Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated whether gamma interferon (IFN-gamma; a Th1 cytokine), tumor necrosis factor alpha (TNF-alpha), and interleukin-4 (IL-4; a Th2 cytokine) modulate nitric oxide (NO) production in vivo during blood stage infection with Plasmodium chabaudi AS. Treatment of resistant C57BL/6 mice, which resolve infection with P. chabaudi AS and produce increased levels of IFN-gamma, TNF-alpha, and NO early during infection, with anti-IFN- gamma plus anti-TNF-alpha monoclonal antibodies (MAbs) resulted in a reduction of both splenic inducible NO synthase mRNA and serum NO3- levels by 50 and 100%, respectively. Treatment with the anti-TNF-alpha MAb alone reduced only serum NO3- levels by 35%, and treatment with the anti-IFN-gamma MAb alone had no effect on NO production by these mice during infection. Susceptible A/J mice, which succumb to infection with P. chabaudi AS and produce increased levels of IL-4 but low levels of IFN-gamma, TNF-alpha, and NO early during infection, were treated with an anti-IL-4 MAb. The latter treatment had no effect on NO production by this mouse strain during infection. In addition, our results also demonstrate that treatment of resistant C57BL/6 mice with anti-IFN-gamma plus anti-TNF-alpha MAbs affects, in addition to NO production, other traits of resistance to P. chabaudi AS malaria such as the peak level of parasitemia and the development of splenomegaly. Furthermore, the change in spleen weight was shown to be an IFN-gamma-independent effect of TNF-alpha. Treatment of susceptible A/J mice during infection with an anti IL-4 MAb had no effect on these markers of resistance. Thus, these results demonstrate that TNF-alpha and IFN-gamma are critical in the regulation of NO production and other traits of resistance during P. chabaudi AS malaria in C57BL/6 mice. These data also indicate that treatment with an anti-IL-4 antibody alone is not able to induce NO production or confer resistance to A/J mice against P. chabaudi AS malaria.
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PMID:In vivo regulation of nitric oxide production by tumor necrosis factor alpha and gamma interferon, but not by interleukin-4, during blood stage malaria in mice. 855 72

Administration of Interferon-gamma (IFN gamma) is used in the therapeutic approach for mainly cancer treatment and viral infections in vivo. Recently we observed some important pathologic dysfunctions caused by IFN-gamma administration to pregnant mice. This treatment affected not only the growth and development of the feto-placental unit, but also, among other hematologic disorders, caused splenomegaly to the mother. In an effort to explain the observed hypersplenism, we have analysed the behaviour of macrophages, B and T lymphocytes in the spleen of virgin and pregnant mice after intraperitoneal administration of low IFN-gamma doses. Although the percentage of myeloid Mac-1 and F4/80 positive cells in spleen cell suspensions of virgin and pregnant mice do not change with the IFN-gamma treatment, immunoperoxidase staining of frozen spleen sections shows that in pregnant mice the monocytic cells accumulate at the central white pulp area of the organ, whereas in non-pregnant mice these cells are mainly found at the peripheral red pulp area. In contrast, the same treatment was shown to increase the numbers of Ly5 positive B cells in both virgin and pregnant mice, whereas B cells were found to form clusters only in the case of pregnant animals. We also show that IFN-gamma increases the numbers of Tcyt/sup (Ly2 positive cells) and TH (L3T4 positive cells) in the spleen of virgin mice but not in pregnant mice. Both populations display a physiologic distribution in the white pulp of the organ as assessed by immunoperoxidase staining of frozen spleen sections. Interestingly, the distribution pattern of IL-2- and IL-4-producing cells, which reflects the presence of Th1 and Th2 subpopulations was different in pregnant and virgin mice. Gestating females had IL-2 producing cells dispersed in the white pulp area, whereas IL-4 producing cells formed clusters mainly at the periphery of the organ. Virgin females had almost undetectable levels of IL-4 producing cells, whereas IL-2 producing cells were found at the periphery. Our results indicate that IFN-gamma alters the equilibrium between Th1 and Th2 cells, which in turn is responsible for the redistribution of myeloid and lymphoid cells in the spleen of pregnant mice thereby explaining the development of an active immune/inflammatory reaction.
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PMID:Effect of IFN-gamma administration in virgin and pregnant mice: distribution of lymphoid and myeloid cells in the spleen. 858 73

Because IL-12 restores allogeneic cytotoxic T lymphocyte (CTL) activity by T cells of aged mice in vitro, we initially assessed whether IL-12 could overcome age-related deficits when given to aged mice in vivo. Growth of P815(H-2(d)) was enhanced in aged compared with young BALB/c (H-2(d)) mice and tumor growth was curtailed by IL-12 in both age groups. Unexpectedly, secondary CTL stimulated ex vivo with P815 were reduced in IL-12-treated mice compared with controls. Primary CTL generated ex vivo across MHC differences in IL-12 treated BALB/c and C57BL/6 young mice were reduced by 90-99%, were dose- and time-dependent, and were associated with reduced allo-stimulated NK-like activity and [3H]thymidine incorporation. IFN-gamma was elevated in sera and in supernatants from allo-stimulated cultures from IL-12-treated mice, while IL-4 was reduced in such supernatants, suggesting that, despite reduced CTL, IL-12 was associated with increased Th1- and reduced Th2-type cytokine production. IL-12 also induced splenomegaly, primarily due to increased numbers of cells lacking markers of mature T, B and NK cells, or macrophages, or polymorphonuclear leukocyte morphology. IFN-gamma mutant mice exhibited reduced splenic enlargement in response to IL-12, suggesting that the splenomegaly was due, in part, to IFN-gamma production. However, reduced CTL generation was not due entirely to dilution of CTL precursor cells because spleen cellularity and size increased 3-fold while CTL activity decreased 10- to 100-fold, and CTL generation normalized to CD8(+) T effector cells was still significantly reduced in IL-12-treated mice. Interestingly, purified CD4(+) and CD8(+) T cells from IL-12-treated normal mice exhibited greater proliferative and cytolytic activities respectively compared with controls. Thus, effector T cells in IL-12-treated mice were not impaired, but exhibited augmented responsiveness, suggesting that IL-12 induced complex interactions among spleen cell populations and that these effects, in part, are mediated by IFN-gamma.
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PMID:IL-12 administered in vivo to young and aged mice. Discrepancy between the effects on tumor growth in vivo and cytotoxic T lymphocyte generation ex vivo: dependence on IFN-gamma. 867 53

Both interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-alpha) are produced early in intracellular bacterial infection. Depletion of either IL-12 or TNF-alpha by a single injection of specific antibody 4 h before the injection of Brucella abortus 19 led to the exacerbation of infection 2 weeks later. Whereas the effect of IL-12 depletion on resistance was persistent and exacerbation was still significant 6 weeks later, the bacterial numbers in mice depleted of TNF-alpha were similar to the bacterial numbers in control infected mice by 6 weeks postinfection. Massive splenomegaly, which is often seen in 2-week Brucella-infected mice, was not observed in IL-12- or TNF-alpha-depleted mice. Both IL-12- and TNF-alpha-depleted mice showed reduced cell accumulation in the spleen compared with the massive cell accumulation in control infected mice. Granuloma formation in livers was much reduced in IL-12-depleted mice but not in TNF-alpha-depleted mice. Gamma interferon (IFN-gamma) production by cells from TNF-alpha-depleted mice was not significantly different from that of cells from control infected mice. In contrast, the production of IFN-gamma by both CD4+ and CD8+ T cells from IL-12-depleted mice was greatly reduced, compared with that from control infected mice. This effect was still observed when the antibody injection was delayed for up to 7 days postinfection, but injections of anti-IL-12 antibody into mice with established Brucella infection had no significant effect on IFN-gamma production by T cells. Taken together, these results suggested that IL-12 contributed to resistance mainly via an IFN-gamma-dependent pathway and had a profound effect on the induction of acquired cellular resistance. In contrast, TNF-alpha was involved in resistance possibly via direct action on effector cells and may not be essential for the induction of acquired cellular resistance.
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PMID:Tumor necrosis factor alpha and interleukin-12 contribute to resistance to the intracellular bacterium Brucella abortus by different mechanisms. 869 8

Interleukin (IL-12) protein has been shown to elicit diverse immunological responses and potent antitumor activity. We demonstrate here that intradermal injection of IL-12 cDNA induces systemic biological effects characteristic of the cytokine in vivo. Intradermal injection of IL-12 cDNA resulted in local expression of IL-12 mRNA, which correlated with a 10-fold increase in natural killer activity and a 3-4-fold increase in anti-CD3-induced IFN-gamma production in cultured splenocytes. Furthermore, when challenged with Renca tumor cells at a distant site, the day of tumor emergence was significantly delayed, and tumor growth was reduced in mice that received IL-12 cDNA, compared to mice given injections of plasmid vector alone. A number of the mice receiving IL-12 cDNA injections remained tumor free months after tumor challenge. In contrast to mice receiving recombinant IL-12 protein, no splenomegaly was detected when natural killer activity was significantly induced in mice receiving injections of IL-12 cDNA. Because purified plasmid DNA is more economical to prepare and has a longer shelf-life than recombinant proteins, and intradermal administration of cDNA encoding IL-12 did not cause splenomegaly, our findings suggest that the in vivo injection of cDNA encoding IL-12 may be a less toxic and more cost-effective alternative to IL-12 protein therapy in some clinical or experimental therapeutic applications.
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PMID:Injection of complementary DNA encoding interleukin-12 inhibits tumor establishment at a distant site in a murine renal carcinoma model. 875 1

The immune status of BALB/c mice infected by intraperitoneal inoculation with Ehrlichia muris was examined. The level of E. muris infection in both peritoneal cavity and spleen was greatest at day 10 postinoculation (PI). Thereafter, the infection level was dramatically reduced while the organism persisted for up to 400 days PI. The greatest intraperitoneal infiltration of leukocytes, splenomegaly, and leukocytosis were observed on days 10, 15, and 20 PI, respectively. Infected mice developed marked hypergammaglobulinemia of IgG and IgM that peaked at day 20 PI; however, IgA plummeted at day 15 PI. Of IgG, G2a and G3 increased while G1 and G2b remained constant. Despite hypergammaglobulinemia, both IgG and IgM antibody titers against E. muris were very low throughout the 30-day study. Antibody development and plaque-forming cells against sheep red blood cells (SRBC) were abolished when the antigen was inoculated on day 10 PI. IgM antibody development against SRBC was more severely inhibited than IgG antibody development. However, when mice were immunized with SRBC prior to E. muris infection, antibody development against SRBC was not reduced. Delayed type hypersensitivity reaction to dinitrofluorobenzene was also maximally inhibited when the antigen was administered on day 10 PI. The IFN-gamma level in the blood was maximal at day 10 PI. These results indicate that although the vigorous polyclonal activation and protective IFN-gamma responses occurred by day 10 PI- which cleared most of the ehrlichial infection-antigen-specific immune stimulation was impaired primarily at the level of antigen-priming at peak parasitemia.
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PMID:Impaired antigen specific responses and enhanced polyclonal stimulation in mice infected with Ehrlichia muris. 888 52

Inbred CBA/J mice with chronic (20-week) Schistosoma mansoni infections demonstrate two distinct syndromes. Hypersplenomegaly syndrome (HSS), characterized by a massive spleen, liver fibrosis, ascites, and anemia, resembles hepatosplenic human schistosomiasis, complete with portal hypertension and shunting. Moderate splenomegaly (MSS) syndrome, with less severe pathology, parallels most chronic human infections. Phenotypic analyses of spleen cells for CD44, CD62L, CD45RB, Ia, and CD25 indicate that HSS mice have more activated and memory CD4+ T cells than do MSS mice. HSS animals also have more B cells that highly express B7-2. Anti-CD3 stimulated spleen cells from 8-week or chronically infected mice produce IL-4 and IL-10 in a manner that appears not to involve the CD28/B7-2 costimulation pathway. By contrast IFN-gamma production is augmented in the presence of anti-CD28 and decreased in the presence of anti-B7-2. Infected mice make very little IL-2 to anti-CD3, even with added anti-CD28. As cytokines affect resultant B-cell responses and HSS and MSS mice display distinctive isotypes, differential regulatory or anergy hypotheses may best explain MSS/HSS differences.
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PMID:Immunopathogenesis and immunoregulation in schistosomiasis. Distinct chronic pathologic syndromes in CBA/J mice. 899 59

Inbred male CBA/J mice with chronic Schistosoma mansoni infections develop two distinct syndromes. Hypersplenomegaly syndrome (HSS) demonstrates pathologic similarities to the hepatosplenic form of chronic human schistosomiasis, and moderate splenomegaly syndrome (MSS) resembles the asymptomatic intestinal form. Immunoaffinity-purified Abs against S. mansoni soluble egg Ags (SEA) from infected patients' sera differ idiotypically according to the donor's clinical form of the disease. We now show that immunoaffinity-purified anti-SEA Abs (Id) from MSS or HSS mice parallel idiotypic preparations of the analogous human clinical form by their differential ability to stimulate the proliferation of anti-Id T cells. MSS Id preparations stimulate spleen cells from either MSS or HSS animals. In contrast, HSS Id does not stimulate spleen cells from either group. In an anti-SEA ELISA, MSS and HSS Id preparations contained comparable levels of IgM and IgG1. However, the MSS Id preparation had higher levels of SEA-specific IgG2a and IgG2b than did HSS Id. The Ig isotypes of these Id preparations suggested differences in cytokine expression patterns. Studies of the cytokine profiles of the spleen cells responding to anti-SEA Id preparations demonstrated that while Id preparations from acutely infected mice stimulate IL-4 and IL-10 production, Id preparations from chronic MSS mice stimulate IFN-gamma production. HSS Id did not stimulate the production of any of these cytokines. The possibility that distinct immunoregulatory environments may contribute to the development of MSS and HSS correlates with earlier hypotheses that hepatosplenic pathology results at least in part from a lack of development or expression of appropriate regulatory Ids.
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PMID:Immunoregulatory idiotypes stimulate T helper 1 cytokine responses in experimental Schistosoma mansoni infections. 910 46

To investigate the role of cell-mediated immunity in the control of Mycobacterium avium infection, we studied the effects of targeted gene disruptions in components of the T lymphocyte-dependent, macrophage-mediated response on resistance of mice to this pathogen. Normal mice developed a chronic, asymptomatic infection, with rapid induction of mRNAs for IFN-gamma, IL-12, and TNF-alpha in spleen, liver, and lung. Bacterial loads in gene knockout, scid, and wild-type mice were indistinguishable for the first 4 wk of infection. However, by 8 wk postinfection, scid mice as well as animals with a targeted disruption of the IFN-gamma gene showed enhanced bacterial growth compared with wild-type controls. In contrast, knockout mice lacking the genes for the TNF-alpha p55/p75 receptors or inducible nitric oxide synthase not only developed comparable bacterial loads to wild-type animals, they also failed to display the splenomegaly and profound suppression of mitogen-induced lymphocyte proliferative responses evident in infected wild-type controls. Thus, M. avium is clearly distinct from other intracellular pathogens (e.g., Leishmania monocytogenes, Toxoplasma gondii, and Mycobacterium tuberculosis) whose initial replication in the host is tightly controlled by Th1-dependent effector mechanisms. Instead, the major effect of host cell-mediated immunity is to limit bacterial growth during the chronic phase of infection. Surprisingly, inducible nitric oxide appears to be more important for the immunopathology than for the host resistance induced by this bacterial pathogen.
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PMID:Defects in cell-mediated immunity affect chronic, but not innate, resistance of mice to Mycobacterium avium infection. 914 97

Mice with a targeted disruption of the Rel/nuclear factor-kappaB family member RelB develop a complex inflammatory phenotype, myeloid hyperplasia, and splenomegaly due to extramedullary hemopoiesis. In this work, we report that RelB-deficient mice, in addition to the pathologic changes, were highly susceptible to infection by the facultative intracellular bacterium Listeria monocytogenes. RelB binds transcriptionally active kappaB motifs in the TNF-alpha promoter in normal cells, and in vitro studies with macrophages isolated from RelB-deficient animals revealed impaired production of TNF-alpha in response to LPS and IFN-gamma. RelB-deficient mice also were unable to mount a protective immune response against lymphocytic choriomeningitis virus. These results indicate a defective T cell-macrophage interaction and cytotoxic T cell response, respectively, in mice lacking RelB. Analysis of resting and specific Ab production demonstrated that while RelB is not required for the secretion of Ig isotypes that result from heavy chain class switching, it is necessary for normal production of Ag-specific IgG in response to T cell-dependent and -independent stimuli. Thus, RelB is not only essential for a normal hemopoietic system in the unchallenged animal, but also involved in various specific and nonspecific immune responses.
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PMID:Multifocal defects in immune responses in RelB-deficient mice. 916 38


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