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At least 19 recordsLinked to original sources
PubMed1989

The synergistic effect of human recombinant interferon-alpha 2a in combination with interferon-gamma and the induction of interferon-alpha 2a receptor by interferon-gamma.

An in vitro examination was made of the synergistic antiproliferative effect of recombinant interferon-gamma (IFN-gamma) with interferon-alpha 2a (IFN-alpha 2a) on human tumor cell lines, including lung small cell carcinoma QG-90, amelanotic melanoma HMV-1, renal carcinoma ACHN and Burkitt lymphoma Daudi. Sixty-four percent of HMV-1 cells and 75% of ACHN cells seeded were killed by treatment with 10 pM and 1000 pM of IFN-gamma, respectively. Furthermore, 69% of HMV-1 cells and 59% of ACHN cells were killed by 1000 pM of IFN-alpha 2a. When HMV-1 was treated first with 10 pM of IFN-gamma, and then with 1000 pM of IFN-alpha 2a, 81% of cells seeded were killed (p less than 0.001). Similarly, 89% of ACHN cells were killed by the same sequential treatment with 1000 pM IFN-gamma, and then of IFN-alpha 2a (p less than 0.001). However, adverse sequence of treatment could not produce such a synergistic result. On the surface of these susceptible cells, HMV-1 and ACHN, to both IFNs, the number of receptors for IFN-alpha 2a increased significantly after treatment with IFN-gamma without any serious change of the dissociation constant, suggesting that increase in the number of receptors for IFN-alpha 2a may be the major mechanism of the synergistic effects of IFN-gamma with IFN-alpha 2a.

Cell Division↗
PubMed1990

Interferons and bone. A comparison of the effects of interferon-alpha and interferon-gamma in cultures of human bone-derived cells and an osteosarcoma cell line.

Recombinant human interferon-alpha 2C and recombinant human interferon-gamma (5-1000 U/ml) inhibit the proliferation of normal human bone-derived cells and a human osteosarcoma cell line. In the bone-derived cells the inhibitory effect of interferon-gamma was significantly greater than that of interferon-alpha, whereas in the osteosarcoma cell line the inhibitory effects of both interferons were quantitatively similar. Interferon-alpha did not affect the alkaline phosphatase activity of either type of cells. In contrast, interferon-gamma affected the activity of the enzyme in both cell types: in the bone-derived cells the effect of interferon-gamma was stimulatory whereas in the osteosarcoma cells the effect was inhibitory. In both cell types interferon-gamma selectively inhibited the incorporation of radiolabelled proline into type I collagen. In the osteosarcoma cells, the effects of both interferons on collagen synthesis were quantitatively similar. In the bone-derived cells, however, interferon-alpha decreased proline incorporation into collagen and non-collagen proteins to a similar extent and thus did not affect collagen synthesis when expressed as a percentage of total protein synthesis. Two-dimensional polyacrylamide gel electrophoresis of the radiolabelled proteins of the cell layer synthesised by both cell types in the presence of either interferon demonstrated that this treatment enhanced or induced the synthesis of a total of 21 individual proteins (19 in bone cells, 14 in osteosarcoma), ranging in apparent molecular mass over 14-87 kDa. The set of proteins induced was different in all four combinations of cells and interferon. A tentative identification of several of the proteins was possible based upon estimation of molecular mass, preferential induction by interferon-alpha or interferon-gamma and differential induction in normal and transformed bone-derived cells. The results of this study demonstrate that interferons have complex effects upon the proliferative and biosynthetic activities of human bone-derived cells and demonstrate significant differences between the responses of normal cells and transformed bone-derived cell line. Further investigations will be required in order to determine whether or not these differences are unique to the osteosarcoma cell line or are a characteristic of the effects of interferons on bone-derived cells in general.

Adolescent↗
PubMed1986

Anti-tumor effects of interferon in mice injected with interferon-sensitive and interferon-resistant friend leukemia cells. IV. Definition of optimal treatment regimens.

Mouse interferon alpha/beta exerted a similar anti-tumor effect in DBA/2 mice injected i.p. with Friend erythroleukemia cells (FLC) either sensitive or resistant to interferon as determined by both in vitro and in vivo assays. Using this tumor system we attempted to define optimal treatment regimens for interferon administration. Interferon was most effective when injected at the site of tumor inoculation rather than at a distant site. Two factors seemed of especial importance: the amount of interferon injected and the frequency of interferon administration. Thus, for daily administration of interferon, the antitumor effect was directly related to the amount of interferon injected. For a given total dose of interferon, repeated administration of small doses of interferon was more effective than administration of a larger dose at more widely spaced intervals. The anti-tumor efficacy of interferon was independent of the number of FLC inoculated when 10(2) to 10(5) FLC were injected, but interferon treatment was less effective when 10(6) or 10(7) FLC were injected. The relevance of these results to the use of interferon in patients with cancer is discussed.

Animals↗
PubMed1990

Induction of interferon-alpha by interferon-beta, but not of interferon-beta by interferon-alpha, in the mouse.

The antigenicity of the interferon (IFN) produced in transgenic mice carrying an extra mouse IFN-beta gene under the control of mouse metallothionein-I enhancer-promoter was examined after induction with Cd2+. Unexpectedly, IFN-alpha in addition to IFN-beta was detected in the serum. Induction of IFN-alpha was also observed when recombinant mouse IFN-beta was injected into normal mice. IFN-alpha was first detected in the circulation 6-10 hr after the administration of IFN-beta, and after 12 hr, IFN-alpha became the major component of serum IFN. On the other hand, when IFN-alpha was injected, no production of IFN-beta was observed. Messenger RNAs specific for IFN-alpha and endogenous IFN-beta were detected in the spleen, though the amount of IFN-beta mRNA was much less than that of IFN-alpha mRNA. These mRNAs were not detected in other organs including the liver where exogenous IFN-beta gene was markedly expressed. These observations showed that the expression of IFN-alpha is inducible by IFN-beta in the mouse, and the spleen was suggested to be the main site of production. Possible mechanisms of the induction are discussed.

Animals↗
PubMed1990

Purification and cloning of interferon-stimulated gene factor 2 (ISGF2): ISGF2 (IRF-1) can bind to the promoters of both beta interferon- and interferon-stimulated genes but is not a primary transcriptional activator of either.

Interferon-stimulated gene factor 2 (ISGF2) was purified from HeLa cells treated with alpha interferon. The factor, a single polypeptide of 56 kilodaltons (kDa), bound both to the central 9 base pairs of the 15-base-pair interferon-stimulated response element (ISRE) that is required for transcriptional activation of interferon-stimulated genes and to the PRD-I regulatory element of the beta interferon gene. ISGF2 was a phosphoprotein, and dephosphorylation in vitro reduced its DNA-binding activity. However, conditions that changed the amount of ISGF2 did not change the phosphorylated isoforms in vivo. ISGF2 in unstimulated cells existed in trace amounts and was induced by both alpha interferon and gamma interferon as well as by virus infection. Plasmid-bearing Escherichia coli clones encoding ISGF2 were selected with antibody against purified ISGF2. Sequence analysis revealed that the ISGF2 protein was the same as that encoded by the cDNA clone IRF-1, which has been claimed to activate transcription of interferon genes. We show that transcription of the ISGF2 gene was induced by alpha interferon, gamma interferon, and double-stranded RNA. However, ISGF2 was neither necessary nor sufficient for induced transcription of the beta interferon gene, while the factor NF kappa B was clearly involved.

Base Sequence↗
PubMed1985

Isolation of Daudi cells with reduced sensitivity to interferon. III. Interferon-induced proteins in relation to the phenotype of interferon resistance.

The pattern of both constitutive and interferon-induced proteins was determined by two-dimensional gel electrophoresis in parental and interferon-resistant clones of Daudi cells in relation to the phenotype of interferon resistance. The complement of constitutive proteins present in clones DIF3, DIF8, DIF9 and DIF10 appeared to be identical to that of parental Daudi cells even though these cells were resistant to both the antiviral and anti-proliferative actions of interferon. Treatment of Daudi cells for 20 h with 10(3) reference units/ml of electrophoretically pure human interferon-alpha resulted in the induction of 15 proteins of molecular weights ranging from 15000 to 62000 detected after a 4 h labelling period with L-[35S]methionine. A number of these proteins were also induced in interferon-resistant clones of Daudi cells although some of these proteins appeared later and in smaller amounts than in the interferon-treated parental cells. However, seven proteins with molecular weights ranging from 18000 to 58000 which were induced by interferon in parental Daudi cells were not induced in any of the four interferon-resistant clones, suggesting that the phenotype of interferon resistance of these cells may be related to a reduction or absence of certain interferon-induced protein(s).

Cells, Cultured↗
PubMed1987

Effect of interferon alpha, interferon beta, and interferon gamma on the in vitro growth of human renal adenocarcinoma cells.

Interferon-alpha, interferon-beta, and interferon-gamma differ in their antiproliferative effects for several cell lines. Interferons were thus assessed for their activity in inhibiting proliferation of three renal cell carcinoma cell lines. The malignant epithelial phenotype of each of these cell lines was confirmed by electron microscopy, histology, karyotype and tumorigenicity. When compared on an anti-viral unit basis, naturally produced interferon-beta was more effective than natural interferon-alpha for all cell lines and clones. Proliferation of each of the cell lines was inhibited by interferon-gamma. In all cases, removal of interferons from culture media resulted in resumption of the rate of cell growth after a variable delay of 6-10 days. If the antiproliferative effects of interferons predominate in mediating tumor regression, clinical response may depend upon the type of interferon to which the tumor is exposed.

Adenocarcinoma↗
PubMed1986

31P-nuclear magnetic resonance analysis of interferon-induced alterations of phospholipid metabolites in interferon-sensitive and interferon-resistant Friend leukemia cell tumors in mice.

Adult DBA/2 mice were given injections s.c. with either interferon-sensitive (745) or -resistant (3Cl-8) Friend erythroleukemia cells (FLC). After tumor nodules had developed, mouse interferon-alpha/beta was injected daily into the tumor. 31P-Nuclear magnetic resonance (NMR) spectroscopy examinations were undertaken on freshly dissected tumors at different days of treatment with either interferon or control preparations. Analysis of 745 FLC tumors in untreated mice at different days of tumor growth (day 8 to 13 after tumor implantation) showed marked increases in the levels of phosphorylcholine (PCho), glycerophosphorylethanolamine (GroPEtn) and glycerophosphorylcholine (GroPCho). In contrast high levels of PCho, GroPEtn and GroPCho were already detectable in the 3Cl-8 FLC tumors on day 8, and no significant changes were observed during subsequent tumor growth. The intracellular pH value remained practically constant in both FLC tumors. Daily intratumoral administration of either partially purified (10(7) IU/mg of protein) or highly purified (10(9) IU/mg of protein) mouse interferon-alpha/beta to both cell tumors resulted in decreases in the levels of PCho, GroPEtn and GroPCho and in increases in the intracellular pH with respect to tumors treated with control preparations or left untreated. Two days of daily treatment of mice with interferon sufficed to induce these metabolic changes which preceded the appearance of necrosis in the tumors. Treatment of FLC tumors with X-rays on day 12 of tumor growth did not result in any comparable metabolic changes 2 days after irradiation. Changes in the levels of phospholipid metabolites were not observed when 745 or 3Cl-8 cells were cultivated in the presence of interferon. As interferon induced these changes in both interferon-sensitive and -resistant tumors we conclude that interferon treatment results in host-mediated effects on the biosynthesis and/or catabolism of tumor cell phospholipids.

Animals↗
PubMedDate not supplied

Effect of mouse interferon alpha/beta on the expression of H-2 (class I) antigens and on the levels of 2'-5' oligoadenylate synthetase activity in interferon-sensitive and interferon-resistant Friend leukemia cell tumors in mice.

DBA/2 mice were injected intraperitoneally (i.p.) with interferon-sensitive 745 or interferon-resistant 3C1-8 Friend erythroleukemia cells (FLC) and then injected i.p. with mouse interferon alpha/beta. Interferon enhanced the expression of histocompatibility (H-2) antigens on individual 745 FLC within the peritoneum, but did not alter the expression of H-2 antigens on individual 3C1-8 FLC. Likewise, interferon treatment resulted in an increase in the level of 2'-5' oligo-adenylate (2-5A) synthetase activity in 745 FLC, but did not affect the level of activity in 3C1-8 FLC. These results provide evidence that the phenotype of interferon sensitivity or resistance of FLC does not change within the peritoneum. An incidental finding was that the basal level of 2-5A synthetase activity of in vivo passaged 745 cells was greater than that of 3C1-8 FLC. The finding that injection of mice bearing 745 FLC with antibody to mouse interferon alpha/beta reduced the level of 2-5A synthetase activity in these cells, but did not alter the level of 2-5A activity in 3C1-8 FLC, suggests that endogenous interferon in the peritoneum may have been the responsible factor.

2',5'-Oligoadenylate Synthetase↗
PubMed1990

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

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, we could induce them individually and study their independent properties. Induction of ISGF3 gamma but not of ISGF3 alpha needed ongoing protein synthesis and was blocked by 2-aminopurine. Once induced, ISGF3 gamma was active for 24 h and was present in both the nuclear and cytoplasmic fractions. Activated ISGF3 alpha, on the other hand, did not translocate to the nucleus in the absence of ISGF3 gamma, and in the cytoplasm its activity decayed within 2 h of its activation. In reference to our working model, all of the above observations indicate that ISGF3 gamma is the product of signal 1 and ISGF3 alpha is the product of signal 2.

Base Sequence↗
PubMed1990

[The immunomodulating action of interferon. The change in the rosette-forming activity of human blood lymphocytes under the influence of gamma-interferon and recombinant alpha 2-interferon].

The authors analyze their findings in the study on the effects of interferon preparations (immune gamma-interferon and recombinant alpha 2-interferon) on the ability of blood lymphocytes of dermatoses patients and normal subjects to enter the rosette formation. Preliminary cell treatment with gamma-interferon in vitro essentially influences lymphocytic rosette forming activity, the initial functional activity of cellular receptor system being of paramount importance here. gamma-interferon increased cellular rosette-forming activity and virtually did not influence the unchanged parameters in the patients with lowered values by spontaneous and early active E-RFC. Besides that immune interferon increased the count of 'heavy' rosettes detectable in spontaneous and active E-rosette formation. Recombinant alpha 2-interferon did not essentially alter the blood lymphocyte receptor system.

Adjuvants, Immunologic↗
PubMed1991

Effects of interferons on cultured human melanocytes in vitro: interferon-beta but not-alpha or -gamma inhibit proliferation and all interferons significantly modulate the cell phenotype.

The effects of human recombinant interferon-alpha-2a (rIFN-alpha), natural interferon-beta (nIFN-beta) and recombinant interferon-gamma (rIFN-gamma) on the proliferation, morphology and antigen expression of cultured human melanocytes were studied in vitro. The investigations were performed in 12-O-tetradecanoylphorbol-13-acetate (TPA)- and serum-containing melanocyte growth medium (MGM), in TPA- and serum-free complete melanocyte medium (CMM) and its mitogen reduced variant (RMM). In MGM, none of these interferons inhibited the growth of normal melanocytes at concentrations 1-10,000 international units (IU)/ml over a period of 5 d. Only nIFN-beta, dose dependently, inhibited melanocyte proliferation in CMM and RMM in a 6- and 12-d assay (growth inhibition at 10,000 IU/ml; 77-80% of the controls, p less than 0.001). In contrast, rIFN-alpha and rIFN-gamma exerted no (RMM), or minor effects (CMM) on melanocyte proliferation (only in 12-d assays at 10,000 IU/ml: 24% and 21% of the controls respectively, p less than 0.01). In parallel experiments performed on melanoma cells, all three interferons were potent inhibitors of proliferation in a 5-d serum-free assay (growth inhibition at 10,000 IU/ml; rIFN-alpha 59%, nIFN-beta 78%, rIFN-gamma 56%, all p less than 0.001). In addition, nIFN-beta and also rIFN-gamma caused striking morphologic changes of normal melanocytes in vitro. Especially under greater than or equal to 10 IU/ml rIFN-gamma cytoplasmic spreading and flattening of the cultured melanocytes and their nuclei were seen, thus resembling melanoma cells in vitro. Untreated human melanocytes grown in MGM showed high expression of the melanoma-associated antigens HMB-45 (95-100%) and K.1.2 (40-100%), whereas the progression marker A.1.43 was present only on less than 5% of the cells. Cultured melanocytes were 95-100% positive for histocompatibility antigen class I (HLA-I), 30-75% were positive for ICAM-1, whereas they were negative for HLA-DR. After treatment with rIFN-alpha, increased expression of HLA-I antigens was found; nIFN-beta and rIFN-gamma decreased the labeling with HMB-45 (75-100%) and with K.1.2 (25-80%), whereby the expression of A.1.43 was found slightly increased (5-15%). The HLA class I antigens were upregulated by both nIFN-beta and rIFN-gamma, nIFN-beta being the most potent agent. Also, both nIFN-beta and rIFN-gamma increased the expression of ICAM-1 (nIFN-beta, 75-90%; rIFN-gamma, 90-95%) and induced de novo expression of HLA-DR antigen (nIFN-beta, 15-20%; rIFN-gamma, 65-95%).(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1986

Anti-tumor effects of interferon in mice injected with interferon-sensitive and interferon-resistant Friend leukemia cells. V. Comparisons with the action of tumor necrosis factor.

A number of similarities and dissimilarities in the anti-tumor effects of TNF and interferon alpha/beta have been observed in DBA/2 mice injected with Friend erythroleukemia cells (FLC). Mouse TNF exerted marked anti-tumor effects in mice injected either s.c. or i.p. with FLC lines 3C18 or 3 gamma R8 resistant in vitro to the cytotoxic effects of TNF. Likewise, mouse interferon alpha/beta had anti-tumor activity in mice injected with these FLC, resistant to the action of interferon alpha/beta or gamma in vitro. The results of histopathologic examination and 31P nuclear magnetic resonance analyses of 3C18 FLC s.c. tumors injected with TNF resembled the results previously obtained for 3C18 FLC tumors injected with interferon alpha/beta, although the effects of TNF occurred more rapidly. Injection of mice with antibody to mouse interferon alpha/beta or gamma did not abrogate the anti-tumor effects of TNF in mice injected i.p. with FLC. Our results suggest that in this experimental system the anti-tumor effects of TNF, like interferon alpha/beta, do not result from a direct effect on the tumor cells themselves but are host-mediated.

Animals↗
PubMed1985

The synergistic influence of human interferon-gamma and interferon-alpha on suppression of hematopoietic progenitor cells is additive with the enhanced sensitivity of these cells to inhibition by interferons at low oxygen tension in vitro.

The influences of human interferons--natural gamma (2 X 10(7) NIH reference U/mg), recombinant gamma (approximately 5 X 10(6) U/mg), natural alpha (1.4 X 10(8) international reference U/mg), and natural beta (10(6) international reference U/mg)--were evaluated alone or in combination for their effects in vitro on colony formation by low density human bone marrow granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells incubated at 5% CO2 in normal incubator (approximately 20%) O2 tension or low (5%) O2 tension. Alone, these interferons demonstrated the same dose response inhibitory curves, as we reported previously, when cells were grown at 20% O2. Recombinant IFN-gamma gave the same dose response curve as natural IFN-gamma. Natural or recombinant interferon synergized with IFN-alpha to suppress colony formation at concentrations that were approximately 2 log units lower than that required by either interferon alone. Equal concentrations of these interferons were not needed for the synergistic effect and were still apparent when one was present at concentrations of 2 log units less than the other. IFN-gamma synergized to a lesser extent with IFN-beta, but IFN-alpha did not synergize with IFN-beta. Cells grown at 5% O2 were more sensitive to inhibition by 2 log units less IFN-gamma or IFN-alpha, and this effect was additive with the synergistic effects of IFN-gamma and IFN-alpha together. These results may have physiological, pathological, and/or clinical relevance.

Bone Marrow Cells↗
PubMed1990

Effects of combinations of interferon-beta ser and interferon-gamma on interferon-inducible proteins and on the cell cycle.

SKCO 1 human colon carcinoma cells have been shown to be synergistically inhibited in their growth by the combinations of alpha-interferon (IFN-alpha) or beta-interferon (IFN-beta ser) and gamma-interferon (IFN-gamma). To determine if a correlation could be established between this synergistic antiproliferative effect and a synergistic induction in IFN-inducible proteins, or a unique perturbation in the cell cycle, we studied the effects of IFN-beta ser and IFN-gamma, alone and in combination, on 2',5'-oligoadenylate (2-5A) synthetase, indoleamine-2,3-dioxygenase (IDO), a human analogue of the murine Mx protein (p78), and the phases of cell cycle. 2-5A synthetase was maximally induced after a 24-h exposure to both IFN-beta and IFN-gamma. A synergistic enhancement of 2-5A synthetase activity was observed only with low concentrations of each IFN (0.05 ng/ml). IDO activity was induced by IFN-gamma and the combination of IFN-beta ser and IFN-gamma, but not IFN-beta ser alone. The differences in IDO activity between IFN-gamma and the combination, however, were not statistically significant. The p78 protein was induced in a dose-dependent manner by IFN-alpha and IFN-beta ser. IFN-gamma enhanced the expression of p78 induction by IFN-alpha or IFN-beta ser, even at concentrations of IFN-gamma that did not induce the protein when administered as a single agent. The combination of IFN-alpha and IFN-beta ser, which results in an antagonistic antiproliferative effect, also resulted in an antagonistic induction of p78. No changes in the cell cycle were observed following exposure to IFN-beta ser, IFN-gamma, or the combination, and treatment with IFN-gamma did not inhibit the accumulation of cells in G2M caused by colchicine. Thus, the synergistic antiproliferative effect produced by IFN-beta ser and IFN-gamma in SKCO 1 cells could not be correlated with a synergistic enhancement in 2-5A synthetase or IDO activity, or with a perturbation in the cell cycle. In contrast, the combination of IFN-gamma and IFN-alpha or IFN-beta ser synergistically enhanced the expression of p78 protein in these cells.

2',5'-Oligoadenylate Synthetase↗
PubMed1987

Anti-tumor effects of interferon in mice injected with interferon-sensitive and interferon-resistant Friend leukemia cells. VI. Adjuvant therapy after surgery in the inhibition of liver and spleen metastases.

Adult DBA/2 mice were injected s.c. with the highly malignant, interferon-resistant 3C18 line of Friend erythroleukemia cells (FLC). Eight or 9 days after established s.c. tumors had developed, the primary tumor was excised and mice were treated i.p. with either mouse interferon alpha/beta or a control preparation. At the time of surgery, mice already had tumor cells in the liver. All control-treated mice died in the ensuing 2 weeks with extensive tumor metastases in the liver and spleen. Interferon treatment resulted in an inhibition of the development of liver and spleen metastases and a markedly increased survival time. We conclude that interferon alpha/beta is effective as adjuvant therapy after surgery for metastatic disease in mice.

Animals↗