Search results for " Helper-Inducer"
showing 10 items of 81 documents
Specific Regulation of T Helper Cell 1–mediated Murine Colitis by CEACAM1
2004
Carcinoembryonic antigen-related cellular adhesion molecule 1 (CEACAM1) is a cell surface molecule that has been proposed to negatively regulate T cell function. We have shown that CEACAM1 is associated with specific regulation of T helper cell (Th)1 pathways, T-bet–mediated Th1 cytokine signaling, and Th1-mediated immunopathology in vivo. Mice treated with anti–mouse CEACAM1-specific monoclonal antibody (mAb) CC1 during the effector phase exhibited a reduced severity of trinitrobenzene sulfonic acid colitis in association with decreased interferon (IFN)-γ production. Although oxazolone colitis has been reported as Th2 mediated, mice treated with the CC1 mAb or a CEACAM1-Fc chimeric protein…
Mast cells counteract regulatory T-cell suppression through interleukin-6 and OX40/OX40L axis toward Th17-cell differentiation
2009
Abstract The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell–derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17–producing T cel…
Generation of T Follicular Helper Cells Is Mediated by Interleukin-21 but Independent of T Helper 1, 2, or 17 Cell Lineages
2008
After activation, CD4(+) helper T (Th) cells differentiate into distinct effector subsets. Although chemokine (C-X-C motif) receptor 5-expressing T follicular helper (Tfh) cells are important in humoral immunity, their developmental regulation is unclear. Here we show that Tfh cells had a distinct gene expression profile and developed in vivo independently of the Th1 or Th2 cell lineages. Tfh cell generation was regulated by ICOS ligand (ICOSL) expressed on B cells and was dependent on interleukin-21 (IL-21), IL-6, and signal transducer and activator of transcription 3 (STAT3). However, unlike Th17 cells, differentiation of Tfh cells did not require transforming growth factor beta (TGF-beta…
Induction of tolerogenic lung CD4+ T cells by local treatment with a pSTAT-3 and pSTAT-5 inhibitor ameliorated experimental allergic asthma.
2010
Signal transducer and activator of transcription (STAT)-3 inhibitors play an important role in regulating immune responses. Galiellalactone (GL) is a fungal secondary metabolite known to interfere with the binding of phosphorylated signal transducer and activator of transcription (pSTAT)-3 as well of pSTAT-6 dimers to their target DNA in vitro. Intra nasal delivery of 50 μg GL into the lung of naive Balb/c mice induced FoxP3 expression locally and IL-10 production and IL-12p40 in RNA expression in the airways in vivo. In a murine model of allergic asthma, GL significantly suppressed the cardinal features of asthma, such as airway hyperresponsiveness, eosinophilia and mucus production, after…
Altered intracellular sorting signals do not influence the efficacy of genetic melanoma vaccines incorporating helper determinants in mice.
2004
Background A genetic melanoma vaccine consisting of cDNA encoding the model self-antigen tyrosinase-related protein 2 (TRP2) fused in-frame to the immunogenic enhanced green fluorescent protein (EGFP) was able to break immune tolerance and stimulate CD8+ T cells in vivo. In the present study we investigated whether alteration of the intracellular antigen localization as a result of the linkage with immune-enhancing helper proteins affects the resulting immune response. Methods Expression plasmids and recombinant adenoviruses were constructed encoding various fusion proteins with different intracellular sorting signals which direct the antigen to the cytosol, the endoplasmic reticulum or the…
Water-Soluble Polymers Coupled with Glycopeptide Antigens and T-Cell Epitopes as Potential Antitumor Vaccines
2013
Highly decorated: Tumor-associated MUC1 glycopeptide and tetanus toxoid T-cell epitope P2 can be attached to water-soluble poly(N-(2-hydroxypropyl)methacrylamide) carriers by orthogonal ligation techniques. Fully synthetic vaccine A with additional nanostructure-promoting domains induced antibodies that exhibit high affinity to tumor cells.
T-cell hyperreactivity of NZB mice against H-2 identical cells
1983
NZB mice serve as a model for human systemic lupus erythematodes. T-cell abnormalities in this strain have previously been described. In this paper the cytotoxic T lymphocyte precursor (CTL-p) frequencies of NZB mice against H-2 allogeneic and H-2 syngeneic cells are investigated and compared with those of the normal strain BALB/c. The CTL-p frequency in NZB lymphocytes against H-2 allogeneic cells equals that in normal mouse strains (i.e. 1/7500). The NZB anti BALB/c response is in the same order of magnitude. No corresponding BALB/c anti NZB response was elicited. The results suggest abnormally high sensitivity of NZB CTL-p to helper signals.
Infectious Tolerance
2002
Regulatory CD4(+)CD25(+) T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact-mediated suppression of conventional CD4(+) T cells by human CD25(+) Treg cells is fixation resistant, independent from membrane-bound TGF-beta but requires activation and protein synthesis of CD25(+) Treg cells. Coactivation of CD25(+) Treg cells with Treg cell-depleted CD4(+) T cells results in anergized CD4(+) T cells that in turn inhibit the activation of conventional, freshly isolated CD4(+) T helper (Th) cells. This infectious suppressive activity, transferred from CD25(+) Treg cells via cell contact, is cell contact-independent and partially medi…
Development, Differentiation, and Diversity of Innate Lymphoid Cells
2014
Recent years have witnessed the discovery of an unprecedented complexity in innate lymphocyte lineages, now collectively referred to as innate lymphoid cells (ILCs). ILCs are preferentially located at barrier surfaces and are important for protection against pathogens and for the maintenance of organ homeostasis. Inappropriate activation of ILCs has been linked to the pathogenesis of inflammatory and autoimmune disorders. Recent evidence suggests that ILCs can be grouped into two separate lineages, cytotoxic ILCs represented by conventional natural killer (cNK) cells and cytokine-producing helper-like ILCs (i.e., ILC1s, ILC2s, ILC3s). We will focus here on current work in humans and mice th…
Modification of the immune response against hepatitis B virus by the human immunodeficiency virus.
1989
Hepatitis B virus and the human immunodeficiency virus are similarly transmitted. Individuals with preexisting HIV infection have a higher chance to become HBsAg carriers than do anti-HIV negative persons. Cytotoxic T cells with specificity for HBcAg, that are under the control of HBcAg-specific helper T cells, are responsible for liver injury. There is good evidence that HIV infection lowers inflammatory activity, is associated with milder liver histology, high levels of viral replication and low seroconversion rates. In addition interferon alpha therapy is less effective in anti-HIV positive subjects. The immune response against HBsAg is helper T-cell dependent and vaccination against hep…