Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Injection of syngeneic lymphoma cells in AKR mice, resulted in an important increase of splenic natural killer (NK) activity in the early days following the graft. Modifications of the production of different types of cytokine: interferon, interleukins 1 and 2, tumor necrosis factor (IFN, IL-1, IL-2, TNF), involved in the regulation of NK activity, were investigated in short-term cultures of total, adherent and non-adherent fractionated spleen cells, using lipopolysaccharide as the triggering or amplifying agent. Upon stimulation with lipopolysaccharide, splenocytes from lymphoma-grafted mice released a large amount of interferon as compared to controls with a maximum level 1 day after the graft. Equal amounts of IFN-gamma and IFN-alpha/beta were detected. Treatment of spleen cells prior to culture with anti-(asialo-GM1) or anti-(Thy-1.1) antibodies reduced interferon production by 80% and 50% respectively. This finding indicates that (a) the IFN-gamma is produced by Thy-1-positive cells and (b) the production of IFN-gamma by these cells is at least partially under the control of asialo-GM1-positive cells. We also showed that non-adherent fractionated spleen cells from lymphoma-grafted mice produced IL-1 and IL-2. IL-1 was released by asialo-GM1-positive cells and IL-2 by Thy-1-positive cells. Adherent cells released only IL-1. In contrast, total cells released smaller amounts of IL-1 and IL-2, suggesting a reciprocal inhibition between subpopulations of non-adherent and adherent cells. A high level of TNF production by adherent cells was observed only 4 days after the graft. These results indicate that graft of lymphoma cells entails important modifications of spleen cell populations releasing different types of cytokines implicated in NK activation.
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PMID:Production of cytokines after lipopolysaccharide stimulation of murine spleen cells during lymphoma development in AKR mice. 246 13

The gamma interferon (IFN-gamma) production and the cell populations participating to this production were examined in Toxoplasma-infected mice. When spleen cells from Toxoplasma-infected mice were cultured with Concanavalin A (Con A) or OK-432, a Streptococcal preparation, they produced significantly high levels of IFN-gamma as compared with that of noninfected mice. Such enhanced IFN titers were observed as early as at 5 days postinfection, reached at the maximum levels on 20 days around and declined gradually thereafter. Treatment of spleen cells from the infected mice with either monoclonal anti-Thy-1.2 antibody plus complement or macrophage-blocking agents virtually abolished the IFN production. The spleen cells producing IFN-gamma were more susceptible to the treatment with monoclonal anti-Lyt-1.2 than anti-Lyt-2.2 antibodies, suggesting that CD4+ T cells are main producers of this lymphokine. When mice infected with Toxoplasma 10 days previously were injected with lipopolysaccharide (LPS), a well-known inducer of IFN-alpha/beta, the sequential production of IFN-alpha/beta and IFN-gamma was induced in their circulation.
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PMID:Augmented production of gamma interferon in mice experimentally infected with Toxoplasma gondii. 250 May 52

When spleen cells of C57BL/6 mice or mast cell-deficient W/Wv mice were cultured, their histidine decarboxylase (HDC) activity increased with increases in the histamine concentration in the cells and the medium. Addition of concanavalin A (Con A) or Escherichia coli lipopolysaccharide (LPS) enhanced the increase. The removal of adherent cells reduced both the control HDC activity and the response to the mitogens. Purified T lymphocytes responded to Con A but not to LPS. Neither Con A nor LPS had any effect on B lymphocytes. Treatment of T cells with anti-Thy-1.2 and complement completely abrogated the induction of HDC. Histamine synthesis dependent on Con A by T cells was stimulated by the addition of conditioned medium from peritoneal adherent cells activated with LPS. The addition of recombinant interleukin-1 (rIL-1) or peritoneal adherent cells fixed with paraformaldehyde significantly enhanced HDC induction dependent on Con A in T cells. These results suggest that histamine is synthesized by T lymphocytes through HDC and that the reaction was enhanced by a soluble factor(s) released from macrophages.
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PMID:Histamine synthesis by mouse T lymphocytes through induced histidine decarboxylase. 278 10

AKR/Gross leukemia virus-induced tumor reactive cytotoxic T lymphocyte (CTL) clones were derived from C57BL/6 spleen cells. Analysis of their specificity pattern was performed by using a panel of target cells such as E male G2 and AKR.H-2bSL1 (susceptible tumors to polyclonal anti-AKR/Gross virus CTL), and cl. 18-5 and cl. 18-12 (insusceptible variant sublines derived from AKR.H-2bSL1). Several of these CTL clones were selected for further study. Lysis of Gross cell surface antigen-positive tumor cells by these clones was restricted by the H-2Kb molecule. The cell surface phenotype of these clones was Thy-1.2+, Lyt-2.2+, L3T4-, a phenotype consistent with that of polyclonal anti-AKR/Gross CTL, suggesting that they were of conventional CTL origin. According to their fine specificity pattern, the CTL clones were divided into two major groups (A and B) which were further subdivided into five and three subgroups, respectively. The specificity of group A clones was essentially the same as that of the standard polyclonal CTL population except for a variable level of natural killer-like activity by some of the CTL clones. That is, group A clones did not efficiently lyse the insusceptible variant tumors nor any of Friend-Moloney-Rauscher-positive tumors tested, but they showed strong lytic activity to susceptible tumors and iododeoxyuridine-treated insusceptible variants. Thus, their CTL activity appeared to be strictly directed to Gross cell surface antigen-positive tumors that are susceptible to polyclonal anti-AKR/Gross virus CTL. In contrast, group B clones could lyse both susceptible and insusceptible variant tumors and also a Friend virus-induced tumor (FBL3). Therefore, as defined by these CTL clones, at least two distinct antigenic systems (A and B), each with several antigenic determinants, appeared to be present. Because recent findings suggested that most of the polyclonal anti-AKR/Gross virus CTL activity appeared to be directed to N-ecotropic proviral determinants, we further investigated the nature of these two antigenic systems by use of additional target cells including lipopolysaccharide (LPS)-stimulated spleen cell blasts from AKXL recombinant inbred strains and retrovirus-infected fibroblasts. Group A clones could lyse all LPS blasts derived from AKXL recombinant inbred strains containing the AKV-1 proviral genome, but lysed only very insufficiently or did not lyse AKV-1-negative blasts containing the AKV-3 and/or AKV-4 provirus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Clonal heterogeneity of anti-AKR/gross leukemia virus cytotoxic T lymphocytes. Evidence for two distinct antigen systems. 282 Nov 16

Bacterial lipopolysaccharide (LPS) induced fresh murine splenocytes to produce interferon (IFN)-alpha/beta presumably by stimulation of the B lymphocytes and macrophages. However, when the splenocytes were "aged" for 24 to 72 hr in culture before addition of the LPS, the IFN response was significantly increased and was determined to be predominantly IFN-gamma. Because low levels of interleukin 2 (IL 2) were found to be spontaneously produced by the unstimulated splenocytes during the "aging" process, the effect of IL 2 on IFN induction by LPS in fresh splenocytes was examined. The addition of LPS to freshly prepared splenocyte cultures that were treated with human IL 2, either native or recombinant, before exposure to the LPS resulted in the LPS inducing large amounts of IFN-gamma. IL 2 alone induced little if any IFN in the splenocyte cultures. Depletion of T cells and large granular lymphocytes (LGL) from the cultures by anti-Thy-1.2 antibodies plus complement abrogated IFN-gamma production, and the addition of polymyxin B to "aged" splenocyte cultures resulted in loss of IFN production in response to LPS. Cultures that were enriched for T cells and LGL by passage through nylon wool produced significant amounts of IFN-gamma in response to LPS only if first treated with IL 2. Furthermore, the addition of splenic adherent cells to purified nylon wool-non-adherent (NWNA) cells augmented IFN-gamma production, whether or not the NWNA cells were pretreated with IL 2. This enhancement appeared to require direct contact between adherent cells and NWNA cells, because physical separation abrogated IFN production. The addition of recombinant IL 1 or LPS-conditioned supernatants of macrophage cultures did not replace adherent cell activity. These data demonstrate that LPS, which predominantly induces IFN-alpha/beta in fresh murine splenocytes, is able to stimulate T lymphocytes to produce IFN-gamma if the T cells are first exposed to endogenously produced or exogenously applied IL 2. Because IFN-gamma is a potent activator of the bactericidal and cytocidal potential of macrophages, the induction of IFN-gamma by bacterial LPS may play an important role in resistance/recovery mechanisms against bacterial infections.
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PMID:Interferon-gamma induction by lipopolysaccharide: dependence on interleukin 2 and macrophages. 286 14

By pre-activation with a monoclonal anti-IgM antibody coupled to Sepharose, either in the absence or presence of low doses of lipopolysaccharide, mouse B cell populations were rendered responsive to recombinant DNA derived human interleukin 2 (IL 2). However, if the B cell populations were subjected to separation based on their buoyant density before pre-activation, only low but not high buoyant density cells became responsive to IL 2. Both cell populations subsequent to anti-IgM pre-activation were equally responsive to a Sephadex G-100 fraction of supernatants from rat spleen cells stimulated with concanavalin A. Furthermore, the differences in the IL 2 titration curves on T and B cell populations indicate that only a subpopulation of cells are responding to IL 2 in the B cell populations. In B cell populations that did respond to IL 2, a population of Thy-1.2-positive cells appeared. The proportion of IL 2-responsive T cells needed to give a significant signal when admixed with nonresponding B cell populations was quantitated to be less than 1%.
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PMID:Mouse B cells do not proliferate in human interleukin 2. 286 54

Thy-1, a cell-surface glycoprotein of undetermined function, is expressed in relatively large amounts on mouse thymocytes, peripheral T cells, and neurons. It is widely used as a marker to distinguish peripheral T cells from B cells in mice. We show here that, in five distinct mouse strains, recombinant interleukin 4 (IL-4/B-cell stimulatory factor 1) strikingly induces membrane expression of Thy-1 on the vast majority of lipopolysaccharide (LPS)-stimulated normal murine B cells. Thy-1+ B cells are precursors for immunoglobulin-secreting cells. RNA blot analysis indicates that B cells express a Thy-1 mRNA of 1.8 kilobases, the same size as that found in T cells. Cell mixing experiments show that only cells derived from Thy-1.2+ donors express Thy-1.2, indicating that B cells expressing Thy-1 have not passively absorbed the glycoprotein from another cell source. Recombinant interferon-gamma inhibits Thy-1 induction by B cells stimulated with LPS and IL-4. Thy-1 is also induced on B cells that have been stimulated as a result of the specific activation of an IL-4-producing T-helper clone. Anti-IL-4 monoclonal antibody inhibits the induction of B-cell Thy-1 in this T-cell-B-cell interaction.
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PMID:Interleukin 4 induces membrane Thy-1 expression on normal murine B cells. 290 Oct 96

We previously described that natural autocytolytic cells (NACs) which were detected in the mesenteric lymph nodes (MLNs) of normal mice, did lyse leukocytes contained in the same lymph nodes. Discrete plaques were observed in monolayers of leukocytes prepared in wells of a microculture plate by NACs phagocytizing and lysing other leukocytes. A large NAC which was morphologically similar to macrophage was found in the middle of each plaque. The mechanisms of autocytolysis by NACs were further investigated in the present study. In contrast to various types of autocytotoxic cells reported previously, for which the incubation with fetal calf serum (FCS) was a prerequisite, the NACs showed their cytolytic activity even in serum-free medium. This excluded the possible "sensitization" by FCS proteins in vitro. The presence of the phagocytosis inhibitor cytochalasin B eliminated the autocytolysis. The peroxide scavenger thioglycollate broth had no effect on the formation of autocytolytic plaques. These results further support the previous finding that autocytolytic plaques were formed by NACs phagocytizing other leukocytes. Autologous nonadherent spleen cells and erythrocytes were also phagocytized by MLN-NACs with plastic adherent characteristics. Ia antigen was demonstrated on the surface of an approximately half population of NACs but neither Thy-1.2 antigen nor immunoglobulins. NACs may represent a subpopulation of macrophages, although the majority of adherent, phagocytic macrophages did not show the NAC activity. The endotoxin lipopolysaccharide (LPS) of Escherichia coli was apparently able to activate MLN-NACs of BALB/c mice in vivo when injected intraperitoneally at a dose of 10 micrograms/ml. A peak of the NAC activity was observed 3 days after the injection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Activation of murine natural autocytolytic cells which phagocytize normal autologous leukocytes. 296 Jul 91

Reconstitution of lethally irradiated mice with spleen cells from donors that had been treated with lipopolysaccharide (LPS) intravenously and allogeneic spleen cells subcutaneously leads to a suppressed anti-host delayed-type hypersensitivity (DTH). Either donor injection alone proved to be ineffective. The state of suppression appeared to be antigen-specific, but, depending on the experimental conditions, also anti-host DTH to third-party alloantigens could be suppressed. The suppression was mediated by a population of Thy-1- suppressor cells that could also be induced in athymic nude mice. The suppressor cells specifically adhered to anti-kappa-coated plastic plates, but were not adsorbed by passage through a Sephadex G-10 column. Thus, it appears that the combined donor treatment with LPS and allogeneic spleen cells induces a population of B cells that can suppress anti-host immune reactivity.
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PMID:Lipopolysaccharide-induced suppression of graft-versus-host reactivity in mice. 297 15

T cells from murine lupus strains manifest complex defects in interleukin 2 (IL 2) production and receptor expression. The capacity of B cells from such mice to utilize IL 2 as a growth factor has not been previously reported and is examined herein. Anti-Thy-1.2 plus complement-treated spleen cells from 6-8-week-old autoimmune MRL-lpr/lpr mice and from age and sex-matched immunologically normal CBA/J mice were cultured with lipopolysaccharide (LPS) for 36 h and analyzed for the expression of IL 2 receptors using the monoclonal antibody 7D4. The percentage of B cells expressing IL 2 receptors was comparable in MRL-lpr/lpr and CBA/J mice. In contrast to those from CBA/J, BALB/c and (BALB/c X NZW)F1 mice, LPS-stimulated B cells from MRL-lpr/lpr and from (NZB X NZW)F1 mice were capable of proliferating in response to IL 2. Fractionation of MRL-lpr/lpr B cells using Percoll gradient density separation demonstrated that the IL 2-responsive population consisted predominantly of large cells. In addition, unfractionated B cells from MRL-lpr/lpr mice were found to be substantially more responsive to IL 2 than those from CBA/J and BALB/c mice following activation with anti-immunoglobulin plus LPS. The hyper-responsiveness to IL 2 may be a consequence of the state of activation of autoimmune B cells and is of potential importance in the pathogenesis of systemic lupus erythematosus.
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PMID:Interleukin 2 is a proliferative signal for B cells from autoimmune mice. 309 46


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