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PubMed1979

Interferon production in the murine mixed lymphocyte culture. I. Interferon production caused by differences in the H-2 K and H-2 D region but not by differences in the I region or the M locus.

Little has been made previously of the observation that interferon is generated in the murine mixed lymphocyte reaction (MLR). We have found high levels of interferon in the supernatants of MLR between spleen cells of mice of different H-2 type after one to two days of culture. Interferon production was also seen in strain combinations that differed only in the K or D region of the H-2 complex. There was no production of interferon in strain combinations differing in the M locus or in the I region of the H-2 complex. The latter combinations are known not to induce cytotoxic effector cells. Thus, there seems to be a dichotomy in allogeneic determinants between those of the I region and of the M locus inducing primarily lymphoproliferation, and those of H-2K and H-2D inducing cytotoxic activity and interferon production.

Animals↗

PubMed1979

Production of interferon in the murine mixed lymphocyte culture. II. Interferon production is a T cell-dependent function, independent of proliferation.

Interferon production occurs after two days of culture in murine mixed lymphocyte cultures (MLC). This was demonstrated in various combinations of mouse spleen cells differing at the major histocompatibility (H-2) locus. Interferon production could be demonstrated in one-way MLC when F1/parent combinations were used and in reactions in which one partner was treated by puromycin. After treatment of both cell populations with mitomycin C, interferon production occurred in the absence of lymphoproliferation. Interferon production in response to alloantigen did not occur in spleen cell cultures of nude mice and in cultures treated by anti-theta antiserum plus complement indicating that interferon production is a T cell-dependent function.

Animals↗

PubMed1978

Role of endogenous interferon in the anti-tumor effect of poly I-C and statolon as demonstrated by the use of anti-mouse interferon serum.

We have determined the effect of sheep anti-mouse interferon globulin on the anti-tumor effects of poly I-C, statolon, tilorone, pyran copolymer and BCG in mice inoculated with Ehrlich ascites or L 1210 lymphoma cells. Whereas the anti-tumor effects of poly I-C and statolon were nulified when mice were injected with immunoglobulins, the anti-tumor effects of pyran copolymer and BCG were not modified by this treatment. We conclude that interferon mediates the anti-tumor activity of poly I-C and statolon in these experimental systems. It is suggested that anti-interferon serum provides a direct method of determining whether other biologic effects attributed to viruses, poly I-C, statolon, tilorone, pyran copolymer (and possibly other interferon inducers) are mediated or not by interferon.

Animals↗

PubMed1988

Alpha-interferon treatment for adult T cell leukemia: low levels of circulating alpha-interferon and it's clinical effectiveness.

We describe a patient with adult T cell Leukemia to whom alpha-interferon therapy was highly effective. Although a combination chemotherapy (ACVP) first introduced was effective in reducing total leukocyte counts, the percentage of leukemic cells relative to total leukocyte counts was decreased first after the institution of alpha-interferon therapy. The patient is now under complete remission for four years. It was noted in this patient that circulating alpha-interferon, measured by a sensitive radioimmunoassay, was consistently low as compared with the value found in the age-, sex-matched healthy control (p less than 0.001). Since adult T cell leukemia is pathogenetically related to the retrovirus infection, low levels of circulating alpha-interferon of the patient may be important from both pathogenetic and therapeutic standpoints. Alpha-interferon therapy may be an useful additive for the chemotherapy of adult T cell leukemia.

Adult↗

PubMed1992

Three cases of posttransfusion hepatitis C treated with interferon-alpha. Confirmation of a carrier state by detection of hepatitis C virus RNA after interferon therapy.

Interferon therapy is useful for decreasing the serum ALT level and improving liver histology in patients with chronic non-A, non-B hepatitis. This study examined the effect of interferon therapy in acute cases of posttransfusion hepatitis C. We report on three cases in which interferon alpha was administered at 100-220.5 million units. HCV RNA became undetectable during interferon administration and the ALT level declined to the normal range. However, after the cessation of the therapy, the ALT level began to fluctuate and HCV RNA reappeared in two patients. We concluded that interferon therapy for the acute phase of posttransfusion hepatitis is useful for suppressing viral replication and quickly improving the ALT level, but it can not always prevent the development of chronic hepatitis. Furthermore, there was a close correlation between the profile of HCV RNA and that of the ALT level, indicating that the replication of HCV plays an important role in liver injury.

Adult↗

PubMed1992

Inhibition of lymphocyte proliferation by bovine trophoblast protein-1 (type I trophoblast interferon) and bovine interferon-alpha I1.

Bovine trophoblast protein-1 (bTP-1) is a Type I interferon secreted by the bovine trophoblast from about Day 15 of pregnancy. It is not known whether bTP-1 has functional properties in common with other interferons. The aim of the present study was to determine whether bTP-1 inhibits proliferation of lymphocytes induced by mitogens, mixed lymphocyte cultures (MLC) and interleukin-2 (IL-2) and, if so, whether this activity is similar to that of a related interferon, bovine interferon-alpha I1 (bIFN-alpha I1). Stimulation of lymphocyte proliferation caused by phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) was inhibited by bTP-1 and bIFN-alpha I1 without any reduction in cell viability. Maximum or near-maximum inhibition (less than 50%) was achieved at concentrations of 0.5-5.0 nM of bTP-1 and bIFN-alpha I1. Cells stimulated with PWM were less inhibited than cells stimulated with PHA and Con A. Both bTP-1 and bIFN-alpha I1 inhibited MLC to a greater degree than lectin-stimulated cells (maximum inhibition was 78% or greater). Also, bTP-1 and bIFN-alpha I1 slightly inhibited incorporation of [3H]thymidine ([3H]TdR) induced by the combination of phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), and calcium ionophore A23187. Finally, bTP-1 and bIFN-alpha I1 had bimodal effects on incorporation of [3H]TdR by IL-2-induced lymphocytes. Incorporation of [3H]TdR was increased at 0.005 nM and 0.05 nM concentrations while higher concentrations caused a slight decrease in [3H]TdR incorporation. Results confirm that bTP-1 inhibits lymphocyte proliferation in a manner similar to that caused by the leukocyte-derived interferon, bIFN-alpha I1. Incomplete inhibition of mitogen-induced proliferation and differences in degree of inhibition between various stimulators suggest that bTP-1 and bIFN-alpha I1 preferentially inhibit certain lymphocyte subpopulations. Local inhibition of lymphocyte proliferation caused by bTP-1 may help protect the allogeneic conceptus from immune responses to fetal antigens or regulate the release of cytokines from endometrial lymphocytes.

Animals↗

PubMed1989

Stability of human interferon-beta 1: oligomeric human interferon-beta 1 is inactive but is reactivated by monomerization.

Human interferon-beta 1 is extremely stable is a low ionic strength solution of pH 2 such as 10 mM HCl at 37 degrees C. However, the presence of 0.15 M NaCl led to a remarkable loss of antiviral activity. The molecular-sieve high-performance liquid chromatography revealed that, whereas completely active human interferon-beta 1 eluted as a 25 kDa species (monomeric form), the inactivated preparation eluted primarily as a 90 kDa species (oligomeric form). The specific activity (units per mg protein) of the oligomeric form was approx. 10% of that of the monomeric form. This observation shows that oligomeric human interferon-beta 1 is apparently in an inactive form. When the oligomeric eluate was resolved by polyacrylamide gel containing sodium dodecyl sulphate (SDS), it appeared to be monomeric under non-reducing conditions. Monomerization of the oligomeric human interferon-beta 1 by treatment with 1% SDS, fully regenerated its antiviral activity. These results suggest that the inactivation of the human interferon-beta 1 preparation was caused by its oligomerization via hydrophobic interactions without the formation of intermolecular disulphide bonds. These oligomers can be dissociated by SDS to restore biological activity.

Chromatography, High Pressure Liquid↗

PubMed1993

Interferon-alpha increases prostaglandin E2 production by cultured liver biopsy in patients with chronic viral hepatitis: can non-steroidal anti-inflammatory drugs improve the therapeutic response to interferon?

Arachidonic acid metabolites seem to play an important role in modulating the post-receptorial activity of interferon-alpha. In this study the effect of interferon-alpha on prostaglandin E2 production was evaluated in cultured liver tissue in 18 patients with chronic active hepatitis related to viral infection (9 hepatitis B virus (HBV) and 9 hepatitis C virus (HCV) positive) and in 7 uninfected patients with various liver diseases. The results show that interferon-alpha induces a significant increase in prostaglandin E2 production in both HBV and HCV chronic active hepatitis. Since the inhibition of the cyclooxygenase pathway increases antiviral protein synthesis and prostaglandin E2 has an immunosuppressive activity, this finding seems to suggest that a combined therapy (interferon-alpha plus non-steroidal anti-inflammatory drugs) should be indicated at least for patients who do not respond to interferon therapy alone.

Adolescent↗

PubMed2003

Combination therapy with interferon-alpha(2b), ribavirin, and amantadine in chronic hepatitis C nonresponders to interferon and ribavirin.

Standard therapies for the treatment of hepatitis C are ineffective in almost 50% of patients. Amantadine is an antiviral agent that may have activity against hepatitis C virus. In this pilot study, we evaluated the efficacy of a combination of interferon, ribavirin, and amantadine in patients with chronic hepatitis C who had previously failed 6-12 months of treatment with interferon and ribavirin. In this prospective open-label study, 23 patients were treated with a combination of interferon-alpha(2b) 3 million units subcutaneously three times per week, ribavirin 1000-1200 mg daily, and amantadine 100 mg twice daily for 6-12 months. Treatment was discontinued at 6 months if the patients had detectable HCV RNA by PCR. All patients were followed for 6 months after the completion of treatment. At the end of treatment, the biochemical response was 47% and the virological response was 30%. However, the rate of sustained virological response was only 13% (3/23). There were no unexpected side effects with triple therapy. In conclusion, triple therapy with interferon, ribavirin and amantadine resulted in a low sustained viral clearance in chronic hepatitis C patients who had previously failed interferon and ribavirin combination therapy.

Adult↗

PubMed1998

Interferon alpha with ribavirin for the treatment of chronic hepatitis C in non-responders or relapsers to interferon monotherapy.

BACKGROUND: A more effective therapy for chronic hepatitis C virus-infected patients is needed. AIM: To evaluate the efficacy, tolerance and timing of response to interferon alpha plus ribavirin in 60 patients with no response or reactivation after interferon alpha alone. METHODS: Sixty patients, 42 non-responders and 18 relapsers, received 3 million units three times weekly of interferon alpha-2b plus 1-1.2 g ribavirin daily, for 6 months. Basal biochemical and virological (HCV RNA and genotype) parameters were determined. Clinical examination, recording adverse effects, and laboratory tests, including viraemia, were carried out at 1, 2, 3 and 6 months. RESULTS: A significant (P < 0.001) progressive decrease of HCV RNA and alanine transaminase (ALT) levels was observed during treatment. On finalizing the sixth month, 42 patients (70%) had normal ALT and 26 (43.3%) were HCV RNA negative. Of these 26 complete responders, in 20 the viraemia was undetectable by the third month, while a late clearance at the sixth month of treatment was observed in six patients. Response rates were higher in previous responders to interferon alone (P < 0.05). Mild adverse effects appeared in 46 patients (79.6%), but only three were withdrawn due to serious side-effects. Significantly (P < 0.001), haemoglobin and leucocytes decreased, and bilirubin, ferritin and uric acid increased in the first month of treatment, with no changes thereafter. CONCLUSIONS: Interferon alpha plus ribavirin progressively decreased HCV RNA and ALT levels, achieving a complete response in the six months of treatment in 26 (43.3%) patients. This combined therapy was well tolerated.

Adult↗

PubMed2000

Iron reduction as an adjuvant to interferon therapy in patients with chronic hepatitis C who have previously not responded to interferon: a multicenter, prospective, randomized, controlled trial.

Hepatic iron concentration has consistently been observed as being directly correlated with the response to interferon therapy in chronic hepatitis C virus (HCV). We therefore conducted a randomized, controlled trial comparing iron reduction by phlebotomy with iron reduction followed by retreatment with interferon in 96 patients with chronic hepatitis C who had previously not responded to a course of interferon. During the initial phase when all patients were undergoing phlebotomy, we found that serum alanine transaminase (ALT) activities decreased but by less than 50% from baseline in 67 patients (89%), decreased by more than 50% in 12 patients (13%) and became normal in 9 patients (9%) with no overall change in HCV-RNA levels. Subsequently no patient in either treatment group achieved a sustained virologic response. Improvements in necroinflammatory changes were noted in liver biopsy specimens in those patients receiving phlebotomy plus interferon (mean index 8.59 vs. 7.37, P <. 05). A slight but not statistically significant decrease in histologic activity index was noted in those subjects treated by phlebotomy alone (mean index 8.4 vs. 7.75, P not significant). We conclude that, although prior phlebotomy therapy does not improve the rate of sustained response to interferon retreatment, it does result in less liver injury manifested by a decrease in serum transaminase activity and a slight improvement in liver histopathology.

Adult↗

PubMed1975

Interferon activity produced by translation of human interferon messenger RNA in cell-free ribosomal systems and in Xenopus oöcytes.

Translation of messenger RNA isolated from poly(rI)-poly(rC)-induced human fibroblasts in cell-free ribosomal systems and in Xenopus oocytes resulted in the production of biologically active proteins that had the properties of human fibroblast interferon. The translation in the oocytes was much more efficient, giving approximately 500 times higher titers of interferon activity than the cell-free systems. A control messenger RNA isolated from noninduced human fibroblasts, did not code for interferon synthesis in these systems. Both messenger RNA preparations stimulated [3H]amino-acid incorporation into trichloroacetic acid-insoluble material. The radioactive products and their immunoprecipitates were electrophoresed on polyacrylamide gels under denaturing conditions. The products resulting from the translation of the control (uninduced) messenger RNA in oocytes contained a major protein of approximately 45,000 molecular weight. The messenger RNA isolated from poly(rI)-poly(rC)-induced cells stimulated the synthesis of an additional 25,000 molecular weight protein that electrophoresed in the same position as human fibroblast interferon. These results suggest that human fibroblast interferon was synthesized by the translation of its messenger RNA in Xenopus oocytes and in cell-free ribosomal systems.

Animals↗

PubMed1980

Mechanism of interferon action: simian virus 40-specific early polypeptides synthesized in untreated and interferon-treated monkey kidney cells.

The effect of interferon treatment on proteins synthesized in simian virus 40 (SV40)-infected cells in the presence of cytosine arabinoside was investigated. The following results were obtained: (i) In addition to previously described large tumor (T) antigen (94 kilodaltons) and small tumor (t) antigen (19 kilodaltons), a 62-kilodalton polypeptide was immunoprecipitated by SV40 anti-T antiserum from extracts of infected CV-1 and BSC-1 monkey kidney cells and transformed SV3T3 mouse cells. The 94-, 62-, and 19-kilodalton polypeptides were not precipitated with normal serum from extracts of infected cells, and they were not present in extracts of uninfected cells. (ii) The de novo synthesis of the 94-, 62-, and 19-kilodalton tumor antigens was inhibited in CV-1 and BSC-1 cells treated with interferon before infection; total cellular protein synthesis was not significantly affected by interferon treatment. The relative interferon sensitivity of the three polypeptides in lytically infected monkey cells was comparable; by contrast, interferon did not affect their synthesis in transformed mouse cells. (iii) The 62-kilodalton polypeptide was detected in monkey cells infected with the following strains of SV40: tsA30 at both 33 degrees C and 41 degrees C; wt 708, the parent of tsA30; dI 884; and wt 830, the parent of dI 884. The amount of the 62-kilodalton species relative to T antigen was significantly greater in tsA30-infected cells as compared to cells infected with other SV40 strains. (iv) T, t, and 62-kilodalton polypeptides were readily labeled with [(35)S]methionine during a 10-min pulse; in a subsequent chase, the (35)S-labeled 94-kilodalton T antigen was apparently converted to 89- and 84-kilodalton polypeptides but not to either the 62-kilodalton polypeptide species or t antigen. (v) Partial peptide maps suggest that the 62-kilodalton polypeptide and T antigen are closely related. (vi) In addition to the above described 62-kilodalton polypeptide, a 54-kilodalton polypeptide was also detected. However, the 54-kilodalton species appears to be of cellular origin because it was immunoprecipitated with both normal and anti-T antiserum from uninfected and lytically infected cells and from virally transformed cells.

Animals↗

PubMed1982

Interferon increases HLA synthesis in melanoma cells: interferon-resistant and -sensitive cell lines.

We report that human leukocyte interferon preparations increase the expression of beta 2-microglobulin by 100-200% on the surface of normal fibroblast and melanoma cell lines sensitive to interferon. This increase in expression can be correlated with an increase in HLA synthesis as measured by incorporation of [35S]methionine in these antigens. This enhanced HLA synthesis, which is 5- to 17-fold, is time dependent and dose related. Synchronized cells in the G0/G1 phase of the cell cycle appear to be more sensitive to this interferon action. Neither an increase in surface expression nor in HLA synthesis is observed in a melanoma cell line resistant to the antiviral and antigrowth effects of interferon. Furthermore, there appears to be a stronger correlation between this increased HLA synthesis and the antiviral function than between it and the antiproliferative action of interferon.

Cell Division↗

PubMed1981

High yield culture of human fibroblasts on microcarriers: a first step in production of fibroblast-derived interferon (human beta interferon).

Production of large quantities of diploid human fibroblasts in small culture volumes can be achieved using microcarrier culture techniques. Modification of the microcarrier culture procedure to include a virtually static attachment period and a reduced culture volume during the first 6 hr of culture was shown to double the attachment efficiency of the cells, improve the culture growth rate and increase final cell yields. Using the modified culture procedure yields greater than 2 x 10(6) cells/ml could be regularly obtained when 7--8 viable cells/microcarrier were used to inoculate a culture containing 3 mg of Cytodex 1 microcarriers/ml. A protocol for the mass production of human beta interferon from microcarrier cultures is described. After priming the culture with beta interferon the superinduction step involves use of a poly (I) . poly(C)/DEAE-Dextran complex. Modifications to the microcarrier culture procedure and to the interferon production sequence enable the production of 3 x 10(8) IU of interferon from a 5 liter microcarrier culture of human fibroblasts. This quantity of interferon corresponds to a yield of approximately 30 IU/10(3) cells or 2 x 10(4) IU/mg of microcarrier.

Cells, Cultured↗

PubMed1985

An inhibitor of interferon action: II. Biological properties of the IFN-gamma-associated inhibitor of interferon action.

Previously an inhibitor of interferon action had been isolated from mitogen stimulated mouse spleen cells. This inhibitor was associated with the IFN-gamma molecule and might possibly represent an altered IFN-gamma molecule which can no longer induce an effective antiviral state. This report further investigates the biological properties of this inhibitor. Inhibitor activity is independent of the virus used in the interferon assay. Inhibitor activity has also been found to be species specific. Mouse inhibitor does not inhibit the antiviral activity of either human IFN-gamma or human IFN-beta. However, inhibitor production is not limited to the mouse system. Inhibitor is also present in preparations of human IFN-gamma. The inhibitor does not appear to directly compete with IFN-gamma for a specific cell surface receptor since inhibitor activity is independent of interferon concentration. The presence of inhibitor allows a unique, albeit reduced level of antiviral protection to develop. Increasing concentrations of interferon do not increase the level of antiviral protection allowed by the inhibitor. This inhibitor of interferon action may represent a natural mechanism whereby IFN-gamma-induced effects are regulated in vivo.

Animals↗

PubMed1976

Differential sensitivity of herpes simplex virus types 1 and 2 to human interferon: antiviral effects of interferon plus 9-beta-D-arabinofuranosyladenine.

With use of a standard assay for antiviral compounds, in which the compound to be tested is added after absorption of virus, the minimal inhibitory concentration (MIC) of human interferon for several strain of herpes simplex virus type 2 (HSV-2) is five to 10 times greater than it is for two strains of herpes simplex virus type 1 (HSV-1). This differential susceptibility of HSV types to interferon is found whether tests are done with a liquid overlay and microtiter plates or with agarose overlays and appears to be a distinguishing biological marker. When the MIC of interferon is tested by microtiter or agarose methods and interferon is allowed to incubate for 24 hr before virus is added, values for HSV-1 and HSV-2 are similar and much smaller in magnitude. These results support earlier data indicating that adenine arabinoside and interferon are synergistic against herpes simplex virus type 1 in vitro and indicate that these agents are additive but not synergistic against herpes simplex virus type 2.

Antiviral Agents↗

PubMed1975

Distinct molecular species of human interferons: requirements for stabilzation and reactivation of human leukocyte and fibroblast interferons.

Human fibroblast interferon preparations were completely stabilized to 100 degrees C by sodium dodecyl sulphate (SDS) in the presence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS without mercaptoethanol. On the contarary, human leukocyte interferon preparations were completely stabilized to 100 degrees C by SDS in the absence of mercaptoethanol, but only a minor fraction of their activities were stabilized by SDS in the presence of mercaptoethanol. Furthermore, human fibroblast interferon preparations whose activities had been destroyed by boiling at 100 degrees C were completely reactivated by SDS under reducing conditions, but only a minor part of their activities were restored by SDS in the absence of reduction. On the contrary, human leukocyte interferon preparations whose activities had been destroyed by boiling at 100 degrees C were completely reactivated by SDS in the absence of reduction, but only a minor part of their activities were restored by SDS under reducing conditions. These data suggest that there are distinct molecular species of human interferons.

Biological Assay↗