Search results for "interleukin"
showing 10 items of 1856 documents
Cyclic adenosine monophosphate is a key component of regulatory T cell–mediated suppression
2007
Naturally occurring regulatory T cells (T reg cells) are a thymus-derived subset of T cells, which are crucial for the maintenance of peripheral tolerance by controlling potentially autoreactive T cells. However, the underlying molecular mechanisms of this strictly cell contact–dependent process are still elusive. Here we show that naturally occurring T reg cells harbor high levels of cyclic adenosine monophosphate (cAMP). This second messenger is known to be a potent inhibitor of proliferation and interleukin 2 synthesis in T cells. Upon coactivation with naturally occurring T reg cells the cAMP content of responder T cells is also strongly increased. Furthermore, we demonstrate that natur…
The addition of interleukin-2 to cyclophosphamide therapy can facilitate tumor growth of B16 melanoma.
1995
The role of interleukin-2 (IL-2) on tumor growth of B16F10 melanoma cells was assessed in two sets of mice with different immune status: normal (immunocompetent) mice and immunodeficient mice. The two sets of animals were treated with cyclophosphamide (CY) or IL-2 alone or with a combined therapy of CY+IL-2. On days 6 and 10 after tumor cell injection, we evaluated the incidence of hepatic B16 melanoma metastases and the percentage of hepatic volume occupied by metastatic tissue. We observed that the CY alone (300 mg/kg, days 3 and 8 post-tumoral inoculation) significantly reduced tumor growth in all treated mice; however, CY proved more effective in normal recipients than in immunodeficien…
Mast cells promote Th1 and Th17 responses by modulating dendritic cell maturation and function
2011
Mast cells (MCs) play an important role in the regulation of protective adaptive immune responses against pathogens. However, it is still unclear whether MCs promote such host defense responses via direct effects on T cells or rather by modifying the functions of antigen-presenting cells. To identify the underlying mechanisms of the immunoregulatory capacity of MCs, we investigated the impact of MCs on dendritic cell (DC) maturation and function. We found that murine peritoneal MCs underwent direct crosstalk with immature DCs that induced DC maturation as evidenced by enhanced expression of costimulatory molecules. Furthermore, the MC/DC interaction resulted in the release of the T-cell mod…
Prevention and reversal of superantigen-induced anergy by contact allergen exposure
1995
The superantigen Staphylococcal enterotoxin B (SEB) and the contact allergen 2,4-dinitrofluorbenzene (DNFB) both react with V beta 8+ T-cells delivering distinct signals. Pre-treatment with DNFB painted onto the same skin site where SEB was to be injected, prevented the induction of anergy in V beta + T-cells that was otherwise induced after SEB had been injected intradermally over a period of 2 weeks. Application of the irritant sodium dodecyl sulfate (SDS) instead of DNFB did not exert this effect. Application of DNFB at a site distant from the site where SEB was injected resulted in a much weaker inhibitory influence on the induction of anergy by SEB. Established anergy of V beta 8+ T-ce…
Clostridium difficile toxins A and B inhibit human immune response in vitro
1988
Two Clostridium difficile toxins isolated from strain VPI 10463 were tested for their effect on different human T-cell proliferation systems. In mitogen- and antigen-driven T-cell proliferation systems, toxins inhibited the proliferative response in a dose-dependent fashion. In interleukin-2-driven culture systems, no effect of toxins could be found on preactivated T cells. We suspected that monocytes were the influenced cells, since in antigen- and mitogen-driven systems monocytes were necessary for the proliferative response, whereas the interleukin-2-driven system was independent of monocytes. To prove this concept, purified monocytes were treated with toxins. The treatment was found to …
Superior antitumor in vitro responses of allogeneic matched sibling compared with autologous patient CD8+ T cells.
2006
AbstractAllogeneic cell therapy as a means to break immunotolerance to solid tumors is increasingly used for cancer treatment. To investigate cellular alloimmune responses in a human tumor model, primary cultures were established from renal cell carcinoma (RCC) tissues of 56 patients. In three patients with stable RCC line and human leukocyte antigen (HLA)-identical sibling donor available, allogeneic and autologous RCC reactivities were compared using mixed lymphocyte/tumor cell cultures (MLTC). Responding lymphocytes were exclusively CD8+ T cells, whereas CD4+ T cells or natural killer cells were never observed. Sibling MLTC populations showed higher proliferative and cytolytic antitumor …
T cell factor (interleukin 2) allows in vivo induction of T helper cells against heterologous erythrocytes in athymic (nu/nu) mice.
1980
Mice carrying the nude mutation (nu/nu) lack a functioning thymus and do not contain detectable levels of immunocompetent T cells. We now report that nu/nu mice do have lymphocytes which can be activated in vivo by heterologous erythrocytes and a Lyt-1 T cell-derived factor (interleukin 2) to generate T helper cells. Thus, a lymphokine is described which is able to restore in vivo T helper cell immunocompetence of nu/nu mice. The data may suggest that nu/nu mice contain a low number of T lymphocytes influenced by the cystic remnant of the nu/nu thymus anlage. Alternatively, the data imply that interleukin 2 circumvents the requirement of a thymus during ontogeny of T lymphocytes.
Data mining-based statistical analysis of biological data uncovers hidden significance: clustering Hashimoto’s thyroiditis patients based on the resp…
2014
The pathogenesis of Hashimoto's thyroiditis includes autoimmunity involving thyroid antigens, autoantibodies, and possibly cytokines. It is unclear what role plays Hsp60, but our recent data indicate that it may contribute to pathogenesis as an autoantigen. Its role in the induction of cytokine production, pro- or anti-inflammatory, was not elucidated, except that we found that peripheral blood mononucleated cells (PBMC) from patients or from healthy controls did not respond with cytokine production upon stimulation by Hsp60 in vitro with patterns that would differentiate patients from controls with statistical significance. This "negative” outcome appeared when the data were pooled and ana…
A novel galactose- and arabinose-specific lectin from the sponge Pellina semitubulosa: isolation, characterization and immunobiological properties.
1992
A new lectin from the sponge Pellina semitubulosa is derived which was extracted and purified to homogeneity. The purified lectin is probably a hexamer of polypeptide chains (each M(r) 34,000) which are covalently linked via disulfide linkages; the isoelectric point is 6.1. The lectin displays the following specificities: D-galactose (50% inhibition of hemagglutination at 0.2 mM) = L-arabinose (0.2 mM) greater than D-fucose (1.5 mM) greater than D-glucose (3.0 mM). It precipitates human erythrocytes (A1, A2, A1B, B, and O) with a titer between 2(8) and 2(11) and erythrocytes from sheep and rabbits with a titer between 2(5) and 2(10). The Pellina lectin displays a strong mitogenic effect on …
The significance of serum soluble IL-2 receptor as a marker for active visceral leishmaniasis in Sicilian patients
1992
SUMMARY Sera from nine Sicilian patients with confirmed visceral leishmaniasis (Leishmania donovani infantum; VL), at the moment of the diagnosis, during the course of the disease and after clinical recovery, were analysed for the concentration of soluble IL-2 receptor (sIL-2R). The results show that sIL-2R is a marker of disease activity, since it is in high concentration at the beginning of infection and returns to the normal range following successful chemotherapy. At the same time of serum analysis for sIL-2R, peripheral blood mononuclear cells (PBMC) of VL patients were stimulated with phytohaemagglutinin (PHA) or antigen and supernatant tested for IL-2 and interferon-gamma (IFN-γ) pro…