo induction of Foxp3+ regulatory T cells

PubMed Central

Pasztoi, Maria; Pezoldt, Joern; Beckstette, Michael; Lipps, Christoph; Wirth, Dagmar; Rohde, Manfred; Paloczi, Krisztina; Buzas, Edit Iren

2017-01-01

Abstract Intestinal regulatory T cells (Tregs) are fundamental in peripheral tolerance toward commensals and food‐borne antigens. Accordingly, gut‐draining mesenteric lymph nodes (mLNs) represent a site of efficient peripheral de novo Treg induction when compared to skin‐draining peripheral LNs (pLNs), and we had recently shown that LN stromal cells substantially contribute to this process. Here, we aimed to unravel the underlying molecular mechanisms and generated immortalized fibroblastic reticular cell lines (iFRCs) from mLNs and pLNs, allowing unlimited investigation of this rare stromal cell subset. In line with our previous findings, mLN‐iFRCs showed a higher Treg‐inducing capacity when compared to pLN‐iFRCs. RNA‐seq analysis focusing on secreted molecules revealed a more tolerogenic phenotype of mLN‐ as compared to pLN‐iFRCs. Remarkably, mLN‐iFRCs produced substantial numbers of microvesicles (MVs) that carried elevated levels of TGF‐β when compared to pLN‐iFRC‐derived MVs, and these novel players of intercellular communication were shown to be responsible for the tolerogenic properties of mLN‐iFRCs. Thus, stromal cells originating from mLNs contribute to peripheral tolerance by fostering de novo Treg induction using TGF‐β‐carrying MVs. This finding provides novel insights into the subcellular/molecular mechanisms of de novo Treg induction and might serve as promising tool for future therapeutic applications to treat inflammatory disorders. PMID:28833065

Postdoctoral Fellow | Center for Cancer Research

Cancer.gov

Seeking highly motivated postdoctoral fellows to study the biology of graft-versus-host disease and mechanisms of its prevention and tolerance induction after allogeneic hematopoietic cell transplantation.

Persistence of antigen is required to maintain transplantation tolerance induced by genetic modification of bone marrow stem cells.

PubMed

Tian, C; Bagley, J; Iacomini, J

2006-09-01

Genetic modification of hematopoietic stem cells (HSCs) resulting in a state of molecular chimerism can be used to induce donor-specific tolerance to allografts. However, the requirements for maintaining tolerance in molecular chimeras remain unknown. Here, we examined whether long-term expression of a retrovirally encoded alloantigen in hematopoietic cells is required to maintain donor-specific tolerance in molecular chimeras. To this end, mice were reconstituted with syngeneic bone marrow transduced with retroviruses carrying the gene encoding the allogeneic MHC class I molecule Kb. Following induction of molecular chimerism, mice were depleted of cells expressing Kb by administration of the anti-Kb monoclonal antibody Y-3. Mice that were effectively depleted of cells expressing the retrovirally encoded MHC class I antigen rejected Kb disparate skin allografts. In contrast, control molecular chimeras accepted Kb disparate skin allografts indefinitely. These data suggest maintenance of tolerance in molecular chimeras requires long-term expression of retrovirally transduced alloantigen on the progeny of retrovirally transduced HSCs.

Spaceflight impairs antigen-specific tolerance induction in vivo and increases inflammatory cytokines.

PubMed

Chang, Tammy T; Spurlock, Sandra M; Candelario, Tara Lynne T; Grenon, S Marlene; Hughes-Fulford, Millie

2015-10-01

The health risks of a dysregulated immune response during spaceflight are important to understand as plans emerge for humans to embark on long-term space travel to Mars. In this first-of-its-kind study, we used adoptive transfer of T-cell receptor transgenic OT-II CD4 T cells to track an in vivo antigen-specific immune response that was induced during the course of spaceflight. Experimental mice destined for spaceflight and mice that remained on the ground received transferred OT-II cells and cognate peptide stimulation with ovalbumin (OVA) 323-339 plus the inflammatory adjuvant, monophosphoryl lipid A. Control mice in both flight and ground cohorts received monophosphoryl lipid A alone without additional OVA stimulation. Numbers of OT-II cells in flight mice treated with OVA were significantly increased by 2-fold compared with ground mice treated with OVA, suggesting that tolerance induction was impaired by spaceflight. Production of proinflammatory cytokines were significantly increased in flight compared with ground mice, including a 5-fold increase in IFN-γ and a 10-fold increase in IL-17. This study is the first to show that immune tolerance may be impaired in spaceflight, leading to excessive inflammatory responses. © FASEB.

Lymphocytes from orally tolerized mice display enhanced susceptibility to death by apoptosis when cultured in the absence of antigen in vitro.

PubMed Central

Garside, P.; Steel, M.; Worthey, E. A.; Kewin, P. J.; Howie, S. E.; Harrison, D. J.; Bishop, D.; Mowat, A. M.

1996-01-01

The mechanism responsible for the induction of immunological tolerance by oral administration of soluble antigen remains unclear. Here we show that, when cultured in vitro in the absence of antigen, lymphocytes from mice tolerized with a single feed of 25 mg of ovalbumin display an enhanced mortality in comparison with cells from immunized control animals. This increased cell death affects both CD4+ and CD8+ T-lymphocyte subsets, and morphological and flow cytometric analyses suggest that it occurs via apoptosis. All of the changes associated with the propensity of tolerant cells to die by apoptosis in vitro are reduced by the inclusion of the tolerizing antigen in the cultures. These results suggest that tolerance to dietary proteins is accompanied by functional changes in T lymphocytes that render them susceptible to apoptosis. This mechanism may underlie the profound and permanent tolerance to food antigens found under physiological conditions and may provide a useful basis for immunotherapy. Images Figure 3 PMID:8952532

Roles of lymphatic endothelial cells expressing peripheral tissue antigens in CD4 T-cell tolerance induction.

PubMed

Rouhani, Sherin J; Eccles, Jacob D; Riccardi, Priscila; Peske, J David; Tewalt, Eric F; Cohen, Jarish N; Liblau, Roland; Mäkinen, Taija; Engelhard, Victor H

2015-04-10

Lymphatic endothelial cells (LECs) directly express peripheral tissue antigens and induce CD8 T-cell deletional tolerance. LECs express MHC-II molecules, suggesting they might also tolerize CD4 T cells. We demonstrate that when β-galactosidase (β-gal) is expressed in LECs, β-gal-specific CD8 T cells undergo deletion via the PD-1/PD-L1 and LAG-3/MHC-II pathways. In contrast, LECs do not present endogenous β-gal in the context of MHC-II molecules to β-gal-specific CD4 T cells. Lack of presentation is independent of antigen localization, as membrane-bound haemagglutinin and I-Eα are also not presented by MHC-II molecules. LECs express invariant chain and cathepsin L, but not H2-M, suggesting that they cannot load endogenous antigenic peptides onto MHC-II molecules. Importantly, LECs transfer β-gal to dendritic cells, which subsequently present it to induce CD4 T-cell anergy. Therefore, LECs serve as an antigen reservoir for CD4 T-cell tolerance, and MHC-II molecules on LECs are used to induce CD8 T-cell tolerance via LAG-3.

Roles of lymphatic endothelial cells expressing peripheral tissue antigens in CD4 T-cell tolerance induction

PubMed Central

Rouhani, Sherin J.; Eccles, Jacob D.; Riccardi, Priscila; Peske, J. David; Tewalt, Eric F.; Cohen, Jarish N.; Liblau, Roland; Mäkinen, Taija; Engelhard, Victor H.

2015-01-01

Lymphatic endothelial cells (LECs) directly express peripheral tissue antigens and induce CD8 T-cell deletional tolerance. LECs express MHC-II molecules, suggesting they might also tolerize CD4 T cells. We demonstrate that when β-galactosidase (β-gal) is expressed in LECs, β-gal-specific CD8 T cells undergo deletion via the PD-1/PD-L1 and LAG-3/MHC-II pathways. In contrast, LECs do not present endogenous β-gal in the context of MHC-II molecules to β-gal-specific CD4 T cells. Lack of presentation is independent of antigen localization, as membrane-bound haemagglutinin and I-Eα are also not presented by MHC-II molecules. LECs express invariant chain and cathepsin L, but not H2-M, suggesting that they cannot load endogenous antigenic peptides onto MHC-II molecules. Importantly, LECs transfer β-gal to dendritic cells, which subsequently present it to induce CD4 T-cell anergy. Therefore, LECs serve as an antigen reservoir for CD4 T-cell tolerance, and MHC-II molecules on LECs are used to induce CD8 T-cell tolerance via LAG-3. PMID:25857745

Tolerance of Erythrocytes in Poultry: Induction and Specificity

PubMed Central

Mitchison, N. A.

1962-01-01

Measurement of the rate of elimination of 51Cr-labelled erythrocytes provides a reliable test of immunity in fowls. Chickens can be rendered tolerant of homologous and turkey erythrocytes, as judged by this test, by receiving a series of transfusions of irradiated blood. The series were arranged so that foreign cells remained present in the circulation from the time of hatching. Tolerance induced by this treatment is generally incomplete, but can last indefinitely. In some chickens the manifestation of tolerance of turkey erythrocytes is delayed, probably because of passive transmission of antibody from the dam. Chickens old enough to react against small transfusions of homologous blood can still be rendered tolerant by massive transfusions. Tolerance of the erythrocytes from an individual donor extends only slightly to those from other donors. Tolerance acquired in this way, through transfusion of irradiated blood, stands in contrast to the more stable and complete tolerance that can be acquired through administration of viable cells. Viable cells, on the other hand, provide a less sensitive test, for birds which tolerate skin homografts often eliminate rapidly erythrocytes from the same donor. PMID:14474652

Hydroxyurea therapy requires HbF induction for clinical benefit in a sickle cell mouse model

PubMed Central

Lebensburger, Jeffrey D.; Pestina, Tamara I.; Ware, Russell E.; Boyd, Kelli L.; Persons, Derek A.

2010-01-01

Hydroxyurea has proven clinical efficacy in patients with sickle cell disease. Potential mechanisms for the beneficial effects include fetal hemoglobin induction and the reduction of cell adhesive properties, inflammation and hypercoagulability. Using a murine model of sickle cell disease in which fetal hemoglobin induction does not occur, we evaluated whether hydroxyurea administration would still yield improvements in hematologic parameters and reduce end-organ damage. Animals given a maximally tolerated dose of hydroxyurea that resulted in significant reductions in the neutrophil and platelet counts showed no improvement in hemolytic anemia and end-organ damage compared to control mice. In contrast, animals having high levels of fetal hemoglobin due to gene transfer with a γ-globin lentiviral vector showed correction of anemia and organ damage. These data suggest that induction of fetal hemoglobin by hydroxyurea is an essential mechanism for its clinical benefits. PMID:20378564

Animal models of allergen-induced tolerance in asthma: are T-regulatory-1 cells (Tr-1) the solution for T-helper-2 cells (Th-2) in asthma?

PubMed

Tournoy, K G; Hove, C; Grooten, J; Moerloose, K; Brusselle, G G; Joos, G F

2006-01-01

Non-specific anti-inflammatory medication is actually the treatment of choice for controlling the T-helper type 2 (Th-2) cell-driven airway inflammation in asthma. The induction of counterbalancing Th-1 cell clones, long considered a promising approach for immunotherapy, has failed to fulfil its promise because of potentially detrimental side-effects. This is therefore probably not a valid option for the treatment of asthma. With the increasing awareness that active immune mechanisms exist to control inflammatory responses, interest rises to investigate whether these can be exploited to control allergen-induced airway disease. The induction of antigen-specific T cells with suppressive characteristics (regulatory T cells) is therefore a potentially interesting approach. These regulatory T cells mediate tolerance in healthy, non-atopic individuals and have the potential of becoming an effective means of preventing allergen-induced airway inflammation and possibly of suppressing ongoing allergic immune responses. Here we review the available knowledge about allergen-induced suppressive immunity obtained from animal models taking into account the different developmental stages of allergic airway disease.

High levels of the Mps1 checkpoint protein are protective of aneuploidy in breast cancer cells

PubMed Central

Daniel, Jewel; Coulter, Jonathan; Woo, Ju-Hyung; Wilsbach, Kathleen; Gabrielson, Edward

2011-01-01

Most human cancers are aneuploid and have chromosomal instability, which contrasts to the inability of human cells to normally tolerate aneuploidy. Noting that aneuploidy in human breast cancer correlates with increased expression levels of the Mps1 checkpoint gene, we investigated whether these high levels of Mps1 contribute to the ability of breast cancer cells to tolerate this aneuploidy. Reducing Mps1 levels in cultured human breast cancer cells by RNAi resulted in aberrant mitoses, induction of apoptosis, and decreased ability of human breast cancer cells to grow as xenografts in nude mice. Remarkably, breast cancer cells that survive reductions in levels of Mps1 have relatively less aneuploidy, as measured by copies of specific chromosomes, compared with cells that have constitutively high levels of Mps1. Thus, high levels of Mps1 in breast cancer cells likely contribute to these cells tolerating aneuploidy. PMID:21402910

High levels of the Mps1 checkpoint protein are protective of aneuploidy in breast cancer cells.

PubMed

Daniel, Jewel; Coulter, Jonathan; Woo, Ju-Hyung; Wilsbach, Kathleen; Gabrielson, Edward

2011-03-29

Most human cancers are aneuploid and have chromosomal instability, which contrasts to the inability of human cells to normally tolerate aneuploidy. Noting that aneuploidy in human breast cancer correlates with increased expression levels of the Mps1 checkpoint gene, we investigated whether these high levels of Mps1 contribute to the ability of breast cancer cells to tolerate this aneuploidy. Reducing Mps1 levels in cultured human breast cancer cells by RNAi resulted in aberrant mitoses, induction of apoptosis, and decreased ability of human breast cancer cells to grow as xenografts in nude mice. Remarkably, breast cancer cells that survive reductions in levels of Mps1 have relatively less aneuploidy, as measured by copies of specific chromosomes, compared with cells that have constitutively high levels of Mps1. Thus, high levels of Mps1 in breast cancer cells likely contribute to these cells tolerating aneuploidy.

Induction of endoplasmic reticulum stress under endotoxin tolerance increases inflammatory responses and decreases Pseudomonas aeruginosa pneumonia.

PubMed

Kim, Sena; Joe, Yeonsoo; Park, Se-Ung; Jeong, Sun Oh; Kim, Jin-Kyung; Park, Seong Hoon; Pae, Hyun-Ock; Surh, Young-Joon; Shin, Jaekyoon; Chung, Hun Taeg

2018-06-20

Endotoxin tolerance develops in the late phase of sepsis to protect cells from an early hyperinflammatory response. Nonetheless, because it induces an immunosuppressive environment, patients with sepsis in its late phase are affected by secondary infections, particularly bacterial pneumonia. Here, we showed that induction of endoplasmic reticulum (ER) stress leads to activation of glycogen synthase kinase 3β (GSK-3β) and X-box-binding protein 1 (XBP-1) in an inositol-requiring enzyme 1α (IRE1α)-mediated manner, which in turn restores the inflammatory response in endotoxin-tolerant macrophages. Animal and in vitro models of endotoxin tolerance were studied along with a model of LPS-induced endotoxin tolerance and a model of cecal ligation and puncture (CLP)-induced endotoxin tolerance. To detect the suppressed inflammatory response during endotoxin tolerance, inflammatory-cytokine expression levels were measured by quantitative real-time PCR and an ELISA. Our research revealed that induction of ER stress alleviated lung injury in a septic host infected with Pseudomonas aeruginosa via the activation of GSK-3β and XBP-1 in an IRE1α-mediated manner. Consequently, in the lungs of the septic host infected with P. aeruginosa, symptoms of pneumonia improved and the infecting bacteria were cleared. Thus, for septic patients, determination of immune status may guide the selection of appropriate immunomodulation, and ER stress can be a novel therapeutic strategy restoring the immune response in patients with endotoxin tolerance. ©2018 Society for Leukocyte Biology.

Increase of chromium tolerance in Scenedesmus acutus after sulfur starvation: Chromium uptake and compartmentalization in two strains with different sensitivities to Cr(VI).

PubMed

Marieschi, M; Gorbi, G; Zanni, C; Sardella, A; Torelli, A

2015-10-01

In photosynthetic organisms sulfate constitutes the main sulfur source for the biosynthesis of GSH and its precursor Cys. Hence, sulfur availability can modulate the capacity to cope with environmental stresses, a phenomenon known as SIR/SED (Sulfur Induced Resistance or Sulfur Enhanced Defence). Since chromate may compete for sulfate transport into the cells, in this study chromium accumulation and tolerance were investigated in relation to sulfur availability in two strains of the unicellular green alga Scenedesmus acutus with different Cr-sensitivities. Paradoxically, sulfur deprivation has been demonstrated to induce a transient increase of Cr-tolerance in both strains. Sulfur deprivation is known to enhance the sulfate uptake/assimilation pathway leading to important consequences on Cr-tolerance: (i) reduced chromate uptake due to the induction of high affinity sulfate transporters (ii) higher production of cysteine and GSH which can play a role both through the formation of unsoluble complexes and their sequestration in inert compartments. To investigate the role of the above mentioned mechanisms, Cr accumulation in total cells and in different cell compartments (cell wall, membranes, soluble and miscellaneous fractions) was analyzed in both sulfur-starved and unstarved cells. Both strains mainly accumulated chromium in the soluble fraction, but the uptake was higher in the wild-type. In this type a short period of sulfur starvation before Cr(VI) treatment lowered chromium accumulation to the level observed in the unstarved Cr-tolerant strain, in which Cr uptake seems instead less influenced by S-starvation, since no significant decrease was observed. The increase in Cr-tolerance following S-starvation seems thus to rely on different mechanisms in the two strains, suggesting the induction of a mechanism constitutively active in the Cr-tolerant strain, maybe a high affinity sulfate transporter also in the wild-type. Changes observed in the cell wall and membrane fractions suggest a strong involvement of these compartments in Cr-tolerance increase following S-starvation. Copyright © 2015 Elsevier B.V. All rights reserved.

Successful reversal of streptozotocin-induced diabetes with stable allogeneic islet function in a preclinical model of type 1 diabetes.

PubMed

Thomas, J M; Contreras, J L; Smyth, C A; Lobashevsky, A; Jenkins, S; Hubbard, W J; Eckhoff, D E; Stavrou, S; Neville, D M; Thomas, F T

2001-06-01

The recent focus on islet transplantation as primary therapy for type 1 diabetes has heightened interest in the reversal of type 1 diabetes in preclinical models using minimal immunosuppression. Here, we demonstrated in a preclinical rhesus model a consistent reversal of all measured glycemic patterns of streptozotocin-induced type 1 diabetes. The model used single-donor islet transplantation with induction of operational tolerance. The term "operational tolerance" is used to indicate durable survival of single-donor major histocompatibility complex (MHC)-mismatched islet allografts without maintenance immunosuppressive therapy and without rejection or loss of functional islet mass or insulin secretory reserve. In this operational tolerance model, all immunosuppression was discontinued after day 14 posttransplant, and recipients recovered with excellent health. The operational tolerance induction protocol combined peritransplant anti-CD3 immunotoxin to deplete T-cells and 15-deoxyspergualin to arrest proinflammatory cytokine production and maturation of dendritic cells. T-cell deficiency was specific but temporary, in that T-cell-dependent responses in long-term survivors recovered to normal, and there was no evidence of increased susceptibility to infection. Anti-donor mixed lymphocyte reaction responses were positive in the long-term survivors, but all showed clear evidence of systemic T-helper 2 deviation, suggesting that an immunoregulatory rather than a deletional process underlies this operational tolerance model. This study provides the first evidence that operational tolerance can protect MHC nonhuman primate islets from rejection as well as loss of functional islet mass. Such an approach has potential to optimize individual recipient recovery from diabetes as well as permitting more widespread islet transplantation with the limited supply of donor islets.

Six years' experience of tolerance induction in renal transplantation using stem cell therapy.

PubMed

Vanikar, Aruna V; Trivedi, Hargovind L; Thakkar, Umang G

2018-02-01

Tolerance induction (TI) has been attempted with chimerism/clonal deletion. We report results of TI protocol (TIP) using stem cell therapy (SCT) included adipose derived mesenchymal stem cells (AD-MSC) and hematopoietic stem cells (HSC) in 10 living-donor related renal transplantation (LDRT) patients under non-myeloablative conditioning with Bortezomib, Methylprednisone, rabbit-anti-thymoglobulin and Rituximab, without using conventional immunosuppression. Transplantation was performed following acceptable lymphocyte cross-match, flow cross-match, single antigen assay and negative mixed lymphocyte reaction (MLR). Monitoring included serum creatinine (SCr), donor specific antibodies (DSA) and MLR. Protocol biopsies were planned after 100days and yearly in willing patients. Rescue immunosuppression was planned for rejection/DSA/positive MLR. Over mean 6±0.37year follow-up patient survival was 80% and death-censored graft survival was 90%. Mean SCr was 1.44±0.41mg/dL. This is the first clinical report of sustained TI in LDRT for 6years using SCT. Copyright © 2017 Elsevier Inc. All rights reserved.

V-set and Ig domain-containing 4 (VSIG4)-expressing hepatic F4/80+ cells regulate oral antigen-specific responses in mouse.

PubMed

Shin, Wonhwa; Jeon, Youkyoung; Choi, Inhak; Kim, Yeon-Jeong

2018-04-01

Oral tolerance can prevent unnecessary immune responses against dietary antigens. Members of the B7 protein family play critical roles in the positive and/or negative regulation of T cell responses to interactions between APCs and T cells. V-set and Ig domain-containing 4 (VSIG4), a B7-related co-signaling molecule, has been known to act as a co-inhibitory ligand and may be critical in establishing immune tolerance. Therefore, we investigated the regulation of VSIG4 signaling in a food allergy and experimental oral tolerance murine models. We analyzed the contributions of the two main sites involved in oral tolerance, the mesenteric lymph node (MLN) and the liver, in VSIG4-mediated oral tolerance induction. Through the comparative analysis of major APCs, dendritic cells (DCs) and macrophages, we found that Kupffer cells play a critical role in inducing regulatory T cells (Tregs) and establishing immune tolerance against oral antigens via VSIG4 signaling. Taken together, these results suggest the possibility of VSIG4 signaling-based regulation of orally administered antigens. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intragraft Molecular Pathways Associated with Tolerance Induction in Renal Transplantation.

PubMed

Gallon, Lorenzo; Mathew, James M; Bontha, Sai Vineela; Dumur, Catherine I; Dalal, Pranav; Nadimpalli, Lakshmi; Maluf, Daniel G; Shetty, Aneesha A; Ildstad, Suzanne T; Leventhal, Joseph R; Mas, Valeria R

2018-02-01

The modern immunosuppression regimen has greatly improved short-term allograft outcomes but not long-term allograft survival. Complications associated with immunosuppression, specifically nephrotoxicity and infection risk, significantly affect graft and patient survival. Inducing and understanding pathways underlying clinical tolerance after transplantation are, therefore, necessary. We previously showed full donor chimerism and immunosuppression withdrawal in highly mismatched allograft recipients using a bioengineered stem cell product (FCRx). Here, we evaluated the gene expression and microRNA expression profiles in renal biopsy samples from tolerance-induced FCRx recipients, paired donor organs before implant, and subjects under standard immunosuppression (SIS) without rejection and with acute rejection. Unlike allograft samples showing acute rejection, samples from FCRx recipients did not show upregulation of T cell- and B cell-mediated rejection pathways. Gene expression pathways differed slightly between FCRx samples and the paired preimplantation donor organ samples, but most of the functional gene networks overlapped. Notably, compared with SIS samples, FCRx samples showed upregulation of genes involved in pathways, like B cell receptor signaling. Additionally, prediction analysis showed inhibition of proinflammatory regulators and activation of anti-inflammatory pathways in FCRx samples. Furthermore, integrative analyses (microRNA and gene expression profiling from the same biopsy sample) identified the induction of regulators with demonstrated roles in the downregulation of inflammatory pathways and maintenance of tissue homeostasis in tolerance-induced FCRx samples compared with SIS samples. This pilot study highlights the utility of molecular intragraft evaluation of pathways related to FCRx-induced tolerance and the use of integrative analyses for identifying upstream regulators of the affected downstream molecular pathways. Copyright © 2018 by the American Society of Nephrology.

Multicenter phase II study of weekly docetaxel, cisplatin, and S-1 (TPS) induction chemotherapy for locally advanced squamous cell cancer of the head and neck.

PubMed

Bae, Woo Kyun; Hwang, Jun Eul; Shim, Hyun Jeong; Cho, Sang Hee; Lee, Ki Hyeong; Han, Hye Suk; Song, Eun-Kee; Yun, Hwan Jung; Cho, In Sung; Lee, Joon Kyoo; Lim, Sang-Chul; Chung, Woong-Ki; Chung, Ik-Joo

2013-03-06

The purpose of this study was to evaluate the efficacy and tolerability of weekly docetaxel, cisplatin, and S-1 (weekly TPS) as induction chemotherapy for patients with locally advanced head and neck squamous cell carcinoma (HNSCC). A total of 35 patients with previously untreated, locally advanced HNSCC were enrolled. Seven patients (20%) were diagnosed with stage III HNSCC and 28 patients (80%) were diagnosed with stage IV. Induction treatment included 30 mg/m(2) docetaxel on day 1 and 8, 60 mg/m(2) cisplatin on day 1, and 70 mg/m(2) S-1 on days 1 to 14. The regimen was repeated every 21 days. After three courses of induction chemotherapy, patients received concurrent chemoradiotherapy. Among the 35 patients, 30 (85.7%) completed induction chemotherapy. The response to induction chemotherapy was as follows: nine patients (25.7%) achieved a complete response (CR) and the overall response rate (ORR) was 85.7%. Grades 3-4 toxicity during induction therapy included neutropenia (28.5%), neutropenic fever (8.5%), and diarrhea (17.1%). After completion of concurrent chemoradiotherapy, the CR rate was 62.8% and the partial response (PR) was 22.8%. Estimates of progression-free and overall survival at 2 years were 73.2% and 79.3%, respectively. Weekly TPS is a promising regimen that is well-tolerated, causes minimal myelosuppression and is effective as an outpatient regimen for locally advanced HNSCC. ClinicalTrials.gov: NCT01645748.

Impact of pr-10a overexpression on the cryopreservation success of Solanum tuberosum suspension cultures.

PubMed

Vaas, Lea A I; Marheine, Maja; Seufert, Stephanie; Schumacher, Heinz Martin; Kiesecker, Heiko; Heine-Dobbernack, Elke

2012-06-01

Although many genes are supposed to be a part of plant cell tolerance mechanisms against osmotic or salt stress, their influence on tolerance towards stress during cryopreservation procedures has rarely been investigated. For instance, the overexpression of the pathogenesis-related gene 10a (pr-10a) leads to improved osmotic tolerance in a transgenic cell culture of Solanum tuberosum cv. Désirée. In this study, a cryopreservation method, consisting of osmotic pretreatment, cryoprotection with DMSO and controlled-rate freezing, was used to characterize the relation between cryopreservation success and pr-10a expression in suspension cultures of S. tuberosum wild-type cells and cells overexpressing pathogenesis-related protein 10a (Pr-10a). By varying the sorbitol concentration, thus modifying the strength of the osmotic stress during the pretreatment phase, it can be shown that the wild type can successfully be cryopreserved only in a relatively narrow range of sorbitol concentrations, while the pr-10a overexpression leads to an enhanced cryopreservation success over the whole range of applied sorbitol concentrations. Together with transcription data we show that the pr-10a overexpression causes an enhanced osmotic tolerance, which in turn leads to enhanced cryopreservability, but also indicates a role of pr-10a in signal transduction. An increased cryopreservability of the transgenic cell line occurs for pretreatments longer than 24 h. Since both genotypes, characterized by distinct baseline levels of expression, exhibited similar patterns of expression induction, the induction of pr-10a appears to be a key step in the stress signal transduction of plant cells under osmotic stress.

Failure of transplantation tolerance induction by autologous regulatory T cells in the pig-to-non-human primate islet xenotransplantation model.

PubMed

Shin, Jun-Seop; Min, Byoung-Hoon; Kim, Jong-Min; Kim, Jung-Sik; Yoon, Il Hee; Kim, Hyun Je; Kim, Yong-Hee; Jang, Jae Yool; Kang, Hee Jung; Lim, Dong-Gyun; Ha, Jongwon; Kim, Sang-Joon; Park, Chung-Gyu

2016-07-01

Islet allotransplantation is a promising way to treat some type 1 diabetic (T1D) patients with frequent hypoglycemic unawareness, and islet xenotransplantation is emerging to overcome the problem of donor organ shortage. Our recent study showing reproducible long-term survival of porcine islets in non-human primates (NHPs) allows us to examine whether autologous regulatory T-cell (Treg) infusion at peri-transplantation period would induce transplantation tolerance in xenotransplantation setting. Two diabetic rhesus monkeys were transplanted with porcine islets from wild-type adult Seoul National University (SNU) miniature pigs with immunosuppression by anti-thymoglobulin (ATG), cobra venom factor, anti-CD154 monoclonal antibody (mAb), and sirolimus. CD4(+) CD25(high) CD127(low) autologous regulatory T cells from the recipients were isolated, ex vivo expanded, and infused at the peri-transplantation period. Blood glucose and porcine C-peptide from the recipients were measured up to 1000 days. Maintenance immunosuppressants including a CD40-CD154 blockade were deliberately discontinued to confirm whether transplantation tolerance was induced by adoptively transferred Tregs. After pig islet transplantation via portal vein, blood glucose levels of diabetic recipients became normalized and maintained over 6 months while in immunosuppressive maintenance with a CD40-CD154 blockade and sirolimus. However, the engrafted pig islets in the long-term period were fully rejected by activated immune cells, particularly T cells, when immunosuppressants were stopped, showing a failure of transplantation tolerance induction by autologous Tregs. Taken together, autologous Tregs infused at the peri-transplantation period failed to induce transplantation tolerance in pig-to-NHP islet xenotransplantation setting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Tolerance induction after specific immunotherapy with pollen allergoids adjuvanted by monophosphoryl lipid A in children

PubMed Central

Rosewich, M; Schulze, J; Eickmeier, O; Telles, T; Rose, M A; Schubert, R; Zielen, S

2010-01-01

Specific immunotherapy (SIT) is a well-established and clinically effective treatment for allergic diseases. A pollen allergoid formulated with the T helper type 1 (Th1)-inducing adjuvant monophosphoryl lipid A (MPL) facilitates short-term SIT. Little is known about mechanisms of tolerance induction in this setting. In a prospective study, 34 patients allergic to grass pollen (25 male, nine female, median age 10·2 years) received a total of 44 SIT courses (20 in the first, 24 in the second) with MPL-adjuvanted pollen allergoids. Immunogenicity was measured by levels of specific immunoglobulin G (IgGgrass) and IgG4grass by antibody blocking properties on basophil activation, and by induction of CD4+, CD25+ and forkhead box P3 (FoxP3+) regulatory T cells (Treg). Specific IgG and IgG4 levels increased only slightly in the first year of SIT. In the second year these changes reached significance (P < 0·0001). In keeping with these findings, we were able to show an increase of Treg cells and a decreased release of leukotrienes after the second year of treatment. In the first year of treatment we found little evidence for immunological changes. A significant antibody induction was seen only after the second course of SIT. Short-course immunotherapy with pollen allergoids formulated with the Th1-inducing adjuvant MPL needs at least two courses to establish tolerance. PMID:20345983

Tolerance induction after specific immunotherapy with pollen allergoids adjuvanted by monophosphoryl lipid A in children.

PubMed

Rosewich, M; Schulze, J; Eickmeier, O; Telles, T; Rose, M A; Schubert, R; Zielen, S

2010-06-01

Specific immunotherapy (SIT) is a well-established and clinically effective treatment for allergic diseases. A pollen allergoid formulated with the T helper type 1 (Th1)-inducing adjuvant monophosphoryl lipid A (MPL) facilitates short-term SIT. Little is known about mechanisms of tolerance induction in this setting. In a prospective study, 34 patients allergic to grass pollen (25 male, nine female, median age 10.2 years) received a total of 44 SIT courses (20 in the first, 24 in the second) with MPL-adjuvanted pollen allergoids. Immunogenicity was measured by levels of specific immunoglobulin G (IgG(grass)) and IgG4(grass) by antibody blocking properties on basophil activation, and by induction of CD4(+), CD25(+) and forkhead box P3 (FoxP3(+)) regulatory T cells (T(reg)). Specific IgG and IgG4 levels increased only slightly in the first year of SIT. In the second year these changes reached significance (P < 0.0001). In keeping with these findings, we were able to show an increase of T(reg) cells and a decreased release of leukotrienes after the second year of treatment. In the first year of treatment we found little evidence for immunological changes. A significant antibody induction was seen only after the second course of SIT. Short-course immunotherapy with pollen allergoids formulated with the Th1-inducing adjuvant MPL needs at least two courses to establish tolerance.

Differential regulation of peripheral CD4+ T cell tolerance induced by deletion and TCR revision.

PubMed

Ali, Mohamed; Weinreich, Michael; Balcaitis, Stephanie; Cooper, Cristine J; Fink, Pamela J

2003-12-01

In Vbeta5 transgenic mice, mature Vbeta5(+)CD4(+) T cells are tolerized upon recognition of a self Ag, encoded by a defective endogenous retrovirus, whose expression is confined to the lymphoid periphery. Cells are driven by the tolerogen to enter one of two tolerance pathways, deletion or TCR revision. CD4(+) T cells entering the former pathway are rendered anergic and then eliminated. In contrast, TCR revision drives gene rearrangement at the endogenous TCR beta locus and results in the appearance of Vbeta5(-), endogenous Vbeta(+), CD4(+) T cells that are both self-tolerant and functional. An analysis of the molecules that influence each of these pathways was conducted to understand better the nature of the interactions that control tolerance induction in the lymphoid periphery. These studies reveal that deletion is efficient in reconstituted radiation chimeras and is B cell, CD28, inducible costimulatory molecule, Fas, CD4, and CD8 independent. In contrast, TCR revision is radiosensitive, B cell, CD28, and inducible costimulatory molecule dependent, Fas and CD4 influenced, and CD8 independent. Our data demonstrate the differential regulation of these two divergent tolerance pathways, despite the fact that they are both driven by the same tolerogen and restricted to mature CD4(+) T cells.

An approach to natalizumab hypersensitivity: a case series of induction of tolerance.

PubMed

Camacho-Halili, Marie; George, Roxanne; Gottesman, Malcolm; Davis-Lorton, Mark

2011-02-01

Induction of tolerance protocols have been applied successfully to manage allergic reactions to many medications. Hypersensitivity reactions to natalizumab (TYSABRI®) have been recognized as a growing problem. In circumstances where a hypersensitivity reaction to a medication has occurred, but no suitable alternative exists, drug induction of tolerance protocols may be considered. Drug induction of tolerance protocols were performed in three patients with prior hypersensitivity reactions to natalizumab. All three patients tolerated the protocol without adverse reactions, allowing for the safe reintroduction of natalizumab. To conclude, this case series demonstrates success with an induction of tolerance procedure to a highly effective biological agent for multiple sclerosis, in patients with allergic reactions to natalizumab.

78 FR 37468 - Cyproconazole; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-21

..., and single-cell necrosis. For both subchronic and chronic durations, hepatotoxicity was observed in... = 1X..... LOAEL = 3.2 mg/kg/day based on liver effects (P450 induction in females and histopathology...

Mixed chimerism and split tolerance

PubMed Central

Al-Adra, David P.

2011-01-01

Establishing hematopoietic mixed chimerism can lead to donor-specific tolerance to transplanted organs and may eliminate the need for long-term immunosuppressive therapy, while also preventing chronic rejection. In this review, we discuss central and peripheral mechanisms of chimerism induced tolerance. However, even in the long-lasting presence of a donor organ or donor hematopoietic cells, some allogeneic tissues from the same donor can be rejected; a phenomenon known as split tolerance. With the current goal of creating mixed chimeras using clinically feasible amounts of donor bone marrow and with minimal conditioning, split tolerance may become more prevalent and its mechanisms need to be explored. Some predisposing factors that may increase the likelihood of split tolerance are immunogenicity of the graft, certain donor-recipient combinations, prior sensitization, location and type of graft and minimal conditioning chimerism induction protocols. Additionally, split tolerance may occur due to a differential susceptibility of various types of tissues to rejection. The mechanisms involved in a tissue’s differential susceptibility to rejection include the presence of polymorphic tissue-specific antigens and variable sensitivity to indirect pathway effector mechanisms. Finally, we review the clinical attempts at allograft tolerance through the induction of chimerism; studies that are revealing the complex relationship between chimerism and tolerance. This relationship often displays split tolerance, and further research into its mechanisms is warranted. PMID:22509425

A comparison of sputum induction methods: ultrasonic vs compressed-air nebulizer and hypertonic vs isotonic saline inhalation.

PubMed

Loh, L C; Eg, K P; Puspanathan, P; Tang, S P; Yip, K S; Vijayasingham, P; Thayaparan, T; Kumar, S

2004-03-01

Airway inflammation can be demonstrated by the modem method of sputum induction using ultrasonic nebulizer and hypertonic saline. We studied whether compressed-air nebulizer and isotonic saline which are commonly available and cost less, are as effective in inducing sputum in normal adult subjects as the above mentioned tools. Sixteen subjects underwent weekly sputum induction in the following manner: ultrasonic nebulizer (Medix Sonix 2000, Clement Clarke, UK) using hypertonic saline, ultrasonic nebulizer using isotonic saline, compressed-air nebulizer (BestNeb, Taiwan) using hypertonic saline, and compressed-air nebulizer using isotonic saline. Overall, the use of an ultrasonic nebulizer and hypertonic saline yielded significantly higher total sputum cell counts and a higher percentage of cell viability than compressed-air nebulizers and isotonic saline. With the latter, there was a trend towards squamous cell contaminations. The proportion of various sputum cell types was not significantly different between the groups, and the reproducibility in sputum macrophages and neutrophils was high (Intraclass correlation coefficient, r [95%CI]: 0.65 [0.30-0.91] and 0.58 [0.22-0.89], p < 0.001). Overall changes in median FEV, were small and comparable between all groups. Induction using ultrasonic nebulizers together with hypertonic saline was generally less well tolerated than compressed-air nebulizers and isotonic saline. We conclude that in normal subjects, although both nebulizers and saline types can induce sputum with reproducible cellular profile, ultrasonic nebulizers and hypertonic saline are more effective but less well tolerated.

Opposite extremes in ethylene/nitric oxide ratio induce cell death in suspension culture and root apices of tomato exposed to salt stress.

PubMed

Poór, P; Borbély, P; Kovács, Judit; Papp, Anita; Szepesi, Ágnes; Takács, Z; Tari, Irma

2014-12-01

The plant hormone ethylene or the gaseous signalling molecule nitric oxide (NO) may enhance salt stress tolerance by maintaining ion homeostasis, first of all K+/Na+ ratio of tissues. Ethylene and NO accumulation increased in the root apices and suspension culture cells of tomato at sublethal salt stress caused by 100 mM NaCl, however, the induction phase of programmed cell death (PCD) was different at lethal salt concentration. The production of ethylene by root apices and the accumulation of NO in the cells of suspension culture did not increase during the initiation of PCD after 250 mM NaCl treatment. Moreover, cells in suspension culture accumulated higher amount of reactive oxygen species which, along with NO deficiency contributed to cell death induction. The absence of ethylene in the apical root segments and the absence of NO accumulation in the cell suspension resulted in similar ion disequilibrium, namely K+/Na+ ratio of 1.41 ± 0.1 and 1.68 ± 0.3 in intact plant tissues and suspension culture cells, respectively that was not tolerated by tomato.

PDC expressing CD36, CD61 and IL-10 may contribute to propagation of immune tolerance.

PubMed

Parcina, Marijo; Schiller, Martin; Gierschke, Aline; Heeg, Klaus; Bekeredjian-Ding, Isabelle

2009-05-01

Human plasmacytoid dendritic cells (PDC) are blood dendritic cell antigen 2 (BDCA2) and blood dendritic cell antigen 4 (BDCA4) positive leukocytes that do not express common lineage markers. They have been described as proinflammatory innate immune cells and are the major source of alphaIFN in the human body. PDC-derived secretion of type I IFNs upon triggering of nucleic acid-sensing toll-like receptors (TLR) primes immune cells to rapidly respond to microbial stimuli and promotes a Th1 response. Here, we report that human PDC express CD36 and CD61 (beta3 integrin), both involved in uptake of apoptotic cells and in induction of tolerance. Freshly isolated PDC and PDC within human blood leukocytes constitutively express IL-10. Thus, PDC may possess a so far neglected role in propagation of immune tolerance.

Rejection triggers liver transplant tolerance: Involvement of mesenchyme-mediated immune control mechanisms in mice.

PubMed

Morita, Miwa; Joyce, Daniel; Miller, Charles; Fung, John J; Lu, Lina; Qian, Shiguang

2015-09-01

Liver tolerance was initially recognized by the spontaneous acceptance of liver allografts in many species. The underlying mechanisms are not completely understood. However, liver transplant (LT) tolerance absolutely requires interferon (IFN)-γ, a rejection-associated inflammatory cytokine. In this study, we investigated the rejection of liver allografts deficient in the IFN-γ receptor and reveal that the liver graft is equipped with machineries capable of counterattacking the host immune response through a mesenchyme-mediated immune control (MMIC) mechanism. MMIC is triggered by T effector (Tef) cell-derived IFN-γ that drives expression of B7-H1 on graft mesenchymal cells leading to Tef cell apoptosis. We describe the negative feedback loop between graft mesenchymal and Tef cells that ultimately results in LT tolerance. Comparable elevations of T-regulatory cells and myeloid-derived suppressor cells were observed in both rejection and tolerance groups and were not dependent on IFN-γ stimulation, suggesting a critical role of Tef cell elimination in tolerance induction. We identify potent MMIC activity in hepatic stellate cells and liver sinusoidal endothelial cells. MMIC is unlikely exclusive to the liver, given that spontaneous acceptance of kidney allografts has been reported, although less commonly, probably reflecting variance in MMIC activity. MMIC may represent an important homeostatic mechanism that supports peripheral tolerance and could be a target for the prevention and treatment of transplant rejection. This study highlights that the graft is an active participant in the equipoise between tolerance and rejection and warrants more attention in the search for tolerance biomarkers. © 2015 by the American Association for the Study of Liver Diseases.

Rejection Triggers Liver Transplant Tolerance: Involvements of Mesenchyme-Mediated Immune Control Mechanisms

PubMed Central

Morita, Miwa; Joyce, Daniel; Miller, Charles; Fung, John J.; Lu, Lina; Qian, Shiguang

2015-01-01

Liver tolerance was initially recognized by the spontaneous acceptance of liver allograft in many species. The underlying mechanisms are not completely understood. We have been inspired by an unexpected phenomenon that the liver transplant tolerance absolutely requires interferon (IFN)-γ, a rejection-associated inflammatory cytokine. In this study, we investigate the rejection of liver allografts deficient in IFN-γ receptor and reveal that the liver graft is equipped with machineries capable of counterattacking the host immune response through a mesenchyme-mediated immune control (MMIC) mechanism. MMIC is triggered by T effectors (Tef) cell-derived IFN-γ to drive the expression of B7-H1 on graft mesenchymal cells leading to Tef cell apoptosis. We describe the negative feedback loop between graft mesenchymal and Tef cells that ultimately results in liver transplant tolerance. Comparable elevations of T regulatory cells and myeloid-derived suppressor cells are seen in both rejection and tolerance groups, and are not dependent on IFN-γ stimulation, suggesting a critical role of Tef cell elimination in tolerance induction. We identify potent MMIC activity in hepatic stellate cells and liver sinusoidal endothelial cells. MMIC is unlikely exclusive to the liver, as spontaneous acceptance of kidney allografts has been reported, although less commonly, probably reflecting variance in MMIC activity. MMCI may represent an important homeostatic mechanism that supports peripheral tolerance, and could be a target for the prevention and treatment of transplant rejection. This study highlights that the graft is actively participant in the equipoise between tolerance and rejection and warrants more attention in the search for tolerance biomarkers. PMID:25998530

Reduced-intensity conditioning for the treatment of malignant and life-threatening non-malignant disorders.

PubMed

Slavin, Shimon; Aker, Mehmet; Shapira, Michael Y; Resnick, Igor; Bitan, Menachem; Or, Reuven

2003-01-01

Allogeneic bone marrow or blood stem cell transplantation (BMT) represents an important therapeutic tool for the treatment of an otherwise incurable broad spectrum of malignant and non-malignant diseases. Until recently, BMT was used primarily to replace a malignant, genetically abnormal or deficient immunohematopoietic compartment and therefore, highly toxic myeloablative regimens were considered mandatory for more effective eradication of all undesirable host-derived hematopoietic cells, including stem cells and their progeny. Our preclinical and ongoing clinical studies indicated that much more effective eradication of host immunohematopoietic system cells can be mediated by donor lymphocytes in the process of adoptive allogeneic cell therapy following BMT. Thus, eradication of all malignant cells, especially in patients with CML and, to a lesser extent, in patients with other hematologic malignancies can be accomplished despite complete resistance of puch tumor cells to maximally tolerated doses of chemoradiotherapy. Our cumulative experience suggested that graft-versus-malignancy effects might be used as a tool for eradication of otherwise resistant tumor cells of host origin. We speculated that the therapeutic benefit of BMT may be improved by using safer conditioning for engraftment of donor stem cells induce host-versus-graft unresponsiveness to enable engraftment of donor lymphocytes for subsequent induction of graft-versus-malignancy effects, or even graft-versus-autoimmunity and graft-versus-genetically abnormal cells. In other words, focusing on more selective and smarter rather than stronger modalities. Effective BMT procedures may be accomplished without lethal conditioning of the host, using a new, well-tolerated and user-friendly non-myeloablative regimen, thus eliminating or minimizing immediate and late procedure-related toxicity and mortality. It appears that initial induction of graft tolerance, mediated by engraftment of donor stem cells, leads to durable engraftment of immunocompetent donor lymphocytes, which may be necessary for induction of effective biologic warfare against host-type immunohematopoietic cells. Consequently, stem-cell therapy following induction of transplantation tolerance by selective elimination of alloreactive donor lymphocytes may represent the treatment of choice for a wide range of otherwise incurable diseases, including cancer (hematologic malignancies and certain metastatic solid tumors), genetic disorders (hemoglobinopathies and enzyme deficiency disorders), diseases caused by self-reactive lymphocytes (autoimmune diseases such as multiple sclerosis, rheumatoid arthritis) to mention just a few. Using reduced intensity conditioning, non-myeloablative stem cell transplantation (NST) can be accomplished with no major procedure-related toxicity or mortality. Thus, NST offers the feasibility of safe stem cell transplantation and cell-mediated procedures for a large and constantly growing spectrum of clinical indications for all patients in need without lower or upper age limit. Future strategies currently under investigation include developing new approaches for control of alloreactivity of host-versus-graft and graft-versus host reactivity reactions and developing better approaches for maximizing the capacity of donor lymphocytes to eliminate cancer cells more selectively, while avoiding or minimizing GVHD for safer and more effective treatment of patients in need of BMT.

Previous Ingestion of Lactococcus lactis by Ethanol-Treated Mice Preserves Antigen Presentation Hierarchy in the Gut and Oral Tolerance Susceptibility.

PubMed

Alvarenga, Débora M; Perez, Denise A; Gomes-Santos, Ana C; Miyoshi, Anderson; Azevedo, Vasco; Coelho-Dos-Reis, Jordana G A; Martins-Filho, Olindo A; Faria, Ana Maria C; Cara, Denise C; Andrade, Marileia C

2015-08-01

Ethanol (EtOH) consumption is able to disturb the ovalbumin (OVA)-oral tolerance induction by interfering on the function of antigen presenting cells (APC), down-regulating dendritic cells (DCs) and macrophages and up-regulating B-lymphocytes and their function, which results in an overall allergic-type immune status. In this study, the potential of a priori administration of Lactococcus lactis (LL) in avoiding loss of oral tolerance in EtOH-treated mice was investigated. Female C57BL/6 mice received, by oral route, ad libitum wild-type (WT) LL or heat-shock protein producer (Hsp65) LL for 4 consecutive days. Seven days later, mice were submitted to short-term high-dose EtOH treatment. After 24 hours, stomach, intestine, spleen, mesenteric lymph nodes (mLN) specimens were collected for biomarkers analysis. Following EtOH-treatment protocol, a group of animals underwent single-gavage OVA-tolerance protocol and sera samples collected for antibody analysis. The ingestion of WT LL or Hsp65 LL is able to restore oral tolerance to OVA in EtOH-treated mice, by reducing local and systemic allergic outcomes such as gastric mast cells and gut-interleukin-4, as well as serum IgE. WT LL treatment prevents the decrease of mLN regulatory T cells induced by the EtOH treatment. Moreover, LL treatment preserves APC hierarchy and antigen presentation commitment in EtOH-treated mice, with conserved DC and macrophage activity over B lymphocytes in mLN and preserved macrophage activity over DC and B-cell subsets in the spleen. The present findings suggest that a priori ingestion of LL preserves essential mechanisms associated with oral tolerance induction that are disturbed by EtOH ingestion. Maintenance of mucosal homeostasis by preserving APC hierarchy and antigen presentation commitment could be associated with T-regulatory subset activities in the gastrointestinal tract. Copyright © 2015 by the Research Society on Alcoholism.

Applications and mechanisms of immunotherapy in allergic rhinitis and asthma.

PubMed

Kappen, Jasper H; Durham, Stephen R; Veen, Hans In 't; Shamji, Mohamed H

2017-01-01

Clinical and immunologic tolerance are hallmarks of successful allergen immunotherapy (AIT). Clinical benefits such as reduced symptoms, pharmacotherapy intake and improvement of quality of life persist following cessation of treatment. Successful AIT is associated with suppression of allergic inflammatory cells such as mast cells, eosinophils and basophils in target organs. Furthermore, AIT down-regulates type 2 innate lymphoid cells and allergen-specific type 2 T-helper (Th2) cells. The immunologic tolerant state following AIT is associated with the induction of distinct phenotypes of regulatory T-cells (T-regs) including interleukin (IL)-10-, IL-35- and transforming growth factor (TGF)-β- producing T-regs and FoxP3 + T-regs. B-cell responses, including the induction of IL-10 + regulatory B-cells (B-regs) and the production of IgG4-associated blocking antibodies are also induced following successful AIT. These events are associated with the suppression of antigen-specific Th2 responses and delayed immune deviation in favour of Th1 type responses. Insight into the mechanisms of AIT has allowed identification of novel biomarkers with potential to predict the clinical response to AIT and also novel therapeutic strategies for more effective and safer AIT.

Zinc tolerance and accumulation in stable cell suspension cultures and in vitro regenerated plants of the emerging model plant Arabidopsis halleri (Brassicaceae).

PubMed

Vera-Estrella, Rosario; Miranda-Vergara, Maria Cristina; Barkla, Bronwyn J

2009-03-01

Arabidopsis halleri is increasingly employed as a model plant for studying heavy metal hyperaccumulation. With the aim of providing valuable tools for studies on cellular physiology and molecular biology of metal tolerance and transport, this study reports the development of successful and highly efficient methods for the in vitro regeneration of A. halleri plants and production of stable cell suspension lines. Plants were regenerated from leaf explants of A. halleri via a three-step procedure: callus induction, somatic embryogenesis and shoot development. Efficiency of callus proliferation and regeneration depended on the initial callus induction media and was optimal in the presence of 1 mg L(-1) 2,4-dichlorophenoxyacetic acid, and 0.05 mg L(-1) benzylaminopurine. Subsequent shoot and root regeneration from callus initiated under these conditions reached levels of 100% efficiency. High friability of the callus supported the development of cell suspension cultures with minimal cellular aggregates. Characterization of regenerated plants and cell cultures determined that they maintained not only the zinc tolerance and requirement of the whole plant but also the ability to accumulate zinc; with plants accumulating up to 50.0 micromoles zinc g(-1) FW, and cell suspension cultures 30.9 micromoles zinc g(-1) DW. Together this work will provide the experimental basis for furthering our knowledge of A. halleri as a model heavy metal hyperaccumulating plant.

Myelin-reactive “type B” T cells and T cells specific for low-affinity MHC-binding myelin peptides escape tolerance in HLA-DR transgenic mice

PubMed Central

Kawamura, Kazuyuki; McLaughlin, Katherine A.; Weissert, Robert; Forsthuber, Thomas G.

2009-01-01

Genes of the major histocompatibility complex (MHC) show the strongest genetic association with multiple sclerosis (MS) but the underlying mechanisms have remained unresolved. Here, we asked whether the MS-associated MHC class II molecules, HLA-DRB1*1501, HLA-DRB5*0101, and HLA-DRB1*0401 contribute to autoimmune central nervous system (CNS) demyelination by promoting pathogenic T cell responses to human myelin basic protein (hMBP), using three transgenic (Tg) mouse lines expressing these MHC molecules. Unexpectedly, profound T cell tolerance to the high-affinity MHC-binding hMBP82-100 epitope was observed in all Tg mouse lines. T cell tolerance to hMBP82-100 was abolished upon backcrossing the HLA-DR Tg mice to MBP-deficient mice. In contrast, T cell tolerance was incomplete for low-affinity MHC-binding hMBP epitopes. Furthermore, hMBP82-100-specific “type B” T cells escaped tolerance in HLA-DRB5*0101 Tg mice. Importantly, T cells specific for low-affinity MHC-binding hMBP epitopes and hMBP82-100-specific “type B” T cells were highly encephalitogenic. Collectively, the results show that MS-associated MHC class II molecules are highly efficient at inducing T cell tolerance to high-affinity MHC-binding epitope, whereas autoreactive T cells specific for the low-affinity MHC-binding epitopes and “type B” T cells can escape the induction of T cell tolerance and may promote MS. PMID:18713991

High-dose bee venom exposure induces similar tolerogenic B-cell responses in allergic patients and healthy beekeepers.

PubMed

Boonpiyathad, T; Meyer, N; Moniuszko, M; Sokolowska, M; Eljaszewicz, A; Wirz, O F; Tomasiak-Lozowska, M M; Bodzenta-Lukaszyk, A; Ruxrungtham, K; van de Veen, W

2017-03-01

The involvement of B cells in allergen tolerance induction remains largely unexplored. This study investigates the role of B cells in this process, by comparing B-cell responses in allergic patients before and during allergen immunotherapy (AIT) and naturally exposed healthy beekeepers before and during the beekeeping season. Circulating B cells were characterized by flow cytometry. Phospholipase A2 (PLA)-specific B cells were identified using dual-color staining with fluorescently labeled PLA. Expression of regulatory B-cell-associated surface markers, interleukin-10, chemokine receptors, and immunoglobulin heavy-chain isotypes, was measured. Specific and total IgG1, IgG4, IgA, and IgE from plasma as well as culture supernatants of PLA-specific cells were measured by ELISA. Strikingly, similar responses were observed in allergic patients and beekeepers after venom exposure. Both groups showed increased frequencies of plasmablasts, PLA-specific memory B cells, and IL-10-secreting CD73 - CD25 + CD71 + B R 1 cells. Phospholipase A2-specific IgG4-switched memory B cells expanded after bee venom exposure. Interestingly, PLA-specific B cells showed increased CCR5 expression after high-dose allergen exposure while CXCR4, CXCR5, CCR6, and CCR7 expression remained unaffected. This study provides the first detailed characterization of allergen-specific B cells before and after bee venom tolerance induction. The observed B-cell responses in both venom immunotherapy-treated patients and naturally exposed beekeepers suggest a similar functional immunoregulatory role for B cells in allergen tolerance in both groups. These findings can be investigated in other AIT models to determine their potential as biomarkers of early and successful AIT responses. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Innovative Approaches for Immune Tolerance to Factor VIII in the Treatment of Hemophilia A

PubMed Central

Sherman, Alexandra; Biswas, Moanaro; Herzog, Roland W.

2017-01-01

Hemophilia A (coagulation factor VIII deficiency) is a debilitating genetic disorder that is primarily treated with intravenous replacement therapy. Despite a variety of factor VIII protein formulations available, the risk of developing anti-dug antibodies (“inhibitors”) remains. Overall, 20–30% of patients with severe disease develop inhibitors. Current clinical immune tolerance induction protocols to eliminate inhibitors are not effective in all patients, and there are no prophylactic protocols to prevent the immune response. New experimental therapies, such as gene and cell therapies, show promising results in pre-clinical studies in animal models of hemophilia. Examples include hepatic gene transfer with viral vectors, genetically engineered regulatory T cells (Treg), in vivo Treg induction using immune modulatory drugs, and maternal antigen transfer. Furthermore, an oral tolerance protocol is being developed based on transgenic lettuce plants, which suppressed inhibitor formation in hemophilic mice and dogs. Hopefully, some of these innovative approaches will reduce the risk of and/or more effectively eliminate inhibitor formation in future treatment of hemophilia A. PMID:29225598

Endogenous Memory CD8 T Cells Directly Mediate Cardiac Allograft Rejection

PubMed Central

Su, C. A.; Iida, S.; Abe, T.; Fairchild, R. L.

2014-01-01

Differences in levels of environmentally induced memory T cells that cross-react with donor MHC molecules are postulated to account for the efficacy of allograft tolerance inducing strategies in rodents versus their failure in nonhuman primates and human transplant patients. Strategies to study the impact of donor-reactive memory T cells on allografts in rodents have relied on the pre-transplant induction of memory T cells cross-reactive with donor allogeneic MHC molecules through recipient viral infection, priming directly with donor antigen, or adoptive transfer of donor-antigen primed memory T cells. Each approach accelerates allograft rejection and confers resistance to tolerance induction, but also biases the T cell repertoire to strong donor-reactivity. The ability of endogenous memory T cells within unprimed mice to directly reject an allograft is unknown. Here we show a direct association between increased duration of cold ischemic allograft storage and numbers and enhanced functions of early graft infiltrating endogenous CD8 memory T cells. These T cells directly mediate rejection of allografts subjected to prolonged ischemia and this rejection is resistant to costimulatory blockade. These findings recapitulate the clinically significant impact of endogenous memory T cells with donor reactivity in a mouse transplant model in the absence of prior recipient priming. PMID:24502272

Immunological self-tolerance: Lessons from mathematical modeling

NASA Astrophysics Data System (ADS)

Carneiro, Jorge; Paixao, Tiago; Milutinovic, Dejan; Sousa, Joao; Leon, Kalet; Gardner, Rui; Faro, Jose

2005-12-01

One of the fundamental properties of the immune system is its capacity to avoid autoimmune diseases. The mechanism underlying this process, known as self-tolerance, is hitherto unresolved but seems to involve the control of clonal expansion of autoreactive lymphocytes. This article reviews mathematical modeling of self-tolerance, addressing two specific hypotheses. The first hypothesis posits that self-tolerance is mediated by tuning of activation thresholds, which makes autoreactive T lymphocytes reversibly "anergic" and unable to proliferate. The second hypothesis posits that the proliferation of autoreactive T lymphocytes is instead controlled by specific regulatory T lymphocytes. Models representing the population dynamics of autoreactive T lymphocytes according to these two hypotheses were derived. For each model we identified how cell density affects tolerance, and predicted the corresponding phase spaces and bifurcations. We show that the simple induction of proliferative anergy, as modeled here, has a density dependence that is only partially compatible with adoptive transfers of tolerance, and that the models of tolerance mediated by specific regulatory T cells are closer to the observations.

New approaches to the prevention of organ allograft rejection and tolerance induction.

PubMed

Bagley, Jessamyn; Tian, Chaorui; Iacomini, John

2007-07-15

The therapeutic use of organ allograft transplantation is dependent on the discovery and clinical application of immunologic strategies to blunt the immune response and prevent graft rejection. It was the discovery of powerful immunotherapeutics such as cyclosporine A and rapamycin that has allowed for the widespread use of organ transplantation to treat organ failure. However, despite the attainment of impressive survival rates 1 year after organ transplantation, a significant number of organ allografts are lost to immune-mediated chronic rejection. Furthermore, significant morbidity and mortality can be associated with the use of currently available immunosuppressive regimens. Thus, the development of novel approaches to prevent of organ allograft rejection remains extremely important. Here we discuss two promising and novel avenues of research. First, the discovery and characterization of naturally occurring immune inhibitory signals have led to recent research aimed at exploiting these pathways to induce peripheral tolerance to alloantigen. Furthermore, we discuss new approaches to the induction of donor-specific tolerance by induction of molecular chimerism and the transfer of alloantigen-expressing mature T cells.

Regulation of T Cell Differentiation and Alloimmunity by the Cyclin-Dependent Kinase Inhibitor p18ink4c

PubMed Central

Rowell, Emily A.; Wang, Liqing; Chunder, Neelanjana; Hancock, Wayne W.; Wells, Andrew D.

2014-01-01

Cellular proliferation in response to mitogenic stimuli is negatively regulated by the Cip/Kip and the Ink4 families of cyclin-dependent kinase (CDK) inhibitors. Several of these proteins are elevated in anergic T cells, suggesting a potential role in the induction or maintenance of tolerance. Our previous studies showed that p27kip1 is required for the induction of T cell anergy and transplantation tolerance by costimulatory blockade, but a role for Ink4 proteins in these processes has not been established. Here we show that CD4+ T cells from mice genetically deficient for p18ink4c divide more rapidly than wild-type cells in response to antigenic, costimulatory and growth factor signals. However, this gain of proliferative function was accompanied by a moderate increase in the rate of cell death, and was accompanied by an overall defect in the generation of alloreactive IFNγ-producing effector cells. Consistent with this, p18ink4c-deficient T cells were unable to induce graft-vs-host disease in vivo, and p18ink4c deficiency cooperated with costimulatory blockade to significantly increase the survival of fully mismatched allografts in a cardiac transplantation model. While both p18ink4c and p27kip1 act to restrict T cell proliferation, p18ink4c exerts an opposite effect from p27kip1 on alloimmunity and organ transplant rejection, most likely by sustaining T cell survival and the development of effector function. Our studies point to additional important links between the cell cycle machinery and the processes of T cell differentiation, survival and tolerance. PMID:24614758

Plasmacytoid dendritic cells: no longer an enigma and now key to transplant tolerance?

PubMed Central

Rogers, NM; Isenberg, JS; Thomson, AW

2014-01-01

Plasmacytoid (p) dendritic cells (DC) are a specialized subset of DC whose primary role was initially defined by the production of type I interferons in response to viral infection. They are now known to also possess a repertoire of functions capable of determining T cell fate and activation. Under homeostatic conditions, non-lymphoid tissue-resident pDC play a critical role in the regulation of mucosal immunity, as well as the development of central and peripheral tolerance. Although these cells display a number of characteristics that differ from conventional DC, particularly altered costimulatory molecule expression and poor allostimulatory capacity when interacting with T cells, this phenotype favors the generation of alloantigen-specific regulatory CD4+ or CD8+ T cells critical to the development of graft tolerance. In this minireview we discuss pDC ontogeny, functional biology and the emerging data that demonstrate the importance of pDC in the induction of tolerance, as well as recent studies that define mechanisms underlying pDC-mediated tolerance to both solid organ and hematopoietic stem cell transplantats. We also highlight their use in clinical settings and the potential of pDC both as targets and cellular therapeutic agents to improve the outcome of organ transplantation. PMID:23617754

The regulatory T cell effector molecule fibrinogen-like protein 2 is necessary for the development of rapamycin-induced tolerance to fully MHC-mismatched murine cardiac allografts

PubMed Central

Urbanellis, Peter; Shyu, Wendy; Khattar, Ramzi; Wang, Jihong; Zakharova, Anna; He, Wei; Sadozai, Hassan; Amir, Achiya Z; Shalev, Itay; Phillips, M James; Adeyi, Oyedele; Ross, Heather; Grant, David; Levy, Gary A; Chruscinski, Andrzej

2015-01-01

Therapies that promote tolerance in solid organ transplantation will improve patient outcomes by eliminating the need for long-term immunosuppression. To investigate mechanisms of rapamycin-induced tolerance, C3H/HeJ mice were heterotopically transplanted with MHC-mismatched hearts from BALB/cJ mice and were monitored for rejection after a short course of rapamycin treatment. Mice that had received rapamycin developed tolerance with indefinite graft survival, whereas untreated mice all rejected their grafts within 9 days. In vitro, splenic mononuclear cells from tolerant mice maintained primary CD4+ and CD8+ immune responses to donor antigens consistent with a mechanism that involves active suppression of immune responses. Furthermore, infection with lymphocytic choriomeningitis virus strain WE led to loss of tolerance suggesting that tolerance could be overcome by infection. Rapamycin-induced, donor-specific tolerance was associated with an expansion of regulatory T (Treg) cells in both the spleen and allograft and elevated plasma levels of fibrinogen-like protein 2 (FGL2). Depletion of Treg cells with anti-CD25 (PC61) and treatment with anti-FGL2 antibody both prevented tolerance induction. Tolerant allografts were populated with Treg cells that co-expressed FGL2 and FoxP3, whereas rejecting allografts and syngeneic grafts were nearly devoid of dual-staining cells. We examined the utility of an immunoregulatory gene panel to discriminate between tolerance and rejection. We observed that Treg-associated genes (foxp3, lag3, tgf-β and fgl2) had increased expression and pro-inflammatory genes (ifn-γ and gzmb) had decreased expression in tolerant compared with rejecting allografts. Taken together, these data strongly suggest that Treg cells expressing FGL2 mediate rapamycin-induced tolerance. Furthermore, a gene biomarker panel that includes fgl2 can distinguish between rejecting and tolerant grafts. PMID:24990517

Tolerance in liver transplantation: Biomarkers and clinical relevance

PubMed Central

Baroja-Mazo, Alberto; Revilla-Nuin, Beatriz; Parrilla, Pascual; Martínez-Alarcón, Laura; Ramírez, Pablo; Pons, José Antonio

2016-01-01

Transplantation is the optimal treatment for end-stage organ failure, and modern immunosuppression has allowed important progress in short-term outcomes. However, immunosuppression poorly influences chronic rejection and elicits chronic toxicity in current clinical practice. Thus, a major goal in transplantation is to understand and induce tolerance. It is well established that human regulatory T cells expressing the transcription factor FoxP3 play important roles in the maintenance of immunological self-tolerance and immune homeostasis. The major regulatory T cell subsets and mechanisms of expansion that are critical for induction and long-term maintenance of graft tolerance and survival are being actively investigated. Likewise, other immune cells, such as dendritic cells, monocyte/macrophages or natural killer cells, have been described as part of the process known as “operational tolerance”. However, translation of these results towards clinical practice needs solid tools to identify accurately and reliably patients who are going to be tolerant. In this way, a plethora of genetic and cellular biomarkers is raising and being validated worldwide in large multi-center clinical trials. Few of the studies performed so far have provided a detailed analysis of the impact of immunosuppression withdrawal on pre-existing complications derived from the long-term administration of immunosuppressive drugs and the side effects associated with them. The future of liver transplantation is aimed to develop new therapies which increase the actual low tolerant vs non-tolerant recipients ratio. PMID:27678350

The homologous HD-Zip I transcription factors HaHB1 and AtHB13 confer cold tolerance via the induction of pathogenesis-related and glucanase proteins.

PubMed

Cabello, Julieta V; Arce, Agustín L; Chan, Raquel L

2012-01-01

Plants deal with cold temperatures via different signal transduction pathways. The HD-Zip I homologous transcription factors HaHB1 from sunflower and AtHB13 from Arabidopsis were identified as playing a key role in such cold response. The expression patterns of both genes were analyzed indicating an up-regulation by low temperatures. When these genes were constitutively expressed in Arabidopsis, the transgenic plants showed similar phenotypes including cell membrane stabilization under freezing treatments and cold tolerance. An exploratory transcriptomic analysis of HaHB1 transgenic plants indicated that several transcripts encoding glucanases and chitinases were induced. Moreover, under freezing conditions some proteins accumulated in HaHB1 plants apoplasts and these extracts exerted antifreeze activity in vitro. Three genes encoding two glucanases and a chitinase were overexpressed in Arabidopsis and these plants were able to tolerate freezing temperatures. All the obtained transgenic plants exhibited cell membrane stabilization after a short freezing treatment. Finally, HaHB1 and AtHB13 were used to transiently transform sunflower and soybean leading to the up-regulation of HaHB1/AtHB13-target homologues thus indicating the conservation of cold response pathways. We propose that HaHB1 and AtHB13 are involved in plant cold tolerance via the induction of proteins able to stabilize cell membranes and inhibit ice growth. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

Intranasal immunization with heat shock protein 60 induces CD4(+) CD25(+) GARP(+) and type 1 regulatory T cells and inhibits early atherosclerosis.

PubMed

Zhong, Y; Tang, H; Wang, X; Zeng, Q; Liu, Y; Zhao, X I; Yu, K; Shi, H; Zhu, R; Mao, X

2016-03-01

Atherosclerosis is an autoimmune inflammatory disease involving both innate and adaptive immune mechanisms. Immune tolerance induction may have therapeutic potential for the suppression of atherosclerosis. Current interest is directed towards mucosal tolerance induction, especially nasal tolerance. Previous studies have shown that heat shock protein 60 (HSP60) is recognized as an important autoantigen in atherosclerosis, and nasal or oral HSP60 can induce tolerance and ameliorate atherosclerosis by inducing several subsets of regulatory T cells (Tregs ) such as latency-associated peptide (LAP)(+) and forkhead box transcription factor 3 (FoxP3)(+) Tregs. However, little is known regarding the detailed mechanisms of nasal tolerance. Here, we again investigated the impact of nasal HSP60 on atherosclerosis and the mechanisms underlying the anti-atherosclerosis responses. We found that nasal HSP60 caused a significant 33·6% reduction in plaque size at the aortic root in the early stages of atherosclerosis (P < 0·001). Notably, a significant increase in activated CD4(+) CD25(+) glycoprotein A repetitions predominant (GARP)(+) Tregs, type 1 Tregs (Tr1 cells), and CD4(+) CD25(+) FoxP3(+) Tregs, as well as a marked decrease in the numbers of type 1 and 17 T helper cells was detected in the spleens and cervical lymph nodes of HSP60-treated mice. Moreover, nasal HSP60 increases the production of transforming growth factor (TGF)-β and interleukin (IL)-10 and decreases the secretion of IFN-γ and IL-17. Interestingly, the atheroprotective role of nasal HSP60 treatment was abrogated partly by the neutralization of IL-10. Our findings show that nasal administration of HSP60 can attenuate atherosclerotic formation by inducing GARP(+) Tregs, Tr1 cells and FoxP3(+) Tregs, and that these Tregs maintain immune homeostasis by secreting IL-10 and TGF-β. © 2015 British Society for Immunology.

Tolerogenic dendritic cells inhibit antiphospholipid syndrome derived effector/memory CD4⁺ T cell response to β2GPI.

PubMed

Torres-Aguilar, Honorio; Blank, Miri; Kivity, Shaye; Misgav, Mudi; Luboshitz, Jacob; Pierangeli, Silvia S; Shoenfeld, Yehuda

2012-01-01

The importance of β(2)-glycoprotein I (β(2)GPI)-specific CD4(+) T cells in the development of pathogenic processes in patients with antiphospholipid syndrome (APS) and APS mouse models is well established. Therefore, our objective is to manipulate the β2GPI specific CD4(+) T cells using tolerogenic dendritic cells (tDCs) to induce tolerance. We aim to evaluate the capability of tDCs to induce antigen-specific tolerance in effector/memory T cells from patients with APS and to elucidate the involved mechanism. DCs and tDCs were produced from patients with APS peripheral-blood-monocytes, using specific cytokines. β(2)GPI-specific tolerance induction was investigated by coculturing control DC (cDC) or tDC, β(2)GPI-loaded, with autologous effector/memory T cells, evaluating the proliferative response, phenotype, cytokines secretion, viability and regulatory T cells. Human monocyte-derived DCs treated with interleukin (IL)-10 and transforming growth factor β-1 (10/TGF-DC) induced β(2)GPI-specific-unresponsiveness in effector/memory CD4(+) T cells (46.5% ± 26.0 less proliferation) in 16 of 20 analysed patients with APS, without affecting the proliferative response to an unrelated candidin. In five analysed patients, 10/TGF-DC-stimulated T cells acquired an IL-2(low)interferon γ(low)IL-10(high) cytokine profile, with just a propensity to express higher numbers of Foxp3(+)CTLA-4(+) cells, but with an evident suppressive ability. In four of 10 analysed patients, 10/TGF-DC-stimulated T cell hyporesponsiveness could not be reverted and showed higher percentages of late apoptosis, p<0.02. The inherent tolerance induction resistance of activated T cells present during the development of autoimmune diseases has delayed the application of tDC as an alternative therapy. This study highlights the 10/TGF-DC feasibility to induce antigen-specific unresponsiveness in autoreactive T cells generated in patients with APS by inducing apoptosis or T cells with regulatory abilities.

Induction of regulatory T cells: A role for probiotics and prebiotics to suppress autoimmunity.

PubMed

Dwivedi, Mitesh; Kumar, Prasant; Laddha, Naresh C; Kemp, E Helen

2016-04-01

Regulatory T cells (Tregs) are comprised of a heterogeneous population of cells that play a vital role in suppressing inflammation and maintaining immune tolerance. Given the crucial role of Tregs in maintaining immune homeostasis, it is probably not surprising that many microbial species and their metabolites have the potential to induce Tregs. There is now great interest in the therapeutic potential of probiotics and prebiotics based strategies for a range of autoimmune disorders. This review will summarise recent findings concerning the role of probiotics and prebiotics in induction of Tregs to ameliorate the autoimmune conditions. In addition, the article is focused to explain the different mechanisms of Treg induction and function by these probiotics and prebiotics, based on the available studies till date. The article further proposes that induction of Tregs by probiotics and prebiotics could lead to the development of new therapeutic approach towards curbing the autoimmune response and as an alternative to detrimental immunosuppressive drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

Stress-tolerance of baker's-yeast (Saccharomyces cerevisiae) cells: stress-protective molecules and genes involved in stress tolerance.

PubMed

Shima, Jun; Takagi, Hiroshi

2009-05-29

During the fermentation of dough and the production of baker's yeast (Saccharomyces cerevisiae), cells are exposed to numerous environmental stresses (baking-associated stresses) such as freeze-thaw, high sugar concentrations, air-drying and oxidative stresses. Cellular macromolecules, including proteins, nucleic acids and membranes, are seriously damaged under stress conditions, leading to the inhibition of cell growth, cell viability and fermentation. To avoid lethal damage, yeast cells need to acquire a variety of stress-tolerant mechanisms, for example the induction of stress proteins, the accumulation of stress protectants, changes in membrane composition and repression of translation, and by regulating the corresponding gene expression via stress-triggered signal-transduction pathways. Trehalose and proline are considered to be critical stress protectants, as is glycerol. It is known that these molecules are effective for providing protection against various types of environmental stresses. Modifications of the metabolic pathways of trehalose and proline by self-cloning methods have significantly increased tolerance to baking-associated stresses. To clarify which genes are required for stress tolerance, both a comprehensive phenomics analysis and a functional genomics analysis were carried out under stress conditions that simulated those occurring during the commercial baking process. These analyses indicated that many genes are involved in stress tolerance in yeast. In particular, it was suggested that vacuolar H+-ATPase plays important roles in yeast cells under stress conditions.

Mechanisms of Oral Tolerance.

PubMed

Tordesillas, Leticia; Berin, M Cecilia

2018-02-27

Oral tolerance is a state of systemic unresponsiveness that is the default response to food antigens in the gastrointestinal tract, although immune tolerance can also be induced by other routes, such as the skin or inhalation. Antigen can be acquired directly by intestinal phagocytes, or pass through enterocytes or goblet cell-associated passages prior to capture by dendritic cells (DCs) in the lamina propria. Mucin from goblet cells acts on DCs to render them more tolerogenic. A subset of regulatory DCs expressing CD103 is responsible for delivery of antigen to the draining lymph node and induction of Tregs. These DCs also imprint gastrointestinal homing capacity, allowing the recently primed Tregs to home back to the lamina propria where they interact with macrophages that produce IL-10 and expand. Tregs induced by dietary antigen include Foxp3 + Tregs and Foxp3 - Tregs. In addition to Tregs, T cell anergy can also contribute to oral tolerance. The microbiota plays a key role in the development of oral tolerance, through regulation of macrophages and innate lymphoid cells that contribute to the regulatory phenotype of gastrointestinal dendritic cells. Absence of microbiota is associated with a susceptibility to food allergy, while presence of Clostridia strains can suppress development of food allergy through enhancement of Tregs and intestinal barrier function. It is not clear if feeding of antigens can also induce true immune tolerance after a memory immune response has been generated, but mechanistic studies of oral immunotherapy trials demonstrate shared pathways in oral tolerance and oral immunotherapy, with a role for Tregs and anergy. An important role for IgA and IgG antibodies in development of immune tolerance is also supported by studies of oral tolerance in humans. The elucidation of key pathways in oral tolerance could identify new strategies to increase efficacy of immunotherapy treatments for food allergy.

Habituation of enterotoxigenic Staphylococcus aureus to Origanum vulgare L. essential oil does not induce direct-tolerance and cross-tolerance to salts and organic acids

PubMed Central

Tavares, Adassa Gama; do Monte, Daniel Farias Marinho; Albuquerque, Allan dos Reis; Sampaio, Fábio Correia; Magnani, Marciane; de Siqueira, José Pinto; de Souza, Evandro Leite

2015-01-01

Enterotoxigenic Staphylococcus aureus strains that were isolated from foods were investigated for their ability to develop direct-tolerance and cross-tolerance to sodium chloride (NaCl), potassium chloride (KCl), lactic acid (LA) and acetic acid (AA) after habituation in sublethal amounts (1/2 of the minimum inhibitory concentration - 1/2 MIC and 1/4 of the minimum inhibitory concentration - 1/4 MIC) of Origanum vulgare L. essential oil (OVEO). The habituation of S. aureus to 1/2 MIC and 1/4 MIC of OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by modulation of MIC values. Otherwise, exposing the strains to OVEO at sublethal concentrations maintained or increased the sensitivity of the cells to the tested stressing agents because the MIC values of OVEO, NaCl, KCl, LA and AA against the cells that were previously habituated to OVEO remained the same or decreased when compared with non-habituated cells. These data indicate that OVEO does not have an inductive effect on the acquisition of direct-tolerance or cross-tolerance in the tested enterotoxigenic strains of S. aureus to antimicrobial agents that are typically used in food preservation. PMID:26413067

In Utero Exposure to Exosomal and B-Cell Alloantigens Lessens Alloreactivity of Recipients' Lymphocytes Rather than Confers Allograft Tolerance.

PubMed

Chen, Jeng-Chang; Ou, Liang-Shiou; Chan, Cheng-Chi; Kuo, Ming-Ling; Tseng, Li-Yun; Chang, Hsueh-Ling

2018-01-01

According to actively acquired tolerance, antigen exposure before full immune development in fetal or early neonatal life will cause tolerance to this specific antigen. In this study, we aimed to examine whether allogeneic tolerance could be elicited by in utero exposure to surface MHC antigens of allogenic cells or soluble form of MHC exosomes. Gestational day 14 FVB/N fetuses were subjected to intraperitoneal injection of allogeneic major histocompatibility complex (MHC) exosomes or highly enriched B-cells. Postnatally, the recipients were examined for the immune responses to donor alloantigens by lymphocyte proliferative reactions and skin transplantation. In utero exposure to allogeneic MHC exosomes abolished the alloreactivity of recipients' lymphocytes to the alloantigens, but could not confer skin allograft tolerance. In utero transplantation of highly enriched allogeneic B-cells generated low-level B-cell chimerism in the recipients. However, it only extended the survivals of skin allograft by a few days despite the lack of donor-specific alloreactivity of recipients' lymphocyte. Thus, an early in utero contact with exosomal or B-cell alloantigens did not lead to full skin tolerance but rather, at best, only to delayed skin rejection in the presence of microchimerism made by B-cell inocula. These results argued against the theory of actively acquired tolerance, and implicated that in utero exposure to marrow cells in previous studies was a unique model of allo-tolerance induction that involved the establishment of significant hematopoietic chimerism. Taken together with the discovery of in utero sensitization to ovalbumin in our previous studies, the immunological consequences of fetal exposure to foreign antigens might vary according to the type or nature of antigens introduced.

An Immunogenic Peptide in the A-box of HMGB1 Protein Reverses Apoptosis-induced Tolerance through RAGE Receptor*♦

PubMed Central

LeBlanc, Philippe M.; Doggett, Teresa Ann; Choi, Jayoung; Hancock, Mark A.; Durocher, Yves; Frank, Filipp; Nagar, Bhushan; Ferguson, Thomas A.; Saleh, Maya

2014-01-01

Apoptotic cells trigger immune tolerance in engulfing phagocytes. This poorly understood process is believed to contribute to the severe immunosuppression and increased susceptibility to nosocomial infections observed in critically ill sepsis patients. Extracellular high mobility group box 1 (HMGB1) is an important mediator of both sepsis lethality and the induction of immune tolerance by apoptotic cells. We have found that HMGB1 is sensitive to processing by caspase-1, resulting in the production of a fragment within its N-terminal DNA-binding domain (the A-box) that signals through the receptor for advanced glycation end products (RAGE) to reverse apoptosis-induced tolerance. In a two-hit mouse model of sepsis, we show that tolerance to a secondary infection and its associated mortality were effectively reversed by active immunization with dendritic cells treated with HMGB1 or the A-box fragment, but not a noncleavable form of HMGB1. These findings represent a novel link between caspase-1 and HMGB1, with potential therapeutic implications in infectious and inflammatory diseases. PMID:24474694

Mechanisms of allergen immunotherapy for inhaled allergens and predictive biomarkers.

PubMed

Shamji, Mohamed H; Durham, Stephen R

2017-12-01

Allergen immunotherapy is effective in patients with IgE-dependent allergic rhinitis and asthma. When immunotherapy is given continuously for 3 years, there is persistent clinical benefit for several years after its discontinuation. This disease-modifying effect is both antigen-specific and antigen-driven. Clinical improvement is accompanied by decreases in numbers of effector cells in target organs, including mast cells, basophils, eosinophils, and type 2 innate lymphoid cells. Immunotherapy results in the production of blocking IgG/IgG 4 antibodies that can inhibit IgE-dependent activation mediated through both high-affinity IgE receptors (FcεRI) on mast cells and basophils and low-affinity IgE receptors (FcεRII) on B cells. Suppression of T H 2 immunity can occur as a consequence of either deletion or anergy of antigen-specific T cells; induction of antigen-specific regulatory T cells; or immune deviation in favor of T H 1 responses. It is not clear whether the altered long-term memory resides within the T-cell or the B-cell compartment. Recent data highlight the role of IL-10-producing regulatory B cells and "protective" antibodies that likely contribute to long-term tolerance. Understanding mechanisms underlying induction and persistence of tolerance should identify predictive biomarkers of clinical response and discover novel and more effective strategies for immunotherapy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A pivotal role for galectin-1 in fetomaternal tolerance.

PubMed

Blois, Sandra M; Ilarregui, Juan M; Tometten, Mareike; Garcia, Mariana; Orsal, Arif S; Cordo-Russo, Rosalia; Toscano, Marta A; Bianco, Germán A; Kobelt, Peter; Handjiski, Bori; Tirado, Irene; Markert, Udo R; Klapp, Burghard F; Poirier, Francoise; Szekeres-Bartho, Julia; Rabinovich, Gabriel A; Arck, Petra C

2007-12-01

A successful pregnancy requires synchronized adaptation of maternal immune-endocrine mechanisms to the fetus. Here we show that galectin-1 (Gal-1), an immunoregulatory glycan-binding protein, has a pivotal role in conferring fetomaternal tolerance. Consistently with a marked decrease in Gal-1 expression during failing pregnancies, Gal-1-deficient (Lgals1-/-) mice showed higher rates of fetal loss compared to wild-type mice in allogeneic matings, whereas fetal survival was unaffected in syngeneic matings. Treatment with recombinant Gal-1 prevented fetal loss and restored tolerance through multiple mechanisms, including the induction of tolerogenic dendritic cells, which in turn promoted the expansion of interleukin-10 (IL-10)-secreting regulatory T cells in vivo. Accordingly, Gal-1's protective effects were abrogated in mice depleted of regulatory T cells or deficient in IL-10. In addition, we provide evidence for synergy between Gal-1 and progesterone in the maintenance of pregnancy. Thus, Gal-1 is a pivotal regulator of fetomaternal tolerance that has potential therapeutic implications in threatened pregnancies.

IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

PubMed

Tran, Giang T; Hodgkinson, Suzanne J; Carter, Nicole M; Verma, Nirupama D; Plain, Karren M; Boyd, Rochelle; Robinson, Catherine M; Nomura, Masaru; Killingsworth, Murray; Hall, Bruce M

2012-05-10

Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

Overcoming immunological barriers in regenerative medicine.

PubMed

Zakrzewski, Johannes L; van den Brink, Marcel R M; Hubbell, Jeffrey A

2014-08-01

Regenerative therapies that use allogeneic cells are likely to encounter immunological barriers similar to those that occur with transplantation of solid organs and allogeneic hematopoietic stem cells (HSCs). Decades of experience in clinical transplantation hold valuable lessons for regenerative medicine, offering approaches for developing tolerance-induction treatments relevant to cell therapies. Outside the field of solid-organ and allogeneic HSC transplantation, new strategies are emerging for controlling the immune response, such as methods based on biomaterials or mimicry of antigen-specific peripheral tolerance. Novel biomaterials can alter the behavior of cells in tissue-engineered constructs and can blunt host immune responses to cells and biomaterial scaffolds. Approaches to suppress autoreactive immune cells may also be useful in regenerative medicine. The most innovative solutions will be developed through closer collaboration among stem cell biologists, transplantation immunologists and materials scientists.

INDUCTION OF IMMUNOLOGIC TOLERANCE IN OLDER NEW ZEALAND MICE REPOPULATED WITH YOUNG SPLEEN, BONE MARROW, OR THYMUS

PubMed Central

Staples, Parker J.; Steinberg, Alfred D.; Talal, Norman

1970-01-01

Newborn, 7–9 day, and 16–18 day old NZB and B/W mice were, unlike older New Zealand mice, rendered tolerant to single doses of 8–10 mg of soluble BGG. After challenge, this tolerance was of short duration and escape occurred rapidly. Age-matched and similarly treated C3H, Balb/c and C57Bl mice did not escape from tolerance. Partial tolerance could be maintained by repeated injections of BGG. Biofiltration ruled out hyperphagocytosis as an explanation for this resistance to tolerance. Tolerance could be induced in older B/W mice if they were thymectomized, irradiated, and repopulated with young (12–15 day), but not old (2–3 month), spleen or bone marrow cells. Old bone marrow cells gave a non-tolerant response even when combined with young thymic grafts. Young bone marrow gave a tolerant response which was followed by the expected rapid escape only if a young thymus graft was also present. Escape was retarded if old thymus, or old irradiated thymus, was combined with young bone marrow. These results are best explained by abnormalities of both lymphoid precursors and thymic regulation. PMID:4192570

Overcoming food allergy through acquired tolerance conferred by transfer of Tregs in a murine model.

PubMed

Yamashita, H; Takahashi, K; Tanaka, H; Nagai, H; Inagaki, N

2012-02-01

The number of food allergy patients is increasing. Some children outgrow their food allergies through tolerance, whereas others remain susceptible throughout their lives. We aimed to contribute to food allergy therapeutics by understanding induction of oral tolerance in a murine food allergy model. We modified an existing murine food allergy model by using ovalbumin (OVA) to induce oral tolerance, either by pretreating mice with OVA or by transferring mesenteric lymph node (MLN) cells or T cells derived from mice treated with OVA. Pretreatment with OVA prevented food allergy, with complete suppression of OVA-specific immunoglobulin (Ig)E and IgA antibody production and interleukin (IL)-4, IL-10, and IL-9 mRNA expression. The proportion of regulatory T cells (Tregs) in MLN cells and expression of transforming growth factor-β mRNA increased. In the transfer model, anaphylaxis secondary to OVA intake was suppressed by transfer of whole MLN cells and Tregs from OVA-treated mice. However, OVA-specific IgE and IgA expressions were partially attenuated by transfer of antigen-specific and nonspecific Tregs, but not by whole MLN cells from OVA-treated mice. In the Treg transfer model, IL-4 and IL-10 mRNA expression decreased, but IL-9 mRNA expression increased. We concluded that oral tolerance for food antigens is induced in two ways: (i) by initial exposure to antigen, or inherent tolerance, and (ii) by transfer of Tregs, or acquired tolerance. Because food allergies occur when inherent tolerance is absent, understanding of acquired tolerance is important for the development of therapies for food allergy. © 2011 John Wiley & Sons A/S.

Regulatory T cells: present facts and future hopes.

PubMed

Becker, Christian; Stoll, Sabine; Bopp, Tobias; Schmitt, Edgar; Jonuleit, Helmut

2006-09-01

Naturally occurring CD4(+)CD25(+)Foxp3(+) regulatory T cells and several subsets of induced suppressor T cells are key players of the immune tolerance network and control the induction and effector phase of our immunological defense system. These T cell populations actively control the properties of other immune cells by suppressing their functional activity to prevent autoimmunity and transplant rejection but also influence the immune response to allergens as well as against tumor cells and pathogens. Even though we are far from completely understanding the molecular and cellular mechanisms that manage the different regulatory T cell populations, increasing evidence exists about their functional importance. The knowledge on their induction and activation opens the possibility for their selective manipulation in vivo as an attractive approach for an immunotherapy of unwanted immune responses. This review summarizes this knowledge and discusses the potential of regulatory T cells for novel immunointervention strategies in the future.

Mannose receptor induces T-cell tolerance via inhibition of CD45 and up-regulation of CTLA-4

PubMed Central

Schuette, Verena; Embgenbroich, Maria; Ulas, Thomas; Welz, Meike; Schulte-Schrepping, Jonas; Draffehn, Astrid M.; Quast, Thomas; Koch, Katharina; Nehring, Melanie; König, Jessica; Zweynert, Annegret; Harms, Frederike L.; Steiner, Nancy; Limmer, Andreas; Förster, Irmgard; Berberich-Siebelt, Friederike; Knolle, Percy A.; Wohlleber, Dirk; Kolanus, Waldemar; Beyer, Marc; Schultze, Joachim L.; Burgdorf, Sven

2016-01-01

The mannose receptor (MR) is an endocytic receptor involved in serum homeostasis and antigen presentation. Here, we identify the MR as a direct regulator of CD8+ T-cell activity. We demonstrate that MR expression on dendritic cells (DCs) impaired T-cell cytotoxicity in vitro and in vivo. This regulatory effect of the MR was mediated by a direct interaction with CD45 on the T cell, inhibiting its phosphatase activity, which resulted in up-regulation of cytotoxic T-lymphocyte–associated Protein 4 (CTLA-4) and the induction of T-cell tolerance. Inhibition of CD45 prevented expression of B-cell lymphoma 6 (Bcl-6), a transcriptional inhibitor that directly bound the CTLA-4 promoter and regulated its activity. These data demonstrate that endocytic receptors expressed on DCs contribute to the regulation of T-cell functionality. PMID:27601670

Mannose receptor induces T-cell tolerance via inhibition of CD45 and up-regulation of CTLA-4.

PubMed

Schuette, Verena; Embgenbroich, Maria; Ulas, Thomas; Welz, Meike; Schulte-Schrepping, Jonas; Draffehn, Astrid M; Quast, Thomas; Koch, Katharina; Nehring, Melanie; König, Jessica; Zweynert, Annegret; Harms, Frederike L; Steiner, Nancy; Limmer, Andreas; Förster, Irmgard; Berberich-Siebelt, Friederike; Knolle, Percy A; Wohlleber, Dirk; Kolanus, Waldemar; Beyer, Marc; Schultze, Joachim L; Burgdorf, Sven

2016-09-20

The mannose receptor (MR) is an endocytic receptor involved in serum homeostasis and antigen presentation. Here, we identify the MR as a direct regulator of CD8(+) T-cell activity. We demonstrate that MR expression on dendritic cells (DCs) impaired T-cell cytotoxicity in vitro and in vivo. This regulatory effect of the MR was mediated by a direct interaction with CD45 on the T cell, inhibiting its phosphatase activity, which resulted in up-regulation of cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4) and the induction of T-cell tolerance. Inhibition of CD45 prevented expression of B-cell lymphoma 6 (Bcl-6), a transcriptional inhibitor that directly bound the CTLA-4 promoter and regulated its activity. These data demonstrate that endocytic receptors expressed on DCs contribute to the regulation of T-cell functionality.

Active suppression induced by repetitive self-epitopes protects against EAE development.

PubMed

Puentes, Fabiola; Dickhaut, Katharina; Hofstätter, Maria; Falk, Kirsten; Rötzschke, Olaf

2013-01-01

Autoimmune diseases result from a breakdown in self-tolerance to autoantigens. Self-tolerance is induced and sustained by central and peripheral mechanisms intended to deviate harmful immune responses and to maintain homeostasis, where regulatory T cells play a crucial role. The use of self-antigens in the study and treatment of a range of autoimmune diseases has been widely described; however, the mechanisms underlying the induced protection by these means are unclear. This study shows that protection of experimental autoimmune disease induced by T cell self-epitopes in a multimerized form (oligomers) is mediated by the induction of active suppression. The experimental autoimmune encephalomyelitis (EAE) animal model for multiple sclerosis was used to study the mechanisms of protection induced by the treatment of oligomerized T cell epitope of myelin proteolipid protein (PLP139-151). Disease protection attained by the administration of oligomers was shown to be antigen specific and effective in both prevention and treatment of ongoing EAE. Oligomer mediated tolerance was actively transferred by cells from treated mice into adoptive hosts. The induction of active suppression was correlated with the recruitment of cells in the periphery associated with increased production of IL-10 and reduction of the pro-inflammatory cytokine TNF-α. The role of suppressive cytokines was demonstrated by the reversion of oligomer-induced protection after in vivo blocking of either IL-10 or TGF-β cytokines. This study strongly supports an immunosuppressive role of repeat auto-antigens to control the development of EAE with potential applications in vaccination and antigen specific treatment of autoimmune diseases.

Accumulation of 19-kDa plasma membrane polypeptide during induction of freezing tolerance in wheat suspension-cultured cells by abscisic acid.

PubMed

Koike, M; Takezawa, D; Arakawa, K; Yoshida, S

1997-06-01

Suspension-cultured cells derived from immature embryos of winter wheat (Triticum aestivum L. cv. Chihoku) were used in experiments designed to obtain clues to the mechanism of the ABA-induced development of freezing tolerance. Cultured cells treated with 50 microM ABA for 5 d at 23 degrees C acquired the maximum level of freezing tolerance (LT50; -21.6 degrees C). The increased freezing tolerance of ABA-treated cells was closely associated with the remarkable accumulation of 19-kDa polypeptides in the plasma membrane. The 19-kDa polypeptide components were isolated by preparative gel electrophoresis and were further separated into one major (AWPM-19) and other minor polypeptide components by Tricine-SDS-PAGE. N-terminal amino acid sequence of AWPM-19 was determined, and a cDNA clone encoding AWPM-19 was isolated by PCR from the library prepared from the ABA-treated cultured cells. The cDNA clone (WPM-1) encoded a 18.9 kDa hydrophobic polypeptide with four putative membrane spanning domains and with a high pI value (10.2). Expression of WPM-1 mRNA was dramatically induced by 50 microM ABA within a few hours. These results suggest that the AWPM-19 might be closely associated with the ABA-induced increase in freezing tolerance in wheat cultured cells.

Recombinant Lactococcus lactis can make the difference in antigen-specific immune tolerance induction, the Type 1 Diabetes case

PubMed Central

2014-01-01

Especially in western civilizations, immune diseases that are driven by innocuous (auto- or allo-) antigens are gradually evolving to become pandemic threats. A particularly poignant example is type 1 diabetes, where young children are confronted with the perspective and consequences of total pancreatic β-cell destruction. Along these disquieting observations we find ourselves equipped with impressively accumulating molecular immunological knowledge on the ins and outs of these pathologies. Often, however, it is difficult to translate this wealth into efficacious medicines. The molecular understanding, the concept of oral tolerance induction, the benefit of using recombinant Lactococcus lactis therein and recent openings towards their clinical use may well enable turning all colors to their appropriate fields on this Rubik's cube. PMID:25185797

Tolerance in Kidney Transplantation: What Is on the B Side?

PubMed Central

Borràs, Francesc E.

2016-01-01

Regulatory B cells (Breg) are in the spotlight for their role in immune homeostasis maintenance and tolerance achievement as in the last years the correlation with functional and increased Breg numbers in autoimmune diseases and transplantation has been extensively proven. Their study is, however, in its infancy with still little knowledge and consensus on their origin, phenotype, and mechanism of action. All this hampers the pursuit of an effective Breg induction method for therapeutic purposes. In this review we aim to summarize the studies on human Breg and their implication in kidney transplantation and to further discuss the issues surrounding therapeutic applications of this cell subset. PMID:27956762

The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools.

PubMed

Madadkar Haghjou, Maryam; Colville, Louise; Smirnoff, Nicholas

2014-11-01

The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Network Topologies and Dynamics Leading to Endotoxin Tolerance and Priming in Innate Immune Cells

NASA Astrophysics Data System (ADS)

Fu, Yan; Glaros, Trevor; Zhu, Meng; Wang, Ping; Wu, Zhanghan; Tyson, John; Li, Liwu; Xing, Jianhua

2012-01-01

The innate immune system, acting as the first line of host defense, senses and adapts to foreign challenges through complex intracellular and intercellular signaling networks. Endotoxin tolerance and priming elicited by macrophages are classic examples of the complex adaptation of innate immune cells. Upon repetitive exposures to different doses of bacterial endotoxin (lipopolysaccharide) or other stimulants, macrophages show either suppressed or augmented inflammatory responses compared to a single exposure to the stimulant. Endotoxin tolerance and priming are critically involved in both immune homeostasis and the pathogenesis of diverse inflammatory diseases. However, the underlying molecular mechanisms are not well understood. By means of a computational search through the parameter space of a coarse-grained three-node network with a two-stage Metropolis sampling approach, we enumerated all the network topologies that can generate priming or tolerance. We discovered three major mechanisms for priming (pathway synergy, suppressor deactivation, activator induction) and one for tolerance (inhibitor persistence). These results not only explain existing experimental observations, but also reveal intriguing test scenarios for future experimental studies to clarify mechanisms of endotoxin priming and tolerance.

Artificial sweeteners and mixture of food additives cause to break oral tolerance and induce food allergy in murine oral tolerance model for food allergy.

PubMed

Yamashita, H; Matsuhara, H; Miotani, S; Sako, Y; Matsui, T; Tanaka, H; Inagaki, N

2017-09-01

Processed foods are part of daily life. Almost all processed foods contain food additives such as sweeteners, preservatives and colourants. From childhood, it is difficult to avoid consuming food additives. It is thought that oral tolerance for food antigens is acquired during early life. If tolerance fails, adverse immune responses to food proteins may occur. We hypothesized that food additives prevent acquisition of oral tolerance and aimed to verify the safety of food additives. We induced experimental oral tolerance in mice for ovalbumin (OVA), a food antigen, by previous oral treatment with OVA before sensitization with OVA injections. Food additives were administered at the induction of oral tolerance, and food allergy was induced by repeated administration of OVA. Symptoms of food allergy were defined as a change in body temperature and allergic diarrhoea. Saccharin sodium and a mixture of food additives inhibited acquisition of oral tolerance. Hypothermia and allergic diarrhoea with elevation of OVA-specific IgE were induced in the murine model of oral tolerance. Analyses of antigen-presenting cells in mesenteric lymph nodes showed that food additives affected their manner of migration. Additionally, food additives decreased the proportion of CD25 hi regulatory T cells among CD4 + T cells in the mesenteric lymph nodes. A large amount of food additives may prevent acquisition of oral tolerance. Intake of food additives in early life may increase the risk of food allergies. © 2017 John Wiley & Sons Ltd.

The T cells specific for the carboxyl-terminal determinants of self (rat) heat-shock protein 65 escape tolerance induction and are involved in regulation of autoimmune arthritis.

PubMed

Durai, Malarvizhi; Gupta, Radhey S; Moudgil, Kamal D

2004-03-01

Immunization of Lewis rats with heat-killed Mycobacterium tuberculosis H37Ra leads to development of polyarthritis (adjuvant-induced arthritis; AA) that shares several features with human rheumatoid arthritis (RA). Immune response to the 65-kDa mycobacterial heat-shock protein (Bhsp65) is believed to be involved in induction of AA as well as in experimental modulation of this disease. However, the understanding of several critical aspects of the pathogenesis of AA in the Lewis rat has severely been hampered by the lack of information both regarding the level as well as epitope specificity of tolerance to the mammalian self (rat) homologue of Bhsp65, 65-kDa rat heat-shock protein (Rhsp65), and about the functional attributes of the T cell repertoire specific for this self protein. In this study, we established that tolerance to Rhsp65 in the Lewis rat is incomplete, and that the residual T cells primed upon challenge with this self hsp65 are disease regulating in nature. We also have defined the T cell epitopes in the C-terminal region within Rhsp65 that contribute predominantly to the immune reactivity as well as the AA-protective effect of this self protein. Furthermore, the T cells primed by peptides comprising these C-terminal determinants can be efficiently restimulated by the naturally generated epitopes from endogenous Rhsp65, suggesting that self hsp65 might also be involved in natural remission from acute AA. These novel first experimental insights into the self hsp65-directed regulatory T cell repertoire in AA would help develop better immunotherapeutic approaches for autoimmune arthritis.

Membrane-bound Dickkopf-1 in Foxp3+ regulatory T cells suppresses T-cell-mediated autoimmune colitis.

PubMed

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.

A moderate decrease in temperature induces COR15a expression through the CBF signaling cascade and enhances freezing tolerance.

PubMed

Wang, Yi; Hua, Jian

2009-10-01

Temperature has a profound effect on plant growth and development. However, the molecular mechanisms underlying this regulation are not well understood. In particular, how moderate temperature variations are perceived and transduced inside the plant cells remains obscure. In this study, we analyzed transcriptional responses to a moderate decrease in temperature (cooling) in Arabidopsis thaliana. The cooling response involves a weaker and more transient induction of cold-induced genes, such as COR15a, than cold response. This induction probably accounts for the increase in freezing tolerance by cooling acclimation. Cooling also induces some defense response genes, and their induction, but not that of COR15a, requires the salicylic acid signaling pathway. Analysis of the regulation of COR15a reveals that cooling induction is mediated through the same C repeat/dehydration-responsive (CRT/DRE) element as cold induction. Furthermore, we identified a role for CBF1 and CBF4 in transducing signals of moderate decreases in temperature. It appears that variants of the CBF signaling cascade are utilized in cold and cooling responses, and a moderate decrease in temperature may invoke an adaptive response to prepare plants to cope with a more drastic decrease in temperature.

Naturally occurring tolerance acquisition to foods in previously allergic children is characterized by antigen specificity and associated with increased subsets of regulatory T cells.

PubMed

Qamar, N; Fishbein, A B; Erickson, K A; Cai, M; Szychlinski, C; Bryce, P J; Schleimer, R P; Fuleihan, R L; Singh, A M

2015-11-01

Food allergy affects approximately 6-8% of children, and increasing in prevalence. Some children naturally outgrow their food allergy without intervention, but the mechanisms by which this occurs remain poorly understood. We sought to investigate the role of regulatory T cells in the development of naturally acquired tolerance. Fifty-eight children (1-18 years) with either egg or peanut allergy, recent acquisition of natural tolerance to egg or peanut, or no food allergy were studied. Peripheral blood mononuclear cells (PBMC) from these groups were stimulated with relevant antigen for 48 h and flow cytometry performed to characterize both surface (CD3, CD4, CD25, CD14, CD19, and CD127) and intracellular markers (IL-10, Foxp3, and IL-5). Resting PBMC from naturally tolerant patients had significantly increased CD3+CD4+CD25+CD127loFoxp3+ cells, when compared to allergic or control patients (mean 6.36 vs. 2.37 vs. 2.62%, respectively, P < 0.05). Upon stimulation with relevant antigen, naturally tolerant patients also had increased IL-10-expressing CD25+CD127lo cells (6.33 vs. 1.65 vs. 0.7, P < 0.01), Foxp3+ cells (mean 12.6 vs. 5.42 vs. 3%, P < 0.01), and CD4+ cells (mean 4.48 vs. 1.59 vs. 0.87%, P < 0.01); the increase was not observed in PBMCs from allergic or control patients. Additionally, this upregulation was only seen with relevant antigen stimulation and not upon stimulation with unrelated antigen. The increased CD3+CD4+CD25+CD127lo cells at baseline and upon stimulation and increased induction of IL-10-producing cells of several types, including Tr1 cells, from naturally tolerant patients suggests an important role for regulatory T cell subsets in the acquisition of natural tolerance. © 2015 John Wiley & Sons Ltd.

Naturally Occurring Tolerance Acquisition to Foods in Previously Allergic Children is Characterized by Antigen Specificity and Associated with Increased Subsets of Regulatory T cells

PubMed Central

Qamar, Nashmia; Fishbein, Anna B.; Erickson, Kristin A.; Cai, Miao; Szychlinski, Christine; Bryce, Paul J.; Schleimer, Robert P.; Fuleihan, Ramsay L.; Singh, Anne Marie

2015-01-01

Background Food allergy affects approximately 6–8% of children, and increasing in prevalence. Some children naturally outgrow their food allergy without intervention but the mechanisms by which this occurs remain poorly understood. We sought to investigate the role of regulatory T cells in the development of naturally acquired tolerance. Methods Fifty-eight children (1 to 18 years) with either egg or peanut allergy, recent acquisition of natural tolerance to egg or peanut, or no food allergy were studied. Peripheral blood mononuclear cells (PBMC) from these groups were stimulated with relevant antigen for 48 hours and flow cytometry performed to characterize both surface (CD3, CD4, CD25, CD14, CD19, CD127) and intracellular markers (IL-10, Foxp3, and IL-5). Results Resting PBMC from naturally tolerant patients had significantly increased CD3+CD4+CD25+CD127loFoxp3+ cells, when compared to allergic or control patients [mean 6.36 vs 2.37 vs 2.62%, respectively, p<0.05]. Upon stimulation with relevant antigen, naturally tolerant patients also had increased IL-10-expressing CD25+CD127lo cells [6.33 vs 1.65 vs 0.7, p<0.01], Foxp3+ cells [mean 12.6 vs 5.42 vs 3%, p<0.01] and CD4+ cells [mean 4.48 vs 1.59 vs 0.87%, p<0.01]; the increase was not observed in PBMCs from allergic or control patients. Additionally, this upregulation was only seen with relevant antigen stimulation and not upon stimulation with unrelated antigen. Conclusion The increased CD3+CD4+CD25+CD127lo cells at baseline and upon stimulation and increased induction of IL-10-producing cells of several types, including Tr1 cells, from naturally tolerant patients suggests an important role for regulatory T cell subsets in the acquisition of natural tolerance. PMID:25989379

Tolerance of dormant and active cells in Pseudomonas aeruginosa PA01 biofilm to antimicrobial agents.

PubMed

Kim, Jaeeun; Hahn, Ji-Sook; Franklin, Michael J; Stewart, Philip S; Yoon, Jeyong

2009-01-01

The aim of the study was to determine the susceptibility of active and dormant cell populations from Pseudomonas aeruginosa biofilms to non-antibiotic antimicrobial agents such as chlorine, hydrogen peroxide and silver ions in comparison with antibiotics. Active cells in colony biofilm were differentially labelled by induction of a green fluorescent protein (GFP). Active and dormant cells were sorted in phosphate buffered solution by flow cytometry. Reductions in viability were determined with plate counts. The spatial pattern of metabolic activity in colony biofilm was verified, and the active and dormant cells were successfully sorted according to the GFP intensity. Active cells had bigger cell size and higher intracellular density than dormant cells. While dormant cells were more tolerant to tobramycin and silver ions, active cells were more tolerant to chlorine. Metabolically active cells contain denser intracellular components that can react with highly reactive oxidants such as chlorine, thereby reducing the available concentrations of chlorine. In contrast, the concentrations of silver ions and hydrogen peroxide were constant during treatment. Aerobically grown stationary cells were significantly more tolerant to chlorine unlike other antimicrobial agents. Chlorine was more effective in inactivation of metabolically inactive dormant cells and also more effective under anaerobic conditions. The high oxidative reactivity and rapid decay of chlorine might influence the different antimicrobial actions of chlorine compared with antibiotics. This study contributes to understanding the effects of dormancy and the presence of oxygen on the susceptibility of P. aeruginosa biofilm to a wide range of antimicrobial agents.

B lymphocytes confer immune tolerance via cell surface GARP-TGF-β complex.

PubMed

Wallace, Caroline H; Wu, Bill X; Salem, Mohammad; Ansa-Addo, Ephraim A; Metelli, Alessandra; Sun, Shaoli; Gilkeson, Gary; Shlomchik, Mark J; Liu, Bei; Li, Zihai

2018-04-05

GARP, a cell surface docking receptor for binding and activating latent TGF-β, is highly expressed by platelets and activated Tregs. While GARP is implicated in immune invasion in cancer, the roles of the GARP-TGF-β axis in systemic autoimmune diseases are unknown. Although B cells do not express GARP at baseline, we found that the GARP-TGF-β complex is induced on activated human and mouse B cells by ligands for multiple TLRs, including TLR4, TLR7, and TLR9. GARP overexpression on B cells inhibited their proliferation, induced IgA class-switching, and dampened T cell-independent antibody production. In contrast, B cell-specific deletion of GARP-encoding gene Lrrc32 in mice led to development of systemic autoimmune diseases spontaneously as well as worsening of pristane-induced lupus-like disease. Canonical TGF-β signaling more readily upregulates GARP in Peyer patch B cells than in splenic B cells. Furthermore, we demonstrated that B cells are required for the induction of oral tolerance of T cell-dependent antigens via GARP. Our studies reveal for the first time to our knowledge that cell surface GARP-TGF-β is an important checkpoint for regulating B cell peripheral tolerance, highlighting a mechanism of autoimmune disease pathogenesis.

Sodium chloride inhibits the suppressive function of FOXP3+ regulatory T cells.

PubMed

Hernandez, Amanda L; Kitz, Alexandra; Wu, Chuan; Lowther, Daniel E; Rodriguez, Donald M; Vudattu, Nalini; Deng, Songyan; Herold, Kevan C; Kuchroo, Vijay K; Kleinewietfeld, Markus; Hafler, David A

2015-11-02

FOXP3+ Tregs are central for the maintenance of self-tolerance and can be defective in autoimmunity. In multiple sclerosis and type-1 diabetes, dysfunctional self-tolerance is partially mediated by a population of IFNγ-secreting Tregs. It was previously reported that increased NaCl concentrations promote the induction of proinflammatory Th17 cells and that high-salt diets exacerbate experimental models of autoimmunity. Here, we have shown that increasing NaCl, either in vitro or in murine models via diet, markedly impairs Treg function. NaCl increased IFNγ secretion in Tregs, and reducing IFNγ - either by neutralization with anti-IFNγ antibodies or shRNA-mediated knockdown - restored suppressive activity in Tregs. The heightened IFNγ secretion and loss of Treg function were mediated by the serum/glucocorticoid-regulated kinase (SGK1). A high-salt diet also impaired human Treg function and was associated with the induction of IFNγ-secreting Tregs in a xenogeneic graft-versus-host disease model and in adoptive transfer models of experimental colitis. Our results demonstrate a putative role for an environmental factor that promotes autoimmunity by inducing proinflammatory responses in CD4 effector cells and Treg pathways.

Rapamycin Monotherapy in Patients With Type 1 Diabetes Modifies CD4+CD25+FOXP3+ Regulatory T-Cells

PubMed Central

Monti, Paolo; Scirpoli, Miriam; Maffi, Paola; Piemonti, Lorenzo; Secchi, Antonio; Bonifacio, Ezio; Roncarolo, Maria-Grazia; Battaglia, Manuela

2008-01-01

OBJECTIVE—Rapamycin is an immunosuppressive drug currently used to prevent graft rejection in humans, which is considered permissive for tolerance induction. Rapamycin allows expansion of both murine and human naturally occurring CD4+CD25+FOXP3+ T regulatory cells (nTregs), which are pivotal for the induction and maintenance of peripheral tolerance. Preclinical murine models have shown that rapamycin enhances nTreg proliferation and regulatory function also in vivo. Objective of this study was to assess whether rapamycin has in vivo effects on human nTregs. RESEARCH DESIGN AND METHODS—nTreg numbers and function were examined in a unique set of patients with type 1 diabetes who underwent rapamycin monotherapy before islet transplantation. RESULTS—We found that rapamycin monotherapy did not alter the frequency and functional features, namely proliferation and cytokine production, of circulating nTregs. However, nTregs isolated from type 1 diabetic patients under rapamycin treatment had an increased capability to suppress proliferation of CD4+CD25− effector T-cells compared with that before treatment. CONCLUSIONS—These findings demonstrate that rapamycin directly affects human nTreg function in vivo, which consists of refitting their suppressive activity, whereas it does not directly change effector T-cell function. PMID:18559659

Effect of ultrafine zinc oxide (ZnO) nanoparticles on induction of oral tolerance in mice.

PubMed

Matsumura, Misa; Takasu, Nobuo; Nagata, Masafumi; Nakamura, Kazuichi; Kawai, Motoyuki; Yoshino, Shin

2010-01-01

Ultrafine nanoparticles of zinc oxide (ZnO) recently became available as a substitute for larger-size fine ZnO particles. However, the biological activity of ultrafine ZnO currently remains undefined. In the present study, we investigated the effect of ultrafine ZnO on oral tolerance that plays an important role in the prevention of food allergy. Oral tolerance was induced in mice by a single oral administration (i.e., gavage) of 25 mg of ovalbumin (OVA) 5 days prior to a subcutaneous immunization with OVA (Day 0). Varying doses of ultrafine (diameter: approximately 21 nm) as well as fine (diameter: < 5 microm) ZnO particles were given orally at the same time during the OVA gavage. The results indicated that a single oral administration of OVA was followed by significant decreases in serum anti-OVA IgG, IgG(1), IgG(2a), and IgE antibodies and in the proliferative responses to the antigen by these hosts' spleen cells. The decreases in these immune responses to OVA were associated with a marked suppression of secretion of interferon (IFN)gamma, interleukin (IL)-5, and IL-17 by these lymphoid cells. Treatment with either ultrafine or fine ZnO failed to affect the oral OVA-induced suppression of antigen-specific IgG, IgG(1), IgG(2a), and IgE production or lymphoid cell proliferation. The suppression induced by the oral OVA upon secretion of IFN gamma, IL-5, and IL-17 was also unaffected by either size of ZnO. These results indicate that ultrafine particles of ZnO do not appear to modulate the induction of oral tolerance in mice.

How Escherichia coli Tolerates Profuse Hydrogen Peroxide Formation by a Catabolic Pathway

PubMed Central

Ravindra Kumar, Sripriya

2013-01-01

When Escherichia coli grows on conventional substrates, it continuously generates 10 to 15 μM/s intracellular H2O2 through the accidental autoxidation of redox enzymes. Dosimetric analyses indicate that scavenging enzymes barely keep this H2O2 below toxic levels. Therefore, it seemed potentially problematic that E. coli can synthesize a catabolic phenylethylamine oxidase that stoichiometrically generates H2O2. This study was undertaken to understand how E. coli tolerates the oxidative stress that must ensue. Measurements indicated that phenylethylamine-fed cells generate H2O2 at 30 times the rate of glucose-fed cells. Two tolerance mechanisms were identified. First, in enclosed laboratory cultures, growth on phenylethylamine triggered induction of the OxyR H2O2 stress response. Null mutants (ΔoxyR) that could not induce that response were unable to grow. This is the first demonstration that OxyR plays a role in protecting cells against endogenous H2O2. The critical element of the OxyR response was the induction of H2O2 scavenging enzymes, since mutants that lacked NADH peroxidase (Ahp) grew poorly, and those that additionally lacked catalase did not grow at all. Other OxyR-controlled genes were expendable. Second, phenylethylamine oxidase is an unusual catabolic enzyme in that it is localized in the periplasm. Calculations showed that when cells grow in an open environment, virtually all of the oxidase-generated H2O2 will diffuse across the outer membrane and be lost to the external world, rather than enter the cytoplasm where H2O2-sensitive enzymes are located. In this respect, the periplasmic compartmentalization of phenylethylamine oxidase serves the same purpose as the peroxisomal compartmentalization of oxidases in eukaryotic cells. PMID:23913322

How Escherichia coli tolerates profuse hydrogen peroxide formation by a catabolic pathway.

PubMed

Ravindra Kumar, Sripriya; Imlay, James A

2013-10-01

When Escherichia coli grows on conventional substrates, it continuously generates 10 to 15 μM/s intracellular H2O2 through the accidental autoxidation of redox enzymes. Dosimetric analyses indicate that scavenging enzymes barely keep this H2O2 below toxic levels. Therefore, it seemed potentially problematic that E. coli can synthesize a catabolic phenylethylamine oxidase that stoichiometrically generates H2O2. This study was undertaken to understand how E. coli tolerates the oxidative stress that must ensue. Measurements indicated that phenylethylamine-fed cells generate H2O2 at 30 times the rate of glucose-fed cells. Two tolerance mechanisms were identified. First, in enclosed laboratory cultures, growth on phenylethylamine triggered induction of the OxyR H2O2 stress response. Null mutants (ΔoxyR) that could not induce that response were unable to grow. This is the first demonstration that OxyR plays a role in protecting cells against endogenous H2O2. The critical element of the OxyR response was the induction of H2O2 scavenging enzymes, since mutants that lacked NADH peroxidase (Ahp) grew poorly, and those that additionally lacked catalase did not grow at all. Other OxyR-controlled genes were expendable. Second, phenylethylamine oxidase is an unusual catabolic enzyme in that it is localized in the periplasm. Calculations showed that when cells grow in an open environment, virtually all of the oxidase-generated H2O2 will diffuse across the outer membrane and be lost to the external world, rather than enter the cytoplasm where H2O2-sensitive enzymes are located. In this respect, the periplasmic compartmentalization of phenylethylamine oxidase serves the same purpose as the peroxisomal compartmentalization of oxidases in eukaryotic cells.

Induction of peripheral T cell tolerance and allo/xenoimmunity.

PubMed

Charpentier, B; Alard, P; Hiesse, C; Lantz, O

1994-03-01

It is theoretically impossible or at least difficult to tolerize animals in xenogeneic situation, particularly in non-concordant species. Both humoral defense and several cellular components (T and non T) are offensive weapons which can be directed at myriad of self-antigens in a normal situation, at allo-antigens in abnormal situations, at xeno-antigens in exceptional situations. In either cases, the fine epitopic definition of allo/xeno antigens seen by the TCR is far from being totally known. From recent studies showing the precise requirement of peptides assembly composition in the MHC class I and II groove it should be theoretically possible to tolerize any group of peptides if they are presented, some other, because not presented, may remain ignored, thus apparently tolerized. It is also know, that transplantation tolerance is not a law of "either nothing or all" but a multiple process depending of both the affinity of the TCR and the nature/compositions of the target. In view of the complex array of factors influencing the pathway of T cell activation, three forms of T cell non responsiveness may be suggested in the context of xenogeneic recognition: physical deletion of potentially reactive T cells occurring predominantly in the thymus, non reactivity of T cells resulting from their failure to be influenced by antigens, and anergy possibly due to inappropriate signals from non professional antigen presenting cells. Future investigations must elucidate the requirements for inducing these events in a purpose of xenogeneic organ transplantation.

Oral tolerance in neonates: from basics to potential prevention of allergic disease.

PubMed

Verhasselt, V

2010-07-01

Oral tolerance refers to the observation that prior feeding of an antigen induces local and systemic immune tolerance to that antigen. Physiologically, this process is probably of central importance for preventing inflammatory responses to the numerous dietary and microbial antigens present in the gut. Defective oral tolerance can lead to gut inflammatory disease, food allergies, and celiac disease. In the last two cases, the diseases develop early in life, stressing the necessity of understanding how oral tolerance is set up in neonates. This article reviews the parameters that have been outlined in adult animal models as necessary for tolerance induction and assesses whether these factors operate in neonates. In addition, we highlight the factors that are specific for this period of life and discuss how they could have an impact on oral tolerance. We pay particular attention to maternal influence on early oral tolerance induction through breast-feeding and outline the major parameters that could be modified to optimize tolerance induction in early life and possibly prevent allergic diseases.

From Tumor Immunosuppression to Eradication: Targeting Homing and Activity of Immune Effector Cells to Tumors

PubMed Central

Draghiciu, Oana; Nijman, Hans W.; Daemen, Toos

2011-01-01

Unraveling the mechanisms used by the immune system to fight cancer development is one of the most ambitious undertakings in immunology. Detailed knowledge regarding the mechanisms of induction of tolerance and immunosuppression within the tumor microenvironment will contribute to the development of highly effective tumor eradication strategies. Research within the last few decades has shed more light on the matter. This paper aims to give an overview on the current knowledge of the main tolerance and immunosuppression mechanisms elicited within the tumor microenvironment, with the focus on development of effective immunotherapeutic strategies to improve homing and activity of immune effector cells to tumors. PMID:22190971

Mercury intracellular partitioning and chelation in a salt marsh plant, Halimione portulacoides (L.) Aellen: strategies underlying tolerance in environmental exposure.

PubMed

Válega, M; Lima, A I G; Figueira, E M A P; Pereira, E; Pardal, M A; Duarte, A C

2009-01-01

In the presence of metal stress, plants can resort to a series of tolerance mechanisms. Therefore field studies should be undertaken in order to evaluate the real role of these mechanisms in stress coping. The aim of this paper was to clarify the biochemical processes behind mercury tolerance in Halimione portulacoides (L.) Aellen (Caryophyllales: Chenopodiaceae) collected in a mercury contaminated salt marsh. Different fractions of mercury were separated: buffer-soluble (mainly cytosolic) and insoluble mercury (mainly associated with membranes and cell walls). The amounts in each fraction of metal were compared and related to metal distribution within plant organs. Protein-mercury complexes were isolated and analysed for their thiol content in order to assess wether the tolerance of this salt marsh plant was associated with the induction of metal chelation by phytochelatins. Overall, the mercury tolerance strategies of the plant are likely to involve root cell wall immobilization as a major mechanism of metal resistance, rather than metal chelation in the cytosolic fraction. Nevertheless, phytochelatins were demonstrated to chelate mercury under environmental exposure.

Contribution of Hepatic Retinaldehyde Dehydrogenase Induction to Impairment of Glucose Metabolism by High-Fat Diet Feeding in C57BL/6J Mice.

PubMed

Xu, Jiong; Zhang, Mian; Zhang, Xiangping; Yang, Hanyu; Sun, Binbin; Wang, Zhongjian; Zhou, Yaqian; Wang, Shuting; Liu, Xiaodong; Liu, Li

2018-05-12

Obesity and insulin resistance are associated with overexpression of retinaldehyde dehydrogenase 1 (RALDH1). We aimed to investigate the roles of hepatic RALDH1 induction in glucose metabolism impairment using mice fed with high-fat diet (HFD). Mice were fed with HFD for 8 weeks and treated with RALDH inhibitor citral for another 4 weeks. Oral glucose tolerance test (OGTT), pyruvate tolerance test (PTT) and insulin tolerance test (ITT) were operated. Expressions of Phosphoenolpyruvate carboxykinase 1 (PCK1), glucokinase (GCK) and RALDH1 were measured. Therapeutic effects of citral were also conducted in diabetic rats. Effects of retinaldehyde on PCK1 and GCK expressions were examined in rat primary hepatocytes and HepG2 cells. The results showed that HFD mice were characterized by hyperlipidaemia and insulin resistance, accompanied by significantly increased RALDH1 activity and expression. Citral (10 and 50 mg/kg) ameliorated HFD-induced hyperlipidaemia and insulin resistance, as evidenced by the improved fasting glucose, insulin levels and lipid profiles. OGTT and PTT demonstrated that citral reversed HFD-induced glucose disposal impairment and glucose production enhancement. Citral also reversed the increased PCK1 expression and decreased GCK expression by HFD. Citral therapeutic effects were reconfirmed in diabetic rats. In vitro data indicated that retinaldehyde had the strongest PCK1 induction in primary hepatocytes of diabetic rats compared with HFD rats and control rats, in line with the increased RALDH1 expression. Citral reversed the retinaldehyde-induced PCK1 expression in primary rat hepatocytes and HepG2 cells. In conclusion, RALDH1 induction impaired glucose metabolism partly via modulating PCK1 and GCK expression. Citral improved glucose metabolism through inhibiting RALDH activity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

B lymphocytes confer immune tolerance via cell surface GARP-TGF-β complex

PubMed Central

Wallace, Caroline H.; Wu, Bill X.; Salem, Mohammad; Ansa-Addo, Ephraim A.; Metelli, Alessandra; Sun, Shaoli; Gilkeson, Gary; Shlomchik, Mark J.

2018-01-01

GARP, a cell surface docking receptor for binding and activating latent TGF-β, is highly expressed by platelets and activated Tregs. While GARP is implicated in immune invasion in cancer, the roles of the GARP-TGF-β axis in systemic autoimmune diseases are unknown. Although B cells do not express GARP at baseline, we found that the GARP-TGF-β complex is induced on activated human and mouse B cells by ligands for multiple TLRs, including TLR4, TLR7, and TLR9. GARP overexpression on B cells inhibited their proliferation, induced IgA class-switching, and dampened T cell–independent antibody production. In contrast, B cell–specific deletion of GARP-encoding gene Lrrc32 in mice led to development of systemic autoimmune diseases spontaneously as well as worsening of pristane-induced lupus-like disease. Canonical TGF-β signaling more readily upregulates GARP in Peyer patch B cells than in splenic B cells. Furthermore, we demonstrated that B cells are required for the induction of oral tolerance of T cell–dependent antigens via GARP. Our studies reveal for the first time to our knowledge that cell surface GARP-TGF-β is an important checkpoint for regulating B cell peripheral tolerance, highlighting a mechanism of autoimmune disease pathogenesis. PMID:29618665

Targeting Antigens to Dec-205 on Dendritic Cells Induces Immune Protection in Experimental Colitis in Mice

PubMed Central

Wadwa, Munisch; Klopfleisch, Robert; Buer, Jan; Westendorf, Astrid M.

2016-01-01

The endocytotic c-type lectin receptor DEC-205 is highly expressed on immature dendritic cells. In previous studies, it was shown that antigen-targeting to DEC-205 is a useful tool for the induction of antigen-specific Foxp3+ regulatory T cells and thereby can prevent inflammatory processes. However, whether this approach is sufficient to mediate tolerance in mucosal tissues like the gut is unknown. In this study, we established a new mouse model in which the adoptive transfer of naive hemagglutinin (HA)-specific CD4+Foxp3– T cells into VILLIN-HA transgenic mice leads to severe colitis. To analyze if antigen-targeting to DEC-205 could protect against inflammation of the gut, VILLIN-HA transgenic mice were injected with an antibody–antigen complex consisting of the immunogenic HA110–120 peptide coupled to an α-DEC-205 antibody (DEC-HA) before adoptive T cell transfer. DEC-HA-treated mice showed significantly less signs of intestinal inflammation as was demonstrated by reduced loss of body weight and histopathology in the gut. Strikingly, abrogated intestinal inflammation was mediated via the conversion of naive HA-specific CD4+Foxp3– T cells into HA-specific CD4+Foxp3+ regulatory T cells. In this study, we provide evidence that antigen-targeting to DEC-205 can be utilized for the induction of tolerance in mucosal organs that are confronted with large numbers of exogenous antigens. PMID:27141310

Genome-wide transcriptomic analysis of response to low temperature reveals candidate genes determining divergent cold-sensitivity of maize inbred lines.

PubMed

Sobkowiak, Alicja; Jończyk, Maciej; Jarochowska, Emilia; Biecek, Przemysław; Trzcinska-Danielewicz, Joanna; Leipner, Jörg; Fronk, Jan; Sowiński, Paweł

2014-06-01

Maize, despite being thermophyllic due to its tropical origin, demonstrates high intraspecific diversity in cold-tolerance. To search for molecular mechanisms of this diversity, transcriptomic response to cold was studied in two inbred lines of contrasting cold-tolerance. Microarray analysis was followed by extensive statistical elaboration of data, literature data mining, and gene ontology-based classification. The lines used had been bred earlier specifically for determination of QTLs for cold-performance of photosynthesis. This allowed direct comparison of present transcriptomic data with the earlier QTL mapping results. Cold-treated (14 h at 8/6 °C) maize seedlings of cold-tolerant ETH-DH7 and cold-sensitive ETH-DL3 lines at V3 stage showed strong, consistent response of the third leaf transcriptome: several thousand probes showed similar, statistically significant change in both lines, while only tens responded differently in the two lines. The most striking difference between the responses of the two lines to cold was the induction of expression of ca. twenty genes encoding membrane/cell wall proteins exclusively in the cold-tolerant ETH-DH7 line. The common response comprised mainly repression of numerous genes related to photosynthesis and induction of genes related to basic biological activity: transcription, regulation of gene expression, protein phosphorylation, cell wall organization. Among the genes showing differential response, several were close to the QTL regions identified in earlier studies with the same inbred lines and associated with biometrical, physiological or biochemical parameters. These transcripts, including two apparently non-protein-coding ones, are particularly attractive candidates for future studies on mechanisms determining divergent cold-tolerance of inbred maize lines.

Antigen-Specific Immune Modulation Targets mTORC1 Function To Drive Chemokine Receptor-Mediated T Cell Tolerance.

PubMed

Chen, Weirong; Wan, Xiaoxiao; Ukah, Tobechukwu K; Miller, Mindy M; Barik, Subhasis; Cattin-Roy, Alexis N; Zaghouani, Habib

2016-11-01

To contain autoimmunity, pathogenic T cells must be eliminated or diverted from reaching the target organ. Recently, we defined a novel form of T cell tolerance whereby treatment with Ag downregulates expression of the chemokine receptor CXCR3 and prevents diabetogenic Th1 cells from reaching the pancreas, leading to suppression of type 1 diabetes (T1D). This report defines the signaling events underlying Ag-induced chemokine receptor-mediated tolerance. Specifically, we show that the mammalian target of rapamycin complex 1 (mTORC1) is a major target for induction of CXCR3 downregulation and crippling of Th1 cells. Indeed, Ag administration induces upregulation of programmed death-ligand 1 on dendritic cells in a T cell-dependent manner. In return, programmed death-ligand 1 interacts with the constitutively expressed programmed death-1 on the target T cells and stimulates docking of Src homology 2 domain-containing tyrosine phosphatase 2 phosphatase to the cytoplasmic tail of programmed death-1. Active Src homology 2 domain-containing tyrosine phosphatase 2 impairs the signaling function of the PI3K/protein kinase B (AKT) pathway, leading to functional defect of mTORC1, downregulation of CXCR3 expression, and suppression of T1D. Thus, mTORC1 component of the metabolic pathway serves as a target for chemokine receptor-mediated T cell tolerance and suppression of T1D. Copyright © 2016 by The American Association of Immunologists, Inc.

Timing and Frequency of Sublethal Exposure Modifies the Induction and Retention of Increased Insecticide Tolerance in Wood Frogs (Lithobates sylvaticus).

PubMed

Jones, Devin K; Yates, Erika K; Mattes, Brian M; Hintz, William D; Schuler, Matthew S; Relyea, Rick A

2018-05-22

While the paradigm for increased tolerance to pesticides has been by selection on constitutive (naïve) traits, recent research has shown it can also occur through phenotypic plasticity. However, the time period in which induction can occur, the duration of induced tolerance, and the influence of multiple induction events remain unknown. We hypothesized that the induction of increased pesticide tolerance is limited to early sensitive periods, the magnitude of induced tolerance depends on the number of exposures, and the retention of induced tolerance depends on the time elapsed after an exposure and the number of exposures. To test these hypotheses, we exposed wood frog tadpoles to either a no-carbaryl control (water) or 0.5 mg/L carbaryl at four time periods, and later tested their tolerance to carbaryl using time-to-death assays. We discovered that tadpoles induced increased tolerance early and midway, but not late, in our experiment and their constitutive tolerance increased with age. We found no difference in the magnitude of induced tolerance following one or two exposures. Lastly, induced pesticide tolerance was reversed within 6 d, but was retained only when tadpoles experienced all four consecutive exposures. Phenotypic plasticity provides an immediate response for sensitive amphibian larvae to early pesticide exposures and reduces phenotypic mismatches in aquatic environments contaminated by agrochemicals. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Nanoparticle delivery of donor antigens for transplant tolerance in allogeneic islet transplantation.

PubMed

Bryant, Jane; Hlavaty, Kelan A; Zhang, Xiaomin; Yap, Woon-Teck; Zhang, Lei; Shea, Lonnie D; Luo, Xunrong

2014-10-01

Human islet cell transplantation is a promising treatment for type 1 diabetes; however, long-term donor-specific tolerance to islet allografts remains a clinically unmet goal. We have previously shown that recipient infusions of apoptotic donor splenocytes chemically treated with 1-ethyl-3-(3'-dimethylaminopropyl)-carbodiimide (donor ECDI-SP) can mediate long-term acceptance of full major histocompatibility complex (MHC)-mismatched murine islet allografts without the use of immunosuppression. In this report, we investigated the use of poly(lactide-co-glycolide) (PLG) particles in lieu of donor ECDI-SP as a synthetic, cell-free carrier for delivery of donor antigens for the induction of transplant tolerance in full MHC-mismatched murine allogeneic islet transplantation. Infusions of donor antigen-coupled PLG particles (PLG-dAg) mediated tolerance in ∼20% of recipient mice, and the distribution of cellular uptake of PLG-dAg within the spleen was similar to that of donor ECDI-SP. PLG-dAg mediated the contraction of indirectly activated T cells but did not modulate the direct pathway of allorecognition. Combination of PLG-dAg with a short course of low dose immunosuppressant rapamycin at the time of transplant significantly improved the tolerance efficacy to ∼60%. Furthermore, altering the timing of PLG-dAg administration to a schedule that is more feasible for clinical transplantation resulted in equal tolerance efficacy. Thus, the combination therapy of PLG-dAg infusions with peritransplant rapamycin represents a clinically attractive, biomaterials-based and cell-free method for inducing long-term donor-specific tolerance for allogeneic cell transplantation, such as for allogeneic islet transplantation. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Retrospective, Multicenter Study of the Tolerance of Induction Chemotherapy With Docetaxel, Cisplatin, and 5-Fluorouracil Followed by Radiotherapy With Concomitant Cetuximab in 46 Cases of Squamous Cell Carcinoma of the Head and Neck

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buiret, Guillaume, E-mail: guillaume.buiret@laposte.ne; Service de biostatistique, Hospices Civils de Lyon, Lyon; Combe, Claire

2010-06-01

Purpose: To investigate, in a multicenter study, the tolerance of induction chemotherapy (ICT) and external radiotherapy (ERT) with concomitant cetuximab in the treatment of patients with squamous cell carcinoma of the head and neck (SCCHN). Patients and Methods: Clinical data from 46 patients with Stage III or IV nonmetastatic SCCHN who received docetaxel, cisplatin, and 5-fluorouracil as ICT, followed by ERT with concomitant cetuximab, were retrospectively analyzed. Clinical safety (weight, allergy, mucositis, and dermatitis) and paraclinical safety (levels of hemoglobin, polynuclear neutrophils, and creatinine clearance) were studied. The primary objective was the proportion of patients who completed the protocol. Results:more » The percentage of patients completing ICT was 73.9%, ERT 93.5%, and cetuximab 69.6%. Induction chemotherapy was better tolerated than that previously reported. The rates of temporary suspensions of radiation (39.1%, mean duration of 13 days) and hospitalization (26.1%) during ERT with concomitant cetuximab were high. Weight loss during treatment (21.4% of patients lost >10% of their body weight), radiodermatitis, and radiomucositis were the main causes of temporary suspension of treatment, although Grade 4 dermatitis was not experienced. There were no allergic reactions to cetuximab. Conclusion: The completed protocol rate for SCCHN patients receiving ICT and ERT with concomitant cetuximab is high and the toxicity acceptable. Future improvements to protocol will be possible through early action and systematic implementation of nutritional support coupled with antibiotic treatment upon the first signs of radiodermatitis. These data could be useful for prospective studies on the safety and efficacy of this protocol.« less

Positive and Negative Regulatory Mechanisms for Fine-Tuning Cellularity and Functions of Medullary Thymic Epithelial Cells.

PubMed

Akiyama, Taishin; Tateishi, Ryosuke; Akiyama, Nobuko; Yoshinaga, Riko; Kobayashi, Tetsuya J

2015-01-01

Self-tolerant T cells and regulatory T cells develop in the thymus. A wide variety of cell-cell interactions in the thymus is required for the differentiation, proliferation, and repertoire selection of T cells. Various secreted and cell surface molecules expressed in thymic epithelial cells (TECs) mediate these processes. Moreover, cytokines expressed by cells of hematopoietic origin regulate the cellularity of TECs. Tumor necrosis factor (TNF) family RANK ligand, lymphotoxin, and CD40 ligand, expressed in T cells and innate lymphoid cells (ILCs), promote the differentiation and proliferation of medullary TECs (mTECs) that play critical roles in the induction of immune tolerance. A recent study suggests that interleukin-22 (IL-22) produced by ILCs promotes regeneration of TECs after irradiation. Intriguingly, tumor growth factor-β and osteoprotegerin limit cellularity of mTECs, thereby attenuating regulatory T cell generation. We will review recent insights into the molecular basis for cell-cell interactions regulating differentiation and proliferation of mTECs and also discuss about a perspective on use of mathematical models for understanding this complicated system.

Tolerance and chimerism.

PubMed

Kolb, Hans-Jochem; Guenther, Wolfgang; Gyurkocza, Boglarka; Hoetzl, Florian; Simoes, Belinda; Falk, Christine; Schleuning, Michael; Ledderose, Georg

2003-05-15

Stem-cell transplantation from human leukocyte antigen (HLA)-haploidentical family members carries a high risk of rejection and graft-versus-host disease (GVHD) if donor and recipient differ by more than one HLA antigen. The authors have developed treatment protocols from studies in dog leukocyte antigen-haploidentical dogs that prevent rejection and modify GVHD to the extent that patients with aggressive hematologic neoplasia can be treated with success. Principal improvements have been achieved in the use of cyclophosphamide and total-body irradiation for conditioning and T-cell depletion for prevention of GVHD. More recently, the combination of marrow and CD6-depleted mobilized donor blood cells (MDBC) has been introduced for HLA-haploidentical transplantation on the basis that CD6-depleted MDBC contain immunoregulatory cells besides stem cells and natural killer cells. Clinical results are reported on 36 patients with high-risk hematologic neoplasia. The results encourage the use of HLA-haploidentical stem-cell transplantation at an earlier stage of the disease. This method could also be of use for tolerance induction in organ transplantation.

Safety and tolerability of allogeneic dendritic cell vaccination with induction of Wilms tumor 1-specific T cells in a pediatric donor and pediatric patient with relapsed leukemia: a case report and review of the literature.

PubMed

Saito, Shoji; Yanagisawa, Ryu; Yoshikawa, Kentaro; Higuchi, Yumiko; Koya, Terutsugu; Yoshizawa, Kiyoshi; Tanaka, Miyuki; Sakashita, Kazuo; Kobayashi, Takashi; Kurata, Takashi; Hirabayashi, Koichi; Nakazawa, Yozo; Shiohara, Masaaki; Yonemitsu, Yoshikazu; Okamoto, Masato; Sugiyama, Haruo; Koike, Kenichi; Shimodaira, Shigetaka

2015-03-01

A 15-year-old girl with acute lymphoblastic leukemia received allogeneic dendritic cell vaccination, pulsed with Wilms tumor 1 (WT1) peptide, after her third hematopoietic stem cell transplantation (HSCT). The vaccines were generated from the third HSCT donor, who was her younger sister, age 12 years. The patient received 14 vaccines and had no graft-versus-host disease or systemic adverse effect, aside from grade 2 skin reaction at the injection site. WT1-specific immune responses were detected after vaccination by both WT1-tetramer analysis and enzyme-linked immunosorbent spot assay. This strategy may be safe, tolerable and even feasible for patients with a relapse after HSCT. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Tolerance induction of IgG+ memory B cells by T cell-independent type II antigens.

PubMed

Haniuda, Kei; Nojima, Takuya; Ohyama, Kyosuke; Kitamura, Daisuke

2011-05-15

Memory B cells generated during a T cell-dependent immune response rapidly respond to a secondary immunization by producing abundant IgG Abs that bind cognate Ag with high affinity. It is currently unclear whether this heightened recall response by memory B cells is due to augmented IgG-BCR signaling, which has only been demonstrated in the context of naive transgenic B cells. To address this question, we examined whether memory B cells can respond in vivo to Ags that stimulate only through BCR, namely T cell-independent type II (TI-II) Ags. In this study, we show that the TI-II Ag (4-hydroxy-3-nitrophenyl) acetyl (NP)-Ficoll cannot elicit the recall response in mice first immunized with the T cell-dependent Ag NP-chicken γ-globulin. Moreover, the NP-Ficoll challenge in vivo as well as in vitro significantly inhibits a subsequent recall response to NP-chicken γ-globulin in a B cell-intrinsic manner. This NP-Ficoll-mediated tolerance is caused by the preferential elimination of IgG(+) memory B cells binding to NP with high affinity. These data indicate that BCR cross-linking with a TI-II Ag does not activate IgG(+) memory B cells, but rather tolerizes them, identifying a terminal checkpoint of memory B cell differentiation that may prevent autoimmunity.

T cell ignorance is bliss: T cells are not tolerized by Langerhans cells presenting human papillomavirus antigens in the absence of costimulation.

PubMed

Woodham, Andrew W; Yan, Lisa; Skeate, Joseph G; van der Veen, Daniel; Brand, Heike H; Wong, Michael K; Da Silva, Diane M; Kast, W Martin

2016-12-01

Human papillomavirus type 16 (HPV16) infections are intra-epithelial, and thus, HPV16 is known to interact with Langerhans cells (LCs), the resident epithelial antigen-presenting cells (APCs). The current paradigm for APC-mediated induction of T cell anergy is through delivery of T cell receptor signals via peptides on MHC molecules (signal 1), but without costimulation (signal 2). We previously demonstrated that LCs exposed to HPV16 in vitro present HPV antigens to T cells without costimulation, but it remained uncertain if such T cells would remain ignorant, become anergic, or in the case of CD4+ T cells, differentiate into Tregs. Here we demonstrate that Tregs were not induced by LCs presenting only signal 1, and through a series of in vitro immunizations show that CD8 + T cells receiving signal 1 + 2 from LCs weeks after consistently receiving signal 1 are capable of robust effector functions. Importantly, this indicates that T cells are not tolerized but instead remain ignorant to HPV, and are activated given the proper signals.

T-cell selection and intestinal homeostasis

PubMed Central

Ai, Teresa L.; Solomon, Benjamin D.; Hsieh, Chyi-Song

2014-01-01

Summary Although intestinal bacteria live deep within the body, they are topographically on the exterior surface and thus outside the host. According to the classic notion that the immune system targets non-self rather than self, these intestinal bacteria should be considered foreign and therefore attacked and eliminated. While this appears to be true for some commensal bacterial species, recent data suggests that the immune system actively becomes tolerant to many bacterial organisms. The induction or activation of regulatory T (Treg) cells that inhibit, rather than promote, inflammatory responses to commensal bacteria appears to be a central component of mucosal tolerance. Loss of this mechanism can lead to inappropriate immune reactivity toward commensal organisms, perhaps contributing to mucosal inflammation characteristic of disorders such as inflammatory bowel disease. PMID:24712459

Disease-Associated Plasmacytoid Dendritic Cells

PubMed Central

Li, Shuang; Wu, Jing; Zhu, Shan; Liu, Yong-Jun; Chen, Jingtao

2017-01-01

Plasmacytoid dendritic cells (pDCs), also called natural interferon (IFN)-producing cells, represent a specialized cell type within the innate immune system. pDCs are specialized in sensing viral RNA and DNA by toll-like receptor-7 and -9 and have the ability to rapidly produce massive amounts of type 1 IFNs upon viral encounter. After producing type 1 IFNs, pDCs differentiate into professional antigen-presenting cells, which are capable of stimulating T cells of the adaptive immune system. Chronic activation of human pDCs by self-DNA or mitochondrial DNA contributes to the pathogenesis of systemic lupus erythematosis and IFN-related autoimmune diseases. Under steady-state conditions, pDCs play an important role in immune tolerance. In many types of human cancers, recruitment of pDCs to the tumor microenvironment contributes to the induction of immune tolerance. Here, we provide a systemic review of recent progress in studies on the role of pDCs in human diseases, including cancers and autoimmune/inflammatory diseases. PMID:29085361

Pathogenesis of NOD Diabetes is Initiated by Reactivity to the Insulin B Chain 9–23 Epitope and Involves Functional Epitope Spreading1

PubMed Central

Prasad, Suchitra; Kohm, Adam P.; McMahon, Jeffrey S.; Luo, Xunrong; Miller, Stephen D.

2012-01-01

Type 1 diabetes (T1D) is mediated by destruction of pancreatic β cells by CD4 and CD8 T cells specific for epitopes on numerous diabetogenic autoantigens resulting in loss of glucose homeostasis. Employing antigen-specific tolerance induced by i.v. administration of syngeneic splenocytes ECDI cross-linked to various diabetogenic antigens/epitopes (Ag-SP), we show that epitope spreading plays a functional role in the pathogenesis of T1D in NOD mice. Specifically, Ag-SP coupled with intact insulin, Ins B9–23 or Ins B15–23, but not GAD65509–528, GAD65524–543 or IGRP206–214, protected 4–6 week-old NOD mice from the eventual development of clinical disease; infiltration of immune cells to the pancreatic islets; and blocked the induction of DTH responses in a Treg-dependent, antigen-specific manner. However, tolerance induction in 19–21 week-old NOD mice was effectively accomplished only by Ins-SP, suggesting Ins B9–23 is a dominant initiating epitope, but autoimmune responses to insulin epitope(s) distinct from Ins B9–23 emerge during disease progression. PMID:22647732

Generating high temperature tolerant transgenic plants: Achievements and challenges.

PubMed

Grover, Anil; Mittal, Dheeraj; Negi, Manisha; Lavania, Dhruv

2013-05-01

Production of plants tolerant to high temperature stress is of immense significance in the light of global warming and climate change. Plant cells respond to high temperature stress by re-programming their genetic machinery for survival and reproduction. High temperature tolerance in transgenic plants has largely been achieved either by over-expressing heat shock protein genes or by altering levels of heat shock factors that regulate expression of heat shock and non-heat shock genes. Apart from heat shock factors, over-expression of other trans-acting factors like DREB2A, bZIP28 and WRKY proteins has proven useful in imparting high temperature tolerance. Besides these, elevating the genetic levels of proteins involved in osmotic adjustment, reactive oxygen species removal, saturation of membrane-associated lipids, photosynthetic reactions, production of polyamines and protein biosynthesis process have yielded positive results in equipping transgenic plants with high temperature tolerance. Cyclic nucleotide gated calcium channel proteins that regulate calcium influxes across the cell membrane have recently been shown to be the key players in induction of high temperature tolerance. The involvement of calmodulins and kinases in activation of heat shock factors has been implicated as an important event in governing high temperature tolerance. Unfilled gaps limiting the production of high temperature tolerant transgenic plants for field level cultivation are discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A pilot study of operational tolerance with a regulatory T-cell-based cell therapy in living donor liver transplantation.

PubMed

Todo, Satoru; Yamashita, Kenichiro; Goto, Ryoichi; Zaitsu, Masaaki; Nagatsu, Akihisa; Oura, Tetsu; Watanabe, Masaaki; Aoyagi, Takeshi; Suzuki, Tomomi; Shimamura, Tsuyoshi; Kamiyama, Toshiya; Sato, Norihiro; Sugita, Junichi; Hatanaka, Kanako; Bashuda, Hisashi; Habu, Sonoko; Demetris, Anthony J; Okumura, Ko

2016-08-01

Potent immunosuppressive drugs have significantly improved early patient survival after liver transplantation (LT). However, long-term results remain unsatisfactory because of adverse events that are largely associated with lifelong immunosuppression. To solve this problem, different strategies have been undertaken to induce operational tolerance, for example, maintenance of normal graft function and histology without immunosuppressive therapy, but have achieved limited success. In this pilot study, we aimed to induce tolerance using a novel regulatory T-cell-based cell therapy in living donor LT. Adoptive transfer of an ex vivo-generated regulatory T-cell-enriched cell product was conducted in 10 consecutive adult patients early post-LT. Cells were generated using a 2-week coculture of recipient lymphocytes with irradiated donor cells in the presence of anti-CD80/86 monoclonal antibodies. Immunosuppressive agents were tapered from 6 months, reduced every 3 months, and completely discontinued by 18 months. After the culture, the generated cells displayed cell-number-dependent donor-specific inhibition in the mixed lymphocyte reaction. Infusion of these cells caused no significant adverse events. Currently, all patients are well with normal graft function and histology. Seven patients have completed successful weaning and cessation of immunosuppressive agents. At present, they have been drug free for 16-33 months; 4 patients have been drug free for more than 24 months. The other 3 recipients with autoimmune liver diseases developed mild rejection during weaning and then resumed conventional low-dose immunotherapy. A cell therapy using an ex vivo-generated regulatory T-cell-enriched cell product is safe and effective for drug minimization and operational tolerance induction in living donor liver recipients with nonimmunological liver diseases. (Hepatology 2016;64:632-643). © 2016 by the American Association for the Study of Liver Diseases.

Sensitization of thermotolerant SCK cells to hyperthermia and freezing with reduction of intracellular pH: implications for cryosurgery.

PubMed

Burgher, Abram H; Swanlund, David J; Griffin, Robert J; Song, Chang W; Bischof, John C; Roberts, Kenneth P

2003-03-01

During cryosurgery, cells frozen slowly at the outer part of the ice ball undergo severe dehydration and are subject to solute effects injury, which may be caused in part by protein denaturation. This study was undertaken to determine whether heat shock proteins (HSPs), the molecular chaperones that stabilize proteins against denaturation, have a protective effect on cells during slow freezing. In addition, we aimed to determine whether acidic conditions, similar to those found in many solid tumors, would effect this protection. SCK cells were frozen at 5 degrees C/min to -10 degrees C or -20 degrees C before or after induction of thermotolerance, and at neutral or low pH conditions. Lethal damage was determined by clonogenics. Clonogenic survival was decreased by 50% in thermotolerant cells frozen to -10 degrees C after culture in acidic conditions (pH 6.6) compared with non-thermotolerant cells cultured at neutral pH. Induction of thermotolerance alone or low pH alone did not significantly sensitize SCK cells to freezing. All treatment groups were equally susceptible to killing when frozen to -20 degrees C. Our results show that induction of thermal tolerance does not protect SCK cells against subsequent freezing injury and that a low pH environment actually sensitizes these cells to freeze injury. Copyright 2003 Wiley-Liss, Inc.

Immunomodulation of Experimental Autoimmune Encephalomyelitis by Oral Administration of Copolymer 1

NASA Astrophysics Data System (ADS)

Teitelbaum, Dvora; Arnon, Ruth; Sela, Michael

1999-03-01

The activity of copolymer 1 (Cop 1, Copax-one, glatiramer acetate) in suppressing experimental autoimmune encephalomyelitis (EAE) and in the treatment of multiple sclerosis patients when injected parenterally has been extensively demonstrated. In the present study we addressed the question of whether Cop 1 can induce oral tolerance to EAE similar to myelin basic protein (MBP). We now have demonstrated that oral Cop 1 inhibited EAE induction in both rats and mice. Furthermore, oral Cop 1 was more effective than oral MBP in suppressing EAE in rats. The beneficial effect of oral Cop 1 was found to be associated with specific inhibition of the proliferative and Th1 cytokine secretion responses to MBP of spleen cells from Cop 1-fed mice and rats. In all of these assays, oral Cop 1 was more effective than oral MBP. The tolerance induced by Cop 1 could be adoptively transferred with spleen cells from Cop 1-fed animals. Furthermore, Cop 1-specific T cell lines, which inhibit EAE induction in vivo, could be isolated from the above spleen cells. These T cell lines secrete the anti-inflammatory cytokines IL-10 and transforming growth factor type β , but not IL-4, in response to both Cop 1 and MBP. In conclusion, oral Cop 1 has a beneficial effect on the development of EAE that is associated with down-regulation of T cell immune responses to MBP and is mediated by Th2/3 type regulatory cells. These results suggest that oral administration of Cop 1 may modulate multiple sclerosis as well.

Nuclear calcium is required for human T cell activation

PubMed Central

Samstag, Yvonne

2016-01-01

Calcium signals in stimulated T cells are generally considered single entities that merely trigger immune responses, whereas costimulatory events specify the type of reaction. Here we show that the “T cell calcium signal” is a composite signal harboring two distinct components that antagonistically control genomic programs underlying the immune response. Using human T cells from healthy individuals, we establish nuclear calcium as a key signal in human T cell adaptogenomics that drives T cell activation and is required for signaling to cyclic adenosine monophosphate response element–binding protein and the induction of CD25, CD69, interleukin-2, and γ-interferon. In the absence of nuclear calcium signaling, cytosolic calcium activating nuclear factor of activated T cells translocation directed the genomic response toward enhanced expression of genes that negatively modulate T cell activation and are associated with a hyporesponsive state. Thus, nuclear calcium controls the T cell fate decision between a proliferative immune response and tolerance. Modulators of nuclear calcium–driven transcription may be used to develop a new type of pro-tolerance immunosuppressive therapy. PMID:27810914

Induction of hapten-specific tolerance of human CD8+ urushiol (poison ivy)-reactive T lymphocytes.

PubMed

Kalish, R S; Wood, J A

1997-03-01

The interaction of CD28 with B7 molecules (CD80 or CD86) is an essential second signal for both the activation of CD4+ T cells through the T-cell receptor and the prevention of anergy. We studied the requirement of hapten-specific human CD8+ cells for CD28 co-stimulation in recognition of hapten, and anergy induction. Urushiol, the immunogenic hapten of poison ivy (Toxicodendron radicans), elicits a predominantly CD8+ T-cell response. Autologous PBMC were pre-incubated with urushiol prior to fixation by paraformaldehyde. Fixed antigen-presenting cells were unable to present urushiol to human CD8+ urushiol-specific T cells. Addition of anti-CD28, however, overcame this antigen-presenting defect, enabling CD8+ cells to proliferate. Fixation of antigen-presenting cells prevents upregulation of B7, and addition of anti-CD28 substitutes for this signal. Proliferation of CD8+ T cells in response to urushiol was blocked by CTLA4Ig, a recombinant fusion protein that blocks CD28/B7 interactions. Preincubation of urushiol-specific CD8+ cells with fixed PBMC + urushiol for 7 d induced anergy. Anergic CD8+ cells were viable and able to proliferate in response to IL-2, but not in response to urushiol. Induction of anergy required the presence of urushiol, and pre-incubation with irradiated PBMC + urushiol did not have this effect. It is proposed that anergy was induced by presentation of urushiol by fixed PBMC, in the absence of adequate co-stimulation signals. Induction of anergy by blocking of co-stimulation could potentially induce clinical hyposensitization to haptens.

Recent Progress in Cell Therapy in Solid Organ Transplantation

PubMed Central

Garakani, R.; Saidi, R. F.

2017-01-01

There has been ample of preclinical and animal studies showing efficacy and safety of using various cells, such as stem cells or T regulatory cells, after transplantation for tissue repair, immunosuppression or tolerance induction. However, there has been a significant progress recently using cell therapy in solid organ transplantation in small clinical trials. Recent results have been promising and using cell therapy in solid organ transplantation seems feasible and safe. However, there are more hurdles to overcome such as dose and timing of the infusions. Current studies mainly focused on live donor kidney transplantation. Expansion of current regimes to other organs and deceased donor transplantation would be crucial. PMID:28924460

Early cytokine modulation after the rapid induction phase of sublingual immunotherapy with mite monomeric allergoids.

PubMed

Di Gioacchino, M; Perrone, A; Petrarca, C; Di Claudio, F; Mistrello, G; Falagiani, P; Dadorante, V; Verna, N; Braga, M; Ballone, E; Cavallucci, E

2008-01-01

The influence of different treatment schedules of sublingual immunotherapy (SLIT) in activating IL-10-producing T-cells, crucial in inducing allergen-specific tolerance, is not completely understood. The present work was designed to evaluate allergen driven interleukin release by mononuclear cells in the early phase of SLIT, after application of different induction schemes. Twenty mite-allergic patients were enrolled, 10 (group A) treated with a traditional 98 day induction scheme and 10 (group B) with a 16 day scheme with monomeric allergoid vaccine. At the end of the induction phase, the cumulative doses taken by group A and group B patients were equivalent to 50.5 and 50.3 microg of mite group 1 allergens, respectively. The release of Th1-, Th2- and Treg-related interleukins was assessed in culture supernatants of 5 microg/ml Der-p1-stimulated mononuclear cells, isolated before and after the induction phases. No relevant treatment-related side effects were observed. Interleukin release was similar in the two groups at the enrolment. Non-stimulated and Der p 1 stimulated release of studied cytokines was similar in the two groups at enrolment. Der p 1 stimulation significantly increased IL-10 release (p<0.0002) after treatment in group B patients, and this effect was higher (p=0.05) compared to group A patients. Furthermore, at the end of SLIT induction TNF-alpha, IL-4 and IFN-gamma production were reduced in group B patients (p<0.05, p=0.062 and p=0.060, respectively). The rapid induction scheme of sublingual immunotherapy induces an early immune suppression more effectively than the slower one. The rapid induction scheme should be the preferential way to start sublingual immunotherapy, particularly when monomeric allergoids are utilized.

An improved fault-tolerant control scheme for PWM inverter-fed induction motor-based EVs.

PubMed

Tabbache, Bekheïra; Benbouzid, Mohamed; Kheloui, Abdelaziz; Bourgeot, Jean-Matthieu; Mamoune, Abdeslam

2013-11-01

This paper proposes an improved fault-tolerant control scheme for PWM inverter-fed induction motor-based electric vehicles. The proposed strategy deals with power switch (IGBTs) failures mitigation within a reconfigurable induction motor control. To increase the vehicle powertrain reliability regarding IGBT open-circuit failures, 4-wire and 4-leg PWM inverter topologies are investigated and their performances discussed in a vehicle context. The proposed fault-tolerant topologies require only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, mitigating the IGBTs failures by specific inverter control. Indeed, the two topologies exploit the induction motor neutral accessibility for fault-tolerant purposes. The 4-wire topology uses then classical hysteresis controllers to account for the IGBT failures. The 4-leg topology, meanwhile, uses a specific 3D space vector PWM to handle vehicle requirements in terms of size (DC bus capacitors) and cost (IGBTs number). Experiments on an induction motor drive and simulations on an electric vehicle are carried-out using a European urban driving cycle to show that the proposed fault-tolerant control approach is effective and provides a simple configuration with high performance in terms of speed and torque responses. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Heat Tolerance Induction of the Indian Meal Moth (Lepidoptera: Pyralidae) Is Accompanied by Upregulation of Heat Shock Proteins and Polyols.

PubMed

Kim, Minhyun; Lee, Seunghee; Chun, Yong Shik; Na, Jahyun; Kwon, Hyeok; Kim, Wook; Kim, Yonggyun

2017-08-01

The Indian meal moth, Plodia interpunctella, causes massive damage to stored grains and processed foods. Heat treatment has been widely used to control insect pests infesting stored grains. However, heat treatment may result in unsatisfactory control owing to heat tolerance of target insects. This study quantified the heat tolerance and analyzed its induction in P. interpunctella. Susceptibility of P. interpunctella to different high temperatures was assessed in all developmental stages. Heat treatment at 44 °C for 1 h caused significant mortalities to all developmental stages, with late-instar larvae exhibiting the highest tolerance. However, the survivorship to heat treatment was significantly increased by pre-exposure to 37 °C for 30 min. The induction of heat tolerance was accompanied by upregulation of two heat shock proteins of Hsc70 and Hsp90. Trehalose and glycerol concentrations in the hemolymph also increased after pre-exposure to 37 °C for 30 min. RNA interference (RNAi) by specific double-stranded RNAs effectively suppressed the inducible expressions of both Hsc70 and Hsp90 in response to 37 °C for 30 min. Either RNAi of Hsc70 or Hsp90 significantly impaired the heat tolerance induction of P. interpunctella. These results suggest that the induction of heat tolerance in P. interpunctella involves the upregulation of these heat shock proteins and hemolymph polyol levels. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RORC2 is involved in T cell polarization through interaction with the FOXP3 promoter.

PubMed

Burgler, Simone; Mantel, Pierre-Yves; Bassin, Claudio; Ouaked, Nadia; Akdis, Cezmi A; Schmidt-Weber, Carsten B

2010-06-01

The process of Th cell differentiation toward polarized effector T cells tailors specific immunity against invading pathogens while allowing tolerance against commensal microorganisms, harmless allergens, or autologous Ags. Identification of the mechanisms underlying this polarization process is therefore central to understand how the immune system confers immunity and tolerance. The present study demonstrates that retinoic acid receptor-related orphan receptor C2 (RORC2), a key transcription factor in Th17 cell development, inhibits FOXP3 expression in human T cells. Although overexpression of RORC2 in naive T cells reduces levels of FOXP3, small interfering RNA-mediated knockdown of RORC2 enhances its expression. RORC2 mediates this inhibition at least partially by binding to two out of four ROR-responsive elements on the FOXP3 promoter. Knockdown of RORC2 promotes high FOXP3 levels and decreased expression of proinflammatory cytokines beta form of pro-IL-1, IL-6, IL-17A, IFN-gamma, and TNF-alpha in differentiating naive T cells, suggesting that the role of RORC2 in Th17 cell development involves not only induction of Th17-characteristic genes, but also suppression of regulatory T cell-specific programs. Together, this study identifies RORC2 as a polarizing factor in transcriptional cross-regulation and provides novel viewpoints on the control of immune tolerance versus effector immune responses.

Local Tacrolimus (FK506) Delivery for Prevention of Acute Rejection in the Nonhuman Primate Delayed Mixed Chimerism Vascularized Composite Allograft Tolerance Induction Protocol

DTIC Science & Technology

2016-10-01

Chimerism Vascularized Composite Allograft Tolerance Induction Protocol PRINCIPAL INVESTIGATORS: Dr. Curtis L. Cetrulo CONTRACTING ORGANIZATION...Tacrolimus (FK506) Delivery for Prevention of Acute Rejection in the Nonhuman Primate Delayed Mixed Chimerism Vascularized Composite Allograft Tolerance...tacrolimus, FK506, vascularized composite allografts , immune rejection, preclinical, transplant, nonhuman primate model, degradable polymer, tyrosine

Vagotomy Affects the Development of Oral Tolerance and Increases Susceptibility to Develop Colitis Independently of α-7 Nicotinic Receptor

PubMed Central

Di Giovangiulio, Martina; Bosmans, Goele; Meroni, Elisa; Stakenborg, Nathalie; Florens, Morgane; Farro, Giovanna; Gomez-Pinilla, Pedro J; Matteoli, Gianluca; Boeckxstaens, Guy E

2016-01-01

Vagotomy (VGX) increases the susceptibility to develop colitis suggesting a crucial role for the cholinergic anti-inflammatory pathway in the regulation of the immune responses. Since oral tolerance and the generation of regulatory T cells (Tregs) are crucial to preserve mucosal immune homeostasis, we studied the effect of vagotomy and the involvement of α7 nicotinic receptors (α7nAChR) at the steady state and during colitis. Therefore, the development of both oral tolerance and colitis (induced by dextran sulfate sodium (DSS) or via T cell transfer) was studied in vagotomized mice and in α7nAChR-/- mice. VGX, but not α7nAChR deficiency, prevented oral tolerance establishment. This effect was associated with reduced Treg conversion in the lamina propria and mesenteric lymphnodes. To the same extent, vagotomized mice, but not α7nAChR-/- mice, developed a more severe DSS colitis compared with control mice treated with DSS, associated with a decreased number of colonic Tregs. However, neither VGX nor absence of α7nAChR in recipient mice affected colitis development in the T cell transfer model. In line, deficiency of α7nAChR exclusively in T cells did not influence the development of colitis induced by T cell transfer. Our results indicate a key role for the vagal intestinal innervation in the development of oral tolerance and colitis, most likely by modulating induction of Tregs independently of α7nAChR. PMID:27341335

Collaborating with the enemy: function of macrophages in the development of neoplastic disease.

PubMed

Eljaszewicz, Andrzej; Wiese, Małgorzata; Helmin-Basa, Anna; Jankowski, Michal; Gackowska, Lidia; Kubiszewska, Izabela; Kaszewski, Wojciech; Michalkiewicz, Jacek; Zegarski, Wojciech

2013-01-01

Due to the profile of released mediators (such as cytokines, chemokines, growth factors, etc.), neoplastic cells modulate the activity of immune system, directly affecting its components both locally and peripherally. This is reflected by the limited antineoplastic activity of the immune system (immunosuppressive effect), induction of tolerance to neoplastic antigens, and the promotion of processes associated with the proliferation of neoplastic tissue. Most of these responses are macrophages dependent, since these cells show proangiogenic properties, attenuate the adaptive response (anergization of naïve T lymphocytes, induction of Treg cell formation, polarization of immune response towards Th2, etc.), and support invasion and metastases formation. Tumor-associated macrophages (TAMs), a predominant component of leukocytic infiltrate, "cooperate" with the neoplastic tissue, leading to the intensified proliferation and the immune escape of the latter. This paper characterizes the function of macrophages in the development of neoplastic disease.

Overexpression of the DNA mismatch repair factor, PMS2, confers hypermutability and DNA damage tolerance.

PubMed

Gibson, Shannon L; Narayanan, Latha; Hegan, Denise Campisi; Buermeyer, Andrew B; Liskay, R Michael; Glazer, Peter M

2006-12-08

Inherited defects in genes associated with DNA mismatch repair (MMR) have been linked to familial colorectal cancer. Cells deficient in MMR are genetically unstable and demonstrate a tolerance phenotype in response to certain classes of DNA damage. Some sporadic human cancers also show abnormalities in MMR gene function, typically due to diminished expression of one of the MutL homologs, MLH1. Here, we report that overexpression of the MutL homolog, human PMS2, can also cause a disruption of the MMR pathway in mammalian cells, resulting in hypermutability and DNA damage tolerance. A mouse fibroblast cell line carrying a recoverable lambda phage shuttle vector for mutation detection was transfected with either a vector designed to express hPMS2 or with an empty vector control. Cells overexpressing hPMS2 were found to have elevated spontaneous mutation frequencies at the cII reporter gene locus. They also showed an increase in the level of mutations induced by the alkylating agent, methynitrosourea (MNU). Clonogenic survival assays demonstrated increased survival of the PMS2-overexpressing cells following exposure to MNU, consistent with the induction of a damage tolerance phenotype. Similar results were seen in cells expressing a mutant PMS2 gene, containing a premature stop codon at position 134 and representing a variant found in an individual with familial colon cancer. These results show that dysregulation of PMS2 gene expression can disrupt MMR function in mammalian cells and establish an additional carcinogenic mechanism by which cells can develop genetic instability and acquire resistance to cytotoxic cancer therapies.

The Potential Role of an Endotoxin Tolerance-Like Mechanism for the Anti-Inflammatory Effect of Spirulina platensis Organic Extract in Macrophages.

PubMed

Pham, Tho X; Park, Young-Ki; Bae, Minkyung; Lee, Ji-Young

2017-03-01

Endotoxin tolerance is a phenomenon where exposure of innate immune cells to lipopolysaccharide (LPS) induces a refractory state to subsequent endotoxin exposures. The goal of this study was to investigate if Spirulina platensis organic extract (SPE) induces an endotoxin tolerance-like state. We used splenocytes and peritoneal macrophages from C57BL/6J mice fed a high-fat/high-sucrose (HF/HS) control or a HF/HS diet containing 0.25% (w/w) SPE for 16 weeks for ex vivo LPS stimulation and endotoxin-tolerant (ET) macrophages to evaluate the effects of SPE on endotoxin tolerance. Cells from SPE-fed mice displayed significantly less expression of proinflammatory genes than those from control mice. ET macrophages were produced in vitro by incubating RAW 264.7 macrophages with low-dose LPS to determine the energy phenotype of naive, SPE-treated, and ET macrophages. Compared to naive macrophages exposed to a high-dose LPS (100 ng/mL) for the first time, ET macrophages showed significantly less proinflammatory gene expression after LPS stimulation, which was also observed with SPE treatment. Consistently, nuclear translocation of p65 was markedly reduced in both ET- and SPE-treated macrophages on LPS stimulation with increase in nuclear protein levels of p50 and B cell lymphoma 3-encoded protein. In conclusion, the anti-inflammatory effect of SPE is at least partly attributable to the induction of an endotoxin tolerance-like state in macrophages, which shares common characteristics of macrophage endotoxin tolerance.

Systemic IL-2/anti-IL-2Ab complex combined with sublingual immunotherapy suppresses experimental food allergy in mice through induction of mucosal regulatory T cells.

PubMed

Smaldini, P L; Trejo, F; Cohen, J L; Piaggio, E; Docena, G H

2018-04-01

Therapeutic tolerance restoration has been proven to modify food allergy in patients and animal models and although sublingual immunotherapy (SLIT) has showed promise, combined therapy may be necessary to achieve a strong and long-term tolerance. In this work, we combined SLIT with systemic administration of IL-2 associated with an anti-IL-2 monoclonal antibody (IL-2/anti-IL-2Ab complex or IL-2C) to reverse the IgE-mediated experimental allergy. Balb/c mice were sensitized with cholera toxin and milk proteins and orally challenged with allergen to elicit hypersensitivity reactions. Then, allergic mice were treated with a sublingual administration of very low amounts of milk proteins combined with intraperitoneal injection of low doses of IL-2C. The animals were next re-exposed to allergens and mucosal as well as systemic immunological parameters were assessed in vivo and in vitro. The treatment reduced serum specific IgE, IL-5 secretion by spleen cells and increased IL-10 and TGF-β in the lamina propria of buccal and duodenal mucosa. We found an augmented frequency of IL-10-secreting CD4 + CD25 + Foxp3 + regulatory T cells (Treg) in the submaxilar lymph nodes and buccal lamina propria. Tregs were sorted, characterized and adoptively transferred to naïve mice, which were subsequently sensitized. No allergy was experienced in these mice and we encouragingly discovered a faster and more efficient tolerance induction with the combined therapy compared with SLIT. The combination of two therapeutic strategies rendered Treg-mediated tolerance more efficient compared to individual treatments and reversed the established IgE-mediated food allergy. This approach highlights the ability of IL-2C to expand Tregs, and it may represent a promising disease-modifying therapy for managing food allergy. © 2018 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Tolerance response of multidrug-resistant Salmonella enterica strains to habituation to Origanum vulgare L. essential oil

PubMed Central

Monte, Daniel F. M.; Tavares, Adassa G.; Albuquerque, Allan R.; Sampaio, Fábio C.; Oliveira, Tereza C. R. M.; Franco, Octavio L.; Souza, Evandro L.; Magnani, Marciane

2014-01-01

Multidrug-resistant Salmonella enterica isolates from human outbreaks or from poultry origin were investigated for their ability to develop direct-tolerance or cross-tolerance to sodium chloride, potassium chloride, lactic acid, acetic acid, and ciprofloxacin after habituation in subinhibitory amounts ( of the minimum inhibitory concentration – (MIC) and of the minimum inhibitory concentration – MIC) of Origanum vulgare L. essential oil (OVEO) at different time intervals. The habituation of S. enterica to OVEO did not induce direct-tolerance or cross-tolerance in the tested strains, as assessed by the modulation of MIC values. However, cells habituated to OVEO maintained or increased susceptibility to the tested antimicrobials agents, with up to fourfold double dilution decrease from previously determined MIC values. This study reports for the first time the non-inductive effect of OVEO on the acquisition of direct-tolerance or cross-tolerance in multidrug-resistant S. enterica strains to antimicrobial agents that are largely used in food preservation, as well as to CIP, the therapeutic drug of salmonellosis. PMID:25566231

Heme Oxygenase-1 Induction and Organic Nitrate Therapy: Beneficial Effects on Endothelial Dysfunction, Nitrate Tolerance, and Vascular Oxidative Stress

PubMed Central

Daiber, Andreas; Oelze, Matthias; Wenzel, Philip; Bollmann, Franziska; Pautz, Andrea; Kleinert, Hartmut

2012-01-01

Organic nitrates are a group of very effective anti-ischemic drugs. They are used for the treatment of patients with stable angina, acute myocardial infarction, and chronic congestive heart failure. A major therapeutic limitation inherent to organic nitrates is the development of tolerance, which occurs during chronic treatment with these agents, and this phenomenon is largely based on induction of oxidative stress with subsequent endothelial dysfunction. We therefore speculated that induction of heme oxygenase-1 (HO-1) could be an efficient strategy to overcome nitrate tolerance and the associated side effects. Indeed, we found that hemin cotreatment prevented the development of nitrate tolerance and vascular oxidative stress in response to chronic nitroglycerin therapy. Vice versa, pentaerithrityl tetranitrate (PETN), a nitrate that was previously reported to be devoid of adverse side effects, displayed tolerance and oxidative stress when the HO-1 pathway was blocked pharmacologically or genetically by using HO-1+/– mice. Recently, we identified activation of Nrf2 and HuR as a principle mechanism of HO-1 induction by PETN. With the present paper, we present and discuss our recent and previous findings on the role of HO-1 for the prevention of nitroglycerin-induced nitrate tolerance and for the beneficial effects of PETN therapy. PMID:22506100

Macrophages play an essential role in antigen-specific immune suppression mediated by T CD8⁺ cell-derived exosomes.

PubMed

Nazimek, Katarzyna; Ptak, Wlodzimierz; Nowak, Bernadeta; Ptak, Maria; Askenase, Philip W; Bryniarski, Krzysztof

2015-09-01

Murine contact sensitivity (CS) reaction could be antigen-specifically regulated by T CD8(+) suppressor (Ts) lymphocytes releasing microRNA-150 in antibody light-chain-coated exosomes that were formerly suggested to suppress CS through action on macrophages (Mφ). The present studies investigated the role of Mφ in Ts cell-exosome-mediated antigen-specific suppression as well as modulation of Mφ antigen-presenting function in humoral and cellular immunity by suppressive exosomes. Mice depleted of Mφ by clodronate liposomes could not be tolerized and did not produce suppressive exosomes. Moreover, isolated T effector lymphocytes transferring CS were suppressed by exosomes only in the presence of Mφ, demonstrating the substantial role of Mφ in the generation and action of Ts cell regulatory exosomes. Further, significant decrease of number of splenic B cells producing trinitrophenyl (TNP) -specific antibodies with the alteration of the ratio of serum titres of IgM to IgG was observed in recipients of exosome-treated, antigen-pulsed Mφ and the significant suppression of CS was demonstrated in recipients of exosome-treated, TNP-conjugated Mφ. Additionally, exosome-pulsed, TNP-conjugated Mφ mediated suppression of CS in mice pre-treated with a low-dose of cyclophosphamide, suggesting de novo induction of T regulatory (Treg) lymphocytes. Treg cell involvement in the effector phase of the studied suppression mechanism was proved by unsuccessful tolerization of DEREG mice depleted of Treg lymphocytes. Furthermore, the inhibition of proliferation of CS effector cells cultured with exosome-treated Mφ in a transmembrane manner was observed. Our results demonstrated the essential role of Mφ in antigen-specific immune suppression mediated by Ts cell-derived exosomes and realized by induction of Treg lymphocytes and inhibition of T effector cell proliferation. © 2015 John Wiley & Sons Ltd.

MyD88-dependent pro-interleukin-1β induction in dendritic cells exposed to food-grade synthetic amorphous silica.

PubMed

Winkler, Hans Christian; Kornprobst, Julian; Wick, Peter; von Moos, Lea Maria; Trantakis, Ioannis; Schraner, Elisabeth Maria; Bathke, Barbara; Hochrein, Hubertus; Suter, Mark; Naegeli, Hanspeter

2017-06-23

Dendritic cells (DCs) are specialized first-line sensors of foreign materials invading the organism. These sentinel cells rely on pattern recognition receptors such as Nod-like or Toll-like receptors (TLRs) to launch immune reactions against pathogens, but also to mediate tolerance to self-antigens and, in the intestinal milieu, to nutrients and commensals. Since inappropriate DC activation contributes to inflammatory diseases and immunopathologies, a key question in the evaluation of orally ingested nanomaterials is whether their contact with DCs in the intestinal mucosa disrupts this delicate homeostatic balance between pathogen defense and tolerance. Here, we generated steady-state DCs by incubating hematopoietic progenitors with feline McDonough sarcoma-like tyrosine kinase 3 ligand (Flt3L) and used the resulting immature DCs to test potential biological responses against food-grade synthetic amorphous silica (SAS) representing a common nanomaterial generally thought to be safe. Interaction of immature and unprimed DCs with food-grade SAS particles and their internalization by endocytic uptake fails to elicit cytotoxicity and the release of interleukin (IL)-1α or tumor necrosis factor-α, which were identified as master regulators of acute inflammation in lung-related studies. However, the display of maturation markers on the cell surface shows that SAS particles activate completely immature DCs. Also, the endocytic uptake of SAS particles into these steady-state DCs leads to induction of the pro-IL-1β precursor, subsequently cleaved by the inflammasome to secrete mature IL-1β. In contrast, neither pro-IL-1β induction nor mature IL-1β secretion occurs upon internalization of TiO 2 or FePO 4 nanoparticles. The pro-IL-1β induction is suppressed by pharmacologic inhibitors of endosomal TLR activation or by genetic ablation of MyD88, a downstream adapter of TLR pathways, indicating that endosomal pattern recognition is responsible for the observed cytokine response to food-grade SAS particles. Our results unexpectedly show that food-grade SAS particles are able to directly initiate the endosomal MyD88-dependent pathogen pattern recognition and signaling pathway in steady-state DCs. The ensuing activation of immature DCs with de novo induction of pro-IL-1β implies that the currently massive use of SAS particles as food additive should be reconsidered.

Foreignness as a matter of degree: the relative immunogenicity of peptide/MHC ligands.

PubMed

van den Berg, Hugo A; Rand, David A

2004-12-21

The ability of T lymphocytes (T cells) to recognize and attack foreign invaders while leaving healthy cells unharmed is often analysed as a discrete self/non-self dichotomy, with each peptide/MHC ligand classified as either self or non-self. We argue that the ligand immunogenicity is more naturally treated as a continuous quantity, and show how to define and quantitate relative ligand immunogenicity. In our theory, self-tolerance is acquired through reduction of the relative immunogenicity of autoantigens, whereas xenoantigens, typically not presented during induction of deletional tolerance, retain a high degree of relative immunogenicity. Autoantigens that are not prominently presented in deletional tolerance likewise retain a high relative immunogenicity and remain essentially foreign. According to our analysis, any given autoantigen can attain a high level of relative immunogenicity, provided it is presented at sufficiently high levels. Our theory provides a quantitative tool to analyse the immunogenicity of tumour-associated neoantigens and the aetiology of autoimmune disease.

Is basiliximab induction, a novel risk factor for new onset diabetes after transplantation for living donor renal allograft recipients?

PubMed

Prasad, Narayan; Gurjer, Desraj; Bhadauria, Dharmender; Gupta, Amit; Srivastava, Aneesh; Kaul, Anupama; Jaiswal, Akhilesh; Yadav, Brijesh; Yadav, Subhash; Sharma, Raj K

2014-04-01

It was found that, by affecting populations of T lymphocytes and regulatory T cells, basiliximab also indirectly affects pancreatic β-cell function and glucose homeostasis. In this prospective observational study, we included all renal transplant recipients from 1 July 2007 to 31 July 2011. The overall incidence of hyperglycaemia (transient hyperglycaemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and new onset diabetes after transplantation (NODAT)) was compared between patients with and without basiliximab induction. Of the 439 eligible study patients, 105 patients received basiliximab induction and 334 patients did not. Overall hyperglycaemia (transient hyperglycaemia, IFG, IGT and NODAT) was detected in 102/334 (30.5%) patients without induction and 44/105 (41.9%) patients with induction (P = 0.03). Of the 102 patients with hyperglycaemia in patients without basiliximab, 46 (45.1%) patients improved, while only 10 (22.7%) of the 44 patients with basiliximab improved (P = 0.016) at the end of 3 months. Finally, NODAT was observed in 56/334 (16.7%) patients without induction and 102/334 (30.5%) patients with induction. Relative risk of NODAT with basiliximab was 2.3 (95% CI 1.4-3.9) compared to that of patients without induction. Basiliximab and hepatitis C virus infection were independent risk factors for NODAT. Risk of NODAT remained high with basiliximab despite adjusting the acute rejections episodes. Basiliximab induction prevents acute rejection; however, it is associated with increased risk of NODAT. © 2014 Asian Pacific Society of Nephrology.

Innate Immunity and Resistance to Tolerogenesis in Allotransplantation

PubMed Central

Benichou, Gilles; Tonsho, Makoto; Tocco, Georges; Nadazdin, Ognjenka; Madsen, Joren C.

2012-01-01

The development of immunosuppressive drugs to control adaptive immune responses has led to the success of transplantation as a therapy for end-stage organ failure. However, these agents are largely ineffective in suppressing components of the innate immune system. This distinction has gained in clinical significance as mounting evidence now indicates that innate immune responses play important roles in the acute and chronic rejection of whole organ allografts. For instance, whereas clinical interest in natural killer (NK) cells was once largely confined to the field of bone marrow transplantation, recent findings suggest that these cells can also participate in the acute rejection of cardiac allografts and prevent tolerance induction. Stimulation of Toll-like receptors (TLRs), another important component of innate immunity, by endogenous ligands released in response to ischemia/reperfusion is now known to cause an inflammatory milieu favorable to graft rejection and abrogation of tolerance. Emerging data suggest that activation of complement is linked to acute rejection and interferes with tolerance. In summary, the conventional wisdom that the innate immune system is of little importance in whole organ transplantation is no longer tenable. The addition of strategies that target TLRs, NK cells, complement, and other components of the innate immune system will be necessary to eventually achieve long-term tolerance to human allograft recipients. PMID:22566954

A simple and powerful approach for isolation of Arabidopsis mutants with increased tolerance to H2O2-induced cell death.

PubMed

Gechev, Tsanko; Mehterov, Nikolay; Denev, Iliya; Hille, Jacques

2013-01-01

A genetic approach is described to isolate mutants more tolerant to oxidative stress. A collection of T-DNA activation tag Arabidopsis thaliana mutant lines was screened for survivors under conditions that trigger H2O2-induced cell death. Oxidative stress was induced by applying the catalase (CAT) inhibitor aminotriazole (AT) in the growth media, which results in decrease in CAT enzyme activity, H2O2 accumulation, and subsequent plant death. One mutant was recovered from the screening and named oxr1 (oxidative stress resistant 1). The location of the T-DNA insertion was identified by TAIL-PCR. Oxr1 exhibited lack of cell death symptoms and more fresh weight and chlorophyll content compared to wild type. The lack of cell death correlated with more prominent induction of anthocyanins synthesis in oxr1. These results demonstrate the feasibility of AT as a screening agent for the isolation of oxidative stress-tolerant mutants and indicate a possible protective role for anthocyanins against AT-induced cell death. The chapter includes protocols for ethyl methanesulfonate mutagenesis, mutant screening using AT, T-DNA identification by TAIL-PCR, CAT activity measurements, and determination of malondialdehyde, chlorophyll, and anthocyanins. Copyright © 2013 Elsevier Inc. All rights reserved.

Xenografted human amniotic membrane-derived mesenchymal stem cells are immunologically tolerated and transdifferentiated into cardiomyocytes.

PubMed

Tsuji, Hiroko; Miyoshi, Shunichiro; Ikegami, Yukinori; Hida, Naoko; Asada, Hironori; Togashi, Ikuko; Suzuki, Junshi; Satake, Masaki; Nakamizo, Hikaru; Tanaka, Mamoru; Mori, Taisuke; Segawa, Kaoru; Nishiyama, Nobuhiro; Inoue, Junko; Makino, Hatsune; Miyado, Kenji; Ogawa, Satoshi; Yoshimura, Yasunori; Umezawa, Akihiro

2010-05-28

Amniotic membrane is known to have the ability to transdifferentiate into multiple organs and is expected to stimulate a reduced immunologic reaction. Determine whether human amniotic membrane-derived mesenchymal cells (hAMCs) can be an ideal allograftable stem cell source for cardiac regenerative medicine. We established hAMCs. After cardiomyogenic induction in vitro, hAMCs beat spontaneously, and the calculated cardiomyogenic transdifferentiation efficiency was 33%. Transplantation of hAMCs 2 weeks after myocardial infarction improved impaired left ventricular fractional shortening measured by echocardiogram (34+/-2% [n=8] to 39+/-2% [n=11]; P<0.05) and decreased myocardial fibrosis area (18+/-1% [n=9] to 13+/-1% [n=10]; P<0.05), significantly. Furthermore hAMCs transplanted into the infarcted myocardium of Wistar rats were transdifferentiated into cardiomyocytes in situ and survived for more than 4 weeks after the transplantation without using any immunosuppressant. Immunologic tolerance was caused by the hAMC-derived HLA-G expression, lack of MHC expression of hAMCs, and activation of FOXP3-positive regulatory T cells. Administration of IL-10 or progesterone, which is known to play an important role in feto-maternal tolerance during pregnancy, markedly increased HLA-G expression in hAMCs in vitro and, surprisingly, also increased cardiomyogenic transdifferentiation efficiency in vitro and in vivo. Because hAMCs have a high ability to transdifferentiate into cardiomyocytes and to acquire immunologic tolerance in vivo, they can be a promising cellular source for allograftable stem cells for cardiac regenerative medicine.

Thymus medulla under construction: Time and space oddities.

PubMed

Alves, Nuno L; Ribeiro, Ana R

2016-04-01

The development of effective T-cell-based immunotherapies to treat infection, cancer, and autoimmunity should incorporate the ground rules that control differentiation of T cells in the thymus. Within the thymus, thymic epithelial cells (TECs) provide microenvironments supportive of the generation and selection of T cells that are responsive to pathogen-derived antigens, and yet tolerant to self-determinants. Defects in TEC differentiation cause syndromes that range from immunodeficiency to autoimmunity, which makes the study of TECs of fundamental and clinical importance to comprehend how immunity and tolerance are balanced. Critical to tolerance induction are medullary thymic epithelial cells (mTECs), which purge autoreactive T cells, or redirect them to a regulatory T-cell lineage. In this issue of the European Journal of Immunology, studies by Baik et al. and Mayer et al. [Eur. J. Immunol. 2016. 46: XXXX-XXXX and 46: XXXX-XXXX]) document novel spatial-temporal singularities in the lineage specification and maintenance of mTECs. While Baik et al. define a developmental checkpoint during mTEC specification in the embryo, Mayer et al. reveal that the generation and maintenance of the adult mTEC compartment is temporally controlled in vivo. The two reports described new developmentally related, but temporally distinct principles that underlie the homeostasis of the thymic medulla across life. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Upregulated Transcription of Plasmid and Chromosomal Ribulose Monophosphate Pathway Genes Is Critical for Methanol Assimilation Rate and Methanol Tolerance in the Methylotrophic Bacterium Bacillus methanolicus

PubMed Central

Jakobsen, Øyvind M.; Benichou, Aline; Flickinger, Michael C.; Valla, Svein; Ellingsen, Trond E.; Brautaset, Trygve

2006-01-01

The natural plasmid pBM19 carries the key mdh gene needed for the oxidation of methanol into formaldehyde by Bacillus methanolicus. Five more genes, glpX, fba, tkt, pfk, and rpe, with deduced roles in the cell primary metabolism, are also located on this plasmid. By using real-time PCR, we show that they are transcriptionally upregulated (6- to 40-fold) in cells utilizing methanol; a similar induction was shown for two chromosomal genes, hps and phi. These seven genes are involved in the fructose bisphosphate aldolase/sedoheptulose bisphosphatase variant of the ribulose monophosphate (RuMP) pathway for formaldehyde assimilation. Curing of pBM19 causes higher methanol tolerance and reduced formaldehyde tolerance, and the methanol tolerance is reversed to wild-type levels by reintroducing mdh. Thus, the RuMP pathway is needed to detoxify the formaldehyde produced by the methanol dehydrogenase-mediated conversion of methanol, and the in vivo transcription levels of mdh and the RuMP pathway genes reflect the methanol tolerance level of the cells. The transcriptional inducer of hps and phi genes is formaldehyde, and not methanol, and introduction of multiple copies of these two genes into B. methanolicus made the cells more tolerant of growth on high methanol concentrations. The recombinant strain also had a significantly higher specific growth rate on methanol than the wild type. While pBM19 is critical for growth on methanol and important for formaldehyde detoxification, the maintenance of this plasmid represents a burden for B. methanolicus when growing on mannitol. Our data contribute to a new and fundamental understanding of the regulation of B. methanolicus methylotrophy. PMID:16585766

Upregulated transcription of plasmid and chromosomal ribulose monophosphate pathway genes is critical for methanol assimilation rate and methanol tolerance in the methylotrophic bacterium Bacillus methanolicus.

PubMed

Jakobsen, Øyvind M; Benichou, Aline; Flickinger, Michael C; Valla, Svein; Ellingsen, Trond E; Brautaset, Trygve

2006-04-01

The natural plasmid pBM19 carries the key mdh gene needed for the oxidation of methanol into formaldehyde by Bacillus methanolicus. Five more genes, glpX, fba, tkt, pfk, and rpe, with deduced roles in the cell primary metabolism, are also located on this plasmid. By using real-time PCR, we show that they are transcriptionally upregulated (6- to 40-fold) in cells utilizing methanol; a similar induction was shown for two chromosomal genes, hps and phi. These seven genes are involved in the fructose bisphosphate aldolase/sedoheptulose bisphosphatase variant of the ribulose monophosphate (RuMP) pathway for formaldehyde assimilation. Curing of pBM19 causes higher methanol tolerance and reduced formaldehyde tolerance, and the methanol tolerance is reversed to wild-type levels by reintroducing mdh. Thus, the RuMP pathway is needed to detoxify the formaldehyde produced by the methanol dehydrogenase-mediated conversion of methanol, and the in vivo transcription levels of mdh and the RuMP pathway genes reflect the methanol tolerance level of the cells. The transcriptional inducer of hps and phi genes is formaldehyde, and not methanol, and introduction of multiple copies of these two genes into B. methanolicus made the cells more tolerant of growth on high methanol concentrations. The recombinant strain also had a significantly higher specific growth rate on methanol than the wild type. While pBM19 is critical for growth on methanol and important for formaldehyde detoxification, the maintenance of this plasmid represents a burden for B. methanolicus when growing on mannitol. Our data contribute to a new and fundamental understanding of the regulation of B. methanolicus methylotrophy.

Chimerism and tolerance without GVHD or engraftment syndrome in HLA-mismatched combined kidney and hematopoietic stem cell transplantation.

PubMed

Leventhal, Joseph; Abecassis, Michael; Miller, Joshua; Gallon, Lorenzo; Ravindra, Kadiyala; Tollerud, David J; King, Bradley; Elliott, Mary Jane; Herzig, Geoffrey; Herzig, Roger; Ildstad, Suzanne T

2012-03-07

The toxicity of chronic immunosuppressive agents required for organ transplant maintenance has prompted investigators to pursue approaches to induce immune tolerance. We developed an approach using a bioengineered mobilized cellular product enriched for hematopoietic stem cells (HSCs) and tolerogenic graft facilitating cells (FCs) combined with nonmyeloablative conditioning; this approach resulted in engraftment, durable chimerism, and tolerance induction in recipients with highly mismatched related and unrelated donors. Eight recipients of human leukocyte antigen (HLA)-mismatched kidney and FC/HSC transplants underwent conditioning with fludarabine, 200-centigray total body irradiation, and cyclophosphamide followed by posttransplant immunosuppression with tacrolimus and mycophenolate mofetil. Subjects ranged in age from 29 to 56 years. HLA match ranged from five of six loci with related donors to one of six loci with unrelated donors. The absolute neutrophil counts reached a nadir about 1 week after transplant, with recovery by 2 weeks. Multilineage chimerism at 1 month ranged from 6 to 100%. The conditioning was well tolerated, with outpatient management after postoperative day 2. Two subjects exhibited transient chimerism and were maintained on low-dose tacrolimus monotherapy. One subject developed viral sepsis 2 months after transplant and experienced renal artery thrombosis. Five subjects experienced durable chimerism, demonstrated immunocompetence and donor-specific tolerance by in vitro proliferative assays, and were successfully weaned off all immunosuppression 1 year after transplant. None of the recipients produced anti-donor antibody or exhibited engraftment syndrome or graft-versus-host disease. These results suggest that manipulation of a mobilized stem cell graft and nonmyeloablative conditioning represents a safe, practical, and reproducible means of inducing durable chimerism and donor-specific tolerance in solid organ transplant recipients.

Acute tolerance to spinally administered morphine compares mechanistically with chronically induced morphine tolerance.

PubMed

Fairbanks, C A; Wilcox, G L

1997-09-01

The mechanistic similarity between acutely and chronically induced morphine tolerance has been previously proposed but remains largely unexplored. Our experiments examined the modulation of acutely induced tolerance to spinally administered morphine by agonists that affect the N-methyl-D-aspartate receptor and nitric oxide synthase systems. Antinociception was detected via the hot water (52.5 degrees C) tail flick test in mice. Intrathecal pretreatment with morphine (40 nmol) produced a 9.6-fold rightward shift in the morphine dose-response curve. This shift confirmed the induction of acute spinal morphine tolerance. Intrathecal copretreatment with the receptor antagonists (competitive and noncompetitive, respectively) dizolcipine (MK801, 3 nmol) or LY235959 (4 pmol) and morphine [40 nmol, intrathecally (i.t.)] attenuated acute tolerance to morphine measured 8 hr later. A 60-min pretreatment of 7-nitroindazole (6 nmol, i.t.), a selective neuronal NOS inhibitor, followed by administration of morphine (40 nmol, i.t.) blocked the induction of morphine tolerance. Intrathecal copretreatment with morphine (40 nmol, i.t.) and agmatine (4 nmol, i.t.), an imidazoline, receptor agonist and putative nitric oxide synthase inhibitor, almost completely abolished acute spinal morphine tolerance. The results of these experiments agree with previous reports using models of chronically induced morphine tolerance. This evidence supports the proposal that the mechanisms responsible for acute morphine tolerance parallel those underlying chronic morphine tolerance. This study attests to the powerful predictive value of acute induction as a model for morphine tolerance.

The Stringent Response Controls Catalases in Pseudomonas aeruginosa and Is Required for Hydrogen Peroxide and Antibiotic Tolerance

PubMed Central

Khakimova, Malika; Ahlgren, Heather G.; Harrison, Joe J.; English, Ann M.

2013-01-01

Pseudomonas aeruginosa, a human opportunistic pathogen, possesses a number of antioxidant defense enzymes under the control of multiple regulatory systems. We recently reported that inactivation of the P. aeruginosa stringent response (SR), a starvation stress response controlled by the alarmone (p)ppGpp, caused impaired antioxidant defenses and antibiotic tolerance. Since catalases are key antioxidant enzymes in P. aeruginosa, we compared the levels of H2O2 susceptibility and catalase activity in P. aeruginosa wild-type and ΔrelA ΔspoT (ΔSR) mutant cells. We found that the SR was required for optimal catalase activity and mediated H2O2 tolerance during both planktonic and biofilm growth. Upon amino acid starvation, induction of the SR upregulated catalase activity. Full expression of katA and katB also required the SR, and this regulation occurred through both RpoS-independent and RpoS-dependent mechanisms. Furthermore, overexpression of katA was sufficient to restore H2O2 tolerance and to partially rescue the antibiotic tolerance of ΔSR cells. All together, these results suggest that the SR regulates catalases and that this is an important mechanism in protecting nutrient-starved and biofilm bacteria from H2O2- and antibiotic-mediated killing. PMID:23457248

Induction of Oral Tolerance with Transgenic Plants Expressing Antigens for Prevention/Treatment of Autoimmune, Allergic and Inflammatory Diseases.

PubMed

Ma, Shengwu; Liao, Yu-Cai; Jevnikar, Anthony M

2015-01-01

The prevalence and incidence of autoimmune and allergic diseases have increased dramatically over the last several decades, especially in the developed world. The treatment of autoimmune and allergic diseases is typically with the use of non-specific immunosuppressive agents that compromise the integrity of the host immune system and therefore, increase the risk of infections. Antigenspecific immunotherapy by reinstating immunological tolerance towards self antigens without compromising immune functions is a much desired goal for the treatment of autoimmune and allergic diseases. Mucosal administration of antigen is a long-recognized method of inducing antigen-specific immune tolerance known as oral tolerance, which is viewed as having promising potential in the treatment of autoimmune and allergic diseases. Plant-based expression and delivery of recombinant antigens provide a promising new platform to induce oral tolerance, having considerable advantages including reduced cost and increased safety. Indeed, in recent years the use of tolerogenic plants for oral tolerance induction has attracted increasing attention, and considerable progress has been made. This review summarizes recent advances in using plants to deliver tolerogens for induction of oral tolerance in the treatment of autoimmune, allergic and inflammatory diseases.

Functional toxicity and tolerance patterns of bioavailable Pd(II), Pt(II), and Rh(III) on suspended Saccharomyces cerevisiae cells assayed in tandem by a respirometric biosensor.

PubMed

Frazzoli, Chiara; Dragone, Roberto; Mantovani, Alberto; Massimi, Cristiana; Campanella, Luigi

2007-12-01

Toxicological implications of exposure to bioavailable platinum group metals, here Pd, Pt, and Rh, are still to be clarified. This study obtained by a biosensor-based method preliminary information on potential effects on cellular metabolism as well as on possible tolerance mechanisms. Aerobic respiration was taken as the toxicological end point to perform tandem tests, namely functional toxicity test and tolerance test. Cells were suspended in the absence of essential constituents for growth. The dose-response curves obtained by exposure (2 h) to the metals (nanogram per gram range) suggested the same mechanisms of action, with Rh showing the greatest curve steepness and the lowest EC50 value. Conservative (95% lower confidence interval) EC10 values were 187, 85 and 51 ng g(-1) for Pt, Pd, and Rh respectively. Tolerance patterns were tested during the same runs. The full tolerance obtained after 12 h of exposure to each metal suggested mitochondrial inhibition of aerobic respiration as a target effect. The hazard rating of the metals in the tolerance test changed in the Rh EC50 range, where Rh showed the lowest toxicity. The observed tolerance might suggest a protective mechanism such as metallothionein induction at concentrations around the EC50 values. The performance of the bioassay was satisfactory, in terms of the limit of detection, repeatability, reproducibility, roboustness, sensibility, and stability; the method's critical uncertainty sources were identified for improvements.

The Johns Hopkins RTR Consortium: A Collaborative Approach to Advance Translational Science and Standardize Clinical Monitoring of Restorative Transplantation - Immunomodulation and Tolerance Induction after VCA using Biologic Agent (cTLA4-Ig) and Donor Bone Marrow Cells

DTIC Science & Technology

2014-10-01

group, Pig 22227, was due to a gastrointestinal bleed , related to either infectious gastroenteritis/colitis or stress ulcer formation. The third... upper extremity transplantation. Delays in progress and incomplete groups will be discussed in detail in Section 5 – Changes/Problems. Table 1...Implemented successfully first clinical protocol for upper extremity transplantation using donor bone marrow cell therapies and tacrolimus

Scientific rationale for the Finnish Allergy Programme 2008-2018: emphasis on prevention and endorsing tolerance.

PubMed

von Hertzen, L C; Savolainen, J; Hannuksela, M; Klaukka, T; Lauerma, A; Mäkelä, M J; Pekkanen, J; Pietinalho, A; Vaarala, O; Valovirta, E; Vartiainen, E; Haahtela, T

2009-05-01

In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both the costs and morbidity of asthma. The time, in the wake of the Asthma Programme, is now opportune for a national allergy programme, particularly as in the past few years, fundamentally more essential data on tolerance and its mechanisms have been published. In this review, the scientific rationale for the Finnish Allergy Programme 2008-2018 is outlined. The focus is on tolerance and how to endorse tolerance at the population level.

MEK inhibition prevents tumour-shed transforming growth factor-β-induced T-regulatory cell augmentation in tumour milieu.

PubMed

Hossain, Dewan M S; Panda, Abir K; Chakrabarty, Sreeparna; Bhattacharjee, Pushpak; Kajal, Kirti; Mohanty, Suchismita; Sarkar, Irene; Sarkar, Diptendra K; Kar, Santosh K; Sa, Gaurisankar

2015-04-01

Tumour progression is associated with immune-suppressive conditions that facilitate the escape of tumour cells from the regimen of immune cells, subsequently paralysing the host defence mechanisms. Induction of CD4(+)  CD25(+)  FoxP3(+) T regulatory (Treg) cells has been implicated in the tumour immune escape mechanism, although the novel anti-cancer treatment strategies targeting Treg cells remain unknown. The focus of this study is to define the interaction between tumour and immune system, i.e. how immune tolerance starts and gradually leads to the induction of adaptive Treg cells in the tumour microenvironment. Our study identified hyperactivated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -signalling as a potential target for reversing Treg cell augmentation in breast cancer patients. In more mechanistic detail, pharmacological inhibitors of MEK/ERK signalling inhibited transforming growth factor-β (TGF-β) production in tumour cells that essentially blocked TGF-β-SMAD3/SMAD4-mediated induction of CD25/interleukin-2 receptor α on CD4(+) T-cell surface. As a result high-affinity binding of interleukin-2 on those cells was prohibited, causing lack of Janus kinase 1 (JAK1)/JAK3-mediated signal transducer and activator of transcription 3 (STAT3)/STAT5 activation required for FoxP3 expression. Finally, for a more radical approach towards a safe MEK inhibitor, we validate the potential of multi-kinase inhibitor curcumin, especially the nano-curcumin made out of pure curcumin with greater bioavailability; in repealing tumour-shed TGF-β-induced Treg cell augmentation. © 2014 Bose Institute.

MEK inhibition prevents tumour-shed transforming growth factor-β-induced T-regulatory cell augmentation in tumour milieu

PubMed Central

Hossain, Dewan M S; Panda, Abir K; Chakrabarty, Sreeparna; Bhattacharjee, Pushpak; Kajal, Kirti; Mohanty, Suchismita; Sarkar, Irene; Sarkar, Diptendra K; Kar, Santosh K; Sa, Gaurisankar

2015-01-01

Tumour progression is associated with immune-suppressive conditions that facilitate the escape of tumour cells from the regimen of immune cells, subsequently paralysing the host defence mechanisms. Induction of CD4+ CD25+ FoxP3+ T regulatory (Treg) cells has been implicated in the tumour immune escape mechanism, although the novel anti-cancer treatment strategies targeting Treg cells remain unknown. The focus of this study is to define the interaction between tumour and immune system, i.e. how immune tolerance starts and gradually leads to the induction of adaptive Treg cells in the tumour microenvironment. Our study identified hyperactivated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -signalling as a potential target for reversing Treg cell augmentation in breast cancer patients. In more mechanistic detail, pharmacological inhibitors of MEK/ERK signalling inhibited transforming growth factor-β (TGF-β) production in tumour cells that essentially blocked TGF-β-SMAD3/SMAD4-mediated induction of CD25/interleukin-2 receptor α on CD4+ T-cell surface. As a result high-affinity binding of interleukin-2 on those cells was prohibited, causing lack of Janus kinase 1 (JAK1)/JAK3-mediated signal transducer and activator of transcription 3 (STAT3)/STAT5 activation required for FoxP3 expression. Finally, for a more radical approach towards a safe MEK inhibitor, we validate the potential of multi-kinase inhibitor curcumin, especially the nano-curcumin made out of pure curcumin with greater bioavailability; in repealing tumour-shed TGF-β-induced Treg cell augmentation. PMID:25284464

Heart grafts tolerized through third-party multipotent adult progenitor cells can be retransplanted to secondary hosts with no immunosuppression.

PubMed

Eggenhofer, Elke; Popp, Felix C; Mendicino, Michael; Silber, Paula; Van't Hof, Wouter; Renner, Philipp; Hoogduijn, Martin J; Pinxteren, Jef; van Rooijen, Nico; Geissler, Edward K; Deans, Robert; Schlitt, Hans J; Dahlke, Marc H

2013-08-01

Multipotent adult progenitor cells (MAPCs) are an adherent stem cell population that belongs to the mesenchymal-type progenitor cell family. Although MAPCs are emerging as candidate agents for immunomodulation after solid organ transplantation, their value requires further validation in a clinically relevant cell therapy model using an organ donor- and organ recipient-independent, third-party cell product. We report that stable allograft survival can be achieved following third-party MAPC infusion in a rat model of fully allogeneic, heterotopic heart transplantation. Furthermore, long-term accepted heart grafts recovered from MAPC-treated animals can be successfully retransplanted to naïve animals without additional immunosuppression. This prolongation of MAPC-mediated allograft acceptance depends upon a myeloid cell population since depletion of macrophages by clodronate abrogates the tolerogenic MAPC effect. We also show that MAPC-mediated allograft acceptance differs mechanistically from drug-induced tolerance regarding marker gene expression, T regulatory cell induction, retransplantability, and macrophage dependence. MAPC-based immunomodulation represents a promising pathway for clinical immunotherapy that has led us to initiate a phase I clinical trial for testing safety and feasibility of third-party MAPC therapy after liver transplantation.

Thymic selection threshold defined by compartmentalization of Ras/MAPK signalling.

PubMed

Daniels, Mark A; Teixeiro, Emma; Gill, Jason; Hausmann, Barbara; Roubaty, Dominique; Holmberg, Kaisa; Werlen, Guy; Holländer, Georg A; Gascoigne, Nicholas R J; Palmer, Ed

2006-12-07

A healthy individual can mount an immune response to exogenous pathogens while avoiding an autoimmune attack on normal tissues. The ability to distinguish between self and non-self is called 'immunological tolerance' and, for T lymphocytes, involves the generation of a diverse pool of functional T cells through positive selection and the removal of overtly self-reactive thymocytes by negative selection during T-cell ontogeny. To elucidate how thymocytes arrive at these cell fate decisions, here we have identified ligands that define an extremely narrow gap spanning the threshold that distinguishes positive from negative selection. We show that, at the selection threshold, a small increase in ligand affinity for the T-cell antigen receptor leads to a marked change in the activation and subcellular localization of Ras and mitogen-activated protein kinase (MAPK) signalling intermediates and the induction of negative selection. The ability to compartmentalize signalling molecules differentially in the cell endows the thymocyte with the ability to convert a small change in analogue input (affinity) into a digital output (positive versus negative selection) and provides the basis for establishing central tolerance.

Recent breakthroughs in the biology of astaxanthin accumulation by microalgal cell.

PubMed

Solovchenko, Alexei E

2015-09-01

Massive accumulation of the secondary ketokarotenoid astaxanthin is a characteristic stress response of certain microalgal species with Haematococcus pluvialis as an illustrious example. The carotenogenic response confers these organisms a remarkable ability to survive in extremely unfavorable environments and makes them the richest source of natural astaxanthin. Exerting a plethora of beneficial effects on human and animal health, astaxanthin is among the most important bioproducts from microalgae. Though our understanding of astaxanthin biosynthesis, induction, and regulation is far from complete, this gap is filling rapidly with new knowledge generated predominantly by application of advanced "omics" approaches. This review focuses on the most recent progress in the biology of astaxanthin accumulation in microalgae including the genomic, proteomic, and metabolomics insights into the induction and regulation of secondary carotenogenesis and its role in stress tolerance of the photosynthetic microorganisms. Special attention is paid to the coupling of the carotenoid and lipid biosynthesis as well as deposition of astaxanthin in the algal cell. The place of the carotenogenic response among the stress tolerance mechanisms is revisited, and possible implications of the new findings for biotechnological production of astaxanthin from microalgae are considered. The potential use of the carotenogenic microalgae as a source not only of value-added carotenoids, but also of biofuel precursors is discussed.

Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.

PubMed

Kudo, Madoka; Kidokoro, Satoshi; Yoshida, Takuya; Mizoi, Junya; Todaka, Daisuke; Fernie, Alisdair R; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2017-04-01

Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene-stacking approach using two transcription factor genes: DEHYDRATION-RESPONSIVE ELEMENT-BINDING 1A (DREB1A) and rice PHYTOCHROME-INTERACTING FACTOR-LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall-related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress-inducible DREB1A downstream genes and cell elongation-related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade-offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought-tolerant transgenic plants. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

CD40L+ CD4+ memory T cells migrate in a CD62P-dependent fashion into reactive lymph nodes and license dendritic cells for T cell priming

PubMed Central

Martín-Fontecha, Alfonso; Baumjohann, Dirk; Guarda, Greta; Reboldi, Andrea; Hons, Miroslav; Lanzavecchia, Antonio; Sallusto, Federica

2008-01-01

There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4+ effector memory T (TEM) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4+ TEM cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4+ TEM cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4+ TEM cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that TEM cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity. PMID:18838544

Food allergen selective thermal processing regimens may change oral tolerance in infancy.

PubMed

Kosti, R I; Triga, M; Tsabouri, S; Priftis, K N

2013-01-01

Food allergy can be considered a failure in the induction of oral tolerance. Recently, great interest has been focused on understanding the mechanisms and the contributing factors of oral tolerance development, hoping for new definitive interventions in the prevention and treatment of food allergy. Given that food processing may modify the properties and the nature of dietary proteins, several food processing methods could affect the allergenicity of these proteins and consequently may favour oral tolerance induction to food allergic children. Indeed, effective thermal food processing regimens of altering food proteins to reduce allergenicity have been recently reported in the literature. This article is mainly focused on the effect of selective thermal processing regimens on the main infant allergenic foods, with a potential clinical relevance on their allergenicity and therefore on oral tolerance induction. In the light of recent findings, the acquisition of tolerance in younger age and consequently the ability of young children to "outgrow" food allergy could be achieved through the application of selective thermal processing regimens on certain allergenic foods. Therefore, the ability of processed foods to circumvent clinical disease and at the same time to have an impact on the immune system and facilitate tolerance induction could be invaluable as a component of a successful therapeutic strategy. The opening in the new avenues of research in the use of processed foods in clinical practice for the amelioration of the impact on the quality of life of patients and possibly in food allergy prevention is warranted. Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.

Granzyme A Deficiency Breaks Immune Tolerance and Promotes Autoimmune Diabetes Through a Type I Interferon-Dependent Pathway.

PubMed

Mollah, Zia U A; Quah, Hong Sheng; Graham, Kate L; Jhala, Gaurang; Krishnamurthy, Balasubramanian; Dharma, Joanna Francisca M; Chee, Jonathan; Trivedi, Prerak M; Pappas, Evan G; Mackin, Leanne; Chu, Edward P F; Akazawa, Satoru; Fynch, Stacey; Hodson, Charlotte; Deans, Andrew J; Trapani, Joseph A; Chong, Mark M W; Bird, Phillip I; Brodnicki, Thomas C; Thomas, Helen E; Kay, Thomas W H

2017-12-01

Granzyme A is a protease implicated in the degradation of intracellular DNA. Nucleotide complexes are known triggers of systemic autoimmunity, but a role in organ-specific autoimmune disease has not been demonstrated. To investigate whether such a mechanism could be an endogenous trigger for autoimmunity, we examined the impact of granzyme A deficiency in the NOD mouse model of autoimmune diabetes. Granzyme A deficiency resulted in an increased incidence in diabetes associated with accumulation of ssDNA in immune cells and induction of an interferon response in pancreatic islets. Central tolerance to proinsulin in transgenic NOD mice was broken on a granzyme A-deficient background. We have identified a novel endogenous trigger for autoimmune diabetes and an in vivo role for granzyme A in maintaining immune tolerance. © 2017 by the American Diabetes Association.

Isolation of ABA-responsive mutants in allohexaploid bread wheat (Triticum aestivum L.): Drawing connections to grain dormancy, preharvest sprouting, and drought tolerance

USDA-ARS?s Scientific Manuscript database

This paper describes the isolation of Wheat ABA-responsive mutants (Warm) in Chinese spring background of allohexaploid Triticum aestivum. The plant hormone abscisic acid (ABA) is required for the induction of seed dormancy, the induction of stomatal closure and drought tolerance, and is associated...

Comparative phenotypic and functional analysis of migratory dendritic cell subsets from human oral mucosa and skin

PubMed Central

van de Ven, Rieneke; Thon, Maria; Gibbs, Susan; de Gruijl, Tanja D.

2017-01-01

Antigen exposure to oral mucosa is generally thought to lead to immune tolerance induction. However, very little is known about the subset composition and function of dendritic cells (DC) migrating from human oral mucosa. Here we show that migratory DC from healthy human gingival explants consist of the same phenotypic subsets in the same frequency distribution as DC migrating from human skin. The gingival CD1a+ Langerhans cell and interstitial DC subsets lacked CXCR4 expression in contrast to their cutaneous counterparts, pointing to different migration mechanisms, consistent with previous observations in constructed skin and gingival equivalents. Remarkably, without any exogenous conditioning, gingival explants released higher levels of inflammatory cytokines than human skin explants, resulting in higher DC migration rates and a superior ability of migrated DC to prime allogeneic T cells and to induce type-1 effector T cell differentiation. From these observations we conclude that rather than an intrinsic ability to induce T cell tolerance, DC migrating from oral mucosa may have a propensity to induce effector T cell immunity and maintain a high state of alert against possible pathogenic intruders in the steady state. These findings may have implications for oral immunization strategies. PMID:28704477

Interleukin-10 Gene-Modified Dendritic Cell-Induced Type 1 Regulatory T Cells Induce Transplant-Tolerance and Impede Graft Versus Host Disease After Allogeneic Stem Cell Transplantation.

PubMed

Wan, Jiangbo; Huang, Fang; Hao, Siguo; Hu, Weiwei; Liu, Chuanxu; Zhang, Wenhao; Deng, Xiaohui; Chen, Linjun; Ma, Liyuan; Tao, Rong

2017-01-01

Tr1 cells can induce peripheral tolerance to self- and foreign antigens, and have been developed as a therapeutic tool for the induction of tolerance to transplanted tissue. We explored the feasibility of generating Tr1 cells by using IL-10 gene-modified recipient DCs (DCLV-IL-10) to stimulate donor naive CD4+ T cells. We also investigated some biological properties of Tr1 cells. DCLV-IL-10 were generated through DCs transduced with a lentivirus vector carrying the IL-10 gene, and Tr1 cells were produced by using DCLV-IL-10 to stimulate naive CD4+ T cells. The effects of Tr1 cells on T-cell proliferation and the occurrence of graft versus host disease (GVHD) following allogeneic stem-cell transplantation (allo-HSCT) were investigated. The DCLV-IL-10-induced Tr1 cells co-expressed LAG-3 and CD49b. Moreover, they also expressed CD4, CD25, and IL-10, but not Foxp3, and secreted significantly higher levels of IL-10 (1,729.36 ± 185.79 pg/mL; P < 0.001) and INF-γ (1,524.48 ± 168.65 pg/mL; P < 0.01) than the control T cells upon the stimulation by allogeneic DCs. Tr1 cells markedly suppressed T-lymphocyte proliferation and the mixed lymphocytic response (MLR) in vitro. The mice used in the allo-HSCT model had longer survival times and lower clinical and pathological GVHD scores than the control mice. IL-10 gene-modified DC-induced Tr1 cells may be used as a potent cellular therapy for the prevention of GVHD after allo-HSCT. © 2017 The Author(s). Published by S. Karger AG, Basel.

Role of Melatonin in Cell-Wall Disassembly and Chilling Tolerance in Cold-Stored Peach Fruit.

PubMed

Cao, Shifeng; Bian, Kun; Shi, Liyu; Chung, Hsiao-Hang; Chen, Wei; Yang, Zhenfeng

2018-06-06

Melatonin reportedly increases chilling tolerance in postharvest peach fruit during cold storage, but information on its effects on cell-wall disassembly in chilling-injured peaches is limited. In this study, we investigated the role of cell-wall depolymerization in chilling-tolerance induction in melatonin-treated peaches. Treatment with 100 μM melatonin alleviated chilling symptoms (mealiness) characterized by a decrease in fruit firmness and increase in juice extractability in treated peaches during storage. The loss of neutral sugars, such as arabinose and galactose, in both the 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA)- and Na 2 CO 3 -soluble fractions was observed at 7 days in treated peaches, but the contents increased after 28 days of storage. Atomic-force-microscopy (AFM) analysis revealed that the polysaccharide widths in the CDTA- and Na 2 CO 3 -soluble fractions in the treated fruit were mainly distributed in a shorter range, as compared with those in the control fruit. In addition, the expression profiles of a series of cell-wall-related genes showed that melatonin treatment maintained the balance between transcripts of PpPME and PpPG, which accompany the up-regulation of several other genes involved in cell-wall disassembly. Taken together, our results suggested that the reduced mealiness by melatonin was probably associated with its positive regulation of numerous cell-wall-modifying enzymes and proteins; thus, the depolymerization of the cell-wall polysaccharides in the peaches treated with melatonin was maintained, and the treated fruit could soften gradually during cold storage.

Cell-Based Therapies in Vascularized Composite Allotransplantation.

PubMed

Vyas, Krishna S; Mohan, Anita T; Morrison, Shane D; Tran, Duy C; Mardini, Samir

2018-06-26

 Dendritic cells (DCs) are bone marrow-derived, professional antigen-presenting cells with tolerogenic function. The ability of DCs to regulate alloantigen-specific T cell responses and to promote tolerance has aligned them ideally for a role in vascularized composite allotransplantation (VCA). In this study, we summarize the current evidence for DC therapies for tolerance induction to alleviate the requirement for chronic immunosuppression.  A comprehensive and structured review of manuscripts published on VCA was performed using the MEDLINE and PubMed databases. All eligible studies published from the year 2000 to 2017 were included in the final results.  Nineteen original preclinical and clinical studies that employed cell therapy for VCA were included in this review. In vivo DC therapy was found to direct the alloimmune response toward either transplant rejection or tolerance in VCA models. While injection of mature DCs rapidly increases T-cell activity in humans and promotes transplant rejection, the injection of immature DCs acts as an immunosuppressant and inhibits T-cell activity. In addition to immature DCs, mesenchymal stem cells were also found to have a positive effect on allotransplantation of solid organs and bone marrow via cytokine expression which decreases the alloreactive effector lymphocytes and increases CD4+/CD25+/FoxP3 Tregs. Despite the promising findings, the efficacy of cell-based therapies varies greatly across studies, partly due to different methods of cell isolation and purification techniques, source, route and timing of administration, and combination immunosuppressive therapy.  Additional research is needed to evaluate the efficacy and safety of DC and other cell-based therapeutic measures in human allotransplant recipients. Future direction will focus on the development of novel methods to reduce immunosuppression and develop more individualized management, as well as the clinical application of basic research in the mechanisms of immunologic tolerance. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Bioprospecting for Genes that Confer Biofuel Tolerance to Escherichia Coli Using a Genomic Library Approach

NASA Astrophysics Data System (ADS)

Tomko, Timothy

Microorganisms are capable of producing advanced biofuels that can be used as 'drop-in' alternatives to conventional liquid fuels. However, vital physiological processes and membrane properties are often disrupted by the presence of biofuel and limit the production yields. In order to make microbial biofuels a competitive fuel source, finding mechanisms for improving resistance to the toxic effects of biofuel production is vital. This investigation aims to identify resistance mechanisms from microorganisms that have evolved to withstand hydrocarbon-rich environments, such as those that thrive near natural oil seeps and in oil-polluted waters. First, using genomic DNA from Marinobacter aquaeolei, we constructed a transgenic library that we expressed in Escherichia coli. We exposed cells to inhibitory levels of pinene, a monoterpene that can serve as a jet fuel precursor with chemical properties similar to existing tactical fuels. Using a sequential strategy of a fosmid library followed by a plasmid library, we were able to isolate a region of DNA from the M. aquaeolei genome that conferred pinene tolerance when expressed in E. coli. We determined that a single gene, yceI, was responsible for the tolerance improvements. Overexpression of this gene placed no additional burden on the host. We also tested tolerance to other monoterpenes and showed that yceI selectively improves tolerance. Additionally, we used genomic DNA from Pseudomonas putida KT2440, which has innate solvent-tolerance properties, to create transgenic libraries in an E. coli host. We exposed cells containing the library to pinene, selecting for genes that improved tolerance. Importantly, we found that expressing the sigma factor RpoD from P. putida greatly expanded the diversity of tolerance genes recovered. With low expression of rpoDP. putida, we isolated a single pinene tolerance gene; with increased expression of the sigma factor our selection experiments returned multiple distinct tolerance mechanisms, including some that have been previously documented and also new mechanisms. Interestingly, high levels of rpoDP. putida, induction resulted in decreased diversity. We found that the tolerance levels provided by some genes are highly sensitive to the level of induction of rpoD P. putida,, while others provide tolerance across a wide range of rpoDP. putida, levels. This method for unlocking diversity in tolerance screening using heterologous sigma factor expression was applicable to both plasmid and fosmid-based transgenic libraries. These results suggest that by controlling the expression of appropriate heterologous sigma factors, we can greatly increase the searchable genomic space within transgenic libraries. This dissertation describes a method of effectively screening genomic DNA from multiple organisms for genes to mitigate biofuel stress and shows how tolerance genes can improve bacterial growth in the presence of toxic biofuel compounds. These identified genes can be targeted in future studies as candidates for use in biofuel production strains to increase biofuel yields.

Cytokine-Conditioned Dendritic Cells Induce Humoral Tolerance to Protein Therapy in Mice

PubMed Central

Sule, Gautam; Suzuki, Masataka; Guse, Kilian; Cela, Racel; Rodgers, John R.

2012-01-01

Abstract A major obstacle in the genetic therapy of inherited metabolic disease is host immune responses to the therapeutic protein. This is best exemplified by inhibitor formation in the protein therapy for hemophilia A. An approach to overcoming this is induction of immunological tolerance to the therapeutic protein. Tolerogenic dendritic cells (DCtols) have been reported to induce tolerance. In addition, cytokines such as interleukin (IL)-10 and transforming growth factor (TGF)-β1 are known to induce tolerance. To model protein therapy, we used ovalbumin (OVA) as antigen in BALB/c mice and their transgenic derivative, DO11.10 mice. In this study we show that adoptive transfer of antigen-pulsed dendritic cells (DCs) treated with a combination of IL-10 and TGF-β1 can suppress the antibody response in mice. Adoptive transfer of cytokine-conditioned DCs in preimmunized mice results in reduction of antibody response in the mice. Furthermore, the effect is antigen specific, as the recipient mice were able to mount a potent antibody response to the control antigen. Last, we show that TGF-β1 and IL-10-conditioned DCs are able to inhibit anti-FVIII antibody responses in FVIII knockout (KO) mice. Analysis of the contribution of IL-10 and TGF-β1 to the DCtol phenotype shows that IL-10 treatment of DCs is sufficient for inducing OVA-specific tolerance in BALB/c mice, but we observed a requirement for treatment with both human TGF-β1 and human IL-10 to significantly inhibit anti-FVIII antibody responses in FVIII KO mice. This paper demonstrates that autologous cell therapy for antigen-targeted immune suppression may be developed to facilitate long-term therapy. PMID:22468961

Active immunotherapy with ultraviolet B-irradiated autologous whole melanoma cells plus DETOX in patients with metastatic melanoma.

PubMed

Eton, O; Kharkevitch, D D; Gianan, M A; Ross, M I; Itoh, K; Pride, M W; Donawho, C; Buzaid, A C; Mansfield, P F; Lee, J E; Legha, S S; Plager, C; Papadopoulos, N E; Bedikian, A Y; Benjamin, R S; Balch, C M

1998-03-01

Our objective was to determine the clinical activity, toxicity, and immunological effects of active immunotherapy using UVB-irradiated (UVR) autologous tumor (AT) cells plus adjuvant DETOX in metastatic melanoma patients. Eligibility included nonanergic patients fully recovered after resection of 5 or more grams of metastatic melanoma. Treatment consisted of intradermal injections of 10(7) UVR-AT plus 0.25 ml of DETOX every 2 weeks x 6, then monthly. Peripheral blood mononuclear cells (PBMCs) were harvested for cytotoxicity assays, and skin testing was performed for delayed-type hypersensitivity (DTH) determinations before the first, fourth, seventh, and subsequent treatments. Forty-two patients were treated, 18 in the adjuvant setting and 24 with measurable disease. Among the latter group, there were two durable responses in soft-tissue sites and in a bone metastasis. Treatment was well tolerated. Thirty-five patients were assessable for immunological parameters; 10 of these patients, including the 2 responders, demonstrated early induction of PBMC cytotoxicity against AT cells that persisted up to 10 months on treatment before falling to background levels. In five of seven patients, the fall-off heralded progressive disease. Late induction of a weak DTH reaction to AT cells was observed in eight patients. Active immunotherapy with UVR-AT + DETOX had modest but definite clinical activity in advanced melanoma. The induction of both PBMC cytotoxicity and DTH reactivity to AT cells supported a specific systemic immune effect of treatment, although the former more closely followed disease course in this study.

Induction of Viable but Nonculturable Salmonella in Exponentially Grown Cells by Exposure to a Low-Humidity Environment and Their Resuscitation by Catalase.

PubMed

Morishige, Yuta; Koike, Atsushi; Tamura-Ueyama, Ai; Amano, Fumio

2017-02-01

Salmonella is a major cause of foodborne disease that sometimes occurs in massive outbreaks around the world. This pathogen is tolerant of low-humidity conditions. We previously described a method for induction of viable but nonculturable (VBNC) Salmonella enterica serovar Enteritidis by treatment with hydrogen peroxide (H 2 O 2 ) and subsequent resuscitation with 0.3 mM sodium pyruvate. Here, we report a new method for the induction of the VBNC state in Salmonella Enteritidis cells, one involving dehydration. Exposure of Salmonella Enteritidis cells to dehydration stress under poor nutritional conditions (0.9% [wt/vol] NaCl) and 10 to 20% relative humidity at room temperature decreased the presence of culturable population to 0.0067%, but respiratory and glucose uptake active populations were maintained at 0.46 and 1.12%, respectively, meaning that approximately 1% may have entered the VBNC state. Furthermore, these VBNC cells could be resuscitated to acquire culturability by incubation with catalase in M9 minimal medium without glucose in a manner dependent on the dose of catalase but not sodium pyruvate. These results suggest that a low-humidity environment could cause Salmonella Enteritidis cells to enter the VBNC state and the cells could then be resuscitated for growth by treatment with catalase, suggesting a potential risk of Salmonella Enteritidis to survive in low water activity foods in the VBNC state and to start regrowth for foodborne illness.

HIV-derived vectors for gene therapy targeting dendritic cells.

PubMed

Rossetti, Maura; Cavarelli, Mariangela; Gregori, Silvia; Scarlatti, Gabriella

2013-01-01

Human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LV) have the potential to mediate stable therapeutic gene transfer. However, similarly to other viral vectors, their benefit is compromised by the induction of an immune response toward transgene-expressing cells that closely mimics antiviral immunity. LV share with the parental HIV the ability to activate dendritic cells (DC), while lack the peculiar ability of subverting DC functions, which is responsible for HIV immune escape. Understanding the interaction between LV and DC, with plasmacytoid and myeloid DC playing fundamental and distinct roles, has paved the way to novel approaches aimed at regulating transgene-specific immune responses. Thanks to the ability to target either DC subsets LV might be a powerful tool to induce immunity (i.e., gene therapy of cancer), cell death (i.e., in HIV/AIDS infection), or tolerance (i.e., gene therapy strategies for monogenic diseases). In this chapter, similarities and differences between the LV-mediated and HIV-mediated induction of immune responses, with specific focus on their interactions with DC, are discussed.

A new concept of skin-associated lymphoid tissue (SALT): UVB light impaired cutaneous immunity reveals a prominent role for cutaneous nerves.

PubMed

Streilein, J W; Alard, P; Niizeki, H

1999-03-01

More than 20 years have passed since the concept that the skin has its own associated immune system was first proposed by Streilein. This proposal was advanced in part on evidence that cutaneous contact hypersensitivity (CH) reactions are closely correlated with Langerhans cells (LC). Recent reports have demonstrated that LC have neural connectivity with cutaneous nerve termini containing calcitonin gene-related peptide (CGRP), suggesting that a link exists between innervation and immune responses in the skin. Here we discuss the neural components which have recently been found to be participants in skin-associated lymphoid tissue (SALT). In part, discovery of a functional link between the nervous system and SALT is based on studies in which cutaneous immunity was impaired by ultraviolet-B radiation (UVR). The deleterious effects of UVR on cutaneous immunity include failed CH induction and promotion of hapten-specific tolerance, effects that are mediated by tumor necrosis factor-alpha and interleukin-10, respectively. The source of these cytokines after UVR appears to be dermal mast cells. Evidence indicates that mast cells are triggered to release these cytokines in response to CGRP, which is released from UVR-damaged cutaneous nerve endings. Moreover, a substance P agonist was able to reverse the deleterious effects of UVR on CH induction, rendering the mice able to develop intense CH. These observations indicate that two cell types not originally included in the SALT concept are critical to the functional integrity of cutaneous immunity: mast cells and cutaneous nerves. We propose that cutaneous nerves dictate whether antigen applied to or arising within skin will lead to sensitivity or tolerance.

Activation of B Cells by a Dendritic Cell-Targeted Oral Vaccine

PubMed Central

Sahay, Bikash; Owen, Jennifer L.; Yang, Tao; Zadeh, Mojgan; Lightfoot, Yaíma L.; Ge, Jun-Wei; Mohamadzadeh, Mansour

2015-01-01

Production of long-lived, high affinity humoral immunity is an essential characteristic of successful vaccination and requires cognate interactions between T and B cells in germinal centers. Within germinal centers, specialized T follicular helper cells assist B cells and regulate the antibody response by mediating the differentiation of B cells into memory or plasma cells after exposure to T cell-dependent antigens. It is now appreciated that local immune responses are also essential for protection against infectious diseases that gain entry to the host by the mucosal route; therefore, targeting the mucosal compartments is the optimum strategy to induce protective immunity. However, because the gastrointestinal mucosae are exposed to large amounts of environmental and dietary antigens on a daily basis, immune regulatory mechanisms exist to favor tolerance and discourage autoimmunity at these sites. Thus, mucosal vaccination strategies must ensure that the immunogen is efficiently taken up by the antigen presenting cells, and that the vaccine is capable of activating humoral and cellular immunity, while avoiding the induction of tolerance. Despite significant progress in mucosal vaccination, this potent platform for immunotherapy and disease prevention must be further explored and refined. Here we discuss recent progress in the understanding of the role of different phenotypes of B cells in the development of an efficacious mucosal vaccine against infectious disease. PMID:24372255

Is the Quantification of Antigen-Specific Basophil Activation a Useful Tool for Monitoring Oral Tolerance Induction in Children With Egg Allergy?

PubMed

Gamboa, P M; Garcia-Lirio, E; Gonzalez, C; Gonzalez, A; Martinez-Aranguren R M; Sanz María, L

2016-01-01

To assess modifications in baseline specific IgE- and anti-IgE- and antigen-specific-mediated basophil activation in egg-allergic children. The values were compared before and after the children completed specific oral tolerance induction (SOTI) with egg. We studied 28 egg-allergic children who completed SOTI with egg. The basophil activation test and specific IgE determinations with egg white, ovalbumin, and ovomucoid were performed in all 28 children. A decrease in antigen-specific activation with egg white, ovalbumin, and ovomucoid was observed only at the 2 lowest concentrations used (5 and 0.05 ng/mL). Baseline activation was higher in patients with multiple food allergies and in those who developed anaphylaxis during SOTI; this activation decreased in both groups after completion of SOTI. A significant decrease was also observed in specific IgE values for egg white, ovalbumin, and ovomucoid after tolerance induction. Food tolerance induction is a specific process for each food that can be mediated by immunologic changes such as a decrease in specific IgE values and in specific and spontaneous basophil activation.

The PD1:PD-L1/2 Pathway from Discovery to Clinical Implementation.

PubMed

Bardhan, Kankana; Anagnostou, Theodora; Boussiotis, Vassiliki A

2016-01-01

The immune system maintains a critically organized network to defend against foreign particles, while evading self-reactivity simultaneously. T lymphocytes function as effectors and play an important regulatory role to orchestrate the immune signals. Although central tolerance mechanism results in the removal of the most of the autoreactive T cells during thymic selection, a fraction of self-reactive lymphocytes escapes to the periphery and pose a threat to cause autoimmunity. The immune system evolved various mechanisms to constrain such autoreactive T cells and maintain peripheral tolerance, including T cell anergy, deletion, and suppression by regulatory T cells (T Regs ). These effects are regulated by a complex network of stimulatory and inhibitory receptors expressed on T cells and their ligands, which deliver cell-to-cell signals that dictate the outcome of T cell encountering with cognate antigens. Among the inhibitory immune mediators, the pathway consisting of the programed cell death 1 (PD-1) receptor (CD279) and its ligands PD-L1 (B7-H1, CD274) and PD-L2 (B7-DC, CD273) plays an important role in the induction and maintenance of peripheral tolerance and for the maintenance of the stability and the integrity of T cells. However, the PD-1:PD-L1/L2 pathway also mediates potent inhibitory signals to hinder the proliferation and function of T effector cells and have inimical effects on antiviral and antitumor immunity. Therapeutic targeting of this pathway has resulted in successful enhancement of T cell immunity against viral pathogens and tumors. Here, we will provide a brief overview on the properties of the components of the PD-1 pathway, the signaling events regulated by PD-1 engagement, and their consequences on the function of T effector cells.

The PD1:PD-L1/2 Pathway from Discovery to Clinical Implementation

PubMed Central

Bardhan, Kankana; Anagnostou, Theodora; Boussiotis, Vassiliki A.

2016-01-01

The immune system maintains a critically organized network to defend against foreign particles, while evading self-reactivity simultaneously. T lymphocytes function as effectors and play an important regulatory role to orchestrate the immune signals. Although central tolerance mechanism results in the removal of the most of the autoreactive T cells during thymic selection, a fraction of self-reactive lymphocytes escapes to the periphery and pose a threat to cause autoimmunity. The immune system evolved various mechanisms to constrain such autoreactive T cells and maintain peripheral tolerance, including T cell anergy, deletion, and suppression by regulatory T cells (TRegs). These effects are regulated by a complex network of stimulatory and inhibitory receptors expressed on T cells and their ligands, which deliver cell-to-cell signals that dictate the outcome of T cell encountering with cognate antigens. Among the inhibitory immune mediators, the pathway consisting of the programed cell death 1 (PD-1) receptor (CD279) and its ligands PD-L1 (B7-H1, CD274) and PD-L2 (B7-DC, CD273) plays an important role in the induction and maintenance of peripheral tolerance and for the maintenance of the stability and the integrity of T cells. However, the PD-1:PD-L1/L2 pathway also mediates potent inhibitory signals to hinder the proliferation and function of T effector cells and have inimical effects on antiviral and antitumor immunity. Therapeutic targeting of this pathway has resulted in successful enhancement of T cell immunity against viral pathogens and tumors. Here, we will provide a brief overview on the properties of the components of the PD-1 pathway, the signaling events regulated by PD-1 engagement, and their consequences on the function of T effector cells. PMID:28018338

Environmental peer pressure: CD4+ T cell help in tolerance and transplantation.

PubMed

Tedesco, Dana; Grakoui, Arash

2018-01-01

The liver participates in a multitude of metabolic functions that are critical for sustaining human life. Despite constant encounters with antigenic-rich intestinal blood, oxidative stress, and metabolic intermediates, there is no appreciable immune response. Interestingly, patients undergoing orthotopic liver transplantation benefit from a high rate of graft acceptance in comparison to other solid organ transplant recipients. In fact, cotransplantation of a donor liver in tandem with a rejection-prone graft increases the likelihood of graft acceptance. A variety of players may account for this phenomenon including the interaction of intrahepatic antigen-presenting cells with CD4 + T cells and the preferential induction of forkhead box P3 (Foxp3) expression on CD4 + T cells following injurious stimuli. Ineffective insult management can cause chronic liver disease, which manifests systemically as the following: antibody-mediated disorders, ineffective antiviral and antibacterial immunity, and gastrointestinal disorders. These sequelae sharing the requirement of CD4 + T cell help to coordinate aberrant immune responses. In this review, we will focus on CD4 + T cell help due to the shared requirements in hepatic tolerance and coordination of extrahepatic immune responses. Overall, intrahepatic deviations from steady state can have deleterious systemic immune outcomes and highlight the liver's remarkable capacity to maintain a balance between tolerance and inflammatory response while simultaneously being inundated with a panoply of antigenic stimuli. Liver Transplantation 24 89-97 2018 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

Coupling of Peripheral Tolerance to Endogenous Interleukin 10 Promotes Effective Modulation of Myelin-Activated T Cells and Ameliorates Experimental Allergic Encephalomyelitis

PubMed Central

Legge, Kevin L.; Min, Booki; Bell, J. Jeremiah; Caprio, Jacque C.; Li, Lequn; Gregg, Randal K.; Zaghouani, Habib

2000-01-01

Several immune-based approaches are being considered for modulation of inflammatory T cells and amelioration of autoimmune diseases. The most recent strategies include simulation of peripheral self-tolerance by injection of adjuvant free antigen, local delivery of cytokines by genetically altered T cells, and interference with the function of costimulatory molecules. Although promising results have been obtained from these studies that define mechanisms of T cell modulation, efficacy, practicality, and toxicity, concerns remain unsolved, thereby justifying further investigations to define alternatives for effective downregulation of aggressive T cells. In prior studies, we demonstrated that an immunoglobulin (Ig) chimera carrying the encephalitogenic proteolipid protein (PLP)1 peptide corresponding to amino acid sequence 139–151 of PLP, Ig-PLP1, is presented to T cells ∼100-fold better than free PLP1. Here, we demonstrate that aggregation endows Ig-PLP1 with an additional feature, namely, induction of interleukin (IL)-10 production by macrophages and dendritic cells, both of which are antigen-presenting cells (APCs). These functions synergize in vivo and drive effective modulation of autoimmunity. Indeed, it is shown that animals with ongoing active experimental allergic encephalomyelitis dramatically reduce the severity of their paralysis when treated with adjuvant free aggregated Ig-PLP1. Moreover, IL-10 displays bystander antagonism on unrelated autoreactive T cells, allowing for reversal of disease involving multiple epitopes. Therefore, aggregated Ig-PLP1 likely brings together a peripheral T cell tolerance mechanism emanating from peptide presentation by APCs expressing suboptimal costimulatory molecules and IL-10 bystander suppression to drive a dual-modal T cell modulation system effective for reversal of autoimmunity involving several epitopes and diverse T cell specificities. PMID:10859329

Epigenetic and molecular profiles of erythroid cells after hydroxyurea treatment in sickle cell anemia

PubMed Central

Steward, Shirley; Howard, Thad A.; Mortier, Nicole; Smeltzer, Matthew; Wang, Yong-Dong; Ware, Russell E.

2011-01-01

Hydroxyurea has been shown to be efficacious for the treatment of sickle cell anemia (SCA), primarily through the induction of fetal hemoglobin (HbF). However, the exact mechanisms by which hydroxyurea can induce HbF remain incompletely defined, although direct transcriptional effects and altered cell cycle kinetics have been proposed. In this study, we investigated potential epigenetic and alternative molecular mechanisms of hydroxyurea-mediated HbF induction by examining methylation patterns within the Gγ-globin promoter and miRNA expression within primary CD71+ erythrocytes of patients with SCA, both at baseline before beginning hydroxyurea therapy and after reaching maximum tolerated dose (MTD). Using both cross-sectional analysis and paired-sample analysis, we found that the highly methylated Gγ-globin promoter was inversely correlated to baseline HbF levels, but only slightly altered by hydroxyurea treatment. Conversely, expression of several specific miRNAs was significantly increased after hydroxyurea treatment, and expression of miR-26b and miR-151-3p were both associated with HbF levels at MTD. The significant associations identified in these studies suggest that methylation may be important for regulation of baseline HbF, but not after hydroxyurea treatment, whereas changes in miRNA expression may be associated with hydroxyurea-mediated HbF induction. This study was registered at ClinicalTrials.gov (NCT00305175). PMID:21921042

TGF-β in tolerance, development and regulation of immunity

PubMed Central

Johnston, Chris J.C.; Smyth, Danielle J.; Dresser, David W.; Maizels, Rick M.

2016-01-01

The TGF-β superfamily is an ancient metazoan protein class which cuts across cell and tissue differentiation, developmental biology and immunology. Its many members are regulated at multiple levels from intricate control of gene transcription, post-translational processing and activation, and signaling through overlapping receptor structures and downstream intracellular messengers. We have been interested in TGF-β homologues firstly as key players in the induction of immunological tolerance, the topic so closely associated with Ray Owen. Secondly, our interests in how parasites may manipulate the immune system of their host has also brought us to study the TGF-β pathway in infections with longlived, essentially tolerogenic, helminth parasites. Finally, within the spectrum of mammalian TGF-β proteins is an exquisitely tightly-regulated gene, anti-Müllerian hormone (AMH), whose role in sex determination underpins the phenotype of freemartin calves that formed the focus of Ray’s seminal work on immunological tolerance. PMID:26617281

INDUCTION OF DONOR-SPECIFIC TRANSPLANTATION TOLERANCE TO SKIN AND CARDIAC ALLOGRAFTS USING MIXED CHIMERISM IN (A + B → A) IN RATS

PubMed Central

Markus, Peter M.; Selvaggi, Gennaro; Cai, Xin; Fung, John J.; Starzl, Thomas E.

2010-01-01

Mixed allogeneic chimerism (A + B → A) was induced in rats by reconstitution of lethally irradiated LEW recipients with a mixture of T-cell depleted (TCD) syngeneic and TCD allogeneic ACI bone marrow. Thirty-seven percent of animals repopulated as stable mixed lymphopoietic chimeras, while the remainder had no detectable allogeneic chimerism. When evaluated for evidence of donor-specific transplantation tolerance, only those recipients with detectable allogeneic lymphoid chimerism exhibited acceptance of donor-specific skin and cardiac allografts. Despite transplantation over a major histocompatibility complex (MHO)- and minor-disparate barrier, animals accepted donor-specific ACI skin and primarily vascularized cardiac allografts permanently, while rejecting third party Brown Norway (BN) grafts. The tolerance induced was also donor-specific in vitro as evidenced by specific hyporeactivity to the allogeneic donor lymphoid elements, yet normal reactivity to MHC-disparate third party rat lymphoid cells. This model for mixed chimerism in the rat will be advantageous to investigate specific transplantation tolerance to primarily vascularized solid organ grafts that can be performed with relative ease in the rat, but not in the mouse, and may provide a method to study the potential existence of organ- or tissue-specific alloantigens in primarily vascularized solid organ allografts. PMID:8162277

The Role of Dendritic Cell Maturation in the Induction of Insulin-Dependent Diabetes Mellitus.

PubMed

Mbongue, Jacques C; Nieves, Hector A; Torrez, Timothy W; Langridge, William H R

2017-01-01

Dendritic cells (DCs) are the dominant class of antigen-presenting cells in humans and are largely responsible for the initiation and guidance of innate and adaptive immune responses involved in maintenance of immunological homeostasis. Immature dendritic cells (iDCs) phagocytize pathogens and toxic proteins and in endosomal vesicles degrade them into small fragments for presentation on major histocompatibility complex (MHC) II receptor molecules to naïve cognate T cells (Th0). In addition to their role in stimulation of immunity, DCs are involved in the induction and maintenance of immune tolerance toward self-antigens. During activation, the iDCs become mature. Maturation begins when the DCs cease taking up antigens and begin to migrate from their location in peripheral tissues to adjacent lymph nodes or the spleen where during their continued maturation the DCs present stored antigens on surface MHCII receptor molecules to naive Th0 cells. During antigen presentation, the DCs upregulate the biosynthesis of costimulatory receptor molecules CD86, CD80, CD83, and CD40 on their plasma membrane. These activated DC receptor molecules bind cognate CD28 receptors presented on the Th0 cell membrane, which triggers DC secretion of IL-12 or IL-10 cytokines resulting in T cell differentiation into pro- or anti-inflammatory T cell subsets. Although basic concepts involved in the process of iDC activation and guidance of Th0 cell differentiation have been previously documented, they are poorly defined. In this review, we detail what is known about the process of DC maturation and its role in the induction of insulin-dependent diabetes mellitus autoimmunity.

Specific oral tolerance induction in childhood.

PubMed

Peters, Rachel L; Dang, Thanh D; Allen, Katrina J

2016-12-01

Food allergy continues to be a significant public health concern for which there are no approved treatments and management strategies primarily include allergen avoidance and pharmacological measures for accidental exposures. Food allergy is thought to result from either a failure to establish oral tolerance or the breakdown of existing oral tolerance, and therefore, experimental preventative and treatment strategies are now aimed at inducing specific oral tolerance. This may occur in infancy prior to the development of food allergy through the optimal timing of dietary exposure (primary oral tolerance induction) or as a treatment for established food allergy through oral immunotherapy (secondary oral tolerance induction). Trials examining the effectiveness of early dietary allergen exposure to prevent food allergy have yielded promising results for peanut allergy but not so for other allergens, although the results of several trials are yet to be published. Although infant feeding guidelines no longer advise to avoid allergenic foods and exposure to food allergens orally is an important step in inducing food tolerance by the immune system, evidence regarding the optimal timing, dose and form of these foods into the infant's diet is lacking. Likewise, oral immunotherapy trials appear promising for inducing desensitization; however, the long-term efficacy in achieving sustained desensitization and optimal protocols to achieve this is unknown. More research is needed in this emerging field. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dual specific oral tolerance induction using interferon gamma for IgE-mediated anaphylactic food allergy and the dissociation of local skin allergy and systemic oral allergy: tolerance or desensitization?

PubMed

Noh, G; Jang, E H

2014-01-01

Specific oral tolerance induction (SOTI) for IgE-mediated food allergy (IFA) can be successfully achieved using interfero gamma (classic SOTI). In this study, a tolerable dose was introduced during tolerance induction with interferon gamma (dual SOTI), and its effectiveness was evaluated. The study population comprised 25 IFA patients. Blood samples were taken for analysis, including complete blood count with differential counts of eosinophils, serum total IgE levels, and specific IgE for allergenic foods. Skin prick tests were conducted with the allergens. Oral food challenges were performed to diagnose IFA. Ten patients received dual SOTI, 5 received classic SOTI, 5 received SOTI without interferon gamma (original SOTI), and 5 were not treated (controls). Patients treated with dual SOTI and classic SOTI using interferon gamma became tolerant to the allergenic food. The tolerable dose was introduced successfully in dual SOTI. It was difficult to proceed with the same dosing protocol used for classic SOTI in cases treated with original SOTI. Following dual SOTI, the systemic reaction to oral intake subsided, but the local skin reaction to contact with the allergenic food persisted. Dual SOTI is an improved protocol for SOTI using interferon gamma for IFA.The local skin reaction and systemic reaction to oral intake were dissociated following dual SOTI. In cases of food allergy, tolerance appears to result from desensitization to allergens.

Peptide immunotherapy in allergic asthma generates IL-10–dependent immunological tolerance associated with linked epitope suppression

PubMed Central

Campbell, John D.; Buckland, Karen F.; McMillan, Sarah J.; Kearley, Jennifer; Oldfield, William L.G.; Stern, Lawrence J.; Grönlund, Hans; van Hage, Marianne; Reynolds, Catherine J.; Boyton, Rosemary J.; Cobbold, Stephen P.; Kay, A. Barry; Altmann, Daniel M.; Larché, Mark

2009-01-01

Treatment of patients with allergic asthma using low doses of peptides containing T cell epitopes from Fel d 1, the major cat allergen, reduces allergic sensitization and improves surrogate markers of disease. Here, we demonstrate a key immunological mechanism, linked epitope suppression, associated with this therapeutic effect. Treatment with selected epitopes from a single allergen resulted in suppression of responses to other (“linked”) epitopes within the same molecule. This phenomenon was induced after peptide immunotherapy in human asthmatic subjects and in a novel HLA-DR1 transgenic mouse model of asthma. Tracking of allergen-specific T cells using DR1 tetramers determined that suppression was associated with the induction of interleukin (IL)-10+ T cells that were more abundant than T cells specific for the single-treatment peptide and was reversed by anti–IL-10 receptor administration. Resolution of airway pathophysiology in this model was associated with reduced recruitment, proliferation, and effector function of allergen-specific Th2 cells. Our results provide, for the first time, in vivo evidence of linked epitope suppression and IL-10 induction in both human allergic disease and a mouse model designed to closely mimic peptide therapy in humans. PMID:19528258

Predominant role of DNA polymerase eta and p53-dependent translesion synthesis in the survival of ultraviolet-irradiated human cells.

PubMed

Lerner, Leticia K; Francisco, Guilherme; Soltys, Daniela T; Rocha, Clarissa R R; Quinet, Annabel; Vessoni, Alexandre T; Castro, Ligia P; David, Taynah I P; Bustos, Silvina O; Strauss, Bryan E; Gottifredi, Vanesa; Stary, Anne; Sarasin, Alain; Chammas, Roger; Menck, Carlos F M

2017-02-17

Genome lesions trigger biological responses that help cells manage damaged DNA, improving cell survival. Pol eta is a translesion synthesis (TLS) polymerase that bypasses lesions that block replicative polymerases, avoiding continued stalling of replication forks, which could lead to cell death. p53 also plays an important role in preventing cell death after ultraviolet (UV) light exposure. Intriguingly, we show that p53 does so by favoring translesion DNA synthesis by pol eta. In fact, the p53-dependent induction of pol eta in normal and DNA repair-deficient XP-C human cells after UV exposure has a protective effect on cell survival after challenging UV exposures, which was absent in p53- and Pol H-silenced cells. Viability increase was associated with improved elongation of nascent DNA, indicating the protective effect was due to more efficient lesion bypass by pol eta. This protection was observed in cells proficient or deficient in nucleotide excision repair, suggesting that, from a cell survival perspective, proper bypass of DNA damage can be as relevant as removal. These results indicate p53 controls the induction of pol eta in DNA damaged human cells, resulting in improved TLS and enhancing cell tolerance to DNA damage, which parallels SOS responses in bacteria. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Anergic self-reactive B cells present self antigen and respond normally to CD40-dependent T-cell signals but are defective in antigen-receptor-mediated functions.

PubMed Central

Eris, J M; Basten, A; Brink, R; Doherty, K; Kehry, M R; Hodgkin, P D

1994-01-01

B-cell tolerance to soluble protein self antigens such as hen egg lysozyme (HEL) is mediated by clonal anergy. Anergic B cells fail to mount antibody responses even in the presence of carrier-primed T cells, suggesting an inability to activate or respond to T helper cells. To investigate the nature of this defect, B cells from tolerant HEL/anti-HEL double-transgenic mice were incubated with a membrane preparation from activated T-cell clones expressing the CD40 ligand. These membranes, together with interleukin 4 and 5 deliver the downstream antigen-independent CD40-dependent B-cell-activating signals required for productive T-B collaboration. Anergic B cells responded to this stimulus by proliferating and secreting antibody at levels comparable to or better than control B cells. Furthermore, anergic B cells presented HEL acquired in vivo and could present the unrelated antigen, conalbumin, targeted for processing via surface IgD. In contrast, the low immunoglobulin receptor levels on anergic B cells were associated with reduced de novo presentation of HEL and a failure to upregulate costimulatory ligands for CD28. These defects in immunoglobulin-receptor-mediated functions could be overcome in vivo, suggesting a number of mechanisms for induction of autoantibody responses. Images PMID:7514304

A phase I study afatinib/carboplatin/paclitaxel induction chemotherapy followed by standard chemoradiation in HPV-negative or high-risk HPV-positive locally advanced stage III/IVa/IVb head and neck squamous cell carcinoma.

PubMed

Chung, Christine H; Rudek, Michelle A; Kang, Hyunseok; Marur, Shanthi; John, Pritish; Tsottles, Nancy; Bonerigo, Sarah; Veasey, Andy; Kiess, Ana; Quon, Harry; Cmelak, Anthony; Murphy, Barbara A; Gilbert, Jill

2016-02-01

Afatinib is an ErbB family receptor inhibitor with efficacy in head and neck squamous cell carcinoma (HNSCC). A phase I trial was conducted to determine the maximally tolerated dose (MTD) of afatinib in combination with carboplatin and paclitaxel as induction chemotherapy (IC). Patients with newly diagnosed, locally advanced HPV-negative or HPV-positive HNSCC with a significant smoking history were enrolled. Afatinib alone was given daily for two weeks as lead-in and subsequently given with carboplatin AUC 6mg/mlmin and paclitaxel 175mg/m(2) every 21days as IC. Afatinib was started at a dose of 20mg daily and dose escalated using a modified Fibonacci design. After completion of IC, afatinib was discontinued and patients received concurrent cisplatin 40mg/m(2) weekly and standard radiation. Toxicity was assessed using CTCAE version 4.0. Seven of nine patients completed afatinib lead-in and IC. Five patients had partial response and two patients had stable disease after IC. Dose level 1 (afatinib 20mg) was well tolerated with one grade 3 (ALT elevation) and one grade 4 (neutropenia) toxicities. However, dose level 2 (afatinib 30mg) was not well tolerated with nine grade 3 (pneumonia, abdominal pain, diarrhea, pancytopenia, and UTI), two grade 4 (sepsis) and one grade 5 (death) toxicities. The MTD of afatinib given with carboplatin AUC 6mg/mlmin and paclitaxel 175mg/m(2) is 20mg daily. Combination of afatinib at doses higher than 20mg with carboplatin and paclitaxel should be administered with caution due to the toxicities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adult Tissue-Derived Stem Cells and Tolerance Induction in Nonhuman Primates for Vascularized Composite Allograft Transplantation

DTIC Science & Technology

2017-10-01

Medicine Bethesda, MD 20817 REPORT DATE: October 2017 TYPE OF REPORT : Annual PREPARED FOR: U.S. Army Medical Research and Materiel Command...contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision...unless so designated by other documentation. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of

Mathematical Modeling of Tuberculosis Bacillary Counts and Cellular Populations in the Organs of Infected Mice

PubMed Central

Bru, Antonio; Cardona, Pere-Joan

2010-01-01

Background Mycobacterium tuberculosis is a particularly aggressive microorganism and the host's defense is based on the induction of cellular immunity, in which the creation of a granulomatous structure has an important role. Methodology We present here a new 2D cellular automata model based on the concept of a multifunctional process that includes key factors such as the chemokine attraction of the cells; the role of innate immunity triggered by natural killers; the presence of neutrophils; apoptosis and necrosis of infected macrophages; the removal of dead cells by macrophages, which induces the production of foamy macrophages (FMs); the life cycle of the bacilli as a determinant for the evolution of infected macrophages; and the immune response. Results The results obtained after the inclusion of two degrees of tolerance to the inflammatory response triggered by the infection shows that the model can cover a wide spectrum, ranging from highly-tolerant (i.e. mice) to poorly-tolerant hosts (i.e. mini-pigs or humans). Conclusions This model suggest that stopping bacillary growth at the onset of the infection might be difficult and the important role played by FMs in bacillary drainage in poorly-tolerant hosts together with apoptosis and innate lymphocytes. It also shows the poor ability of the cellular immunity to control the infection, provides a clear protective character to the granuloma, due its ability to attract a sufficient number of cells, and explains why an already infected host can be constantly reinfected. PMID:20886087

The Gene Expression Profile of CD11c+CD8α− Dendritic Cells in the Pre-Diabetic Pancreas of the NOD Mouse

PubMed Central

Beumer, Wouter; Welzen-Coppens, Jojanneke M. C.; van Helden-Meeuwsen, Cornelia G.; Gibney, Sinead M.; Drexhage, Hemmo A.; Versnel, Marjan A.

2014-01-01

Two major dendritic cell (DC) subsets have been described in the pancreas of mice: The CD11c+CD8α− DCs (strong CD4+ T cell proliferation inducers) and the CD8α+CD103+ DCs (T cell apoptosis inducers). Here we analyzed the larger subset of CD11c+CD8α− DCs isolated from the pancreas of pre-diabetic NOD mice for genome-wide gene expression (validated by Q-PCR) to elucidate abnormalities in underlying gene expression networks. CD11c+CD8α− DCs were isolated from 5 week old NOD and control C57BL/6 pancreas. The steady state pancreatic NOD CD11c+CD8α− DCs showed a reduced expression of several gene networks important for the prime functions of these cells, i.e. for cell renewal, immune tolerance induction, migration and for the provision of growth factors including those for beta cell regeneration. A functional in vivo BrdU incorporation test showed the reduced proliferation of steady state pancreatic DC. The reduced expression of tolerance induction genes (CD200R, CCR5 and CD24) was supported on the protein level by flow cytometry. Also previously published functional tests on maturation, immune stimulation and migration confirm the molecular deficits of NOD steady state DC. Despite these deficiencies NOD pancreas CD11c+CD8α− DCs showed a hyperreactivity to LPS, which resulted in an enhanced pro-inflammatory state characterized by a gene profile of an enhanced expression of a number of classical inflammatory cytokines. The enhanced up-regulation of inflammatory genes was supported by the in vitro cytokine production profile of the DCs. In conclusion, our data show that NOD pancreatic CD11c+CD8α− DCs show various deficiencies in steady state, while hyperreactive when encountering a danger signal such as LPS. PMID:25166904

Ginsenoside Rb2 Alleviates Hepatic Lipid Accumulation by Restoring Autophagy via Induction of Sirt1 and Activation of AMPK.

PubMed

Huang, Qi; Wang, Ting; Yang, Liu; Wang, He-Yao

2017-05-19

Although Panax ginseng is a famous traditional Chinese medicine and has been widely used to treat a variety of metabolic diseases including hyperglycemia, hyperlipidemia, and hepatosteatosis, the effective mediators and molecular mechanisms remain largely unknown. In this study we found that ginsenoside Rb2, one of the major ginsenosides in Panax ginseng, was able to prevent hepatic lipid accumulation through autophagy induction both in vivo and in vitro. Treatment of male db/db mice with Rb2 significantly improved glucose tolerance, decreased hepatic lipid accumulation, and restored hepatic autophagy. In vitro, Rb2 (50 µmol/L) obviously increased autophagic flux in HepG2 cells and primary mouse hepatocytes, and consequently reduced the lipid accumulation induced by oleic acid in combination with high glucose. Western blotting analysis showed that Rb2 partly reversed the high fatty acid in combination with high glucose (OA)-induced repression of autophagic pathways including AMP-activated protein kinase (AMPK) and silent information regulator 1 (sirt1). Furthermore, pharmacological inhibition of the sirt1 or AMPK pathways attenuated these beneficial effects of Rb2 on hepatic autophagy and lipid accumulation. Taken together, these results suggested that Rb2 alleviated hepatic lipid accumulation by restoring autophagy via the induction of sirt1 and activation of AMPK, and resulted in improved nonalcoholic fatty liver disease (NAFLD) and glucose tolerance.

Mediators involved in the immunomodulatory effects of apoptotic cells.

PubMed

Saas, Philippe; Bonnefoy, Francis; Kury-Paulin, Stephanie; Kleinclauss, François; Perruche, Sylvain

2007-07-15

Immunomodulatory properties are attributed to apoptotic cells. These properties have been used to modulate allogeneic immune responses in experimental transplantation settings. In independent studies, apoptotic cell infusion has been shown to favor hematopoietic cell engraftment, to increase heart graft survival, and to delay the lethal onset of graft-versus-host disease (GVHD). The goal of this review was to discuss how apoptotic cell infusion interferes with graft rejection or host rejection (i.e., GVHD) and to focus on the potential mediators or "perpetuators" involved in apoptotic cell-induced immunomodulation. Particular emphasis on apoptotic cell phagocytosis, transforming growth factor (TGF)-beta secretion, and regulatory T cell induction was performed. Stimulating "naturally" immunosuppressive molecules (i.e., TGF-beta) or immunomodulatory cells ("alternatively-activated" macrophages, certain dendritic cell subsets, or regulatory T cells) in a physiological manner by using apoptotic cell infusion can be a promising way to induce tolerance.

Hypo-responsiveness of interleukin-8 production in human embryonic epithelial intestine 407 cells independent of NF-{kappa}B pathway: New lessons from endotoxin and ribotoxic deoxynivalenol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moon, Yuseok; Yang, Hyun; Park, Seung-Hwan

Mucosal epithelium senses external toxic insults and transmits the danger signals into the epithelial cells in order to activate a broad range of inflammatory responses. However, pre-exposure to the commensal endotoxins can induce inflammatory tolerance and maintain the homeostasis without excessive immune responses. We recently reported that ribotoxin deoxynivalenol (DON) and its derivatives elicited the pro-inflammatory response as the mucosal insults in human epithelial cells. Taking the knowledge into consideration, we tested the hypothesis that endotoxin pre-exposure can attenuate ribotoxin-induced epithelial interleukin-8 (IL-8) production via a tolerance mechanism. Pre-exposure to endotoxin repressed IL-8 release and its gene expression. However, inflammatorymore » tolerance was not mediated by the attenuated NF-{kappa}B activation which has been generally recognized as the major mediator of LPS-mediated toll-like receptor (TLR) signaling pathway. Instead, pre-exposure to endotoxin was observed to trigger the delayed induction of peroxisome proliferator-activated receptor gamma (PPAR-{gamma}) which contributed to the diminished IL-8 production in the human epithelial cells. Moreover, endogenous PPAR-{gamma} agonist suppressed toxicant-mediated interleukin-8 production and IL-8 mRNA stability. Taken together, endotoxin induced hypo-production of pro-inflammatory cytokine IL-8 in the human epithelial cells, which was associated with the delayed activation of PPAR-{gamma} expression by pre-existing endotoxin.« less

Mediators involved in the immunomodulatory effects of apoptotic cells

PubMed Central

Saas, Philippe; Bonnefoy, Francis; Kury-Paulin, Stephanie; Kleinclauss, François M.; Perruche, Sylvain

2007-01-01

Immunomodulatory properties are attributed to apoptotic cells. These properties have been used to modulate allogeneic immune responses in experimental transplantation settings. In independent studies, apoptotic cell infusion has been shown to favor hematopoietic cell engraftment, to increase heart graft survival and to delay the lethal onset of graft-versus-host disease (GVHD). The goal of this review was to discuss how apoptotic cell infusion interferes with graft rejection or host rejection (i.e., GVHD) and to focus on the potential mediators or “perpetuators” involved in apoptotic cell-induced immunomodulation. Particular emphasis on apoptotic cell phagocytosis, TGF-β secretion and regulatory T cell induction was performed. Stimulating “naturally” immunosuppressive molecules (i.e., TGF-β) or immunomodulatory cells (“alternatively-activated” macrophages, certain DC subsets or regulatory T cells) in a physiological manner by using apoptotic cell infusion can be a promising way to induce tolerance. PMID:17632410

Heart transplantation: challenges facing the field.

PubMed

Tonsho, Makoto; Michel, Sebastian; Ahmed, Zain; Alessandrini, Alessandro; Madsen, Joren C

2014-05-01

There has been significant progress in the field of heart transplantation over the last 45 years. The 1-yr survival rates following heart transplantation have improved from 30% in the 1970s to almost 90% in the 2000s. However, there has been little change in long-term outcomes. This is mainly due to chronic rejection, malignancy, and the detrimental side effects of chronic immunosuppression. In addition, over the last decade, new challenges have arisen such as increasingly complicated recipients and antibody-mediated rejection. Most, if not all, of these obstacles to long-term survival could be prevented or ameliorated by the induction of transplant tolerance wherein the recipient's immune system is persuaded not to mount a damaging immune response against donor antigens, thus eliminating the need for chronic immunosuppression. However, the heart, as opposed to other allografts like kidneys, appears to be a tolerance-resistant organ. Understanding why organs like kidneys and livers are prone to tolerance induction, whereas others like hearts and lungs are tolerance-resistant, could aid in our attempts to achieve long-term, immunosuppression-free survival in human heart transplant recipients. It could also advance the field of pig-to-human xenotransplantation, which, if successful, would eliminate the organ shortage problem. Of course, there are alternative futures to the field of heart transplantation that may include the application of total mechanical support, stem cells, or bioengineered whole organs. Which modality will be the first to reach the ultimate goal of achieving unlimited, long-term, circulatory support with minimal risk to longevity or lifestyle is unknown, but significant progress in being made in each of these areas.

Heart Transplantation: Challenges Facing the Field

PubMed Central

Tonsho, Makoto; Michel, Sebastian; Ahmed, Zain; Alessandrini, Alessandro; Madsen, Joren C.

2014-01-01

There has been significant progress in the field of heart transplantation over the last 45 years. The 1-yr survival rates following heart transplantation have improved from 30% in the 1970s to almost 90% in the 2000s. However, there has been little change in long-term outcomes. This is mainly due to chronic rejection, malignancy, and the detrimental side effects of chronic immunosuppression. In addition, over the last decade, new challenges have arisen such as increasingly complicated recipients and antibody-mediated rejection. Most, if not all, of these obstacles to long-term survival could be prevented or ameliorated by the induction of transplant tolerance wherein the recipient’s immune system is persuaded not to mount a damaging immune response against donor antigens, thus eliminating the need for chronic immunosuppression. However, the heart, as opposed to other allografts like kidneys, appears to be a tolerance-resistant organ. Understanding why organs like kidneys and livers are prone to tolerance induction, whereas others like hearts and lungs are tolerance-resistant, could aid in our attempts to achieve long-term, immunosuppression-free survival in human heart transplant recipients. It could also advance the field of pig-to-human xenotransplantation, which, if successful, would eliminate the organ shortage problem. Of course, there are alternative futures to the field of heart transplantation that may include the application of total mechanical support, stem cells, or bioengineered whole organs. Which modality will be the first to reach the ultimate goal of achieving unlimited, long-term, circulatory support with minimal risk to longevity or lifestyle is unknown, but significant progress in being made in each of these areas. PMID:24789875

Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration.

PubMed

Rosenkranz, Eva; Maywald, Martina; Hilgers, Ralf-Dieter; Brieger, Anne; Clarner, Tim; Kipp, Markus; Plümäkers, Birgit; Meyer, Sören; Schwerdtle, Tanja; Rink, Lothar

2016-03-01

The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 μg/day (0.3mg/kg body weight) or 30 μg/day (1.5mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 RORγT(+) cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. Copyright © 2015 Elsevier Inc. All rights reserved.

Breaking tolerance in transgenic mice expressing the human TSH receptor A-subunit: thyroiditis, epitope spreading and adjuvant as a 'double edged sword'.

PubMed

McLachlan, Sandra M; Aliesky, Holly A; Chen, Chun-Rong; Chong, Gao; Rapoport, Basil

2012-01-01

Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a "double-edged sword". On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the TSHR) displaying strong self-tolerance.

Breaking Tolerance in Transgenic Mice Expressing the Human TSH Receptor A-Subunit: Thyroiditis, Epitope Spreading and Adjuvant as a ‘Double Edged Sword’

PubMed Central

McLachlan, Sandra M.; Aliesky, Holly A.; Chen, Chun-Rong; Chong, Gao; Rapoport, Basil

2012-01-01

Transgenic mice with the human thyrotropin-receptor (TSHR) A-subunit targeted to the thyroid are tolerant of the transgene. In transgenics that express low A-subunit levels (Lo-expressors), regulatory T cell (Treg) depletion using anti-CD25 before immunization with adenovirus encoding the A-subunit (A-sub-Ad) breaks tolerance, inducing extensive thyroid lymphocytic infiltration, thyroid damage and antibody spreading to other thyroid proteins. In contrast, no thyroiditis develops in Hi-expressor transgenics or wild-type mice. Our present goal was to determine if thyroiditis could be induced in Hi-expressor transgenics using a more potent immunization protocol: Treg depletion, priming with Complete Freund's Adjuvant (CFA) + A-subunit protein and further Treg depletions before two boosts with A-sub-Ad. As controls, anti-CD25 treated Hi- and Lo-expressors and wild-type mice were primed with CFA+ mouse thyroglobulin (Tg) or CFA alone before A-sub-Ad boosting. Thyroiditis developed after CFA+A-subunit protein or Tg and A-sub-Ad boosting in Lo-expressor transgenics but Hi- expressors (and wild-type mice) were resistant to thyroiditis induction. Importantly, in Lo-expressors, thyroiditis was associated with the development of antibodies to the mouse TSHR downstream of the A-subunit. Unexpectedly, we observed that the effect of bacterial products on the immune system is a “double-edged sword”. On the one hand, priming with CFA (mycobacteria emulsified in oil) plus A-subunit protein broke tolerance to the A-subunit in Hi-expressor transgenics leading to high TSHR antibody levels. On the other hand, prior treatment with CFA in the absence of A-subunit protein inhibited responses to subsequent immunization with A-sub-Ad. Consequently, adjuvant activity arising in vivo after bacterial infections combined with a protein autoantigen can break self-tolerance but in the absence of the autoantigen, adjuvant activity can inhibit the induction of immunity to autoantigens (like the TSHR) displaying strong self-tolerance. PMID:22970131

Buprenorphine dose induction in non-opioid-tolerant pre-release prisoners.

PubMed

Vocci, Frank J; Schwartz, Robert P; Wilson, Monique E; Gordon, Michael S; Kinlock, Timothy W; Fitzgerald, Terrence T; O'Grady, Kevin E; Jaffe, Jerome H

2015-11-01

In a previously reported randomized controlled trial, formerly opioid-dependent prisoners were more likely to enter community drug abuse treatment when they were inducted in prison onto buprenorphine/naloxone (hereafter called buprenorphine) than when they received counseling without buprenorphine in prison (47.5% vs. 33.7%, p=0.012) (Gordon et al., 2014). In this communication we report on the results of the induction schedule and the adverse event profile seen in pre-release prisoners inducted onto buprenorphine. This paper examines the dose induction procedure, a comparison of the proposed versus actual doses given per week, and side effects reported for 104 adult participants who were randomized to buprenorphine treatment in prison. Self-reported side effects were analyzed using generalized estimated equations to determine changes over time in side effects. Study participants were inducted onto buprenorphine at a rate faster than the induction schedule. Of the 104 (72 males, 32 females) buprenorphine recipients, 64 (37 males, 27 females) remained on medication at release from prison. Nine participants (8.6%) discontinued buprenorphine because of unpleasant opioid side effects. There were no serious adverse events reported during the in-prison phase of the study. Constipation was the most frequent symptom reported (69 percent). Our findings suggest that buprenorphine administered to non-opioid-tolerant adults should be started at a lower, individualized dose than customarily used for adults actively using opioids, and that non-opioid-tolerant pre-release prisoners can be successfully inducted onto therapeutic doses prior to release. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

In vivo exposure to ozone produces an increase in a 72-kDa heat shock protein in guinea pigs.

PubMed

Su, W Y; Gordon, T

1997-09-01

Although several lines of evidence have suggested that oxidizing agents can induce heat shock proteins (HSPs) in vitro, little is known about the induction of HSPs during in vivo exposure to oxidants. Guinea pigs were exposed to ozone for 6 h and euthanized up to 72 h later. Proteins from lavage cells and lung tissue were characterized by immunoblotting with 72- and 73/72-kDa HSP monoclonal antibodies. Although 73-kDa HSP was expressed constituitively in lung tissue, it was not affected by ozone. In contrast, 72-kDa HSP was significantly increased in lavage cells and lung tissue of animals exposed to 0.4 and 0.66 parts/million of ozone. Both heat treatment and arsenite induced 72-kDa HSP in cultured alveolar macrophages. The increase in 72-kDa HSP in the lavage cell pellet peaked at 24 h after ozone, whereas the influx of polymorphonuclear leukocytes peaked at 4 h. Examination of the induction of HSPs by ozone may provide clues to the development of ozone tolerance in humans and animals.

Role of Maternal Dietary Peanut Exposure in Development of Food Allergy and Oral Tolerance.

PubMed

Järvinen, Kirsi M; Westfall, Jennifer; De Jesus, Magdia; Mantis, Nicholas J; Carroll, Jessica A; Metzger, Dennis W; Sampson, Hugh A; Berin, M Cecilia

2015-01-01

The impact of maternal ingestion of peanut during pregnancy and lactation on an offspring's risk for peanut allergy is under debate. To investigate the influence of maternal dietary peanut exposure and breast milk on an offspring's allergy risk. Preconceptionally peanut-exposed C3H/HeJ females were either fed or not fed peanut during pregnancy and lactation. The offsprings' responses to peanut sensitization or oral tolerance induction by feeding antigen prior to immunization were assessed. We also assessed the impact of immune murine milk on tolerance induction pre- or post-weaning. For antigen uptake studies, mice were gavaged with fluorescent peanut in the presence or absence of immune murine milk; Peyer's patches were harvested for immunostaining. Preconceptional peanut exposure resulted in the production of varying levels of maternal antibodies in serum (and breast milk), which were transferred to the offspring. Despite this, maternal peanut exposure either preconceptionally or during pregnancy and lactation, when compared to no maternal exposure, had no impact on peanut allergy. When offspring were fed peanut directly, dose-dependent tolerance induction, unaltered by maternal feeding of peanut, was seen. Although peanut uptake into the gut-associated lymphoid tissues was enhanced by immune milk as compared to naïve milk, tolerance induction was not affected by the co-administration of immune milk either pre- or post-weaning. Maternal peanut exposure during pregnancy and lactation has no impact on the development of peanut allergy in the offspring. Tolerance to peanut can be induced early, even pre-weaning, by giving moderate amounts of peanut directly to the infant, and this is neither enhanced nor impaired by concurrent exposure to immune milk.

Functions of TGF-β-exposed plasmacytoid dendritic cells.

PubMed

Saas, Philippe; Perruche, Sylvain

2012-01-01

Plasmacytoid dendritic cells (pDCs) belong to the family of dendritic cells and possess specific features that distinguish them from conventional dendritic cells. For instance, pDC are the main interferon-alpha-secreting cells. Plasmacytoid dendritic cells exert both proinflammatory and regulatory functions. This is attested by the involvement of pDC through interferon-alpha secretion in several autoimmune diseases, and by the implication of pDC in tolerance. The same is true for TGF-β that plays a dual role in inflammation. In this review, we discuss recent data on pDC and TGF-β interactions. As with many cell types, pDCs are able to respond to TGF-β using the classic Smad signaling pathway. In addition, pDCs are capable to secrete TGF-β, in particular in response to TGF-β exposure. Exposure of pDCs to TGF-β prevents type I interferon secretion in response to TLR7/9 ligands. In contrast, the consequences of TGF-β on the antigen-presenting cell capacities of pDC are less clear, since TGF-β-exposed pDCs may lead to both regulatory T-cell and interleukin-17-secreting cell polarization. Here, we discuss the factors that may influence this polarization. We also discuss how pDCs exposed to TGF-β may participate in tolerance induction and maintenance, or, on the contrary, in autoimmune diseases.

TCR revision generates functional CD4+ T cells1

PubMed Central

Hale, J. Scott; Wubeshet, Maramawit; Fink, Pamela J.

2010-01-01

CD4+Vβ5+ peripheral T cells in B6 mice respond to encounter with a peripherally-expressed endogenous superantigen by undergoing either deletion or TCR revision. In this latter process, cells lose surface Vβ5 expression and undergo RAG-dependent rearrangement of endogenous TCRβ genes, driving surface expression of novel TCRs. While post-revision CD4+Vβ5−TCRβ+ T cells accumulate with age in Vβ5 transgenic mice and bear a diverse TCR Vβ repertoire, it is unknown whether they respond to homeostatic and antigenic stimuli, and thus may benefit the host. We now demonstrate that post-revision cells are functional. These cells have a high rate of steady-state homeostatic proliferation in situ and they undergo extensive MHC class II-dependent lymphopenia-induced proliferation. Importantly, post-revision cells do not proliferate in response to the tolerizing superantigen, implicating TCR revision as a mechanism of tolerance induction and demonstrating that TCR-dependent activation of post-revision cells is not driven by the transgene-encoded receptor. Post-revision cells proliferate extensively to commensal bacterial Ags and can generate I-Ab-restricted responses to Ag by producing IFNγ following Listeria monocytogenes challenge. These data show that rescued post-revision T cells are responsive to homeostatic signals and recognize self and foreign peptides in the context of self MHC, and are thus useful to the host. PMID:20971922

TCR revision generates functional CD4+ T cells.

PubMed

Hale, J Scott; Wubeshet, Maramawit; Fink, Pamela J

2010-12-01

CD4(+)Vβ5(+) peripheral T cells in C57BL/6 mice respond to encounter with a peripherally expressed endogenous superantigen by undergoing either deletion or TCR revision. In this latter process, cells lose surface Vβ5 expression and undergo RAG-dependent rearrangement of endogenous TCRβ genes, driving surface expression of novel TCRs. Although postrevision CD4(+)Vβ5(-)TCRβ(+) T cells accumulate with age in Vβ5 transgenic mice and bear a diverse TCR Vβ repertoire, it is unknown whether they respond to homeostatic and antigenic stimuli and thus may benefit the host. We demonstrate in this study that postrevision cells are functional. These cells have a high rate of steady-state homeostatic proliferation in situ, and they undergo extensive MHC class II-dependent lymphopenia-induced proliferation. Importantly, postrevision cells do not proliferate in response to the tolerizing superantigen, implicating TCR revision as a mechanism of tolerance induction and demonstrating that TCR-dependent activation of postrevision cells is not driven by the transgene-encoded receptor. Postrevision cells proliferate extensively to commensal bacterial Ags and can generate I-A(b)-restricted responses to Ag by producing IFN-γ following Listeria monocytogenes challenge. These data show that rescued postrevision T cells are responsive to homeostatic signals and recognize self- and foreign peptides in the context of self-MHC and are thus useful to the host.

Aminoethyl nitrate – the novel super nitrate?

PubMed Central

Bauersachs, Johann

2009-01-01

Long-term use of most organic nitrates is limited by development of tolerance, induction of oxidative stress and endothelial dysfunction. In this issue of the BJP, Schuhmacher et al. characterized a novel class of organic nitrates with amino moieties (aminoalkyl nitrates). Aminoethyl nitrate was identified as a novel organic mononitrate with high potency but devoid of induction of mitochondrial oxidative stress. Cross-tolerance to nitroglycerin or the endothelium-dependent agonist acetylcholine after in vivo treatment was not observed. Like all nitrates, aminoethyl nitrate induced vasorelaxation by activation of soluble guanylate cyclase. Thus, in contrast to the prevailing view, high potency in an organic nitrate is not necessarily accompanied by induction of oxidative stress or endothelial dysfunction. This work from Daiber's group is an important step forward in the understanding of nitrate bioactivation, tolerance phenomena and towards the development of better organic nitrates for clinical use. PMID:19732062

Tolerance of Escherichia coli to Fluoroquinolone Antibiotics Depends on Specific Components of the SOS Response Pathway

PubMed Central

Theodore, Alyssa; Lewis, Kim; Vulić, Marin

2013-01-01

Bacteria exposed to bactericidal fluoroquinolone (FQ) antibiotics can survive without becoming genetically resistant. Survival of these phenotypically resistant cells, commonly called “persisters,” depends on the SOS gene network. We have examined mutants in all known SOS-regulated genes to identify functions essential for tolerance in Escherichia coli. The absence of DinG and UvrD helicases and the Holliday junction processing enzymes RuvA and RuvB leads to a decrease in survival. Analysis of the respective mutants indicates that, in addition to repair of double-strand breaks, tolerance depends on the repair of collapsed replication forks and stalled transcription complexes. Mutation in recF results in increased survival, which identifies RecAF recombination as a poisoning mechanism not previously linked to FQ lethality. DinG acts upstream of SOS promoting its induction, whereas RuvAB participates in repair only. UvrD directly promotes all repair processes initiated by FQ-induced damage and prevents RecAF-dependent misrepair, making it one of the crucial SOS functions required for tolerance. PMID:24077306

Tolerance of Escherichia coli to fluoroquinolone antibiotics depends on specific components of the SOS response pathway.

PubMed

Theodore, Alyssa; Lewis, Kim; Vulic, Marin

2013-12-01

Bacteria exposed to bactericidal fluoroquinolone (FQ) antibiotics can survive without becoming genetically resistant. Survival of these phenotypically resistant cells, commonly called "persisters," depends on the SOS gene network. We have examined mutants in all known SOS-regulated genes to identify functions essential for tolerance in Escherichia coli. The absence of DinG and UvrD helicases and the Holliday junction processing enzymes RuvA and RuvB leads to a decrease in survival. Analysis of the respective mutants indicates that, in addition to repair of double-strand breaks, tolerance depends on the repair of collapsed replication forks and stalled transcription complexes. Mutation in recF results in increased survival, which identifies RecAF recombination as a poisoning mechanism not previously linked to FQ lethality. DinG acts upstream of SOS promoting its induction, whereas RuvAB participates in repair only. UvrD directly promotes all repair processes initiated by FQ-induced damage and prevents RecAF-dependent misrepair, making it one of the crucial SOS functions required for tolerance.

Forever young: Mechanisms of natural anoxia tolerance and potential links to longevity

PubMed Central

Krivoruchko, Anastasia

2010-01-01

While mammals cannot survive oxygen deprivation for more than a few minutes without sustaining severe organ damage, some animals have mastered anaerobic life. Freshwater turtles belonging to the Trachemys and Chrysemys genera are the champion facultative anaerobes of the vertebrate world, often surviving without oxygen for many weeks at a time. The physiological and biochemical mechanisms that underlie anoxia tolerance in turtles include profound metabolic rate depression, post-translational modification of proteins, strong antioxidant defenses, activation of specific stress-responsive transcription factors, and enhanced expression of cyto-protective proteins. Turtles are also known for their incredible longevity and display characteristics of “negligible senescence.” We propose that the robust stress-tolerance mechanisms that permit long term anaerobiosis by turtles may also support the longevity of these animals. Many of the mechanisms involved in natural anoxia tolerance, such as hypometabolism or the induction of various protective proteins/pathways, have been shown to play important roles in mammalian oxygen-related diseases and improved understanding of how cells survive without oxygen could aid in the understanding and treatment of various pathological conditions that involve hypoxia or oxidative stress. In the present review we discuss the recent advances made in understanding the molecular nature of anoxia tolerance in turtles and the potential links between this tolerance and longevity. PMID:20716943

Premise and promise of mesenchymal stem cell-based therapies in clinical vascularized composite allotransplantation.

PubMed

Schweizer, Riccardo; Gorantla, Vijay S; Plock, Jan A

2015-12-01

Over the past decade, clinical vascularized composite allotransplantation (VCA) has enabled functional and quality of life restoration in a wide range of indications secondary to devastating tissue loss. However, the spectre of toxicity and long-term complications of chronic immunosuppression has curtailed the momentum of VCA. This study summarizes the literature evidence behind successful mesenchymal stem cell (MSC)-based cell therapies highlighting their multipronged immunomodulatory, restorative and regenerative characteristics with special emphasis towards VCA applications. Experimental and clinical studies in solid organs and VCA have confirmed that MSCs facilitate immunosuppression-free allograft survival or tolerance, stimulate peripheral nerve regeneration, attenuate ischaemia-reperfusion injury, and improve tissue healing after surgery. It has been hypothesized that MSC-induced long-term operational tolerance in experimental VCA is mediated by induction of mixed donor-specific chimerism and regulatory T-cell mechanisms. All these characteristics of MSCs could thus help expand the scope and clinical feasibility of VCA. Cellular therapies, especially those focusing on MSCs, are emerging in solid organ transplantation including VCA. Although some clinical trials have begun to assess the effects of MSCs in solid organ transplantation, much scientific domain remains uncharted, especially for VCA.

AHR Activation Is Protective against Colitis Driven by T Cells in Humanized Mice.

PubMed

Goettel, Jeremy A; Gandhi, Roopali; Kenison, Jessica E; Yeste, Ada; Murugaiyan, Gopal; Sambanthamoorthy, Sharmila; Griffith, Alexandra E; Patel, Bonny; Shouval, Dror S; Weiner, Howard L; Snapper, Scott B; Quintana, Francisco J

2016-10-25

Existing therapies for inflammatory bowel disease that are based on broad suppression of inflammation result in variable clinical benefit and unwanted side effects. A potential therapeutic approach for promoting immune tolerance is the in vivo induction of regulatory T cells (Tregs). Here we report that activation of the aryl hydrocarbon receptor using the non-toxic agonist 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) induces human Tregs in vitro that suppress effector T cells through a mechanism mediated by CD39 and Granzyme B. We then developed a humanized murine system whereby human CD4 + T cells drive colitis upon exposure to 2,4,6-trinitrobenzenesulfonic acid and assessed ITE as a potential therapeutic. ITE administration ameliorated colitis in humanized mice with increased CD39, Granzyme B, and IL10-secreting human Tregs. These results develop an experimental model to investigate human CD4 + T responses in vivo and identify the non-toxic AHR agonist ITE as a potential therapy for promoting immune tolerance in the intestine. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Tumour necrosis factor α (TNF)–TNF receptor 1-inducible cytoprotective proteins in the mouse liver: relevance of suppressors of cytokine signalling

PubMed Central

Sass, Gabriele; Shembade, Noula D.; Tiegs, Gisa

2004-01-01

TNF (tumour necrosis factor α) induces tolerance towards itself in experimental liver injury. Tolerance induction has been shown to be dependent on TNFR1 (TNF receptor 1) signalling, but mechanisms and mediators of TNF-induced hepatic tolerance are unknown. We investigated the TNF-inducible gene-expression profile in livers of TNFR2−/− mice, using cDNA array technology. We found that, out of 793 investigated genes involved in inflammation, cell cycle and signal transduction, 282 were expressed in the mouse liver in response to TNF via TNFR1. Among those, expression of 78 genes was induced, while expression of 60 genes was reduced. We investigated further the cellular expression of the 27 most prominently induced genes, and found that 20 of these genes were up-regulated directly in parenchymal liver cells, representing potentially protective proteins and possible mediators of TNF tolerance. In vitro experiments revealed that overexpression of SOCS1 (silencer of cytokine signalling 1), a member of the SOCS family of proteins, as well as of HO-1 (haem oxygenase-1), but not of SOCS2 or SOCS3, protected isolated primary mouse hepatocytes from TNF-induced apoptosis. The identification of protective genes in hepatocytes is the prerequisite for future development of gene therapies for immune-mediated liver diseases. PMID:15554901

Cross-induction of detoxification genes by environmental xenobiotics and insecticides in the mosquito Aedes aegypti: impact on larval tolerance to chemical insecticides.

PubMed

Poupardin, Rodolphe; Reynaud, Stéphane; Strode, Clare; Ranson, Hilary; Vontas, John; David, Jean-Philippe

2008-05-01

The effect of exposure of Aedes aegypti larvae to sub-lethal doses of the pyrethroid insecticide permethrin, the organophosphate temephos, the herbicide atrazine, the polycyclic aromatic hydrocarbon fluoranthene and the heavy metal copper on their subsequent tolerance to insecticides, detoxification enzyme activities and expression of detoxification genes was investigated. Bioassays revealed a moderate increase in larval tolerance to permethrin following exposure to fluoranthene and copper while larval tolerance to temephos increased moderately after exposure to atrazine, copper and permethrin. Cytochrome P450 monooxygenases activities were induced in larvae exposed to permethrin, fluoranthene and copper while glutathione S-transferase activities were induced after exposure to fluoranthene and repressed after exposure to copper. Microarray screening of the expression patterns of all detoxification genes following exposure to each xenobiotic with the Aedes Detox Chip identified multiple genes induced by xenobiotics and insecticides. Further expression studies using real-time quantitative PCR confirmed the induction of multiple CYP genes and one carboxylesterase gene by insecticides and xenobiotics. Overall, this study reveals the potential of xenobiotics found in polluted mosquito breeding sites to affect their tolerance to insecticides, possibly through the cross-induction of particular detoxification genes. Molecular mechanisms involved and impact on mosquito control strategies are discussed.

Yeast adapt to near-freezing temperatures by STRE/Msn2,4-dependent induction of trehalose synthesis and certain molecular chaperones.

PubMed

Kandror, Olga; Bretschneider, Nancy; Kreydin, Evgeniy; Cavalieri, Duccio; Goldberg, Alfred L

2004-03-26

Virtually nothing is known about the biochemical adaptations in eukaryotic cells that may enhance survival at low temperatures or upon freezing. Here we demonstrate an adaptive response in yeast that is activated below 10 degrees C and increases tolerance to low temperatures and freezing. This response involves a dramatic accumulation of the chemical chaperone trehalose and induction of trehalose-synthesizing enzymes (Tps1, Tps2) and certain heat shock proteins (Hsp104, Hsp42, Hsp12, Ssa4). mRNAs for these proteins increase dramatically below 10 degrees C and even at 0 degrees C. Their expression requires Msn2,4 transcription factors but also involves marked mRNA stabilization. Upon return to 30 degrees C, TPS1, TPS2, and HSP104 mRNAs, trehalose levels and tolerance to freezing fall dramatically within minutes. Mutants lacking trehalose or Msn2,4 die more rapidly at 0 degrees C and upon freezing. Thus, below 10 degrees C, yeast show an adaptive response that sustains viability at low or freezing temperatures, which are commonly encountered in natural environments and laboratory refrigerators.

Involvement of Superoxide Dismutases in the Response of Escherichia coli to Selenium Oxides

PubMed Central

Bébien, Magali; Lagniel, Gilles; Garin, Jérôme; Touati, Danièle; Verméglio, André; Labarre, Jean

2002-01-01

Selenium can provoke contrasting effects on living organisms. It is an essential trace element, and low concentrations have beneficial effects, such as the reduction of the incidence of cancer. However, higher concentrations of selenium salts can be toxic and mutagenic. The bases for both toxicity and protection are not clearly understood. To provide insights into these mechanisms, we analyzed the proteomic response of Escherichia coli cells to selenate and selenite treatment under aerobic conditions. We identified 23 proteins induced by both oxides and ca. 20 proteins specifically induced by each oxide. A striking result was the selenite induction of 8 enzymes with antioxidant properties, particularly the manganese and iron superoxide dismutases (SodA and SodB). The selenium inductions of sodA and sodB were controlled by the transcriptional regulators SoxRS and Fur, respectively. Strains with decreased superoxide dismutase activities were severely impaired in selenium oxide tolerance. Pretreatment with a sublethal selenite concentration triggered an adaptive response dependent upon SoxRS, conferring increased selenite tolerance. Altogether, our data indicate that superoxide dismutase activity is essential for the cellular defense against selenium salts, suggesting that superoxide production is a major mechanism of selenium toxicity under aerobic conditions. PMID:11872706

Some Factors Influencing Acid Production by an Oxytetracycline-Resistant Strain of Streptococcus lactis1

PubMed Central

Mikolajcik, E. M.; Harper, W. J.; Gould, I. A.

1963-01-01

Induction of oxytetracycline resistance in a strain of Streptococcus lactis caused this organism to display reduced acid production, salt tolerance, pyruvate synthesis, growth at alkaline pH, and a loss in ability to produce ammonia from arginine. α-Ketoglutaric and oxaloacetic acids were found to accumulate in the growth medium of resistant cells, in contrast to none in the medium of susceptible cells. No free arginine could be detected in the intracellular fraction of resistant cells, but arginine was present in the intracellular fraction of susceptible cells and decreased in concentration upon the addition of oxytetracycline to the growth medium. Depressed acid production in milk by the oxytetracycline resistant strain is evidently a consequence of the inability of this organism to metabolize arginine effectively. PMID:14063784

Activation of FoxM1 Revitalizes the Replicative Potential of Aged β-Cells in Male Mice and Enhances Insulin Secretion

PubMed Central

Golson, Maria L.; Dunn, Jennifer C.; Maulis, Matthew F.; Dadi, Prasanna K.; Osipovich, Anna B.; Magnuson, Mark A.; Jacobson, David A.

2015-01-01

Type 2 diabetes incidence increases with age, while β-cell replication declines. The transcription factor FoxM1 is required for β-cell replication in various situations, and its expression declines with age. We hypothesized that increased FoxM1 activity in aged β-cells would rejuvenate proliferation. Induction of an activated form of FoxM1 was sufficient to increase β-cell mass and proliferation in 12-month-old male mice after just 2 weeks. Unexpectedly, at 2 months of age, induction of activated FoxM1 in male mice improved glucose homeostasis with unchanged β-cell mass. Cells expressing activated FoxM1 demonstrated enhanced glucose-stimulated Ca2+ influx, which resulted in improved glucose tolerance through enhanced β-cell function. Conversely, our laboratory has previously demonstrated that mice lacking FoxM1 in the pancreas display glucose intolerance or diabetes with only a 60% reduction in β-cell mass, suggesting that the loss of FoxM1 is detrimental to β-cell function. Ex vivo insulin secretion was therefore examined in size-matched islets from young mice lacking FoxM1 in β-cells. Foxm1-deficient islets indeed displayed reduced insulin secretion. Our studies reveal that activated FoxM1 increases β-cell replication while simultaneously enhancing insulin secretion and improving glucose homeostasis, making FoxM1 an attractive therapeutic target for diabetes. PMID:26251404

Maternal alloantibodies induce a postnatal immune response that limits engraftment following in utero hematopoietic cell transplantation in mice

PubMed Central

Merianos, Demetri J.; Tiblad, Eleonor; Santore, Matthew T.; Todorow, Carlyn A.; Laje, Pablo; Endo, Masayuki; Zoltick, Philip W.; Flake, Alan W.

2009-01-01

The lack of fetal immune responses to foreign antigens, i.e., fetal immunologic tolerance, is the most compelling rationale for prenatal stem cell and gene therapy. However, the frequency of engraftment following in utero hematopoietic cell transplantation (IUHCT) in the murine model is reduced in allogeneic, compared with congenic, recipients. This observation supports the existence of an immune barrier to fetal transplantation and challenges the classic assumptions of fetal tolerance. Here, we present evidence that supports the presence of an adaptive immune response in murine recipients of IUHCT that failed to maintain engraftment. However, when IUHCT recipients were fostered by surrogate mothers, they all maintained long-term chimerism. Furthermore, we have demonstrated that the cells responsible for rejection of the graft were recipient in origin. Our observations suggest a mechanism by which IUHCT-dependent sensitization of the maternal immune system and the subsequent transmission of maternal alloantibodies to pups through breast milk induces a postnatal adaptive immune response in the recipient, which, in turn, results in the ablation of engraftment after IUHCT. Finally, we showed that non-fostered pups that maintained their chimerism had higher levels of Tregs as well as a more suppressive Treg phenotype than their non-chimeric, non-fostered siblings. This study resolves the apparent contradiction of induction of an adaptive immune response in the pre-immune fetus and confirms the potential of actively acquired tolerance to facilitate prenatal therapeutic applications. PMID:19652363

Antigen-specific, CD4+CD25+ regulatory T cell clones induced in Peyer's patches.

PubMed

Tsuji, Noriko M; Mizumachi, Koko; Kurisaki, Jun-Ichi

2003-04-01

Since intestine is exposed to numerous exogenous antigens such as food and commensal bacteria, the organ bears efficient mechanisms for establishment of tolerance and induction of regulatory T cells (T(reg)). Intestinal and inducible T(reg) include T(r)1-like and T(h)3 cells whose major effector molecules are IL-10 and transforming growth factor (TGF)-beta. These antigen-specific T(reg) are expected to become clinical targets to modify the inflammatory immune response associated with allergy, autoimmune diseases and transplantation. In the present study, we characterized the antigen-specific T(reg) induced in the intestine by orally administering high-dose beta-lactoglobulin (BLG) to BALB/c mice. Seven days after feeding, only Peyer's patch (PP) cells among different organs exerted significant suppressive effect on antibody production upon in vitro BLG stimulation. This suppressive effect was also prominent in six BLG-specific CD4(+) T cell clones (OPP1-6) established from PP from mice orally administered with high doses of BLG and was partially reversed by antibodies to TGF-beta. Intravenous transfer of OPP2 efficiently suppressed BLG-specific IgG1 production in serum following immunization, indicating the role of such T(reg) in the systemic tolerance after oral administration of antigen (oral tolerance). OPP clones secrete TGF-beta, IFN-gamma and low levels of IL-10, a cytokine pattern similar to that secreted by anergic T cells. OPP clones bear a CD4(+)CD25(+) phenotype and show significantly lower proliferative response compared to T(h)0 clones. This lower response is recovered by the addition of IL-2. Thus, antigen-specific CD4(+)CD25(+) T(reg), which have characteristics of anergic cells and actively suppress antibody production are induced in PP upon oral administration of protein antigen.

'Dressed for success' C-type lectin receptors for the delivery of glyco-vaccines to dendritic cells.

PubMed

Unger, Wendy W J; van Kooyk, Yvette

2011-02-01

Current strategies in immunotherapy for the treatment of tumors or autoimmunity focus on direct in vivo targeting of antigens to dendritic cells (DC), as these cells are the key regulators of immune responses. Multiple DC subsets can be distinguished in both humans and mice, based on phenotype and location. Moreover, recent data show that these subsets have distinct functions. All these features have implications for the design of DC-targeting vaccines. In this review we integrate recent knowledge on the different DC subsets in human and mice and how DC-expressed C-type lectin receptors (CLR) can be exploited for the induction of either antigen-specific immunity or tolerance. Copyright © 2010 Elsevier Ltd. All rights reserved.

Patient quality of life following induction of oral immunotherapy for food allergy.

PubMed

Epstein Rigbi, Na'ama; Katz, Yitzhak; Goldberg, Michael R; Levy, Michael B; Nachshon, Liat; Elizur, Arnon

2016-05-01

Patient quality of life improves following successful completion of oral immunotherapy (OIT), but the process itself might have undesirable effects. We aimed to evaluate patient quality of life following OIT initial induction. The Hebrew version of the Food Allergy Quality of Life Questionnaire-Parental Form (FAQLQ-PF) was validated and administered to the parents of children following the first week of OIT for food allergy (n = 119). Patient demographics and clinical history as well as the course of initial induction week were reviewed. Pre-OIT severity of food allergy, defined as severity of reactions due to accidental exposure to the allergenic food (anaphylactic reactions, p = 0.017; epinephrine use, p = 0.049; emergency room referrals p = 0.003; and hospital admissions, p = 0.015) and a lower number of tolerated doses during initial induction, reflective of a lower maximal tolerated dose for the different allergens (p = 0.011) were associated with worse total FAQLQ-PF scores. The number of tolerated doses during induction and pre-OIT emergency room referrals remained significantly associated with worse total score of the FAQLQ-PF on multivariate analysis (p = 0.016 and p = 0.005, respectively). The correlation between the number of tolerated doses and quality of life scores was moderate-strong primarily in children aged 6-12 years (Total score, r = -0.41, p = 0.001; Emotional Impact r = -0.42, p = 0.001; Food Anxiety, r = -0.38, p = 0.002; Social and Dietary Limitations, r = -0.33, p = 0.009). Pre-OIT reaction severity affects quality of life in both preschool and school-aged food-allergic children. In contrast, a lower maximal tolerated dose during OIT induction is associated with worse indices of quality of life primarily in children aged 6-12 years. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Novel Model on DST-Induced Transplantation Tolerance by the Transfer of Self-Specific Donor tTregs to a Haplotype-Matched Organ Recipient

PubMed Central

Mohr Gregoriussen, Angelica Maria; Bohr, Henrik Georg

2017-01-01

Donor-specific blood transfusion (DST) can lead to significant prolongation of allograft survival in experimental animal models and sometimes human recipients of solid organs. The mechanisms responsible for the beneficial effect on graft survival have been a topic of research and debate for decades and are not yet fully elucidated. Once we discover how the details of the mechanisms involved are linked, we could be within reach of a procedure making it possible to establish donor-specific tolerance with minimal or no immunosuppressive medication. Today, it is well established that CD4+Foxp3+ regulatory T cells (Tregs) are indispensable for maintaining immunological self-tolerance. A large number of animal studies have also shown that Tregs are essential for establishing and maintaining transplantation tolerance. In this paper, we present a hypothesis of one H2-haplotype-matched DST-induced transplantation tolerance (in mice). The formulated hypothesis is based on a re-interpretation of data from an immunogenetic experiment published by Niimi and colleagues in 2000. It is of importance that the naïve recipient mice in this study were never immunosuppressed and were therefore fully immune competent during the course of tolerance induction. Based on the immunological status of the recipients, we suggest that one H2-haplotype-matched self-specific Tregs derived from the transfusion blood can be activated and multiply in the host by binding to antigen-presenting cells presenting allopeptides in their major histocompatibility complex (MHC) class II (MHC-II). We also suggest that the endothelial and epithelial cells within the solid organ allograft upregulate the expression of MHC-II and attract the expanded Treg population to suppress inflammation within the graft. We further suggest that this biological process, here termed MHC-II recruitment, is a vital survival mechanism for organs (or the organism in general) when attacked by an immune system. PMID:28270810

Metronomic chemotherapy prevents therapy-induced stromal activation and induction of tumor-initiating cells

PubMed Central

Chan, Tze-Sian; Pai, Vincent C.; Tan, Kok-Tong; Yen, Chia-Jui; Hsu, Shu-Ching; Chen, Wei-Yu; Shan, Yan-Shen; Lee, Michael T.; Chu, Jui-Mei

2016-01-01

Although traditional chemotherapy kills a fraction of tumor cells, it also activates the stroma and can promote the growth and survival of residual cancer cells to foster tumor recurrence and metastasis. Accordingly, overcoming the host response induced by chemotherapy could substantially improve therapeutic outcome and patient survival. In this study, resistance to treatment and metastasis has been attributed to expansion of stem-like tumor-initiating cells (TICs). Molecular analysis of the tumor stroma in neoadjuvant chemotherapy–treated human desmoplastic cancers and orthotopic tumor xenografts revealed that traditional maximum-tolerated dose chemotherapy, regardless of the agents used, induces persistent STAT-1 and NF-κB activity in carcinoma-associated fibroblasts. This induction results in the expression and secretion of ELR motif–positive (ELR+) chemokines, which signal through CXCR-2 on carcinoma cells to trigger their phenotypic conversion into TICs and promote their invasive behaviors, leading to paradoxical tumor aggression after therapy. In contrast, the same overall dose administered as a low-dose metronomic chemotherapy regimen largely prevented therapy-induced stromal ELR+ chemokine paracrine signaling, thus enhancing treatment response and extending survival of mice carrying desmoplastic cancers. These experiments illustrate the importance of stroma in cancer therapy and how its impact on treatment resistance could be tempered by altering the dosing schedule of systemic chemotherapy. PMID:27881732

Diet and the anti-inflammatory effect of heat shock proteins.

PubMed

van Eden, Willem

2015-01-01

Stress proteins or heat shock proteins (HSPs) have a critical role in gut health and immune regulation. They have a functional significance as molecular chaperones for cell skeleton proteins and intercellular tight junction proteins. Herewith HSPs ensure gut epithelium integrity and effective intestinal barrier function. In addition, stress protein molecules such as HSP70 are a target for anti-inflammatory regulatory T cells (Tregs). Inflamed sites in the body feature inflammatory-stress induced enhanced levels of HSPs, which enable the immune system to target Tregs selectively to sites of inflammation. We have shown in experimental models of inflammatory diseases that both microbial HSP and endogenous (self) HSP molecules are capable of inducing the expansion of disease suppressive Tregs. Since the gut associated lymphoid tissue (GALT) is well poised towards the induction of regulation and tolerance, we set out to promote HSP expression and induction of Tregs in the gut lymphoid tissues by the oral administration of HSP co-inducing compounds. For the identification, selection and characterization of such compounds we have developed assay systems, such as reporter cell-lines, HSP specific T cell hybridomas and a transgenic mouse model (expression a HSP specific T cell receptor). The introduction of HSP coinducers into the diet constitutes a novel food based preventive or possibly even therapeutic approach in inflammatory diseases.

Tolerance to Vascularized Composite Allografts in Canine Mixed Hematopoietic Chimeras

PubMed Central

Mathes, David W.; Hwang, Billanna; Graves, Scott S.; Edwards, James; Chang, Jeff; Storer, Barry E.; Butts-Miwongtum, Tiffany; Sale, George E.; Nash, Richard A.; Storb, Rainer.

2012-01-01

Background Mixed donor-host chimerism, established through hematopoietic cell transplantation (HCT), is a highly reproducible strategy for the induction of tolerance towards solid organs. Here, we ask whether a nonmyeloablative conditioning regimen establishing mixed donor-host chimerism leads to tolerance of highly antigenic vascularized composite allografts. Methods Stable mixed chimerism was established in dogs given a sublethal dose (1–2 Gy) total body irradiation before and a short course of immunosuppression after dog leukocyte antigen-identical marrow transplantation. Vascularized composite allografts from marrow donors were performed after a median of 36 (range 4-54) months after HCT. Results All marrow recipients maintained mixed donor-host hematopoietic chimerism and accepted composite tissue grafts for periods ranging between 52 and 90 weeks; in turn, marrow donors rejected vascularized composite allografts from their respective marrow recipients within 18–29 days. Biopsies of muscle and skin of vascularized composite allografts from mixed chimeras showed few infiltrating cells compared to extensive infiltrates in biopsies of vascularized composite allografts from marrow donors. Elevated levels of CD3+ FoxP3+ T-regulatory cells were found in skin and muscle of vascularized composite allografts of mixed chimeras compared to normal tissues. In mixed chimeras, increased numbers of T-regulatory cells were found in draining compared to non-draining lymph nodes of vascularized composite allografts. Conclusion These data suggest that nonmyeloablative HCT may form the basis for future clinical applications of solid organ transplantation and that T-regulatory cells may function towards maintenance of the vascularized composite allograft. PMID:22082819

Regulatory Dendritic Cells.

PubMed

Sato, Katsuaki; Uto, Tomofumi; Fukaya, Tomohiro; Takagi, Hideaki

2017-01-01

Dendritic cells (DCs) comprise heterogeneous subsets, functionally classified into conventional DCs (cDCs) and plasmacytoid DCs (pDCs). DCs are considered to be essential antigen (Ag)-presenting cells (APCs) that play crucial roles in activation and fine-tuning of innate and adaptive immunity under inflammatory conditions, as well as induction of immune tolerance to maintain immune homeostasis under steady-state conditions. Furthermore, DC functions can be modified and influenced by stimulation with various extrinsic factors, such as ligands for pattern-recognition receptors (PRRs) and cytokines. On the other hand, treatment of DCs with certain immunosuppressive drugs and molecules leads to the generation of tolerogenic DCs that show downregulation of both the major histocompatibility complex (MHC) and costimulatory molecules, and not only show defective T-cell activation, but also possess tolerogenic properties including the induction of anergic T-cells and regulatory T (T reg ) cells. To develop an effective strategy for Ag-specific intervention of T-cell-mediated immune disorders, we have previously established the modified DCs with moderately high levels of MHC molecules that are defective in the expression of costimulatory molecules that had a greater immunoregulatory property than classical tolerogenic DCs, which we therefore designated as regulatory DCs (DC reg ). Herein, we integrate the current understanding of the role of DCs in the control of immune responses, and further provide new information of the characteristics of tolerogenic DCs and DC reg , as well as their regulation of immune responses and disorders.

The nitric oxide donor JS-K sensitizes U87 glioma cells to repetitive irradiation.

PubMed

Heckler, Max; Osterberg, Nadja; Guenzle, Jessica; Thiede-Stan, Nina Kristin; Reichardt, Wilfried; Weidensteiner, Claudia; Saavedra, Joseph E; Weyerbrock, Astrid

2017-06-01

As a potent radiosensitizer nitric oxide (NO) may be a putative adjuvant in the treatment of malignant gliomas which are known for their radio- and chemoresistance. The NO donor prodrug JS-K (O2-(2.4-dinitrophenyl) 1-[(4-ethoxycarbonyl) piperazin-1-yl] diazen-1-ium-1,2-diolate) allows cell-type specific intracellular NO release via enzymatic activation by glutathione-S-transferases overexpressed in glioblastoma multiforme. The cytotoxic and radiosensitizing efficacy of JS-K was assessed in U87 glioma cells in vitro focusing on cell proliferation, induction of DNA damage, and cell death. In vivo efficacy of JS-K and repetitive irradiation were investigated in an orthotopic U87 xenograft model in mice. For the first time, we could show that JS-K acts as a potent cytotoxic and radiosensitizing agent in U87 cells in vitro. This dose- and time-dependent effect is due to an enhanced induction of DNA double-strand breaks leading to mitotic catastrophe as the dominant form of cell death. However, this potent cytotoxic and radiosensitizing effect could not be confirmed in an intracranial U87 xenograft model, possibly due to insufficient delivery into the brain. Although NO donor treatment was well tolerated, neither a retardation of tumor growth nor an extended survival could be observed after JS-K and/or radiotherapy.

Induction of allograft tolerance through costimulatory blockade: first selection of drugs in vitro.

PubMed

Vierboom, Michel P M; Ossevoort, Miriam; Sick, Ella A; Haanstra, Krista; Jonker, Margreet

2003-01-01

The development of an in vitro assay predicting the chances of graft survival after treatment with immunoregulatory agents is a major topic in transplantation. Antibodies (Abs) interfering in the costimulatory pathway are promising candidates for the induction of tolerance. To evaluate these antibodies for clinical use studies non-human primates are the only feasible option due to species specificity of the antibodies. Peripheral blood mononuclear cells, isolated from a large panel of rhesus monkeys, were used in a unidirectional mixed lymphocyte reaction to evaluate the ability of antibodies blocking the costimulatory pathway, to affect both primary and secondary proliferative and cytolytic allospecific immune responses in vitro. These blocking antibodies were also used in protocols prolonging allograft survival in a life-supporting kidney allotransplant model in rhesus macaques. The ultimate aim is to establish a correlation between parameters obtained in vitro and the success of transplantation in vivo. The combination of anti-CD80 and anti-CD86 resulted in a complete abrogation of the primary alloresponse as measured in a proliferation assay. Adding anti-CD40 significantly reduced this inhibitory effect although the in vivo effects of this antibody have been shown to be beneficial. The secondary response was most prominently inhibited by the combination of anti-CD80/86. Paradoxically, anti-CD40 alone markedly inhibited the secondary proliferative response, but did not add to the inhibitory effect of the combination of anti-CD80/86. The cytolytic response was inhibited maximally only when CsA was added to the combination of anti-CD80/86. Treatment with monoclonal antibodies alone without immunosuppressive drugs was sufficient to maintain graft survival during the time of treatment in most animals. However, rejection was initiated as soon as the treatment ceased and no tolerance, resulting in long-term graft and patient survival, was established. The complete inhibition of primary alloresponses and the partial inhibition of secondary proliferative alloresponses correlate with prolonged graft survival during treatment, but have no predictive value for the success of tolerance induction for kidney allografts in rhesus monkeys.

Fault tolerant vector control of induction motor drive

NASA Astrophysics Data System (ADS)

Odnokopylov, G.; Bragin, A.

2014-10-01

For electric composed of technical objects hazardous industries, such as nuclear, military, chemical, etc. an urgent task is to increase their resiliency and survivability. The construction principle of vector control system fault-tolerant asynchronous electric. Displaying recovery efficiency three-phase induction motor drive in emergency mode using two-phase vector control system. The process of formation of a simulation model of the asynchronous electric unbalance in emergency mode. When modeling used coordinate transformation, providing emergency operation electric unbalance work. The results of modeling transient phase loss motor stator. During a power failure phase induction motor cannot save circular rotating field in the air gap of the motor and ensure the restoration of its efficiency at rated torque and speed.

Depletion of CD52-positive cells inhibits the development of central nervous system autoimmune disease, but deletes an immune-tolerance promoting CD8 T-cell population. Implications for secondary autoimmunity of alemtuzumab in multiple sclerosis.

PubMed

von Kutzleben, Stephanie; Pryce, Gareth; Giovannoni, Gavin; Baker, David

2017-04-01

The objective was to determine whether CD52 lymphocyte depletion can act to promote immunological tolerance induction by way of intravenous antigen administration such that it could be used to either improve efficiency of multiple sclerosis (MS) inhibition or inhibit secondary autoimmunities that may occur following alemtuzumab use in MS. Relapsing experimental autoimmune encephalomyelitis was induced in ABH mice and immune cell depletion was therapeutically applied using mouse CD52 or CD4 (in conjunction with CD8 or CD20) depleting monoclonal antibodies. Immunological unresponsiveness was then subsequently induced using intravenous central nervous system antigens and responses were assessed clinically. A dose-response of CD4 monoclonal antibody depletion indicated that the 60-70% functional CD4 T-cell depletion achieved in perceived failed trials in MS was perhaps too low to even stop disease in animals. However, more marked (~75-90%) physical depletion of CD4 T cells by CD4 and CD52 depleting antibodies inhibited relapsing disease. Surprisingly, in contrast to CD4 depletion, CD52 depletion blocked robust immunological unresponsiveness through a mechanism involving CD8 T cells. Although efficacy was related to the level of CD4 T-cell depletion, the observations that CD52 depletion of CD19 B cells was less marked in lymphoid organs than in the blood provides a rationale for the rapid B-cell hyper-repopulation that occurs following alemtuzumab administration in MS. That B cells repopulate in the relative absence of T-cell regulatory mechanisms that promote immune tolerance may account for the secondary B-cell autoimmunities, which occur following alemtuzumab treatment of MS. © 2016 The Authors. Immunology Published by John Wiley & Sons Ltd.

Induction and concurrent chemotherapy with high-dose thoracic conformal radiation therapy in unresectable stage IIIA and IIIB non-small-cell lung cancer: a dose-escalation phase I trial.

PubMed

Socinski, Mark A; Morris, David E; Halle, Jan S; Moore, Dominic T; Hensing, Thomas A; Limentani, Steven A; Fraser, Robert; Tynan, Maureen; Mears, Andrea; Rivera, M Patricia; Detterbeck, Frank C; Rosenman, Julian G

2004-11-01

Local control rates at conventional radiotherapy doses (60 to 66 Gy) are poor in stage III non-small-cell lung cancer (NSCLC). Dose escalation using three-dimensional thoracic conformal radiation therapy (TCRT) is one strategy to improve local control and perhaps survival. Stage III NSCLC patients with a good performance status (PS) were treated with induction chemotherapy (carboplatin area under the curve [AUC] 5, irinotecan 100 mg/m(2), and paclitaxel 175 mg/m(2) days 1 and 22) followed by concurrent chemotherapy (carboplatin AUC 2 and paclitaxel 45 mg/m(2) weekly for 7 to 8 weeks) beginning on day 43. Pre- and postchemotherapy computed tomography scans defined the initial clinical target volume (CTV(I)) and boost clinical target volume (CTV(B)), respectively. The CTV(I) received 40 to 50 Gy; the CTV(B) received escalating doses of TCRT from 78 Gy to 82, 86, and 90 Gy. The primary objective was to escalate the TCRT dose from 78 to 90 Gy or to the maximum-tolerated dose. Twenty-nine patients were enrolled (25 assessable patients; median age, 59 years; 62% male; 45% stage IIIA; 38% PS 0; and 38% > or = 5% weight loss). Induction CIP was well tolerated (with filgrastim support) and active (partial response rate, 46.2%; stable disease, 53.8%; and early progression, 0%). The TCRT dose was escalated from 78 to 90 Gy without dose-limiting toxicity. The primary acute toxicity was esophagitis (16%, all grade 3). Late toxicity consisted of grade 2 esophageal stricture (n = 3), bronchial stenosis (n = 2), and fatal hemoptysis (n = 2). The overall response rate was 60%, with a median survival time and 1-year survival probability of 24 months and 0.73 (95% CI, 0.55 to 0.89), respectively. CONCLUSION Escalation of the TCRT dose from 78 to 90 Gy in the context of induction and concurrent chemotherapy was accomplished safely in stage III NSCLC patients.

Alternative forms of lethality in mitomycin C-induced bacteria carrying ColE1 plasmids

PubMed Central

Suit, Joan L.; Fan, M.-L. Judy; Sabik, Joseph F.; Labarre, Robert; Luria, S. E.

1983-01-01

We have studied the physiological effects of mitomycin C induction on cells carrying ColE1 plasmids with differing configurations of three genes: the structural gene coding for colicin (cea), a gene responsible for mitomycin C lethality (kil) that we located as part of an operon with cea, and the immunity (imm) gene, which lies near cea but is not in the same operon. kil is close to or overlaps imm. When cea+ plasmids are present mitomycin C induction results in 100-fold or greater increases in the level of colicin. Within an hour after induction more than 90% of cells carrying cea+kil+ plasmids are killed and macromolecular synthesis stops, capacity for transport of proline, thiomethyl β-D-galactoside, and α-methyl glucoside is lost, and the membrane becomes abnormally permeable as indicated by an increased accessibility of intracellular β-galactosidase to the substrate o-nitrophenyl β-D-galactoside. All of these events occur when a cea-kil+imm+ plasmid is present and none does when the plasmid is cea+kil-imm+, so the damage can be attributed solely to the Kil function and not to the presence of colicin. However, cells carrying a cea+kil-imm- plasmid are killed upon induction, apparently by action of endogenous colicin on the nonimmune cytoplasmic membrane. The pattern of accompanying physiological damage is distinguished from the kil+-associated damage by an enhancement of α-methyl glucoside uptake and accumulation and efflux of α-methyl glucoside 6-phosphate and by an absence of the alteration in membrane permeability for o-nitrophenyl β-D-galactoside. These features are typical of colicin E1 action on the membrane. The induced damage is not prevented by trypsin and occurs in cells of a strain specifically tolerant to exogenous colicin E1, indicating that the attack is from inside the cell. PMID:6403939

Myf5 and Myogenin in the development of thymic myoid cells - Implications for a murine in vivo model of myasthenia gravis.

PubMed

Hu, Bo; Simon-Keller, Katja; Küffer, Stefan; Ströbel, Philipp; Braun, Thomas; Marx, Alexander; Porubsky, Stefan

2016-03-01

Myasthenia gravis (MG) is caused by autoantibodies against the neuromuscular junction of striated muscle. Most MG patients have autoreactive T- and B-cells directed to the acetylcholine receptor (AChR). To achieve immunologic tolerance, developing thymocytes are normally eliminated after recognition of self-antigen-derived peptides. Presentation of muscle-specific antigens is likely achieved through two pathways: on medullary thymic epithelial cells and on medullary dendritic cells cross-presenting peptides derived from a unique population of thymic myoid cells (TMC). Decades ago, it has been hypothesized that TMC play a key role in the induction of immunological tolerance towards skeletal muscle antigens. However, an experimental model to address this postulate has not been available. To generate such a model, we tested the hypothesis that the development of TMC depends on myogenic regulatory factors. To this end, we utilized Myf5-deficient mice, which lack the first wave of muscle cells but form normal skeletal muscles later during development, and Myogenin-deficient mice, which fail to form differentiated myofibers. We demonstrate for the first time that Myf5- and Myogenin-deficient mice showed a partial or complete, respectively, loss of TMC in an otherwise regularly structured thymus. To overcome early postnatal lethality of muscle-deficient, Myogenin-knockout mice we transplanted Myogenin-deficient fetal thymuses into Foxn1(nu/nu) mice that lack their own thymus anlage. We found that the transplants are functional but lack TMC. In combination with established immunization strategies (utilizing AChR or Titin), this model should enable us in the future testing the hypothesis that TMC play an indispensable role in the development of central tolerance towards striated muscle antigens. Copyright © 2015 Elsevier Inc. All rights reserved.

Kinetic characteristics of euflammation: the induction of controlled inflammation without overt sickness behavior.

PubMed

Tarr, Andrew J; Liu, Xiaoyu; Reed, Nathaniel S; Quan, Ning

2014-11-01

We found recently that controlled progressive challenge with subthreshold levels of E. coli can confer progressively stronger resistance to future reinfection-induced sickness behavior to the host. We have termed this type of inflammation "euflammation". In this study, we further characterized the kinetic changes in the behavior, immunological, and neuroendocrine aspects of euflammation. Results show euflammatory animals only display transient and subtle sickness behaviors of anorexia, adipsia, and anhedonia upon a later infectious challenge which would have caused much more severe and longer lasting sickness behavior if given without prior euflammatory challenges. Similarly, infectious challenge-induced corticosterone secretion was greatly ameliorated in euflammatory animals. At the site of E.coli priming injections, which we termed euflammation induction locus (EIL), innate immune cells displayed a partial endotoxin tolerant phenotype with reduced expression of innate activation markers and muted inflammatory cytokine expression upon ex vivo LPS stimulation, whereas innate immune cells outside EIL displayed largely opposite characteristics. Bacterial clearance function, however, was enhanced both inside and outside EIL. Finally, sickness induction by an infectious challenge placed outside the EIL was also abrogated. These results suggest euflammation could be used as an efficient method to "train" the innate immune system to resist the consequences of future infectious/inflammatory challenges. Copyright © 2014 Elsevier Inc. All rights reserved.

PPAR-γ contributes to immunity by cancer vaccines that secrete GM-CSF.

PubMed

Goyal, Girija; Wong, Karrie; Nirschl, Christopher J; Souders, Nicholas; Neuberg, Donna; Anandasabapathy, Niroshana; Dranoff, Glenn

2018-04-18

Peroxisome proliferator activated receptor-γ (PPARγ) is a lipid-activated nuclear receptor that promotes immune tolerance through effects on macrophages, dendritic cells (DCs), and regulatory T cells (Tregs). Granulocyte-macrophage colony stimulating factor (GM-CSF) induces PPARγ expression in multiple myeloid cell types. GM-CSF contributes to both immune tolerance and protection, but the role of PPARγ in these pathways is poorly understood. Here we reveal an unexpected stimulatory role for PPARγ in the generation of antitumor immunity with irradiated, GM-CSF-secreting tumor-cell vaccines (GVAX). Mice harboring a deletion of PPARγ in lysozyme M (LysM)-expressing myeloid cells showed a decreased ratio of CD8+ T effectors to Tregs and impaired tumor rejection with GVAX. Diminished tumor protection was associated with altered dendritic cell responses and increased production of the Treg attracting chemokines CCL17 and CLL22. Correspondingly, the systemic administration of PPARγ agonists to vaccinated mice elevated the CD8+ T effector to Treg ratio through effects on myeloid cells and intensified the antitumor activity of GVAX combined with cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) antibody blockade. PPARγ agonists similarly attenuated Treg induction and decreased CCL17 and CCL22 levels in cultures of human peripheral blood mononuclear cells (PBMCs) with GM-CSF-secreting tumor cells. Together, these results highlight a key role for myeloid cell PPARγ in GM-CSF stimulated antitumor immunity and suggest that PPARγ agonists might be useful in cancer immunotherapy. Copyright ©2018, American Association for Cancer Research.

Kidney Versus Islet Allograft Survival After Induction of Mixed Chimerism With Combined Donor Bone Marrow Transplantation.

PubMed

Oura, Tetsu; Ko, Dicken S C; Boskovic, Svjetlan; O'Neil, John J; Chipashvili, Vaja; Koulmanda, Maria; Hotta, Kiyohiko; Kawai, Kento; Nadazdin, Ognjenka; Smith, R Neal; Cosimi, A B; Kawai, Tatsuo

2016-01-01

We have previously reported successful induction of transient mixed chimerism and long-term acceptance of renal allografts in MHC mismatched nonhuman primates. In this study, we attempted to extend this tolerance induction approach to islet allografts. A total of eight recipients underwent MHC mismatched combined islet and bone marrow (BM) transplantation after induction of diabetes by streptozotocin. Three recipients were treated after a nonmyeloablative conditioning regimen that included low-dose total body and thymic irradiation, horse Atgam (ATG), six doses of anti-CD154 monoclonal antibody (mAb), and a 1-month course of cyclosporine (CyA) (Islet A). In Islet B, anti-CD8 mAb was administered in place of CyA. In Islet C, two recipients were treated with Islet B, but without ATG. The results were compared with previously reported results of eight cynomolgus monkeys that received combined kidney and BM transplantation (Kidney A) following the same conditioning regimen used in Islet A. The majority of kidney/BM recipients achieved long-term renal allograft survival after induction of transient chimerism. However, prolonged islet survival was not achieved in similarly conditioned islet/BM recipients (Islet A), despite induction of comparable levels of chimerism. In order to rule out islet allograft loss due to CyA toxicity, three recipients were treated with anti-CD8 mAb in place of CyA. Although these recipients developed significantly superior mixed chimerism and more prolonged islet allograft survival (61, 103, and 113 days), islet function was lost soon after the disappearance of chimerism. In Islet C recipients, neither prolonged chimerism nor islet survival was observed (30 and 40 days). Significant improvement of mixed chimerism induction and islet allograft survival were achieved with a CyA-free regimen that included anti-CD8 mAb. However, unlike the kidney allograft, islet allograft tolerance was not induced with transient chimerism. Induction of more durable mixed chimerism may be necessary for induction of islet allograft tolerance.

Indoleamine 2,3-dioxygenase-dependent tryptophan metabolites contribute to tolerance induction during allergen immunotherapy in a mouse model.

PubMed

Taher, Yousef A; Piavaux, Benoit J A; Gras, Reneé; van Esch, Betty C A M; Hofman, Gerard A; Bloksma, Nanne; Henricks, Paul A J; van Oosterhout, Antoon J M

2008-04-01

The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) has been implicated in immune suppression and tolerance induction. We examined (1) whether IDO activity is required during tolerance induction by allergen immunotherapy or for the subsequent suppressive effects on asthma manifestations and (2) whether tryptophan depletion or generation of its downstream metabolites is involved. Ovalbumin (OVA)-sensitized and OVA-challenged BALB/c mice that display increased airway responsiveness to methacholine, serum OVA-specific IgE levels, bronchoalveolar eosinophilia, and TH2 cytokine levels were used as a model of allergic asthma. Sensitized mice received subcutaneous optimal (1 mg) or suboptimal (100 microg) OVA immunotherapy. Inhibition of IDO by 1-methyl-DL-tryptophan during immunotherapy, but not during inhalation challenge, partially reversed the suppressive effects of immunotherapy on airway eosinophilia and TH2 cytokine levels, whereas airway hyperresponsiveness and serum OVA-specific IgE levels remained suppressed. Administration of tryptophan during immunotherapy failed to abrogate its beneficial effects toward allergic airway inflammation. Interestingly, administration of tryptophan or its metabolites, kynurenine, 3-hydroxykynurenine, and xanthurenic acid, but not 3-hydroxyanthranilinic acid, quinolinic acid, and kynurenic acid, during suboptimal immunotherapy potentiated the reduction of eosinophilia. These effects coincided with reduced TH2 cytokine levels in bronchoalveolar lavage fluid, but no effects on IgE levels were detected. During immunotherapy, the tryptophan metabolites kynurenine, 3-hydroxykynurenine, and xanthurenic acid generated through IDO contribute to tolerance induction regarding TH2-dependent allergic airway inflammation.

The Saccharomyces cerevisiae RAD9, RAD17, RAD24 and MEC3 genes are required for tolerating irreparable, ultraviolet-induced DNA damage.

PubMed Central

Paulovich, A G; Armour, C D; Hartwell, L H

1998-01-01

In wild-type Saccharomyces cerevisiae, a checkpoint slows the rate of progression of an ongoing S phase in response to exposure to a DNA-alkylating agent. Mutations that eliminate S phase regulation also confer sensitivity to alkylating agents, leading us to suggest that, by regulating the S phase rate, cells are either better able to repair or better able to replicate damaged DNA. In this study, we determine the effects of mutations that impair S phase regulation on the ability of excision repair-defective cells to replicate irreparably UV-damaged DNA. We assay survival after UV irradiation, as well as the genetic consequences of replicating a damaged template, namely mutation and sister chromatid exchange induction. We find that RAD9, RAD17, RAD24, and MEC3 are required for UV-induced (although not spontaneous) mutagenesis, and that RAD9 and RAD17 (but not REV3, RAD24, and MEC3) are required for maximal induction of replication-dependent sister chromatid exchange. Therefore, checkpoint genes not only control cell cycle progression in response to damage, but also play a role in accommodating DNA damage during replication. PMID:9725831

The Saccharomyces cerevisiae RAD9, RAD17, RAD24 and MEC3 genes are required for tolerating irreparable, ultraviolet-induced DNA damage.

PubMed

Paulovich, A G; Armour, C D; Hartwell, L H

1998-09-01

In wild-type Saccharomyces cerevisiae, a checkpoint slows the rate of progression of an ongoing S phase in response to exposure to a DNA-alkylating agent. Mutations that eliminate S phase regulation also confer sensitivity to alkylating agents, leading us to suggest that, by regulating the S phase rate, cells are either better able to repair or better able to replicate damaged DNA. In this study, we determine the effects of mutations that impair S phase regulation on the ability of excision repair-defective cells to replicate irreparably UV-damaged DNA. We assay survival after UV irradiation, as well as the genetic consequences of replicating a damaged template, namely mutation and sister chromatid exchange induction. We find that RAD9, RAD17, RAD24, and MEC3 are required for UV-induced (although not spontaneous) mutagenesis, and that RAD9 and RAD17 (but not REV3, RAD24, and MEC3) are required for maximal induction of replication-dependent sister chromatid exchange. Therefore, checkpoint genes not only control cell cycle progression in response to damage, but also play a role in accommodating DNA damage during replication.

iTRAQ-based proteomic analysis reveals the mechanisms of silicon-mediated cadmium tolerance in rice (Oryza sativa) cells.

PubMed

Ma, Jie; Sheng, Huachun; Li, Xiuli; Wang, Lijun

2016-07-01

Silicon (Si) can alleviate cadmium (Cd) stress in rice (Oryza sativa) plants, however, the understanding of the molecular mechanisms at the single-cell level remains limited. To address these questions, we investigated suspension cells of rice cultured in the dark environment in the absence and presence of Si with either short- (12 h) or long-term (5 d) Cd treatments using a combination of isobaric tags for relative and absolute quantitation (iTRAQ), fluorescent staining, and inductively coupled plasma mass spectroscopy (ICP-MS). We identified 100 proteins differentially regulated by Si under the short- or long-term Cd stress. 70% of these proteins were down-regulated, suggesting that Si may improve protein use efficiency by maintaining cells in the normal physiological status. Furthermore, we showed two different mechanisms for Si-mediated Cd tolerance. Under the short-term Cd stress, the Si-modified cell walls inhibited the uptake of Cd ions into cells and consequently reduced the expressions of glycosidase, cell surface non-specific lipid-transfer proteins (nsLTPs), and several stress-related proteins. Under the long-term Cd stress, the amount of Cd in the cytoplasm in Si-accumulating (+Si) cells was decreased by compartmentation of Cd into vacuoles, thus leading to a lower expression of glutathione S-transferases (GST). These results provide protein-level insights into the Si-mediated Cd detoxification in rice single cells. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Successful pod infections by Moniliophthora roreri result in differential Theobroma cacao gene expression depending on the clone's level of tolerance.

PubMed

Ali, Shahin S; Melnick, Rachel L; Crozier, Jayne; Phillips-Mora, Wilberth; Strem, Mary D; Shao, Jonathan; Zhang, Dapeng; Sicher, Richard; Meinhardt, Lyndel; Bailey, Bryan A

2014-09-01

An understanding of the tolerance mechanisms of Theobroma cacao used against Moniliophthora roreri, the causal agent of frosty pod rot, is important for the generation of stable disease-tolerant clones. A comparative view was obtained of transcript populations of infected pods from two susceptible and two tolerant clones using RNA sequence (RNA-Seq) analysis. A total of 3009 transcripts showed differential expression among clones. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis of differentially expressed genes indicated shifts in 152 different metabolic pathways between the tolerant and susceptible clones. Real-time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR) analyses of 36 genes verified the differential expression. Regression analysis validated a uniform progression in gene expression in association with infection levels and fungal loads in the susceptible clones. Expression patterns observed in the susceptible clones diverged in tolerant clones, with many genes showing higher expression at a low level of infection and fungal load. Principal coordinate analyses of real-time qRT-PCR data separated the gene expression patterns between susceptible and tolerant clones for pods showing malformation. Although some genes were constitutively differentially expressed between clones, most results suggested that defence responses were induced at low fungal load in the tolerant clones. Several elicitor-responsive genes were highly expressed in tolerant clones, suggesting rapid recognition of the pathogen and induction of defence genes. Expression patterns suggested that the jasmonic acid-ethylene- and/or salicylic acid-mediated defence pathways were activated in the tolerant clones, being enhanced by reduced brassinosteroid (BR) biosynthesis and catabolic inactivation of both BR and abscisic acids. Finally, several genes associated with hypersensitive response-like cell death were also induced in tolerant clones. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Liver Immunology

PubMed Central

Bogdanos, Dimitrios P.; Gao, Bin; Gershwin, M. Eric

2014-01-01

The liver is the largest organ in the body and is generally regarded by non-immunologists as not having lymphoid function. However, such is far from accurate. This review highlights the importance of the liver as a lymphoid organ. Firstly, we discuss experimental data surrounding the role of liver as a lymphoid organ. The liver facilitates a tolerance rather than immunoreactivity, which protects the host from antigenic overload of dietary components and drugs derived from the gut and is also instrumental to fetal immune tolerance. Loss of liver tolerance leads to autoaggressive phenomena which if are not controlled by regulatory lymphoid populations may lead to the induction of autoimmune liver diseases. Liver-related lymphoid subpopulations also act as critical antigen-presenting cells. The study of the immunological properties of liver and delineation of the microenvironment of the intrahepatic milieu in normal and diseased livers provides a platform to understand the hierarchy of a series of detrimental events which lead to immune-mediated destruction of the liver and the rejection of liver allografts. The majority of emphasis within this review will be on the normal mononuclear cell composition of the liver. However, within this context, we will discus select, but not all, immune mediated liver disease and attempt to place these data in the context of human autoimmunity. PMID:23720323

Immunomodulatory Effects of Mixed Hematopoietic Chimerism: Immune Tolerance in Canine Model of Lung Transplantation

PubMed Central

Nash;, Richard A.; Yunosov;, Murad; Abrams;, Kraig; Hwang;, Billanna; Castilla-Llorente;, Cristina; Chen;, Peter; Farivar;, Alexander S.; Georges;, George E.; Hackman;, Robert C.; Lamm;, Wayne J.E.; Lesnikova;, Marina; Ochs;, Hans D.; Randolph-Habecker;, Julie; Ziegler;, Stephen F.; Storb;, Rainer; Storer;, Barry; Madtes;, David K.; Glenny;, Robb; Mulligan, Michael S.

2010-01-01

Long-term survival after lung transplantation is limited by acute and chronic graft rejection. Induction of immune tolerance by first establishing mixed hematopoietic chimerism (MC) is a promising strategy to improve outcomes. In a preclinical canine model, stable MC was established in recipients after reduced-intensity conditioning and hematopoietic cell transplantation from a DLA-identical donor. Delayed lung transplantation was performed from the stem cell donor without pharmacological immunosuppression. Lung graft survival without loss of function was prolonged in chimeric (n=5) vs. nonchimeric (n=7) recipients (p≤0.05, Fisher’s test). There were histological changes consistent with low grade rejection in 3/5 of the lung grafts in chimeric recipients at ≥1 year. Chimeric recipients after lung transplantation had a normal immune response to a T-dependent antigen. Compared to normal dogs, there were significant increases of CD4+INFγ+, CD4+IL-4+ and CD8+ INFγ+ T-cell subsets in the blood (p <0.0001 for each of the 3 T-cell subsets). Markers for regulatory T-cell subsets including foxP3, IL10 and TGFβ were also increased in CD3+ T cells from the blood and peripheral tissues of chimeric recipients after lung transplantation. Establishing MC is immunomodulatory and observed changes were consistent with activation of both the effector and regulatory immune response. PMID:19422333

Antibody-Antigen-Adjuvant Conjugates Enable Co-Delivery of Antigen and Adjuvant to Dendritic Cells in Cis but Only Have Partial Targeting Specificity

PubMed Central

Abuknesha, Ram; Uematsu, Satoshi; Akira, Shizuo; Nestle, Frank O.; Diebold, Sandra S.

2012-01-01

Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC) that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA) and CpG oligodeoxynucleotides (ODN). We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL) responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses. PMID:22808118

Chicken-Specific Kinome Array Reveals that Salmonella enterica Serovar Enteritidis Modulates Host Immune Signaling Pathways in the Cecum to Establish a Persistence Infection

PubMed Central

Kogut, Michael H.; Swaggerty, Christina L.; Byrd, James Allen; Selvaraj, Ramesh; Arsenault, Ryan J.

2016-01-01

Non-typhoidal Salmonella enterica induces an early, short-lived pro-inflammatory response in chickens that is asymptomatic of clinical disease and results in a persistent colonization of the gastrointestinal (GI) tract that transmits infections to naïve hosts via fecal shedding of bacteria. The underlying mechanisms that control this persistent colonization of the ceca of chickens by Salmonella are only beginning to be elucidated. We hypothesize that alteration of host signaling pathways mediate the induction of a tolerance response. Using chicken-specific kinomic immune peptide arrays and quantitative RT-PCR of infected cecal tissue, we have previously evaluated the development of disease tolerance in chickens infected with Salmonella enterica serovar Enteritidis (S. Enteritidis) in a persistent infection model (4–14 days post infection). Here, we have further outlined the induction of an tolerance defense strategy in the cecum of chickens infected with S. Enteritidis beginning around four days post-primary infection. The response is characterized by alterations in the activation of T cell signaling mediated by the dephosphorylation of phospholipase c-γ1 (PLCG1) that inhibits NF-κB signaling and activates nuclear factor of activated T-cells (NFAT) signaling and blockage of interferon-γ (IFN-γ) production through the disruption of the JAK-STAT signaling pathway (dephosphorylation of JAK2, JAK3, and STAT4). Further, we measured a significant down-regulation reduction in IFN-γ mRNA expression. These studies, combined with our previous findings, describe global phenotypic changes in the avian cecum of Salmonella Enteritidis-infected chickens that decreases the host responsiveness resulting in the establishment of persistent colonization. The identified tissue protein kinases also represent potential targets for future antimicrobial compounds for decreasing Salmonella loads in the intestines of food animals before going to market. PMID:27472318

Chicken-Specific Kinome Array Reveals that Salmonella enterica Serovar Enteritidis Modulates Host Immune Signaling Pathways in the Cecum to Establish a Persistence Infection.

PubMed

Kogut, Michael H; Swaggerty, Christina L; Byrd, James Allen; Selvaraj, Ramesh; Arsenault, Ryan J

2016-07-27

Non-typhoidal Salmonella enterica induces an early, short-lived pro-inflammatory response in chickens that is asymptomatic of clinical disease and results in a persistent colonization of the gastrointestinal (GI) tract that transmits infections to naïve hosts via fecal shedding of bacteria. The underlying mechanisms that control this persistent colonization of the ceca of chickens by Salmonella are only beginning to be elucidated. We hypothesize that alteration of host signaling pathways mediate the induction of a tolerance response. Using chicken-specific kinomic immune peptide arrays and quantitative RT-PCR of infected cecal tissue, we have previously evaluated the development of disease tolerance in chickens infected with Salmonella enterica serovar Enteritidis (S. Enteritidis) in a persistent infection model (4-14 days post infection). Here, we have further outlined the induction of an tolerance defense strategy in the cecum of chickens infected with S. Enteritidis beginning around four days post-primary infection. The response is characterized by alterations in the activation of T cell signaling mediated by the dephosphorylation of phospholipase c-γ1 (PLCG1) that inhibits NF-κB signaling and activates nuclear factor of activated T-cells (NFAT) signaling and blockage of interferon-γ (IFN-γ) production through the disruption of the JAK-STAT signaling pathway (dephosphorylation of JAK2, JAK3, and STAT4). Further, we measured a significant down-regulation reduction in IFN-γ mRNA expression. These studies, combined with our previous findings, describe global phenotypic changes in the avian cecum of Salmonella Enteritidis-infected chickens that decreases the host responsiveness resulting in the establishment of persistent colonization. The identified tissue protein kinases also represent potential targets for future antimicrobial compounds for decreasing Salmonella loads in the intestines of food animals before going to market.

c-MAF-dependent regulatory T cells mediate immunological tolerance to a gut pathobiont.

PubMed

Xu, Mo; Pokrovskii, Maria; Ding, Yi; Yi, Ren; Au, Christy; Harrison, Oliver J; Galan, Carolina; Belkaid, Yasmine; Bonneau, Richard; Littman, Dan R

2018-02-15

Both microbial and host genetic factors contribute to the pathogenesis of autoimmune diseases. There is accumulating evidence that microbial species that potentiate chronic inflammation, as in inflammatory bowel disease, often also colonize healthy individuals. These microorganisms, including the Helicobacter species, can induce pathogenic T cells and are collectively referred to as pathobionts. However, how such T cells are constrained in healthy individuals is not yet understood. Here we report that host tolerance to a potentially pathogenic bacterium, Helicobacter hepaticus, is mediated by the induction of RORγt + FOXP3 + regulatory T (iT reg ) cells that selectively restrain pro-inflammatory T helper 17 (T H 17) cells and whose function is dependent on the transcription factor c-MAF. Whereas colonization of wild-type mice by H. hepaticus promoted differentiation of RORγt-expressing microorganism-specific iT reg cells in the large intestine, in disease-susceptible IL-10-deficient mice, there was instead expansion of colitogenic T H 17 cells. Inactivation of c-MAF in the T reg cell compartment impaired differentiation and function, including IL-10 production, of bacteria-specific iT reg cells, and resulted in the accumulation of H. hepaticus-specific inflammatory T H 17 cells and spontaneous colitis. By contrast, RORγt inactivation in T reg cells had only a minor effect on the bacteria-specific T reg and T H 17 cell balance, and did not result in inflammation. Our results suggest that pathobiont-dependent inflammatory bowel disease is driven by microbiota-reactive T cells that have escaped this c-MAF-dependent mechanism of iT reg -T H 17 homeostasis.

Hepatocyte growth factor limits autoimmune neuroinflammation via glucocorticoid-induced leucine zipper expression in dendritic cells.

PubMed

Benkhoucha, Mahdia; Molnarfi, Nicolas; Dunand-Sauthier, Isabelle; Merkler, Doron; Schneiter, Gregory; Bruscoli, Stefano; Riccardi, Carlo; Tabata, Yasuhiko; Funakoshi, Hiroshi; Nakamura, Toshikazu; Reith, Walter; Santiago-Raber, Marie-Laure; Lalive, Patrice H

2014-09-15

Autoimmune neuroinflammation, including multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), a prototype for T cell-mediated autoimmunity, is believed to result from immune tolerance dysfunction leading to demyelination and substantial neurodegeneration. We previously showed that CNS-restricted expression of hepatocyte growth factor (HGF), a potent neuroprotective factor, reduced CNS inflammation and clinical deficits associated with EAE. In this study, we demonstrate that systemic HGF treatment ameliorates EAE through the development of tolerogenic dendritic cells (DCs) with high expression levels of glucocorticoid-induced leucine zipper (GILZ), a transcriptional repressor of gene expression and a key endogenous regulator of the inflammatory response. RNA interference-directed neutralization of GILZ expression by DCs suppressed the induction of tolerance caused by HGF. Finally, adoptive transfer of HGF-treated DCs from wild-type but not GILZ gene-deficient mice potently mediated functional recovery in recipient mice with established EAE through effective modulation of autoaggressive T cell responses. Altogether, these results show that by inducing GILZ in DCs, HGF reproduces the mechanism of immune regulation induced by potent immunomodulatory factors such as IL-10, TGF-β1, and glucocorticoids and therefore that HGF therapy may have potential in the treatment of autoimmune dysfunctions. Copyright © 2014 by The American Association of Immunologists, Inc.

Dendritic cells in transplantation and immune-based therapies.

PubMed

Young, James W; Merad, Miriam; Hart, Derek N J

2007-01-01

Dendritic cells (DCs) are specialized, bone marrow-derived leukocytes critical to the onset of both innate and adaptive immunity. The divisions of labor among distinct human DC subtypes achieve the most effective balance between steady-state tolerance and the induction of innate and adaptive immunity against pathogens, tumors, and other insults. Maintenance of tolerance in the steady state is an active process involving resting or semimature DCs. Breakdowns in this homeostasis can result in autoimmunity. Perturbation of the steady state should first lead to the onset of innate immunity mediated by rapid responders in the form of plasmacytoid and monocyte-derived DC stimulators and natural killer (NK) and NK T-cell responders. These innate effectors then provide additional inflammatory cytokines, including interferon-gamma, which support the activation and maturation of resident and circulating populations of DCs. These are critical to the onset and expansion of adaptive immunity, including Th1, Th2, and cytotoxic T-lymphocyte responses. Rodent models are now revealing important data about distinct DC precursors, homeostasis of tissue-resident DCs, and DC turnover in response to inflammation and pathological conditions like graft-versus-host disease. The use of defined DC subtypes to stimulate both innate and adaptive immunity, either in combination or in a prime-boost vaccine sequence, may prove most useful clinically by harnessing both effector cell compartments.

Application of tissue-specific NK and NKT cell activity for tumor immunotherapy

PubMed Central

Subleski, Jeff J.; Wiltrout, Robert H.; Weiss, Jonathan M.

2009-01-01

Natural killer (NK) and NKT cells are a first line of defense against pathogens and transformed cells. However, dysregulation of their function can lead to autoimmune disease. A better understanding of the mechanisms controlling NK and NKT effector function should lead to the development of improved strategies for the treatment of many diseases. The site in which NK and NKT cells reside should be taken into account, because accumulating evidence suggests that the tissue microenvironment strongly influences their function. In this regard, the liver represents a unique immunologic organ in which the balance between the need for tolerance and the ability to respond rapidly to pathogens and tissue injury is tightly regulated. NK cells in the liver have augmented cytolytic activity as compared to other organs, which is consistent with a role for liver-associated NK cells in being critical effector cells for inhibiting tumor metastasis in the liver. Several studies also suggest that hepatic NKT cells have different functions than those in other organs. Whereas splenic and thymic NKT cells have been shown to suppress diabetes development, facilitate the induction of systemic tolerance and are regulated by IL-4 and other Th2 cytokines, certain subsets of NKT cells in the liver are important sources of Th1 cytokines such as Interferon gamma, and are the primary mediators of anti-tumor responses. The unique properties and roles as critical effector cells make NK and NKT cells within the liver microenvironment attractive targets of immunotherapeutic approaches that have the goal of controlling tumor metastasis in the liver. PMID:19682859

Thrombocytopenia associated with the induction of neonatal tolerance to alloantigens: immunopathogenic mechanisms.

PubMed

Merino, J; Qin, H Y; Schurmans, S; Gretener, D; Grau, G E; Lambert, P H

1989-09-01

BALB/c mice rendered tolerant to alloantigens by neonatal injection of semi-allogeneic (C57BL/6 x BALB/c)F1 spleen cells develop a thrombocytopenia in association with an autoimmune lupus-like syndrome. The possible mechanisms involved in the thrombocytopenia were investigated. The development of thrombocytopenia was first detected at 3 weeks of age coinciding with the start of the other autoimmune manifestations and was always related to a state of tolerance and B cell chimerism. There was a significant increase of megakaryocytes in bone marrow and spleens from thrombocytopenic tolerant mice and radiolabeled platelets from these mice were more rapidly eliminated from the bloodstream than normal platelets when injected into normal recipients. A significant correlation between the spleen weight and the decrease of the circulating platelets was observed, although some mice with severe thrombocytopenia had only a moderate spleen enlargement. Thrombocytopenia significantly correlates with the levels of platelet-associated IgG (PAIgG) but not with anti-single-stranded DNA antibodies or circulating immune complexes. Platelets from mice with high levels of PAIgG had a shorter life-span when injected into normal mice than those from mice with low or normal PAIgG. The possibility that PAIgG are partially due to antibodies reacting specifically with platelet membrane components was analyzed. First, F(ab')2 Ig fragments from tolerant mice were shown to bind to normal platelets, in contrast to F(ab')2 Ig fragments from normal mice. Second, some monoclonal antibodies produced by hybridomas derived from tolerant mice reacted in vitro with platelets and induced a transient thrombocytopenia after i.v. injection into normal mice. These data suggest that the thrombocytopenia observed in tolerant mice is the result of a peripheral hyperdestruction of platelets associated with (a) hypersplenism, (b) nonspecific fixation of immunoglobulins, probably as immune complexes and (c) with autoantibodies reacting specifically with platelets. It may represent an interesting model for human chronic idiopathic thrombocytopenia.

Novel vaccine development strategies for inducing mucosal immunity

PubMed Central

Fujkuyama, Yoshiko; Tokuhara, Daisuke; Kataoka, Kosuke; Gilbert, Rebekah S; McGhee, Jerry R; Yuki, Yoshikazu; Kiyono, Hiroshi; Fujihashi, Kohtaro

2012-01-01

To develop protective immune responses against mucosal pathogens, the delivery route and adjuvants for vaccination are important. The host, however, strives to maintain mucosal homeostasis by responding to mucosal antigens with tolerance, instead of immune activation. Thus, induction of mucosal immunity through vaccination is a rather difficult task, and potent mucosal adjuvants, vectors or other special delivery systems are often used, especially in the elderly. By taking advantage of the common mucosal immune system, the targeting of mucosal dendritic cells and microfold epithelial cells may facilitate the induction of effective mucosal immunity. Thus, novel routes of immunization and antigen delivery systems also show great potential for the development of effective and safe mucosal vaccines against various pathogens. The purpose of this review is to introduce several recent approaches to induce mucosal immunity to vaccines, with an emphasis on mucosal tissue targeting, new immunization routes and delivery systems. Defining the mechanisms of mucosal vaccines is as important as their efficacy and safety, and in this article, examples of recent approaches, which will likely accelerate progress in mucosal vaccine development, are discussed. PMID:22380827

Cytokine-free directed differentiation of human pluripotent stem cells efficiently produces hemogenic endothelium with lymphoid potential.

PubMed

Galat, Yekaterina; Dambaeva, Svetlana; Elcheva, Irina; Khanolkar, Aaruni; Beaman, Kenneth; Iannaccone, Philip M; Galat, Vasiliy

2017-03-17

The robust generation of human hematopoietic progenitor cells from induced or embryonic pluripotent stem cells would be beneficial for multiple areas of research, including mechanistic studies of hematopoiesis, the development of cellular therapies for autoimmune diseases, induced transplant tolerance, anticancer immunotherapies, disease modeling, and drug/toxicity screening. Over the past years, significant progress has been made in identifying effective protocols for hematopoietic differentiation from pluripotent stem cells and understanding stages of mesodermal, endothelial, and hematopoietic specification. Thus, it has been shown that variations in cytokine and inhibitory molecule treatments in the first few days of hematopoietic differentiation define primitive versus definitive potential of produced hematopoietic progenitor cells. The majority of current feeder-free, defined systems for hematopoietic induction from pluripotent stem cells include prolonged incubations with various cytokines that make the differentiation process complex and time consuming. We established that the application of Wnt agonist CHIR99021 efficiently promotes differentiation of human pluripotent stem cells in the absence of any hematopoietic cytokines to the stage of hemogenic endothelium capable of definitive hematopoiesis. The hemogenic endothelium differentiation was accomplished in an adherent, serum-free culture system by applying CHIR99021. Hemogenic endothelium progenitor cells were isolated on day 5 of differentiation and evaluated for their endothelial, myeloid, and lymphoid potential. Monolayer induction based on GSK3 inhibition, described here, yielded a large number of CD31 + CD34 + hemogenic endothelium cells. When isolated and propagated in adherent conditions, these progenitors gave rise to mature endothelium. When further cocultured with OP9 mouse stromal cells, these progenitors gave rise to various cells of myeloid lineages as well as natural killer lymphoid, T-lymphoid, and B-lymphoid cells. The results of this study substantiate a method that significantly reduces the complexity of current protocols for hematopoietic induction, offers a defined system to study the factors that affect the early stages of hematopoiesis, and provides a new route of lymphoid and myeloid cell derivation from human pluripotent stem cells, thus enhancing their use in translational medicine.

Noncoding RNA danger motifs bridge innate and adaptive immunity and are potent adjuvants for vaccination

PubMed Central

Wang, Lilin; Smith, Dan; Bot, Simona; Dellamary, Luis; Bloom, Amy; Bot, Adrian

2002-01-01

The adaptive immune response is triggered by recognition of T and B cell epitopes and is influenced by “danger” motifs that act via innate immune receptors. This study shows that motifs associated with noncoding RNA are essential features in the immune response reminiscent of viral infection, mediating rapid induction of proinflammatory chemokine expression, recruitment and activation of antigen-presenting cells, modulation of regulatory cytokines, subsequent differentiation of Th1 cells, isotype switching, and stimulation of cross-priming. The heterogeneity of RNA-associated motifs results in differential binding to cellular receptors, and specifically impacts the immune profile. Naturally occurring double-stranded RNA (dsRNA) triggered activation of dendritic cells and enhancement of specific immunity, similar to selected synthetic dsRNA motifs. Based on the ability of specific RNA motifs to block tolerance induction and effectively organize the immune defense during viral infection, we conclude that such RNA species are potent danger motifs. We also demonstrate the feasibility of using selected RNA motifs as adjuvants in the context of novel aerosol carriers for optimizing the immune response to subunit vaccines. In conclusion, RNA-associated motifs produced during viral infection bridge the early response with the late adaptive phase, regulating the activation and differentiation of antigen-specific B and T cells, in addition to a short-term impact on innate immunity. PMID:12393853

A Bone Anabolic Effect of RANKL in a Murine Model of Osteoporosis mediated through FoxP3+ CD8 T-cells

PubMed Central

Buchwald, Zachary S.; Yang, Chang; Nellore, Suman; Shashkova, Elena V.; Davis, Jennifer L.; Cline, Anna; Ko, Je; Novack, Deborah V.; DiPaolo, Richard; Aurora, Rajeev

2015-01-01

TNFα and IL-17 secreted by proinflammatory T-cells (TEFF) promote bone erosion by activating osteoclasts. We previously demonstrated that in addition to bone resorption, osteoclasts act as antigen presenting cells to induce FoxP3 in CD8 T-cells (TcREG). The osteoclast-induced regulatory CD8 T-cells limit bone resorption in ovariectomized mice (a murine model of postmenopausal osteoporosis). Here we show that while low-dose RANKL maximally induces TcREG via Notch signaling pathway to limit bone resorption, high-dose RANKL promotes bone resorption. In vitro, both TNFα and IL-17, cytokines that are abundant in ovariectomized animals, suppress TcREG induction by osteoclasts by repressing Notch ligand expression in osteoclasts but this effect can be counteracted by addition of RANKL. Ovariectomized mice treated with low-dose RANKL induced TcREG that suppressed bone resorption, decreased TEFF levels and increased bone formation. High dose RANKL had the expected osteolytic effect. Low dose RANKL administration in ovariectomized mice lacking CD8 T-cells was also osteolytic, confirming that TcREG mediate this bone anabolic effect. Our results show that while RANKL directly stimulates osteoclasts to resorb bone, it also controls the osteoclasts’ ability to induce regulatory T-cells, engaging an important negative feedback loop. In addition to the conceivable clinical relevance to treatment of osteoporosis, these observations have potential relevance to induction of tolerance and autoimmune diseases. PMID:25656537

Ethanol Reversal of Cellular Tolerance to Morphine in Rat Locus Coeruleus Neurons

PubMed Central

Llorente, Javier; Withey, Sarah; Rivero, Guadalupe; Cunningham, Margaret; Cooke, Alex; Saxena, Kunal; McPherson, Jamie; Oldfield, Sue; Dewey, William L.; Bailey, Chris P.; Kelly, Eamonn; Henderson, Graeme

2013-01-01

Consumption of ethanol is a considerable risk factor for death in heroin overdose. We sought to determine whether a mildly intoxicating concentration of ethanol could alter morphine tolerance at the cellular level. In rat locus coeruleus (LC) neurons, tolerance to morphine was reversed by acute exposure of the brain slice to ethanol (20 mM). Tolerance to the opioid peptide [d-Ala2,N-MePhe4,Gly-ol]-enkephalin was not reversed by ethanol. Previous studies in LC neurons have revealed a role for protein kinase C (PKC)α in μ-opioid receptor (MOPr) desensitization by morphine and in the induction and maintenance of morphine tolerance, but we have been unable to demonstrate that 20 mM ethanol produces significant inhibition of PKCα. The ability of ethanol to reverse cellular tolerance to morphine in LC neurons was absent in the presence of the phosphatase inhibitor okadaic acid, indicating that dephosphorylation is involved. In human embryonic kidney 293 cells expressing the MOPr, ethanol reduced the level of MOPr phosphorylation induced by morphine. Ethanol reversal of tolerance did not appear to result from a direct effect on MOPr since acute exposure to ethanol (20 mM) did not modify the affinity of binding of morphine to the MOPr or the efficacy of morphine for G-protein activation as measured by guanosine 5′-O-(3-[35S]thio)triphosphate binding. Similarly, ethanol did not affect MOPr trafficking. We conclude that acute exposure to ethanol enhances the effects of morphine by reversing the processes underlying morphine cellular tolerance. PMID:23716621

Cervical (pre)neoplastic microenvironment promotes the emergence of tolerogenic dendritic cells via RANKL secretion

PubMed Central

Demoulin, Stéphanie A; Somja, Joan; Duray, Anaëlle; Guénin, Samuel; Roncarati, Patrick; Delvenne, Philippe O; Herfs, Michael F; Hubert, Pascale M

2015-01-01

The progression of genital human papillomavirus (HPV) infections into preneoplastic lesions suggests that infected/malignant cells are not adequately recognized by the immune system. In this study, we demonstrated that cervical/vulvar cancer cells secrete factor(s) that affect both the maturation and function of dendritic cells (DC) leading to a tolerogenic profile. Indeed, DC cocultured with cancer cell lines display both a partially mature phenotype after lipopolysaccharide (LPS) maturation and an altered secretory profile (IL-10high and IL-12p70low). In addition, tumor-converted DC acquire the ability to alter T-cell proliferation and to induce FoxP3+ suppressive T cells from naive CD4+ T cells. Among the immunosuppressive factors implicated in DC alterations in genital (pre)neoplastic microenvironment, we identified receptor activator of nuclear factor kappa-B ligand (RANKL), a TNF family member, as a potential candidate. For the first time, we showed that RANKL expression strongly increases during cervical progression. We also confirmed that RANKL is directly secreted by cancer cells and this expression is not related to HPV viral oncoprotein induction. Interestingly, the addition of osteoprotegerin (OPG) in coculture experiments reduces significantly the inhibition of DC maturation, the release of a tolerogenic cytokine profile (IL-12low IL-10high) and the induction of regulatory T (Treg) cells. Our findings suggest that the use of inhibitory molecules directed against RANKL in cervical/vulvar (pre)neoplastic lesions might prevent alterations of DC functionality and represent an attractive strategy to overcome immune tolerance in such cancers. PMID:26155412

Obg and Membrane Depolarization Are Part of a Microbial Bet-Hedging Strategy that Leads to Antibiotic Tolerance.

PubMed

Verstraeten, Natalie; Knapen, Wouter Joris; Kint, Cyrielle Ines; Liebens, Veerle; Van den Bergh, Bram; Dewachter, Liselot; Michiels, Joran Elie; Fu, Qiang; David, Charlotte Claudia; Fierro, Ana Carolina; Marchal, Kathleen; Beirlant, Jan; Versées, Wim; Hofkens, Johan; Jansen, Maarten; Fauvart, Maarten; Michiels, Jan

2015-07-02

Within bacterial populations, a small fraction of persister cells is transiently capable of surviving exposure to lethal doses of antibiotics. As a bet-hedging strategy, persistence levels are determined both by stochastic induction and by environmental stimuli called responsive diversification. Little is known about the mechanisms that link the low frequency of persisters to environmental signals. Our results support a central role for the conserved GTPase Obg in determining persistence in Escherichia coli in response to nutrient starvation. Obg-mediated persistence requires the stringent response alarmone (p)ppGpp and proceeds through transcriptional control of the hokB-sokB type I toxin-antitoxin module. In individual cells, increased Obg levels induce HokB expression, which in turn results in a collapse of the membrane potential, leading to dormancy. Obg also controls persistence in Pseudomonas aeruginosa and thus constitutes a conserved regulator of antibiotic tolerance. Combined, our findings signify an important step toward unraveling shared genetic mechanisms underlying persistence. Copyright © 2015 Elsevier Inc. All rights reserved.

Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease

PubMed Central

Sherif , S. M.; Shukla, M. R.; Murch, S. J.; Bernier, L.; Saxena, P. K.

2016-01-01

Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions. PMID:26902398

[CD4 + CD25 + regulatory T cells and their importance to human illnesses].

PubMed

Kelsen, Jens; Hvas, Christian Lodberg; Agnholt, Jørgen; Dahlerup, Jens F

2006-01-03

Regulatory T cells ensure a balanced immune response that is competent both to fight pathogens, at the same time, to recognize self-antigens and commensals as harmless. Regulatory mechanisms are essential in preventing autoimmune disorders but may also facilitate the progression of malignant diseases and the establishment of latent infections via suppression of the host immune response. Regulatory T cells arise in the thymus, and regulatory T cell function can be induced in the periphery, so-called infectious tolerance. An absolute or relative defect in regulatory T cell function may contribute to the development of autoimmune disorders such as rheumatoid arthritis, type 1 diabetes mellitus, multiple sclerosis and chronic inflammatory bowel disease. Regulatory T cell therapy is a tempting strategy for reestablishing the immune balance and thus preventing or reversing these disorders. Reestablishment of the immune balance may be accomplished by adoptive transfer of ex vivo-propagated regulatory T cells or by induction of regulatory functions locally in the organs, although such strategies are in their infancy in human research.

NDRG2 overexpression suppresses hepatoma cells survival during metabolic stress through disturbing the activation of fatty acid oxidation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Tao; Xi'an Medical University, Xi'an, Shaanxi Province; Zhang, Mei

Because of the high nutrient consumption and inadequate vascularization, solid tumor constantly undergoes metabolic stress during tumor development. Oncogenes and tumor suppressor genes participated in cancer cells' metabolic reprogramming. N-Myc downstream regulated gene 2 (NDRG2) is a recently identified tumor suppressor gene, but its function in cancer metabolism, particularly during metabolic stress, remains unclear. In this study, we found that NDRG2 overexpression significantly reduced hepatoma cell proliferation and enhanced cell apoptosis under glucose limitation. Moreover, NDRG2 overexpression aggravated energy imbalance and oxidative stress by decreasing the intracellular ATP and NADPH generation and increasing ROS levels. Strikingly, NDRG2 inhibited the activationmore » of fatty acid oxidation (FAO), which preserves ATP and NADPH purveyance in the absence of glucose. Finally, mechanistic investigation showed that NDRG2 overexpression suppressed the glucose-deprivation induced AMPK/ACC pathway activation in hepatoma cells, whereas the expression of a constitutively active form of AMPK abrogated glucose-deprivation induced AMPK activation and cell apoptosis. Thus, as a negative regulator of AMPK, NDRG2 disturbs the induction of FAO genes by glucose limitation, leading to dysregulation of ATP and NADPH, and thus reduces the tolerance of hepatoma cells to glucose limitation. - Highlights: • NDRG2 overexpression reduces the tolerance of hepatoma cells to glucose limitation. • NDRG2 overexpression aggravates energy imbalance and oxidative stress under glucose deprivation. • NDRG2 overexpression disturbs the activation of FAO in hepatoma cells under glucose limitation. • NDRG2 overexpression inhibits the activation of AMPK/ACC pathway in hepatoma cells during glucose starvation.« less

The dectin-1/inflammasome pathway is responsible for the induction of protective T-helper 17 responses that discriminate between yeasts and hyphae of Candida albicans.

PubMed

Cheng, Shih-Chin; van de Veerdonk, Frank L; Lenardon, Megan; Stoffels, Monique; Plantinga, Theo; Smeekens, Sanne; Rizzetto, Lisa; Mukaremera, Liliane; Preechasuth, Kanya; Cavalieri, Duccio; Kanneganti, Thirumala Devi; van der Meer, Jos W M; Kullberg, Bart Jan; Joosten, Leo A B; Gow, Neil A R; Netea, Mihai G

2011-08-01

In the mucosa, the immune pathways discriminating between colonizing and invasive Candida, thus inducing tolerance or inflammation, are poorly understood. Th17 responses induced by Candida albicans hyphae are central for the activation of mucosal antifungal immunity. An essential step for the discrimination between yeasts and hyphae and induction of Th17 responses is the activation of the inflammasome by C. albicans hyphae and the subsequent release of active IL-1β in macrophages. Inflammasome activation in macrophages results from differences in cell-wall architecture between yeasts and hyphae and is partly mediated by the dectin-1/Syk pathway. These results define the dectin-1/inflammasome pathway as the mechanism that enables the host immune system to mount a protective Th17 response and distinguish between colonization and tissue invasion by C. albicans.

Dendritic cell subsets in type 1 diabetes: friend or foe?

PubMed

Morel, Penelope A

2013-12-06

Type 1 diabetes (T1D) is a T cell mediated autoimmune disease characterized by immune mediated destruction of the insulin-producing β cells in the islets of Langerhans. Dendritic cells (DC) have been implicated in the pathogenesis of T1D and are also used as immunotherapeutic agents. Plasmacytoid (p)DC have been shown to have both protective and pathogenic effects and a newly described merocytic DC population has been shown to break tolerance in the mouse model of T1D, the non-obese diabetic (NOD) mouse. We have used DC populations to prevent the onset of T1D in NOD mice and clinical trials of DC therapy in T1D diabetes have been initiated. In this review we will critically examine the recent published literature on the role of DC subsets in the induction and regulation of the autoimmune response in T1D.

Stem cell and genetic therapies for the fetus.

PubMed

Roybal, Jessica L; Santore, Matthew T; Flake, Alan W

2010-02-01

Advances in prenatal diagnosis have led to the prenatal management of a variety of congenital diseases. Although prenatal stem cell and gene therapy await clinical application, they offer tremendous potential for the treatment of many genetic disorders. Normal developmental events in the fetus offer unique biologic advantages for the engraftment of hematopoietic stem cells and efficient gene transfer that are not present after birth. Although barriers to hematopoietic stem cell engraftment exist, progress has been made and preclinical studies are now underway for strategies based on prenatal tolerance induction to facilitate postnatal cellular transplantation. Similarly, in-utero gene therapy shows experimental promise for a host of diseases and proof-in-principle has been demonstrated in murine models, but ethical and safety issues still need to be addressed. Here we review the current status and future potential of prenatal cellular and genetic therapy. Copyright 2009 Elsevier Ltd. All rights reserved.

Low Dose Decitabine Treatment Induces CD80 Expression in Cancer Cells and Stimulates Tumor Specific Cytotoxic T Lymphocyte Responses

PubMed Central

Zhou, Ji-Hao; Yao, Yu-Shi; Li, Yong-Hui; Xu, Yi-Han; Li, Jing-Xin; Gao, Xiao-Ning; Zhou, Min-Hang; Jiang, Meng-Meng; Gao, Li; Ding, Yi; Lu, Xue-Chun; Shi, Jin-Long; Luo, Xu-Feng; Wang, Jia; Wang, Li-Li; Qu, Chunfeng; Bai, Xue-Feng; Yu, Li

2013-01-01

Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC), a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL) response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight) once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8+, but not CD4+ T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy. PMID:23671644

Low dose decitabine treatment induces CD80 expression in cancer cells and stimulates tumor specific cytotoxic T lymphocyte responses.

PubMed

Wang, Li-Xin; Mei, Zhen-Yang; Zhou, Ji-Hao; Yao, Yu-Shi; Li, Yong-Hui; Xu, Yi-Han; Li, Jing-Xin; Gao, Xiao-Ning; Zhou, Min-Hang; Jiang, Meng-Meng; Gao, Li; Ding, Yi; Lu, Xue-Chun; Shi, Jin-Long; Luo, Xu-Feng; Wang, Jia; Wang, Li-Li; Qu, Chunfeng; Bai, Xue-Feng; Yu, Li

2013-01-01

Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC), a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL) response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight) once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8(+), but not CD4(+) T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy.

The sunflower transcription factor HaWRKY76 confers drought and flood tolerance to Arabidopsis thaliana plants without yield penalty.

PubMed

Raineri, Jesica; Ribichich, Karina F; Chan, Raquel L

2015-12-01

Arabidopsis transgenic plants expressing the sunflower transcription factor HaWRKY76 exhibit increased yield and tolerance to drought and flood stresses. The genetic construct containing HaWRKY76 is proposed as a potential biotechnological tool to improve crops. Water deficit and water excess are abiotic stress factors that seriously affect crops worldwide. To increase the tolerance to such stresses without causing yield penalty constitutes a major goal for biotechnologists. In this survey, we report that HaWRKY76, a divergent sunflower WRKY transcription factor, is able to confer both dehydration and submergence tolerance to Arabidopsis transgenic plants without yield penalty. The expression pattern of HaWRKY76 was analyzed in plants grown in standard conditions and under different watering regimes indicating a regulation by water availability. The corresponding cDNA was isolated and cloned under the control of a constitutive promoter and Arabidopsis plants were transformed with this construct. These transgenic plants presented higher biomass, seed production and sucrose content than controls in standard growth conditions. Moreover, they exhibited tolerance to mild drought or flood (complete submergence/waterlogging) stresses as well as the same or increased yield, depending on the stress severity and plant developmental stage, compared with controls. Drought tolerance occurred via an ABA-independent mechanism and induction of stomatal closure. Submergence tolerance can be explained by the carbohydrate (sucrose and starch) preservation achieved through the repression of fermentation pathways. Higher cell membrane stability and chlorenchyma maintenance could be the nexus between tolerance responses in front of both stresses. Altogether, the obtained results indicated that HaWRKY76 can be a potential biotechnological tool to improve crops yield as well as drought and flood tolerances.

Antimicrobial Tolerance of Pseudomonas aeruginosa Biofilms Is Activated during an Early Developmental Stage and Requires the Two-Component Hybrid SagS

PubMed Central

Gupta, Kajal; Marques, Cláudia N. H.; Petrova, Olga E.

2013-01-01

A hallmark characteristic of biofilms is their extraordinary tolerance to antimicrobial agents. While multiple factors are thought to contribute to the high level of antimicrobial tolerance of biofilms, little is known about the timing of induction of biofilm tolerance. Here, we asked when over the course of their development do biofilms gain their tolerance to antimicrobial agents? We demonstrate that in Pseudomonas aeruginosa, biofilm tolerance is linked to biofilm development, with transition to the irreversible attachment stage regulated by the two-component hybrid SagS, marking the timing when biofilms switch to the high-level tolerance phenotype. Inactivation of sagS rendered biofilms but not planktonic cells more susceptible to tobramycin, norfloxacin, and hydrogen peroxide. Moreover, inactivation of sagS also eliminated the recalcitrance of biofilms to killing by bactericidal antimicrobial agents, a phenotype comparable to that observed upon inactivation of brlR, which encodes a MerR-like transcriptional regulator required for biofilm tolerance. Multicopy expression of brlR in a ΔsagS mutant restored biofilm resistance and recalcitrance to killing by bactericidal antibiotics to wild-type levels. In contrast, expression of sagS did not restore the susceptibility phenotype of ΔbrlR mutant biofilms to wild-type levels, indicating that BrlR functions downstream of SagS. Inactivation of sagS correlated with reduced BrlR levels in biofilms, with the produced BrlR being impaired in binding to the previously described BrlR-activated promoters of the two multidrug efflux pump operons mexAB-oprM and mexEF-oprN. Our findings demonstrate that biofilm tolerance is linked to early biofilm development and SagS, with SagS contributing indirectly to BrlR activation. PMID:23995639

Kidney versus Islet Allograft Survival after Induction of Mixed Chimerism with Combined Donor Bone Marrow Transplantation

PubMed Central

Oura, Tetsu; Ko, Dicken S.C.; Boskovic, Svjetlan; O'Neil, John J.; Chipashvili, Vaja; Koulmanda, Maria; Hotta, Kiyohiko; Kawai, Kento; Nadazdin, Ognjenka; Smith, R. Neal; Cosimi, A. B.; Kawai, Tatsuo

2016-01-01

Background We have previously reported successful induction of transient mixed chimerism and long-term acceptance of renal allografts in MHC-mismatched nonhuman primates. In this study, we attempted to extend this tolerance induction approach to islet allografts. Methods A total of eight recipients underwent MHC mismatched combined islet and bone marrow (BM) transplantation after induction of diabetes by streptozotocin. Three recipients were treated after a nonmyeloablative conditioning regimen that includes low dose total body and thymic irradiation, horse ATG (Atgam), six doses of anti-CD154 monoclonal antibody (mAb) and a one month course of cyclosporine (CyA) (Islet-A). In Islet-B, anti-CD8 mAb was administered in place of CyA. In Islet-C, two recipients were treated with Islet-B but without Atgam. The results were compared with previously reported results of eight cynomolgus monkeys that received combined kidney and bone marrow transplantation (Kidney-A) following the same conditioning regimen used in Islet-A. Results The majority of Kidney/BM recipients achieved long-term renal allograft survival after induction of transient chimerism. However, prolonged islet survival was not achieved in similarly conditioned Islet/BM recipients (Islet-A), despite induction of comparable levels of chimerism. In order to rule out islet allograft loss due to calcineurin inhibitor (CNI) toxicity, three recipients were treated with anti-CD8 mAb in place of CNI. Although these recipients developed significantly superior mixed chimerism and more prolonged islet allograft survival (61, 103, and 113 days), islet function was lost soon after the disappearance of chimerism. In Islet-C recipients, neither prolonged chimerism nor islet survival was observed (30 and 40 days). Conclusion Significant improvement of mixed chimerism induction and islet allograft survival were achieved with a CNI-free regimen that includes anti-CD8 mAb. However, unlike the kidney allograft, islet allograft tolerance was not induced with transient chimerism. Induction of more durable mixed chimerism may be necessary for induction of islet allograft tolerance. PMID:26337731

Recombinant modified vaccinia virus Ankara-based malaria vaccines.

PubMed

Sebastian, Sarah; Gilbert, Sarah C

2016-01-01

A safe and effective malaria vaccine is a crucial part of the roadmap to malaria elimination/eradication by the year 2050. Viral-vectored vaccines based on adenoviruses and modified vaccinia virus Ankara (MVA) expressing malaria immunogens are currently being used in heterologous prime-boost regimes in clinical trials for induction of strong antigen-specific T-cell responses and high-titer antibodies. Recombinant MVA is a safe and well-tolerated attenuated vector that has consistently shown significant boosting potential. Advances have been made in large-scale MVA manufacture as high-yield producer cell lines and high-throughput purification processes have recently been developed. This review describes the use of MVA as malaria vaccine vector in both preclinical and clinical studies in the past 5 years.

Antigen-specific therapy of Graves´ disease and orbitopathy by induction of tolerance.

PubMed

Ungerer, Martin; Fabbender, Julia; Holthoff, Hans-Peter

2018-06-01

Graves´ disease is an autoimmune disorder, which is characterized by stimulatory antibodies targeting the human thyrotropin receptor (TSHR), resulting in hyperthyroidism and multiple organ damage. The disease can be modelled in mice using adenoviral immunizations with the extracellular A subunit of the TSHR, which induces a long-term stable disease state. TSHR binding cAMP-stimulatory antibodies, thyroid enlargement, elevated serum thyroxin levels, tachycardia, cardiac hypertrophy and orbitopathy are observed in these Ad-TSHR-immunized mice. T cell epitope-derived linear peptides have been identified using immunized HLA-DR3 transgenic mice, which may induce tolerance towards TSHR. A combination of such peptides are being investigated in a first clinical phase I trial in patients with Graves´ disease. Alternatively, intravenous administration of cyclic peptides derived from the interaction site of the TSHR A domain with stimulatory anti-TSHR antibodies can re-establish tolerance towards the antigen in immunized mice, improving symptoms of Graves´ disease within 3 - 4 months after starting these therapies. In immunologically naïve mice, administration of the cyclic peptides did not induce any immune response.

The Potential of Nano-Vehicle Mediated Therapy in Vasculitis and Multiple Sclerosis.

PubMed

In't Veld, R Huis; Da Silva, C G; Kaijzel, E L; Chan, A B; Cruz, L J

2017-01-01

The induction of immune tolerance towards self-antigens presents as a viable future strategy in the treatment of auto-immune diseases, including vasculitis and multiple sclerosis (MS). As specific targets are currently lacking for vasculitis due to incomplete understanding of the pathologies underlying this disease, current treatment options are based on modalities that induce general immune suppression. However, many immune suppressants used in the clinic are known to display wide biodistribution and are thus often accompanied by several adverse effects. Nano-vehicles (NVs) possess the ability to overcome such limitations by enabling more specific delivery of their content through modifications with targeting moieties. In this review, we describe the latest insights in the pathology of vasculitis that may function as potential targets for NV carrier systems, allowing more specific delivery of currently used immune suppressants. In addition, we describe the existing strategies to induce artificial immune tolerance and explore the feasibility of inducing regulatory T cell (Treg) mediated tolerance for MS, possibly mediated by NVs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Aging and sleep deprivation induce the unfolded protein response in the pancreas: implications for metabolism

PubMed Central

Naidoo, Nirinjini; Davis, James G; Zhu, Jingxu; Yabumoto, Maya; Singletary, Kristan; Brown, Marishka; Galante, Raymond; Agarwal, Beamon; Baur, Joseph A

2014-01-01

Sleep disruption has detrimental effects on glucose metabolism through pathways that remain poorly defined. Although numerous studies have examined the consequences of sleep deprivation (SD) in the brain, few have directly tested its effects on peripheral organs. We examined several tissues in mice for induction of the unfolded protein response (UPR) following acute SD. In young animals, we found a robust induction of BiP in the pancreas, indicating an active UPR. At baseline, pancreata from aged animals exhibited a marked increase in a pro-apoptotic transcription factor, CHOP, that was amplified by SD, whereas BiP induction was not observed, suggesting a maladaptive response to cellular stress with age. Acute SD increased plasma glucose levels in both young and old animals. However, this change was not overtly related to stress in the pancreatic beta cells, as plasma insulin levels were not lower following acute SD. Accordingly, animals subjected to acute SD remained tolerant to a glucose challenge. In a chronic SD experiment, young mice were found to be sensitized to insulin and have improved glycemic control, whereas aged animals became hyperglycemic and failed to maintain appropriate plasma insulin concentrations. Our results show that both age and SD cooperate to induce the UPR in pancreatic tissue. While changes in insulin secretion are unlikely to play a major role in the acute effects of SD, CHOP induction in pancreatic tissues suggests that chronic SD may contribute to the loss or dysfunction of endocrine cells and that these effects may be exacerbated by normal aging. PMID:24102714

Granulocytic myeloid-derived suppressor cells from human cord blood modulate T-helper cell response towards an anti-inflammatory phenotype.

PubMed

Köstlin, Natascha; Vogelmann, Margit; Spring, Bärbel; Schwarz, Julian; Feucht, Judith; Härtel, Christoph; Orlikowsky, Thorsten W; Poets, Christian F; Gille, Christian

2017-09-01

Infections are a leading cause of perinatal morbidity and mortality. The outstandingly high susceptibility to infections early in life is mainly attributable to the compromised state of the neonatal immune system. One important difference to the adult immune system is a bias towards T helper type 2 (Th2) responses in newborns. However, mechanisms regulating neonatal T-cell responses are incompletely understood. Granulocytic myeloid-derived suppressor cells (GR-MDSC) are myeloid cells with a granulocytic phenotype that suppress various functions of other immune cells and accumulate under physiological conditions during pregnancy in maternal and fetal blood. Although it has been hypothesized that GR-MDSC accumulation during fetal life could be important for the maintenance of maternal-fetal tolerance, the influence of GR-MDSC on the immunological phenotype of neonates is still unclear. Here, we investigated the impact of GR-MDSC isolated from cord blood (CB-MDSC) on the polarization of Th cells. We demonstrate that CB-MDSC inhibit Th1 responses and induced Th2 responses and regulatory T (Treg) cells. Th1 inhibition was cell-contact dependent and occurred independent of other cell types, while Th2 induction was mediated independently of cell contact through expression of ArgI and reactive oxygen species by CB-MDSC and partially needed the presence of monocytes. Treg cell induction by CB-MDSC also occurred cell-contact independently but was partially mediated through inducible nitric oxide synthase. These results point towards a role of MDSC in regulating neonatal immune responses. Targeting MDSC function in neonates could be a therapeutic opportunity to improve neonatal host defence. © 2017 John Wiley & Sons Ltd.

Interaction between dendritic cells and natural killer cells during pregnancy in mice.

PubMed

Blois, Sandra M; Barrientos, Gabriela; Garcia, Mariana G; Orsal, Arif S; Tometten, Mareike; Cordo-Russo, Rosalia I; Klapp, Burghard F; Santoni, Angela; Fernández, Nelson; Terness, Peter; Arck, Petra C

2008-07-01

A complex regulation of innate and adaptive immune responses at the maternal fetal interface promotes tolerance of trophoblast cells carrying paternally derived antigens. Such regulatory functions involve uterine dendritic cells (uDC) and natural killer (uNK) cells. The existence of a NK and DC "cross talk" has been revealed in various experimental settings; its biological significance ranging from cooperative stimulation to cell lysis. Little is known about the presence or role of NK and DC cross talk at the maternal fetal interface. The present study shows that mouse NK and DC interactions are subject to modulation by trophoblast cells in vitro. This interaction promotes a tolerogenic microenvironment characterized by downregulation of the expression of activation markers on uNK cells and uDC and dominance of Th2 cytokines. NK and DC interactions would also influence uterine cell proliferation and this process would be strongly modulated by trophoblast-derived signals. Indeed; while low proliferation rates were observed upon regular coculture allowing direct contact between uterine cells and trophoblasts, incubation in a transwell culture system markedly increased uterine cell proliferation suggesting that soluble factors are key mediators in the molecular "dialog" between the mother and the conceptus during the establishment of mouse pregnancy. Our data further reveal that the regulatory functions of trophoblast cells associated with tolerance induction are impaired in high abortion murine matings. Interestingly, we observed that secretion of interleukin-12p70 by uDC is dramatically abrogated in the presence of uNK cells. Taken together, our results provide the first evidence that a delicate balance of interactions involving NK cells, DC, and trophoblasts at the mouse maternal fetal interface supports a successful pregnancy outcome.

Misalignment tolerable coil structure for biomedical applications with wireless power transfer.

PubMed

Chow, Jeff P W; Chen, Nan; Chung, Henry S H; Chan, Leanne L H

2013-01-01

Coil-misalignment is one of the major hurdles for inductively coupled wireless power transfer in applications like retinal prosthesis. Weak magnetic flux linkage due to coil misalignments would significantly impair the power efficiency. A novel receiver configuration with high misalignment tolerance is presented in this paper. The proposed receiver is composed of two receiver coils placed orthogonally, so as to reduce the variation of mutual inductance between transmitting and receiving coils under misalignment conditions. Three different receiver coil structures are analyzed and compared using the same length of wire. Theoretical predictions have been confirmed with measurement results.

Ultraviolet light-induced keratinocyte apoptosis: a potential mechanism for the induction of skin lesions and autoantibody production in LE.

PubMed

Casciola-Rosen, L; Rosen, A

1997-01-01

Systemic lupus erythematosus (SLE) is a prototype systemic autoimmune disease which is characterized clinically by pleiotropy and periodicity. The immune features which accompany the characteristic flares of the disease have strongly suggested that the autoimmune response is driven by self antigen, and is T cell-dependent. These features have prompted the search for potential initiating process(es) which induce the release of self-antigens in a form which causes T cell tolerance to those self molecules to be broken. We review here several recent observations which implicate apoptotic cells as an important potential source of clustered and concentrated autoantigens in SLE, and present our current model whereby the novel autoantigen fragments generated in apoptotic surface blebs initiate and drive the autoimmune response in this disease.

Measuring T cell cytokines in allergic upper and lower airway inflammation: can we move to the clinic?

PubMed

Bullens, Dominique M A

2007-06-01

Recent insights regarding the development of allergic diseases such as allergic rhinitis, asthma and atopic eczema are based on the functional diversity of T helper (Th)1 and Th2 lymphocytes. Th2 cells (secreting Interleukin (IL)-4, IL-5, IL-9 and IL-13) are considered to be responsible for the induction and for many of the manifestations of atopic diseases. Local overproduction of Th2 cytokines at the site of allergic inflammation, and an intrinsic defect in the production of IFN-gamma by Th1 cells in atopic individuals, have now been reported by several authors. Both IFN-gamma and IL-10 have been suggested to play a modulatory role in the induction and maintenance of allergen-specific tolerance in healthy individuals. However, recent studies indicate that Th1 cells, secreting IFN-gamma might cause severe airway inflammation. On the other hand, 'inflammatory T cells' or Th17 cells, producing IL-17, could represent a link between T cell inflammation and granulocytic influx as observed in allergic airway inflammation. We focus in this review on local (at the side of inflammation) T cell cytokine production and cytokine production by circulating T cells (after in vitro restimulation) from individuals with allergic airway disease, rhinitis and/or asthma. We furthermore review the changes in local T cell cytokine production and/or cytokine production by circulating T cells (after restimulation in vitro) from allergic/asthmatic individuals after treatment with anti-inflammatory agents or immunotherapy. Finally, we discuss whether measuring these T cell cytokines in the airways might be of diagnostic importance or could help to follow-up patients with allergy/asthma.

Ionizing radiation and autoimmunity: Induction of autoimmune disease in mice by high dose fractionated total lymphoid irradiation and its prevention by inoculating normal T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakaguchi, N.; Sakaguchi, S.; Miyai, K.

1992-11-01

Ionizing radiation can functionally alter the immune system and break self-tolerance. High dose (42.5 Gy), fractionated (2.5 Gy 17 times) total lymphoid irradiation (TLI) on mice caused various organ-specific autoimmune diseases, such as gastritis, thyroiditis, and orchitis, depending on the radiation dosages, the extent of lymphoid irradiation, and the genetic background of the mouse strains. Radiation-induced tissue damage is not the primary cause of the autoimmune disease because irradiation of the target organs alone failed to elicit the autoimmunity and shielding of the organs from irradiation was unable to prevent it. In contrast, irradiation of both the thymus and themore » peripheral lymphoid organs/tissues was required for efficient induction of autoimmune disease by TLI. TLI eliminated the majority of mature thymocytes and the peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or bone marrow cell suspensions (prepared from syngeneic nonirradiated mice) within 2 wk after TLI effectively prevented the autoimmune development. Depletion of T cells from the inocula abrogated the preventive activity. CD4[sup +] T cells mediated the autoimmune prevention but CD8[sup +] T cells did not. CD4[sup +] T cells also appeared to mediate the TLI-induced autoimmune disease because CD4[sup +] T cells from disease-bearing TLI mice adoptively transferred the autoimmune disease to syngeneic naive mice. Taken together, these results indicate that high dose, fractionated ionizing radiation on the lymphoid organs/tissues can cause autoimmune disease by affecting the T cell immune system, rather than the target self-Ags, presumably by altering T cell-dependent control of self-reactive T cells. 62 refs., 9 figs., 2 tabs.« less

Long survival and immunologic reconstitution following transplantation with syngeneic or allogeneic fetal liver and neonatal spleen cells. [X radiation, mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yunis, E.J.; Fernandes, G.; Smith, J.

1976-12-01

Spleen cells from newborn syngeneic and allogeneic mice that lack fully differentiated T lymphocytes can be used as a hematopoietic source to reconstitute both hematopoietic and lymphoid systems of lethally irradiated mice without producing a GVHR. Fetal liver cells from syngeneic and allogeneic mice that lack postthymic T lymphocytes can also be used for hematopoietic and immunologic reconstitution of lethally irradiated mice without producing GVHR. Immunologic deficiency is observed in some experiments in mice given supralethal irradiation (1000 R) and fetal liver as reconstituting hematopoietic tissue. The findings suggest that T cells, at an early stage of differentiation, are moremore » susceptible to tolerance induction than are T lymphocytes at later stages of differentiation and do not, in general, produce GVHR. It is postulated that hematopoietic cells, free of postthymic lymphoid cells, can be used for hematopoietic or immunologic reconstitution and celular engineering without producing GVHD.« less

Ibrutinib: a first in class covalent inhibitor of Bruton’s tyrosine kinase

PubMed Central

Davids, Matthew S; Brown, Jennifer R

2015-01-01

Ibrutinib (formerly PCI-32765) is a potent, covalent inhibitor of Bruton’s tyrosine kinase, a kinase downstream of the B-cell receptor that is critical for B-cell survival and proliferation. In preclinical studies, ibrutinib bound to Bruton’s tyrosine kinase with high affinity, leading to inhibition of B-cell receptor signaling, decreased B-cell activation and induction of apoptosis. In clinical studies, ibrutinib has been well-tolerated and has demonstrated profound anti-tumor activity in a variety of hematologic malignancies, most notably chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), leading to US FDA approval for relapsed CLL and MCL. Ongoing studies are evaluating ibrutinib in other types of non-Hodgkin’s lymphoma, such as diffuse large B-cell lymphoma and Waldenström’s macrogobulinemia, in larger Phase III studies in CLL and MCL, and in combination studies with monoclonal antibodies and chemotherapy. Future studies will combine ibrutinib with other promising novel agents currently in development in hematologic malignancies. PMID:24941982

Ibrutinib: a first in class covalent inhibitor of Bruton's tyrosine kinase.

PubMed

Davids, Matthew S; Brown, Jennifer R

2014-05-01

Ibrutinib (formerly PCI-32765) is a potent, covalent inhibitor of Bruton's tyrosine kinase, a kinase downstream of the B-cell receptor that is critical for B-cell survival and proliferation. In preclinical studies, ibrutinib bound to Bruton's tyrosine kinase with high affinity, leading to inhibition of B-cell receptor signaling, decreased B-cell activation and induction of apoptosis. In clinical studies, ibrutinib has been well-tolerated and has demonstrated profound anti-tumor activity in a variety of hematologic malignancies, most notably chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), leading to US FDA approval for relapsed CLL and MCL. Ongoing studies are evaluating ibrutinib in other types of non-Hodgkin's lymphoma, such as diffuse large B-cell lymphoma and Waldenström's macrogobulinemia, in larger Phase III studies in CLL and MCL, and in combination studies with monoclonal antibodies and chemotherapy. Future studies will combine ibrutinib with other promising novel agents currently in development in hematologic malignancies.

Pharmacological targeting of IDO-mediated tolerance for treating autoimmune disease.

PubMed

Penberthy, W Todd

2007-04-01

Cells at the maternal-fetal interface express indoleamine 2,3 dioxygenase (IDO) to consume all local tryptophan for the express purpose of starving adjacent maternal T cells of this most limiting and essential amino acid. This stops local T cell proliferation to ultimately result in the most dramatic example of immune tolerance, acceptance of the fetus. By contrast, inhibition of IDO using 1-methyl-tryptophan causes a sudden catastrophic rejection of the mammalian fetus. Immunomodulatory factors including IFNgamma, TNFalpha, IL-1, and LPS use IDO induction in responsive antigen presenting cells (APCs) also to transmit tolerogenic signals to T cells. Thus it makes sense to consider IDO induction towards tolerance for autoimmune diseases in general. Approaches to cell specific therapeutic IDO induction with NAD precursor supplementation to prevent the collateral non-T cell pathogenesis due to chronic TNFalpha-IDO activated tryptophan depletion in autoimmune diseases are reviewed. Tryptophan is an essential amino acid most immediately because it is the only precursor for the endogenous biosynthesis of nicotinamide adenine dinucleotide (NAD). Both autoimmune disease and the NAD deficiency disease pellagra occur in women at greater than twice the frequency of occurrence in men. The importance of IDO dysregulation manifest as autoimmune pellagric dementia is genetically illustrated for Nasu-Hakola Disease (or PLOSL), which is caused by a mutation in the IDO antagonizing genes TYROBP/DAP12 or TREM2. Loss of function leads to psychotic symptoms rapidly progressing to presenile dementia likely due to unchecked increases in microglial IDO expression, which depletes neurons of tryptophan causing neurodegeneration. Administration of NAD precursors rescued entire mental hospitals of dementia patients literally overnight in the 1930's and NAD precursors should help Nasu-Hakola patients as well. NAD depletion mediated by peroxynitrate PARP1 activation is one of the few established mechanisms of necrosis. Chronic elevation of TNFalpha leading to necrotic events by NAD depletion in autoimmune disease likely occurs via combination of persistent IDO activation and iNOS-peroxynitrate activation of PARP1 both of which deplete NAD. Pharmacological doses of NAD precursors repeatedly provide dramatic therapeutic benefit for rheumatoid arthritis, type 1 diabetes, multiple sclerosis, colitis, other autoimmune diseases, and schizophrenia in either the clinic or animal models. Collectively these observations support the idea that autoimmune disease may in part be considered as localized pellagra manifesting symptoms particular to the inflamed target tissues. Thus pharmacological doses of NAD precursors (nicotinic acid/niacin, nicotinamide/niacinamide, or nicotinamide riboside) should be considered as potentially essential to the therapeutic success of any IDO-inducing regimen for treating autoimmune diseases. Distinct among the NAD precursors, nicotinic acid specifically activates the g-protein coupled receptor (GPCR) GPR109a to produce the IDO-inducing tolerogenic prostaglandins PGE(2) and PGD(2). Next, PGD(2) is converted to the anti-inflammatory prostaglandin, 15d-PGJ(2). These prostaglandins exert potent anti-inflammatory activities through endogenous signaling mechanisms involving the GPCRs EP2, EP4, and DP1 along with PPARgamma respectively. Nicotinamide prevents type 1 diabetes and ameliorates multiple sclerosis in animal models, while nothing is known about the therapeutic potential of nicotinamide riboside. Alternatively the direct targeting of the non-redox NAD-dependent proteins using resveratrol to activate SIRT1 or PJ34 in order to inhibit PARP1 and prevent autoimmune pathogenesis are also given consideration.

Early life exposure to bisphenol A investigated in mouse models of airway allergy, food allergy and oral tolerance.

PubMed

Nygaard, Unni Cecilie; Vinje, Nina Eriksen; Samuelsen, Mari; Andreassen, Monica; Groeng, Else-Carin; Bølling, Anette Kocbach; Becher, Rune; Lovik, Martinus; Bodin, Johanna

2015-09-01

The impact of early life exposure to bisphenol A (BPA) through drinking water was investigated in mouse models of respiratory allergy, food allergy and oral tolerance. Balb/c mice were exposed to BPA (0, 10 or 100 μg/ml), and the offspring were intranasally exposed to the allergen ovalbumin (OVA). C3H/HeJ offspring were sensitized with the food allergen lupin by intragastric gavage, after exposure to BPA (0, 1, 10 or 100 μg/ml). In separate offspring, oral tolerance was induced by gavage of 5 mg lupin one week before entering the protocol for the food allergy induction. In the airway allergy model, BPA (100 μg/ml) caused increased eosinophil numbers in bronchoalveolar lavage fluid (BALF) and a trend of increased OVA-specific IgE levels. In the food allergy and tolerance models, BPA did not alter the clinical anaphylaxis or antibody responses, but induced alterations in splenocyte cytokines and decreased mouse mast cell protease (MMCP)-1 serum levels. In conclusion, early life exposure to BPA through drinking water modestly augmented allergic responses in a mouse model of airway allergy only at high doses, and not in mouse models for food allergy and tolerance. Thus, our data do not support that BPA promotes allergy development at exposure levels relevant for humans. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cordyceps sinensis increases hypoxia tolerance by inducing heme oxygenase-1 and metallothionein via Nrf2 activation in human lung epithelial cells.

PubMed

Singh, Mrinalini; Tulsawani, Rajkumar; Koganti, Praveen; Chauhan, Amitabh; Manickam, Manimaran; Misra, Kshipra

2013-01-01

Cordyceps sinensis, an edible mushroom growing in Himalayan regions, is widely recognized in traditional system of medicine. In the present study, we report the efficacy of Cordyceps sinensis in facilitating tolerance to hypoxia using A549 cell line as a model system. Treatment with aqueous extract of Cordyceps sinensis appreciably attenuated hypoxia induced ROS generation, oxidation of lipids and proteins and maintained antioxidant status similar to that of controls via induction of antioxidant gene HO1 (heme oxygenase-1), MT (metallothionein) and Nrf2 (nuclear factor erythroid-derived 2-like 2). In contrast, lower level of NF κ B (nuclear factor kappaB) and tumor necrosis factor- α observed which might be due to higher levels of HO1, MT and transforming growth factor- β . Further, increase in HIF1 (hypoxia inducible factor-1) and its regulated genes; erythropoietin, vascular endothelial growth factor, and glucose transporter-1 was observed. Interestingly, Cordyceps sinensis treatment under normoxia did not regulate the expression HIF1, NF κ B and their regulated genes evidencing that Cordyceps sinensis per se did not have an effect on these transcription factors. Overall, Cordyceps sinensis treatment inhibited hypoxia induced oxidative stress by maintaining higher cellular Nrf2, HIF1 and lowering NF κ B levels. These findings provide a basis for possible use of Cordyceps sinensis in tolerating hypoxia.

Cordyceps sinensis Increases Hypoxia Tolerance by Inducing Heme Oxygenase-1 and Metallothionein via Nrf2 Activation in Human Lung Epithelial Cells

PubMed Central

Manickam, Manimaran; Misra, Kshipra

2013-01-01

Cordyceps sinensis, an edible mushroom growing in Himalayan regions, is widely recognized in traditional system of medicine. In the present study, we report the efficacy of Cordyceps sinensis in facilitating tolerance to hypoxia using A549 cell line as a model system. Treatment with aqueous extract of Cordyceps sinensis appreciably attenuated hypoxia induced ROS generation, oxidation of lipids and proteins and maintained antioxidant status similar to that of controls via induction of antioxidant gene HO1 (heme oxygenase-1), MT (metallothionein) and Nrf2 (nuclear factor erythroid-derived 2-like 2). In contrast, lower level of NFκB (nuclear factor kappaB) and tumor necrosis factor-α observed which might be due to higher levels of HO1, MT and transforming growth factor-β. Further, increase in HIF1 (hypoxia inducible factor-1) and its regulated genes; erythropoietin, vascular endothelial growth factor, and glucose transporter-1 was observed. Interestingly, Cordyceps sinensis treatment under normoxia did not regulate the expression HIF1, NFκB and their regulated genes evidencing that Cordyceps sinensis per se did not have an effect on these transcription factors. Overall, Cordyceps sinensis treatment inhibited hypoxia induced oxidative stress by maintaining higher cellular Nrf2, HIF1 and lowering NFκB levels. These findings provide a basis for possible use of Cordyceps sinensis in tolerating hypoxia. PMID:24063008

Induction of MHC-mismatched Mouse Lung Allograft Acceptance with Combined Donor Bone Marrow: Lung Transplant using a 12-Hour Nonmyeloablative Conditioning Regimen

PubMed Central

Vulic, Ante; Panoskaltsis-Mortari, Angela; McDyer, John F.; Luznik, Leo

2016-01-01

Background Despite broad and intense conventional immunosuppression, long-term survival after lung transplantation lags behind that for other solid organ transplants, primarily because of allograft rejection. Therefore, new strategies to promote lung allograft acceptance are urgently needed. The purpose of the present study was to induce allograft tolerance with a protocol compatible with deceased donor organ utilization. Methods Using the MHC-mismatched mouse orthotopic lung transplant model, we investigated a conditioning regimen consisting of pretransplant T cell depletion, low dose total body irradiation and posttransplant (donor) bone marrow and splenocyte infusion followed by posttransplantation cyclophosphamide (PTTT-PTB/PTCy). Results Our results show that C57BL/6 recipients of BALB/c lung allografts undergoing this complete short-duration nonmyeloablative conditioning regimen had durable lung allograft acceptance. Mice that lacked 1 or more components of this regimen exhibited significant graft loss. Mechanistically, animals with lung allograft acceptance had established higher levels of donor chimerism, lymphocyte responses which were attenuated to donor antigens but maintained to third-party antigens, and clonal deletion of donor-reactive host Vβ T cells. Frequencies of Foxp3+ T regulatory cells were comparable in both surviving and rejected allografts implying that their perturbation was not a dominant cell-regulatory mechanism. Donor chimerism was indispensable for sustained tolerance, as evidenced by acute rejection of allografts in established chimeric recipients of PTTT-PTB/PTCy following a chimerism-ablating secondary recipient lymphocyte infusion. Conclusion Together, these data provide proof-of-concept for establishing lung allograft tolerance with tandem donor bone marrow transplantation (BMT) using a short-duration nonmyeloablative conditioning regimen and PTCy. PMID:27861294

Pro-oxidant Induced DNA Damage in Human Lymphoblastoid Cells: Homeostatic Mechanisms of Genotoxic Tolerance

PubMed Central

Seager, Anna L.

2012-01-01

Oxidative stress contributes to many disease etiologies including ageing, neurodegeneration, and cancer, partly through DNA damage induction (genotoxicity). Understanding the i nteractions of free radicals with DNA is fundamental to discern mutation risks. In genetic toxicology, regulatory authorities consider that most genotoxins exhibit a linear relationship between dose and mutagenic response. Yet, homeostatic mechanisms, including DNA repair, that allow cells to tolerate low levels of genotoxic exposure exist. Acceptance of thresholds for genotoxicity has widespread consequences in terms of understanding cancer risk and regulating human exposure to chemicals/drugs. Three pro-oxidant chemicals, hydrogen peroxide (H2O2), potassium bromate (KBrO3), and menadione, were examined for low dose-response curves in human lymphoblastoid cells. DNA repair and antioxidant capacity were assessed as possible threshold mechanisms. H2O2 and KBrO3, but not menadione, exhibited thresholded responses, containing a range of nongenotoxic low doses. Levels of the DNA glycosylase 8-oxoguanine glycosylase were unchanged in response to pro- oxidant stress. DNA repair–focused gene expression arrays reported changes in ATM and BRCA1, involved in double-strand break repair, in response to low-dose pro-oxidant exposure; however, these alterations were not substantiated at the protein level. Determination of oxidatively induced DNA damage in H2O2-treated AHH-1 cells reported accumulation of thymine glycol above the genotoxic threshold. Further, the H2O2 dose-response curve was shifted by modulating the antioxidant glutathione. Hence, observed pro- oxidant thresholds were due to protective capacities of base excision repair enzymes and antioxidants against DNA damage, highlighting the importance of homeostatic mechanisms in “genotoxic tolerance.” PMID:22539617

Anti-Interleukin-9 Antibody Increases the Effect of Allergen-Specific Immunotherapy in Murine Allergic Rhinitis.

PubMed

Shin, Ji Hyeon; Kim, Do Hyun; Kim, Boo Young; Kim, Sung Won; Hwang, Se Hwan; Lee, Joohyung; Kim, Soo Whan

2017-05-01

Interleukin (IL)-9 induces allergic responses; however, the roles of anti-IL-9 antibody in the induction of tolerance remain unclear. This study investigated the effects of anti-IL-9 antibody on oral tolerance (OT) in a mouse model of allergic rhinitis (AR). BALB/c mice were divided into 4 groups: the control, AR, OT, and OT with anti-IL-9 antibody (OT+IL9AB) groups. Ovalbumin (OVA) was used for sensitization and challenge. Mice in the OT and OT+IL9AB groups were fed OVA for immunotherapy. During immunotherapy, OT+IL9AB mice were injected with anti-IL-9 antibody. Allergic symptoms, tissue eosinophil counts, and serum OVA-specific immunoglobulin E (IgE) were measured. The mRNA expressions of cytokines and transcription factors of T cells of nasal mucosa were determined by real-time polymerase chain reaction (PCR). The protein levels of GATA3, ROR-γt, and Foxp3 in nasal mucosa were determined by Western blot. CD4⁺CD25⁺Foxp3⁺ T cells in the spleen were analyzed by flow cytometry. Administration of anti-IL-9 antibody decreased allergic symptoms, OVA-specific IgE levels, and eosinophil counts. In addition, it inhibited T-helper (Th) 2 responses, but had no effect on Th1 responses. Protein levels of ROR-γt and mRNA levels of PU.1 and ROR-γt were reduced by anti-IL-9 antibody. Anti-IL-9 antibody increased Foxp3 and IL-10 mRNA expression, Foxp3 protein, and induction of CD4⁺CD25⁺Foxp3⁺ T cells. Anti-IL-9 antibody decreased allergic inflammation through suppression of Th2 and Th17 cells. Anti-IL-9 antibody enhanced the tolerogenic effects of regulatory T cells. These results suggest that anti-IL-9 antibody might represent a potential therapeutic agent for allergen immunotherapy in patients with uncontrolled allergic airway disease. Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The Korean Academy of Pediatric Allergy and Respiratory Disease

Low doses of allergen and probiotic supplementation separately or in combination alleviate allergic reactions to cow β-lactoglobulin in mice.

PubMed

Thang, Cin L; Boye, Joyce I; Zhao, Xin

2013-02-01

Probiotic supplementation and oral tolerance induction can reduce certain types of food allergy. The objectives of this study were to investigate the allergy-reducing effects of probiotics (VSL#3) and/or oral tolerance induction via low doses of an allergen supplementation in β-lactoglobulin (BLG)-sensitized mice. Three-week-old, male BALB/c mice were divided into 6 groups (n = 8/group): sham-sensitized negative control (CTL-), BLG-sensitized positive control (CTL+), oral tolerance-induced and BLG-sensitized group (OT), probiotic-supplemented OT group (OTP), probiotic-supplemented CTL- (PRO), and probiotic-supplemented and BLG-sensitized (PROC) groups. Mice were i.p. sensitized with BLG and alum and then orally challenged with BLG. Immunological responses were assessed by monitoring hypersensitivity scores and measuring levels of BLG-specific serum Igs, total serum IgE and fecal IgA, and cytokines from serum and spleen lysates. Hypersensitivity scores were significantly lower in the PROC (2.00 ± 0.53), OT (0.75 ± 0.46), and OTP mice (1.00 ± 0.53) than in the CTL+ mice (2.63 ± 0.52) as were BLG-specific serum IgE concentrations (34.3 ± 10, 0.442 ± 0.36, 3.54 ± 3.5, and 78.5 ± 8.7 μg/L for PROC, OT, OTP, and CTL+, respectively). Our results suggest that supplementation of VSL#3 suppressed the allergic reaction mainly through increased intestinal secretary IgA (sIgA) in PROC mice, and oral tolerance offered allergen-specific protective effects to BLG-induced allergy, probably through CD4+CD25+ regulatory T cell-mediated active suppression. In OTP mice, probiotics did not induce a further reduction of hypersensitivity score compared with OT mice but may provide additional protection to unforeseen nonspecific challenges through increased intestinal sIgA.

Activation of p38 MAPK participates in brain ischemic tolerance induced by limb ischemic preconditioning by up-regulating HSP 70.

PubMed

Sun, Xiao-Cai; Xian, Xiao-Hui; Li, Wen-Bin; Li, Li; Yan, Cai-Zhen; Li, Qing-Jun; Zhang, Min

2010-08-01

This study investigates whether activation of p38 MAPK by the up-regulation of HSP 70 participates in the induction of brain ischemic tolerance by limb ischemic preconditioning (LIP). Western blot and immunohistochemical assays indicated that p38 MAPK activation occurred earlier than HSP 70 induction in the CA1 region of the hippocampus after LIP. P-p38 MAPK expression was up-regulated at 6h and reached its peak 12h after LIP, while HSP 70 expression was not significantly increased until 1 day and peaked 2 days after LIP. Neuropathological evaluation by thionin staining showed that quercetin (4 ml/kg, 50mg/kg, intraperitoneal injection), an inhibitor of HSP 70, blocked the protective effect of LIP against delayed neuronal death that is normally induced by lethal brain ischemic insult, indicating that HSP 70 participates in the induction of brain ischemic tolerance by LIP. Furthermore, SB 203580, an inhibitor of HSP 70, inhibited HSP 70 activation in the CA1 region of the hippocampus induced by LIP either with or without the presence of subsequent brain ischemic insult. Based on the above results, it can be concluded that activation of p38 MAPK participates in the brain ischemic tolerance induced by LIP at least partly by the up-regulation of HSP 70 expression. (c) 2010 Elsevier Inc. All rights reserved.

[A pharmacological study of chlorphenesin carbamate. Tolerance to chlorphenesin carbamate (author's transl)].

PubMed

Sasajima, M; Aihara, H; Akiyama, F; Tsuchida, K; Otomo, S

1977-04-01

Tolerance to chlorphenesin carbamate (CPC) was investigated from the viewpoints of action of CPC, serum free CPC concentration, the activity of UDP-glucuronyltransferase and the content of cytochrome P-450. CPC was administered once daily for 7 or 14 days. In mice, the hypnotic action of hexobarbital injected 24 hours after the last administration of CPC and the motor incoordinating action of CPC significantly decreased on the 7th day, but slightly recovered on the 14th day. Serum free CPC concentration also decreased on the 7th day, but recovered on the 14th day. A significant relationship between the motor incoordinating action of CPC and serum free CPC concentration was observed. Therefore, the recovery of CPC effect on the 14th day was considered to be due to the recovery from the induction of drug-metabolizing enzymes. On the other hand, in rats, the weekly alteration of the motor incoordinating action of CPC was similar to that observed in mice. Serum free CPC concentration on the 7th and 14th days was lower than that on the 1st day, and enzyme induction was observed during CPC administration. Notwithstanding the low level of serum free CPC concentration, the recovery of CPC effect was observed on the 14th day and such was considered to be due to habituation to the rotarod. In mice and rats, it was demonstrated that the intensity of CPC effect was dependent on serum free CPC concentration to the extent that enzyme induction played an important role in the development of tolerance. From these results, the tolerance to CPC is attributed to induction of drug-metabolizing enzymes in liver microsomes.

Stable antigen-specific T-cell hyporesponsiveness induced by tolerogenic dendritic cells from multiple sclerosis patients.

PubMed

Raϊch-Regué, Dàlia; Grau-López, Laia; Naranjo-Gómez, Mar; Ramo-Tello, Cristina; Pujol-Borrell, Ricardo; Martínez-Cáceres, Eva; Borràs, Francesc E

2012-03-01

Multiple sclerosis (MS) is a chronic demyelinating autoimmune disease of the central nervous system. Current therapies decrease the frequency of relapses and limit, to some extent, but do not prevent disease progression. Hence, new therapeutic approaches that modify the natural course of MSneed to be identified. Tolerance induction to self-antigens using monocyte-derived dendritic cells (MDDCs) is a promising therapeutic strategy in autoimmunity. In this work, we sought to generate and characterize tolerogenic MDDCs (tolDCs) from relapsing-remitting (RR) MSpatients, loaded with myelin peptides as specific antigen, with the aim of developing immunotherapeutics for MS. MDDCs were generated from both healthy-blood donors and RR-MSpatients, and MDDCmaturation was induced with a proinflammatory cytokine cocktail in the absence or presence of 1α,25-dihydroxyvitamin-D(3) , a tolerogenicity-inducing agent. tolDCs were generated from monocytes of RR-MSpatients as efficiently as from monocytes of healthy subjects. The RR-MStolDCs expressed a stable semimature phenotype and an antiinflammatory profile as compared with untreated MDDCs. Importantly, myelin peptide-loaded tolDCs induced stable antigen-specific hyporesponsiveness in myelin-reactive T cells from RR-MS patients. These results suggest that myelin peptide-loaded tolDCs may be a powerful tool for inducing myelin-specific tolerance in RR-MS patients. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Markers of tolerance development to food allergens.

PubMed

Ponce, M; Diesner, S C; Szépfalusi, Z; Eiwegger, T

2016-10-01

IgE-mediated reactions to food allergens are the most common cause of anaphylaxis in childhood. Although allergies to cow's milk, egg, or soy proteins, in contrast to peanut and tree nut allergens, resolve within the first 6 years of life in up to 60% due to natural tolerance development, this process is not well understood. At present, there is no cure or treatment for food allergy that would result in an induction of tolerance to the symptom-eliciting food. Avoidance, providing an emergency plan and education, is the standard of treatment. Oral immunotherapeutic approaches have been proven reasonable efficacy; however, they are associated with high rates of side-effects and low numbers of patients achieving tolerance. Nevertheless, mechanisms that take place during oral immunotherapy may help to understand tolerance development. On the basis of these therapeutic interventions, events like loss of basophil activation and induction of regulatory lymphocyte subsets and of blocking antibodies have been described. Their functional importance at a clinical level, however, remains to be investigated in detail. Consequently, there is eminent need to understand the process of tolerance development to food allergens and define biomarkers to develop and monitor new treatment strategies for food allergy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Induction of abiotic stress tolerance in plants by endophytic microbes.

PubMed

Lata, R; Chowdhury, S; Gond, S K; White, J F

2018-04-01

Endophytes are micro-organisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species scavengers. This review may help in the development of biotechnological applications of endophytic microbes in plant growth promotion and crop improvement under abiotic stress conditions. Increasing human populations demand more crop yield for food security while crop production is adversely affected by abiotic stresses like drought, salinity and high temperature. Development of stress tolerance in plants is a strategy to cope with the negative effects of adverse environmental conditions. Endophytes are well recognized for plant growth promotion and production of natural compounds. The property of endophytes to induce stress tolerance in plants can be applied to increase crop yields. With this review, we intend to promote application of endophytes in biotechnology and genetic engineering for the development of stress-tolerant plants. © 2018 The Society for Applied Microbiology.

Bone Marrow Cell Transfer into Fetal Circulation Can Ameliorate Genetic Skin Diseases by Providing Fibroblasts to the Skin and Inducing Immune Tolerance

PubMed Central

Chino, Takenao; Tamai, Katsuto; Yamazaki, Takehiko; Otsuru, Satoru; Kikuchi, Yasushi; Nimura, Keisuke; Endo, Masayuki; Nagai, Miki; Uitto, Jouni; Kitajima, Yasuo; Kaneda, Yasufumi

2008-01-01

Recent studies have shown that skin injury recruits bone marrow-derived fibroblasts (BMDFs) to the site of injury to accelerate tissue repair. However, whether uninjured skin can recruit BMDFs to maintain skin homeostasis remains uncertain. Here, we investigated the appearance of BMDFs in normal mouse skin after embryonic bone marrow cell transplantation (E-BMT) with green fluorescent protein-transgenic bone marrow cells (GFP-BMCs) via the vitelline vein, which traverses the uterine wall and is connected to the fetal circulation. At 12 weeks of age, mice treated with E-BMT were observed to have successful engraftment of GFP-BMCs in hematopoietic tissues accompanied by induction of immune tolerance against GFP. We then investigated BMDFs in the skin of the same mice without prior injury and found that a significant number of BMDFs, which generate matrix proteins both in vitro and in vivo, were recruited and maintained after birth. Next, we performed E-BMT in a dystrophic epidermolysis bullosa mouse model (col7a1−/−) lacking type VII collagen in the cutaneous basement membrane zone. E-BMT significantly ameliorated the severity of the dystrophic epidermolysis bullosa phenotype in neonatal mice. Type VII collagen was deposited primarily in the follicular basement membrane zone in the vicinity of the BMDFs. Thus, gene therapy using E-BMT into the fetal circulation may offer a potential treatment option to ameliorate genetic skin diseases that are characterized by fibroblast dysfunction through the introduction of immune-tolerated BMDFs. PMID:18688022

Acid Sphingomyelinase (ASM) is a Negative Regulator of Regulatory T Cell (Treg) Development.

PubMed

Zhou, Yuetao; Salker, Madhuri S; Walker, Britta; Münzer, Patrick; Borst, Oliver; Gawaz, Meinrad; Gulbins, Erich; Singh, Yogesh; Lang, Florian

2016-01-01

Regulatory T cell (Treg) is required for the maintenance of tolerance to various tissue antigens and to protect the host from autoimmune disorders. However, Treg may, indirectly, support cancer progression and bacterial infections. Therefore, a balance of Treg function is pivotal for adequate immune responses. Acid sphingomyelinase (ASM) is a rate limiting enzyme involved in the production of ceramide by breaking down sphingomyelin. Previous studies in T-cells have suggested that ASM is involved in CD28 signalling, T lymphocyte granule secretion, degranulation, and vesicle shedding similar to the formation of phosphatidylserine-exposing microparticles from glial cells. However, whether ASM affects the development of Treg has not yet been described. Splenocytes, isolated Naive T lymphocytes and cultured T cells were characterized for various immune T cell markers by flow cytometery. Cell proliferation was measured by Carboxyfluorescein succinimidyl ester (CFSE) dye, cell cycle analysis by Propidium Iodide (PI), mRNA transcripts by q-RT PCR and protein expression by Western Blotting respectively. ASM deficient mice have higher number of Treg compared with littermate control mice. In vitro induction of ASM deficient T cells in the presence of TGF-β and IL-2 lead to a significantly higher number of Foxp3+ induced Treg (iTreg) compared with control T-cells. Further, ASM deficient iTreg has less AKT (serine 473) phosphorylation and Rictor levels compared with control iTreg. Ceramide C6 led to significant reduction of iTreg in both ASM deficient and WT mice. The reduction in iTreg leads to induction of IL-1β, IL-6 and IL-17 but not IFN-γ mRNA levels. ASM is a negative regulator of natural and iTreg. © 2016 The Author(s) Published by S. Karger AG, Basel.

Lappaol F, a novel anticancer agent isolated from plant arctium Lappa L.

PubMed

Sun, Qing; Liu, Kanglun; Shen, Xiaoling; Jin, Weixin; Jiang, Lingyan; Sheikh, M Saeed; Hu, Yingjie; Huang, Ying

2014-01-01

In an effort to search for new cancer-fighting therapeutics, we identified a novel anticancer constituent, Lappaol F, from plant Arctium Lappa L. Lappaol F suppressed cancer cell growth in a time- and dose-dependent manner in human cancer cell lines of various tissue types. We found that Lappaol F induced G(1) and G(2) cell-cycle arrest, which was associated with strong induction of p21 and p27 and reduction of cyclin B1 and cyclin-dependent kinase 1 (CDK1). Depletion of p21 via genetic knockout or short hairpin RNA (shRNA) approaches significantly abrogated Lappaol F-mediated G(2) arrest and CDK1 and cyclin B1 suppression. These results suggest that p21 seems to play a crucial role in Lappaol F-mediated regulation of CDK1 and cyclin B1 and G(2) arrest. Lappaol F-mediated p21 induction was found to occur at the mRNA level and involved p21 promoter activation. Lappaol F was also found to induce cell death in several cancer cell lines and to activate caspases. In contrast with its strong growth inhibitory effects on tumor cells, Lappaol F had minimal cytotoxic effects on nontumorigenic epithelial cells tested. Importantly, our data also demonstrate that Lappaol F exhibited strong growth inhibition of xenograft tumors in nude mice. Lappaol F was well tolerated in treated animals without significant toxicity. Taken together, our results, for the first time, demonstrate that Lappaol F exhibits antitumor activity in vitro and in vivo and has strong potential to be developed as an anticancer therapeutic.

A role for MHR1, a gene required for mitochondrial genetic recombination, in the repair of damage spontaneously introduced in yeast mtDNA.

PubMed

Ling, F; Morioka, H; Ohtsuka, E; Shibata, T

2000-12-15

A nuclear recessive mutant in Saccharomyces cerevisiae, mhr1-1, is defective in mitochondrial genetic recombination at 30 degrees C and shows extensive vegetative petite induction by UV irradiation at 30 degrees C or when cultivated at a higher temperature (37 degrees C). It has been postulated that mitochondrial DNA (mtDNA) is oxidatively damaged by by-products of oxidative respiration. Since genetic recombination plays a critical role in DNA repair in various organisms, we tested the possibility that MHR1 plays a role in the repair of oxidatively damaged mtDNA using an enzyme assay. mtDNA isolated from cells grown under standard (aerobic) conditions contained a much higher level of DNA lesions compared with mtDNA isolated from anaerobically grown cells. Soon after a temperature shift from 30 to 37 degrees C the number of mtDNA lesions increased 2-fold in mhr1-1 mutant cells but not in MHR1 cells. Malonic acid, which decreased the oxidative stress in mitochondria, partially suppressed both petite induction and the temperature-induced increase in the amount of mtDNA damage in mhr1-1 cells at 37 degrees C. Thus, functional mitochondria require active MHR1, which keeps the extent of spontaneous oxidative damage in mtDNA within a tolerable level. These observations are consistent with MHR1 having a possible role in mtDNA repair.

Oncogene-like induction of cellular invasion from centrosome amplification

PubMed Central

Godinho, Susana A.; Picone, Remigio; Burute, Mithila; Dagher, Regina; Su, Ying; Leung, Cheuk T.; Polyak, Kornelia; Brugge, Joan S.; Thery, Manuel; Pellman, David

2014-01-01

Centrosome amplification has long been recognized as a feature of human tumors, however its role in tumorigenesis remains unclear1. Centrosome amplification is poorly tolerated by non-transformed cells, and, in the absence of selection, extra centrosomes are spontaneously lost2. Thus, the high frequency of centrosome amplification, particularly in more aggressive tumors3, raises the possibility that extra centrosomes could, in some contexts, confer advantageous characteristics that promote tumor progression. Using a three-dimensional model system and other approaches to culture human mammary epithelial cells, we find that centrosome amplification triggers cell invasion. This invasive behavior is similar to that induced by overexpression of the breast cancer oncogene ErbB24 and indeed enhances invasiveness triggered by ErbB2. We show that, through increased centrosomal microtubule nucleation, centrosome amplification increases Rac1 activity, which disrupts normal cell-cell adhesion and promotes invasion. These findings demonstrate that centrosome amplification, a structural alteration of the cytoskeleton, can promote features of malignant transformation. PMID:24739973

Arsenate tolerance mechanism of Oenothera odorata from a mine population involves the induction of phytochelatins in roots.

PubMed

Kim, Dae-Yeon; Park, Hyun; Lee, Sang-Hwan; Koo, Namin; Kim, Jeong-Gyu

2009-04-01

We investigated the arsenate tolerance mechanisms of Oenothera odorata by comparing two populations [i.e., one population from the mine site (MP) and the other population from an uncontaminated site (UP)] via the exposure of hydroponic solution containing arsenate (i.e., 0-50 microM). The MP plants were significantly more tolerant to arsenate than UP plants. The UP plants accumulated more As in their shoots and roots than did the MP plants. The UP plants translocated up to 21 microg g(-1) of As into shoots, whereas MP plants translocated less As (up to 4.5 microg g(-1)) to shoots over all treatments. The results of lipid peroxidation indicated that MP plants were less damaged by oxidative stress than were UP plants. Phytochelatin (PC) content correlated linearly with root As concentration in the MP (i.e., [PCs](root)=1.69x[As](root), r(2)=0.945) and UP (i.e., [PCs](root)=0.89x[As](root), r(2)=0.979) plants. This relationship means that increased PC to As ratio may be associated with increased tolerance. Our results suggest that PC induction in roots plays a critical role in As tolerance of O. odorata.

Induction of tolerance to poison ivy urushiol in the guinea pig by epicutaneous application of the structural analog 5-methyl-3-n-pentadecylcatechol.

PubMed

Stampf, J L; Benezra, C; Byers, V; Castagnoli, N

1986-05-01

Previous studies have established that epicutaneous application of 5-methyl-3-n-pentadecylcatechol (5-Me-PDC), a synthetic analog of a poison ivy urushiol component, leads to immune tolerance to 3-n-pentadecylcatechol (PDC) in mice. The induction of tolerance by 5-Me-PDC may be mediated by a protein conjugate formed via selective reaction of thiol nucleophiles present on the carrier macromolecule with the corresponding o-quinone derived from the parent catechol. In order to examine further the tolerogenic properties of 5-Me-PDC, we have extended our studies to the guinea pig, the generally accepted experimental species for the study of contact allergy. The results have established that specific immune tolerance to poison ivy urushiol is induced following 2 epicutaneous applications of the PDC analog. Furthermore, we were able to show that the treated animals remained tolerant for at least 6 weeks, a period of time comparable to that observed following the intravenous administration of the O,O-bis-acetyl derivative of PDC. The data point to the possibility of developing a therapeutically effective topical tolerogen for poison ivy contact dermatitis.

Role of abscisic acid in strigolactone-induced salt stress tolerance in arbuscular mycorrhizal Sesbania cannabina seedlings.

PubMed

Ren, Cheng-Gang; Kong, Cun-Cui; Xie, Zhi-Hong

2018-05-03

Strigolactones (SLs) are considered to be a novel class of phytohormone involved in plant defense responses. Currently, their relationships with other plant hormones, such as abscisic acid (ABA), during responses to salinity stress are largely unknown. In this study, the relationship between SL and ABA during the induction of H 2 O 2 - mediated tolerance to salt stress were studied in arbuscular mycorrhizal (AM) Sesbania cannabina seedlings. The SL levels increased after ABA treatments and decreased when ABA biosynthesis was inhibited in AM plants. Additionally, the expression levels of SL-biosynthesis genes in AM plants increased following treatments with exogenous ABA and H 2 O 2 . Furthermore, ABA-induced SL production was blocked by a pre-treatment with dimethylthiourea, which scavenges H 2 O 2 . In contrast, ABA production was unaffected by dimethylthiourea. Abscisic acid induced only partial and transient increases in the salt tolerance of TIS108 (a SL synthesis inhibitor) treated AM plants, whereas SL induced considerable and prolonged increases in salt tolerance after a pre-treatment with tungstate. These results strongly suggest that ABA is regulating the induction of salt tolerance by SL in AM S. cannabina seedlings.

Induction of lactation in the intended mother of a surrogate pregnancy: case report.

PubMed

Biervliet, F P; Maguiness, S D; Hay, D M; Killick, S R; Atkin, S L

2001-03-01

A case of a successful induction of lactation in a commissioning mother of a surrogate pregnancy is reported. Induction of lactation was achieved with oral metoclopramide which was well tolerated. Alternative methods to induce lactation are reviewed. The advantages of breast-feeding and the relative ease with which lactation can be induced after a surrogate pregnancy would suggest that this could be offered to all commissioning mothers.

Cold Shock Induction of Thermal Sensitivity in Listeria monocytogenes

PubMed Central

Miller, Arthur J.; Bayles, Darrell O.; Eblen, B. Shawn

2000-01-01

Cold shock at 0 to 15°C for 1 to 3 h increased the thermal sensitivity of Listeria monocytogenes. In a model broth system, thermal death time at 60°C was reduced by up to 45% after L. monocytogenes Scott A was cold shocked for 3 h. The duration of the cold shock affected thermal tolerance more than did the magnitude of the temperature downshift. The Z values were 8.8°C for controls and 7.7°C for cold-shocked cells. The D values of cold-shocked cells did not return to control levels after incubation for 3 h at 28°C followed by heating at 60°C. Nine L. monocytogenes strains that were cold shocked for 3 h exhibited D60 values that were reduced by 13 to 37%. The D-value reduction was greatest in cold-shocked stationary-phase cells compared to cells from cultures in either the lag or exponential phases of growth. In addition, cold-shocked cells were more likely to be inactivated by a given heat treatment than nonshocked cells, which were more likely to experience sublethal injury. The D values of chloramphenicol-treated control cells and chloramphenicol-treated cold-shocked cells were no different from those of untreated cold-shocked cells, suggesting that cold shock suppresses synthesis of proteins responsible for heat protection. In related experiments, the D values of L. monocytogenes Scott A were decreased 25% on frankfurter skins and 15% in ultra-high temperature milk if the inoculated products were first cold shocked. Induction of increased thermal sensitivity in L. monocytogenes by thermal flux shows potential to become a practical and efficacious preventative control method. PMID:11010880

Synthesis and Anticancer Activity of Epipolythiodiketopiperazine Alkaloids

PubMed Central

Boyer, Nicolas; Morrison, Karen C.; Kim, Justin; Hergenrother, Paul J.; Movassaghi, Mohammad

2013-01-01

The epipolythiodiketopiperazine (ETP) alkaloids are a highly complex class of natural products with potent anticancer activity. Herein, we report the application of a flexible and scalable synthesis, allowing the construction of dozens of ETP derivatives. The evaluation of these compounds against cancer cell lines in culture allows for the first expansive structure–activity relationship (SAR) to be defined for monomeric and dimeric ETP-containing natural products and their synthetic cognates. Many ETP derivatives demonstrate potent anticancer activity across a broad range of cancer cell lines, and kill cancer cellsviainduction of apoptosis. Several traits thatbode well for the translational potential of the ETP class of natural products includeconcise and efficient synthetic access, potent induction of apoptotic cell death, activity against a wide range of cancer types, and a broad tolerance for modifications at multiple sitesthat should facilitate small-molecule drug development, mechanistic studies, and evaluation in vivo. PMID:23914293

Biological effects of Corynebacterium parvum. IV. Adjuvant and inhibitory activities on B lymphocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howard, J.G.; Christie, G.H.; Scott, M.T.

1973-05-01

The PFC response to the thymus-independent antigen SIII (type 3 pneumococcal polysaccharide) was amplified in mice injected 4 days previously with killed Corynebacterium parvum. This adjuvant activity was demonstrable with high (2 to 50 mu g) but not low (0.1 to 0.5 mu g) doses of SIII. Induction of tolerance was unaffected. Depression of the response resulted from simultaneous injection of SIII with either C. parvum or Bordetella pertussis, while prior treatment with the latter was without effect. Responsiveness to SIII was transiently but potently suppressed in spleen cells transferred into lethally irradiated, C. parvum pretreated mice. Although C. parvummore » is an effective B cell adjuvant, other data imply that it acts indirectly on these lymphocytes. It is argued that both adjuvant and suppressive activities of C. parvum on the B cell response to SIII are most probably mediated by activated macrophages. (auth)« less

Biological effects of Corynebacterium parvum. IV. Adjuvant and inhibitory activities on B lymphocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howard, J.G.; Christie, G.H.; Scott, M.T.

1973-05-01

The PFC response to the thymus-independent antigen SIII(type 3 pneumococcal polysaccharide) was amplified in mice injected 4 days previously with killed Corynebacterium parvum. This adjuvant activity was demonstrable with high (2 to 50 mu g) but not low (0.1 to 0.5 mu g) doses of SIII. Induction of tolerance was unaffected. Depression of the response resulted from simultaneous injection of SIII with either C. parvum or Bordetella pertussis, while prior treatment with the latter was without effect. Responsiveness to SIII was transiently but potently suppressed in spleen cells transferred into lethally irradiated, C. parvum pretreated mice. Although C. parvum ismore » an effective B cell adjuvant, other data imply that it acts indirectly on these iymphocytes. It is argued that both adjuvant and suppressive activities of C. parvum on the B cell response to SIII are most probably mediated by activated macrophages. (auth)« less

Dietary Nutrients and Bioactive Substances Modulate Heat Shock Protein (HSP) Expression: A Review.

PubMed

Moura, Carolina Soares; Lollo, Pablo Christiano Barboza; Morato, Priscila Neder; Amaya-Farfan, Jaime

2018-05-28

Interest in the heat shock proteins (HSPs), as a natural physiological toolkit of living organisms, has ranged from their chaperone function in nascent proteins to the remedial role following cell stress. As part of the defence system, HSPs guarantee cell tolerance against a variety of stressors, including exercise, oxidative stress, hyper and hypothermia, hyper and hypoxia and improper diets. For the past couple of decades, research on functional foods has revealed a number of substances likely to trigger cell protection through mechanisms that involve the induction of HSP expression. This review will summarize the occurrence of the most easily inducible HSPs and describe the effects of dietary proteins, peptides, amino acids, probiotics, high-fat diets and other food-derived substances reported to induce HSP response in animals and humans studies. Future research may clarify the mechanisms and explore the usefulness of this natural alternative of defense and the modulating mechanism of each substance.

A phase I window, dose escalating and safety trial of metformin in combination with induction chemotherapy in relapsed refractory acute lymphoblastic leukemia: Metformin with induction chemotherapy of vincristine, dexamethasone, PEG-asparaginase, and doxorubicin.

PubMed

Trucco, Matteo; Barredo, Julio C; Goldberg, John; Leclerc, Gilles M; Hale, Gregory A; Gill, Jonathan; Setty, Bhuvana; Smith, Tiffany; Lush, Richard; Lee, Jae K; Reed, Damon R

2018-06-01

Acute lymphoblastic leukemia (ALL) remains a major cause of death in children. AMP-activated protein kinase (AMPK) affects the unfolded protein response (UPR), leading to increased vulnerability to endoplasmic reticulum (ER) stress in ALL cells. In vitro, metformin causes ALL cell death via AMPK-mediated inhibition of the UPR. It was evaluated whether ER stress could be induced in relapsed ALL through a phase I study investigating the safety and feasibility of metformin in combination with relapse induction chemotherapy. Metformin was administered twice daily for 28 days in addition to vincristine, dexamethasone, PEG-asparaginase and doxorubicin (VXLD). Dose escalation of metformin was evaluated using a 3+3 design. Pharmacokinetics (PK), pharmacodynamic (PD) evaluation of the AMPK and ER stress/UPR pathways, and treatment response were assessed. Fourteen patients were enrolled; all were evaluable for toxicity. The recommended phase 2 dose (RP2D) was Dose level 2, 1,000 mg/m 2 /day. A single dose-limiting toxicity (DLT), hypoglycemia with acidosis, was observed at the RP2D and two DLTs, diarrhea and acidosis, were observed at Dose Level 3. Nine patients were evaluable for response as defined by the protocol, receiving at least 85% of planned metformin doses. Five complete remissions, one partial response, and one stable disease were observed. PD evaluation showed induction of ER stress, activation of AMPK, and inhibition of the UPR. The VXLD with metformin was tolerable with a RP2D for metformin of 1,000 mg/m 2 /day and yielded responses in a heavily pretreated population. ER stress was induced and toxicities attributable to metformin occurred in all dose levels. © 2018 Wiley Periodicals, Inc.

GARP inhibits allergic airway inflammation in a humanized mouse model.

PubMed

Meyer-Martin, H; Hahn, S A; Beckert, H; Belz, C; Heinz, A; Jonuleit, H; Becker, C; Taube, C; Korn, S; Buhl, R; Reuter, S; Tuettenberg, A

2016-09-01

Regulatory T cells (Treg) represent a promising target for novel treatment strategies in patients with inflammatory/allergic diseases. A soluble derivate of the Treg surface molecule glycoprotein A repetitions predominant (sGARP) has strong anti-inflammatory and regulatory effects on human cells in vitro as well as in vivo through de novo induction of peripheral Treg. The aim of this study was to investigate the immunomodulatory function of sGARP and its possible role as a new therapeutic option in allergic diseases using a humanized mouse model. To analyze the therapeutic effects of sGARP, adult NOD/Scidγc(-/-) (NSG) mice received peripheral blood mononuclear cells (PBMC) derived from allergic patients with sensitization against birch allergen. Subsequently, allergic inflammation was induced in the presence of Treg alone or in combination with sGARP. In comparison with mice that received Treg alone, additional treatment with sGARP reduced airway hyperresponsiveness (AHR), influx of neutrophils and macrophages into the bronchoalveolar lavage (BAL), and human CD45(+) cells in the lungs. Furthermore, the numbers of mucus-producing goblet cells and inflammatory cell infiltrates were reduced. To elucidate whether the mechanism of action of sGARP involves the TGF-β receptor pathway, mice additionally received anti-TGF-β receptor II (TGF-βRII) antibodies. Blocking the signaling of TGF-β through TGF-βRII abrogated the anti-inflammatory effects of sGARP, confirming its essential role in inhibiting the allergic inflammation. Induction of peripheral tolerance via sGARP is a promising potential approach to treat allergic airway diseases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Immune tolerance induction in patients with haemophilia a and inhibitors: effectiveness and cost analysis in an European Cohort (The ITER Study).

PubMed

Rocino, A; Cortesi, P A; Scalone, L; Mantovani, L G; Crea, R; Gringeri, A

2016-01-01

Although immune tolerance induction (ITI) is considered the first choice treatment to eradicate inhibitors in haemophilia A patients, little is known about outcomes determinants and cost magnitude. A retrospective, multicentre study was conducted to assess the relationship between ITI outcome, clinical and treatment characteristics and cost of ITI treatment in haemophilia A patients. Data from 12 months before inhibitor diagnosis to 12 months after ITI completion were collected. Treatment cost was calculated in the third-party perspective and expressed as mean € per patient-month. Cox regression models were used to identify predictors of better outcome and the time taken to achieve tolerance. Seventy-one patients, aged 0.4-41 years (median: 3.8 years) at ITI start, were enrolled. Undetectable inhibitor was achieved in 84.5% of patients and inhibitor eradication with normal factor VIII (FVIII) pharmacokinetics in 74.2%. Median time to successful tolerance was 10.7 months (range 2.0-90.0 months). Peak inhibitor level on ITI was a significant predictor of ITI success. Breakthrough bleeding event incidence during ITI was associated with time to success. The mean cost of treatment for the time period between inhibitor diagnosis and ITI start was €3188 per patient-month (92.1% for bypassing agents), and €60 078 during ITI (76.8% for FVIII use in ITI). Immune tolerance induction in this patient cohort was successful in 84.5% of patients with a mean cost of €60 000 per patient-month. This high cost is dwarfed by comparison with the prospect of lifelong care of an inhibitor patient, in addition to gains in life expectancy and health-related quality of life. © 2015 John Wiley & Sons Ltd.

Induction of metallothionein in chick embryos as a mechanism of tolerance to platinum group metal exposure.

PubMed

Gagnon, Zofia E; Patel, Amit

2007-02-15

Recent data show that platinum group metals (PGMs), primarily platinum (Pt), palladium (Pd) and rhodium (Rd), from automobile catalytic converters are being deposited in the environment. We investigated the PGM neurotoxicity and tolerance mechanism by induction of metallothionein (MT) in developing chick embryos. Chick embryos were injected on the 7th and 14th days of incubation with different concentrations of Pt and mixture of Pt, Pd and Rh (PGM mix) solutions. It is documented that induction of MT by zinc (Zn+2) protects against metal and non-metal hepatotoxicity. In this study the MT induction was examined through pretreatment of the two highest Pt(IV) exposure levels with exogenous Zn2+ on the 4th and 11th days of incubation. SDS-PAGE assay and digital image system were used to identify and quantify MT in homogenized brain and liver tissues. Quantitative analysis revealed an increase of MT in the 5 ppm Pt exposure as compared to controls. The 10 ppm Pt treatment was a lethal dose for exposed embryos. There was increased mortality at the 1.0 PGM mix level. The interaction of Pt, Pd and Rh in the mixture seems to favor metal accumulation and MT induction in the liver but not the brain. Pretreatment with exogenous Zn2+ increased chick survival. These results indicate that induction of MT plays a protective role against PGM toxicity. Metal analysis using atomic absorption spectrometer in graphite furnace mode (GFAAS) revealed PGM accumulation in chick embryo liver and brain tissues proportional to exposure concentration. Our results may imply that MT has an important role as a tolerance mechanism against PGM toxicity. The presence of Pt(IV) in brain tissue suggests that the undeveloped blood-brain barrier is permeable to PGMs. This raises concerns regarding the implication of these metals on neural injury.

Subcellular Distribution and Chemical Forms of Pb in Corn: Strategies Underlying Tolerance in Pb Stress.

PubMed

Sun, Jianling; Luo, Liqiang

2018-06-22

Studying the accumulation position and forms of heavy metals (HMs) in organisms and cells is helpful to understand the transport process and detoxification mechanism. As typical HMs, lead (Pb) subcellular content, localization, and speciation of corn subcellular fractions were studied by a series of technologies, including transmission electron microscopy, inductively coupled plasma mass spectrometry, and X-ray absorption near edge structure. The results revealed that the electrodense granules of Pb were localized in the cell wall, intercellular space, and plasma membranes. About 71% Pb was localized at the cell wall and soluble fraction. In cell walls, the total amount of pyromorphite and Pb carbonate was about 80% and the remaining was Pb stearate. In the nuclear and chloroplast fraction, which demonstrated significant changes, major speciations were Pb sulfide (72%), basic Pb carbonate (16%), and Pb stearate (12%). Pb is blocked by cell walls as pyromorphite and Pb carbonate sediments and compartmentalized by vacuoles, which both play an inportant role in cell detoxification. Besides, sulfur-containing compounds form inside the cells.

Effects of ionizing radiation on the immune system with special emphasis on the interaction of dendritic and T cells.

PubMed

Manda, Katrin; Glasow, Annegret; Paape, Daniel; Hildebrandt, Guido

2012-01-01

Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.

Gene regulation network behind drought escape, avoidance and tolerance strategies in black poplar (Populus nigra L.).

PubMed

Yıldırım, Kubilay; Kaya, Zeki

2017-06-01

Drought is the major environmental problem limiting the productivity and survival of plant species. Here, previously identified three black poplar genotypes having contrasting response to drought were subjected to gradual soil water depletion in a pot trial to identify their physiological, morphological and antioxidation related adaptations. We also performed a microarray based transcriptome analyses on the leaves of genotypes by using Affymetrix poplar Genome Array containing 56,000 transcripts. Phenotypic analyses of each genotype confirmed their differential adaptations to drought that could be classified as drought escape, avoidance and tolerance. Comparative transcriptomic analysis indicated highly divergent gene expression patterns among the genotypes in response to drought and post drought re-watering (PDR). We identified 10641, 3824 and 9411 transcripts exclusively regulated in drought escape, avoidance and tolerant genotypes, respectively. The key genes involved in metabolic pathways, such as carbohydrate metabolism, photosynthesis, lipid metabolism, generation of precursor metabolites/energy, protein folding, redox homeostasis, secondary metabolic process and cell wall component biogenesis, were affected by drought stresses in the leaves of these genotypes. Transcript isoforms showed increased expression specificity in the genes coding for bark storage proteins and small heat shock proteins in drought tolerant genotype. On the other hand, drought-avoiding genotype specifically induced the transcripts annotated to the genes functional in secondary metabolite production that linked to enhanced leaf water content and growth performance under drought stress. Transcriptome profiling of drought escape genotype indicated specific regulation of the genes functional in programmed cell death and leaf senescence. Specific upregulation of GTP cyclohydrolase II and transcription factors (WRKY and ERFs) in only this genotype were associated to ROS dependent signalling pathways and gene regulation network responsible in induction of many degrading enzymes acting on cell wall carbohydrates, fatty acids and proteins under drought stress. Our findings provide new insights into the transcriptome dynamics and components of regulatory network associated with drought adaptation strategies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Tolerance and immunity in mice infected with herpes simplex virus: simultaneous induction of protective immunity and tolerance to delayed-type hypersensitivity.

PubMed

Nash, A A; Gell, P G; Wildy, P

1981-05-01

Unresponsiveness to delayed type hypersensitivity was induced in mice following an intravenous injection of herpes simplex virus. The principal tolerogens used were thymidine kinase-deficient virus mutants which grow poorly in vivo; u.v.-inactivated and to a lesser extent formalin-inactivated virus were also tolerogenic. The tolerance induced was specific for the virus type. Despite the tolerance to delayed hypersensitivity, anti-viral immunity is present as determined by the rapid inactivation of infectious virus. The mechanism of tolerance to herpes virus and the importance of these observations for the pathogenesis of viral disease is discussed.

Tolerance and immunity in mice infected with herpes simplex virus: simultaneous induction of protective immunity and tolerance to delayed-type hypersensitivity.

PubMed Central

Nash, A A; Gell, P G; Wildy, P

1981-01-01

Unresponsiveness to delayed type hypersensitivity was induced in mice following an intravenous injection of herpes simplex virus. The principal tolerogens used were thymidine kinase-deficient virus mutants which grow poorly in vivo; u.v.-inactivated and to a lesser extent formalin-inactivated virus were also tolerogenic. The tolerance induced was specific for the virus type. Despite the tolerance to delayed hypersensitivity, anti-viral immunity is present as determined by the rapid inactivation of infectious virus. The mechanism of tolerance to herpes virus and the importance of these observations for the pathogenesis of viral disease is discussed. PMID:7251047

Modulation of TCRβ surface expression during TCR revision.

PubMed

Simmons, Kalynn B; Wubeshet, Maramawit; Ames, Kristina T; McMahan, Catherine J; Hale, J Scott; Fink, Pamela J

2012-01-01

TCR revision is a tolerance mechanism by which self-reactive TCRs expressed by mature CD4(+) peripheral T cells are replaced by receptors encoded by genes generated by post-thymic DNA rearrangement. The downmodulation of surface TCR expression initiates TCR revision, and serves as a likely trigger for the induction of the recombinase machinery. We show here in a Vβ5 transgenic mouse model system that downregulation of the self-reactive transgene-encoded TCR is not maintained by transgene loss or diminished transcription or translation. The downregulation of surface TCR expression likely occurs in two stages, only one of which requires tolerogen expression. Copyright © 2011 Elsevier Inc. All rights reserved.

The major facilitator superfamily transporter Knq1p modulates boron homeostasis in Kluyveromyces lactis.

PubMed

Svrbicka, Alexandra; Toth Hervay, Nora; Gbelska, Yvetta

2016-03-01

Boron is an essential micronutrient for living cells, yet its excess causes toxicity. To date, the mechanisms of boron toxicity are poorly understood. Recently, the ScATR1 gene has been identified encoding the main boron efflux pump in Saccharomyces cerevisiae. In this study, we analyzed the ScATR1 ortholog in Kluyveromyces lactis--the KNQ1 gene, to understand whether it participates in boron stress tolerance. We found that the KNQ1 gene, encoding a permease belonging to the major facilitator superfamily, is required for K. lactis boron tolerance. Deletion of the KNQ1 gene led to boron sensitivity and its overexpression increased K. lactis boron tolerance. The KNQ1 expression was induced by boron and the intracellular boron concentration was controlled by Knq1p. The KNQ1 promoter contains two putative binding motifs for the AP-1-like transcription factor KlYap1p playing a central role in oxidative stress defense. Our results indicate that the induction of the KNQ1 expression requires the presence of KlYap1p and that Knq1p like its ortholog ScAtr1p in S. cerevisiae functions as a boron efflux pump providing boron resistance in K. lactis.

A Novel Approach to Reinstating Tolerance in Experimental Autoimmune Myasthenia Gravis Using a Targeted Fusion Protein, mCTA1-T146.

PubMed

Consonni, Alessandra; Sharma, Sapna; Schön, Karin; Lebrero-Fernández, Cristina; Rinaldi, Elena; Lycke, Nils Yngve; Baggi, Fulvio

2017-01-01

Reinstating tissue-specific tolerance has attracted much attention as a means to treat autoimmune diseases. However, despite promising results in rodent models of autoimmune diseases, no established tolerogenic therapy is clinically available yet. In the experimental autoimmune myasthenia gravis (EAMG) model several protocols have been reported that induce tolerance against the prime disease-associated antigen, the acetylcholine receptor (AChR) at the neuromuscular junction. Using the whole AChR, the extracellular part or peptides derived from the receptor, investigators have reported variable success with their treatments, though, usually relatively large amounts of antigen has been required. Hence, there is a need for better formulations and strategies to improve on the efficacy of the tolerance-inducing therapies. Here, we report on a novel targeted fusion protein carrying the immunodominant peptide from AChR, mCTA1-T146, which given intranasally in repeated microgram doses strongly suppressed induction as well as ongoing EAMG disease in mice. The results corroborate our previous findings, using the same fusion protein approach, in the collagen-induced arthritis model showing dramatic suppressive effects on Th1 and Th17 autoaggressive CD4 T cells and upregulated regulatory T cell activities with enhanced IL10 production. A suppressive gene signature with upregulated expression of mRNA for TGFβ, IL10, IL27, and Foxp3 was clearly detectable in lymph node and spleen following intranasal treatment with mCTA1-T146. Amelioration of EAMG disease was accompanied by reduced loss of muscle AChR and lower levels of anti-AChR serum antibodies. We believe this targeted highly effective fusion protein mCTA1-T146 is a promising candidate for clinical evaluation in myasthenia gravis patients.

A Novel Approach to Reinstating Tolerance in Experimental Autoimmune Myasthenia Gravis Using a Targeted Fusion Protein, mCTA1–T146

PubMed Central

Consonni, Alessandra; Sharma, Sapna; Schön, Karin; Lebrero-Fernández, Cristina; Rinaldi, Elena; Lycke, Nils Yngve; Baggi, Fulvio

2017-01-01

Reinstating tissue-specific tolerance has attracted much attention as a means to treat autoimmune diseases. However, despite promising results in rodent models of autoimmune diseases, no established tolerogenic therapy is clinically available yet. In the experimental autoimmune myasthenia gravis (EAMG) model several protocols have been reported that induce tolerance against the prime disease-associated antigen, the acetylcholine receptor (AChR) at the neuromuscular junction. Using the whole AChR, the extracellular part or peptides derived from the receptor, investigators have reported variable success with their treatments, though, usually relatively large amounts of antigen has been required. Hence, there is a need for better formulations and strategies to improve on the efficacy of the tolerance-inducing therapies. Here, we report on a novel targeted fusion protein carrying the immunodominant peptide from AChR, mCTA1–T146, which given intranasally in repeated microgram doses strongly suppressed induction as well as ongoing EAMG disease in mice. The results corroborate our previous findings, using the same fusion protein approach, in the collagen-induced arthritis model showing dramatic suppressive effects on Th1 and Th17 autoaggressive CD4 T cells and upregulated regulatory T cell activities with enhanced IL10 production. A suppressive gene signature with upregulated expression of mRNA for TGFβ, IL10, IL27, and Foxp3 was clearly detectable in lymph node and spleen following intranasal treatment with mCTA1–T146. Amelioration of EAMG disease was accompanied by reduced loss of muscle AChR and lower levels of anti-AChR serum antibodies. We believe this targeted highly effective fusion protein mCTA1–T146 is a promising candidate for clinical evaluation in myasthenia gravis patients. PMID:28959261

Aneugenicity and clastogenicity in freshwater fish Oreochromis niloticus exposed to incipient safe concentration of tannery effluent.

PubMed

Weldetinsae, Abel; Dawit, Mekibib; Getahun, Abebe; Patil, H S; Alemayehu, Esayas; Gizaw, Melaku; Abate, Moa; Abera, Daniel

2017-04-01

Conventional effluent bioassays mostly rely on overt responses or endpoints such as apical and Darwinian fitness. Beyond the empirical observation, laboratory toxicity testing needs to rely on effective detection of prognostic biomarkers such as genotoxicity. Indeed, characterization of tannery effluent requires slotting in of genotoxic responses in whole effluent toxicity testing procedures. Hence, the prime objective of the present experimental investigation is to apply the technique of biological assay as a tool of toxicity testing to evaluate the induction of micronuclei (MN) in peripheral erythrocytes, and exfoliated cells of gill and kidney of O.niloticus exposed to Maximum tolerable concentrations (MTCs) of composite Modjo tannery effluent (CMTE) and to compare the sensitivity of each cells origin to the induction of MN. After 72h of exposure, cellular aberrations were detected using MN and nuclear abnormality (NA) tests. The induction of MN was significantly higher in exposed groups (P<0.05) when compared to the control group; moreover the tissue specific MN response was in the order, gill cells>peripheral erythrocyte>kidney. Total NA was found to increase significantly (P<0.05), when compared to the non-exposed group. NA was also further ramified as blebbed (BL), bi-nucleated (BN), lobbed (LB) and notched (NT) abnormalities. The result of each endpoint measured has demonstrated that at a concentration of total chromium (0.1, 0.73 and 1.27mg/L), a perceptible amount cellular aberration was measured, further implicating somber treat of genotoxicity to fishes, if exposed to water contaminated with tannery effluent. This further highlight that conventional effluent monitoring alone cannot reveal the effects expressed at cellular and genetic levels further demanding the incorporation of effluent bioassays in risk assessment and risk management/abatement programs. Copyright © 2016. Published by Elsevier Inc.

Treatment of Myasthenia Gravis Based on Its Immunopathogenesis

PubMed Central

Kim, Jee Young; Park, Kee Duk

2011-01-01

The prognosis of myasthenia gravis (MG) has improved dramatically due to advances in critical-care medicine and symptomatic treatments. Its immunopathogenesis is fundamentally a T-cell-dependent autoimmune process resulting from loss of tolerance toward self-antigens in the thymus. Thymectomy is based on this immunological background. For MG patients who are inadequately controlled with sufficient symptomatic treatment or fail to achieve remission after thymectomy, remission is usually achieved through the addition of other immunotherapies. These immunotherapies can be classified into two groups: rapid induction and long-term maintenance. Rapid induction therapy includes intravenous immunoglobulin (IVIg) and plasma exchange (PE). These produce improvement within a few days after initiation, and so are useful for acute exacerbation including myasthenic crisis or in the perioperative period. High-dose prednisone has been more universally preferred for remission induction, but it acts more slowly than IVIg and PE, commonly only after a delay of several weeks. Slow tapering of steroids after a high-dose pulse offers a method of maintaining the state of remission. However, because of significant side effects, other immunosuppressants (ISs) are frequently added as "steroid-sparing agents". The currently available ISs exert their immunosuppressive effects by three mechanisms: 1) blocking the synthesis of DNA and RNA, 2) inhibiting T-cell activation and 3) depleting the B-cell population. In addition, newer drugs including antisense molecule, tumor necrosis factor alpha receptor blocker and complement inhibitors are currently under investigation to confirm their effectiveness. Until now, the treatment of MG has been based primarily on experience rather than gold-standard evidence from randomized controlled trials. It is hoped that well-organized studies and newer experimental trials will lead to improved treatments. PMID:22259613

Prolactin, dendritic cells, and systemic lupus erythematosus.

PubMed

Jara, Luis J; Benitez, Gamaliel; Medina, Gabriela

2008-01-01

Dendritic cells (DC) play a central role in the induction of autoimmunity in T and B cells. DC express a high level of the major histocompatibility complex that interact with the receptors on T cells. Immature DC present antigens efficiently. Prolactin (PRL) participates in DC maturation. Systemic lupus erythematosus (SLE) is characterized by a loss of tolerance to self-antigens and persistent production of autoantibodies. Serum from SLE patients induces normal monocytes to differentiate into DC in correlation with disease activity depending on the actions of interferon-alpha, immune complexes, PRL, etc. High serum PRL levels have been found in a subset of SLE patients associated with active disease and organ involvement. It is possible that PRL interacts with DC, skewing its function from antigen presentation to a proinflammatory phenotype with high interferon-alpha production. Therefore, SLE is characterized by deficiency of DC functions and abnormal PRL secretion. The relationships between PRL and DC may have a role in the pathogenesis of SLE.

What Are the Primary Limitations in B-Cell Affinity Maturation, and How Much Affinity Maturation Can We Drive with Vaccination?

PubMed Central

2017-01-01

A key goal of HIV-1 vaccine development is the induction of broadly neutralizing antibodies (bnAbs) targeted to the vulnerable regions of the HIV envelope. BnAbs develop overtime in ∼50%of HIV-1-infected individuals. However, to date, no vaccines have induced bnAbs and few or none of these vaccine-elicited HIV-1 antibodies carry the high frequencies of V(D)J mutations characteristic of bnAbs. Do the high frequencies of mutations characteristic of naturally induced bnAbs represent a fundamental barrier to the induction of bnAbs by vaccines? Recent studies suggest that high frequencies of V(D)J mutations can be achieved by serial vaccination strategies. Rather, it appears that, in the absence of HIV-1 infection, physiologic immune tolerance controls, including a germinal center process termed affinity reversion, may limit vaccine-driven bnAb development by clonal elimination or selecting for mutations incompatible with bnAb activity. PMID:28630077

Tolerance to Acetaminophen Hepatotoxicity in the Mouse Model of Autoprotection is Associated with Induction of Flavin-containing Monooxygenase-3 (FMO3) in Hepatocytes

EPA Science Inventory

Acetaminophen (APAP) pretreatment with a low hepatotoxic dose in mice results in resistance to a second, higher dose of APAP (APAP autoprotection). Recent microarray work by our group showed a drastic induction of liver flavin containing monooxygenase-3 (Fmo3) mRNA expression in...

Whole exome sequencing identifies novel genes for fetal hemoglobin response to hydroxyurea in children with sickle cell anemia.

PubMed

Sheehan, Vivien A; Crosby, Jacy R; Sabo, Aniko; Mortier, Nicole A; Howard, Thad A; Muzny, Donna M; Dugan-Perez, Shannon; Aygun, Banu; Nottage, Kerri A; Boerwinkle, Eric; Gibbs, Richard A; Ware, Russell E; Flanagan, Jonathan M

2014-01-01

Hydroxyurea has proven efficacy in children and adults with sickle cell anemia (SCA), but with considerable inter-individual variability in the amount of fetal hemoglobin (HbF) produced. Sibling and twin studies indicate that some of that drug response variation is heritable. To test the hypothesis that genetic modifiers influence pharmacological induction of HbF, we investigated phenotype-genotype associations using whole exome sequencing of children with SCA treated prospectively with hydroxyurea to maximum tolerated dose (MTD). We analyzed 171 unrelated patients enrolled in two prospective clinical trials, all treated with dose escalation to MTD. We examined two MTD drug response phenotypes: HbF (final %HbF minus baseline %HbF), and final %HbF. Analyzing individual genetic variants, we identified multiple low frequency and common variants associated with HbF induction by hydroxyurea. A validation cohort of 130 pediatric sickle cell patients treated to MTD with hydroxyurea was genotyped for 13 non-synonymous variants with the strongest association with HbF response to hydroxyurea in the discovery cohort. A coding variant in Spalt-like transcription factor, or SALL2, was associated with higher final HbF in this second independent replication sample and SALL2 represents an outstanding novel candidate gene for further investigation. These findings may help focus future functional studies and provide new insights into the pharmacological HbF upregulation by hydroxyurea in patients with SCA.

Central memory CD8+ T lymphocytes mediate lung allograft acceptance

PubMed Central

Krupnick, Alexander Sasha; Lin, Xue; Li, Wenjun; Higashikubo, Ryuiji; Zinselmeyer, Bernd H.; Hartzler, Hollyce; Toth, Kelsey; Ritter, Jon H.; Berezin, Mikhail Y.; Wang, Steven T.; Miller, Mark J.; Gelman, Andrew E.; Kreisel, Daniel

2014-01-01

Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade–mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44hiCD62LhiCCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. Intravital 2-photon imaging revealed that CCR7 expression on CD8+ T cells was critical for formation of stable synapses with antigen-presenting cells, resulting in IFN-γ production, which induced NO and downregulated alloimmune responses. Thus, we describe a critical role for CD8+ central memory T cells in lung allograft acceptance and highlight the need for tailored approaches for tolerance induction in the lung. PMID:24569377

Expression of CD markers' in immune thrombocytopenic purpura: prognostic approaches.

PubMed

Behzad, Masumeh Maleki; Asnafi, Ali Amin; Jaseb, Kaveh; Jalali Far, Mohammad Ali; Saki, Najmaldin

2017-12-01

Immune Thrombocytopenic Purpura (ITP) is a common autoimmune bleeding disorder characterized by a reduction in peripheral blood platelet counts. In this disease, autoantibodies (Auto-Abs) are produced against platelet GPIIb/GPIIIa by B cells, which require interaction with T cells. In this review, the importance of B and T lymphocytes in ITP prognosis has been studied. Relevant literature was identified by a PubMed search (1990-2016) of English-language papers using the terms B and T lymphocyte, platelet, CD markers and immune thrombocytopenic purpura. T and B lymphocytes are the main immune cells in the body. Defective function causes disrupted balance of different subgroups of lymphocytes, and abnormal expression of surface markers of these cells results in self-tolerance dysfunction, as well as induction of Auto-Abs against platelet glycoproteins (PG). Given the role of B and T cells in production of autoantibodies against PG, it can be stated that the detection of changes in CD markers' expression in these cells can be a good approach for assessing prognosis in ITP patients. © 2017 APMIS. Published by John Wiley & Sons Ltd.

A half millimeter thick coplanar flexible battery with wireless recharging capability.

PubMed

Kim, Joo-Seong; Ko, Dongah; Yoo, Dong-Joo; Jung, Dae Soo; Yavuz, Cafer T; Kim, Nam-In; Choi, In-Suk; Song, Jae Yong; Choi, Jang Wook

2015-04-08

Most of the existing flexible lithium ion batteries (LIBs) adopt the conventional cofacial cell configuration where anode, separator, and cathode are sequentially stacked and so have difficulty in the integration with emerging thin LIB applications, such as smart cards and medical patches. In order to overcome this shortcoming, herein, we report a coplanar cell structure in which anodes and cathodes are interdigitatedly positioned on the same plane. The coplanar electrode design brings advantages of enhanced bending tolerance and capability of increasing the cell voltage by in series-connection of multiple single-cells in addition to its suitability for the thickness reduction. On the basis of these structural benefits, we develop a coplanar flexible LIB that delivers 7.4 V with an entire cell thickness below 0.5 mm while preserving stable electrochemical performance throughout 5000 (un)bending cycles (bending radius = 5 mm). Also, even the pouch case serves as barriers between anodes and cathodes to prevent Li dendrite growth and short-circuit formation while saving the thickness. Furthermore, for convenient practical use wireless charging via inductive electromagnetic energy transfer and solar cell integration is demonstrated.

Successful liver allografts in mice by combination with allogeneic bone marrow transplantation.

PubMed Central

Nakamura, T; Good, R A; Yasumizu, R; Inoue, S; Oo, M M; Hamashima, Y; Ikehara, S

1986-01-01

Successful liver allografts were established by combination with allogeneic bone marrow transplantation. When liver tissue of BALB/c (H-2d) or C57BL/6J (H-2b) mice was minced and grafted under the kidney capsules of C3H/HeN (H-2k) mice, it was rejected. However, when C3H/HeN mice were irradiated and reconstituted with T-cell-depleted BALB/c or BALB/c nu/nu bone marrow cells, or with fetal liver cells of BALB/c mice, they accepted both donor (stem-cell)-type (BALB/c) and host (thymus)-type (C3H/HeN) liver tissue. Assays for both mixed-lymphocyte reaction and induction of cytotoxic T lymphocytes revealed that the newly developed T cells were tolerant of both donor (stem-cell)-type and host (thymus)-type major histocompatibility complex determinants. We propose that liver allografts combined with bone marrow transplantation should be considered as a viable therapy for patients with liver disease such as liver cirrhosis and hepatoma. Images PMID:3520575

Naive B cells generate regulatory T cells in the presence of a mature immunologic synapse.

PubMed

Reichardt, Peter; Dornbach, Bastian; Rong, Song; Beissert, Stefan; Gueler, Faikah; Loser, Karin; Gunzer, Matthias

2007-09-01

Naive B cells are ineffective antigen-presenting cells and are considered unable to activate naive T cells. However, antigen-specific contact of these cells leads to stable cell pairs that remain associated over hours in vivo. The physiologic role of such pairs has not been evaluated. We show here that antigen-specific conjugates between naive B cells and naive T cells display a mature immunologic synapse in the contact zone that is absent in T-cell-dendritic-cell (DC) pairs. B cells induce substantial proliferation but, contrary to DCs, no loss of L-selectin in T cells. Surprisingly, while DC-triggered T cells develop into normal effector cells, B-cell stimulation over 72 hours induces regulatory T cells inhibiting priming of fresh T cells in a contact-dependent manner in vitro. In vivo, the regulatory T cells home to lymph nodes where they potently suppress immune responses such as in cutaneous hypersensitivity and ectopic allogeneic heart transplant rejection. Our finding might help to explain old observations on tolerance induction by B cells, identify the mature immunologic synapse as a central functional module of this process, and suggest the use of naive B-cell-primed regulatory T cells, "bTregs," as a useful approach for therapeutic intervention in adverse adaptive immune responses.

Bim is required for T-cell allogeneic responses and graft-versus-host disease in vivo

PubMed Central

Yu, Yu; Yu, Jing; Iclozan, Cristina; Kaosaard, Kane; Anasetti, Claudio; Yu, Xue-Zhong

2012-01-01

Bim, a BH3-only Bcl-2-family protein, is essential for T-cell negative selection in the thymus as well as for the death of activated T cells in the periphery. The role of Bim has been extensively studied in T-cell responses to self-antigens and viral infections. Recent findings on Bim in autoimmunity triggered our interest in investigating whether Bim may play a role in another disease with inflammatory symptoms as graft-versus-host disease (GVHD). Here we report that Bim is required for optimal T-cell responses to alloantigens in vivo and for the development of GVHD. Using murine models of allogeneic bone marrow transplantation (BMT), we found that donor T cells deficient for Bim are impaired in the induction of GVHD primarily due to a significant defect in T cell activation and expansion in vivo. Upon TCR engagement, Bim-/- T cells exhibited selective defects in CD69 expression and phosphorylation of PLCγ1. Our studies uncover a novel aspect of Bim function in T-cell activation with important implications in understanding the mechanisms of T-cell activation and tolerance under allogeneic transplantation. PMID:22432091

A WRKY transcription factor participates in dehydration tolerance in Boea hygrometrica by binding to the W-box elements of the galactinol synthase (BhGolS1) promoter.

PubMed

Wang, Zhi; Zhu, Yan; Wang, Lili; Liu, Xia; Liu, Yongxiu; Phillips, Jonathan; Deng, Xin

2009-11-01

Accumulation of compatible osmolytes, such as soluble sugars, in plants is an important osmoprotective mechanism. Sugars play a role in osmotic adjustment and are associated with stabilization of proteins and cell structures, reactive oxygen species scavenging, signaling functions or induction of adaptive pathways. Galactinol is the galactosyl donor for the synthesis of raffinose family oligosaccharides (RFOs) and its synthesis by galactinol synthase (GolS) is the first committed step of the RFOs biosynthetic pathway. GolS genes are induced by a variety of stresses in both stress-sensitive and tolerant-plant species; however, the mechanism of transcriptional regulation is not fully established. In this paper, we characterized a GolS gene (BhGolS1) that was dehydration and ABA-inducible in the resurrection plant Boea hygrometrica and conferred dehydration tolerance in a transgenic tobacco system. Four W-box cis-elements were identified in the BhGolS1 promoter and shown to be bound by an early dehydration and ABA-inducible WRKY gene (BhWRKY1). These data suggest a mechanism where BhWRKY1 is likely to function in an ABA-dependent signal pathway to regulate BhGolS1 expression, which leads to the accumulation of RFOs in desiccation-tolerant B. hygrometrica leaves.

Chronic ethanol consumption inhibits glucokinase transcriptional activity by Atf3 and triggers metabolic syndrome in vivo.

PubMed

Kim, Ji Yeon; Hwang, Joo-Yeon; Lee, Dae Yeon; Song, Eun Hyun; Park, Keon Jae; Kim, Gyu Hee; Jeong, Eun Ae; Lee, Yoo Jeong; Go, Min Jin; Kim, Dae Jin; Lee, Seong Su; Kim, Bong-Jo; Song, Jihyun; Roh, Gu Seob; Gao, Bin; Kim, Won-Ho

2014-09-26

Chronic ethanol consumption induces pancreatic β-cell dysfunction through glucokinase (Gck) nitration and down-regulation, leading to impaired glucose tolerance and insulin resistance, but the underlying mechanism remains largely unknown. Here, we demonstrate that Gck gene expression and promoter activity in pancreatic β-cells were suppressed by chronic ethanol exposure in vivo and in vitro, whereas expression of activating transcription factor 3 (Atf3) and its binding to the putative Atf/Creb site (from -287 to -158 bp) on the Gck promoter were up-regulated. Furthermore, in vitro ethanol-induced Atf3 inhibited the positive effect of Pdx-1 on Gck transcriptional regulation, enhanced recruitment of Hdac1/2 and histone H3 deacetylation, and subsequently augmented the interaction of Hdac1/Pdx-1 on the Gck promoter, which were diminished by Atf3 siRNA. In vivo Atf3-silencing reversed ethanol-mediated Gck down-regulation and β-cell dysfunction, followed by the amelioration of impaired glucose tolerance and insulin resistance. Together, we identified that ethanol-induced Atf3 fosters β-cell dysfunction via Gck down-regulation and that its loss ameliorates metabolic syndrome and could be a potential therapeutic target in treating type 2 diabetes. The Atf3 gene is associated with the induction of type 2 diabetes and alcohol consumption-induced metabolic impairment and thus may be the major negative regulator for glucose homeostasis. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Upregulation of Hsp72 mediates anoxia/reoxygenation neuroprotection in the freshwater turtle via modulation of ROS.

PubMed

Kesaraju, Shailaja; Nayak, Gauri; Prentice, Howard M; Milton, Sarah L

2014-09-25

The neuroprotective role of Hsp72 has been demonstrated in several ischemic/stroke models to occur primarily through mediation of apoptotic pathways, and a number of heat shock proteins are upregulated in animal models capable of extended anoxic survival. In the present study, we investigated the role of Hsp72 on cell death and apoptotic regulators in one anoxia tolerant model system, the freshwater turtle Trachemys scripta. Since Hsp72 is known to regulate apoptosis through interactions with Bcl-2, we manipulated the levels of Hsp72 and Bcl-2 with siRNA in neuronally enriched primary cell cultures and examined downstream effects. The knockdown of either Hsp72 or Bcl-2 induced cell death during anoxia and reoxygenation. Knockdown of Bcl-2 resulted in increases in apoptotic markers and increased ROS levels 2-fold. However, significant knockdown of Hsp72 did not have any effect on the expression of key mitochondrial apoptotic regulators such as Cytochrome c and caspase-3. Hsp72 knockdown however significantly increased apoptosis inducing factor in both anoxia and reoxygenation and resulted in a six-fold induction of hydrogen peroxide levels. These findings suggest that the neuroprotection offered by Hsp72 in the anoxia/reoxygenation tolerant turtle is through the mediation of ROS levels and not through modulation of caspase-dependent pathways. Copyright © 2014 Elsevier B.V. All rights reserved.

Immunological mechanisms to establish embryo tolerance in early bovine pregnancy.

PubMed

Groebner, A E; Schulke, K; Schefold, J C; Fusch, G; Sinowatz, F; Reichenbach, H D; Wolf, E; Meyer, H H D; Ulbrich, S E

2011-01-01

A well-balanced immunological interaction between mother and the semi-allogenic embryo is of particular importance. The objective of the present study was to analyse mechanisms of immune tolerance in bovine pregnancy during peri-implantation. Simmental heifers inseminated with either cryopreserved spermatozoa or seminal plasma were killed 12, 15 or 18 days after oestrus. Uteri were flushed for the recovery of conceptuses and the ipsilateral intercaruncular endometrium was sampled for gene expression analysis. Indoleamine 2,3-dioxygenase (IDO) mRNA, coding for the initial enzyme of the kynurenine pathway, was 18-fold (P < 0.001) more abundant in the endometrium of Day 18 pregnant v. non-pregnant animals. Tandem mass spectrometry revealed a decrease of endometrial l-tryptophan (P = 0.0008), but an increase of l-kynurenine concentration (P = 0.005) from Day 12 to Day 18, suggesting increasing IDO activity (P < 0.03). An in vitro coculture model of endometrial cells showed an induction of IDO expression following interferon-τ exposure primarily in stroma cells, which was confirmed by in situ hybridisation localising IDO mRNA mainly in deep stroma cells. Immunohistochemical analysis revealed fewer CD45-positive leucocytes in the zona basalis of pregnant animals. Elevated IDO activity may reduce the presence of leucocytes in the pregnant endometrium, providing a possible mechanism for protecting the semi-allogenic conceptus from maternal rejection.

Cytokinin response factor 4 (CRF4) is induced by cold and involved in freezing tolerance.

PubMed

Zwack, Paul J; Compton, Margaret A; Adams, Cami I; Rashotte, Aaron M

2016-03-01

Cytokinin response factor 4 (CRF4) shows a short-term induction by cold (4 °C) that appears to play a role in non-acclimated freezing tolerance as seen in mutant and overexpression lines. Responses to abiotic stresses, such as cold stress, are critical to plant growth and optimal production. Examination of Arabidopsis cytokinin response factors (CRFs) showed transcriptional induction after exposure to cold (4 °C). In particular, CRF4 was strongly induced in both root and shoot tissues. As CRF4 is one of several CRFs not transcriptionally regulated by cytokinin, we further investigated its response to cold. Peak CRF4 induction occurred 6 h post cold exposure, after which expression was maintained at moderately elevated levels during extended cold and subsequent treatment recovery. Examination of CRF4 mutant and overexpression lines under standard (non-cold) conditions revealed little difference from WT. One exception was a small, but significant increase in primary root growth of overexpression plants (CRF4OX). Under cold conditions, the only phenotype observed was a reduction in the rate of germination of CRF4OX seeds. The pattern of CRF4 expression along with the lack of strong phenotype at 4 °C led us to hypothesize that cold induction of CRF4 could play a role in short-term cold acclimation leading to increased freeze tolerance. Examination of CRF4OX and crf4 plants exposed to freezing temperatures revealed mutants lacking expression of CRF4 were more sensitive to freezing, while CRF4OXs with increased levels CRF4 levels were more tolerant. Altered transcript expression of CBF and COR15a cold signaling pathway genes in crf4 mutant and overexpression lines suggest that CRF4 may be potentially connected to this pathway. Overall this indicates that CRF4 plays an important role in both cold response and freezing stress.

Maintenance of cytosolic calcium is crucial to extend l-arginine therapeutic benefits during continuous dosing.

PubMed

Mohan, Srinidi; Harding, Lisa

2016-10-01

The therapeutic benefits associated with short-term l-arginine supplementation are lost during continuous dosing. AMP-activated protein kinase (AMPK) functional modulation has been correlated with l-arginine therapeutic effectiveness, and with tolerance development during continuous supplementation. However, the metabolic link that is responsible for AMPK functional modulation during continuous l-arginine exposure is currently not known. To explore this, we incubated HUVECs for 7 days with 100 μmol/L l-arginine, in the presence or absence of other agents; and monitored their effects for eNOS function, and on tolerance sparing effects (viz, cellular glucose accumulation, and oxidative stress). HUVEC co-incubation with 100 μmol/L l-arginine and ≤1200 mg/mL calcium (Ca 2+ ) for 7 days avoided tolerance development, with an at least 1-fold increase in the eNOS and AMPK functional activity; and an 1-fold increase in overall cellular glucose uptake. The overall cellular cytosolic Ca 2+ was below 200 nmol/L, with no change in cellular glucose and superoxide/peroxynitrite (O 2 •- /ONOO - ) level from control. However, tolerance sparing effects of at least 70% decrease in eNOS and AMPK functional response, with an 1-fold reduction in glucose uptake, and at least 2-fold increase in O 2 •- /ONOO - were observed in cells exposed for 7 days to 100 μmol/L l-arginine at Ca 2+ co-incubation concentration of >1200 mg/mL. The >1200 mg/mL Ca2+ co-incubation condition, also improved the overall cellular Ca 2+ to >200 nmol/L. Similar tolerance response was observed in cells co-treated with 100 μmol/L l-arginine and ≤1200 mg/mL Ca 2+ in the presence of Ca 2+ influx inhibitor (20 μmol/L 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra acetic acid), or eNOS activity inhibitor (30 μmol/L l-N G -nitroarginine methyl ester). No tolerance response was seen in cells incubated for 7 days with 100 μmol/L l-arginine and ≤1200 mg/mL Ca 2+ ; even in the presence of the inhibitor for cellular glucose induction (30 μmol/L 5-chloro-2-(n-(2,5-dichlorobenzenesulfonamide))-benzoxazole). The present study thus provides the first definitive evidence that shows the need to maintain cytosolic Ca 2+ within a threshold limit of less than 200 nmol/L to extend l-arginine therapeutic efficacy during continuous dosing, without any potential tolerance development. Copyright © 2016 Elsevier Inc. All rights reserved.

Human epidermal langerhans cells express the immunoregulatory enzyme indoleamine 2,3-dioxygenase.

PubMed

von Bubnoff, Dagmar; Bausinger, Huguette; Matz, Heike; Koch, Susanne; Häcker, Georg; Takikawa, Osamu; Bieber, Thomas; Hanau, Daniel; de la Salle, Henri

2004-08-01

Langerhans cells (LC) are a special subset of dendritic cells integrating cutaneous immunity. The study of LC function is of major interest not only for efforts of vaccine design and immunotherapy but also for gaining an insight into the pathogenesis of immune-mediated cutaneous diseases and neoplasias. Recently, defined antigen-presenting cells were described that express indoleamine 2,3-dioxygenase (IDO) and inhibit T cell proliferation in vitro and in vivo. Here, we show that stimulation with interferon-gamma (IFN-gamma) induces the expression of functionally active IDO in highly purified human epidermal LC. The induction of IDO after stimulation of LC with IFN-gamma seems to follow a defined kinetic with rapid upregulation followed by a downregulation after about 24 h of culture. Accordingly, proliferation of T cells induced by anti-CD3 antibodies was modulated by supernatants of IFN-gamma-activated human epidermal LC. Importantly, downregulation of T cell proliferation by supernatants of 24 h IFN-gamma-activated LC was prevented by inhibition of IDO. These results indicate that LC not only have the capacity to stimulate but also to inhibit T cells, and suggest that LC possess an immunoregulatory function in promoting T cell tolerance by production of IDO.

Tumor exosomes block dendritic cells maturation to decrease the T cell immune response.

PubMed

Ning, Yongling; Shen, Kai; Wu, Qiyong; Sun, Xiao; Bai, Yu; Xie, Yewen; Pan, Jie; Qi, Chunjian

2018-07-01

Tumors can induce the generation and accumulation of immunosuppression in a tumor microenvironment, contributing to the tumor's escape from immunological surveillance. Although tumor antigen-pulsed dendritic cell can improve anti-tumor immune responses, tumor associated regulatory dendritic cells are involved in the induction of immune tolerance. The current study sought to investigate whether exosomes produced by tumor cells had any effect on DCs in immune suppression. In this study, we examined the effect of tumor exosomes on DCs and found that exosomes from LLC Lewis lung carcinoma or 4T1 breast cancer cell blocked the differentiation of myeloid precursor cells into CD11c + DCs and induced cell apoptosis. Tumor exosome treatment inhibited the maturation and migration of DCs and promoted the immune suppression of DCs. The treatment of tumor exosomes drastically decreased CD4 + IFN-γ + Th1 differentiation but increased the rates of regulatory T (Treg) cells. The immunosuppressive ability of tumor exosome-treated DCs were partially restored with PD-L1 blockage. These data suggested that PD-L1 played a role in tumor exosome-induced DC-associated immune suppression. Copyright © 2018 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

A novel therapeutic hepatitis B vaccine induces cellular and humoral immune responses and breaks tolerance in hepatitis B virus (HBV) transgenic mice.

PubMed

Buchmann, Pascale; Dembek, Claudia; Kuklick, Larissa; Jäger, Clemens; Tedjokusumo, Raindy; von Freyend, Miriam John; Drebber, Uta; Janowicz, Zbigniew; Melber, Karl; Protzer, Ulrike

2013-02-06

Therapeutic vaccines are currently being developed for chronic hepatitis B and C. As an alternative to long-term antiviral treatment or to support only partially effective therapy, they should activate the patient's immune system effectively to fight and finally control the virus. A paradigm of therapeutic vaccination is the potent induction of T-cell responses against key viral antigens - besides activation of a humoral immune response. We have evaluated the potential of a novel vaccine formulation comprising particulate hepatitis B surface (HBsAg) and core antigen (HBcAg), and the saponin-based ISCOMATRIX™ adjuvant for its ability to stimulate T and B cell responses in C57BL/6 mice and its ability to break tolerance in syngeneic HBV transgenic (HBVtg) mice. In C57BL/6 mice, the vaccine induced multifunctional HBsAg- and HBcAg-specific CD8+ T cells detected by staining for IFNγ, TNFα and IL-2, as well as high antibody titers against both antigens. Vaccination of HBVtg animals induced potent HBsAg- and HBcAg-specific CD8+ T-cell responses in spleens and HBcAg-specific CD8+ T-cell responses in livers as well as anti-HBs seroconversion two weeks post injection. Vaccination further reduced HBcAg expression in livers of HBVtg mice without causing liver damage. In summary, this study demonstrates therapeutic efficacy of a novel vaccine formulation in a mouse model of immunotolerant, chronic HBV infection. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quantitative iTRAQ LC-MS/MS proteomics reveals metabolic responses to biofuel ethanol in cyanobacterial Synechocystis sp. PCC 6803.

PubMed

Qiao, Jianjun; Wang, Jiangxin; Chen, Lei; Tian, Xiaoxu; Huang, Siqiang; Ren, Xiaoyue; Zhang, Weiwen

2012-11-02

Recent progress in metabolic engineering has led to autotrophic production of ethanol in various cyanobacterial hosts. However, cyanobacteria are known to be sensitive to ethanol, which restricts further efforts to increase ethanol production levels in these renewable host systems. To understand the mechanisms of ethanol tolerance so that engineering more robust cyanobacterial hosts can be possible, in this study, the responses of model cyanobacterial Synechocystis sp. PCC 6803 to ethanol were determined using a quantitative proteomics approach with iTRAQ LC-MS/MS technologies. The resulting high-quality proteomic data set consisted of 24,887 unique peptides corresponding to 1509 identified proteins, a coverage of approximately 42% of the predicted proteins in the Synechocystis genome. Using a cutoff of 1.5-fold change and a p-value less than 0.05, 135 and 293 unique proteins with differential abundance levels were identified between control and ethanol-treated samples at 24 and 48 h, respectively. Functional analysis showed that the Synechocystis cells employed a combination of induced common stress response, modifications of cell membrane and envelope, and induction of multiple transporters and cell mobility-related proteins as protection mechanisms against ethanol toxicity. Interestingly, our proteomic analysis revealed that proteins related to multiple aspects of photosynthesis were up-regulated in the ethanol-treated Synechocystis cells, consistent with increased chlorophyll a concentration in the cells upon ethanol exposure. The study provided the first comprehensive view of the complicated molecular mechanisms against ethanol stress and also provided a list of potential gene targets for further engineering ethanol tolerance in Synechocystis PCC 6803.

Melatonin induction and its role in high light stress tolerance in Arabidopsis thaliana.

PubMed

Lee, Hyoung Yool; Back, Kyoungwhan

2018-05-16

In plants, melatonin is a potent bioactive molecule involved in the response against various biotic and abiotic stresses. However, little is known of its defensive role against high light (HL) stress. In this study, we found that melatonin was transiently induced in response to HL stress in Arabidopsis thaliana with a simultaneous increase in the expression of melatonin biosynthetic genes, including serotonin N-acetyltransferase1 (SNAT1). Transient induction of melatonin was also observed in the flu mutant, a singlet oxygen ( 1 O 2 )-producing mutant, upon light exposure, suggestive of melatonin induction by chloroplastidic 1 O 2 against HL stress. An Arabidopsis snat1 mutant was devoid of melatonin induction upon HL stress, resulting in high susceptibility to HL stress. Exogenous melatonin treatment mitigated damage caused by HL stress in the snat1 mutant by reducing O 2 - production and increasing the expression of various ROS-responsive genes. In analogy, an Arabidopsis SNAT1-overexpressing line showed increased tolerance of HL stress concomitant with a reduction in malondialdehyde and ion leakage. A complementation line expressing an Arabidopsis SNAT1 genomic fragment in the snat1 mutant completely restored HL stress susceptibility in the snat1 mutant to levels comparable to that of wild-type Col-0 plants. The results of the analysis of several Arabidopsis genetic lines reveal for the first time at the genetic level that melatonin is involved in conferring HL stress tolerance in plants. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Adaptive responses of Bacillus cereus ATCC14579 cells upon exposure to acid conditions involve ATPase activity to maintain their internal pH

PubMed Central

Senouci-Rezkallah, Khadidja; Jobin, Michel P; Schmitt, Philippe

2015-01-01

This study examined the involvement of ATPase activity in the acid tolerance response (ATR) of Bacillus cereus ATCC14579 strain. In the current work, B. cereus cells were grown in anaerobic chemostat culture at external pH (pHe) 7.0 or 5.5 and at a growth rate of 0.2 h−1. Population reduction and internal pH (pHi) after acid shock at pH 4.0 was examined either with or without ATPase inhibitor N,N’-dicyclohexylcarbodiimide (DCCD) and ionophores valinomycin and nigericin. Population reduction after acid shock at pH 4.0 was strongly limited in cells grown at pH 5.5 (acid-adapted cells) compared with cells grown at pH 7.0 (unadapted cells), indicating that B. cereus cells grown at low pHe were able to induce a significant ATR and Exercise-induced increase in ATPase activity. However, DCCD and ionophores had a negative effect on the ability of B. cereus cells to survive and maintain their pHi during acid shock. When acid shock was achieved after DCCD treatment, pHi was markedly dropped in unadapted and acid-adapted cells. The ATPase activity was also significantly inhibited by DCCD and ionophores in acid-adapted cells. Furthermore, transcriptional analysis revealed that atpB (ATP beta chain) transcripts was increased in acid-adapted cells compared to unadapted cells before and after acid shock. Our data demonstrate that B. cereus is able to induce an ATR during growth at low pH. These adaptations depend on the ATPase activity induction and pHi homeostasis. Our data demonstrate that the ATPase enzyme can be implicated in the cytoplasmic pH regulation and in acid tolerance of B. cereus acid-adapted cells. PMID:25740257

Cytokines affecting CD4+T regulatory cells in transplant tolerance. II. Interferon gamma (IFN-γ) promotes survival of alloantigen-specific CD4+T regulatory cells.

PubMed

Nomura, Masaru; Hodgkinson, Suzanne J; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine; Plain, Karren M; Boyd, Rochelle; Hall, Bruce M

2017-06-01

CD4 + T cells that transfer alloantigen-specific transplant tolerance are short lived in culture unless stimulated with specific-donor alloantigen and lymphocyte derived cytokines. Here, we examined if IFN-γ maintained survival of tolerance transferring CD4 + T cells. Alloantigen-specific transplant tolerance was induced in DA rats with heterotopic adult PVG heart allografts by a short course of immunosuppression and these grafts functioned for >100days with no further immunosuppression. In previous studies, we found the CD4 + T cells from tolerant rats that transfer tolerance to an irradiated DA host grafted with a PVG heart, lose their tolerance transferring ability after 3days of culture, either with or without donor alloantigen, and effect rejection of specific-donor grafts. If cultures with specific-donor alloantigen are supplemented by supernatant from ConA activated lymphocytes the tolerance transferring cells survive, suggesting these cells depend on cytokines for their survival. In this study, we found addition of rIFN-γ to MLC with specific-donor alloantigen maintained the capacity of tolerant CD4 + T cells to transfer alloantigen-specific tolerance and their ability to suppress PVG allograft rejection mediated by co-administered naïve CD4 + T cells. IFN-γ suppressed the in vitro proliferation of tolerant CD4 + T cells. Tolerant CD4 + CD25 + T cells did not proliferate in MLC to PVG stimulator cells with no cytokine added, but did when IFN-γ was present. IFN-γ did not alter proliferation of tolerant CD4 + CD25 + T cells to third-party Lewis. Tolerant CD4 + CD25 + T cells' expression of IFN-γ receptor (IFNGR) was maintained in culture when IFN-γ was present. This study suggested that IFN-γ maintained tolerance mediating alloantigen-specific CD4 + CD25 + T cells. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Antioxidant defense parameters as predictive biomarkers for fermentative capacity of active dried wine yeast.

PubMed

Gamero-Sandemetrio, Esther; Gómez-Pastor, Rocío; Matallana, Emilia

2014-08-01

The production of active dried yeast (ADY) is a common practice in industry for the maintenance of yeast starters and as a means of long term storage. The process, however, causes multiple cell injuries, with oxidative damage being one of the most important stresses. Consequentially, dehydration tolerance is a highly appreciated property in yeast for ADY production. In this study we analyzed the cellular redox environment in three Saccharomyces cerevisiae wine strains, which show markedly different fermentative capacities after dehydration. To measure/quantify the effect of dehydration on the S. cerevisiae strains, we used: (i) fluorescent probes; (ii) antioxidant enzyme activities; (ii) intracellular damage; (iii) antioxidant metabolites; and (iv) gene expression, to select a minimal set of biochemical parameters capable of predicting desiccation tolerance in wine yeasts. Our results show that naturally enhanced antioxidant defenses prevent oxidative damage after wine yeast biomass dehydration and improve fermentative capacity. Based on these results we chose four easily assayable parameters/biomarkers for the selection of industrial yeast strains of interest for ADY production: trehalose and glutathione levels, and glutathione reductase and catalase enzymatic activities. Yeast strains selected in accordance with this process display high levels of trehalose, low levels of oxidized glutathione, a high induction of glutathione reductase activity, as well as a high basal level and sufficient induction of catalase activity, which are properties inherent in superior ADY strains. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cytokines affecting CD4+T regulatory cells in transplant tolerance. III. Interleukin-5 (IL-5) promotes survival of alloantigen-specific CD4+ T regulatory cells.

PubMed

Hall, Bruce M; Plain, Karren M; Tran, Giang T; Verma, Nirupama D; Robinson, Catherine M; Nomura, Masaru; Boyd, Rochelle; Hodgkinson, Suzanne J

2017-08-01

CD4 + T cells mediate antigen-specific allograft tolerance, but die in culture without activated lymphocyte derived cytokines. Supplementation of the media with cytokine rich supernatant, from ConA activated spleen cells, preserves the capacity of tolerant cells to transfer tolerance and suppress rejection. rIL-2 or rIL-4 alone are insufficient to maintain these cells, however. We observed that activation of naïve CD4 + CD25 + FOXP3 + Treg with alloantigen and the Th2 cytokine rIL-4 induces them to express interleukin-5 specific receptor alpha (IL-5Rα) suggesting that IL-5, a Th2 cytokine that is produced later in the immune response may promote tolerance mediating Treg. This study examined if recombinant IL-5(rIL-5) promoted survival of tolerant CD4 + , especially CD4 + CD25 + T cells. CD4 + T cells, from DA rats tolerant to fully allogeneic PVG heart allografts surviving over 100days without on-going immunosuppression, were cultured with PVG alloantigen and rIL-5. The ability of these cells to adoptively transfer tolerance to specific-donor allograft and suppress normal CD4 + T cell mediated rejection in adoptive DA hosts was examined. Tolerant CD4 + CD25 + T cells' response to rIL-5 and expression of IL-5Rα was also assessed. rIL-5 was sufficient to promote transplant tolerance mediating CD4 + T cells' survival in culture with specific-donor alloantigen. Tolerant CD4 + T cells cultured with rIL-5 retained the capacity to transfer alloantigen-specific tolerance and inhibited naïve CD4 + T cells' capacity to effect specific-donor graft rejection. rIL-5 promoted tolerant CD4 + CD25 + T cells' proliferation in vitro when stimulated with specific-donor but not third-party stimulator cells. Tolerant CD4 + CD25 + T cells expressed IL-5Rα. This study demonstrated that IL-5 promoted the survival of alloantigen-specific CD4 + CD25 + T cells that mediate transplant tolerance. Copyright © 2017 Elsevier B.V. All rights reserved.

Specific oral tolerance induction with raw hen's egg in children with very severe egg allergy: a randomized controlled trial.

PubMed

Dello Iacono, Iride; Tripodi, Salvatore; Calvani, Mauro; Panetta, Valentina; Verga, Maria Carmela; Miceli Sopo, Stefano

2013-02-01

Treatment of severe egg allergy is avoidance of hen's egg (HE) and carrying self-injectable epinephrine. Specific oral tolerance induction (SOTI) seems a promising alternative treatment. However, some aspects of SOTI are still considered experimental. We evaluated the efficacy and safety of an original 6-month SOTI protocol in children with very severe HE allergy using raw HE emulsion. Twenty children (age range: 5-11 yr) were randomized equally into a SOTI treatment group and a control group. The treatment group started SOTI and underwent a second challenge 6 months later. Control children were kept on an egg-free diet for 6 months and then underwent a second challenge. After 6 months, 9/10 children of the SOTI group (90%) achieved partial tolerance (at least 10 ml, but <40 ml of raw HE emulsion, in a single dose) and 1 (10%) was able to tolerate only 5 ml (no tolerance). After 6 months, nine control children tested positive to the second challenge at a dose ≤0.9 ml of raw HE emulsion, and one reacted to 1.8 ml (SOTI vs. control group p<0.0001). All children in the SOTI group had side effects, but no child had a grade 5 reaction according to the Sampson grading. Six months of SOTI with raw HE emulsion resulted in partial tolerance, with regular intake, in a significant percentage of children with severe egg allergy. © 2012 John Wiley & Sons A/S.

PD-1 regulates extrathymic regulatory T-cell differentiation

PubMed Central

Chen, Xiufen; Fosco, Dominick; Kline, Douglas E.; Meng, Liping; Nishi, Saki; Savage, Peter A.; Kline, Justin

2014-01-01

Regulatory T (Treg) cells and the programmed death-1/programmed death ligand-1 (PD-1/PD-L1) pathway are both critical for maintaining peripheral tolerance to self antigens. A significant subset of Treg cells constitutively expresses PD-1, which prompted an investigation into the role of PD-1/PD-L1 interactions in Treg-cell development, function and induction in vivo. The phenotype and abundance of Treg cells was not significantly altered in PD-1-deficient mice. The thymic development of polyclonal and monospecific Treg cells was not negatively impacted by PD-1 deficiency. The suppressive function of PD-1−/− Treg cells was similar to their PD-1+/+ counterparts both in vitro and in vivo. However, in three different in vivo experimental settings, PD-1−/− conventional CD4+ T cells demonstrated a strikingly diminished tendency toward differentiation into peripherally induced Treg (pTreg) cells. Our results demonstrate that PD-1 is dispensable for thymic (tTreg) Treg-cell development and suppressive function, but is critical for the extrathymic differentiation of pTreg cells in vivo. These data suggest that antibody blockade of the PD-1/PD-L1 pathway may augment T-cell responses by acting directly on conventional T cells, and also by suppressing the differentiation of pTreg cells. PMID:24975127

Gene expression of Escherichia coli in continuous culture during adaptation to artificial sunlight.

PubMed

Berney, Michael; Weilenmann, Hans-Ulrich; Egli, Thomas

2006-09-01

Escherichia coli growing in continuous culture under continuous UVA irradiation exhibits growth inhibition with a subsequent adaptation to the stress. Transcriptome analysis was performed during transient growth inhibition and in the UVA light-adapted growth state. The results indicate that UVA light induces stringent response and an additional response that includes the upregulation of the synthesis of valine, isoleucine, leucine, phenylalanine, histidine and glutamate. The induction of several SOS response-genes strongly points to DNA damage as a result of UVA exposure. The involvement of oxidative stress was observed with the induction of ahpCF. Taken together it supports the hypothesis of the production of reactive oxygen species by UVA light. In the UVA-adapted cell population strong repression of the acid tolerance response was found. We identified the enzyme chorismate mutase as a possible chromophore for UVA light-inactivation and found strong repression of the pyrBI operon and the gene mgtA encoding for an ATP-dependent Mg2+ transporter. Furthermore, our results indicate that the role of RpoS may not be as important in the adaptation of E. coli to UVA light as it was implicated by previous results with starved cells, but that RpoS might be of crucial importance for the resistance under transient light exposure.

New investigations into the genotoxicity of cobalt compounds and their impact on overall assessment of genotoxic risk.

PubMed

Kirkland, David; Brock, Tom; Haddouk, Hasnaà; Hargeaves, Victoria; Lloyd, Melvyn; Mc Garry, Sarah; Proudlock, Raymond; Sarlang, Séverine; Sewald, Katherina; Sire, Guillaume; Sokolowski, Andrea; Ziemann, Christina

2015-10-01

The genotoxicity of cobalt metal and cobalt compounds has been widely studied. Several publications show induction of chromosomal aberrations, micronuclei or DNA damage in mammalian cells in vitro in the absence of S9. Mixed results were seen in gene mutation studies in bacteria and mammalian cells in vitro, and in chromosomal aberration or micronucleus assays in vivo. To resolve these inconsistencies, new studies were performed with soluble and poorly soluble cobalt compounds according to OECD-recommended protocols. Induction of chromosomal damage was confirmed in vitro, but data suggest this may be due to oxidative stress. No biologically significant mutagenic responses were obtained in bacteria, Tk(+/-) or Hprt mutation tests. Negative results were also obtained for chromosomal aberrations (in bone marrow and spermatogonia) and micronuclei at maximum tolerated doses in vivo. Poorly soluble cobalt compounds do not appear to be genotoxic. Soluble compounds do induce some DNA and chromosomal damage in vitro, probably due to reactive oxygen. The absence of chromosome damage in robust GLP studies in vivo suggests that effective protective processes are sufficient to prevent oxidative DNA damage in whole mammals. Overall, there is no evidence of genetic toxicity with relevance for humans of cobalt substances and cobalt metal. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

The Kraken Wakes: induced EMT as a driver of tumour aggression and poor outcome.

PubMed

Redfern, Andrew D; Spalding, Lisa J; Thompson, Erik W

2018-06-08

Epithelial mesenchymal transition (EMT) describes the shift of cells from an epithelial form to a contact independent, migratory, mesenchymal form. In cancer the change is linked to invasion and metastasis. Tumour conditions, including hypoxia, acidosis and a range of treatments can trigger EMT, which is implicated in the subsequent development of resistance to those same treatments. Consequently, the degree to which EMT occurs may underpin the entire course of tumour progression and treatment response in a patient. In this review we look past the protective effect of EMT against the initial treatment, to the role of the mesenchymal state, once triggered, in promoting disease growth, spread and future treatment insensitivity. In patients a correlation was found between the propensity of a treatment to induce EMT and failure of that treatment to provide a survival benefit, implicating EMT induction in accelerated tumour progression after treatment cessation. Looking to the mechanisms driving this detrimental effect; increased proliferation, suppressed apoptosis, stem cell induction, augmented angiogenesis, enhanced metastatic dissemination, and immune tolerance, can all result from treatment-induced EMT and could worsen outcome. Evidence also suggests EMT induction with earlier therapies attenuates benefits of later treatments. Looking beyond epithelial tumours, de-differentiation also has therapy-attenuating effects and reversal thereof may yield similar rewards. A range of potential therapies are in development that may address the diverse mechanisms and molecular control systems involved in EMT-induced accelerated progression. Considering the broad reaching effects of mesenchymal shift identified, successful deployment of such treatments could substantially improve patient outcomes.

Malignant induction probability maps for radiotherapy using X-ray and proton beams.

PubMed

Timlin, C; Houston, M; Jones, B

2011-12-01

The aim of this study was to display malignant induction probability (MIP) maps alongside dose distribution maps for radiotherapy using X-ray and charged particles such as protons. Dose distributions for X-rays and protons are used in an interactive MATLAB® program (MathWorks, Natick, MA). The MIP is calculated using a published linear quadratic model, which incorporates fractionation effects, cell killing and cancer induction as a function of dose, as well as relative biological effect. Two virtual situations are modelled: (a) a tumour placed centrally in a cubic volume of normal tissue and (b) the same tumour placed closer to the skin surface. The MIP is calculated for a variety of treatment field options. The results show that, for protons, the MIP increases with field numbers. In such cases, proton MIP can be higher than that for X-rays. Protons produce the lowest MIPs for superficial targets because of the lack of exit dose. The addition of a dose bath to all normal tissues increases the MIP by up to an order of magnitude. This exploratory study shows that it is possible to achieve three-dimensional displays of carcinogenesis risk. The importance of treatment geometry, including the length and volume of tissue traversed by each beam, can all influence MIP. Reducing the volume of tissue irradiated is advantageous, as reducing the number of cells at risk reduces the total MIP. This finding lends further support to the use of treatment gantries as well as the use of simpler field arrangements for particle therapy provided normal tissue tolerances are respected.

Allergen-specific T-cell tolerance induction with allergen-derived long synthetic peptides: results of a phase I trial.

PubMed

Fellrath, Jean-Marc; Kettner, Alexander; Dufour, Nathalie; Frigerio, Christian; Schneeberger, Dominique; Leimgruber, Annette; Corradin, Gampietro; Spertini, François

2003-04-01

There is a need to improve the safety and efficacy of allergen-specific immunotherapy. Long synthetic peptide-based immunotherapy was proven safe, immunogenic, and protective in preclinical trials. To evaluate the safety and immunogenicity of an allergen-derived long synthetic overlapping peptide (LSP) immunotherapy, we designed a double-blind, placebo-controlled phase I clinical trial in patients hypersensitive to bee venom. Patients from the active group were injected at day 0 with a mixture of 3 LSPs mapping the entire PLA2 molecule, a major bee venom allergen, in a dose-escalating protocol to a maintenance dose of 100 microg per peptide repeated at days 4, 7, 14, 42, and 70. The control group was injected with human albumin. Whereas specific T-cell proliferation in the peptide group increased up to day 14, a sharp decline was observed thereafter, ending in specific T-cell hyporesponsiveness at day 80. Serum-specific IgG4 response was enhanced, in contrast to anti-PLA2 IgE. Specific T-cell cytokine modulation was marked by increased IL-10 and IFN-gamma secretion. LSP injections were well tolerated in all patients except for mild, late allergic reactions in 2 patients at day 70. The results of this short-term study demonstrate that LSP-based allergen immunotherapy was safe and able to induce T(H)1-type immune deviation, allergen-specific IL-10 production, and T-cell hyporesponsiveness. LSPs, which offer the advantage of covering all possible T-cell epitopes for any HLA genotype, can be considered candidates for a novel and safe approach of specific immunotherapy.

Allergen-specific immunotherapy: update on immunological mechanisms.

PubMed

Alvaro, M; Sancha, J; Larramona, H; Lucas, J M; Mesa, M; Tabar, A I; Martinez-Cañavate, A

2013-01-01

Immunotherapy selectively modulates the allergen-specific immune response. It involves the gradual administration of increasing amounts of allergen for the purpose of inducing protective immunological changes and it is the only curative approach for specific type I allergy. Description of the allergic inflammation.- Comprehension of the early cellular changes after specific immunotherapy has been initiated. Exposure of the mechanisms involved in tolerance induction by regulatory T cells (Treg) with the inhibition of the Th2 responses. Comprehension of IL-10 and transforming growth factor (TGF- ) roles. Explanation of specific IgE, IgG and IgA changes. Description of the suppression of inflammatory responses during immunotherapy. Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.

Limited hair cell induction from human induced pluripotent stem cells using a simple stepwise method.

PubMed

Ohnishi, Hiroe; Skerleva, Desislava; Kitajiri, Shin-ichiro; Sakamoto, Tatsunori; Yamamoto, Norio; Ito, Juichi; Nakagawa, Takayuki

2015-07-10

Disease-specific induced pluripotent stem cells (iPS) cells are expected to contribute to exploring useful tools for studying the pathophysiology of inner ear diseases and to drug discovery for treating inner ear diseases. For this purpose, stable induction methods for the differentiation of human iPS cells into inner ear hair cells are required. In the present study, we examined the efficacy of a simple induction method for inducing the differentiation of human iPS cells into hair cells. The induction of inner ear hair cell-like cells was performed using a stepwise method mimicking inner ear development. Human iPS cells were sequentially transformed into the preplacodal ectoderm, otic placode, and hair cell-like cells. As a first step, preplacodal ectoderm induction, human iPS cells were seeded on a Matrigel-coated plate and cultured in a serum free N2/B27 medium for 8 days according to a previous study that demonstrated spontaneous differentiation of human ES cells into the preplacodal ectoderm. As the second step, the cells after preplacodal ectoderm induction were treated with basic fibroblast growth factor (bFGF) for induction of differentiation into otic-placode-like cells for 15 days. As the final step, cultured cells were incubated in a serum free medium containing Matrigel for 48 days. After preplacodal ectoderm induction, over 90% of cultured cells expressed the genes that express in preplacodal ectoderm. By culture with bFGF, otic placode marker-positive cells were obtained, although their number was limited. Further 48-day culture in serum free media resulted in the induction of hair cell-like cells, which expressed a hair cell marker and had stereocilia bundle-like constructions on their apical surface. Our results indicate that hair cell-like cells are induced from human iPS cells using a simple stepwise method with only bFGF, without the use of xenogeneic cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

LHCSR3 affects de-coupling and re-coupling of LHCII to PSII during state transitions in Chlamydomonas reinhardtii

PubMed Central

Roach, Thomas; Na, Chae Sun

2017-01-01

Photosynthetic organisms have to tolerate rapid changes in light intensity, which is facilitated by non-photochemical quenching (NPQ) and involves modification of energy transfer from light-harvesting complexes (LHC) to the photosystem reaction centres. NPQ includes dissipating excess light energy to heat (qE) and the reversible coupling of LHCII to photosystems (state transitions/qT), which are considered separate NPQ mechanisms. In the model alga Chlamydomonas reinhardtii the LHCSR3 protein has a well characterised role in qE. Here, it is shown in the npq4 mutant, deficient in LHCSR3, that energy coupling to photosystem II (PSII) more akin to qT is also disrupted, but no major differences in LHC phosphorylation or LHC compositions were found in comparison to wild-type cells. The qT of wild-type cells possessed two kinetically distinguishable phases, with LHCSR3 participating in the more rapid (<2 min) phase. This LHCSR3-mediated qT was sensitive to physiological levels of H2O2, which accelerated qE induction, revealing a way that may help C. reinhardtii tolerate a sudden increase in light intensity. Overall, a clear mechanistic overlap between qE and qT is shown. PMID:28233792

Hyperspectral imaging to identify salt-tolerant wheat lines

NASA Astrophysics Data System (ADS)

Moghimi, Ali; Yang, Ce; Miller, Marisa E.; Kianian, Shahryar; Marchetto, Peter

2017-05-01

In order to address the worldwide growing demand for food, agriculture is facing certain challenges and limitations. One of the important threats limiting crop productivity is salinity. Identifying salt tolerate varieties is crucial to mitigate the negative effects of this abiotic stress in agricultural production systems. Traditional measurement methods of this stress, such as biomass retention, are labor intensive, environmentally influenced, and often poorly correlated to salinity stress alone. In this study, hyperspectral imaging, as a non-destructive and rapid method, was utilized to expedite the process of identifying relatively the most salt tolerant line among four wheat lines including Triticum aestivum var. Kharchia, T. aestivum var. Chinese Spring, (Ae. columnaris) T. aestivum var. Chinese Spring, and (Ae. speltoides) T. aestivum var. Chinese Spring. To examine the possibility of early detection of a salt tolerant line, image acquisition was started one day after stress induction and continued on three, seven, and 12 days after adding salt. Simplex volume maximization (SiVM) method was deployed to detect superior wheat lines in response to salt stress. The results of analyzing images taken as soon as one day after salt induction revealed that Kharchia and (columnaris)Chinese Spring are the most tolerant wheat lines, while (speltoides) Chinese Spring was a moderately susceptible, and Chinese Spring was a relatively susceptible line to salt stress. These results were confirmed with the measuring biomass performed several weeks later.

C-Rel is an essential transcription factor for the development of acute graft-versus-host disease in mice

PubMed Central

Yu, Yu; Wang, Dapeng; Kaosaard, Kane; Liu, Chen; Fu, Jianing; Haarberg, Kelley; Anasetti, Claudio; Beg, Amer A.; Yu, Xue-Zhong

2014-01-01

Transcription factor of the Rel/NF-κB family are known to play different roles in immunity and inflammation, although the putative role of c-Rel in transplant tolerance and GVHD remains elusive. We report here that T cells deficient for c-Rel have a dramatically reduced ability to cause acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) using major and minor histocompatibility mismatched murine models. In the study to understand the underlying mechanisms, we found that c-Rel-/- T cells had reduced ability to expand in lymphoid organs and to infiltrate in GVHD target organs in allogeneic recipients. c-Rel-/- T cells were defective in the differentiation into Th1 cells after encountering alloantigens, but were enhanced in the differentiation towards Foxp3+ regulatory T cells (Tregs). Furthermore, c-Rel-/- T cells had largely preserved activity to mediate graft-versus leukemia (GVL) response. Taken together, our findings indicate that c-Rel plays an essential role in T cells in the induction of acute GVHD, and suggest that c-Rel can be a potential target for therapeutic intervention in allogeneic HCT in clinic. PMID:23716202

Tissue-Resident Lymphocytes in Solid Organ Transplantation: Innocent Passengers or the Key to Organ Transplant Survival?

PubMed

Prosser, Amy C; Kallies, Axel; Lucas, Michaela

2018-03-01

Short-term outcomes of solid organ transplantation have improved dramatically over the past several decades; however, long-term survival has remained static over the same period, and chronic rejection remains a major cause of graft failure. The importance of donor, or "passenger," lymphocytes to the induction of tolerance to allografts was recognized in the 1990s, but their precise contribution to graft acceptance or rejection has not been elucidated. Recently, specialized populations of tissue-resident lymphocytes in nonlymphoid organs have been described. These lymphocytes include tissue-resident memory T cells, regulatory T cells, γδ T cells, invariant natural killer T cells, and innate lymphoid cells. These cells reside in commonly transplanted solid organs, including the liver, kidneys, heart, and lung; however, their contribution to graft acceptance or rejection has not been examined in detail. Similarly, it is unclear whether tissue-resident cells derived from the pool of recipient-derived lymphocytes play a specific role in transplantation biology. This review summarizes the evidence for the roles of tissue-resident lymphocytes in transplant immunology, focussing on their features, functions, and relevance for solid organ transplantation, with specific reference to liver, kidney, heart, and lung transplantation.

Depletion of suppressor T cells by 2'-deoxyguanosine abrogates tolerance in mice fed ovalbumin and permits the induction of intestinal delayed-type hypersensitivity.

PubMed Central

Mowat, A M

1986-01-01

We have re-examined the role of suppressor T cells (Ts) in regulating immune responses to fed proteins by investigating the effect of 2'-deoxyguanosine (dGuo) on systemic and intestinal immunity in mice fed ovalbumin (OVA). Administration of dGuo for 10 days abrogated the suppression of systemic delayed-type hypersensitivity (DTH) and antibody responses normally found after feeding OVA, and also prevented the generation of OVA-specific Ts. In parallel, mice given dGuo and fed OVA developed sensitization to OVA in the gut-associated lymphoid tissues (GALT) after oral challenge with OVA and had increased intraepithelial lymphocyte (IEL) counts and crypt cell production rates (CCPR) in the jejunal mucosa, indicating the presence of a local DTH response. These findings confirm the importance of Ts in preventing hypersensitivity to dietary protein antigens and suggest that enteropathies associated with food hypersensitivity are due to a defect in Ts activity. PMID:2940171

Improving the efficacy and safety of biologic drugs with tolerogenic nanoparticles

NASA Astrophysics Data System (ADS)

Kishimoto, Takashi K.; Ferrari, Joseph D.; Lamothe, Robert A.; Kolte, Pallavi N.; Griset, Aaron P.; O'Neil, Conlin; Chan, Victor; Browning, Erica; Chalishazar, Aditi; Kuhlman, William; Fu, Fen-Ni; Viseux, Nelly; Altreuter, David H.; Johnston, Lloyd; Maldonado, Roberto

2016-10-01

The development of antidrug antibodies (ADAs) is a common cause for the failure of biotherapeutic treatments and adverse hypersensitivity reactions. Here we demonstrate that poly(lactic-co-glycolic acid) (PLGA) nanoparticles carrying rapamycin, but not free rapamycin, are capable of inducing durable immunological tolerance to co-administered proteins that is characterized by the induction of tolerogenic dendritic cells, an increase in regulatory T cells, a reduction in B cell activation and germinal centre formation, and the inhibition of antigen-specific hypersensitivity reactions. Intravenous co-administration of tolerogenic nanoparticles with pegylated uricase inhibited the formation of ADAs in mice and non-human primates and normalized serum uric acid levels in uricase-deficient mice. Similarly, the subcutaneous co-administration of nanoparticles with adalimumab resulted in the durable inhibition of ADAs, leading to normalized pharmacokinetics of the anti-TNFα antibody and protection against arthritis in TNFα transgenic mice. Adjunct therapy with tolerogenic nanoparticles represents a novel and broadly applicable approach to prevent the formation of ADAs against biologic therapies.

Fludarabine and rituximab with escalating doses of lenalidomide followed by lenalidomide/rituximab maintenance in previously untreated chronic lymphocytic leukaemia (CLL): the REVLIRIT CLL-5 AGMT phase I/II study.

PubMed

Egle, Alexander; Steurer, Michael; Melchardt, Thomas; Weiss, Lukas; Gassner, Franz Josef; Zaborsky, Nadja; Geisberger, Roland; Catakovic, Kemal; Hartmann, Tanja Nicole; Pleyer, Lisa; Voskova, Daniela; Thaler, Josef; Lang, Alois; Girschikofsky, Michael; Petzer, Andreas; Greil, Richard

2018-06-04

Despite recent advances, chemoimmunotherapy remains a standard for fit previously untreated chronic lymphocytic leukaemia patients. Lenalidomide had activity in early monotherapy trials, but tumour lysis and flare proved major obstacles in its development. We combined lenalidomide in increasing doses with six cycles of fludarabine and rituximab (FR), followed by lenalidomide/rituximab maintenance. In 45 chemo-naive patients, included in this trial, individual tolerability of the combination was highly divergent and no systematic toxicity determining a maximum tolerated dose was found. Grade 3/4 neutropenia (71%) was high, but only 7% experienced grade 3 infections. No tumour lysis or flare > grade 2 was observed, but skin toxicity proved dose-limiting in nine patients (20%). Overall and complete response rates after induction were 89 and 44% by intention-to-treat, respectively. At a median follow-up of 78.7 months, median progression-free survival (PFS) was 60.3 months. Minimal residual disease and immunoglobulin variable region heavy chain mutation state predicted PFS and TP53 mutation most strongly predicted OS. Baseline clinical factors did not predict tolerance to the immunomodulatory drug lenalidomide, but pretreatment immunophenotypes of T cells showed exhausted memory CD4 cells to predict early dose-limiting non-haematologic events. Overall, combining lenalidomide with FR was feasible and effective, but individual changes in the immune system seemed associated with limiting side effects. clinicaltrials.gov (NCT00738829) and EU Clinical Trials Register ( www.clinicaltrialsregister.eu , 2008-001430-27).

Mifepristone (RU486) restores humoral and T cell-mediated immune response in endotoxin immunosuppressed mice

PubMed Central

Rearte, B; Maglioco, A; Balboa, L; Bruzzo, J; Landoni, V I; Laborde, E A; Chiarella, P; Ruggiero, R A; Fernández, G C; Isturiz, M A

2010-01-01

Sepsis and septic shock can be caused by Gram-positive and -negative bacteria and other microorganisms. In the case of Gram-negative bacteria, endotoxin, a normal constituent of the bacterial wall, also known as lipopolysaccharide (LPS), has been considered as one of the principal agents causing the undesirable effects in this critical illness. The response to LPS involves a rapid secretion of proinflammatory cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, interferon (IFN)-γ and the concomitant induction of anti-inflammatory mediators such as IL-10, transforming growth factor (TGF)-β or glucocorticoids, which render the host temporarily refractory to subsequent lethal doses of LPS challenge in a process known as LPS or endotoxin tolerance. Although protective from the development of sepsis or systemic inflammation, endotoxin tolerance has also been pointed out as the main cause of the non-specific humoral and cellular immunosuppression described in these patients. In this report we demonstrate, using a mouse model, that mifepristone (RU486), a known glucocorticoid receptor antagonist, could play an important role in the restoration of both adaptive humoral and cellular immune response in LPS immunosuppressed mice, suggesting the involvement of endogenous glucocorticoids in this phenomenon. On the other hand, using cyclophosphamide and gemcitabine, we demonstrated that regulatory/suppressor CD4+CD25+forkhead boxP3+ and GR-1+CD11b+ cells do not play a major role in the establishment or the maintenance of endotoxin tolerance, a central mechanism for inducing an immunosuppression state. PMID:20964639

Update on Aire and thymic negative selection.

PubMed

Passos, Geraldo A; Speck-Hernandez, Cesar A; Assis, Amanda F; Mendes-da-Cruz, Daniella A

2018-01-01

Twenty years ago, the autoimmune regulator (Aire) gene was associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, and was cloned and sequenced. Its importance goes beyond its abstract link with human autoimmune disease. Aire identification opened new perspectives to better understand the molecular basis of central tolerance and self-non-self distinction, the main properties of the immune system. Since 1997, a growing number of immunologists and molecular geneticists have made important discoveries about the function of Aire, which is essentially a pleiotropic gene. Aire is one of the functional markers in medullary thymic epithelial cells (mTECs), controlling their differentiation and expression of peripheral tissue antigens (PTAs), mTEC-thymocyte adhesion and the expression of microRNAs, among other functions. With Aire, the immunological tolerance became even more apparent from the molecular genetics point of view. Currently, mTECs represent the most unusual cells because they express almost the entire functional genome but still maintain their identity. Due to the enormous diversity of PTAs, this uncommon gene expression pattern was termed promiscuous gene expression, the interpretation of which is essentially immunological - i.e. it is related to self-representation in the thymus. Therefore, this knowledge is strongly linked to the negative selection of autoreactive thymocytes. In this update, we focus on the most relevant results of Aire as a transcriptional and post-transcriptional controller of PTAs in mTECs, its mechanism of action, and its influence on the negative selection of autoreactive thymocytes as the bases of the induction of central tolerance and prevention of autoimmune diseases. © 2017 John Wiley & Sons Ltd.

Copackaged AAV9 Vectors Promote Simultaneous Immune Tolerance and Phenotypic Correction of Pompe Disease

PubMed Central

Doerfler, Phillip A.; Todd, Adrian G.; Clément, Nathalie; Falk, Darin J.; Nayak, Sushrusha; Herzog, Roland W.; Byrne, Barry J.

2016-01-01

Pompe disease is a progressive neuromuscular disorder caused by lysosomal accumulation of glycogen from a deficiency in acid alpha-glucosidase (GAA). Replacement of the missing enzyme is available by repeated protein infusions; however, efficacy is limited by immune response and inability to restore enzymatic function in the central nervous system. An alternative therapeutic option is adeno-associated virus (AAV)-mediated gene therapy, which results in widespread gene transfer and prolonged transgene expression. Both enzyme replacement therapy (ERT) and gene therapy can elicit anti-GAA immune reactions that dampen their effectiveness and pose life-threatening risks to patient safety. To modulate the immune responses related to gene therapy, we show that a human codon-optimized GAA (coGAA) driven by a liver-specific promoter (LSP) using AAV9 is capable of promoting immune tolerance in a Gaa−/− mouse model. Copackaging AAV9-LSP-coGAA with the tissue-restricted desmin promoter (AAV9-DES-coGAA) demonstrates the necessary cell autonomous expression in cardiac muscle, skeletal muscle, peripheral nerve, and the spinal cord. Simultaneous high-level expression in liver led to the expansion of GAA-specific regulatory T-cells (Tregs) and induction of immune tolerance. Transfer of Tregs into naïve recipients prevented pathogenic allergic reactions after repeated ERT challenges. Copackaged AAV9 also attenuated preexisting humoral and cellular immune responses, which enhanced the biochemical correction. Our data present a therapeutic design in which simultaneous administration of two copackaged AAV constructs may provide therapeutic benefit and resolve immune reactions in the treatment of multisystem disorders. PMID:26603344

Survival of Deinococcus geothermalis in Biofilms under Desiccation and Simulated Space and Martian Conditions

NASA Astrophysics Data System (ADS)

Frösler, Jan; Panitz, Corinna; Wingender, Jost; Flemming, Hans-Curt; Rettberg, Petra

2017-05-01

Biofilm formation represents a successful survival strategy for bacteria. In biofilms, cells are embedded in a matrix of extracellular polymeric substances (EPS). As they are often more stress-tolerant than single cells, biofilm cells might survive the conditions present in space and on Mars. To investigate this topic, the bacterium Deinococcus geothermalis was chosen as a model organism due to its tolerance toward desiccation and radiation. Biofilms cultivated on membranes and, for comparison, planktonically grown cells deposited on membranes were air-dried and exposed to individual stressors that included prolonged desiccation, extreme temperatures, vacuum, simulated martian atmosphere, and UV irradiation, and they were exposed to combinations of stressors that simulate space (desiccation + vacuum + UV) or martian (desiccation + Mars atmosphere + UV) conditions. The effect of sulfatic Mars regolith simulant on cell viability during stress was investigated separately. The EPS produced by the biofilm cells contained mainly polysaccharides and proteins. To detect viable but nonculturable (VBNC) cells, cultivation-independent viability indicators (membrane integrity, ATP, 16S rRNA) were determined in addition to colony counts. Desiccation for 2 months resulted in a decrease of culturability with minor changes of membrane integrity in biofilm cells and major loss of membrane integrity in planktonic bacteria. Temperatures between -25°C and +60°C, vacuum, and Mars atmosphere affected neither culturability nor membrane integrity in both phenotypes. Monochromatic (254 nm; ≥1 kJ m-2) and polychromatic (200-400 nm; >5.5 MJ m-2 for planktonic cells and >270 MJ m-2 for biofilms) UV irradiation significantly reduced the culturability of D. geothermalis but did not affect cultivation-independent viability markers, indicating the induction of a VBNC state in UV-irradiated cells. In conclusion, a substantial proportion of the D. geothermalis population remained viable under all stress conditions tested, and in most cases the biofilm form proved advantageous for surviving space and Mars-like conditions.

Induction of proliferation of basal epidermal keratinocytes by cold atmospheric-pressure plasma.

PubMed

Hasse, S; Duong Tran, T; Hahn, O; Kindler, S; Metelmann, H-R; von Woedtke, T; Masur, K

2016-03-01

Over the past few decades, new cold plasma sources have been developed that have the great advantage of operating at atmospheric pressure and at temperatures tolerable by biological material. New applications for these have emerged, especially in the field of dermatology. Recently it was demonstrated that cold atmospheric-pressure plasma positively influences healing of chronic wounds. The potential of cold plasma lies in its capacity to reduce bacterial load in the wound while at the same time stimulating skin cells and therefore promoting wound closure. In recent years, there have been great advances in the understanding of the molecular mechanisms triggered by cold plasma involving signalling pathways and gene regulation in cell culture. To investigate cold plasma-induced effects in ex vivo treated human skin biopsies. Human skin tissue was exposed to cold plasma for different lengths of time, and analysed by immunofluorescence with respect to DNA damage, apoptosis, proliferation and differentiation markers. After cold plasma treatment, the epidermal integrity and keratin expression pattern remained unchanged. As expected, the results revealed an increase in apoptotic cells after 3 and 5 min of treatment. Strikingly, an induction of proliferating basal keratinocytes was detected after cold plasma exposure for 1 and 3 min. As these are the cells that regenerate the epidermis, this could indeed be beneficial for wound closure. We investigated the effect of cold plasma on human skin by detecting molecules for growth and apoptosis, and found that both processes are dependent on treatment time. Therefore, this approach offers promising results for further applications of cold plasma in clinical dermatology. © 2015 British Association of Dermatologists.

Quaternary ammonium salt N-(dodecyloxycarboxymethyl)-N,N,N-trimethyl ammonium chloride induced alterations in Saccharomyces cerevisiae physiology.

PubMed

Oblak, Ewa; Piecuch, Agata; Maciaszczyk-Dziubinska, Ewa; Wawrzycka, Donata

2016-12-01

We investigated the influence of the quaternary ammonium salt (QAS) called IM (N-(dodecyloxycarboxymethyl)- N,N,N-trimethyl ammonium chloride) on yeast cells of the parental strain and the IM-resistant mutant (EO25 IMR) growth. The phenotype of this mutant was pleiotropic. The IMR mutant exhibited resistance to ethanol, osmotic shock and oxidative stress, as well as increased sensitivity to UV. Moreover, it was noted that mutant EO25 appears to have an increased resistance to clotrimazole, ketoconazole, fluconazole, nystatin and cycloheximide. It also tolerated growth in the presence of crystal violet, DTT and metals (selenium, tin, arsenic). It was shown that the presence of IM decreased ergosterol level in mutant plasma membrane and increased its unsaturation. These results indicate changes in the cell lipid composition. Western blot analysis showed the induction of Pma1 level by IM. RT-PCR revealed an increased PMA1 expression after IM treatment.

Cell growth inhibition and apoptotic effects of a specific anti-RTFscFv antibody on prostate cancer, but not glioblastoma, cells

PubMed Central

Nejatollahi, Foroogh; Bayat, Payam; Moazen, Bahareh

2017-01-01

Background: Single chain antibody (scFv) has shown interesting results in cancer immunotargeting approaches, due to its advantages over monoclonal antibodies. Regeneration and tolerance factor (RTF) is one of the most important regulators of extracellular and intracellular pH in eukaryotic cells. In this study, the inhibitory effects of a specific anti-RTF scFv were investigated and compared between three types of prostate cancer and two types of glioblastoma cells.  Methods: A phage antibody display library of scFv was used to select specific scFvs against RTF using panning process. The reactivity of a selected scFv was assessed by phage ELISA. The anti-proliferative and apoptotic effects of the antibody on prostate cancer (PC-3, Du-145 and LNCaP) and glioblastoma (U-87 MG and A-172) cell lines were investigated by MTT and Annexin V/PI assays.  Results: A specific scFv with frequency 35% was selected against RTF epitope. This significantly inhibited the proliferation of the prostate cells after 24 h. The percentages of cell viability (using 1000 scFv/cell) were 52, 61 and 73% for PC-3, Du-145 and LNCaP cells, respectively, compared to untreated cells. The antibody (1000 scFv/cell) induced apoptosis at 50, 40 and 25% in PC-3, Du-145 and LNCaP cells, respectively. No growth inhibition and apoptotic induction was detected for U-87 and A172 glioblastoma cells.  Conclusions: Anti-RTFscFv significantly reduced the proliferation of the prostate cancer cells. The inhibition of cell growth and apoptotic induction effects in PC-3 cells were greater than Du-145 and LNCaP cells. This might be due to higher expression of RTF antigen in PC-3 cells and/or better accessibility of RTF to scFv antibody. The resistance of glioblastoma cells to anti-RTF scFv offers the existence of mechanism(s) that abrogate the inhibitory effect(s) of the antibody to RTF. The results suggest that the selected anti-RTF scFv antibody could be an effective new alternative for prostate cancer immunotherapy. PMID:28491282

Bet v 1-specific T-cell receptor/forkhead box protein 3 transgenic T cells suppress Bet v 1-specific T-cell effector function in an activation-dependent manner.

PubMed

Schmetterer, Klaus G; Haiderer, Daniela; Leb-Reichl, Victoria M; Neunkirchner, Alina; Jahn-Schmid, Beatrice; Küng, Hans J; Schuch, Karina; Steinberger, Peter; Bohle, Barbara; Pickl, Winfried F

2011-01-01

Regulatory T (Treg) cells establish and maintain tolerance to self-antigens and many foreign antigens, such as allergens, by suppressing effector T-cell proliferation and function. We have previously shown that human T-cell receptor (TCR) αβ-chains specific for allergen-derived epitopes confer allergen specificity on peripheral blood T cells of individuals with and without allergy. To study the feasibility of generating allergen-specific human Treg cells by retroviral transduction of a transcription unit encoding forkhead box protein 3 (FOXP3) and allergen-specific TCR αβ-chains. cDNAs encoding the α and β-chains of a Bet v 1(142-153)-specific TCR (TCR alpha variable region 6/TCR beta variable region 20) and human FOXP3 were linked via picornaviral 2A sequences and expressed as single translational unit from an internal ribosomal entry site-green fluorescence protein-containing retroviral vector. Retrovirally transduced peripheral blood T cells were tested for expression of transgenes, Treg phenotype, and regulatory capacity toward allergen-specific effector T cells. Transduced T cells displayed a Treg phenotype with clear-cut upregulation of CD25, CD39, and cytotoxic T-lymphocyte antigen 4. The transduced cells were hyporesponsive in cytokine production and secretion and, like naturally occurring Treg cells, did not proliferate after antigen-specific or antigen-mimetic stimulation. However, proliferation was inducible upon exposure to exogenous IL-2. In coculture experiments, TRAV6(+)TRBV20(+)FOXP3(+) transgenic T cells, unlike FOXP3(+) single transgenic T cells or naturally occurring Treg cells, highly significantly suppressed T cell cytokine production and proliferation of corresponding allergen-specific effector T cells in an allergen-specific, dose-dependent manner. We demonstrate a transgenic approach to engineer human allergen-specific Treg cells that exert their regulatory function in an activation-dependent manner. Customized Treg cells might become useful for tolerance induction therapies in individuals with allergic and other immune-mediated diseases. Copyright © 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Epigenomics and bolting tolerance in sugar beet genotypes.

PubMed

Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

2016-01-01

In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Continuous subcutaneous insulin infusion allows tolerance induction and diabetes treatment in a type 1 diabetic child with insulin allergy.

PubMed

Hasselmann, C; Pecquet, C; Bismuth, E; Raverdy, C; Sola-Gazagnes, A; Lobut, J-B; Carel, J-C; Tubiana-Rufi, N

2013-04-01

Insulin allergy is a rare but serious and challenging condition in patients with type 1 diabetes (T1D). This is a case report of an 8-year-old boy with T1D and an allergy to insulin. Three months after being diagnosed with T1D, the patient developed progressive skin reactions to insulin, characterized by small 1.5-cm pruritic wheals at injection sites that persisted for several days. Seven months after diagnosis, he experienced two episodes of generalized urticaria with systemic symptoms that were seen within a few seconds of insulin injection. Examination revealed lipoatrophy of the thighs. Intradermal skin tests were positive for protamine, glargine and lispro. The patient was started on a continuous subcutaneous insulin infusion (CSII) tolerance induction protocol, consisting of a very low basal rate that was progressively increased, with the first bolus given under medical supervision, and was well tolerated for 4 months. After this period of time, the skin wheals reappeared, localized to the infusion sites, but without urticaria or any other generalized reactions. Intradermal skin tests were repeated and were again positive. Serum insulin-specific IgE measured 30 months after the first allergic reactions were positive. After 3 years, pump therapy is ongoing and blood glucose control has remained relatively good (HbA1c 7.6%). In T1D children with insulin allergy, CSII can successfully be used to both induce insulin tolerance and allow diabetes insulin therapy, although insulin desensitization cannot always be fully achieved. The induction protocol was easily manageable partly due to the "honeymoon" period that the patient was still in, but it should nonetheless be used even when the patient has higher insulin requirements. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Soluble human leukocyte antigen G5 polarizes differentiation of macrophages toward a decidual macrophage-like phenotype.

PubMed

Lee, Cheuk-Lun; Guo, YiFan; So, Kam-Hei; Vijayan, Madhavi; Guo, Yue; Wong, Vera H H; Yao, YuanQing; Lee, Kai-Fai; Chiu, Philip C N; Yeung, William S B

2015-10-01

What are the actions of soluble human leukocyte antigen G5 (sHLAG5) on macrophage differentiation? sHLAG5 polarizes the differentiation of macrophages toward a decidual macrophage-like phenotype, which could regulate fetomaternal tolerance and placental development. sHLAG5 is a full-length soluble isoform of human leukocyte antigen implicated in immune tolerance during pregnancy. Low or undetectable circulating level of sHLAG5 in first trimester of pregnancy is associated with pregnancy complications such as pre-eclampsia and spontaneous abortion. Decidual macrophages are located in close proximity to invasive trophoblasts, and are involved in regulating fetomaternal tolerance and placental development. Human peripheral blood monocytes were differentiated into macrophages by treatment with granulocyte macrophage colony-stimulating factor in the presence or absence of recombinant sHLAG5 during the differentiation process. The phenotypes and the biological activities of the resulting macrophages were compared. Recombinant sHLAG5 was produced in Escherichia coli BL21 and the protein identity was verified by tandem mass spectrometry. The expression of macrophage markers were analyzed by flow cytometry and quantitative PCR. Phagocytosis was determined by flow cytometry. Indoleamine 2,3-dioxygenase 1 expression and activity were measured by western blot analysis and kynurenine assay, respectively. Cell proliferation and cell cycling were determined by fluorometric cell proliferation assay and flow cytometry, respectively. Cytokine secretion was determined by cytokine array and ELISA kits. Intracellular cytokine expression was measured by flow cytometry. Cell invasion and migration were determined by trans-well invasion and migration assay, respectively. sHLAG5 drove the differentiation of macrophages with 'immuno-modulatory' characteristics, including reduced expression of M1 macrophage marker CD86 and increased expression of M2 macrophage marker CD163. sHLAG5-polarized macrophages showed enhanced phagocytic activity. They also had higher expression and activity of indoleamine 2,3-dioxygenase 1, a phenotypic marker of decidual macrophages, which inhibited proliferation of autologous T-cells via induction of G0/G1 cell cycle arrest. In addition, sHLAG5-polarized macrophages had an increased secretion of interleukin-6 and C-X-C motif ligand 1, which inhibited interferon-γ production in T-cells and induction of trophoblast invasion, respectively. Most information on the phenotypes and biological activities of human decidual macrophages are based on past literatures. A direct comparison between sHLAG5-polarized macrophages and primary decidual macrophages is required to verify the present observations. This is the first study on the role of sHLAG5 in macrophage differentiation. Further study on the mechanism that regulates the differentiation process of macrophages would enhance our understanding on the physiology of early pregnancy. This work was supported in part by the Hong Kong Research Grant Council Grant HKU774212 and the University of Hong Kong Grant 201309176126. The authors have no competing interests to declare. Nil. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Subacute cutaneous lupus erythematosus: 25-year evolution of a prototypic subset (subphenotype) of lupus erythematosus defined by characteristic cutaneous, pathological, immunological, and genetic findings.

PubMed

Sontheimer, Richard D

2005-06-01

Subacute cutaneous lupus erythematosus (SCLE) represents a widespread, photosensitive, nonscarring, nonindurated form of lupus erythematosus (LE)-specific skin disease. SCLE lesions are associated with a distinctive immunogenetic background including the production of Ro/SS-A autoantibodies. Individuals who have SCLE skin lesions as a component of their presenting illnesses represent a distinctive subset (subphenotype) of LE that enjoys a good prognosis with respect to life-threatening systemic manifestations of LE. SCLE skin lesions can be triggered by a number of different drugs the majority of which are capable of producing photosensitivity drug reactions in nonlupus patients. Single agent or combination aminoquinoline antimalarial therapy will suffice for 75% of SCLE patients. The remaining 25% will require other forms of systemic antiinflammatory therapy (e.g., diaminodipenylsulfone (Dapsone), thalidomide) or systemic immunosuppressive-immunomodulatory therapy. The etiopathogenesis of SCLE skin lesions is thought to result from four sequential stages: (1) inheritance of susceptibility genes (HLA 8.1 ancestral haplotype [C2, C4 deficiency, TNF-alpha-308A polymorphism], C1q deficiency); (2) loss of tolerance/induction of autoimmunity (ultraviolet light, photosensitizing drugs/chemicals, cigarette smoking, infection, psychological stress); (3) expansion/maturation of autoimmune responses (high levels of autoantibodies (Ro/SS-A), immune complexes, autoreactive T-cells); and (4) tissue injury/disease induction resulting from various autoimmune effector mechanisms (e.g., direct T cell-mediated cytotoxicity, antibody-dependent cell-mediated cytotoxicity).

Whole Exome Sequencing Identifies Novel Genes for Fetal Hemoglobin Response to Hydroxyurea in Children with Sickle Cell Anemia

PubMed Central

Sheehan, Vivien A.; Crosby, Jacy R.; Sabo, Aniko; Mortier, Nicole A.; Howard, Thad A.; Muzny, Donna M.; Dugan-Perez, Shannon; Aygun, Banu; Nottage, Kerri A.; Boerwinkle, Eric; Gibbs, Richard A.; Ware, Russell E.; Flanagan, Jonathan M.

2014-01-01

Hydroxyurea has proven efficacy in children and adults with sickle cell anemia (SCA), but with considerable inter-individual variability in the amount of fetal hemoglobin (HbF) produced. Sibling and twin studies indicate that some of that drug response variation is heritable. To test the hypothesis that genetic modifiers influence pharmacological induction of HbF, we investigated phenotype-genotype associations using whole exome sequencing of children with SCA treated prospectively with hydroxyurea to maximum tolerated dose (MTD). We analyzed 171 unrelated patients enrolled in two prospective clinical trials, all treated with dose escalation to MTD. We examined two MTD drug response phenotypes: HbF (final %HbF minus baseline %HbF), and final %HbF. Analyzing individual genetic variants, we identified multiple low frequency and common variants associated with HbF induction by hydroxyurea. A validation cohort of 130 pediatric sickle cell patients treated to MTD with hydroxyurea was genotyped for 13 non-synonymous variants with the strongest association with HbF response to hydroxyurea in the discovery cohort. A coding variant in Spalt-like transcription factor, or SALL2, was associated with higher final HbF in this second independent replication sample and SALL2 represents an outstanding novel candidate gene for further investigation. These findings may help focus future functional studies and provide new insights into the pharmacological HbF upregulation by hydroxyurea in patients with SCA. PMID:25360671

Intratumoral injection of IFN-alpha dendritic cells after dacarbazine activates anti-tumor immunity: results from a phase I trial in advanced melanoma.

PubMed

Rozera, Carmela; Cappellini, Giancarlo Antonini; D'Agostino, Giuseppina; Santodonato, Laura; Castiello, Luciano; Urbani, Francesca; Macchia, Iole; Aricò, Eleonora; Casorelli, Ida; Sestili, Paola; Montefiore, Enrica; Monque, Domenica; Carlei, Davide; Napolitano, Mariarosaria; Rizza, Paola; Moschella, Federica; Buccione, Carla; Belli, Roberto; Proietti, Enrico; Pavan, Antonio; Marchetti, Paolo; Belardelli, Filippo; Capone, Imerio

2015-05-02

Advanced melanoma patients have an extremely poor long term prognosis and are in strong need of new therapies. The recently developed targeted therapies have resulted in a marked antitumor effect, but most responses are partial and some degree of toxicity remain the major concerns. Dendritic cells play a key role in the activation of the immune system and have been typically used as ex vivo antigen-loaded cell drugs for cancer immunotherapy. Another approach consists in intratumoral injection of unloaded DCs that can exploit the uptake of a wider array of tumor-specific and individual unique antigens. However, intratumoral immunization requires DCs endowed at the same time with properties typically belonging to both immature and mature DCs (i.e. antigen uptake and T cell priming). DCs generated in presence of interferon-alpha (IFN-DCs), due to their features of partially mature DCs, capable of efficiently up-taking, processing and cross-presenting antigens to T cells, could successfully carry out this task. Combining intratumoral immunization with tumor-destructing therapies can induce antigen release in situ, facilitating the injected DCs in triggering an antitumor immune response. We tested in a phase I clinical study in advanced melanoma a chemo-immunotherapy approach based on unloaded IFN-DCs injected intratumorally one day after administration of dacarbazine. Primary endpoint of the study was treatment safety and tolerability. Secondary endpoints were immune and clinical responses of patients. Six patients were enrolled, and only three completed the treatment. The chemo-immunotherapy was well tolerated with no major side effects. Three patients showed temporary disease stabilization and two of them showed induction of T cells specific for tyrosinase, NY-ESO-1 and gp100. Of interest, one patient showing a remarkable long-term disease stabilization kept showing presence of tyrosinase specific T cells in PBMC and high infiltration of memory T cells in the tumor lesion at 21 months. We tested a chemo-immunotherapeutic approach based on IFN-DCs injected intratumorally one day after DTIC in advanced melanoma. The treatment was well tolerated, and clinical and immunological responses, including development of vitiligo, were observed, therefore warranting additional clinical studies aimed at evaluating efficacy of this approach. Trial Registration Number not publicly available due to EudraCT regulations: https://www.clinicaltrialsregister.eu/doc/EU_CTR_FAQ.pdf.

Overexpression of Selenoprotein SelK in BGC-823 Cells Inhibits Cell Adhesion and Migration.

PubMed

Ben, S B; Peng, B; Wang, G C; Li, C; Gu, H F; Jiang, H; Meng, X L; Lee, B J; Chen, C L

2015-10-01

Effects of human selenoprotein SelK on the adhesion and migration ability of human gastric cancer BGC-823 cells using Matrigel adhesion and transwell migration assays, respectively, were investigated in this study. The Matrigel adhesion ability of BGC-823 cells that overexpressed SelK declined extremely significantly (p < 0.01) compared with that of the cells not expressing the protein. The migration ability of BGC-823 cells that overexpressed SelK also declined extremely significantly (p < 0.01). On the other hand, the Matrigel adhesion ability and migration ability of the cells that overexpressed C-terminally truncated SelK did not decline significantly. The Matrigel adhesion ability and migration ability of human embryonic kidney HEK-293 cells that overexpressed SelK did not show significant change (p > 0.05) with the cells that overexpressed the C-terminally truncated protein. In addition to the effect on Matrigel adhesion and migration, the overexpression of SelK also caused a loss in cell viability (as measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) colorimetric assay) and induced apoptosis as shown by confocal microscopy and flow cytometry. The cytosolic free Ca2+ level of these cells was significantly increased as detected by flow cytometry. But the overexpression of SelK in HEK-293 cells caused neither significant loss in cell viability nor apoptosis induction. Only the elevation of cytosolic free Ca2+ level in these cells was significant. Taken together, the results suggest that the overexpression of SelK can inhibit human cancer cell Matrigel adhesion and migration and cause both the loss in cell viability and induction of apoptosis. The release of intracellular Ca2+ from the endoplasmic reticulum might be a mechanism whereby the protein exerted its impact. Furthermore, only the full-length protein, but not C-terminally truncated form, was capable of producing such impact. The embryonic cells were not influenced by the elevation of free Ca2+ level in cytosol, probably due to their much greater tolerance to the variation.

Upregulation of CD94 on CD8+T Cells in Anterior Chamber-Associated Immune Deviation

PubMed Central

He, Hao; Yang, Peizeng; Jiang, Liqiong; Zhang, Junfeng; Zhao, Changlin; Chen, Lina; Lin, Xiaomin; Zhou, Hongyan; Kijlstra, Aize

2008-01-01

Background CD8+ regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The phenotype and characteristics of CD8+Treg in ACAID remain only poorly understood. Recent studies have reported that the CD94-Qa-1 system is implicated in the induction of ACAID CD8+Treg, but the functions and characteristics of CD8+CD94+T cells remain unclear. Results Both mRNA and protein of CD94 and NKG2A were markedly up-regulated on splenic CD8+T cells of ACAID mice compared with controls. Flow cytometric analysis showed that very few CD8+CD94+T cells express granzyme B, perforin and Foxp3. CD8+CD94+T cells, but not CD8+CD94-T cells, magnetically isolated from the spleens of ACAID mice, produced large amounts of TGF-beta1 and exhibited suppressive activity in vitro. Neutralization of TGF-beta1 caused reversal of suppression mediated by CD8+CD94+T cells. Conclusion CD8+CD94+T cells from ACAID mice exhibited suppressive activity in association with enhanced expression of TGF-beta1, suggesting that CD8+Treg are mainly distributed in CD94+T cell subpopulations. PMID:18816417

Modulation between high- and low-frequency transcutaneous electric nerve stimulation delays the development of analgesic tolerance in arthritic rats.

PubMed

Desantana, Josimari M; Santana-Filho, Valter J; Sluka, Kathleen A

2008-04-01

To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%-2%). Laboratory. Adult male Sprague-Dawley rats (N=36). Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100micros pulse duration. Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop.

Sustained suppression by Foxp3+ regulatory T cells is vital for infectious transplantation tolerance

PubMed Central

Kendal, Adrian R.; Chen, Ye; Regateiro, Frederico S.; Ma, Jianbo; Adams, Elizabeth; Cobbold, Stephen P.; Hori, Shohei

2011-01-01

A paradigm shift in immunology has been the recent discovery of regulatory T cells (T reg cells), of which CD4+Foxp3+ cells are proven as essential to self-tolerance. Using transgenic B6.Foxp3hCD2 mice to isolate and ablate Foxp3+ T reg cells with an anti-hCD2 antibody, we show for the first time that CD4+Foxp3+ cells are crucial for infectious tolerance induced by nonablative anti–T cell antibodies. In tolerant animals, Foxp3+ T reg cells are constantly required to suppress effector T cells still capable of causing tissue damage. Tolerated tissue contains T cells that are capable of rejecting it, but are prevented from doing so by therapeutically induced Foxp3+ T reg cells. Finally, Foxp3+ cells have been confirmed as the critical missing link through which infectious tolerance operates in vivo. Peripherally induced Foxp3+ cells sustain tolerance by converting naive T cells into the next generation of Foxp3+ cells. Empowering Foxp3+ regulatory T cells in vivo offers a tractable route to avoid and correct tissue immunopathology. PMID:21875958

A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

PubMed

Kakimi, Kazuhiro; Isobe, Midori; Uenaka, Akiko; Wada, Hisashi; Sato, Eiichi; Doki, Yuichiro; Nakajima, Jun; Seto, Yasuyuki; Yamatsuji, Tomoki; Naomoto, Yoshio; Shiraishi, Kenshiro; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Oka, Mikio; Pan, Linda; Hoffman, Eric W; Old, Lloyd J; Nakayama, Eiichi

2011-12-15

We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients. Copyright © 2011 UICC.

Nasal tolerance in experimental autoimmune myasthenia gravis (EAMG): induction of protective tolerance in primed animals

PubMed Central

Shi, F -D; Bai, X -F; LI, H -L; Huang, Y -M; Van Der Meide, P H; Link, H

1998-01-01

Nasal administration of μg doses of acetylcholine receptor (AChR) is effective in preventing the development of B cell-mediated EAMG in the Lewis rat, a model for human MG. In order to investigate whether nasal administration of AChR modulates ongoing EAMG, Lewis rats were treated nasally with AChR 2 weeks after immunization with AChR and Freund's complete adjuvant. Ten-fold higher amounts of AChR given nasally (600 μg/rat) were required to ameliorate the manifestations of EAMG compared with the amounts necessary for prevention of EAMG. In lymph node cells from rats receiving 600 μg/rat of AChR, AChR-induced proliferation and interferon-gamma (IFN-γ) secretion were reduced compared with control EAMG rats receiving PBS only. The anti-AChR antibodies in rats treated nasally with 600 μg/rat of AChR had lower affinity, reduced proportion of IgG2b and reduced capacity to induce AChR degradation. Numbers of AChR-reactive IFN-γ and tumour necrosis factor-alpha (TNF-α) mRNA-expressing lymph node cells from rats treated nasally with 600 μg/rat of AChR were suppressed, while IL-4, IL-10 and transforming growth factor-beta (TGF-β) mRNA-expressing cells were not affected. Collectively, these data indicate that nasal administration of AChR in ongoing EAMG induced selective suppression of Th1 functions, i.e. IFN-γ and IgG2b production, but no influence on Th2 cell functions. The impaired Th1 functions may result in the production of less myasthenic anti-AChR antibodies and contribute to the amelioration of EAMG severity in rats treated with AChR 600 μg/rat by the nasal route. PMID:9528890

Changes in Reactivity In Vitro of CD4+CD25+ and CD4+CD25− T Cell Subsets in Transplant Tolerance

PubMed Central

Hall, Bruce M.; Robinson, Catherine M.; Plain, Karren M.; Verma, Nirupama D.; Tran, Giang T.; Nomura, Masaru; Carter, Nicole; Boyd, Rochelle; Hodgkinson, Suzanne J.

2017-01-01

Transplant tolerance induced in adult animals is mediated by alloantigen-specific CD4+CD25+ T cells, yet in many models, proliferation of CD4+ T cells from hosts tolerant to specific-alloantigen in vitro is not impaired. To identify changes that may diagnose tolerance, changes in the patterns of proliferation of CD4+, CD4+CD25+, and CD4+CD25− T cells from DA rats tolerant to Piebald Virol Glaxo rat strain (PVG) cardiac allografts and from naïve DA rats were examined. Proliferation of CD4+ T cells from both naïve and tolerant hosts was similar to both PVG and Lewis stimulator cells. In mixed lymphocyte culture to PVG, proliferation of naïve CD4+CD25− T cells was greater than naïve CD4+ T cells. In contrast, proliferation of CD4+CD25− T cells from tolerant hosts to specific-donor PVG was not greater than CD4+ T cells, whereas their response to Lewis and self-DA was greater than CD4+ T cells. Paradoxically, CD4+CD25+ T cells from tolerant hosts did not proliferate to PVG, but did to Lewis, whereas naïve CD4+CD25+ T cells proliferate to both PVG and Lewis but not to self-DA. CD4+CD25+ T cells from tolerant, but not naïve hosts, expressed receptors for interferon (IFN)-γ and IL-5 and these cytokines promoted their proliferation to specific-alloantigen PVG but not to Lewis or self-DA. We identified several differences in the patterns of proliferation to specific-donor alloantigen between cells from tolerant and naïve hosts. Most relevant is that CD4+CD25+ T cells from tolerant hosts failed to proliferate or suppress to specific donor in the absence of either IFN-γ or IL-5. The proliferation to third-party and self of each cell population from tolerant and naïve hosts was similar and not affected by IFN-γ or IL-5. Our findings suggest CD4+CD25+ T cells that mediate transplant tolerance depend on IFN−γ or IL-5 from alloactivated Th1 and Th2 cells. PMID:28878770

Safety evaluation of a proprietary food-grade, dried fermentate preparation of Saccharomyces cerevisiae.

PubMed

Schauss, Alexander G; Glavits, R; Endres, John; Jensen, Gitte S; Clewell, Amy

2012-01-01

A safety evaluation was performed for EpiCor, a product produced by a proprietary fermentation process using Saccharomyces cerevisiae. Studies included the following assays: bacterial reverse mutation, mouse lymphoma cell mutagenicity, mitogenicity assay in human peripheral lymphocytes, and a cytochrome P450 ([CYP] CYP1A2 and CYP3A4) induction assessment as well as 14-day acute, 90-day subchronic, and 1-year chronic oral toxicity studies in rats. No evidence of genotoxicity or mitogenicity was seen in any of the in vitro or in vivo studies. The CYP assessment showed no interactions or inductions. No toxic clinical symptoms or histopathological lesions were observed in the acute, subchronic, or chronic oral toxicity studies in the rat. Results of the studies performed indicate that EpiCor does not possess genotoxic activity and has a low order of toxicity that is well tolerated when administered orally. The no observable adverse effect level (NOAEL) was 1500 mg/kg body weight (bw)/d for the 90-day study and 800 mg/kg bw/d for the 1 year study, for the highest doses tested.

What Are the Primary Limitations in B-Cell Affinity Maturation, and How Much Affinity Maturation Can We Drive with Vaccination? Breaking through Immunity's Glass Ceiling.

PubMed

Kelsoe, Garnett; Haynes, Barton F

2018-05-01

A key goal of HIV-1 vaccine development is the induction of broadly neutralizing antibodies (bnAbs) targeted to the vulnerable regions of the HIV envelope. BnAbs develop over time in ∼50% of HIV-1-infected individuals. However, to date, no vaccines have induced bnAbs and few or none of these vaccine-elicited HIV-1 antibodies carry the high frequencies of V(D)J mutations characteristic of bnAbs. Do the high frequencies of mutations characteristic of naturally induced bnAbs represent a fundamental barrier to the induction of bnAbs by vaccines? Recent studies suggest that high frequencies of V(D)J mutations can be achieved by serial vaccination strategies. Rather, it appears that, in the absence of HIV-1 infection, physiologic immune tolerance controls, including a germinal center process termed affinity reversion, may limit vaccine-driven bnAb development by clonal elimination or selecting for mutations incompatible with bnAb activity. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Induction of IAPP amyloid deposition and associated diabetic abnormalities by a prion-like mechanism

PubMed Central

Morales-Scheihing, Diego; Salvadores, Natalia; Moreno-Gonzalez, Ines; Gonzalez, Cesar; Shahnawaz, Mohammad

2017-01-01

Although a large proportion of patients with type 2 diabetes (T2D) accumulate misfolded aggregates composed of the islet amyloid polypeptide (IAPP), its role in the disease is unknown. Here, we show that pancreatic IAPP aggregates can promote the misfolding and aggregation of endogenous IAPP in islet cultures obtained from transgenic mouse or healthy human pancreas. Islet homogenates immunodepleted with anti-IAPP–specific antibodies were not able to induce IAPP aggregation. Importantly, intraperitoneal inoculation of pancreatic homogenates containing IAPP aggregates into transgenic mice expressing human IAPP dramatically accelerates IAPP amyloid deposition, which was accompanied by clinical abnormalities typical of T2D, including hyperglycemia, impaired glucose tolerance, and a substantial reduction on β cell number and mass. Finally, induction of IAPP deposition and diabetic abnormalities were also induced in vivo by administration of IAPP aggregates prepared in vitro using pure, synthetic IAPP. Our findings suggest that some of the pathologic and clinical alterations of T2D might be transmissible through a similar mechanism by which prions propagate in prion diseases. PMID:28765400

Single-cell analyses of transcriptional heterogeneity during drug tolerance transition in cancer cells by RNA sequencing.

PubMed

Lee, Mei-Chong Wendy; Lopez-Diaz, Fernando J; Khan, Shahid Yar; Tariq, Muhammad Akram; Dayn, Yelena; Vaske, Charles Joseph; Radenbaugh, Amie J; Kim, Hyunsung John; Emerson, Beverly M; Pourmand, Nader

2014-11-04

The acute cellular response to stress generates a subpopulation of reversibly stress-tolerant cells under conditions that are lethal to the majority of the population. Stress tolerance is attributed to heterogeneity of gene expression within the population to ensure survival of a minority. We performed whole transcriptome sequencing analyses of metastatic human breast cancer cells subjected to the chemotherapeutic agent paclitaxel at the single-cell and population levels. Here we show that specific transcriptional programs are enacted within untreated, stressed, and drug-tolerant cell groups while generating high heterogeneity between single cells within and between groups. We further demonstrate that drug-tolerant cells contain specific RNA variants residing in genes involved in microtubule organization and stabilization, as well as cell adhesion and cell surface signaling. In addition, the gene expression profile of drug-tolerant cells is similar to that of untreated cells within a few doublings. Thus, single-cell analyses reveal the dynamics of the stress response in terms of cell-specific RNA variants driving heterogeneity, the survival of a minority population through generation of specific RNA variants, and the efficient reconversion of stress-tolerant cells back to normalcy.

Single-cell analyses of transcriptional heterogeneity during drug tolerance transition in cancer cells by RNA sequencing

PubMed Central

Lee, Mei-Chong Wendy; Lopez-Diaz, Fernando J.; Khan, Shahid Yar; Tariq, Muhammad Akram; Dayn, Yelena; Vaske, Charles Joseph; Radenbaugh, Amie J.; Kim, Hyunsung John; Emerson, Beverly M.; Pourmand, Nader

2014-01-01

The acute cellular response to stress generates a subpopulation of reversibly stress-tolerant cells under conditions that are lethal to the majority of the population. Stress tolerance is attributed to heterogeneity of gene expression within the population to ensure survival of a minority. We performed whole transcriptome sequencing analyses of metastatic human breast cancer cells subjected to the chemotherapeutic agent paclitaxel at the single-cell and population levels. Here we show that specific transcriptional programs are enacted within untreated, stressed, and drug-tolerant cell groups while generating high heterogeneity between single cells within and between groups. We further demonstrate that drug-tolerant cells contain specific RNA variants residing in genes involved in microtubule organization and stabilization, as well as cell adhesion and cell surface signaling. In addition, the gene expression profile of drug-tolerant cells is similar to that of untreated cells within a few doublings. Thus, single-cell analyses reveal the dynamics of the stress response in terms of cell-specific RNA variants driving heterogeneity, the survival of a minority population through generation of specific RNA variants, and the efficient reconversion of stress-tolerant cells back to normalcy. PMID:25339441

The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

PubMed

Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

2013-10-15

During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.

Chlorophyll Fluorescence as a Possible Tool for Salinity Tolerance Screening in Barley (Hordeum vulgare L.).

PubMed Central

Belkhodja, R.; Morales, F.; Abadia, A.; Gomez-Aparisi, J.; Abadia, J.

1994-01-01

The application of chlorophyll fluorescence measurements to screening barley (Hordeum vulgare L.) genotypes for salinity tolerance has been investigated. Excised barley leaves were cut under water and incubated with the cut end immersed in water or in a 100-mM NaCl solution, either in the dark or in high light. Changes in rapid fluorescence kinetics occurred in excised barley leaves exposed to the saline solution only when the incubation was carried out in the presence of high light. Fluorescence changes consisted of decreases in the variable to maximum fluorescence ratio and in increases in the relative proportion of variable fluorescence leading to point I in the Kautsky fluorescence induction curve. These relative increases in fluorescence at point I appeared to arise from a delayed plastoquinone reoxidation in the dark, since they disappeared after short, far-red illumination, which is known to excite photosystem I preferentially. We show that a significant correlation existed between some fluorescence parameters, measured after a combined salt and high-light treatment, and other independent measurements of salinity tolerance. These results suggest that chlorophyll fluorescence, and especially the relative fluorescence at point I in the Kautsky fluorescence induction curve, could be used for the screening of barley genotypes for salinity tolerance. PMID:12232117

Effect of physical training in cool and hot environments on +Gz acceleration tolerance in women

NASA Technical Reports Server (NTRS)

Brock, P. J.; Sciaraffa, D.; Greenleaf, J. E.

1982-01-01

Acceleration tolerance, plasma volume, and maximal oxygen uptake were measured in 15 healthy women before and after submaximal isotonic exercise training periods in cool and hot environments. The women were divided on the basis of age, maximal oxygen uptake, and +Gz tolerance into three groups: a group that exercised in heat (40.6 C), a group that exercised at a lower temperature (18.7 C), and a sedentary control group that functioned in the cool environment. There was no significant change in the +Gz tolerance in any group after training, and terminal heart rates were similar within each group. It is concluded that induction of moderate acclimation responses without increases in sweat rate or resting plasma volume has no influence on +Gz acceleration tolerance in women.

Ubc9 is required for damage-tolerance and damage-induced interchromosomal homologous recombination in S. cerevisiae.

PubMed

Maeda, Daisuke; Seki, Masayuki; Onoda, Fumitoshi; Branzei, Dana; Kawabe, Yoh-Ichi; Enomoto, Takemi

2004-03-04

Ubc9 is an enzyme involved in the conjugation of small ubiquitin related modifier (SUMO) to target proteins. A Saccharomyces cerevisiae ubc9 temperature sensitive (ts) mutant showed higher sensitivity to various DNA damaging agents such as methylmethanesulfonate (MMS) and UV at a semi-permissive temperature than wild-type cells. The sensitivity of ubc9ts cells was not suppressed by the introduction of a mutated UBC9 gene, UBC9-C93S, whose product is unable to covalently bind to SUMO and consequently fails to conjugate SUMO to target proteins. Diploid ubc9ts cells were more sensitive to various DNA damaging agents than haploid ubc9ts cells suggesting the involvement of homologous recombination in the sensitivity of ubc9ts cells. The frequency of interchromosomal recombination between heteroalleles, his1-1/his1-7 loci, in wild-type cells was remarkably increased upon exposure to MMS or UV. Although the frequency of spontaneous interchromosomal recombination between the heteroalleles in ubc9ts cells was almost the same as that of wild-type cells, no induction of interchromosomal recombination was observed in ubc9ts cells upon exposure to MMS or UV. Copyright 2003 Elsevier B.V.

Ruminative and mindful self-focused attention in borderline personality disorder.

PubMed

Sauer, Shannon E; Baer, Ruth A

2012-10-01

The current study investigated the short-term effects of mindful and ruminative forms of self-focused attention on a behavioral measure of distress tolerance in individuals with borderline personality disorder (BPD) who had completed an angry mood induction. Participants included 40 individuals who met criteria for BPD and were currently involved in mental health treatment. Each completed an individual 1-hr session. Following an angry mood induction, each participant was randomly assigned to engage in ruminative or mindful self-focus for several minutes. All participants then completed the computerized Paced Auditory Serial Addition Test (PASAT-C), a behavioral measure of willingness to tolerate distress in the service of goal-directed behavior. The mindfulness group persisted significantly longer than the rumination group on the distress tolerance task and reported significantly lower levels of anger following the self-focus period. Results are consistent with previous studies in suggesting that distinct forms of self-focused attention have distinct outcomes and that, for people with BPD, mindful self-observation is an adaptive alternative to rumination when feeling angry. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Notes on the Problems of the Transplantation of Kidneys in Dogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puza, A.; Drahovsky, V.; Neubauer, E.

1963-01-01

In a group of 29 mongrel dogs kidney homotransplantation was performed. In five dogs an autograft was performed to check the suitability of the surgical technique. In the remaining 24 dogs kidney homografts were carried out, Five dogs served as controls; in these animals the functioning of the homografted kidney stopped after 8 days on the average, In 12 animals an attempt at the induction of immunological tolerance by exsanguinotransfusion, whole-body irradiation and 6-MP-administration was made. Induction of immunological tolerance by total exsanguinotransfusion immediately after birth may render possible a successful homograft even in adult life. The transplanted organ thenmore » exhibits a permanent take and takes over the function of the recipient's removed kidneys. One dog is alive with its single kidney homograft after almost two years. 6-MP administration may lead to such a degree of induced tolerance that the function of a kidney homograft is prolonged by a factor of two to three. Whole-body irradiation within a range of 400 rad (Co 60 source) does not significantly prolong homograft survival.« less

Immune Tolerance in Multiple Sclerosis

PubMed Central

Goverman, Joan M.

2011-01-01

Summary Multiple sclerosis is believed to be mediated by T cells specific for myelin antigens that circulate harmlessly in the periphery of healthy individuals until they are erroneously by an environmental stimulus. Upon activation, the T cells enter the central nervous system and orchestrate an immune response against myelin. To understand the initial steps in the pathogenesis of multiple sclerosis, it is important to identify the mechanisms that maintain T-cell tolerance to myelin antigens and to understand how some myelin-specific T cells escape tolerance and what conditions lead to their activation. Central tolerance strongly shapes the peripheral repertoire of myelin-specific T cells, as most myelin-specific T cells are eliminated by clonal deletion in the thymus. Self-reactive T cells that escape central tolerance are generally capable only of low-avidity interactions with antigen-presenting cells. Despite the low avidity of these interactions, peripheral tolerance mechanisms are required to prevent spontaneous autoimmunity. Multiple peripheral tolerance mechanisms for myelin-specific T cells have been indentified, the most important of which appears to be regulatory T cells. While most studies have focused on CD4+ myelin-specific T cells, interesting differences in tolerance mechanisms and the conditions that abrogate these mechanisms have recently been described for CD8+ myelin-specific T cells. PMID:21488900

Lessons from reproductive immunology for other fields of immunology and clinical approaches.

PubMed

Markert, Udo R; Fitzgerald, Justine S; Seyfarth, Lydia; Heinzelmann, Joana; Varosi, Frauke; Voigt, Sandra; Schleussner, Ekkehard; Seewald, Hans-Joachim

2005-01-01

Reproduction is indispensable to evolution and, thus, life. Nonetheless, it overcomes common rules known to established life. Immunology of reproduction, and especially the tolerance of two genetically distinct organisms and their fruitful symbiosis, is one of the most imposing paradox of life. Mechanisms, which are physiologically used for induction of said tolerance, are frequently abused by pathogens or tumors intending to escape the host's immune response. Understanding the regulation of immune responses in pregnancy and the invasion of allogeneic fetus-derived trophoblast cells into the decidua may lead to new therapeutic concepts. In transplantation, knowledge concerning local physiological immunotolerance may be useful for the development of new therapies, which do not require a general immune suppression of the patient. In immunological disorders, such as autoimmune diseases or allergies, immune deviations occur which are either prevented during pregnancy or have parallels to pregnancy. Vice versa, lessons from other fields of immunology may also offer new notions for the comprehension of reproductive immunology and may lead to new therapies for the treatment of pregnancy-related problems.

Comparative transcriptome analysis of differentially expressed genes in foxtail millet (Setaria italica L.) during dehydration stress.

PubMed

Lata, Charu; Sahu, Pranav Pankaj; Prasad, Manoj

2010-03-19

Dehydration stress is one of the most important abiotic stresses that adversely influence crop growth and productivity. With the aim to understand the molecular mechanisms underlying dehydration stress tolerance in foxtail millet (Setaria italica L.), a drought tolerant crop, we examined its transcriptome changes at two time points (early and late) of dehydration stress. Two suppression subtractive hybridization (SSH) forward libraries were constructed from 21-day old seedlings of tolerant cv. Prasad at 0.5 and 6h PEG-induced dehydration stress. A total of 327 unique ESTs were identified from both libraries and were classified into 11 different categories according to their putative functions. The plant response against dehydration stress was complex, representing major transcripts involved in metabolism, stress, signaling, transcription regulation, translation and proteolysis. By Reverse Northern (RN) technique we identified the differential expression pattern of 327 transcripts, 86 (about 26%) of which showed > or = 1.7-fold induction. Further the obtained results were validated by quantitative real-time PCR (qRT-PCR) to have a comparative expression profiling of randomly chosen 9 up-regulated transcripts (> or =2.5 fold induction) between cv. Prasad (tolerant) and cv. Lepakshi (sensitive) upon dehydration stress. These transcripts showed a differential expression pattern in both cultivars at different time points of stress treatment as analyzed by qRT-PCR. The possible relationship of the identified transcripts with dehydration tolerance mechanism is discussed. Copyright 2010 Elsevier Inc. All rights reserved.

Roles of thioredoxin in nitric oxide-dependent preconditioning-induced tolerance against MPTP neurotoxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiueh, C.C.; Andoh, Tsugunobu; Chock, P. Boon

2005-09-01

Hormesis, a stress tolerance, can be induced by ischemic preconditioning stress. In addition to preconditioning, it may be induced by other means, such as gas anesthetics. Preconditioning mechanisms, which may be mediated by reprogramming survival genes and proteins, are obscure. A known neurotoxicant, 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), causes less neurotoxicity in the mice that are preconditioned. Pharmacological evidences suggest that the signaling pathway of {center_dot}NO-cGMP-PKG (protein kinase G) may mediate preconditioning phenomenon. We developed a human SH-SY5Y cell model for investigating {sup {center_dot}}NO-mediated signaling pathway, gene regulation, and protein expression following a sublethal preconditioning stress caused by a brief 2-h serum deprivation.more » Preconditioned human SH-SY5Y cells are more resistant against severe oxidative stress and apoptosis caused by lethal serum deprivation and 1-mehtyl-4-phenylpyridinium (MPP{sup +}). Both sublethal and lethal oxidative stress caused by serum withdrawal increased neuronal nitric oxide synthase (nNOS/NOS1) expression and {sup {center_dot}}NO levels to a similar extent. In addition to free radical scavengers, inhibition of nNOS, guanylyl cyclase, and PKG blocks hormesis induced by preconditioning. S-nitrosothiols and 6-Br-cGMP produce a cytoprotection mimicking the action of preconditioning tolerance. There are two distinct cGMP-mediated survival pathways: (i) the up-regulation of a redox protein thioredoxin (Trx) for elevating mitochondrial levels of antioxidant protein Mn superoxide dismutase (MnSOD) and antiapoptotic protein Bcl-2, and (ii) the activation of mitochondrial ATP-sensitive potassium channels [K(ATP)]. Preconditioning induction of Trx increased tolerance against MPP{sup +}, which was blocked by Trx mRNA antisense oligonucleotide and Trx reductase inhibitor. It is concluded that Trx plays a pivotal role in {sup {center_dot}}NO-dependent preconditioning hormesis against MPTP/MPP{sup +}.« less

Biomarkers of tolerance: searching for the hidden phenotype.

PubMed

Perucha, Esperanza; Rebollo-Mesa, Irene; Sagoo, Pervinder; Hernandez-Fuentes, Maria P

2011-08-01

Induction of transplantation tolerance remains the ideal long-term clinical and logistic solution to the current challenges facing the management of renal allograft recipients. In this review, we describe the recent studies and advances made in identifying biomarkers of renal transplant tolerance, from study inceptions, to the lessons learned and their implications for current and future studies with the same goal. With the age of biomarker discovery entering a new dimension of high-throughput technologies, here we also review the current approaches, developments, and pitfalls faced in the subsequent statistical analysis required to identify valid biomarker candidates.

Natural genetic variation of freezing tolerance in Arabidopsis.

PubMed

Hannah, Matthew A; Wiese, Dana; Freund, Susanne; Fiehn, Oliver; Heyer, Arnd G; Hincha, Dirk K

2006-09-01

Low temperature is a primary determinant of plant growth and survival. Using accessions of Arabidopsis (Arabidopsis thaliana) originating from Scandinavia to the Cape Verde Islands, we show that freezing tolerance of natural accessions correlates with habitat winter temperatures, identifying low temperature as an important selective pressure for Arabidopsis. Combined metabolite and transcript profiling show that during cold exposure, global changes of transcripts, but not of metabolites, correlate with the ability of Arabidopsis to cold acclimate. There are, however, metabolites and transcripts, including several transcription factors, that correlate with freezing tolerance, indicating regulatory pathways that may be of primary importance for this trait. These data identify that enhanced freezing tolerance is associated with the down-regulation of photosynthesis and hormonal responses and the induction of flavonoid metabolism, provide evidence for naturally increased nonacclimated freezing tolerance due to the constitutive activation of the C-repeat binding factors pathway, and identify candidate transcriptional regulators that correlate with freezing tolerance.

Variation in sulfide tolerance of photosystem II in phylogenetically diverse cyanobacteria from sulfidic habitats

NASA Technical Reports Server (NTRS)

Miller, Scott R.; Bebout, Brad M.

2004-01-01

Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor of oxygenic photosynthesis. Cyanobacteria from sulfidic habitats were found to be phylogenetically diverse and exhibited an approximately 50-fold variation in photosystem II performance in the presence of sulfide. Whereas the degree of tolerance was positively correlated with sulfide levels in the environment, a strain's phenotype could not be predicted from the tolerance of its closest relatives. These observations suggest that sulfide tolerance is a dynamic trait primarily shaped by environmental variation. Despite differences in absolute tolerance, similarities among strains in the effects of sulfide on chlorophyll fluorescence induction indicated a common mode of toxicity. Based on similarities with treatments known to disrupt the oxygen-evolving complex, it was concluded that sulfide toxicity resulted from inhibition of the donor side of photosystem II.

Neurogenic differentiation of dental pulp stem cells to neuron-like cells in dopaminergic and motor neuronal inductive media.

PubMed

Chang, Chia-Chieh; Chang, Kai-Chun; Tsai, Shang-Jye; Chang, Hao-Hueng; Lin, Chun-Pin

2014-12-01

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. The aim of this study was to evaluate the efficacy of dopaminergic and motor neuronal inductive media on transdifferentiation of human DPSCs (hDPSCs) into neuron-like cells. Isolation, cultivation, and identification of hDPSCs were performed with morphological analyses and flow cytometry. The proliferation potential of DPSCs was evaluated with an XTT [(2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide)] assay. Media for the induction of dopaminergic and spinal motor neuronal differentiation were prepared. The efficacy of neural induction was evaluated by detecting the expression of neuron cell-specific cell markers in DPSCs by immunocytochemistry and quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). In the XTT assay, there was a 2.6- or 2-fold decrease in DPSCs cultured in dopaminergic or motor neuronal inductive media, respectively. The proportions of βIII-tubulin (βIII-tub), glial fibrillary acidic protein (GFAP), and oligodendrocyte (O1)-positive cells were significantly higher in DPSCs cultured in both neuronal inductive media compared with those cultured in control media. Furthermore, hDPSC-derived dopaminergic and spinal motor neuron cells after induction expressed a higher density of neuron cell markers than those before induction. These findings suggest that in response to the neuronal inductive stimuli, a greater proportion of DPSCs stop proliferation and acquire a phenotype resembling mature neurons. Such neural crest-derived adult DPSCs may provide an alternative stem cell source for therapy-based treatments of neuronal disorders and injury. Copyright © 2014. Published by Elsevier B.V.

The benzomorphan-based LP1 ligand is a suitable MOR/DOR agonist for chronic pain treatment.

PubMed

Pasquinucci, Lorella; Parenti, Carmela; Turnaturi, Rita; Aricò, Giuseppina; Marrazzo, Agostino; Prezzavento, Orazio; Ronsisvalle, Simone; Georgoussi, Zafiroula; Fourla, Danai-Dionysia; Scoto, Giovanna M; Ronsisvalle, Giuseppe

2012-01-02

Powerful analgesics relieve pain primarily through activating mu opioid receptor (MOR), but the long-term use of MOR agonists, such as morphine, is limited by the rapid development of tolerance. Recently, it has been observed that simultaneous stimulation of the delta opioid receptor (DOR) and MOR limits the incidence of tolerance induced by MOR agonists. 3-[(2R,6R,11R)-8-hydroxy-6,11-dimethyl-1,4,5,6-tetrahydro-2,6-methano-3-benzazocin-3(2H)-yl]-N-phenylpropanamide (LP1) is a centrally acting agent with antinociceptive activity comparable to morphine and is able to bind and activate MOR and DOR. The aim of this work was to evaluate and compare the induction of tolerance to antinociceptive effects from treatment with LP1 and morphine. Here, we evaluated the pharmacological effects of LP1 administered at a dose of 4 mg/kg subcutaneously (s.c.) twice per day for 9 days to male Sprague-Dawley rats. In addition, the LP1 mechanism of action was assessed by measurement of LP1-induced [(35)S]GTPγS binding to the MOR and DOR. Data obtained from the radiant heat tail flick test showed that LP1 maintained its antinociceptive profile until the ninth day, while tolerance to morphine (10mg/kg s.c. twice per day) was observed on day 3. Moreover, LP1 significantly enhanced [(35)S]GTPγS binding in the membranes of HEK293 cells expressing either the MOR or the DOR. LP1 is a novel analgesic agent for chronic pain treatment, and its low tolerance-inducing capability may be correlated with its ability to bind both the MOR and DOR. Copyright © 2011 Elsevier Inc. All rights reserved.

Oral Sulforaphane increases Phase II antioxidant enzymes in the human upper airway

PubMed Central

Riedl, Marc A.; Saxon, Andrew; Diaz-Sanchez, David

2009-01-01

Background Cellular oxidative stress is an important factor in asthma and is thought to be the principle mechanism by which oxidant pollutants such as ozone and particulates mediate their pro-inflammatory effects. Endogenous Phase II enzymes abrogate oxidative stress through the scavenging of reactive oxygen species and metabolism of reactive chemicals. Objective We conducted a placebo-controlled dose escalation trial to investigate the in vivo effects of sulforaphane, a naturally occurring potent inducer of Phase II enzymes, on the expression of glutathione-s-transferase M1 (GSTM1), glutathione-s-transferase P1 (GSTP1), NADPH quinone oxidoreductase (NQO1), and hemoxygenase-1 (HO-1) in the upper airway of human subjects. Methods Study subjects consumed oral sulforaphane doses contained in a standardized broccoli sprout homogenate (BSH). RNA expression for selected Phase II enzymes was measured in nasal lavage cells by RT-PCR before and after sulforaphane dosing. Results All subjects tolerated oral sulforaphane dosing without significant adverse events. Increased Phase II enzyme expression in nasal lavage cells occurred in a dose-dependent manner with maximal enzyme induction observed at the highest dose of 200 grams broccoli sprouts prepared as BSH. Significant increases were seen in all sentinel Phase II enzymes RNA expression compared to baseline. Phase II enzyme induction was not seen with ingestion of non-sulforaphane containing alfalfa sprouts. Conclusion Oral sulforaphane safely and effectively induces mucosal Phase II enzyme expression in the upper airway of human subjects. This study demonstrates the potential of antioxidant Phase II enzymes induction in the human airway as a strategy to reduce the inflammatory effects of oxidative stress. Clinical Implications This study demonstrates the potential of enhancement of Phase II enzyme expression as a novel therapeutic strategy for oxidant induced airway disease. Capsule Summary A placebo-controlled dose escalation trial demonstrated that naturally occurring sulforaphane from broccoli sprouts can induce a potent increase in antioxidant Phase II enzymes in airway cells. PMID:19028145

The ratio of cancer cells to stroma after induction therapy in the treatment of non-small cell lung cancer.

PubMed

Goto, Masaki; Naito, Masahito; Saruwatari, Koichi; Hisakane, Kakeru; Kojima, Motohiro; Fujii, Satoshi; Kuwata, Takeshi; Ochiai, Atsushi; Nomura, Shogo; Aokage, Keiju; Hishida, Tomoyuki; Yoshida, Junji; Yokoi, Kohei; Tsuboi, Masahiro; Ishii, Genichiro

2017-02-01

Induction therapy induces degenerative changes of various degrees in both cancerous and non-cancerous cells of non-small cell lung cancer (NSCLC). The effect of induction therapy on histological characteristics, in particular the ratio of residual cancer cells to non-cancerous components, is unknown. Seventy-four NSCLC patients treated with induction therapy followed by surgery were enrolled. Residual cancer cells were identified using anti-pan-cytokeratin antibody (AE1/AE3). We analyzed and quantified the following three factors via digital image analysis; (1) the tumor area containing cancer cells and non-cancerous components (TA), (2) the total area of AE1/AE3 positive cancer cells (TACC), (3) the percentage of TACC to TA (%TACC). These factors were also analyzed in a matched control group (surgery alone, n = 80). The median TACC of the induction therapy group was significantly lower than that of the control group (p < 0.01). In addition, the median %TACC of the induction therapy group (5.9 %) was significantly lower than that of the control group (58.6 %) (p < 0.01). TACC had a strong positive correlation with TA in the control group (r = 0.93), but not in the induction therapy group. Conversely, TACC had a strong positive correlation with %TACC in the induction therapy group (r = 0.95), but not in the control group. Unlike the control group, the smaller the total area of residual cancer cells, the higher residual tumor contained non-cancerous components in the induction group, which may be the characteristic histological feature of NSCLC after induction therapy.

Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana

PubMed Central

Ledger, Thomas; Rojas, Sandy; Timmermann, Tania; Pinedo, Ignacio; Poupin, María J.; Garrido, Tatiana; Richter, Pablo; Tamayo, Javier

2016-01-01

Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic stress tolerance by a Paraburkholderia species. PMID:27909432

Tolerance in Nonhuman Primates by Delayed Mixed Chimerism

DTIC Science & Technology

2017-12-01

person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control ...induction of mixed chimerism in a non -human primate (NHP) model. This approach, in contrast to protocols which have already reached clinical trials...principle of delayed induction of mixed chimerism in a non -human primate (NHP) model. This approach, in contrast to protocols which have already reached

An inductance Fourier decomposition-based current-hysteresis control strategy for switched reluctance motors

NASA Astrophysics Data System (ADS)

Hua, Wei; Qi, Ji; Jia, Meng

2017-05-01

Switched reluctance machines (SRMs) have attracted extensive attentions due to the inherent advantages, including simple and robust structure, low cost, excellent fault-tolerance and wide speed range, etc. However, one of the bottlenecks limiting the SRMs for further applications is its unfavorable torque ripple, and consequently noise and vibration due to the unique doubly-salient structure and pulse-current-based power supply method. In this paper, an inductance Fourier decomposition-based current-hysteresis-control (IFD-CHC) strategy is proposed to reduce torque ripple of SRMs. After obtaining a nonlinear inductance-current-position model based Fourier decomposition, reference currents can be calculated by reference torque and the derived inductance model. Both the simulations and experimental results confirm the effectiveness of the proposed strategy.

Positive and negative regulation of T cell responses by fibroblastic reticular cells within paracortical regions of lymph nodes

PubMed Central

Siegert, Stefanie; Luther, Sanjiv A.

2012-01-01

Fibroblastic reticular cells (FRC) form the structural backbone of the T cell rich zones in secondary lymphoid organs (SLO), but also actively influence the adaptive immune response. They provide a guidance path for immigrating T lymphocytes and dendritic cells (DC) and are the main local source of the cytokines CCL19, CCL21, and IL-7, all of which are thought to positively regulate T cell homeostasis and T cell interactions with DC. Recently, FRC in lymph nodes (LN) were also described to negatively regulate T cell responses in two distinct ways. During homeostasis they express and present a range of peripheral tissue antigens, thereby participating in peripheral tolerance induction of self-reactive CD8+ T cells. During acute inflammation T cells responding to foreign antigens presented on DC very quickly release pro-inflammatory cytokines such as interferon γ. These cytokines are sensed by FRC which transiently produce nitric oxide (NO) gas dampening the proliferation of neighboring T cells in a non-cognate fashion. In summary, we propose a model in which FRC engage in a bidirectional crosstalk with both DC and T cells to increase the efficiency of the T cell response. However, during an acute response, FRC limit excessive expansion and inflammatory activity of antigen-specific T cells. This negative feedback loop may help to maintain tissue integrity and function during rapid organ growth. PMID:22973278

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatton, Matthew; Nankivell, Matthew, E-mail: mn@ctu.mrc.ac.uk; Lyn, Ethan

Purpose: Recent clinical trials and meta-analyses have shown that both CHART (continuous hyperfractionated accelerated radiation therapy) and induction chemotherapy offer a survival advantage over conventional radical radiotherapy for patients with inoperable non-small cell-lung cancer (NSCLC). This multicenter randomized controlled trial (INCH) was set up to assess the value of giving induction chemotherapy before CHART. Methods and Materials: Patients with histologically confirmed, inoperable, Stage I-III NSCLC were randomized to induction chemotherapy (ICT) (three cycles of cisplatin-based chemotherapy followed by CHART) or CHART alone. Results: Forty-six patients were randomized (23 in each treatment arm) from 9 UK centers. As a result ofmore » poor accrual, the trial was closed in December 2007. Twenty-eight patients were male, 28 had squamous cell histology, 34 were Stage IIIA or IIIB, and all baseline characteristics were well balanced between the two treatment arms. Seventeen (74%) of the 23 ICT patients completed the three cycles of chemotherapy. All 42 (22 CHART + 20 ICT) patients who received CHART completed the prescribed treatment. Median survival was 17 months in the CHART arm and 25 months in the ICT arm (hazard ratio of 0.60 [95% CI 0.31-1.16], p = 0.127). Grade 3 or 4 adverse events (mainly fatigue, dysphagia, breathlessness, and anorexia) were reported for 13 (57%) CHART and 13 (65%) ICT patients. Conclusions: This small randomized trial indicates that ICT followed by CHART is feasible and well tolerated. Despite closing early because of poor accrual, and so failing to show clear evidence of a survival benefit for the additional chemotherapy, the results suggest that CHART, and ICT before CHART, remain important options for the treatment of inoperable NSCLC and deserve further study.« less

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study

PubMed Central

Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

2016-01-01

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201’s cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201. PMID:27626799

Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study.

PubMed

Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

2016-01-01

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201's cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201.

Treatment of dextran sodium sulfate-induced experimental colitis by adoptive transfer of peritoneal cells

PubMed Central

Liu, Ting; Ren, Jun; Wang, Wei; Wei, Xia-wei; Shen, Guo-bo; Liu, Yan-tong; Luo, Min; Xu, Guang-chao; Shao, Bin; Deng, Sen-yi; He, Zhi-yao; Liang, Xiao; Liu, Yu; Wen, Yan-Zhu; Xiang, Rong; Yang, Li; Deng, Hong-xin; Wei, Yu-quan

2015-01-01

The adoptive transfer of the natural regulatory B cells and macrophages should be a useful treatment for inflammation and autoimmune disease. However, it is usually difficult to isolate these cells from the tissues and expand them. Here, we investigated the feasibility of adoptively transferring peritoneal cells (PCs) as a treatment for DSS-induced colitis. We found that peritoneal cavity can provide an easily accessible site for harvesting enough number of PCs, namely, two-dose PCs for the treatment from a mouse in one operation. Adoptive therapy of these cells from healthy mice or those with disease is effectively in reducing the disease activity score. The natural B cells and macrophages of the infused PCs can selectively migrate to lesion sites and regulate the expression of Stat3, NF−κB, Smad3 and Smad7. Additionally, PCs exert dual activity of IL-10 and TGF-β secreted spontaneously by both peritoneal B cells and macrophages, which in turn enhance the induction of regulatory B cells and Macrophages in microenvironment of inflammation. Moreover, PCs can re-establish immunological tolerance in the OVA-immunized mice. Thus, our findings provide a new strategy for colitis therapy and could be of importance in additional exploration of other inflammation and autoimmune diseases therapy. PMID:26565726

Reduced risk of apoptosis: mechanisms of stress responses.

PubMed

Milisav, Irina; Poljšak, Borut; Ribarič, Samo

2017-02-01

Apoptosis signaling pathways are integrated into a wider network of interconnected apoptotic and anti-apoptotic pathways that regulate a broad range of cell responses from cell death to growth, development and stress responses. An important trigger for anti- or pro-apoptotic cell responses are different forms of stress including hypoxia, energy deprivation, DNA damage or inflammation. Stress duration and intensity determine whether the cell's response will be improved cell survival, due to stress adaptation, or cell death by apoptosis, necrosis or autophagy. Although the interplay between enhanced stress tolerance and modulation of apoptosis triggering is not yet fully understood, there is a substantial body of experimental evidence demonstrating that apoptosis and anti-apoptosis signaling pathways can be manipulated to trigger or delay apoptosis in vitro or in vivo. Anti-apoptotic strategies cover a broad range of approaches. These interventions include mediators that prevent apoptosis (trophic factors and cytokines), apoptosis inhibition (caspase inhibition, stimulation of anti-apoptotic or inhibition of pro-apoptotic proteins and elimination of apoptotic stimulus), adaptive stress responses (induction of maintenance and repair, caspase inactivation) and cell-cell interactions (blocking engulfment and modified micro environment). There is a consensus that preclinical efficacy and safety evaluations of anti-apoptotic strategies should be performed with protocols that simulate as closely as possible the effects of aging, gender, risk factors, comorbidities and co-medications.

A Double-Blind, Double-Dummy, Flexible-Design Randomized Multicenter Trial: Early Safety of Single- Versus Divided-Dose Rabbit Anti-Thymocyte Globulin Induction in Renal Transplantation.

PubMed

Stevens, R B; Wrenshall, L E; Miles, C D; Farney, A C; Jie, T; Sandoz, J P; Rigley, T H; Osama Gaber, A

2016-06-01

A previous nonblinded, randomized, single-center renal transplantation trial of single-dose rabbit anti-thymocyte globulin induction (SD-rATG) showed improved efficacy compared with conventional divided-dose (DD-rATG) administration. The present multicenter, double-blind/double-dummy STAT trial (Single dose vs. Traditional Administration of Thymoglobulin) evaluated SD-rATG versus DD-rATG induction for noninferiority in early (7-day) safety and tolerability. Ninety-five patients (randomized 1:1) received 6 mg/kg SD-rATG or 1.5 mg/kg/dose DD-rATG, with tacrolimus-mycophenolate maintenance immunosuppression. The primary end point was a composite of fever, hypoxia, hypotension, cardiac complications, and delayed graft function. Secondary end points included 12-month patient survival, graft survival, and rejection. Target enrollment was 165 patients with an interim analysis scheduled after 80 patients. Interim analysis showed primary end point noninferiority of SD-rATG induction (p = 0.6), and a conditional probability of <1.73% of continued enrollment producing a significant difference (futility analysis), leading to early trial termination. Final analysis (95 patients) showed no differences in occurrence of primary end point events (p = 0.58) or patients with no, one, or more than one event (p = 0.81), or rejection, graft, or patient survival (p = 0.78, 0.47, and 0.35, respectively). In this rigorously blinded trial in adult renal transplantation, we have shown SD-rATG induction to be noninferior to DD-rATG induction in early tolerability and equivalent in 12-month safety. (Clinical Trials.gov #NCT00906204.). © Copyright 2016 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of the American Society of Transplantation and the American Society of Transplant Surgeons.

Xenopus tropicalis transgenic lines and their use in the study of embryonic induction.

PubMed

Hirsch, Nicolas; Zimmerman, Lyle B; Gray, Jessica; Chae, Jeiwook; Curran, Kristen L; Fisher, Marilyn; Ogino, Hajime; Grainger, Robert M

2002-12-01

For over a century, amphibian embryos have been a source of significant insight into developmental mechanisms, including fundamental discoveries about the process of induction. The recently developed transgenesis for Xenopus offers new approaches to these poorly understood processes, particularly when undertaken in the quickly maturing species Xenopus tropicalis, which greatly facilitates establishment of permanent transgenic lines. Several X. tropicalis transgenic lines have now been generated, and experiments demonstrating the value of these lines to study induction in embryonic tissue recombinants and explants are presented here. A revised protocol for transgenesis in X. tropicalis resulting in a significant increase in the percentage of transgenic animals that reach adulthood is presented, as well as improvements in tadpole and froglet husbandry, which have facilitated the raising of large numbers of adults. Working transgenic populations have been rapidly expanded, and some transgenes have been bred to homozygosity. Established lines include those bearing the promoter regions of Pax-6, Otx-2, Rx, and EF1alpha coupled to fluorescent reporter genes. Multireporter lines combining, in a single animal, up to three gene promoters coupled to different fluorescent reporters have also been established. The value of X. tropicalis transgenic lines for the study of induction is demonstrated by showing activation of Pax-6 by noggin treatment of Pax-6/GFP transgenic animal caps, illustrating how reporter lines allow a rapid, in vivo assay for an inductive response. An experiment showing lens induction in gamma-crystallin/GFP transgenic lens ectoderm when it is recombined with mouse optic vesicle demonstrates conservation of inducing signals from amphibians and mammals. It also shows how the warmer culture temperatures tolerated by X. tropicalis embryos can be used in assays of factors produced by mammalian cells and tissues. The many applications of transgenic reporter lines and other lines designed to target gene expression in particular tissues promise to bring significant new insights to the classic issues first defined in amphibian systems. Copyright 2002 Wiley-Liss, Inc.

Diagnostic value of tolerance-related gene expression measured in the recipient alloantigen-reactive T cell fraction.

PubMed

Lim, Dong-Gyun; Park, Youn-Hee; Kim, Sung-Eun; Jeong, Seong-Hee; Kim, Song-Cheol

2013-08-01

The efficient development of tolerance-inducing therapies and safe reduction of immunosuppression should be supported by early diagnosis and prediction of tolerance in transplantation. Using mouse models of donor-specific tolerance to allogeneic skin and islet grafts we tested whether measurement of tolerance-related gene expression in their alloantigen-reactive peripheral T cell fraction efficiently reflected the tolerance status of recipients. We found that Foxp3, Nrn1, and Klrg1 were preferentially expressed in conditions of tolerance compared with rejection or unmanipulated controls if their expression is measured in CD69(+) T cells prepared from coculture of recipient peripheral T cells and donor antigen-presenting cells. The same pattern of gene expression was observed in recipients grafted with either skin or islets, recipients of different genetic origins, and even those taking immunosuppressive drugs. These findings suggest that the expression of tolerance-related genes in the alloantigen-reactive T cell fraction could be used to detect tolerance in the clinic. Copyright © 2013 Elsevier Inc. All rights reserved.

Inhibition of allergic encephalomyelitis in marmosets by vaccination with recombinant vaccinia virus encoding for myelin basic protein.

PubMed

Genain, C P; Gritz, L; Joshi, N; Panicali, D; Davis, R L; Whitaker, J N; Letvin, N L; Hauser, S L

1997-11-01

A primary demyelinating form of experimental allergic encephalomyelitis (EAE) resembling human multiple sclerosis (MS) occurs in Callithrix jacchus marmosets following immunization with human white matter. Participation of a T-cell immune response against myelin basic protein (MBP) in this disease model is supported by observations of increased reactivity against MBP in PBMC and of adoptive transfer of an inflammatory form of EAE by MBP-reactive T-cells. To evaluate the effects of ectopic presentation of MBP on marmoset EAE, animals were vaccinated prior to induction of EAE by subcutaneous injection of attenuated strains of vaccinia virus genetically engineered to contain either the entire coding sequence for human MBP (vT15) or the equine herpes virus glycoprotein gH gene (vAbT249). Vaccination with vT15 was followed by transient cytoplasmic and surface membrane expression of MBP in circulating PBMC (15-45 days). The onset of clinical EAE after immunization (pi) was markedly delayed in vT15-vaccinated animals (37-97 days pi, n = 4) compared to vAbT249-vaccinated controls (14-18 days pi, n = 3). Proliferative responses against MBP but not against vaccinia antigens or phytohemagglutinin were suppressed in protected animals. Thus, development of attenuated live viruses carrying genes for myelin antigens could be useful for induction of immunologic tolerance and for modulation of autoimmune demyelination.

Effect of airway clearance techniques on the efficacy of the sputum induction procedure.

PubMed

Elkins, M R; Lane, T; Goldberg, H; Pagliuso, J; Garske, L A; Hector, E; Marchetto, L; Alison, J A; Bye, P T P

2005-11-01

Sputum induction is used in the early identification of tuberculosis (TB) and pneumocystis infections of the lung. Although manual physiotherapy techniques to clear the airways are often incorporated in the sputum induction procedure, their efficacy in this setting is unknown. This randomised, crossover trial enrolled adults referred for sputum induction for suspected TB and pneumocystis infections of the lung. All participants underwent two sputum induction procedures, inhaling 3% saline via ultrasonic nebuliser. During one randomly allocated procedure, airway clearance techniques (chest wall percussion, vibration, huffing) were incorporated. In total, 59 participants completed the trial. The airway clearance techniques had no significant effect on how the test was tolerated, the volume expectorated or the quality of the sample obtained (assessed by the presence of alveolar macrophages). The techniques did not significantly affect how often the test identified a suspected organism, nor the sensitivity or specificity of sputum induction. In conclusion, the study was unable to demonstrate any effect of airway clearance techniques on the sputum induction procedure. The results provide some justification for not including airway clearance techniques as part of the sputum induction procedure.

Multiparameter immune profiling of operational tolerance in liver transplantation.

PubMed

Martínez-Llordella, M; Puig-Pey, I; Orlando, G; Ramoni, M; Tisone, G; Rimola, A; Lerut, J; Latinne, D; Margarit, C; Bilbao, I; Brouard, S; Hernández-Fuentes, M; Soulillou, J-P; Sánchez-Fueyo, A

2007-02-01

Immunosuppressive drugs can be completely withdrawn in up to 20% of liver transplant recipients, commonly referred to as 'operationally' tolerant. Immune characterization of these patients, however, has not been performed in detail, and we lack tests capable of identifying tolerant patients among recipients receiving maintenance immunosuppression. In the current study we have analyzed a variety of biological traits in peripheral blood of operationally tolerant liver recipients in an attempt to define a multiparameter 'fingerprint' of tolerance. Thus, we have performed peripheral blood gene expression profiling and extensive blood cell immunophenotyping on 16 operationally tolerant liver recipients, 16 recipients requiring on-going immunosuppressive therapy, and 10 healthy individuals. Microarray profiling identified a gene expression signature that could discriminate tolerant recipients from immunosuppression-dependent patients with high accuracy. This signature included genes encoding for gammadelta T-cell and NK receptors, and for proteins involved in cell proliferation arrest. In addition, tolerant recipients exhibited significantly greater numbers of circulating potentially regulatory T-cell subsets (CD4+ CD25+ T-cells and Vdelta1+ T cells) than either non-tolerant patients or healthy individuals. Our data provide novel mechanistic insight on liver allograft operational tolerance, and constitute a first step in the search for a non-invasive diagnostic signature capable of predicting tolerance before undergoing drug weaning.

High-dose cytarabine as salvage therapy for relapsed or refractory acute myeloid leukemia--is more better or more of the same?

PubMed

Wolach, Ofir; Itchaki, Gilad; Bar-Natan, Michal; Yeshurun, Moshe; Ram, Ron; Herscovici, Corina; Shpilberg, Ofer; Douer, Dan; Tallman, Martin S; Raanani, Pia

2016-03-01

Cytarabine is the backbone of most chemotherapeutic regimens for acute myeloid leukemia (AML), yet the optimal dose for salvage therapy of refractory or relapsed AML (RR-AML) has not been established. Very high dose single-agent cytarabine at 36 g/m(2) (ARA-36) was previously shown to be effective and tolerable in RR-AML. In this retrospective analysis, we aim to describe the toxicity and efficacy of ARA-36 as salvage therapy for patients with AML who are primary refractory to intensive daunorubicin-containing induction or those relapsing after allogeneic stem cell transplant (alloSCT). Fifteen patients, median age 53 years, were included in the analysis. Six patients were treated for induction failure, one had resistant APL, and eight relapsed after alloSCT. Complete remission was achieved in 60% of patients. Surviving patients were followed for a median of 8.5 months. One-year overall survival was 54% (95% CI 30%-86%), and relapse rate from remission (n = 9) was 56%. Grade III/IV pulmonary, infectious, ocular and gastrointestinal toxicities occurred in 26%, 20%, 20% and 20% of patients respectively. Salvage therapy with ARA-36 regimen for RR-AML has considerable efficacy with manageable toxicity in patients with induction failure or post-transplant relapse. Overall survival in these high-risk patients still remains poor. Copyright © 2015 John Wiley & Sons, Ltd.

Multimodal charge-induction chromatography for antibody purification.

PubMed

Tong, Hong-Fei; Lin, Dong-Qiang; Chu, Wen-Ning; Zhang, Qi-Lei; Gao, Dong; Wang, Rong-Zhu; Yao, Shan-Jing

2016-01-15

Hydrophobic charge-induction chromatography (HCIC) has advantages of high capacity, salt-tolerance and convenient pH-controlled elution. However, the binding specificity might be improved with multimodal molecular interactions. New ligand W-ABI that combining tryptophan and 5-amino-benzimidazole was designed with the concept of mutimodal charge-induction chromatography (MCIC). The indole and benzimidazole groups of the ligand could provide orientated mutimodal binding to target IgG under neutral pH, while the imidazole groups could induce the electrostatic repulsion forces for efficient elution under acidic pH. W-ABI ligand was coupled successfully onto agarose gel, and IgG adsorption behaviors were investigated. High affinity to IgG was found with the saturated adsorption capacity of 70.4 mg/ml at pH 7, and the flow rate of mobile phase showed little impact on the dynamic binding capacity. In addition, efficient elution could be achieved at mild acidic pH with high recovery. Two separation cases (IgG separation from albumin containing feedstock and monoclonal antibody purification from cell culture supernatant) were verified with high purity and recovery. In general, MCIC with the specially-designed ligand is an expanding of HCIC with improved adsorption selectivity, which would be a potential alternative to Protein A-based capture for the cost-effective purification of antibodies. Copyright © 2015 Elsevier B.V. All rights reserved.

Prospective, open, multicentre Phase I/II trial to assess safety and efficacy of neoadjuvant radiochemotherapy with docetaxel and cisplatin for esophageal carcinoma.

PubMed

Ma, Hong-Bing; Di, Zheng-Li; Wen, Jiao; Ke, Yue; Sun, Xiaodong; Ren, Juan

2015-02-01

Esophageal squamous cell carcinoma is increasingly treated with trimodality therapy. The objective of this Phase I/II clinical study is to assess the efficacy and safety of neoadjuvant radiochemotherapy with docetaxel and cisplatin and radiotherapy in patients with esophagectomy for locally advanced squamous cell carcinoma of the esophagus with neoadjuvant chemoradiotherapy. Patients with esophageal squamous cell carcinoma received radiochemotherapy (50 Gy/25 fractions during Weeks 1-5) using a three-dimensional conformal radiation therapy or intensity-modulated radiation therapy technique together with weekly docetaxel (20 mg/m(2) at dose levels 1 and 2, 25 mg/m(2) at dose level 3 on Weeks 1-5) and cisplatin (30 mg/m(2) at dose level 1, 40 mg/m(2) at dose levels 2 and 3 on Weeks 1-5) from January 2009 to December 2011. The dose-limiting toxicities and maximum tolerated dose were the primary endpoints and overall response rate and progression-free survival were the secondary endpoints. Over this timeframe, a total of 49 patients completed trimodality therapy. Thirteen patients were treated at dose level 1, 21 patients at dose level 2 and 15 patients at dose level 3.The maximum tolerated dose for docetaxel was 20 mg/m(2) and cisplatin 40 mg/m(2). The complete response or partial response was observed in 26.5% (13/49) of patients. Thirty-four patients (69.4%) were treated with neoadjuvant radiochemotherapy followed by surgical resection. The median progression-free survival and median overall survival for all patients (n = 49) were 8 and 17.2 months, respectively. The median overall survival was 27.5 months for patients treated at dose level 2. Neoadjuvant radiochemotherapy with docetaxel 20 mg/m(2) and cisplatin 40 mg/m(2) was effective and tolerable induction regimen in patients with esophageal tumors. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Effects of traditional Tibetan drug Liu Tea on proliferation and chemotherapeutic sensitivity of drug-resistant human gastric cancer cell BGC823/5-FU].

PubMed

Cheng, Yan; Hasiqi, Mei-Ge; Qin, Xiao-Zhen; Tang, Xiang-You; Chen, Jian-Nan; Wang, Hui-Yin; Gao, Ao

2016-02-01

To investigate the effects of Liu Tea extracts(LTE) on proliferation, apoptosis and drug sensitivity of drug-resistant gastric cancer cell BGC823/5-FU. MTT assay was used to analyze effect of LTE on cell growth and sensitivity chemotherapeutic drugs, and synergistic effect of the combination of LTE with 5-FU on BGC823/5-FU cells. Combination index (CI) was calculated by CompuSyn. Cell apoptosis was measured by flow cytometry (FCM). Protein expressions of P-gp, Bcl-2, Bax and Caspase-3 (17KD) were detected by Western blot at different concentrations of LTE in BGC823/5-FU cells (100, 200, 400 mg•L⁻¹). The results showed that LTE had an inhibitory effect on growth of BGC823/5-FU cell in a dose-time-dependent manner and significantly reduced IC₅₀ of 5-FU, CDDP, PTX and ADM to BGC823/5-FU cells(P<0.05), indicating it could reverse tolerance of drug resistant cells to chemotherapeutic drugs, with reversion multiples of 2.35, 1.68, 1.96, 0.52. The combination of LTE with 5-FU had positive synergistic effect on the BGC-823 cell line. FCM assay suggested that LTE could induce BGC823/5-FU apoptosis. The apoptosis rate was up to 46.2% when the cells were treated with 800 mg•L⁻¹ LTE after 24 h(P<0.01). According to the protein detection results, with the increase in concentration of LTE, the protein expression of Bcl-2 was gradually decreased(P<0.01), the expression of Bax and Caspase-3 were extremely increased(P<0.01), with statistical significance in difference(P<0.01) but no difference in the expression of P-gp between experiment group and control group. LTE can inhibit the growth of drug-resistant human gastric cancer cell BGC823/5-FU and reverse its chemotherapeutic tolerance to some extent. Inhibition of antiapoptotic proteins, activation of proapoptotic proteins and induction of apoptosis of resistant cells may be its main mechanisms. Copyright© by the Chinese Pharmaceutical Association.

Comparison of 2D and 3D neural induction methods for the generation of neural progenitor cells from human induced pluripotent stem cells.

PubMed

Chandrasekaran, Abinaya; Avci, Hasan X; Ochalek, Anna; Rösingh, Lone N; Molnár, Kinga; László, Lajos; Bellák, Tamás; Téglási, Annamária; Pesti, Krisztina; Mike, Arpad; Phanthong, Phetcharat; Bíró, Orsolya; Hall, Vanessa; Kitiyanant, Narisorn; Krause, Karl-Heinz; Kobolák, Julianna; Dinnyés, András

2017-12-01

Neural progenitor cells (NPCs) from human induced pluripotent stem cells (hiPSCs) are frequently induced using 3D culture methodologies however, it is unknown whether spheroid-based (3D) neural induction is actually superior to monolayer (2D) neural induction. Our aim was to compare the efficiency of 2D induction with 3D induction method in their ability to generate NPCs, and subsequently neurons and astrocytes. Neural differentiation was analysed at the protein level qualitatively by immunocytochemistry and quantitatively by flow cytometry for NPC (SOX1, PAX6, NESTIN), neuronal (MAP2, TUBB3), cortical layer (TBR1, CUX1) and glial markers (SOX9, GFAP, AQP4). Electron microscopy demonstrated that both methods resulted in morphologically similar neural rosettes. However, quantification of NPCs derived from 3D neural induction exhibited an increase in the number of PAX6/NESTIN double positive cells and the derived neurons exhibited longer neurites. In contrast, 2D neural induction resulted in more SOX1 positive cells. While 2D monolayer induction resulted in slightly less mature neurons, at an early stage of differentiation, the patch clamp analysis failed to reveal any significant differences between the electrophysiological properties between the two induction methods. In conclusion, 3D neural induction increases the yield of PAX6 + /NESTIN + cells and gives rise to neurons with longer neurites, which might be an advantage for the production of forebrain cortical neurons, highlighting the potential of 3D neural induction, independent of iPSCs' genetic background. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Acetylcholine-producing NK cells attenuate CNS inflammation via modulation of infiltrating monocytes/macrophages.

PubMed

Jiang, Wei; Li, Daojing; Han, Ranran; Zhang, Chao; Jin, Wei-Na; Wood, Kristofer; Liu, Qiang; Shi, Fu-Dong; Hao, Junwei

2017-07-25

The nonneural cholinergic system of immune cells is pivotal for the maintenance of immunological homeostasis. Here we demonstrate the expression of choline acetyltransferase (ChAT) and cholinergic enzymes in murine natural killer (NK) cells. The capacity for acetylcholine synthesis by NK cells increased markedly under inflammatory conditions such as experimental autoimmune encephalomyelitis (EAE), in which ChAT expression escalated along with the maturation of NK cells. ChAT + and ChAT - NK cells displayed distinctive features in terms of cytotoxicity and chemokine/cytokine production. Transfer of ChAT + NK cells into the cerebral ventricles of CX3CR1 -/- mice reduced brain and spinal cord damage after EAE induction, and decreased the numbers of CNS-infiltrating CCR2 + Ly6C hi monocytes. ChAT + NK cells killed CCR2 + Ly6C hi monocytes directly via the disruption of tolerance and inhibited the production of proinflammatory cytokines. Interestingly, ChAT + NK cells and CCR2 + Ly6C hi monocytes formed immune synapses; moreover, the impact of ChAT + NK cells was mediated by α7-nicotinic acetylcholine receptors. Finally, the NK cell cholinergic system up-regulated in response to autoimmune activation in multiple sclerosis, perhaps reflecting the severity of disease. Therefore, this study extends our understanding of the nonneural cholinergic system and the protective immune effect of acetylcholine-producing NK cells in autoimmune diseases.

B-Lymphocytes Expressing an Ig Specificity Recognizing the Pancreatic β-Cell Autoantigen Peripherin Are Potent Contributors to Type 1 Diabetes Development in NOD Mice

PubMed Central

Leeth, Caroline M.; Racine, Jeremy; Chapman, Harold D.; Arpa, Berta; Carrillo, Jorge; Carrascal, Jorge; Wang, Qiming; Ratiu, Jeremy; Egia-Mendikute, Leire; Rosell-Mases, Estela; Stratmann, Thomas

2016-01-01

Although the autoimmune destruction of pancreatic β-cells underlying type 1 diabetes (T1D) development is ultimately mediated by T cells in NOD mice and also likely in humans, B cells play an additional key pathogenic role. It appears that the expression of plasma membrane–bound Ig molecules that efficiently capture β-cell antigens allows autoreactive B cells that bypass normal tolerance induction processes to be the subset of antigen-presenting cells most efficiently activating diabetogenic T cells. NOD mice transgenically expressing Ig molecules recognizing antigens that are (insulin) or are not (hen egg lysozyme [HEL]) expressed by β-cells have proven useful in dissecting the developmental basis of diabetogenic B cells. However, these transgenic Ig specificities were originally selected for their ability to recognize insulin or HEL as foreign, rather than autoantigens. Thus, we generated and characterized NOD mice transgenically expressing an Ig molecule representative of a large proportion of naturally occurring islet-infiltrating B cells in NOD mice recognizing the neuronal antigen peripherin. Transgenic peripherin-autoreactive B cells infiltrate NOD pancreatic islets, acquire an activated proliferative phenotype, and potently support accelerated T1D development. These results support the concept of neuronal autoimmunity as a pathogenic feature of T1D, and targeting such responses could ultimately provide an effective disease intervention approach. PMID:26961115

Modulation Between High- and Low-Frequency Transcutaneous Electric Nerve Stimulation Delays the Development of Analgesic Tolerance in Arthritic Rats

PubMed Central

DeSantana, Josimari M.; Santana-Filho, Valter J.; Sluka, Kathleen A.

2009-01-01

Objective To investigate whether repeated administration of modulating frequency transcutaneous electric nerve stimulation (TENS) prevents development of analgesic tolerance. Design Knee joint inflammation (3% carrageenan and kaolin) was induced in rats. Either mixed or alternating frequency was administered daily (20min) for 2 weeks to the inflamed knee under light halothane anesthesia (1%–2%). Setting Laboratory. Animals Adult male Sprague-Dawley rats (N=36). Intervention Mixed- (4Hz and 100Hz) or alternating- (4Hz on 1 day; 100Hz on the next day) frequency TENS at sensory intensity and 100μs pulse duration. Main Outcome Measures Paw and joint withdrawal thresholds to mechanical stimuli were assessed before induction of inflammation, and before and after daily application of TENS. Results The reduced paw and joint withdrawal thresholds that occur 24 hours after the induction of inflammation were significantly reversed by the first administration of TENS when compared with sham treatment or to the condition before TENS treatment, which was observed through day 9. By the tenth day, repeated daily administration of either mixed- or alternating-frequency TENS did not reverse the decreased paw and joint withdrawal thresholds. Conclusions These data suggest that repeated administration of modulating frequency TENS leads to a development of opioid tolerance. However, this tolerance effect is delayed by approximately 5 days compared with administration of low- or high-frequency TENS independently. Clinically, we can infer that a treatment schedule of repeated daily TENS administration will result in a tolerance effect. Moreover, modulating low and high frequency TENS seems to produce a better analgesic effect and tolerance is slower to develop. PMID:18374009

Analysis of drought-tolerant sugar beet (Beta vulgaris L.) mutants induced with gamma radiation using SDS-PAGE and ISSR markers.

PubMed

Sen, Ayse; Alikamanoglu, Sema

2012-01-01

Drought is one of the major environmental stresses which greatly affect the plant growth and productivity. In the present study, various doses (0-75Gy) of gamma rays were applied to investigate the effect of radiation on shoot tip explants. It was observed that the regeneration rates and plant fresh weights decreased significantly with an increase in radiation dose. The optimal irradiation doses for mutation induction were determined at 15 and 20Gy. Afterwards, the induction of somatic mutation in sugar beet (Beta vulgaris L.) was investigated by irradiation of shoot tips with 15 and 20Gy gamma rays. Irradiated shoot tips were sub-cultured and M(1)V(1)-M(1)V(3) generations were obtained. Mutants tolerant to drought stress were selected on MS medium, supplemented with 10 and 20gl(-1) PEG6000. Of the M(1)V(3) plantlets, drought-tolerant mutants were selected. Leaf soluble proteins obtained from the control and drought-tolerant mutants were analyzed by SDS-PAGE. A total of 22 protein bands were determined and 2 of them were observed to be drought-tolerant mutants except the control. Polymorphism was also detected among the control and drought-tolerant mutants by DNA fingerprinting using ISSR markers. A total of 106 PCR fragments were amplified with 19 ISSR primers and 91 of them were polymorphic. The dendrograms were separated into two main clusters. First cluster included M8 mutant plant, which was applied 20Gy gamma radiation and regenerated on selective culture media containing 10gl(-1) PEG6000 concentration, and the second cluster was further divided into five sub-clusters. Copyright © 2012 Elsevier B.V. All rights reserved.

Photoperiodic regulation of the C-repeat binding factor (CBF) cold acclimation pathway and freezing tolerance in Arabidopsis thaliana.

PubMed

Lee, Chin-Mei; Thomashow, Michael F

2012-09-11

The CBF (C-repeat binding factor) pathway has a major role in plant cold acclimation, the process whereby certain plants increase in freezing tolerance in response to low nonfreezing temperatures. In Arabidopsis thaliana, the pathway is characterized by rapid cold induction of CBF1, CBF2, and CBF3, which encode transcriptional activators, followed by induction of CBF-targeted genes that impart freezing tolerance. At warm temperatures, CBF transcript levels are low, but oscillate due to circadian regulation with peak expression occurring at 8 h after dawn (zeitgeber time 8; ZT8). Here, we establish that the CBF pathway is also regulated by photoperiod at warm temperatures. At ZT8, CBF transcript levels in short-day (SD; 8-h photoperiod) plants were three- to fivefold higher than in long-day plants (LD; 16-h photoperiod). Moreover, the freezing tolerance of SD plants was greater than that of LD plants. Genetic analysis indicated that phytochrome B (PHYB) and two phytochrome-interacting factors, PIF4 and PIF7, act to down-regulate the CBF pathway and freezing tolerance under LD conditions. Down-regulation of the CBF pathway in LD plants correlated with higher PIF4 and PIF7 transcript levels and greater stability of the PIF4 and PIF7 proteins under LD conditions. Our results indicate that during the warm LD growing season, the CBF pathway is actively repressed by PHYB, PIF4, and PIF7, thus mitigating allocation of energy and nutrient resources toward unneeded frost protection. This repression is relieved by shortening day length resulting in up-regulation of the CBF pathway and increased freezing tolerance in preparation for coming cold temperatures.

Photoperiodic regulation of the C-repeat binding factor (CBF) cold acclimation pathway and freezing tolerance in Arabidopsis thaliana

PubMed Central

Lee, Chin-Mei; Thomashow, Michael F.

2012-01-01

The CBF (C-repeat binding factor) pathway has a major role in plant cold acclimation, the process whereby certain plants increase in freezing tolerance in response to low nonfreezing temperatures. In Arabidopsis thaliana, the pathway is characterized by rapid cold induction of CBF1, CBF2, and CBF3, which encode transcriptional activators, followed by induction of CBF-targeted genes that impart freezing tolerance. At warm temperatures, CBF transcript levels are low, but oscillate due to circadian regulation with peak expression occurring at 8 h after dawn (zeitgeber time 8; ZT8). Here, we establish that the CBF pathway is also regulated by photoperiod at warm temperatures. At ZT8, CBF transcript levels in short-day (SD; 8-h photoperiod) plants were three- to fivefold higher than in long-day plants (LD; 16-h photoperiod). Moreover, the freezing tolerance of SD plants was greater than that of LD plants. Genetic analysis indicated that phytochrome B (PHYB) and two phytochrome-interacting factors, PIF4 and PIF7, act to down-regulate the CBF pathway and freezing tolerance under LD conditions. Down-regulation of the CBF pathway in LD plants correlated with higher PIF4 and PIF7 transcript levels and greater stability of the PIF4 and PIF7 proteins under LD conditions. Our results indicate that during the warm LD growing season, the CBF pathway is actively repressed by PHYB, PIF4, and PIF7, thus mitigating allocation of energy and nutrient resources toward unneeded frost protection. This repression is relieved by shortening day length resulting in up-regulation of the CBF pathway and increased freezing tolerance in preparation for coming cold temperatures. PMID:22927419

Induction of tolerance and prolongation of islet allograft survival by syngeneic hematopoietic stem cell transplantation in mice.

PubMed

Yang, Shi-feng; Xue, Wu-jun; Lu, Wan-hong; Xie, Li-yi; Yin, Ai-ping; Zheng, Jin; Sun, Ji-ping; Li, Yang

2015-10-01

Syngeneic or autologous hematopoietic stem cells transplantation (HSCT) has been proposed to treat autoimmune diseases because of its immunosuppressive and immunomodulatory effects, which can also contribute to posttransplant antirejection therapy. In this study, we explored the tolerogenic effect of syngeneic HSCT on prolonging islet allograft survival. C57BL/6 mice received syngeneic HSCT plus preconditioning with sublethal irradiation. Then islets of BALB/c mice were transplanted into the renal subcapsular of C57BL/6 mice after chemically induced into diabetes. HSCT mice exhibited improved islet allograft survival and increased serum insulin compared to control mice. Islet allografts of HSCT mice displayed lower level lymphocyte infiltration and stronger insulin staining than control mice. T cells of HSCT mice proliferated poorly in response to allogeneic splenocytes compared to control mice. Mice appeared reversed interferon-γ (IFN-γ)/interleukin-4 (IL-4) ratio to a Th2 immune deviation after syngeneic HSCT. The percentage of CD8(+) T cells was lower, while percentage of CD4(+)CD25(+)Foxp3(+) T regulatory cells (Tregs) was higher in HSCT mice than control mice. HSCT mice showed higher percentage of CTLA-4(+) T cells and expression of CTLA-4 mRNA than control mice. Targeting of CTLA-4 by intraperitoneal injection of anti-CTLA-4 mAb abrogated the effect of syngeneic HSCT on prolonging islet allograft survival, inhibiting activity of T cells in response to alloantigen, promoting Th1 to Th2 immune deviation and up regulating CD4(+)CD25(+)Foxp3(+) Tregs. Syngeneic HSCT plus preconditioning of sublethal irradiation induces tolerance and improves islet allograft survival in fully mismatched mice model. Th1 to Th2 immune deviation, increased CD4(+)CD25(+)Foxp3(+) Tregs and up-regulation of CTLA-4 maybe contribute to the tolerogenic effect induced by syngeneic HSCT. Copyright © 2015 Elsevier B.V. All rights reserved.

Magmas functions as a ROS regulator and provides cytoprotection against oxidative stress-mediated damages

PubMed Central

Srivastava, S; Sinha, D; Saha, P P; Marthala, H; D'Silva, P

2014-01-01

Redox imbalance generates multiple cellular damages leading to oxidative stress-mediated pathological conditions such as neurodegenerative diseases and cancer progression. Therefore, maintenance of reactive oxygen species (ROS) homeostasis is most important that involves well-defined antioxidant machinery. In the present study, we have identified for the first time a component of mammalian protein translocation machinery Magmas to perform a critical ROS regulatory function. Magmas overexpression has been reported in highly metabolically active tissues and cancer cells that are prone to oxidative damage. We found that Magmas regulates cellular ROS levels by controlling its production as well as scavenging. Magmas promotes cellular tolerance toward oxidative stress by enhancing antioxidant enzyme activity, thus preventing induction of apoptosis and damage to cellular components. Magmas enhances the activity of electron transport chain (ETC) complexes, causing reduced ROS production. Our results suggest that J-like domain of Magmas is essential for maintenance of redox balance. The function of Magmas as a ROS sensor was found to be independent of its role in protein import. The unique ROS modulatory role of Magmas is highlighted by its ability to increase cell tolerance to oxidative stress even in yeast model organism. The cytoprotective capability of Magmas against oxidative damage makes it an important candidate for future investigation in therapeutics of oxidative stress-related diseases. PMID:25165880

Enhancing monellin production by Pichia pastoris at low cell induction concentration via effectively regulating methanol metabolism patterns and energy utilization efficiency

PubMed Central

Jia, Luqiang; Tu, Tingyong; Huai, Qiangqiang; Sun, Jiaowen; Chen, Shanshan; Li, Xin; Ding, Jian

2017-01-01

In heterologous protein productions by P. pastoris, methanol induction is generally initiated when cell concentration reaches very high density. The alternative strategy by initiating methanol induction at lower cells concentration was also reported to be effective in easing DO control, reducing toxic by-metabolites accumulation and increasing targeted proteins titers. However, the methanol/energy regulation mechanisms are seldom reported. We theoretically analyzed the methanol/energy metabolisms in protein expression process with the strategies of initiating induction at higher or lower cells concentrations, using monellin production as a prototype. When initiating induction at lower cells concentration and controlling induction temperature at 30°C, monellin concentration reached the highest levels of 2.62~2.71 g/L, which was 2.5~4.9 fold of those obtained with the strategy of initiating induction at higher cells concentration. With the desired induction strategy, 1) carbon metabolism ratio directing into the precursors synthesis route for monellin production reached the highest level of 65%, carbon metabolism ratios towards to precursors synthesis and ATP regeneration routes were regulated at relatively balanced levels; 2) monellin synthesis was completely cell growth associated, with the largest associated coefficient and higher specific growth rate; 3) theoretical NADH (energy) utilization efficiency η was the highest, and η stayed high levels (≥0.8) during most period (89%) within induction phase to supply sufficient energy in supporting monellin synthesis. PMID:28981536

Enhancing monellin production by Pichia pastoris at low cell induction concentration via effectively regulating methanol metabolism patterns and energy utilization efficiency.

PubMed

Jia, Luqiang; Tu, Tingyong; Huai, Qiangqiang; Sun, Jiaowen; Chen, Shanshan; Li, Xin; Shi, Zhongping; Ding, Jian

2017-01-01

In heterologous protein productions by P. pastoris, methanol induction is generally initiated when cell concentration reaches very high density. The alternative strategy by initiating methanol induction at lower cells concentration was also reported to be effective in easing DO control, reducing toxic by-metabolites accumulation and increasing targeted proteins titers. However, the methanol/energy regulation mechanisms are seldom reported. We theoretically analyzed the methanol/energy metabolisms in protein expression process with the strategies of initiating induction at higher or lower cells concentrations, using monellin production as a prototype. When initiating induction at lower cells concentration and controlling induction temperature at 30°C, monellin concentration reached the highest levels of 2.62~2.71 g/L, which was 2.5~4.9 fold of those obtained with the strategy of initiating induction at higher cells concentration. With the desired induction strategy, 1) carbon metabolism ratio directing into the precursors synthesis route for monellin production reached the highest level of 65%, carbon metabolism ratios towards to precursors synthesis and ATP regeneration routes were regulated at relatively balanced levels; 2) monellin synthesis was completely cell growth associated, with the largest associated coefficient and higher specific growth rate; 3) theoretical NADH (energy) utilization efficiency η was the highest, and η stayed high levels (≥0.8) during most period (89%) within induction phase to supply sufficient energy in supporting monellin synthesis.

Systemic immunological tolerance to ocular antigens is mediated by TRAIL-expressing CD8+ T cells.

PubMed

Griffith, Thomas S; Brincks, Erik L; Gurung, Prajwal; Kucaba, Tamara A; Ferguson, Thomas A

2011-01-15

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required Fas ligand-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8(+) regulatory T cells. This study examined the mechanism by which these CD8(+) regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4(+) T cells and led to increased TRAIL expression by splenic CD8(+) T cells. Unlike wild-type mice, Trail(-/-) or Dr5(-/-) mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8(+) T cells from Trail(-/-) mice that were first injected via the AC with Ag were unable to transfer tolerance to naive recipient wild-type mice, but CD8(+) T cells from AC-injected wild-type or Dr5(-/-) mice could transfer tolerance. Importantly, the transferred wild-type (Trail(+/+)) CD8(+) T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail(-/-) CD8(+) T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that "helpless" CD8(+) regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye.

Systemic immunological tolerance to ocular antigens is mediated by TNF-related apoptosis-inducing ligand (TRAIL)-expressing CD8+ T cells*

PubMed Central

Griffith, Thomas S.; Brincks, Erik L.; Gurung, Prajwal; Kucaba, Tamara A.; Ferguson, Thomas A.

2010-01-01

Systemic immunological tolerance to Ag encountered in the eye restricts the formation of potentially damaging immune responses that would otherwise be initiated at other anatomical locations. We previously demonstrated that tolerance to Ag administered via the anterior chamber (AC) of the eye required FasL-mediated apoptotic death of inflammatory cells that enter the eye in response to the antigenic challenge. Moreover, the systemic tolerance induced after AC injection of Ag was mediated by CD8+ regulatory T cells. The present study examined the mechanism by which these CD8+ regulatory T cells mediate tolerance after AC injection of Ag. AC injection of Ag did not prime CD4+ T cells, and led to increased TRAIL expression by splenic CD8+ T cells. Unlike wildtype mice, Trail−/− or Dr5−/− mice did not develop tolerance to Ag injected into the eye, even though responding lymphocytes underwent apoptosis in the AC of the eyes of these mice. CD8+ T cells from Trail−/− mice that were first injected AC with Ag were unable to transfer tolerance to naïve recipient wildtype mice, but CD8+ T cells from AC-injected wildtype or Dr5−/− mice could transfer tolerance. Importantly, the transferred wildtype (Trail+/+) CD8+ T cells were also able to decrease the number of infiltrating inflammatory cells into the eye; however, Trail−/− CD8+ T cells were unable to limit the inflammatory cell ingress. Together, our data suggest that “helpless” CD8+ regulatory T cells generated after AC injection of Ag enforce systemic tolerance in a TRAIL-dependent manner to inhibit inflammation in the eye. PMID:21169546

Low-dose interleukin-2 as a modulator of Treg homeostasis after HSCT: current understanding and future perspectives.

PubMed

Matsuoka, Ken-Ichi

2018-02-01

CD4 + CD25 + Foxp3 + Treg is a functionally distinct subset of mature T cells with broad suppressive activity and has been shown to play an important role in the establishment of immune tolerance after HSCT. Altered cytokine environment in post-HSCT lymphopenia with a relative functional deficiency of IL-2 could hamper the reconstitution of Treg, leading to refractory GVHD. Based on the theory of low-dose IL-2 in which Treg can be selectively stimulated through the high-affinity IL-2 receptor, clinical studies have been conducted and demonstrated that low-dose IL-2 administration can restore Treg homeostasis and promote the expansion of this subset on the polymorphic processes of Treg reconstitution after HSCT. The new therapeutic indication of IL-2 for immune tolerance has launched in the field of HSCT and is spreading to the other fields including the treatment for autoimmune diseases. To further extend the indication of low-dose IL-2 to more patients with various immunological problems, the optimization of the timing and dosing of IL-2 intervention and the concomitant immune suppressive therapy according to each patient-based assessment are to be desired in the near future. Further prospective studies may facilitate the development of novel therapeutic algorithms for the effective and safe induction of immune tolerance after HSCT.

Characterization of two novel cold-inducible K3 dehydrin genes from alfalfa (Medicago sativa spp. sativa L.).

PubMed

Dubé, Marie-Pier; Castonguay, Yves; Cloutier, Jean; Michaud, Josée; Bertrand, Annick

2013-03-01

Dehydrin defines a complex family of intrinsically disordered proteins with potential adaptive value with regard to freeze-induced cell dehydration. Search within an expressed sequence tags library from cDNAs of cold-acclimated crowns of alfalfa (Medicago sativa spp. sativa L.) identified transcripts putatively encoding K(3)-type dehydrins. Analysis of full-length coding sequences unveiled two highly homologous sequence variants, K(3)-A and K(3)-B. An increase in the frequency of genotypes yielding positive genomic amplification of the K(3)-dehydrin variants in response to selection for superior tolerance to freezing and the induction of their expression at low temperature strongly support a link with cold adaptation. The presence of multiple allelic forms within single genotypes and independent segregation indicate that the two K(3) dehydrin variants are encoded by distinct genes located at unlinked loci. The co-inheritance of the K(3)-A dehydrin with a Y(2)K(4) dehydrin restriction fragment length polymorphism with a demonstrated impact on freezing tolerance suggests the presence of a genome domain where these functionally related genes are located. These results provide additional evidence that dehydrin play important roles with regard to tolerance to subfreezing temperatures. They also underscore the value of recurrent selection to help identify variants within a large multigene family in allopolyploid species like alfalfa.

Mechanisms of solvent resistance mediated by interplay of cellular factors in Pseudomonas putida.

PubMed

Ramos, Juan-Luis; Sol Cuenca, Maria; Molina-Santiago, Carlos; Segura, Ana; Duque, Estrella; Gómez-García, María R; Udaondo, Zulema; Roca, Amalia

2015-07-01

A number of microorganisms have the ability to thrive in the presence of a range of toxic solvents. Tolerance to these chemicals is a multifactorial process, meaning that bacterial cells use a set of physiological and gene expression changes to overcome the damage imparted by these chemicals. This review focuses mainly on issues related to tolerance to aromatic hydrocarbons and butanol in Pseudomonas, although other microorganisms are also discussed. Pseudomonas putida strains contain a circular chromosome of approximately 6 Mbp which encodes about 5300 genes. A combination of physiological and biochemical assays, a genome-wide collection of mutants and several omics approaches have provided useful information to help identify functions involved in solvent tolerance in P. putida. The solvent response involves fine-tuning of lipid fluidity to adjust membrane functions including impermeabilization, activation of a general stress-response system, increased energy generation and induction of specific efflux pumps that extrude solvents to the medium. These responses are modulated at the transcriptional level by local and global regulators as well as by a number of sRNAs whose levels fluctuate with the presence of solvents in the environment. Taken as a whole these regulatory inputs orchestrate the complex network of metabolic responses observed after solvent addition. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced glucocorticoid-induced leucine zipper in dendritic cells induces allergen-specific regulatory CD4(+) T-cells in respiratory allergies.

PubMed

Karaki, S; Garcia, G; Tcherakian, C; Capel, F; Tran, T; Pallardy, M; Humbert, M; Emilie, D; Godot, V

2014-05-01

Respiratory allergies rely on a defect of IL-10-secreting regulatory CD4(+) T-cells (IL-10-Tregs ) leading to excessive Th2-biased immune responses to allergens. According to clinical data, the restoration of allergen-specific IL-10-Tregs is required to control respiratory allergies and cure patients. The discovery of mechanisms involved in the generation of IL-10-Tregs will thus help to provide effective treatments. We previously demonstrated that dendritic cells (DCs) expressing high levels of the glucocorticoid-induced leucine zipper protein (GILZ) generate antigen-specific IL-10-Tregs . We suspect a defective expression of GILZ in the DCs of respiratory allergic patients and speculate that increasing its expression might restore immune tolerance against allergens through the induction of IL-10-Tregs . We assessed GILZ expression in blood DCs of patients and healthy nonallergic donors by qPCR. We compared the ability of patients' DCs to induce allergen-specific IL-10-Tregs before and after an in vivo up-regulation of GILZ expression by steroid administration, steroids being inducers of GILZ. We report lower levels of GILZ in DCs of respiratory allergic patients that return to normal levels after steroid administration. We show that patients' DCs with increased levels of GILZ generate allergen-specific IL-10-Tregs again. We further confirm unequivocally that GILZ is required in patients' DCs to activate these IL-10-Tregs . This proof of concept study shows that the re-establishment of GILZ expression in patients' DCs to normal levels restores their capacity to activate allergen-specific IL-10-Tregs . We thus highlight the up-regulation of GILZ in DCs as a new interventional approach to restore the immune tolerance to allergens. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Banana NAC transcription factor MusaNAC042 is positively associated with drought and salinity tolerance.

PubMed

Tak, Himanshu; Negi, Sanjana; Ganapathi, T R

2017-03-01

Banana is an important fruit crop and its yield is hampered by multiple abiotic stress conditions encountered during its growth. The NAC (NAM, ATAF, and CUC) transcription factors are involved in plant response to biotic and abiotic stresses. In the present study, we studied the induction of banana NAC042 transcription factor in drought and high salinity conditions and its overexpression in transgenic banana to improve drought and salinity tolerance. MusaNAC042 expression was positively associated with stress conditions like salinity and drought and it encoded a nuclear localized protein. Transgenic lines of banana cultivar Rasthali overexpressing MusaNAC042 were generated by Agrobacterium-mediated transformation of banana embryogenic cells and T-DNA insertion was confirmed by PCR and Southern blot analysis. Our results using leaf disc assay indicated that transgenic banana lines were able to tolerate drought and high salinity stress better than the control plants and retained higher level of total chlorophyll and lower level of MDA content (malondialdehyde). Transgenic lines analyzed for salinity (250 mM NaCl) and drought (Soil gravimetric water content 0.15) tolerance showed higher proline content, better Fv/Fm ratio, and lower levels of MDA content than control suggesting that MusaNAC042 may be involved in responses to higher salinity and drought stresses in banana. Expression of several abiotic stress-related genes like those coding for CBF/DREB, LEA, and WRKY factors was altered in transgenic lines indicating that MusaNAC042 is an efficient modulator of abiotic stress response in banana.

Emerging therapy in arthritis: Modulation of markers of the inflammatory process.

PubMed

Mortarino, P A; Goy, D P; Abramson, D B; Cabello, J; Bumaguin, G E; Vitelli, E J; Toledo, J; Sarrio, L; Pezzotto, S M; Mardegan Issa, J P; Cointry, G R; Feldman, S

2016-02-01

The induction of tolerance has been proposed as a therapeutic strategy for arthritis aiming to decrease progression of the pathology, probably by promoting suppressor mechanisms of the autoimmune response. This work aimed to confirm whether the treatment with vitamin D3 could synergize oral tolerance induced by hydrolyzed collagen peptides, in our experimental model of antigen induced arthritis in New Zealand rabbits. Clinical observation of the phenomenon indicates that simultaneous treatment with hydrolyzed collagen peptides and vitamin D3 was beneficial when compared with no treatment, for arthritic animals, and for arthritic animals that received treatment with only hydrolyzed collagen peptides or vitamin D3. Treatment with hydrolyzed collagen peptides caused diminished proinflammatory cytokine levels, an effect synergized significantly by the simultaneous treatment with vitamin D3. The anatomical-pathological studies of the animals that received both treatments simultaneously showed synovial tissues without lymphocytic and plasma cell infiltrates, and without vascular proliferation. Some of the synovial tissue of the animals of these groups showed a slight decrease in Galectin-3 expression. We propose that simultaneous oral treatment with vitamin D3 and hydrolyzed collagen peptides could increase the immunoregulatory effect on the process of previously triggered arthritis. We used articular cartilage hydrolysate and not collagen II because peptides best expose antigenic determinants that could induce oral tolerance. Oral tolerance may be considered in the design of novel alternative therapies for autoimmune disease and we have herein presented novel evidence that the simultaneous treatment with vitamin D3 may synergize this beneficial effect. © 2016 Wiley Periodicals, Inc.

Effect of caffeine on the ultraviolet light induction of SV40 virus from transformed hamster cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zamansky, G.B.; Kleinman, L.F.; Little, J.B.

1976-01-01

The effect of caffeine on the uv light induction of SV40 virus from two transformed hamster cell lines heterogeneous for the induction of infectious virus was studied. The amount of virus induced was significantly increased in both cell lines when exposure to uv light was followed by treatment with caffeine. Caffeine in the absence of uv irradiation did not stimulate virus induction, nor did it stimulate SV40 replication in a lytic infection. There was an apparent difference in the concentrations of caffeine which maximally stimulated SV40 virus induction in the two cell lines. This effect could not be explained bymore » differences in cell survival after exposure to uv light and caffeine. Since caffeine is known to cause the accumulation of gaps formed in DNA during postreplication repair of uv-irradiated rodent cells, our results support the hypothesis that the formation of gaps or breaks in DNA is an important early step in virus induction.« less

A RhABF2/Ferritin module affects rose (Rosa hybrida) petal dehydration tolerance and senescence by modulating iron levels.

PubMed

Liu, Jitao; Fan, Youwei; Zou, Jing; Fang, Yiqun; Wang, Linghao; Wang, Meng; Jiang, Xinqiang; Liu, Yiqing; Gao, Junping; Zhang, Changqing

2017-12-01

Plants often develop the capacity to tolerate moderate and reversible environmental stresses, such as drought, and to re-establish normal development once the stress has been removed. An example of this phenomenon is provided by cut rose (Rosa hybrida) flowers, which experience typical reversible dehydration stresses during post-harvest handling after harvesting at the bud stages. The molecular mechanisms involved in rose flower dehydration tolerance are not known, however. Here, we characterized a dehydration- and abscisic acid (ABA)-induced ferritin gene (RhFer1). Dehydration-induced free ferrous iron (Fe 2+ ) is preferentially sequestered by RhFer1 and not transported outside of the petal cells, to restrict oxidative stresses during dehydration. Free Fe 2+ accumulation resulted in more serious oxidative stresses and the induction of genes encoding antioxidant enzyme in RhFer1-silenced petals, and poorer dehydration tolerance was observed compared with tobacco rattle virus (TRV) controls. We also determined that RhABF2, an AREB/ABF transcription factor involved in the ABA signaling pathway, can activate RhFer1 expression by directly binding to its promoter. The silencing of RhABF2 decreased dehydration tolerance and disrupted Fe homeostasis in rose petals during dehydration, as did the silencing of RhFer1. Although both RhFer1 and Fe transporter genes are induced during flower natural senescence in plants, the silencing of RhABF2 or RhFer1 accelerates the petal senescence processes. These results suggest that the regulatory module RhABF2/RhFer1 contributes to the maintenance of Fe levels and enhances dehydration tolerance through the action of RhFer1 locally sequestering free Fe 2+ under dehydration conditions, and plays synergistic roles with transporter genes during flower senescence. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

PRODUCTION OF IMMUNOLOGICAL TOLERANCE IN MICE AFTER REPEATED INJECTIONS OF DISRUPTED SPLEEN CELLS

PubMed Central

Martinez, C.; Smith, J. M.; Blaese, M.; Good, R. A.

1963-01-01

1. Tolerance of male skin isografts has been regularly produced in female mice of the C57B1 strain sublines 1, 4, and 6 during adult life by repeated injection of completely disrupted spleen cells derived from male donors. The tolerant state is long-lasting since such grafts have remained in place more than 9 months. 2. Prolonged survival of homotransplants of skin has regularly been produced in DBA/2 mice during adult life by repeated injections of completely disrupted spleen cells from Balb/C donors. When injections of disrupted spleen cell material are continued over a sufficiently long period, permanent acceptance of the skin homografts may be obtained between these strains. 3. Immunological tolerance across even the strong H-2 histocompatibility barrier was obtained in the neonatal period and during adult life by repeated injection of disrupted spleen cell preparations. The tolerant state has been revealed by both mammary adenocarcinoma and skin homografting across this strong histocompatibility barrier. 4. In contradistinction to the tolerant state produced by injection of intact spleen cells in neonatal animals or during adult life or that produced by parabiotic union, the tolerance produced by repeated injection of disrupted spleen cell preparations cannot be transferred to syngenic neonatal mice with spleen cells of the tolerant animal. 5. The implications of these findings in transplantation biology and in consideration of the basic nature of tolerance are discussed. PMID:14087619

Transcription Factor-Mediated Control of Anthocyanin Biosynthesis in Vegetative Tissues1[OPEN

PubMed Central

Outchkourov, Nikolay S.; Schrama, Xandra; Blilou, Ikram; Jongedijk, Esmer; Simon, Carmen Diez; Bosch, Dirk; Hall, Robert D.

2018-01-01

Plants accumulate secondary metabolites to adapt to environmental conditions. These compounds, here exemplified by the purple-colored anthocyanins, are accumulated upon high temperatures, UV-light, drought, and nutrient deficiencies, and may contribute to tolerance to these stresses. Producing compounds is often part of a more broad response of the plant to changes in the environment. Here we investigate how a transcription-factor-mediated program for controlling anthocyanin biosynthesis also has effects on formation of specialized cell structures and changes in the plant root architecture. A systems biology approach was developed in tomato (Solanum lycopersicum) for coordinated induction of biosynthesis of anthocyanins, in a tissue- and development-independent manner. A transcription factor couple from Antirrhinum that is known to control anthocyanin biosynthesis was introduced in tomato under control of a dexamethasone-inducible promoter. By application of dexamethasone, anthocyanin formation was induced within 24 h in vegetative tissues and in undifferentiated cells. Profiles of metabolites and gene expression were analyzed in several tomato tissues. Changes in concentration of anthocyanins and other phenolic compounds were observed in all tested tissues, accompanied by induction of the biosynthetic pathways leading from Glc to anthocyanins. A number of pathways that are not known to be involved in anthocyanin biosynthesis were observed to be regulated. Anthocyanin-producing plants displayed profound physiological and architectural changes, depending on the tissue, including root branching, root epithelial cell morphology, seed germination, and leaf conductance. The inducible anthocyanin-production system reveals a range of phenomena that accompanies anthocyanin biosynthesis in tomato, including adaptions of the plants architecture and physiology. PMID:29192027

Attenuated microglial activation mediates tolerance to the neurotoxic effects of methamphetamine.

PubMed

Thomas, David M; Kuhn, Donald M

2005-02-01

Methamphetamine causes persistent damage to dopamine nerve endings of the striatum. Repeated, intermittent treatment of mice with low doses of methamphetamine leads to the development of tolerance to its neurotoxic effects. The mechanisms underlying tolerance are not understood but clearly involve more than alterations in drug bioavailability or reductions in the hyperthermia caused by methamphetamine. Microglia have been implicated recently as mediators of methamphetamine-induced neurotoxicity. The purpose of the present studies was to determine if a tolerance regimen of methamphetamine would attenuate the microglial response to a neurotoxic challenge. Mice treated with a low-dose methamphetamine tolerance regimen showed minor reductions in striatal dopamine content and low levels of microglial activation. When the tolerance regimen preceded a neurotoxic challenge of methamphetamine, the depletion of dopamine normally seen was significantly attenuated. The microglial activation that occurs after a toxic methamphetamine challenge was blunted likewise. Despite the induction of tolerance against drug-induced toxicity and microglial activation, a neurotoxic challenge with methamphetamine still caused hyperthermia. These results suggest that tolerance to methamphetamine neurotoxicity is associated with attenuated microglial activation and they further dissociate its neurotoxicity from drug-induced hyperthermia.