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)

Spleen cells from uninfected control mice selectively lysed BALB/c 3T3 fibroblasts infected with mouse hepatitis virus (MHV), a murine coronavirus. Lysis of infected cells occurred within 3 hr, and histocompatibility between effector and target cells was not required. This natural, cell-mediated, virus-associated cytotoxicity differed from NK cell- and T cell-mediated lysis. Spleen cells from animals infected with MHV were enriched in NK activity and were more cytotoxic to YAC-1 target cells, but did not show enhanced cytotoxicity for MHV-infected target cells. Spleen cells from beige mice, which are deficient in NK cell activity, were able to lyse MHV-infected target cells, as were spleen cells from nude mice, which are deficient in T cell activity. Lysis of MHV-infected target cells could be mediated by cells from the spleen and, to a lesser extent, by cells from the bone marrow, but not by resident peritoneal cells or thymocytes. We suggest the term "virus killer (VK) activity" for this phenomenon. VK activity of splenocytes from different mouse strains correlated with the ability of the splenocytes to bind purified radiolabeled MHV virions. MHV virions caused agglutination of spleen leukocytes from susceptible mouse strains, indicating that leukocyte agglutination or adsorption may provide a useful assay for coronaviruses such as MHV which lack hemagglutinating activity. SJL mouse splenocytes did not bind MHV and did not lyse infected targets. MHV bound relatively well to splenocytes of other mouse strains, but poorly to thymocytes and erythrocytes. Binding of MHV to leukocytes was not influenced by 6 mM EDTA or EGTA, indicating a lack of requirement for Mg++ or Ca++. VK activity was also resistant to EDTA and EGTA, in contrast to NK activity, which was sensitive to those chelating agents. VK activity was also unaffected by actinomycin D, cycloheximide, or puromycin, indicating that new protein synthesis was not required for lysis. Antibody to interferon-alpha/beta did not block lysis, nor was there substantially enhanced lysis mediated by leukocytes from mice infected with virus and thus exposed to high levels of interferon. VK activity was blocked by antibody directed against the peplomeric glycoprotein E2 of MHV. VK activity required infected target cells, because cells with adsorbed MHV virions were not lysed by splenocytes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Natural cytotoxicity against mouse hepatitis virus-infected target cells. I. Correlation of cytotoxicity with virus binding to leukocytes. 300 98

In this study, we describe the origin and characterization of a new metastatic tumor cell line (p11-R-Eb) obtained after i.p. passages of the nonmetastatic Eb lymphoma cells into DBA/2 mice. The p11-R-Eb cells exhibited the same morphology and in vitro growth properties and chromosome markers as the original Eb cells. FACS analysis of the p11-R-Eb cells also revealed a close similarity to the Eb cells. Moreover, the p11-R-Eb cells were specifically killed by anti-Eb cytotoxic lymphocytes. In spite of all these characteristics of the Eb line, p11-R-Eb cells metastasized to the liver when injected i.v. or s.c. in DBA/2 mice. Peritumoral interleukin (IL)-2 treatment resulted in a potent antitumor response in DBA/2 mice transplanted s.c. with p11-R-Eb cells. In contrast, the same IL-2 regimen did not significantly increase the survival time of mice transplanted with the highly metastatic ESb cell line. Combined IL-1/IL-2 treatments of established p11-R-Eb tumors resulted in a synergistic antitumor effect and in tumor regression in 70% of the injected mice. Similarly, combined peritumoral treatment with IL-1 and interferon-alpha/beta, which were poorly effective or ineffective as single cytokine therapy, resulted in a marked antitumor effect, and 30% of the mice were cured. Spleen cells from IL-1/IL-2-treated p11-R-Eb-cell-injected mice showed a marked antitumor activity when assayed in a Winn assay with homologous tumor cells. This antitumor activity was eliminated by preincubation of spleen cells with antibodies to CD4 and complement and markedly inhibited by anti-asialo GM1 antibodies. P11-R-Eb cells represent, therefore, a new tumor model which may be useful for investigating the relevant mechanisms which need to be activated to achieve a potent antitumor response to cytokine therapy in the DBA/2 mouse host.
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PMID:Isolation and characterization of a metastatic Eb-like tumor variant highly responsive to interleukin (IL)-2 and to combination cytokine therapy with IL-2/IL-1 beta and IL-1 beta/interferon-alpha/beta. 811 75

Polynucleotides enhance T cell-dependent antibody production in culture. Impaired antibody production in mice fed a nucleotide-free diet can be easily restored by in vivo supplementation of both a mononucleotide-nucleoside mixture (OG-VI) and polynucleotides. Polynucleotides appear to act partly by modulating antigen presentation processes mediated by cell surface molecules. We examined whether dietary fatty acid manipulation alters nucleotides' actions on humoral immunity. Antibody production was studied in C57B1/6 mice fed I) a nucleotide-free diet high in saturated fatty acid (SFA diet), 2) a nucleotide-free diet high in polyunsaturated fatty acid (PUFA diet), and 3) a regular nucleotide-free diet (control). In vivo and in vitro T cell-dependent antibody production decreased in all groups, but mice fed the SFA diet produced more antibody in vivo than did mice in the other diet groups. Spleen cells from mice fed the SFA diet also produced more interferon-alpha when stimulated with mitogens than did those from mice fed the control diet. In contrast, polynucleotides enhanced in vitro antibody production much less efficiently in mice fed the SFA diet than in the other mice and in vivo supplementation of OG-VI was also less effective in restoring impaired antibody production in these mice. A diet with a high content of SFA may alter nucleotides' action on humoral immune responses, in addition to its direct effects on immune functions.
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PMID:Dietary fatty acid modulates actions of nucleotides on humoral immune responses. 874 95

Combination therapy using reovirus type 3 and the chemo-therapeutic agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) is sufficient to cure approximately 80% of EL-4 lymphoma tumor-bearing BD2F1 male mice. Cured animals can be challenged with the EL-4 tumor, in the absence of the therapy, to yield 100% survival, whereas those challenged with heterologous tumor produce 0% survival. These results strongly suggest that a host-immune response is responsible for the observed therapeutic effect. Reovirus, a double-stranded RNA virus, is an efficient inducer of type I interferon. In an effort to determine the role of virus in this therapy, we substituted interferon-alpha (IFN-alpha) for reovirus in the therapy. Doses of IFN-alpha from 1000-10,000 U were capable of replacing reovirus to produce cure rates similar to reovirus. Spleen cells isolated from therapy-treated animals demonstrated high levels of cytotoxicity against the natural killer cell-sensitive cell line YAC-1, but not against EL-4 tumor. In vitro stimulation of isolated spleen cells by IFN-alpha resulted in a high level of natural killer cell activity, but no cytotoxicity against the EL-4 tumor. A significant antiproliferative effect against the EL-4 tumor in cell culture was demonstrated by IFN-alpha. Finally, therapy-treated, tumor-bearing mice that were injected with anti-IFN-alpha + -beta antibodies had similar survival levels as control mice, indicating that other cytokines might also play a role in promoting tumor killing. These investigations suggest that IFN-alpha may be a mediator of antitumor activity in the reovirus therapy system.
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PMID:The role of interferon-alpha in a successful murine tumor therapy. 1598 24

The spread of dengue (DEN) worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Progress in understanding DEN pathogenesis and in developing effective treatments has been hampered by the lack of a suitable small animal model. Most of the DEN clinical isolates and cell culture-passaged DEN virus strains reported so far require either host adaptation, inoculation with a high dose and/or intravenous administration to elicit a virulent phenotype in mice which results, at best, in a productive infection with no, few, or irrelevant disease manifestations, and with mice dying within few days at the peak of viremia. Here we describe a non-mouse-adapted DEN2 virus strain (D2Y98P) that is highly infectious in AG129 mice (lacking interferon-alpha/beta and -gamma receptors) upon intraperitoneal administration. Infection with a high dose of D2Y98P induced cytokine storm, massive organ damage, and severe vascular leakage, leading to haemorrhage and rapid death of the animals at the peak of viremia. In contrast, very interestingly and uniquely, infection with a low dose of D2Y98P led to asymptomatic viral dissemination and replication in relevant organs, followed by non-paralytic death of the animals few days after virus clearance, similar to the disease kinetic in humans. Spleen damage, liver dysfunction and increased vascular permeability, but no haemorrhage, were observed in moribund animals, suggesting intact vascular integrity, a cardinal feature in DEN shock syndrome. Infection with D2Y98P thus offers the opportunity to further decipher some of the aspects of dengue pathogenesis and provides a new platform for drug and vaccine testing.
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PMID:A non mouse-adapted dengue virus strain as a new model of severe dengue infection in AG129 mice. 2043 20