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Query: UNIPROT:P05231 (
interleukin-6
)
23,907
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The contribution of Epstein-Barr virus (EBV) strain variation to the pathogenesis of virus-associated tumours remains unknown. Given the central role of LMP1 in EBV-induced transformation, much interest has focused on the influence of LMP1 sequence variation on the signaling pathways and multiple downstream phenotypic consequences of LMP1 expression. The identification of LMP1 variants with a common 10-amino-acid deletion and additional point mutations (typified by the CAO-LMP1 isolate) in EBV strains associated with nasopharyngeal carcinoma prompted us to examine the effect of stable prototype B95.8-LMP1 and CAO-LMP1 expression on the phenotype and differentiation of SCC12F human epithelial cells. Both forms of LMP1 were able to induce expression of the antiapoptotic A20 protein and provide protection from tumour necrosis factor-alpha-induced cytotoxicity. Although B95.8-LMP1 induced growth inhibition, expression of certain cell surface molecules (
CD40
, CD44, and CD54), and secretion of
interleukin-6
and -8 in SCC12F cells, stable CAO-LMP1 expression failed to elicit these effects. Furthermore, B95. 8-LMP1, but not CAO-LMP1, induced alterations in cell morphology and blocked epithelial cell differentiation. Both B95.8-LMP1 and CAO-LMP1 induced similar levels of nuclear factor-kappaB activation, but the ability of CAO-LMP1 to activate the AP-1 pathway was relatively impaired. These data highlight significant functional differences between the prototype B95.8-LMP1 and the CAO-LMP1 variant when stably expressed in human epithelial cells and suggest that continued analysis of LMP1 variants will help to further dissect the signaling pathways activated by LMP1 as well as provide insights into the contribution of LMP1 sequence variation to the pathogenesis of EBV-associated tumours.
...
PMID:Identification of functional differences between prototype Epstein-Barr virus-encoded LMP1 and a nasopharyngeal carcinoma-derived LMP1 in human epithelial cells. 1087 63
Interleukin-17 is a T-cell-derived cytokine, detected in skin affected by allergic contact dermatitis and psoriasis, which regulates keratinocyte expression of adhesion molecules and chemokines. In this study, we have analyzed whether interleukin-17 production segregates with a particular T helper (Th) cell subset, and have examined the capacity of interleukin-17 to modulate the activation of keratinocytes induced by Th1 and Th2 cytokines. A panel of 80 nickel-specific CD4+ T cell clones (36 Th0, 30 Th1, and 14 Th2) was isolated from peripheral blood or lesional skin of allergic contact dermatitis patients. Significant amounts (> 50 pg per ml) of interleukin-17 were released by about 50% of activated Th0, Th1, and Th2 cells. Interleukin-17 alone and in cooperation with interleukin-4, or to a lesser extent with interferon-gamma, decreased the interleukin-1 receptor antagonist to interleukin-1alpha ratio in the supernatants as well as in cell lysates from keratinocytes. In addition, interleukin-17 stimulated the release of growth-regulated oncogene-alpha, granulocyte-macrophage colony stimulating factor, and
interleukin-6
, with synergistic or additive effects when used together with interferon-gamma or interleukin-4. Interleukin-17 and interleukin-4 also increased stem cell factor release, a function that was inhibited by interferon-gamma. Moreover, interleukin-17 and interleukin-4 enhanced interferon-gamma-induced expression of intercellular adhesion molecule 1, but not
CD40
, on keratinocytes. The constitutive expression of interleukin-17 and interferon-gamma receptors on keratinocytes was not modulated by interleukin-17, interferon-gamma, or interleukin-4, whereas the interleukin-4 receptor was significantly downregulated by interferon-gamma. As a whole, the results indicate that interleukin-17 can participate relevantly in T-cell-mediated skin immune responses by amplifying both interferon-gamma- and interleukin-4-induced activation of keratinocytes.
...
PMID:Interleukin-17 is produced by both Th1 and Th2 lymphocytes, and modulates interferon-gamma- and interleukin-4-induced activation of human keratinocytes. 1088 12
Recombinant adenovirus (rAd) infection is one of the most effective and frequently employed methods to transduce dendritic cells (DC). Contradictory results have been reported recently concerning the influence of rAd on the differentiation and activation of DC. In this report, we show that, as a result of rAd infection, mouse bone marrow-derived immature DC upregulate expression of major histocompatibility complex class I and II antigens, costimulatory molecules (
CD40
, CD80, and CD86), and the adhesion molecule CD54 (ICAM-1). rAd-transduced DC exhibited increased allostimulatory capacity and levels of
interleukin-6
(
IL-6
), IL-12p40, IL-15, gamma interferon, and tumor necrosis factor alpha mRNAs, without effects on other immunoregulatory cytokine transcripts such as IL-10 or IL-12p35. These effects were not related to specific transgenic sequences or to rAd genome transcription. The rAd effect correlated with a rapid increase (1 h) in the NF-kappaB-DNA binding activity detected by electrophoretic mobility shift assays. rAd-induced DC maturation was blocked by the proteasome inhibitor Nalpha-p-tosyl-L-lysine chloromethyl ketone (TLCK) or by infection with rAd-IkappaB, an rAd-encoding the dominant-negative form of IkappaB. In vivo studies showed that after intravenous administration, rAds were rapidly entrapped in the spleen by marginal zone DC that mobilized to T-cell areas, a phenomenon suggesting that rAd also induced DC differentiation in vivo. These findings may explain the immunogenicity of rAd and the difficulties in inducing long-term antigen-specific T-cell hyporesponsiveness with rAd-transduced DC.
...
PMID:Recombinant adenovirus induces maturation of dendritic cells via an NF-kappaB-dependent pathway. 1100 Feb 34
Murine dendritic cells (DCs) can be classified into at least 2 subsets, "myeloid-related" (CD11b(bright), CD8alpha(-)) and "lymphoid-related" (CD11b(dull), CD8alpha(+)), but the absolute relationship between the 2 remains unclear. Methods of generating DCs from bone marrow (BM) precursors in vitro typically employ granulocyte-macrophage colony-stimulating factor (GM-CSF) as the principal growth factor, and the resultant DCs exhibit a myeloidlike phenotype. Here we describe a flt3-ligand (FL)-dependent BM culture system that generated DCs with more diverse phenotypic characteristics. Murine BM cells cultured at high density in recombinant human FL for 9 days developed into small lymphoid-sized cells, most of which expressed CD11c, CD86, and major histocompatibility complex (MHC) class II. The CD11c(+) population could be divided into 2 populations on the basis of the level of expression of CD11b, which may represent the putative myeloid- and lymphoid-related subsets. The FL in vitro-derived DCs, when treated with interferon-alpha or lipopolysaccharide during the final 24 hours of culture, expressed an activated phenotype that included up-regulation of MHC class II, CD1d, CD8alpha, CD80, CD86, and
CD40
. The FL-derived DCs also exhibited potent antigen-processing and antigen-presenting capacity. Neutralizing anti-
interleukin-6
(
IL-6
) antibody, but not anti-GM-CSF, significantly reduced the number of DCs generated in vitro with FL, suggesting that
IL-6
has a role in the development of DCs from BM precursors. Stem cell factor, which exhibits some of the same bioactivities as FL, was unable to replace FL to promote DC development in vitro. This culture system will facilitate detailed analysis of murine DC development.
...
PMID:Generation of murine dendritic cells from flt3-ligand-supplemented bone marrow cultures. 1104 81
CD40
is a cell surface receptor initially discovered on cells of the hemopoietic lineage. Its primary role on immune cells is to enhance their activation and hence their production of cytokines and immunomodulatory molecules. Recently,
CD40
has also been detected on human fibroblasts. An emerging view of the fibroblast is that it is far more than a structural cell, being capable of intimate interaction with cells of the immune system. In fibroblasts from several tissues, the engagement of
CD40
with its ligand (CD40L) resulted in the secretion of proinflammatory molecules such as
interleukin-6
(
IL-6
) and IL-8. Currently, there are few data about the presence of the
CD40
-CD40L system in female reproductive tissues. This study investigates the expression of
CD40
by human endometrium, myometrium, and cervix both in situ and in tissue explant-derived fibroblasts.
CD40
was detected mainly in the perivascular region of endometrium, myometrium, and cervix. Light staining for
CD40
was observed in stromal elements. Additionally, the basal epithelium of cervix expressed
CD40
. Fibroblastic cells derived from all three sources express low levels of
CD40
, and this is up-regulated with interferon-gamma treatment (500 U/mL; 72 h). When activated with interferon-gamma and CD40L, the fibroblasts secreted increased amounts of
IL-6
, IL-8, and MCP-1. These data suggest that the
CD40
-CD40L system may provide a link between the resident structural cells of these reproductive tissues and the infiltrating immune cells or activated platelets that may express CD40L. The possible interaction of
CD40
with CD40L may be particularly important during events such as menstruation and cervical ripening, where up-regulation of the proinflammatory molecules
IL-6
and IL-8 is viewed as critical for these processes. In addition, dysregulation of this system may be a contributory factor to problems such as menstrual dysfunction and preterm labor.
...
PMID:Cd40 expression in uterine tissues: a key regulator of cytokine expression by fibroblasts. 1123 32
Polyclonal lymphocyte activation and hypergammaglobulinemia characterize the acute phase of Chagas' disease, a debilitating condition caused by Trypanosoma cruzi. Such pathogenic hyper-reactivities not only compromise specific host defense against the pathogen, but may also contribute to infection-induced chronic autoimmune responses. Recent studies showed that T. cruzi trans-sialidase (TS) directly stimulates the polyclonal proliferation and Ig secretion of normal murine B cells in a T-independent, Bruton's tyrosine kinase (Btk)-dependent manner. Related to this observation, we now show that parasite-derived and recombinant TS potentiate the proliferation and cytokine secretion of normal T cells triggered by antigen-specific and non-specific stimuli. TS potentiates T cell activation through stimulating B cells and macrophages, independent of
CD40
/CD40L and CD43 pathways. In contrast, optimal TS potentiation requires
interleukin-6
(
IL-6
) and Btk, as it is significantly reduced in splenocytes from
IL-6
-/- and Btk-defective Xid mice. The results suggest that TS, directly and indirectly, activates both antigen-presenting cell and T cell compartments, and that TS-induced
IL-6
may further amplify such activation. These observations open up the possibility that TS drives the polyclonal lymphocyte activation in acute T. cruzi infection, a phenomenon contributing to the pathogenesis of Chagas' disease.
...
PMID:Trypanosoma cruzi trans-sialidase potentiates T cell activation through antigen-presenting cells: role of IL-6 and Bruton's tyrosine kinase. 1146 7
Microglia are resident central nervous system (CNS) macrophages. Theiler's murine encephalomyelitis virus (TMEV) infection of SJL/J mice causes persistent infection of CNS microglia, leading to the development of a chronic-progressive CD4(+) T-cell-mediated autoimmune demyelinating disease. We asked if TMEV infection of microglia activates their innate immune functions and/or activates their ability to serve as antigen-presenting cells for activation of T-cell responses to virus and endogenous myelin epitopes. The results indicate that microglia lines can be persistently infected with TMEV and that infection significantly upregulates the expression of cytokines involved in innate immunity (tumor necrosis factor alpha,
interleukin-6
[IL-6], IL-18, and, most importantly, type I interferons) along with upregulation of major histocompatibility complex class II, IL-12, and various costimulatory molecules (B7-1, B7-2,
CD40
, and ICAM-1). Most significantly, TMEV-infected microglia were able to efficiently process and present both endogenous virus epitopes and exogenous myelin epitopes to inflammatory CD4(+) Th1 cells. Thus, TMEV infection of microglia activates these cells to initiate an innate immune response which may lead to the activation of naive and memory virus- and myelin-specific adaptive immune responses within the CNS.
...
PMID:Direct activation of innate and antigen-presenting functions of microglia following infection with Theiler's virus. 1155 11
An emerging concept is that fibroblasts are not homogeneous, but rather consist of subsets, capable of producing regulatory mediators that control regional inflammatory responses. Fibroblasts are key effector cells in Graves' ophthalmopathy, responsible for the connective tissue remodeling, and are a rich source of inflammatory mediators. The purpose of this research was to characterize subsets of the fibroblasts in the human orbit. The strategy used was to define fibroblast subpopulations based on surface expression of the Thy-1 antigen. Fibroblast strains derived from human orbital connective tissue exhibit heterogeneous Thy-1 expression. We show, for the first time, separation of orbital fibroblasts into functionally distinct Thy-1+ and Thy-1- subsets using magnetic beading techniques. Both subsets produced the pro-inflammatory cytokine
interleukin-6
(
IL-6
) after stimulation with IL-1beta or the
CD40
pathway, whereas Thy-1+ fibroblasts produced higher levels of prostaglandin endoperoxide H synthase-2 (PGHS-2) and prostaglandin E2 (PGE(2)). Thy-1- fibroblasts produced more IL-8 than Thy-1+ fibroblasts, and when treated with interferon-gamma (IFN-gamma) up-regulated MHC class II expression more robustly. Furthermore,
CD40
was expressed in a bimodal distribution within each fibroblast subset. These observations suggest that fibroblast subsets in the human orbit play distinct roles in the regulation of immune and inflammatory responses crucial in the initiation and development of thyroid-associated ophthalmopathy.
...
PMID:Fibroblast subsets in the human orbit: Thy-1+ and Thy-1- subpopulations exhibit distinct phenotypes. 1181 66
CD40
-induced activation of cytokine gene expression in dendritic cells (DC) is an important process in the initiation of primary immune responses. We have determined the intracellular signaling events that lead to
CD40
ligation-induced activation of
interleukin-6
(
IL-6
) gene transcription in a murine DC line, FSDC, that is phenotypically representative of bone marrow-derived DC.
IL-6
reverse transcriptase-PCR and promoter assays established the responsiveness of FSDC to anti-
CD40
ligation. Further promoter assays showed that the transcription factors NF-kappaB and AP-1 are downstream transcriptional mediators of
CD40
-induced
IL-6
gene expression. Anti-
CD40
treatment of FSDC stimulated increased expression of specific NF-kappaB (p50:p65) and AP-1 (c-Jun, JunB, JunD, and c-Fos) DNA-protein complexes. Overexpression of an IkappaB-alpha super-repressor or a dominant negative JunD resulted in a strong inhibition of
CD40
-inducible
IL-6
promoter activity supporting a role for both transcription factors. Upstream signal transduction events were studied by transfection of wild type and mutant human
CD40
expression constructs into FSDC followed by stimulation with an anti-human
CD40
antibody. These experiments revealed that anti-
CD40
stimulation of NF-kappaB and
IL-6
gene transcription requires specific amino acid residues in the cytoplasmic region of
CD40
involved in the recruitment of TRAF2. Induction of
IL-6
mRNA by anti-
CD40
treatment was found to be a transient event (24 h) and was followed by a diminution of
IL-6
transcript to levels below those found in unstimulated cells. This loss of
IL-6
expression was associated with reduced p50:p65 NF-kappaB DNA binding and elevated binding of CBF1 to a site overlapping the NF-kappaB site. Overexpression of CBF1 resulted in a profound inhibition of basal and anti-
CD40
-induced
IL-6
promoter activities indicating that prolonged induction of CBF1 may contribute to the transient nature of the
IL-6
response. The physiological relevance of these molecular events to DC function is discussed.
...
PMID:CD40 induces interleukin-6 gene transcription in dendritic cells: regulation by TRAF2, AP-1, NF-kappa B, AND CBF1. 1188 48
We studied concentration, phenotype, and function of peripheral blood (PB) dendritic cells (DCs) from patients with multiple myeloma (MM). The absolute number of circulating precursors of myeloid and plasmacytoid DCs was significantly lower in MM patients than in healthy subjects. After maturation, PBDCs from MM patients showed significantly lower expression of HLA-DR,
CD40
, and CD80 antigens and impaired induction of allogeneic T-cell proliferation compared with controls. Remarkably, they were not capable of presenting the patient-specific tumor idiotype to autologous T cells. Conversely, DCs generated in vitro from CD14(+) monocytes from the same patients, and PBDCs freshly isolated from healthy donors efficiently stimulated allogeneic and autologous T cells. To clarify the mechanism of PBDC deficiency in MM, we investigated the effects of the main plasma cell growth factor,
interleukin-6
(
IL-6
), on the development of DCs from CD34(+) cells.
IL-6
inhibited the colony growth of CD34(+) DC progenitors and switched the commitment of CD34(+) cells from DCs to CD14(+) CD1a(-) CD86(-)CD80(-)
CD40
(+/-)HLA-DR +/- monocytic cells exerting potent phagocytic activity but no antigen-presentation capacity. This effect was reversed by anti-
IL-6
antibodies. Growing CD34(+) cells in the presence of autologous serum (without
IL-6
) also suppressed the development of functional DCs. This study demonstrates that PBDCs from MM patients are functionally defective, partially because of
IL-6
-mediated inhibition of development. This brings into question the advisability of using PBDCs as antigen carriers for immunotherapy trials in MM. The results also suggest a novel mechanism whereby myeloma cells escape immune recognition.
...
PMID:Dendritic cells are functionally defective in multiple myeloma: the role of interleukin-6. 1207 32
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