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)

We have previously shown that following oral administration of myelin basic protein (MBP), regulatory T cells are generated from gut-associated lymphoid tissue and that these cells suppress experimental allergic encephalomyelitis (EAE). These regulatory T cells produce transforming growth factor-beta (TGF-beta) with various amounts of IL-4 and IL-10 and these TGF-beta-secreting T cells have been termed Th3 cells. T cells in lymphoid organs drained by mucosal sites secrete IL-4 as a primary T cell growth factor. In the present study, we examined the role of IL-4 on oral tolerance and in the generation of TGF-beta secreting cells. Treatment of (PLJ x SJL)F1 mice with intraperitoneal (i. p.) IL-4 and low-dose oral MBP (0.5 mg) given three times reduced the severity of EAE, whereas i.p. injection of IL-4 alone or oral MBP alone given in these suboptimal doses, showed no protection. Spleen cells from protected mice produced increased amounts of TGF-beta and reduced IFN-gamma upon stimulation with MBP in vitro. Mucosal MBP-specific IgA production was significantly increased in IL-4 plus MBP fed animals. Moreover, oral administration of IL-4 (1 microg per feeding) also enhanced the suppression of EAE by oral MBP and this protective effect was reversed by administration of anti-TGF-beta antibody in vivo. Reverse transcription-PCR showed enhanced suppression of IFN-gamma in Peyer's patch in animals fed MBP and IL-4 versus those fed MBP alone. We then investigated the role of IL-4 in the generation of TGF-beta-secreting cells using MBP Ac1-11 TCR transgenic animals. Cells were cultured with IL-2, IL-4, or IFN-gamma in the presence of MBP and limiting dilution analysis for cytokine-secreting cells performed. We found that IL-4, but not IL-2 or IFN-gamma, generated TGF-beta-secreting T cells from naive splenic T cells and that these cells provided help for IgA production. These findings demonstrate that IL-4 is a differentiation factor for TGF-beta-secreting Th3 cells and oral IL-4 has a synergistic effect on low-dose oral tolerance that is associated with increased TGF-beta secretion.
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PMID:IL-4 is a differentiation factor for transforming growth factor-beta secreting Th3 cells and oral administration of IL-4 enhances oral tolerance in experimental allergic encephalomyelitis. 975 65

A DNA vaccine encoding the immunogenic and biologically active portion of anthrax protective antigen (PA) was constructed. Spleen cells from BALB/c mice immunized intramuscularly with this vaccine were stimulated to secrete IFN gamma and IL-4 when exposed to PA in vitro. Immunized mice also mounted a humoral immune response dominated by IgG1 anti-PA antibody production, the subclass previously shown to confer protection against anthrax toxin. A 1:100 dilution of serum from these animals protected cells in vitro against cytotoxic concentrations of PA. Moreover, 7/8 mice immunized three times with the PA DNA vaccine were protected against lethal challenge with a combination of anthrax protective antigen plus lethal factor.
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PMID:Protection against anthrax toxin by vaccination with a DNA plasmid encoding anthrax protective antigen. 998 72

Accumulating evidence suggests that Th1 T cells play a pivotal role in the development of autoimmune diabetes. Conversely, promoting a Th2 response inhibits disease progression. However, it has not been determined whether Th2 cells are regulatory T cells that fail at the time of diabetes development in naive non-diabetic NOD mice. Therefore, in order to evaluate cytokine secretion by spleen and islet infiltrating T cells in NOD mice at different stages of the autoimmune process, we developed an ELISPOT assay that detects IL-2, IL-4, and interferon-gamma (IFN-gamma) secretion in vitro at the single-cell level. We showed that, whatever the age considered, IFN-gamma is predominantly secreted, and that no IL-4-secreting cells are detected in the islets of male and female NOD mice. Spleen cells from 8-week-old female NOD mice, which include regulatory suppressor T cells, do not secrete IL-4, either upon presentation of islet cell antigens in vitro, or after transfer in vivo, but do secrete IFN-gamma. IFN-gamma secretion by T cells from diabetic mice results from CD4 but not CD8 T cells in transfer experiments into NOD/severe combined immunodeficient (SCID) recipients. These results suggest that (i) detection of regulatory CD4 T cells in NOD mice is not paralleled by a Th2 response; (ii) beta cell destruction does not depend on a switch from a Th2 to a Th1-type response; and (iii) CD8 T cells do not participate in induction of diabetes by secreting IFN-gamma.
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PMID:Absence of significant Th2 response in diabetes-prone non-obese diabetic (NOD) mice. 1033 11

Spleen cells from young and old C57BL/6 mice were stimulated with a combination of anti-CD3 and anti-CD28 antibodies, and the profile of cytokine production was examined by two different methods; the concentrations of cytokines as measured by ELISA, and identification of cytokine-positive cells by flow cytometry. The ELISA method revealed that IL-2 production by spleen cells after stimulation was significantly lower in the old mice compared to the young mice. while IFN-gamma production was the reverse. The flow cytometric analysis showed that the percentage of IL-2 positive cells in spleen cells after the stimulation was significantly lower in the older mice than in the young mice, and vice versa for the percentage of IFN-gamma-positive cells. Regarding the T cell subsets, CD4+ T cells were a major source of IL-2 in both the young and old mice. IL-2-positive cells in both CD4+ and CD8+ T cells showed a significant decrease with age. On the contrary, CDX T cells were the major source of IFN-gamma. An age-related increase of IFN-gamma positive cells was observed in both CD4+ and CD8+ T cells. CD4 T cells were the major source of IL-4, and the percentage of IL-4-positive CD4+ T cells also increased with age, although the level of IL-4 production was modest in C57BL/6 mice compared with IL-2 and IFN-gamma. Such age-related changes of cytokine production are presumed to play an important role in the alteration of immunological capacity with age.
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PMID:Age-related alteration of cytokine production profile by T cell subsets in mice: a flow cytometric study. 1036 89

To determine the significance of interleukin (IL)-10 in antitumor immune response, the effect of the down-regulation of tumor-derived IL-10 on locoregional immunotherapy was investigated. C3H/HeN mice were intraperitoneally (i.p.) inoculated with IL-10-producing murine breast cancer cell line, FM3A, and treated with locoregional administration of OK-432 with or without anti-IL-10 monoclonal antibody (mAb). Anti-IL-10 mAb did not affect the in vitro growth of FM3A cells. Administration of OK-432 plus anti-IL-10 mAb remarkably delayed the retention of malignant ascites and prolonged the survival of mice compared with the administration of OK-432 alone. Spleen cells which were collected from mice treated with OK-432 plus anti-IL-10 mAb and further stimulated in vitro with inactivated FM3A cells exhibited significantly higher cytotoxicity against FM3A cells than those from mice treated with OK-432 alone or from the control mice. The expression of major histocompatibility complex (MHC) class II molecules on spleen cells was up-regulated in vitro by the addition of OK-432 and anti-IL-10 mAb. Using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), cytokine mRNA levels of peritoneal exudate cells (PEC) and spleen cells were assessed on day 7 (before treatment) and day 14 (after treatment). In PEC, increased expression of IL-2 was observed with the administration of OK-432 plus anti-IL-10 mAb. In spleen cells, the expression of IL-2, IL-12 and IFN-gamma were strongly induced, and IL-4 expression was reduced by the administration of OK-432 plus anti-IL-10 mAb. It is suggested that down-regulation of tumor-derived IL-10 induces the up-regulation of the T helper type (Th) 1 population, resulting in an enhancement of the efficacy of locoregional immunotherapy with OK-432.
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PMID:Down-regulation of IL-10 enhances the efficacy of locoregional immunotherapy using OK-432 against malignant effusion. 1036 57

Linomide is a synthetic immunomodulator that has been shown to protect animals against a wide range of spontaneously developing or induced autoimmune diseases. We have previously reported that Linomide blocks both the clinical and the histopathological manifestations of experimental autoimmune encephalomyelitis (EAE) in various animal models. In this study, in an effort to elucidate the mechanisms by which Linomide suppresses EAE, and autoimmunity in general, we investigated the in vivo effects of this drug on the TH1/TH2 lymphocyte balance, which is important for the induction or inhibition of autoireactivity. Naive SJL/J mice were treated orally for 15 days with Linomide (80 mg/kg/day). Spleen cells were obtained at various time points during the treatment period and were stimulated in vitro with concanavalin A. Interleukins IL-4, IL-10 and IL-12, transforming growth factor-beta (TGFbeta) and interferon-gamma (IFNgamma) cytokine production was evaluated both by means of detection of the cytokines in the medium (by ELISA technique) and by detection of the cytokine mRNA production, using a semiquantitative reverse transcriptase polymerase chain reaction method. A significant upregulation of IL-4, IL-10 and TGFbeta was observed following treatment with Linomide, which peaked at day 10 (IL-10) or day 15 (IL-4). On the other hand, IL-12 and IFNgamma production were either unchanged or decreased. It seems therefore that Linomide induces in vivo a shift towards TH2 lymphocytes which may be one of the mechanisms of downregulation of the autoimmune reactivity in EAE. Our observations indicate that downregulation of TH1 cytokines (especially IL-12) and enhancement of TH2 cytokine production may play an important role in the control of T-cell-mediated autoimmunity. These data may contribute to the design of new immunomodulating treatments for a group of autoimmune diseases.
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PMID:Linomide downregulates autoimmunity through induction of TH2 cytokine production by lymphocytes. 1036 27

Along humoral immune responses, different stimuli drive the differentiation of B lymphocytes to Ig-secreting plasma cells in discrete microenvironments. The Blimp-1 transcription factor is up-regulated early during the transition of mature B cells to IgM-secreting plasma cells. In the present study, we have examined the requirement of Blimp-1 in plasma cell formation after both T cell-independent (LPS) and -dependent (CD40 + IL-4, Th cell lines) stimulation of spleen B cells. B lymphocyte-induced maturation protein (Blimp-1) was expressed early after in vitro LPS stimulation, mainly in a population of IgM+Syndecan+CD43+ preplasma cells. In contrast, the BSAP transcription factor expressed in mature B cells was down-regulated during the differentiation to plasma cells. Treatment of these cultures with Blimp-1-specific antisense phosphorothioate oligonucleotides suppressed both Blimp-1 protein levels and the emergence of IgM+Syndecan+ cells and plasma cells. However, T-B cell cocultures of spleen B cells from C3H/HeJ (H-2k) mice and syngeneic autoreactive SR.10 Th2 cells submitted to the anti-Blimp-1 therapy did not show any significant reduction in IgM- and IgG1-secreting plasma cell formation. Spleen B cells treated with anti-CD40 mAb + IL-4 differentiated to IgG1-secreting cells without significant transcription of the Blimp-1 gene; anti-Blimp-1 treatment subsequently did not have any effect in the later cultures. Altogether, these results suggest that Blimp-1 transcription factor specifically promotes T cell-independent B cell differentiation to plasma cells, probably at preplasma cell stages. In contrast, T cell-dependent plasma cell formation likely evolves through Blimp-1-independent pathways.
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PMID:Differential involvement of the transcription factor Blimp-1 in T cell-independent and -dependent B cell differentiation to plasma cells. 1039 48

In some parasitic infections immunosuppression is a prominent characteristic of the host-parasite interplay. We have used a murine alveolar echinococcosis (AE) model in susceptible C57BL/6 mice to document a suppressed splenocyte proliferative response to concanavalin A (Con A) at the early (1-month) stage and to Echinococcus multilocularis-crude antigen (Emc-antigen) at the late (4-6-month) stage of chronic infection. Despite proliferative suppression, splenic cytokine production [interleukin-2 (IL-2), IL-4 and interferon-gamma (IFN-gamma)] in response to Con A or Emc-antigen stimulation was not suppressed at 1 month postinfection (p.i.). Infection resulted in a strong Mac-1+ cell infiltration of the peritoneal cavity and spleen. Peritoneal cells (PEC) from mice infected at the 1-month stage were rich in macrophages and expressed significantly higher levels of transcripts for the inflammatory cytokine IL-1beta and for tumour necrosis factor-alpha and inducible nitric oxide synthase (iNOS), when compared with PEC from non-infected control mice. Conversely, the IL-10 transcript level remained low and did not change during infection. Spleen cells supplemented with PEC from infected mice induced a marked increase in the levels of nitrite in response to Con A and Emc-antigen stimulation, and also a complete suppression of splenic proliferation. The spleen cells from late-stage infected mice expressed only background levels of IL-10 but greatly increased levels of iNOS, when compared with normal spleen cells. This observation correlated with the immunosuppression demonstrated at the late stage of murine AE. Furthermore, the suppressed splenic proliferative responses observed at the early and late stage were reversed to a large extent by the addition of NG-monomethyl-l-arginine and partially by anti-IFN-gamma. Thus, our results demonstrated that the immunosuppression observed in chronic AE was not primarily dependent on IL-10 but rather on nitric oxide production by macrophages from infected animals.
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PMID:Nitric oxide-mediated immunosuppression following murine Echinococcus multilocularis infection. 1044 21

Two RESA repeat sequences, (EENVEHDA)2 and (DDEHVEEPTVA)2, were chemically linked to a universal T-cell epitope, CS.T3 and polytuftsin, and a natural immunopotentiator, was physically mixed with these conjugates. The immunogens were studied for in vitro antigen-induced T-cell proliferation, and cytokine levels were measured in the culture supernatants. The RESA peptide(s)-CS.T3 conjugate containing polytuftsin showed the highest stimulation index (SI) as compared to the RESA peptide-CS.T3 conjugates or RESA peptides alone. Spleen cells from mice primed with either RESA peptide(s)-CS.T3 conjugate or RESA peptide-CS.T3 conjugate containing polytuftsin, when pulsed in vitro with the respective RESA peptide, showed a higher proliferation index as compared to spleen cells primed and pulsed in vitro with the respective RESA peptides. This observation has an important relevance during natural reinfection for boosting the immune response. The culture supernatants from the cells primed and pulsed in vitro with RESA peptide-CS.T3 conjugate and RESA peptide-CS.T3 conjugate containing polytuftsin showed higher IL-2 and IFN-gamma levels as compared to the RESA peptides alone. Very low IL-4 levels were detected with the above formulations. The cytokine profile is suggestive of a CD4+ TH1 type of immune response, which is ideal for the killing of intracellular pathogens like the malarial parasite.
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PMID:Correlation of T-cell response and lymphokine profile with RESA peptides of Plasmodium falciparum containing a universal T-cell epitope and an immunopotentiator, polytuftsin. 1048 May 52

The expression of cytokines may influence the development of lymphoma in retrovirally infected animals in at least two ways: (1) cytokines in the tumor environment may stimulate the proliferation of tumor cells and/or (2) cytokines in the tumor environment may diminish the cell-mediated antitumor immune response. To evaluate these possibilities, a semiquantitative RT-PCR approach was utilized to permit a broad screening of cytokine mRNAs in a large number of tissue samples. Examination of MuLV-induced end-stage lymphomas revealed the absence of mRNA for cytokines known to stimulate the proliferation of T cells (i.e., IL-2, IL-9), the absence of mRNA for cytokines known to enhance cell-mediated antitumor immune responses (i.e., IL-2, IFNgamma), and the presence of mRNA for cytokines known to diminish such responses (i.e., IL-4, IL-10). Similar patterns of cytokine mRNA expression were detected in tumor-derived cell lines. Spleen and thymus from animals collected longitudinally during infection and from age-matched uninfected mice also demonstrated a similar pattern, except that IFNgamma mRNA was readily detectable. These findings do not support the hypothesis that the developing tumor depends on cytokines to provide proliferative signals. The findings suggest that cytokines in the immediate environment of the lymphoma support tumor development by acting to diminish an effective antitumor immune response.
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PMID:High levels of IL-4 and IL-10 mRNA and low levels of IL-2, IL-9 and IFN-gamma mRNA in MuLV-induced lymphomas. 1049 10


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