Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: HUMANGGP:021712 (IL-6)
 58,419 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of IL-10 on the generation of alloreactivity in primary mixed lymphocyte cultures (MLCs) were investigated. IL-10 inhibited in a dose-dependent fashion the alloantigen-induced proliferative responses. The suppressive effect was maximal when IL-10 was added at the beginning of the cultures, suggesting that it acts on the early stages of T cell activation. The proliferative responses were enhanced in the presence of a neutralizing anti-IL-10 mAb, indicating that endogenously produced IL-10 suppresses proliferation in primary MLC. The inhibitory effects of IL-10 were observed irrespective of whether irradiated allogeneic peripheral blood mononuclear cells, purified monocytes or freshly isolated B cells were used as stimulator cells. The proliferation of both the CD4+ and CD8+ T cell subsets was inhibited to a similar extent. The reduced proliferative responses were only minimally restored by high concentrations of exogenous IL-2, indicating that the effects of IL-10 are not exclusively due to inhibition of IL-2 synthesis. Furthermore, the production of IL-2, interferon (IFN)-gamma, IL-6, granulocyte macrophage colony stimulating factor, and tumor necrosis factor-alpha in primary MLCs was diminished by IL-10 and enhanced in the presence of anti-IL-10 mAb. The strongest effects were observed on the production of IFN-gamma. Although IL-10 reduces the proliferative responses, the ratios of CD3+CD4+ and CD3+CD8+ T cells remained the same in IL-10 treated and control cultures, yet the percentages of activated CD3+ T cells, as judged by CD25 and HLA-DR expression, were consistently reduced.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interleukin 10 inhibits allogeneic proliferative and cytotoxic T cell responses generated in primary mixed lymphocyte cultures. 128 62

The effects of Staphylococcus aureus enterotoxin A (SEA) and lipopolysaccharide (LPS) in cytokine production were assessed at the single cell level in cells obtained from healthy blood donors. Cytokine production was studied with UV-microscopy of fixed and permeabilized cells stained with cytokine specific monoclonal antibodies. The cytokines evaluated included tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, IL-2, IL-4, interferon (IFN)-gamma and TNF-beta. LPS exhibited marked production of IL-1 alpha, IL-1 beta, TNF-alpha, IL-6 and IL-8. After LPS stimulation IL-1 alpha, IL-1 beta, TNF-alpha and IL-8 were the dominating products, all peaking at or before 4 hours after cell stimulation. In addition, IL-10 production was evident after 12 hours of cell stimulation. The T-lymphocyte-derived cytokines TNF-beta, IL-2, IFN-gamma and IL-4 were never detected in the cultures. All cytokine production, except IL-8, was downregulated at 96 hours. In contrast, peak production of IL-1 alpha, IL-1 beta and IL-8, which were the dominant products, occurred after 12 hours in the SEA-stimulated cultures. Further, a significant T-lymphocyte production of TNF-beta, TNF-alpha, IFN-gamma and IL-2 was found with peak production 12-48 hours after initiation. Only low amounts of IL-6 were evident. The two types of cytokine pattern and kinetics found may correspond to the different clinical conditions after invasive Gram-negative Escherichia coli vs Gram-positive Staphylococcus aureus infections in humans, with a much more rapid onset of disease after E. coli infections.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endotoxin and Staphylococcus aureus enterotoxin A induce different patterns of cytokines. 129 33

We have investigated the proliferative response of thymocytes from different mouse strains to cytokines in vitro. Interleukin 2 (IL-2), IL-4 and IL-7 induced proliferation of thymocytes from NMRI/KI (a locally bred NMRI mouse strain), NMRI/H ('traditional' NMRI mice), C3H/HeJ and C3H/HeN mice. NMRI/KI thymocytes showed the most prominent proliferation in response to IL-1 alpha and IL-1 beta. IL-3, IL-5, IL-6, IL-8, IL-10, tumour necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), inhibin and lipopolysaccharide (LPS) induced no thymocyte proliferation. Germfree NMRI/KI mouse thymocytes showed a significantly lower proliferation in response to IL-1 alpha and IL-1 beta than conventional mice. Rat tissues, previously shown to contain lymphocyte activating factors (LAFs), were also tested. Skin, tongue, esophagus, proventricular stomach, testis and placenta were all positive in the LAF assay utilizing NMRI/KI thymocytes, whereas none of the tissue extracts could induce proliferation in NMRI/H thymocytes. The higher cytokine responsiveness in conventional mice compared with germfree might suggest that exposure to microflora induces a higher state of activation of the immune system. The LAF assay, utilizing NMRI/KI thymocytes, is a highly sensitive IL-1 bioassay with a detection level of 1 pg/ml for IL-1 beta and 2 pg/ml for IL-1 alpha. The specificity of the assay is increased by utilizing NMRI/H mice to exclude the presence of IL-2, IL-4 and IL-7.
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PMID:Cytokine responsiveness in germfree and conventional NMRI mice. 129 36

A recent addition to the lymphokine network is human IL-10 (hIL-10). This novel lymphokine has striking homology to BCRF1 protein, the product of a previously uncharacterized open-reading frame in the Epstein-Barr virus (EBV) genome. To date, IL-10 expression has been described in several T clones induced with anti-CD3 and phorbol myristate acetate (PMA), in monocytes stimulated with lipopolysaccharide (LPS), and in murine B-cell lymphomas. We sought to determine whether human B cells express hIL-10 and, if so, its relationship to EBV and to other B-cell lymphokines. We studied 21 EBV-positive B-cell lines derived from patients with acquired immunodeficiency syndrome (AIDS) and Burkitt's lymphoma (n = 6), American Burkitt's (n = 3), African Burkitt's (n = 5), and normal lymphoblastoid cell lines (n = 7), in comparison with seven EBV-negative cell lines. All cell lines were activated with the tumor promoters PMA and teleocidin and were studied by Northern blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme-linked immunoadsorbent assay (ELISA). We demonstrated that EBV-positive cell lines derived from patients with American Burkitt's lymphoma, and especially those from patients with AIDS, constitutively express large quantities of hIL-10 by Northern blot analysis and ELISA (range, 3,101 to 25,915 pg/mL), and that both teleocidin and PMA induce hIL-10 in these cell lines. In contrast, six of seven EBV-negative cell lines did not express hIL-10 even by RT-PCR, and hIL-10 was not triggered by PMA or teleocidin. To assure that the 350 bp amplified by PCR was hIL-10 and not BCRF1, we used PCR primers, which do not amplify a fragment from plasmid templates containing BCRF1. Cloning and sequencing of the 350 bp product also demonstrated that B-cell IL-10 is identical to hIL-10 from the T-cell clone B21. Correlation of hIL-10 with other B-cell lymphokines secreted by these B-cell lines demonstrated that hIL-10 secretor cell lines also constitutively secrete or can be induced to secrete IL-6, although to a much lesser amount. Since both lymphokines influence B-cell growth and differentiation, we suggest that hIL-10 may contribute to the polyclonal B-cell activation and hyperglobulinemia seen in AIDS patients. Finally, several reports support the hypothesis that EBV is an important cofactor in the development of human immunodeficiency virus type 1 (HIV-1)-related B-cell lymphomas. Detection of large quantities of hIL-10 in B-cell lines derived from AIDS patients, the close association between EBV and hIL-10 shown in this report, and the ability of BCRF1 to capture hIL-10 activities, make hIL-10/BCRF1 an attractive candidate as a factor causing B-cell growth and immortalization in patients with AIDS and B-cell lymphomas.
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PMID:Human B-cell interleukin-10: B-cell lines derived from patients with acquired immunodeficiency syndrome and Burkitt's lymphoma constitutively secrete large quantities of interleukin-10. 842 93

Parasites may employ particular strategies of eluding an immune response by taking advantage of those mechanisms that normally guarantee immunological self-tolerance. Much in the way as it occurs during the establishment of self-tolerance, live pathogens may induce clonal deletion, functional inactivation (anergy) and immunosuppression. At this latter level, it appears that certain pathogens produce immunosuppressive cytokine-like mediators or provoke the host to secrete cytokines that will compromise the anti-parasite immune response. It appears that immune responses that preferentially involve T helper 1 cells (secretors of interleukin-2-and interferon-gamma) tend to be protective, whereas T helper 2 cells (secretors of IL-4, IL-5, IL-6, and IL-10), a population that antagonizes T helper cells, mediate disease susceptibility and are involved in immunopathological reactions. Cytokines produced by T helper 2 cells mediate many symptoms of infection, including eosinophilia, mastocytosis, hyperimmunoglobulinemia, and elevated IgE levels. Administration of IL-2 and IFN-gamma has beneficial effects in many infections mediated by viruses, bacteria, and protozoa. The use of live vaccinia virus might be an avenue for the treatment of or the vaccination against infection. We have found that a vaccinia virus expressing the gene for human IL-2, though attenuated, precipitates autoimmune disease in immunodeficient, athymic mice. Thus, although T helper 1 cytokines may have desired immunostimulatory properties, they also may lead to unwarranted autoaggressive responses.
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PMID:Coevolution of hosts and microorganisms: an analysis of the involvement of cytokines in host-parasite interactions. 134 5

Progressive lymphoproliferation and increasingly severe immunodeficiency are prominent features of a syndrome, designated mouse AIDS, which develops in susceptible strains of mice infected with the mixture of murine leukemia viruses, termed LP-BM5. Development of splenomegaly and lymphadenopathy, caused primarily by increases in B cell immunoblasts, requires the presence of CD4+ T cells and is assumed to be mediated by lymphokines produced by these cells inasmuch as progression of disease is markedly inhibited by treatment of infected mice with cyclosporin A. Studies of spleen cells from infected mice revealed spontaneous production of cytokines (IFN-gamma, IL-2, IL-4, IL-5, and IL-10) characteristic of Th0 (or a mixture of Th1 and Th2) T helper cells at 1 wk after infection. At later times, IFN-gamma and IL-2, characteristic products of Th1 helper clones, were expressed poorly, either spontaneously or after stimulation of cells with Con A. In contrast, IL-4, IL-5, IL-6, and IL-10, cytokines typically synthesized by Th2 cells, were produced in response to Con A or spontaneously through 18 wk post-infection. Increased serum IgE levels and enhanced IL-10 mRNA expression were consistent with expression of Th2 cytokines at biologically significant levels in vivo. Selective depletion of T cell subsets before stimulation with Con A showed that CD4+ T cells were the primary source of IL-2, IL-4, IL-10, and, to a lesser extent, IFN-gamma in spleens and lymph nodes of normal or infected mice. These results suggest that persistent activation of CD4+ T cells with the lymphokine profile of Th2 helper clones is responsible for chronic B cell stimulation, down-regulation of Th1 cytokines, and impaired CD8+ T cell function in mouse AIDS. This provides the first demonstration that, like many parasitic infections, viruses encoding potent antigenic stimuli can markedly affect the balance of Th subset expression.
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PMID:CD4+ subset regulation in viral infection. Preferential activation of Th2 cells during progression of retrovirus-induced immunodeficiency in mice. 134 85

In the present article we show that supernatants derived from lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA)-stimulated A-20 B cell lymphoma are able to induce polyclonal immunoglobulin (Ig) secretion by normal B cells in a T-cell-dependent manner. This activity could be blocked by neutralizing monoclonal antibodies against interferon-gamma, but not by monoclonal antibodies against interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10 and granulocyte macrophage colony-stimulating factor (GM-CSF) or even a polyclonal antibody against tumor necrosis factor (TNF)-alpha. Furthermore, A-20 supernatants induced the production of measurable amounts of interferon-gamma by normal murine spleen cells and activates natural killer (NK) cells. Fractionation of factor-rich supernatants on a Sephacryl S-200 column revealed that the factor activity is located in the fractions corresponding to a molecular mass of 160-150 kDa and 80-70 kDa. The biological activities found in the A-20 supernatant are very similar to the ones described for the recently cloned human IL-12/NK cell stimulatory factor. These results suggest the existence of a murine analogous factor for the human IL-12 produced by A-20 B cell lymphoma.
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PMID:An activated murine B cell lymphoma line (A-20) produces a factor-like activity which is functionally related to human natural killer cell stimulatory factor. 135 72

To determine the role of germline epsilon transcription in IgE synthesis, the effects of cytokines on germline epsilon RNA synthesis in IL-4 dependent epsilon switching in B cells was investigated. Induction of germline epsilon transcription in highly purified B cells seems to be a specific property of IL-4, since none of the other cytokines tested [IL-1 alpha, beta, IL-2, IL-3, IL-5, IL-6, IL-7, IL-9, IL-10, G-CSF, GM-CSF, M-CSF, IFN-gamma, IFN-alpha, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-beta] were effective. TGF-beta, IFN-gamma, and IFN-alpha inhibit IL-4 dependent IgE synthesis, but only TGF-beta blocked germline epsilon RNA synthesis in purified B cells, indicating that this may be the mechanism by which TGF-beta inhibits IgE synthesis, and that IFN-gamma and IFN-alpha act on other stages of the regulatory process resulting in IgE production. IL-5, IL-6, and TNF-alpha enhance IL-4 dependent IgE synthesis, but only TNF-alpha enhanced IL-4 induced germline epsilon RNA synthesis. Finally, anti-CD40 mAbs and the non-IL-4 producing CD4+ T cell clone A3, which in the presence of IL-4 induce IgE synthesis by purified B cells, both strongly enhanced germline epsilon transcription. These data, together with the observation that epsilon switching in cultures initiated with single sIgM+, sIgE- B cells in all instances was preceded by germline epsilon RNA synthesis, indicate that there is a strong relationship between germline epsilon transcription and IgE synthesis.
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PMID:Modulation of IL-4 induced germline epsilon RNA synthesis in human B cells by tumor necrosis factor-alpha, anti-CD40 monoclonal antibodies or transforming growth factor-beta correlates with levels of IgE production. 137 45

The anamnestic response to infection with Listeria monocytogenes is characterized by the rapid elimination of normally lethal doses of bacteria and accelerated granuloma formation. These phenomena are mediated by listeria-specific memory T cells within the first 24 h after reinfection. In order to elucidate the mechanisms operative during this decisive phase of infection, we conducted a comprehensive kinetic and quantitative analysis of cytokine gene expression in the livers of naive and immune mice. Organs were removed at 30 min, and 1, 2, 6, and 24 h after primary and secondary infections, and PCR3-assisted messenger RNA (mRNA) amplification was performed on matched samples using primers specific for IL-1 beta, IL-6, M-CSF, GM-CSF, TNF-alpha, IFN-gamma, IL-10, IL-4, IL-2, IL-3 and I1-2Rp55. The cytokine pattern characteristic of secondarily infected animals differed qualitatively by the expression of mRNA for IL-2, IL-2Rp55, IL-3, and IL-4, demonstrating the accumulation and activation of specific T cells in the livers as early as 1 to 2 h after reinfection. Combined in vivo depletion of both CD4+ and CD8+ T cells before reinfection almost completely abrogated the differentiated cytokine profile typical of the anamnestic response. Using competitive PCR for semiquantitative determination of mRNA levels, the amount of IL-1 beta and IL-6 mRNA was found to be very similar during primary and secondary infection, whereas TNF-alpha mRNA was found to be increased by approximately 10-fold 2 h and IFN-gamma mRNA by approximately 50 to 100-fold 6 h after reinfection when compared with a primary challenge. Combined in vivo depletion of both CD4+ and CD8+ T cells before reinfection resulted in a substantial (approximately 10-fold) decrease in IFN-gamma mRNA expression. To correlate these findings with cytokine secretion, spleen cells from naive and immune as well as normal and CD4+ and CD8+ cell depleted mice infected 6 h previously were cultured for 48 h, and supernatants were analyzed for the amount of the above mentioned cytokines. Semiquantitative PCR-assisted mRNA amplification is demonstrated to be a superior tool in dissociating the mediators of innate resistance from those operative in protective immunity and granuloma formation.
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PMID:Kinetic analysis of cytokine gene expression in the livers of naive and immune mice infected with Listeria monocytogenes. The immediate early phase in innate resistance and acquired immunity. 140 26

Reactional states in leprosy are produced by different immunologic mechanisms and are responsible for a major component of tissue damage of the disease. Reversal reactions exhibit increased CD4 T cell infiltration in lesions and augmented cell-mediated immune reactivity to Ag of Mycobacterium leprae that can rapidly produce nerve damage. Erythema nodosum leprosum (ENL) reactions also have CD4 T cell infiltration but appear to be associated with the formation of immune complexes that are responsible for panniculitis, arthritis, vasculitis, and nerve injury. Because these reactional states may serve as paradigms for other types of human immunologically mediated tissue damage, this study sought to characterize the dynamic changes in cytokines associated with these reactions. Expression of cytokine mRNA in lesions of leprosy reactional states were measured by PCR. In reversal reactions, IL-1 beta, TNF-alpha, IL-2, and IFN-gamma mRNA were prominent and found to increase during the reaction, concomitant with decreases in expression of mRNA for IL-4, IL-5, and IL-10. In ENL, selective increases in the expression of IL-6, IL-8, and IL-10 mRNA was observed, with persistent expression of IL-4 and IL-5 mRNA. Reversal reactions represent naturally occurring delayed-type hypersensitivity reactions that favor macrophage activation and protective immunity, but which can engender concomitant cell injury. In contrast, ENL lesions represent immediate-type hypersensitivity reactions reflecting the selective stimulation of cytokines that attract neutrophils, stimulate antibody production, and down-regulate macrophage activation. The analysis of cytokine dynamics within different inflammatory responses can provide insights into immune mechanisms of tissue damage, and provide a useful framework for developing strategies for therapeutic intervention.
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PMID:Cytokine patterns of immunologically mediated tissue damage. 150 Jul 26


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