Search results for "interleukin"
showing 10 items of 1856 documents
Interleukin-7
2003
This chapter discusses interleukin (IL)-7, which is an important lymphopoietin that plays a critical role in both B- and T-cell development. IL-7 promotes expansion of T lymphocytes exhibiting antigen-specific reactivity. IL-7 may be implemented to promote strong and effective immune responses against tumor cells, or directed against microbial or viral infections. It may also be useful in reconstituting an effective, and functional immune system after bone marrow transplantation, or helping to design novel strategies for immune reconstitution in patients with cancer or with HIV infection. IL-7 serves as the major growth and differentiation factor for both thymic and extrathymic development …
Suppressor activity of anergic T cells induced by IL-10-treated human dendritic cells: association with IL-2- and CTLA-4-dependent G1 arrest of the c…
2003
We have previously shown that human IL-10-treated dendritic cells (DC) induce an antigen-specific anergy in CD4+ T lymphocytes. These anergic T cells are characterized by an inhibited proliferation, a reduced production of IL-2, and additionally display antigen-specific suppressor activity. In this study we investigated the mechanisms underlying the anergic state and regulatory function of these T cells. We did not observe enhanced rates of programmed cell death of anergic CD4+ suppressor T cells compared to T cells stimulated with mature DC. Cell cycle analysis by DNA staining and Western blot experiments revealed an arrest of anergic CD4+ T suppressor cells in the G1 phase. High levels of…
Identification and Functional Characterization of Human Cd4+Cd25+ T Cells with Regulatory Properties Isolated from Peripheral Blood
2001
A subpopulation of peripheral human CD4(+)CD25(+) T cells that expresses CD45RO, histocompatibility leukocyte antigen DR, and intracellular cytotoxic T lymphocyte-associated antigen (CTLA) 4 does not expand after stimulation and markedly suppresses the expansion of conventional T cells in a contact-dependent manner. After activation, CD4(+)CD25(+) T cells express CTLA-4 on the surface detectable for several weeks. These cells show a G1/G0 cell cycle arrest and no production of interleukin (IL)-2, IL-4, or interferon (IFN)-gamma on either protein or mRNA levels. The anergic state of CD4(+)CD25(+) T cells is not reversible by the addition of anti-CD28, anti-CTLA-4, anti-transforming growth fa…
Human CD4+CD25+ T cells derived from the majority of atopic donors are able to suppress TH1 and TH2 cytokine production
2003
Abstract Background: Recently, it has been established that CD4 + CD25 + T cells with regulatory capacity are present in human peripheral blood, inhibiting allogeneic proliferation and cytokine production of preactivated CD4 + CD25 − respond-er T cells. Objective: The aim of this study was to analyze in an allergen-specific setting whether such regulatory CD4 + CD25 + T cells also exist and function normally in atopic individuals, especially concerning the inhibition of T H 2 cytokines. Methods: For this purpose, CD4 + CD25 − or CD4 + CD25 + T cells from donors allergic to grass or birch pollen (mainly with rhinitis) or from healthy nonatopic donors were stimulated in the presence of autolo…
Mast cells enhance proliferation of B lymphocytes and drive their differentiation toward IgA-secreting plasma cells.
2010
AbstractThe evidence of a tight spatial interaction between mast cells (MCs) and B lymphocytes in secondary lymphoid organs, along with the data regarding the abundance of MCs in several B-cell lymphoproliferative disorders prompted us to investigate whether MCs could affect the proliferation and differentiation of B cells. To this aim, we performed coculture assays using mouse splenic B cells and bone marrow–derived MCs. Both nonsensitized and activated MCs proved able to induce a significant inhibition of cell death and an increase in proliferation of naive B cells. Such proliferation was further enhanced in activated B cells. This effect relied on cell-cell contact and MC-derived interle…
Major histocompatibility complex regulation of interleukin-5 production in the mouse.
1993
Lymph node cells of CBA (H-2k), but not of BALB/c (H-2d) mice immunized epicutaneously with picryl chloryde secrete interleukin (IL)-5 when stimulated with the specific antigen in vitro. The low IL-5 production in BALB/c mice persists when either picryl chloride or the unrelated antigen oxazolone are used, when the amount of antigen in vitro is varied and when a secondary response is studied. The difference in IL-5 production maps to the major histocompatibility complex (MHC) in the congenic BALB/b, BALB/c and BALB/k mice. Furthermore, lymph node cells from (k × d) F1 mice produce IL-5 when stimulated by antigen presented on H-2k but not on H-2d antigen-presenting cells. Finally, the low IL…
Cytoskeletal stabilization of inhibitory interactions in immunologic synapses of mature human dendritic cells with natural killer cells
2011
Abstract Human mature dendritic cells (DCs) can efficiently stimulate natural killer (NK)–cell responses without being targeted by their cytotoxicity. To understand this important regulatory crosstalk, we characterized the development of the immunologic synapse between mature DCs and resting NK cells. Conjugates between these 2 innate leukocyte populations formed rapidly, persisted for prolonged time periods and matured with DC-derived f-actin polymerization at the synapse. Polarization of IL-12 and IL-12R to the synapse coincided with f-actin polymerization, while other activating and inhibitory molecules were enriched at the interface between DCs and NK cells earlier. Functional assays re…
Humoral immune response in IL-12 and IFN-gamma deficient mice after infection with Cryptosporidium parvum.
2008
Infection with Cryptosporidium spp. causes diarrhoeal disease and has become an important medical and veterinary problem especially in the immunocompromised host. The importance of the adaptive immune response, with CD4+ T-lymphocytes being the major players, has been clearly demonstrated. The requirement of IL-12 and IFN-gamma identifies this response as a Th1-dominated reaction. IFN-gamma is also important in the early phase of the host-parasite interaction. We analysed the outcome of infection in IL-12p40 (IL-12KO) and IFN-gamma (GKO) deficient C57BL/6 mice after primary and secondary challenge with the parasite and, for the first time, we demonstrate the resulting Ig response in sera an…
Costimulatory signalling potential of murine MHC class II‐positive T‐clone cells
1996
Activated human and rat T cells as well as mouse T-cell clones have been reported to synthesize and express major histocompatibility complex (MHC) class II molecules. However, the capacity of class II+ antigen (Ag) presenting T cells to induce proliferation of Ag-specific cloned T cells has been controversial. We analysed whether the failure of some T-cell clones to proliferate in response to Ag presented by class II+ T cells is because of a lack of costimulatory cytokine production by the antigen-presenting cells (APC). As a model system the mouse class II+ cloned BI/O4.1 T cells were used as APC in order to activate the T cell clone KIII5. This T-helper 1 (Th1) type, GAT (synthetic copoly…
Interferon-regulatory factor 4 is essential for the developmental program of T helper 9 cells.
2010
Summary Interferon-regulatory factor 4 (IRF4) is essential for the development of T helper 2 (Th2) and Th17 cells. Herein, we report that IRF4 is also crucial for the development and function of an interleukin-9 (IL-9)-producing CD4 + T cell subset designated Th9. IRF4-deficient CD4 + T cells failed to develop into IL-9-producing Th9 cells, and IRF4-specific siRNA inhibited IL-9 production in wild-type CD4 + T cells. Chromatin-immunoprecipitation (ChIP) analyses revealed direct IRF4 binding to the Il9 promoter in Th9 cells. In a Th9-dependent asthma model, neutralization of IL-9 substantially ameliorated asthma symptoms. The relevance of these findings is emphasized by the fact that the ind…