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1.  Mechanism of Interferon Action: Inhibition of Viral Messenger Ribonucleic Acid Translation in L-Cell Extracts 
Journal of Virology  1972;10(6):1184-1198.
Encephalomyocarditis (EMC) virus ribonucleic acid (RNA) stimulated the incorporation of 14C-amino acids into polypeptides in cell-free systems using preincubated S10 extracts from L cells. Incorporation was linear for over 2 hr. Analysis of the tryptic peptides derived from the polypeptide products formed in response to EMC RNA showed them to be virus specific. The major product, a polypeptide of 140,000 in molecular weight, migrated on sodium dodecyl sulfate-polyacrylamide gels with one of the virus-specific polypeptides present in EMC-infected cells. A minor component of molecular weight about 230,000 may correspond to the product of complete translation of the EMC virus genome. Little or no effect of interferon or vaccinia virus infection was observed in the preincubated, cell-free system. The EMC RNA-stimulated incorporation of 14C-amino acids into polypeptides was not inhibited in extracts derived from L cells early in virus infection, from interferon-treated cells, or from cells subjected to both treatments. Interferon treatment did appear to have a slight inhibitory effect on chain elongation in this system. However, treatment of cells with highly purified interferon before virus infection caused a decrease of about 80% in the capacity of non-preincubated cell extracts to translate added EMC RNA. This effect did not extend to the translation of polyuridylic acid and could be reversed by preincubation of the extracts at 37 C for 20 min. The inhibition of translation was manifest at interferon concentrations as low as 5IU/ml, and in this respect closely paralleled the inhibition of virus growth. Inactivation of the antiviral activity of the interferon by heating or digestion with trypsin also abolished the effect on cell-free protein synthesis. The EMC-specific polypeptides formed in reduced amounts in extracts of interferon-treated vaccinia-infected cells were smaller than those formed in extracts of untreated, vaccinia-infected cells. Thus, inhibition of initiation or elongation of polypeptides, or both, can be demonstrated in cell-free systems employing non-preincubated extracts from interferon-treated, virus-infected cells. These results indicate that antiviral activity of interferon is directed against the translation of viral messenger RNA.
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PMCID: PMC356600  PMID: 4345494
2.  Induction of alpha interferon by human immunodeficiency virus type 1 in human monocyte-macrophage cultures. 
Journal of Virology  1991;65(11):6362-6364.
The induction of interferon (IFN) by human immunodeficiency virus type 1 (HIV-1) in primary, nonstimulated monocyte-macrophage cultures was studied. HIV-1 infection, as confirmed by p24 antigen levels in the cell supernatant, led to the production of alpha interferon (IFN-alpha) over 7 to 21 days following infection. In two of seven experiments, the IFN detected was acid labile. Coupled reverse transcription-polymerase chain reaction analysis confirmed the induction of IFN-alpha mRNA in cells of HIV-1-infected cultures.
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PMCID: PMC250359  PMID: 1920639
3.  Recombinant human gamma interferon inhibits simian malaria. 
Infection and Immunity  1986;53(3):628-630.
Prophylactic treatment with 0.1 mg of human gamma interferon per kg (body weight) per day completely suppressed experimental infection with Plasmodium cynomolgi B sporozoites in rhesus monkeys. Treatment with lower doses partially suppressed this infection. Prophylactic treatment with human gamma interferon, however, had no protective effect against trophozoite-induced infection, suggesting that the interferon effect was limited to the exoerythrocytic stage of parasitic development.
PMCID: PMC260838  PMID: 3091507
4.  Inhibition of Protein Synthesis in Cell-Free Systems from Interferon-Treated, Infected Cells: Further Characterization and Effect of Formylmethionyl-tRNAF 
Journal of Virology  1974;13(1):9-21.
The translation of encephalomyocarditis virus (EMC) RNA is markedly inhibited in cell-free systems from interferon-treated, vaccinia virus-infected L-cells (10, 11). The polypeptide products synthesized in response to EMC RNA in cell-free systems from these and untreated infected cells have been analyzed by electrophoresis on polyacrylamide gels. Qualitatively, the same EMC-specific polypeptides were synthesized throughout. In experiments using preincubated microsomes from normal Krebs cells to assay cell sap from L-cells which had been exposed to interferon prior to infection, only the amount of the EMC-specific polypeptide products was reduced. This result suggests that there is an inhibition very early in translation in interferon-treated, infected cells. Initiation seems a priori the more attractive site for this inhibition, but an effect shortly after initiation cannot be excluded. With unfractionated cell-free systems from interferon-treated infected L-cells, however, there appeared to be an additional minor inhibitory effect on polypeptide chain elongation, in that the EMC-specific polypeptides synthesized showed not only a reduction in amount but also a bias towards lower molecular weight. The formylated methionyl initiator tRNA (Fmet-tRNAF) was used as a further probe into the apparent effect on intiation. With this reagent we have confirmed that there is one major initiation site for the translation of EMC RNA in these cell-free systems. In addition, the results have shown that EMC-specific polypeptide chains initiated with Fmet escape the major interferon-mediated inhibition at or shortly after initiation.
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PMCID: PMC355252  PMID: 16789138
5.  Serum alpha interferon and lymphocyte inclusions in systemic lupus erythematosus. 
Annals of the Rheumatic Diseases  1985;44(2):104-108.
The relationship between serum acid-labile alpha interferon and tubuloreticular inclusions within the cytoplasm of circulating lymphocytes was studied in 46 patients with systemic lupus erythematosus. Elevated levels of interferon (greater than or equal to 8 IU/ml) were found in 17 patients and lymphocyte inclusions in 35. The mean serum interferon concentration in patients with lymphocyte inclusions was significantly higher than in patients without inclusions (17.2 versus 2.4 IU/ml, p less than 0.01). Inclusions were found in 16 of 17 patients with elevated interferon and also in 19 of 29 patients without interferon (p = 0.026). In lupus, serum interferon appears to be a sufficient though not an essential marker for the presence of lymphocyte inclusions.
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PMCID: PMC1001582  PMID: 2983625
6.  Interferon-induced revertants of ras-transformed cells: resistance to transformation by specific oncogenes and retransformation by 5-azacytidine. 
Molecular and Cellular Biology  1987;7(6):2196-2200.
Prolonged alpha/beta interferon (IFN-alpha/beta) treatment of NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintained a nontransformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3, cells. The PR retransformants reverted again with IFN, suggesting that DNA methylation is involved in IFN-induced persistent reversion.
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PMCID: PMC365343  PMID: 2439904
7.  Tunicamycin treatment inhibits the antiviral activity of interferon in mice. 
Infection and Immunity  1983;41(1):61-66.
Earlier we reported that tunicamycin (TM) treatment of L cells in vitro significantly enhances the antiviral activity of interferon (IFN) against viruses (such as vesicular stomatitis, Sindbis, and herpes simplex) which bud from membranes. However, no such enhancement of the antiviral activity of IFN by TM was observed against encephalomyocarditis virus (EMCV) (nonbudding). We were interested to know whether TM would similarly enhance the antiviral activity of IFN and IFN inducers in vivo against Semliki Forest virus (SFV) and EMCV infections in mice. It was observed that TM alone (0.001 to 5.0 micrograms per mouse) did not protect mice against infections of SFV and EMCV; instead, TM-treated mice died with virus-specific paralytic symptoms earlier than untreated animals. The enhanced mortality in TM-treated and SFV- or EMCV-infected mice was associated with the concomitant increase in virus titer in brain tissue. IFN significantly protected mice against SFV and EMCV infections. The antiviral protection of mice by IFN against both the viruses was markedly inhibited by TM administration. IFN inducers (polyinosinic acid-polycytidylic acid, 6-MFA [a mixture of proteins, polysaccharides, and double-stranded DNA isolated from Aspergillus ochraceus ATCC 28706]) protected a significant number of mice against SFV infection. However, no such protection was observed in mice injected with a combination of TM and IFN inducer. These results indicate that TM treatment inhibits the antiviral action of IFN or IFN inducers in vivo.
PMCID: PMC264743  PMID: 6190759
8.  Dissociation of interferon effects on murine leukemia virus and encephalomyocarditis virus replication in mouse cells. 
Journal of Virology  1981;37(2):827-831.
Two subclones of Swiss mouse cells infected with Moloney murine leukemia virus (M-MuLV) were tested for their response to interferon (IFN). Whereas M-MuLV production in the two subclones was inhibited to the same extent, one of the subclones was significantly more sensitive to IFN when the antiviral effect was measured by replication of encephalomyocarditis (EMC) virus. The same subclone was also more sensitive to the anticellular activities of IFN. Additionally, NIH 3T3 cells infected with M-MuLV were completely resistant to IFN actions when EMC virus replication or the anticellular activities were tested. However, under the same conditions, M-MuLV production was completely inhibited by IFN. These results indicate that IFN may affect cell growth functions and EMC replication through mechanisms different from those by which MuLV production is inhibited.
PMCID: PMC171071  PMID: 6163874
9.  Simian virus 40-specific ribosome-binding proteins induced by a nondefective adenovirus 2-simian virus 40 hybrid. 
Journal of Virology  1977;23(3):692-699.
We have studied the intracellular distribution of the two simian virus 40-specific proteins, with apparent molecular weights of 56,000 and 42,000, detectable in human KB cells infected by a nondefective adenovirus 2-simian virus 40 hybrid, Ad2+ND2. After a 20-min pulse of [35S]methionine, about two-thirds of the newly synthesized 56K protein and one-third of the 42K protein were found localized on the plasma membrane. The remainder of each protein was found in the cytoplasm, whereas the nuclear fraction was virtually free of either component. A significant portion of both proteins present in the cytoplasmic fraction was complexed to the 40S ribosomal subunits and was not removed by treatment with 0.5 M KCl. Moreover, the portion that was found free in the cytoplasm could bind preferentially and quantitatively to purified 40S ribosomes in vitro, leading us to propose that these simian virus 40 proteins may act as translational control elements in cells.
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PMCID: PMC515881  PMID: 197266
10.  Antiviral activity of interferons. 
Bacteriological Reviews  1977;41(3):543-567.
PMCID: PMC414016  PMID: 199154
11.  Fate of interferon-treated cells. 
Infection and Immunity  1976;13(2):487-493.
Interferon-treated cultures of Ly cells survived initial infection with high multiplicities of vesicular stomatitis (VSV) or herpes simplex virus (HSV). In the case of HSV, infectious virus and intracellular viral antigen were rapidly eliminated from the interferon-treated cultures, and the cells grew out to form apparently normal monolayers that could be cultured indefinitely. In the VSV-infected Ly cultures, virus titers remained at low levels in interferon-treated cells but after about 14 days rapidly rose and the culture was destroyed. If interferon was added to the medium on days 4 and 6 after infection, virus titers rapidly declined but again recovered and the cells were destroyed. If, however, interferon treatment was resumed 9 days after initial infection, detectable infectious VSV was eliminated from the medium. Several methods, including cocultivation and molecular hybridization, failed to demonstrate persistence of a significant portion of the VSV genome in these cultures.
PMCID: PMC420638  PMID: 177368
12.  Interferon-directed inhibition of chronic murine leukemia virus production in cell cultures: lack of effect on intracellular viral markers. 
Journal of Virology  1975;16(3):569-574.
Extracellular murine leukemia virus (MLV) reverse transcriptase activity was decreased by interferon treatment in four interferon-sensitive mouse cell lines which were chronic MLV producers. In three cell lines which were relatively insensitive to interferon, extracellular enzyme activity remained unchanged by interferon treatment. The concentrations of interferon used had no effect on DNA synthesis or cell replication of AKR,C+ cells which were chronic producers of AKR-MLV. In AKR,C+ cultures interferon treatment also had no effect on the level of intracellular viral reverse transcriptase activity in spite of an inhibition of extracellular enzyme activity. Treatment of AKRC+ cultures with interferon for 9 days inhibited extracellular viral reverse transcriptase levels throughout the period of treatment; however, the intracellular enzyme activity remained unchanged, and concentrations of viral p30 (gs) antigen were increased in the interferon-treated cells. When the cells were washed to remove interferon, however, virus production rapidly rose and intracellular p30 antigen fell to the levels of untreated AKR,C+ cells. These and previously reported results suggested that in interferon-treated AKR,C+ cells virus production is inhibited at a late step in the MLV replication cycle, either directly or through the inhibition of the production of a protein required for virus assembly.
PMCID: PMC354704  PMID: 51100

Results 1-12 (12)