Search results for "Immunity"

Humoral Mechanisms in T cell Vaccination: Induction and Functional Characterization of Anti-lymphocytic Autoantibodies

1997

T cell vaccination, the application of syngeneic attenuated T cells, has been shown to prevent effectively and treat experimental autoimmune diseases, but its mechanisms of action are poorly understood. Here we present data on the induction of a humoral anti-T cell response by T cell vaccination, capable of strongly inhibiting T cell proliferation and of ameliorating experimental autoimmune disease. T cell vaccination in the Lewis rat induced autoantibodies reactive with several syngeneic T cell proteins. These autoantibodies were not detectable in normal Lewis sera as assessed by immunoblotting and flow cytometry with intact syngeneic T cells. The autoantibody reactivity was not restricted…

Interferon-α Abrogates Tolerance Induction by Human Tolerogenic Dendritic Cells

2011

Background Administration of interferon-α (IFN-α) represents an approved adjuvant therapy as reported for malignancies like melanoma and several viral infections. In malignant diseases, tolerance processes are critically involved in tumor progression. In this study, the effect of IFN-α on tolerance induction by human tolerogenic dendritic cells (DC) was analyzed. We focussed on tolerogenic IL-10-modulated DC (IL-10 DC) that are known to induce anergic regulatory T cells (iTregs). Methodology/Principal Findings IFN-α promoted an enhanced maturation of IL-10 DC as demonstrated by upregulation of the differentiation marker CD83 as well as costimulatory molecules. IFN-α treatment resulted in an…

Expression profiling of autoimmune regulator AIRE mRNA in a comprehensive set of human normal and neoplastic tissues.

2006

Defects in the autoimmune regulator (AIRE) gene cause the monogenic autoimmune disease autoimmune polyendocrinopathy syndrome type 1 (APS-1), which is characterized by a loss of self-tolerance to multiple organs. In concordance with its role in immune tolerance, AIRE is strongly expressed in medullary thymic epithelial cells (mTECs). Data on mechanisms controlling AIRE activation and the expression of this gene in other tissues are fragmentary and controversial. We report here AIRE mRNA expression profiling of a large set of normal human tissues and cells, tumor specimen and methylation deficient cell lines. On this broad data basis we found that AIRE mRNA expression is confined to mTECs in…

PO-CALC: A novel tool to correct common inconsistencies in the measurement of phenoloxidase activity

2015

Abstract A broad range of physiological and evolutionarily studies requires standard and robust methods to assess the strength and activity of an individual’s immune defense. In insects, this goal is generally reached by spectrophotometrically measuring (pro-) phenoloxidase activity, an enzymatic and non-specific process activated after wounding and parasite infections. However, the literature surprisingly lacks a standard method to calculate these values from spectrophotometer data and thus to be able to compare results across studies. In this study, we demonstrated that nine methods commonly used to extract phenoloxidase activities (1) provide inconsistent results when tested on the same …

Immunodefense in Tunicates: Cells and Molecules

2001

There are several reasons for analyzing tunicate immune systems. First, they can be established as primitive models for understanding fundamental immunological mechanisms by analyzing their individual cells and molecular products either in vivo or in vitro. Discovered mechanisms could provide alternatives to traditional (vertebrate) mammalian (mouse, rat) and emerging models (fish, amphibian reptile) in answering basic questions concerning immunity and disease in protochordates, the ancestors of vertebrates. Second in vitro, biochemical, immunochemical, and serological analyses coupled with molecular approaches are useful as we search for common molecules (e.g. markers of lymphocyte-like ce…

Resistance of Cancer Stem Cells to Cell-Mediated Immune Responses

2015

In the past decades, the hierarchical organization of tumors, governed by Cancer Stem Cells (CSCs), have been reported with regard to several tumor types. Advances in sequencing technologies have demonstrated that diverse genetic CSCs subclones, derived from the branching evolution, compete with each other within the tumor mass, thereby contributing to the functional heterogeneity. It is becoming increasingly clear that epigenetic modifications and microenvironmental influences are important determinants of tumor fitness resulting in disease progression, recurrence and reduced patient survival. Therefore, more effective therapies will require gaining insights into the role of genetic and no…

The T-cell response in patients with cancer

2002

Publisher Summary The chapter examines several methods to measure human T-cell responses, including ELISPOT analysis, intracellular cytokine staining of immune cells after antigenic stimulation, limiting dilution analysis, conventional cloning, and molecular definition of the T-cell response either in the peripheral circulation or in situ in patients with cancer The chapter presents the cellular immune response in patients with cancer. The chapter explores the recent studies that suggest humoral immunity and T-cell-mediated immunity are closely linked. In addition, most of the data concerning antitumor immune responses have been generated using MHC class I tetramer reagents. The ultimate go…

UVB light attenuates the systemic immune response in CNS autoimmunity

2014

Food-mediated modulation of immunity in a phytophagous insect: An effect of nutrition rather than parasitic contamination.

2015

7 pages; International audience; Inherent to the cost of immunity, the immune system itself can exhibit tradeoffs between its arms. Phytophagous insects face a wide range of microbial and eukaryotic parasites, each activating different immune pathways that could compromise the activity of the others. Feeding larvae are primarily exposed to microbes, which growth is controlled by antibiotic secondary metabolites produced by the host plant. The resulting variation in abundance of microbes on plants is expected to differentially stimulate the insect antimicrobial immune defenses. Under the above tradeoff hypothesis, stimulation of the insect antimicrobial defenses is expected to compromise imm…

Dendritic cells: sentinels of immunity and tolerance.

2005

The induction of effective antigen-specific T-cell immunity to pathogens without the initiation of autoimmunity has evolved as a sophisticated and highly balanced immunoregulatory mechanism. This mechanism assures the generation of antigen-specific effector cells as well as the induction and maintenance of antigen-specific tolerance to self-structures of the body. As professional antigen-presenting cells of the immune system, dendritic cells (DC) are ideally positioned throughout the entire body and equipped with a unique capability to transport antigens from the periphery to lymphoid tissues. There is growing evidence that DC, besides their well-known immunostimulatory properties, also ind…