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Prostaglandin E release from human monocytes treated with lipopolysaccharides isolated from Bacteroides intermedius and Salmonella typhimurium: potentiation by gamma interferon.

Nichols, F C; Peluso, J F; Tempro, P J; Garrison, S W; Payne, J B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1991 Português
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The purpose of this investigation was to examine gamma interferon potentiation of lipopolysaccharide (LPS) responses in human monocytes by using phenol-water-extracted (unfractionated) and highly purified LPS preparations isolated from Bacteroides intermedius and Salmonella typhimurium. Phenol-water-extracted LPS preparations from these bacteria were further purified by chromatography over Sepharose-CL-4B. LPS enrichment in pooled column fractions was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and quantitation of hydroxy-fatty acid and 2-keto-3-deoxyoctulosonic acid content, protein contamination, and anthrone-reactive material. Monocyte stimulation by LPS, measured as prostaglandin E (PGE) release, was assessed with and without gamma interferon treatment. Cells were either treated simultaneously with gamma interferon and LPS or pretreated with gamma interferon prior to LPS stimulation. PGE release from counterflow-isolated monocytes was quantitated during the 0- to 24-h and 24- to 48-h culture intervals. Contrary to previous results from this laboratory, phenol-water-extracted LPS preparations from B. intermedius and S. typhimurium were similar in their capacities to stimulate PGE release from monocytes. Molecular sieve chromatography was found to remove substantial amounts of high-molecular-weight polysaccharide contaminants only from the B. intermedius LPS but did not significantly alter the potency of either B. intermedius or S. typhimurium LPS. Gamma interferon cotreatment did not potentiate the release of PGE with any of the LPS preparations tested. However...

Three strains of influenza A virus (H3N2): interferon sensitivity in vitro and interferon production in volunteers.

Richman, D D; Murphy, B R; Baron, S; Uhlendorf, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/1976 Português
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Three antigenic variants of the H3N2 subtype of wild-type influenza A virus (representing the years 1968, 1972, and 1974) were examined for their sensitivity to interferon and for their ability to induce local respiratory tract interferon in volunteers. In addition, the time of appearance of symptoms in infected volunteers was correlated with the patterns of virus shedding and interferon production. The sensitivity to interferon and the ability to stimulate nasopharyngeal interferon were similarly high for all three strains. Symptomatic illness, peak virus shedding, and peak interferon response all occurred within a 26-h period. These findings imply that interferon or its inducers theoretically could be protective if applied prophylactically, but would be less efficacious when used therapeutically.

The interaction of human macrophages and lymphocytes in the phytohemagglutinin-stimulated production of interferon

Epstein, Lois B.; Cline, Martin J.; Merigan, Thomas C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1971 Português
Relevância na Pesquisa
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In studies of 13 normal adults to determine the blood cell types responsible for interferon production induced by phytohemagglutinin, the following observations were made. (a) In cultures containing 96-100% pure macrophages derived from blood monocytes, no interferon was detected in either the presence or the absence of phytohemagglutinin for up to 92 hr. (b) In cultures of 99.5-100% pure lymphocytes, low levels of interferon were detected in the presence, but not in the absence, of phytohemagglutinin. (c) An average fivefold increase in interferon titers occurred when pure lymphocytes were combined with the macrophages in culture with phytohemagglutinin. The peak response of interferon occurred at 68 hr after the initiation of the combined cultures. For maximum response, phytohemagglutinin was required for the duration of the culture, and both cell types in association were necessary. Medium from phytohemagglutinin-stimulated macrophages or lymphocytes could not substitute for the corresponding intact cell. However, frozen-thawed macrophages in combination with lymphocytes and phytohemagglutinin produced an intermediate interferon response. An increase in either cell type produced an increased response in the range studied: lymphocytes...

Interferon-alpha restores normal adhesion of chronic myelogenous leukemia hematopoietic progenitors to bone marrow stroma by correcting impaired beta 1 integrin receptor function.

Bhatia, R; Wayner, E A; McGlave, P B; Verfaillie, C M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1994 Português
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Treatment of chronic myelogenous leukemia (CML) with interferon-alpha frequently results in normalization of peripheral blood counts and, in up to 20% of patients, reestablishment of normal hematopoiesis. We hypothesize that interferon-alpha may restore normal adhesive interactions between CML progenitors and the bone marrow microenvironment and restore normal growth regulatory effects resulting from these progenitor-stroma interactions. We demonstrate that treatment with interferon-alpha induces a significant, dose-dependent increase in the adhesion of primitive long-term culture initiating cells and committed colony-forming cells (CFC) from CML bone marrow to normal stroma. Adhesion of CFC seen after interferon-alpha treatment could be inhibited by blocking antibodies directed at the alpha 4, alpha 5, and beta 1 integrins and vascular cell adhesion molecule, but not CD44 or intracellular adhesion molecule, suggesting that interferon-alpha induces normalization of progenitor-stroma interactions in CML. Because FACS analysis showed that the level of alpha 4, alpha 5, and beta 1 integrin expression after interferon-alpha treatment is unchanged, this suggests that interferon-alpha may restore normal beta 1 integrin function. Normalization of interactions between CML progenitors and the bone marrow microenvironment may then result in the restoration of normal regulation of CML progenitor proliferation...

Leukocytes and Interferon in the Host Response to Viral Infections II. Enhanced Interferon Response of Leukocytes from Immune Animals

Glasgow, Lowell A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1966 Português
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Glasgow, Lowell A. (University of Rochester School of Medicine and Dentistry, Rochester, N.Y.). Leukocytes and interferon in the host response to viral infections. II. Enhanced interferon response of leukocytes from immune animals. J. Bacteriol. 91:2185–2191. 1966.—The production of interferon was studied under in vitro conditions in peritoneal leukocytes or macrophages from mice immunized with Chikungunya virus (CV). Cultures of leukocytes obtained from animals immune to CV produced 2- to 10-fold greater amounts of interferon when exposed to an inoculum of CV than similar cell preparations from nonimmune, control animals. The viral inhibitor produced in increased quantity by CV-immune leukocytes had the biological and biochemical properties of interferon. The enhanced interferon production was inhibited by actinomycin D. This response of immune leukocytes was specific, and was initiated only by CV; it was not observed in leukocytes from animals immunized against other viruses which were challenged with CV. The presence of neutralizing antibody could not be related to this response. The observed increase in interferon production was not dependent upon an enhanced virus uptake. The data are presented as a possible new dimension of the “immune response” and may suggest a mechanism for the phenomenon of “tissue immunity.”

Evidence for a protective role of interferon in resistance to murine cytomegalovirus and its control by non-H-2-linked genes.

Grundy, J E; Trapman, J; Allan, J E; Shellam, G R; Melief, C J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1982 Português
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Murine cytomegalovirus (MCMV) induces rapid production of a partially pH 2-stable type 1 interferon, the serum level of which is controlled by non-H-2-linked host genes. The production of high, intermediate, and low levels of interferon was found in C3H/He, C57BL/10, and BALB/c mice, respectively, and the use of H-2 congenic mice on the BALB/c or C57BL/10 background showed that H-2-associated genes were not involved. Administration of large (up to 200,000 U) daily doses of partially purified type 1 (alpha plus beta) interferon failed to protect low-producer BALB/c or BALB.K strains from lethal infection. Treatment of the higher (C3H/He) or intermediate (C57BL/10) producer strains with anti-type 1 interferon antibody significantly reduced their resistance to the virus; however, such treatment had no effect on the low-producer BALB/c strain. The decreased resistance of anti-interferon-treated C3H/He mice was accompanied by a transient reduction in serum interferon titers, decreased activation of natural killer cells, a markedly enhanced viremia, and increased viral titers in the liver. These data strongly support a protective role of interferon in defense against MCMV in certain strains of mice. Furthermore, these data suggest that previous observations of a correlation of non-H-2-linked...

Gamma interferon production in allogeneic stimulation: antigenicity that is sufficient to cause interferon production.

Ito, Y; Shimokata, K; Maeno, K
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1982 Português
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Spleen cells obtained from allogeneic cell-primed mice produced immune interferon when cocultivated with the antigenic cells. The purpose of this study was to clarify the antigenic determinants for immune interferon production in this allogeneic stimulation system. An incompatibility at the K end alone or at the D end alone of the H-2 complex was sufficient for immune interferon induction. No interferon production was observed in the combinations between strains of mice that differ for the non-H-2 regions, including the M locus. Immune interferon-producing cells (IIPC), induced by difference of the H-2K or H-2D regions, recognized the specificities controlled by the H-2K or H-2D regions, respectively; namely, there was no cross-reaction between the two regions. The difference between H-2d and H-2b did not cause interferon production in the combinations of which non-H-2 regions were very similar to each other. IIPC were not induced in the combination, but when IIPC were properly induced in B6 spleen cells, the IIPC could recognize the specificities controlled by the H-2d region (B10D2) and produced immune interferon.

Mouse genes influence antiviral action of interferon in vivo.

Dandoy, F; De Maeyer-Guignard, J; Bailey, D; De Maeyer, E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1982 Português
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BALB/c mice are more sensitive to the antiviral effect of interferon than C57BL/6 mice, as demonstrated by experiments involving protection against lethal infection with encephalomyocarditis virus. This greater sensitivity of the BALB/c genotype to interferon action is in accord with previous observations that the bone marrow-derived erythroid precursors and macrophages of BALB/c mice are more sensitive to the anti-proliferative action of interferon than those of C57BL/6 mice. An analysis of the loci involved in the modulation of the activity of interferon against encephalomyocarditis virus infection was carried out in (BALB/c x C57BL/6)F1 progeny and in six recombinant inbred lines originally derived from a BALB/c x C57BL/6 cross. The antiviral effect of exogenous interferon in the F1 progeny was comparable to the effect in BALB/c mice, indicating dominance of the greater sensitivity to interferon action. The results obtained with the six recombinant inbred lines suggested a multifactorial influence. In vitro, interferon pretreatment of encephalomyocarditis virus-infected BALB/c and C57BL/6 fibroblast cultures did not reveal a difference in sensitivity between the two mouse genotypes. This finding demonstrates that it is not always possible to extrapolate from in vitro to in vivo when sensitivity to interferon action is studied.

Interferon production by human mononuclear leukocytes: differences between respiratory syncytial virus and influenza viruses.

Chonmaitree, T; Roberts, N J; Douglas, R G; Hall, C B; Simons, R L
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1981 Português
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The ability of respiratory syncytial virus (RSV) to induce interferon production by human mononuclear leukocytes was compared with that of influenza viruses. Cell culture fluids were assayed for interferon activity 1, 3 and 7 days after exposure to RSV or to one of two subtypes of influenza A virus (H0N1 and H3N2). RSV induced interferon production inconsistently and in low titers. Varying the multiplicity of infection did not improve the ability of RSV to induce interferon production. In contrast, influenza viruses were effective inducers of interferon production. Seropositivity to the influenza virus strains was not associated with increased interferon titers. Interferon produced after exposure to RSV or to the influenza viruses was resistant to low pH treatment. The data suggest that interferon production may not be a major component of human immunological defense against RSV infection.

Species specificity of interferon action: maintenance and establishment of the antiviral state in the presence of a heterospecific nucleus.

Veomett, M J; Veomett, G E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1979 Português
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The expression of the interferon-induced antiviral state was studied in heterokaryons and cytoplasmic hybrids (cybrids). An autoradiographic assay for the antiviral state, in which the percentage of cells containing vaccinia viral DNA factories was determined, was used. The expression of the antiviral state was dominant in homokaryons and heterokaryons formed by fusion of interferon-treated cells with untreated cells. Cytoplasts derived from treated cells conferred resistance to virus growth on cybrids formed by fusing such cytoplasts with untreated cells. Treatment of L cell x HeLa cell heterokaryons with human interferon or mouse interferon was much less effective in inducing a detectable antiviral state than was similar treatment of parental cells with homospecific interferon. The antiviral state was fully induced when heterokaryons were treated simultaneously with both types of interferon. Cybrids formed by fusing L cell cytoplasts with HeLa cells or HeLa cytoplasts with L cells did not enter a detectable antiviral state after treatment with interferon specific for the cell type of the enucleated parent. However, treatment of cybrids with interferon specific for the cell type of the nucleated parent was effective in inducing a detectable antiviral state.

Post-Transcriptional Control of Interferon Synthesis

Vilček, Jan; Ng, Mun H.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1971 Português
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Low to moderate doses of cycloheximide had a stimulatory effect on interferon production in rabbit kidney cell cultures treated with double-stranded polyinosinate-polycytidylate (poly I:poly C). A very marked stimulation occurred in the presence of a dose of cycloheximide inhibiting amino acid incorporation into total cellular protein by about 75%. Higher doses of cycloheximide caused a shift in interferon release towards later intervals and a gradual decrease in the overall degree of stimulation. An even greater increase in the amount of interferon produced was observed if cells were treated with cycloheximide for only 3 to 4 hr immediately after their exposure to poly I:poly C. Under the latter conditions, a rapid burst of interferon production occurred after the reversal of cycloheximide action. Treatment with a high dose of actinomycin D before the reversal of cycloheximide action caused a further increase and a marked prolongation of interferon production. It is postulated that inhibitors of protein synthesis suppress the accumulation of a cellular regulatory protein (repressor) which interacts with the interferon messenger ribonucleic acid mRNA and thereby prevents its translation. Therefore, active interferon mRNA can apparently accumulate in rabbit kidney cells which...

Gene induction by interferons: functional complementation between trans-acting factors induced by alpha interferon and gamma interferon.

Bandyopadhyay, S K; Kalvakolanu, D V; Sen, G C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1990 Português
Relevância na Pesquisa
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HeLaM is a variant cell line in which the transcriptional induction of many genes by alpha interferon has special characteristics (Tiwari et al., Mol. Cell. Biol. 8:4289-4294, 1988). The same characteristics were also displayed for induced transcription of a permanently transfected chimeric gene containing the interferon-stimulated response element of gene 561. For understanding the molecular basis of the special requirements of HeLaM cells, an analysis of the interferon-stimulated gene factors (ISGF) was undertaken. By using gel shift assays, it was shown that the activation of ISGF3 by alpha interferon treatment of HeLaM cells had characteristics identical to those of induced transcription: inhibition by 2-aminopurine and the need for ongoing protein synthesis which was obviated by pretreating the cells with gamma interferon. Upon mixing in vitro the cytoplasmic fraction of gamma interferon-treated HeLaM cells with that of cells treated with alpha interferon and cycloheximide, active ISGF3 was reconstituted, presumably through complementation of two components, ISGF3 gamma and ISGF3 alpha, present in the two respective fractions. Because, unlike other cells, untreated HeLaM cells did not contain detectable levels of either component...

Interferon and Host Resistance to Rauscher Virus-induced Leukemia 1

Glasgow, Lowell A.; Friedman, Stanford B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1969 Português
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A random bred strain of mice (CD-1) was shown to develop resistance to Rauscher leukemia virus (RLV) as the animals matured. Resistant adult mice developed relatively high-serum levels of interferon (150 to 2,000 units per ml) in contrast to susceptible 21-day-old animals in which interferon levels were undetectable or low (less than 20 to 200 units per ml). A similar correlation between resistance and interferon levels was observed in comparisons between resistant CD-1 and susceptible BALB/c mice. The F1 hybrids of CD-1 × BALB/c and BALB/c × CD-1 matings manifested an intermediate degree of susceptibility and interferon production. The difference in interferon production by CD-1 and BALB/c mice was specific for the RLV-host interaction, since both strains produced equal serum levels of interferon in response to Sindbis and Newcastle disease viruses. The mortality of CD-1 suckling mice infected with Rauscher leukemia virus was decreased by treatment with interferon. These data demonstrate an association between interferon production by the host and the observed relative resistance of the CD-1 strain of adult mice to the subsequent malignant transformation. This virus-host relationship provides an excellent model for further study of factors affecting the development of virus-induced leukemia.

Characterization of an interferon receptor on human lymphoblastoid cells.

Faltynek, C R; Branca, A A; McCandless, S; Baglioni, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1983 Português
Relevância na Pesquisa
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A cell-free assay was developed to measure the binding of iodinated human interferon-alpha 2 to membranes prepared from lymphoblastoid Daudi cells. The kinetics of binding were similar at 0 degrees C and 30 degrees C, with 1.3-fold more interferon bound at the higher temperature. Membrane preparations treated with Triton X-100 proved to be a convenient source of solubilized receptor. An assay was developed to measure the binding of 125I-labeled interferon (125I-interferon) to solubilized receptors, based on the precipitation of interferon-receptor complexes with polyethylene glycol. Optimal binding with this assay was obtained at 0 degrees C. The solubilized receptor was analyzed by zonal sedimentation centrifugation and gel filtration. Sedimentation analysis in H2O and 2H2O gradients provided the sedimentation coefficient and the partial specific volume of the receptor-Triton X-100 complex. Gel filtration chromatography provided the Stokes radius of this complex. From these data we calculated several physical parameters, including Mr = 95,000 for the protein portion of the complex. The receptor is a highly asymmetric and hydrophobic membrane protein. 125I-Interferon could be crosslinked to receptors of intact Daudi cells or of isolated membranes by use of disuccinimidyl suberate. The covalently linked 125I-interferon-receptor complexes were analyzed by gel electrophoresis. A single band with Mr = 140...

Interferon Administered in the Cerebrospinal Space and Its Effect on Rabies in Rabbits

Ho, Monto; Nash, Carolyn; Morgan, Charles W.; Armstrong, John A.; Carroll, Robert G.; Postic, Bosko
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1974 Português
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Because combined administration of intramuscular and intravenous interferon has been partially successful in the incubationary treatment of rabies, the effect of direct interferon administration into the cerebrospinal fluid space was tested. After injecting 1,800 U of interferon into the cisterna magna or the lateral ventricle, periodic samples, obtained by cisternal taps, showed that 1 to 5% remained after 24 h, as opposed to the known clearance of interferon from the bloodstream to this level within minutes. The distributions of interferon and 131I-labeled albumin were similar as demonstrated by kinetics of clearance monitored over 24 h. Beginning with and after experimental infection of rabbits, daily intraventricular injections of one million units of interferon were given for as long as 3 weeks. Interferon was prepared from cell culture fluids after pressure dialysis and chromatography on Sephadex G-100. This intensive treatment did not prevent encephalitis, but prolonged the length of the incubation period by one- to two-thirds. The outcome after intraventricular administration was not as favorable as when one million units equally divided between intramuscular and intravenous injections were given at the time of challenge. Interferon administered in the subarachnoid space in this fashion is apparently inadequate to protect the rabbit against rabies. Its role as an adjunct measure...

Interferon Production by Macrophages from Adult and Newborn Rabbits Bearing Fibroma Virus-Induced Tumors

Pathak, P. N.; Tompkins, W. A. F.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1974 Português
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26.59%
Tumors were induced in adult and newborn rabbits by inoculation of fibroma virus. After 10 to 14 days, oil-induced peritoneal macrophages were harvested, purified, and tested in vitro for interferon synthesis after stimulation with specific and nonspecific viruses. Peritoneal macrophages from adult rabbits that had initiated tumor regression produced high levels of interferon (titers ranged from 160 to 640) after stimulation with fibroma virus, whereas macrophages from normal adult rabbits failed to produce significant levels of interferon under the same conditions (titers ranged from <10 to 10). Furthermore, fibroma-immune macrophages responded to vaccinia virus and Newcastle disease virus with higher levels of interferon than did normal macrophages. In contrast, macrophages from newborn tumor-bearing rabbits that showed no evidence of tumor regression failed to respond to fibroma virus stimulation with higher levels of interferon (titers ranged from <10 to 10). These macrophages did, however, yield significantly more interferon than newborn control macrophages when stimulated with a good interferon inducer, Newcastle disease virus (titers ranged from 10 to 80). These data suggest that interferon production may be an expression of macrophage activation to fibroma antigens and that macrophage activation is impaired in newborn rabbits with progressive growing tumors.

In vivo and in vitro stimulation of mouse spleen leukocytes by BL-20803, a low-molecular-weight interferon inducer.

Siminoff, P
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1975 Português
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26.59%
BL-20803, a low-molecular-weight compound, although able to elicit circulating interferon in the mouse, failed to protect cultured cell lines in vitro from infection by interferon-sensitive viruses. Of the tissues analyzed for interferon content after oral administration of the drug to mice, spleen and lung contained the largest amounts of the virus inhibitor. Spleen cells from such dosed animals when isolated into in vitro cultures elaborated small amounts of interferon into the culture medium. The time sequence of acquisition by spleen cells of the ability to produce interferon closely correlated with the kinetics of development of the circulating interferon response in the intact mouse. When spleen cells were separated on the basis of adherence or nonadherence to a plastic surface, the bulk of the interferon activity was found to be associated with the adherent cells. Upon exposure to BL-20803 in cell culture, adherent cells and, to a lesser extent, nonadherent cells from untreated mice were stimulated to produce interferon-like activity. The biological behavior of BL-20803 is shown to have striking similarities with that of the structurally different low-molecular-weight inducer tilorone hydrochloride.

Interferon Induction and Resistance to Virus Infection in Mice Infected with Brucella abortus

Billiau, A.; Schonne, E.; Eyckmans, L.; De Somer, P.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1970 Português
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Induction of circulating interferon and protection against vaccinia virus infection in mice by injection of Brucella abortus were studied. It was demonstrated that morphologically intact brucellae (either live or killed by heat or exposure to NaOH) induce high and prolonged levels of circulating interferon in mice. In each instance, the inducing principle remained associated with the bacterial particle. Disruption of brucellae by mechanical means destroyed the interferon-inducing capacity. However, by alkalinization of the water extract of disrupted bacilli, an interferon inducer could be rescued. On intravenous injection, this inducer caused a typical endotoxin type of interferon response with a peak value at 2 hr. Mice pretreated with cycloheximide showed an enhanced interferon response to the brucella extract, but a reduced reaction to live brucellae. The significance of these data, in relation to the triggering of de novo interferon synthesis by brucella, is discussed. It was also observed that small doses of brucellae protected mice for at least 1 month against vaccinia virus infection. High doses of heat-or alkali-killed brucellae protected the animals for only a short time, and disrupted brucellae did not afford any protection. Thus...

Rapid activation of the interferon system in vivo.

Dianzani, F; Gullino, P; Baron, S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1978 Português
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Experiments were carried out to study the kinetics of local interferon production in the subcutaneous tissues of rats stimulated with Newcastle disease virus. Specifically, the interferon produced and released in the extracellular fluids was collected at various intervals of time in micropore chambers implanted into the subcutaneous tissue of rats. Interferon was detected at moderate titers 1 h after induction, and it was present at high titer at 2 h. The interferon levels remained remarkably high in the samples collected after 3, 5, and 24 h, and in some rats it was still detectable after 48 and 72 h. Since control experiments showed that it requires 2 to 3 h for interferon to penetrate the chambers, it may be concluded that high concentrations of interferon are present in the extracellular fluid within 1 h of induction. The evaluation of the kinetics of production and of the concentrations attained in the extracellular fluid suggests that in a solid tissue a cell infected by a potent interferon inducer may produce interferon early enough and in sufficient quantity to protect neighboring cells before the production of progeny virions.

Immune interferon induced by phytohemagglutinin in nude mouse spleen cells.

Wietzerbin, J; Stefanos, S; Falcoff, R; Lucero, M; Catinot, L; Falcoff, E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1978 Português
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Phytohemagglutinin is able to trigger interferon synthesis in spleen cell cultures from nude (nu/nu) mice as effectively as in splenic cell cultures from haired, control (nu/+), thymus-bearing mice. A minor theta-bearing cell population present in the spleen of nude mice appears essential to phytohemagglutinin interferon production, although cooperating cells are also required. The properties of nude mouse phytohemagglutinin interferon are indistinguishable from those displayed by the interferon induced in thymus-bearing mouse spleen cell cultures. Both interferons are unstable at pH 2 and cannot be neutralized by an antiviral interferon serum; hence, their characteristics correspond to those described for type T interferon. As in the case of viral interferon, pretreatment of L cells with nude phytohemagglutinin interferon induced specific enhanced phosphorylation of a 67,000-molecular-weight protein in vitro when cell extracts were incubated with double-stranded RNA and gamma-[32P]ATP.