Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of transforming growth factor beta (TGF-beta) on interferon gamma-mediated killing of the intracellular protozoan parasite Trypanosoma cruzi and on the course of T. cruzi infection in mice were investigated. Spleen cells from mice with acute T. cruzi infections were found to produce elevated levels of biologically active TGF-beta in vitro, and the possibility that TGF-beta may mediate certain aspects of T. cruzi infection was then addressed. When mouse peritoneal macrophages were treated with TGF-beta in vitro, the ability of IFN-gamma to activate intracellular inhibition of the parasite was blocked. This occurred whether cells were treated with TGF-beta either before or after IFN-gamma treatment. TGF-beta treatment also blocked the T. cruzi-inhibiting effects of IGN-gamma on human macrophages. Additionally, treatment of human macrophages with TGF-beta alone led to increased parasite replication in these cells. The effects of TGF-beta on T. cruzi infection in vivo were then investigated. Susceptible C57BL/6 mice developed higher parasitemias and died earlier when treated with TGF-beta during the course of infection. Resistant C57BL/6 x DBA/2 F1 mice treated with TGF-beta also had increased parasitemias, and 50% mortality, compared with no mortality in infected, saline-treated controls. A single dose of TGF-beta, given at the time of infection, was sufficient to significantly decrease resistance to infection in F1 mice and to exacerbate infection in susceptible C57BL/6 mice. Furthermore, a single injection of TGF-beta was sufficient to counter the in vivo protective effects of IFN-gamma. We conclude that TGF-beta, produced during acute T. cruzi infection in mice, is a potent inhibitor of the effects of macrophage activating cytokines in vivo and in vitro and may play a role in regulating infection.
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PMID:Regulation of Trypanosoma cruzi infections in vitro and in vivo by transforming growth factor beta (TGF-beta). 190 9

Spleen cell populations depleted of both B and T lymphocytes produce interleukin 4 (IL-4) in response to stimulation with immunoglobulins bound to the surface of culture dishes. In the presence of interleukin 3 (IL-3), plate-bound (PB) IgE and PB-IgG1, IgG2a, and IgG2b are excellent stimulants, whereas PB-IgA and PB-IgM fail to stimulate IL-4 production. In the absence of IL-3, PB-IgE stimulates relatively modest production of IL-4, whereas PB-IgG2a generally does not. The response to PB-IgE is inhibited by soluble IgE; antibody to Fc gamma receptor II inhibits the response to PB-IgG2a. Thus, separate receptors mediate these stimulations, and Fc receptor cross-linkage is required for IL-4 production. Depletion of cells expressing asialo-GM1 does not diminish IL-4 production in response to PB immunoglobulins, indicating that natural killer cells are not essential for non-B, non-T cell production of IL-4. In addition to IL-4, non-B, non-T cells produce IL-3, but no detectable interleukin 2 or interferon gamma. Non-B, non-T cells may be an important source of lymphokines in a variety of immune responses and may serve to amplify the effects of T cells of the TH2 type.
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PMID:Cross-linking Fc receptors stimulate splenic non-B, non-T cells to secrete interleukin 4 and other lymphokines. 210 35

Spleen cell cultures derived from animals infected 6 d earlier with Listeria monocytogenes produced 10-20-fold more murine interferon gamma (MuIFN gamma) than spleen cells from nonimmune mice in response to stimulation with T cell mitogens. A striking temporal association was found between the enhanced synthesis of MuIFN gamma and the development of anti-Listeria immunity in that both the potential for increased MuIFN gamma production and the generation of Listeria-protective T cells developed and then decayed in unison. Treatment of spleen cells with monoclonal anti-Thy-1.2 plus complement virtually abolished the ability of cells from Listeria-immune mice to synthesize MuIFN gamma. The T cells producing MuIFN gamma were found to be more susceptible to complement-mediated lysis with monoclonal anti-Lyt-1.2 than with monoclonal anti-Lyt-2.2. The production of MuIFN gamma was not affected by treating spleen cells with anti-IgG antisera or with a monoclonal antibody directed against I-A specificities. MuIFN gamma was detected 4 h after the beginning of mitogenic stimulation of spleen cell cultures, and peak levels of MuIFN gamma were reached by 18 h. The IFN synthesized by mitogen-induced spleen cells derived from Listeria-immune mice were relatively labile at pH 2.0 and neutralized by a rabbit anti-MuIFN gamma serum but not by an antiserum having specificities for MuIFN alpha and MuIFN beta. The apparent molecular weight of the MuIFN gamma, as estimated by molecular sieving on a Bio-gel P-60 column, was estimated to be 38,000, and the isoelectric point as determined by chromatofocusing was extremely heterogeneous, ranging between pH 5.0 and pH 7.0.
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PMID:Enhanced production of murine interferon gamma by T cells generated in response to bacterial infection. 617 17

The T-cell response to mutated and normal p53 products of BALB/c-derived Meth A sarcoma was analyzed. Meth A p53 is known to have three missense point mutations in codons 132, 168, and 234, and 24 peptides containing wild-type or mutated sequences at the three mutation sites were constructed. Spleen cells from BALB/c or (BALB/c x C57BL/6)F1 mice immunized with p53 peptides were sensitized in vitro with the corresponding peptides. Because Meth A is resistant to cytotoxic T cells, the sensitive P1-HTR cell line, which expresses a low level of p53 lacking the Meth A p53 mutations, was chosen as a target, either pulse-labeled with p53 peptides or transfected with plasmids containing coding sequences from Meth A p53. One peptide, a nonamer containing the codon 234 mutation (234CM), induced CD8+ cytotoxic T cells that lysed 234CM-pulsed P1-HTR cells in an H-2Kd-restricted fashion. P1-HTR cells pulsed with the corresponding wild-type peptide were only weakly lysed by 234CM-reactive cytotoxic T cells. P1-HTR cells pulsed with other wild-type or mutated p53 peptides were not lysed by 234CM-reactive cytotoxic T cells, nor could these peptides, including 234CW (the wild-type counterpart to 234CM), elicit cytotoxic cells. P1-HTR cells transfected with plasmids coding for the 234CM sequence and expressing high p53 levels were weakly lysed by 234CM-reactive cytotoxic T cells. However, lysis of one of the transfectants was significantly increased by pretreatment with interferon gamma. A proliferative response of CD4+ T cells was elicited by immunization with 234CM and 234CW, but not with other p53-related peptides. The specificity of 234CM-induced CD4+ T cells for 234-region peptides was broader than the reactivity of 234CM-reactive cytotoxic T cells. Mice immunized with 234CM in incomplete Freund's adjuvant showed heightened resistance to Meth A challenge.
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PMID:A mouse mutant p53 product recognized by CD4+ and CD8+ T cells. 790 59

During the time of egg deposition, schistosome-infected mice exhibit a downregulation in interleukin 2 and interferon gamma production toward parasite antigens, mitogens, and foreign nonparasite protein antigens. To determine whether this imbalance in cytokine response would impact on CD8+ cytotoxic T-lymphocyte (CTL) responses, as well as on immune clearance of viral infections, we challenged Schistosoma mansoni-infected BALB/c mice, when cytokine imbalance was prominent, with a recombinant vaccinia virus expressing human immunodeficiency virus type 1 gp160. In contrast to control vaccinia-infected animals, S. mansoni plus vaccinia-infected mice did not produce significant Th1 cytokine responses upon in vitro stimulation with recombinant gp120, consistent with previous results for nonparasite antigens. However, more striking was the downregulation of the virus-specific CTL response not previously studied. Spleen cells from vaccinia-infected control mice displayed strong CD8+ cytolytic activity against gp160-transfected fibroblasts and fibroblasts pulsed with a peptide (P18) representing a CTL epitope of gp160. In contrast, mice coinfected with S. mansoni and vaccinia manifested absent or markedly reduced in vitro CTL activity even in the presence of exogenous interleukin 2. To determine whether this immune dysregulation might impact on viral clearance, we measured virus titers in tissues as a function of time. Mice infected with vaccinia virus alone rapidly cleared the virus, whereas in animals coinfected with S. mansoni, viral clearance was delayed by as much as 3 weeks in the liver and by several days in the spleen and lungs. These observations suggest that helminth infection may influence immune responses to concurrent viral infections.
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PMID:Helminth infection results in decreased virus-specific CD8+ cytotoxic T-cell and Th1 cytokine responses as well as delayed virus clearance. 809 48

We previously reported that the extract of seeds from Aeginetia Indica L (AIL), a parasitic plant, induces potent antitumor immunity in tumor-bearing mice and that CD4+ T cells appear to be the main contributors in the induction of antitumor resistance. The present study was set up to investigate the in vitro effects of AIL on various lymphoid cells. Spleen cells from mice pretreated with AIL every 2 days for 1 week produced interleukin 2 (IL-2), interferon gamma (IFN gamma), tumor necrosis factor (TNF) and interleukin 6 (IL-6) when these cells were stimulated in vitro by AIL. Further, we found that CD4+ T cells were main producers of IL-2 and TNF upon the stimulation with ALL in vitro, while both CD4+ and CD8+ T cells secreted IFN. On the other hand, ALL was mitogenic in vitro to T enriched splenic lymphocytes as well as B enriched splenic lymphocytes. Moreover, AIL also proliferated thymocytes and this activity was potently synergistic with a suboptimal dose of concanavalin A (Con A). Lipopolysaccharide (LPS) contamination in AIL preparation was negligible since proliferative activity of AIL to B enriched splenic lymphocytes was not influenced in the presence of an endotoxin antagonist, polymyxin B sulfate (PMB). Further, B cell mitogenic activity of AIL seems to be mediated by different mechanism(s) from that of LPS since ALL could proliferate B enriched lymphocytes of C3H/HeJ mice which do not respond to the stimulation with LPS. A well known biological response modifier (BRM), Krestin (PSK), had no ability in inducing either T or B lymphocyte activation in vitro as shown by AIL.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Seed extract of Aeginetia indica L induces cytokine production and lymphocyte proliferation in vitro. 820 51

To gain a better understanding of inherent gender-related effects on autoimmunity, cytokine genes were examined in female and male New Zealand Black X New Zealand White (B/W) mice, which are a murine model of systemic lupus erythematosus (SLE). In preliminary studies, semiquantitative reverse transcriptase-polymerase chain reaction analysis showed a trend for B/W spleen cell interferon gamma (IFN-gamma) mRNA in B/W female spleen cells to exceed that of males. This difference was obliterated following concanavalin A (Con A) stimulation. Spleen cells from B/W mice of both sexes were then examined at 6, 18, and 27 weeks of age, and results were compared with matched groups of nonautoimmune DBA/2 mice. Pooled splenocytes from all 12 groups of animals were compared simultaneously for expression of mRNA specific for IFN-gamma, interleukin 4 (IL-4) and interleukin 6 (IL-6). Strain was a potent influence on cytokine transcripts. In unstimulated splenocytes from female and male B/W mice, there was a notable trend for IFN-gamma and IL-6 mRNA expression to exceed transcripts from nonautoimmune DBA/2 mice. When comparisons were carried out by gender, a highly significant increase of IFN-gamma transcripts was apparent in B/W females compared to B/W males at the age of 27 weeks. Following Con A incubation, strain and gender differences were eliminated. IL-4 transcript expression was similar in all pools of cells, and age was not an important factor in expression of any transcript. This study represents the first examination of multiple cytokine transcripts in lymphoid cells from B/W mice. In this hormone-sensitive model of SLE, strain and gender determined in vivo expression of IFN-gamma and IL-6 mRNA.
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PMID:Cytokine mRNA expression in the B/W mouse model of systemic lupus erythematosus--analyses of strain, gender, and age effects. 928 84

The production and role of endogenous cytokines during the course of secondary Corynebacterium (C.) pseudotuberculosis infection were investigated in mice. When immunized mice were challenged on day 28 after primary infection, tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) were found to appear at 3 hr and to reach the maximum at 24 hr after challenge. Spleen cells of mice primarily infected from 2 to 8 weeks before produced a significant amount of TNF-alpha and IFN-gamma when stimulated with formalin-killed bacteria. However, they could not produce detectable amounts of IL-4. The administration of anti-TNF-alpha monoclonal antibody (MAb) and IFN-gamma MAb increased bacterial proliferation in the organs of immune mice and exacerbated the secondary infection. Injection of anti-CD4 MAb alone or anti-CD4 plus anti-CD8 MAbs resulted in significantly increased mortality and a marked suppression of bacterial elimination as well as cytokine production of secondarily infected mice, while the treatment with anti-CD8 MAb alone showed no effect on either the resistance or cytokine production of mice. These results suggest that CD4, probably Th1 T cells, play an important role for establishment of protective immunity against secondary C. pseudotuberculosis infection by secreting TNF-alpha and IFN-gamma.
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PMID:Tumor necrosis factor alpha and gamma interferon are required for the development of protective immunity to secondary Corynebacterium pseudotuberculosis infection in mice. 1059 77

Interleukin 18 (IL-18) reportedly synergizes with IL-12 and IL-10 for interferon gamma (IFN-gamma) synthesis and natural killer (NK) cell activity, respectively. Here we show that IL-18 alone induces low level IFN-gamma production by unstimulated Balb/c mouse spleen cells, but production is enhanced synergistically in cocultures of spleen cells and allogeneic living or fixed Yac-1 cells. Spleen cells could be primed with IL-18 prior to coculture with Yac-1 cells for IFN-gamma production, which also was observed in cocultures containing either syngeneic or xenogeneic tumor cells. IFN-gamma production in stimulated cocultures was abrogated almost completely by anti-IL-12 antibody and was unrelated to spleen cell lytic activity. IL-10 moderately inhibited IFN-gamma production induced by IL-18. Therefore, in spleen cell and tumor cell cocultures exposed to IL-18, high levels of IFN-gamma are produced by the spleen cells arising from a synergistic interaction between the exogenous IL-18 and endogenous IL-12; however, this activity is unrelated to the spleen cell lytic activity.
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PMID:Interleukin 18 induces a synergistic enhancement of interferon gamma production in mixed murine spleen cell-tumor cell cultures: role of endogenous interleukin 12. 1097 85

Granulocyte colony-stimulating factor (G-CSF) administration in vivo has been shown to improve the defence mechanisms against infection by different microbes. Here we evaluated a possible protective role of this molecule in a mouse model of mycobacterial infection. The administration of recombinant G-CSF promoted an extensive blood neutrophilia but failed to improve the course of Mycobacterium avium infection in C57Bl/6 or beige mice. G-CSF administration also failed to improve the efficacy of a triple chemotherapeutic regimen (clarithromycin + ethambutol + rifabutin). G-CSF treatment did not protect interleukin-10 gene disrupted mice infected with M. avium. Spleen cells from infected mice treated with G-CSF had a decreased priming for antigen-specific production of interferon gamma compared to control infected mice. Our data do not substantiate previous reports on the protective activity of G-CSF in antimycobacterial immunity using mouse models.
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PMID:Effects of recombinant granulocyte-colony stimulating factor administration during Mycobacterium avium infection in mice. 1142


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