MU IFN-alpha Research Articles

The Impact of Age on the Response of Patients With Superficial Bladder Cancer to Intravesical Immunotherapy

We determined the influence of age on response to intravesical immunotherapy in patients with superficial bladder cancer. Data from a national phase II multicenter trial for BCG plus IFN-alpha intravesical therapy for superficial bladder cancer were analyzed. Recurrence-free survival 2 years after the initiation of therapy was examined in patients by incremental age decade. BCG-N patients received 81 mg BCG and 50 MU IFN-alpha, while patients who had previously been treated with BCG received a third of the BCG dose with 50 MU IFN-alpha and those who were BCG intolerant received a tenth of the BCG dose with 100 MU IFN-alpha. Kaplan-Meier survival curves were obtained. In all patients the largest difference in response was between the 289 who were 61 to 70 years old and the 123 who were older than 80 years with a 22% difference in cancer-free survival at a median followup of 24 months (61% vs 39%, p = 0.0002). When we assessed BCG-N and BCG treated patients separately in the 2 age groups, patients older than 80 years had a persistently lower response rate than younger patients 61 to 70 years old. Of BCG-N patients those older than 80 and younger than 50 years had the lowest cancer-free survival at a median followup of 24 months (47% and 45%, respectively). On multivariate analysis age was an independent risk factor for response. Aging appears to be associated with a decreased response to intravesical immunotherapy and is particularly apparent in patients older than 80 years. A potential explanation could be their depressed baseline immune status and consequent inability to mount an immune reaction to BCG or IFN-alpha.

Combination therapy with interferon‐α and ribavirin in patients with dual hepatitis B and hepatitis C virus infection

Patients with dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection have responded poorly to interferon (IFN) monotherapy. The purpose of the present paper was to assess the effect of combined IFN-alpha and ribavirin therapy in patients infected with both hepatitis B and C. Thirty-six patients received 3 or 5 MU IFN-alpha-2b thrice weekly and oral ribavirin (800-1200 mg/day) for 24 weeks. All patients had positive hepatitis B surface antigen, antibody to HCV, and HCV-RNA. Before treatment, one patient had positive hepatitis B e antigen. Eighteen patients had positive HBV-DNA tested by Amplicor (Cobas Amplicor Monitor, Roche Diagnostics, Branchburg, NJ, USA), with a mean HBV-DNA level of 3.1 +/- 0.9 log copies/mL. Another 72 patients with HCV infection alone served as controls. Adverse events led to withdrawal in three patients receiving 5 MU IFN. Based on an intent-to-treat analysis, the biochemical response and serum HCV clearance rate at the end of 48 weeks follow up was similar in patients with dual infection and HCV infection alone (56% vs 72%; and 69% vs 71%, respectively). There was no significant difference in sustained HCV clearance rate between the 3-MU group (n = 13) and the 5-MU group (n = 23; 85% vs 61%). At the end of 48 weeks follow up, two (11%) of 18 pretreatment viremic patients had negative serum HBV-DNA (<200 copies/mL), while eight of those without pretreatment viremia had re-occurrence of HBV-DNA. Combination therapy with IFN-alpha and ribavirin was effective in achieving sustained HCV clearance in patients with dual HBV and HCV infection, comparable to those with hepatitis C infection alone. Combination therapy using 3 MU IFN-alpha seemed as effective as 5 MU, and was well tolerated in the study population. However, large-scale control trials are necessary to clarify these findings.

Pilot study of interferon-alpha high-dose induction therapy in combination with ribavirin plus amantadine for nonresponder patients with chronic hepatitis C.

Ribavirin plus interferon-alpha (IFN alpha) combination has led to a marked advance in the treatment of IFN alpha-naive or relapser patients with chronic hepatitis C but was shown to be only marginally effective in IFN alpha-nonresponders. We therefore conducted a pilot study to see whether an intensified treatment protocol might be more effective in inducing a virological response in patients who had not responded virologically to previous IFN alpha monotherapy. 14 nonresponder patients with histologically proven chronic hepatitis C were included in the study. Patients received 9 MU IFN alpha-2a daily for one week followed by 9 MU IFN alpha every second day for further 5 weeks. With the beginning of the seventh week, patients were treated with 6 MU IFN alpha thrice in week (tiw) for a period of 6 weeks (until week 12). IFN alpha was continued up to 48 weeks at a dose of 3 MU IFN alpha tiw. Ribavirin (1000-1200 mg/day) and amantadine sulphate (200 mg/day) was given orally for 48 weeks. One patient discontinued therapy after first IFN alpha injection and one other patient after 12 weeks of therapy because of side effects. The remaining 12 patients completed treatment according to the protocol. An initial virological response at week 24 was achieved in 2 of the 14 patients (14%) and both patients remained HCV RNA negative at the end of treatment. However, both patients relapsed 4 weeks after completion of therapy, and therefore none of the patients achieved a virological sustained response. Viral dynamics studies showed a marked decline in hepatitis C viremia during the first 6 weeks of high-dose IFN alpha. After IFN alpha dose reduction, however, viremia stabilized or increased in most patients. These data indicate, that even triple therapy with high-dose IFN alpha plus ribavirin and amantadine fails to improve significantly the response rates in IFN alpha-nonresponders.

Efficacy of 3 vs. 5 MU IFN-alpha given daily followed by a tiw maintenance regimen in chronic hepatitis C: a randomized trial

Efficacy of 3 vs. 5 MU IFN-alpha given daily followed by a tiw maintenance regimen in chronic hepatitis C: a randomized trial

Differential constitutive expression of interferon genes in early mouse embryos

Recent evidence suggests that several processes during mammalian embryogenesis may be regulated by IFNs or IFN-like molecules. With the use of MAPPing, the simultaneous presence of transcripts homologous to IFN-alpha, IFN-beta, IRF-1, and IRF-2 was examined in mouse embryos and in embryonal carcinoma (EC) P19 cells, which are equivalent to epiblast cells of the early postimplantation blastocysts. Transcripts for IFN-alpha, but not for IFN-beta, were detected as maternal transcripts in the ovulated oocyte and persisted over early embryogenesis. IRF-1 transcripts appeared only after the first cell cleavage in the two-cell stage embryo. IRF-2 transcripts were analyzed only in EC P19 cells and were found in both undifferentiated (D-) and differentiated (D+) cells. The IFN-alpha transcripts present in (D-) P19 cells were cloned and the partial cDNA sequences determined. Mu IFN-alpha A and a new Mu IFN-alpha species (Mu IFN-alpha 12) were isolated from (D-) P19 cells. The presence of constitutive IFN-alpha transcripts in early mouse embryos suggests a role for these molecules during embryogenesis.

Double modulation of 5-fluorouracil with interferon α2a and high-dose leucovorin: a phase I and II study

Twenty-nine patients with adenocarcinomas of gastrointestinal or unknown primary, and three with advanced neuroendocrine tumours, were entered into a study of bolus plus infusional 5-fluorouracil (FUra) modulated with high-dose leucovorin (LV) and recombinant interferon alpha 2a (IFN-alpha). Successive cohorts of > or = 4 patients received IFN-alpha at 1.5, 3, 4.5, 6 and 9 MU on alternate days throughout the treatment period. The FUra/LV regimen consisted of: LV 200 mg m-2 i.v. infusion over 2 h, FUra 400 mg m-2 i.v. bolus then FUra 400 mg m-2 i.v. infusion over 22 h, all repeated on day 2, on a 14-day cycle. FUra was given at 75% dose for the first course, increasing (in the absence of WHO grade > or = 2 toxicity) to 87.5% for the second and 100% for subsequent courses up to a maximum of 12. The maximum tolerated dose (MTD) of IFN-alpha was 6 MU on alternate days, with 7/8 patients at 9 MU requiring dose reductions. At 6 MU IFN-alpha, the MTD of FUra was not exceeded at 100% (i.e. 400 mg m-2 bolus and infusion, days 1 and 2), and FUra-related toxicities (mucosal, haematological, dermatological) were extremely mild. Twenty-nine patients were assessable for tumour response, among whom WHO criteria partial responses were seen in 7/14 with colorectal, 1/4 with gastric, 0/1 with pancreatic, 1/3 with neuroendocrine and 3/6 with unknown primaries. Median response duration was 51 weeks. Minor responses and stable disease were seen in a further six patients. Median survival of patients with advanced adenocarcinomas was 9 months, with 33% surviving beyond 18 months. This schedule offers a safe way of co-administering FUra, LV and IFN-alpha. The addition of IFN-alpha, while causing significant independent toxicity, does not significantly increase the dose-limiting mucosal toxicities of FUra/LV. Further investigation is required to determine the contribution of IFN-alpha to the anti-tumour activity of the combination.

Sequence and expression of a novel murine interferon alpha gene — Homology with enhancer elements in the regulatory region of the gene

A murine interferon gene (MuIFN alpha) has been isolated from a cosmid library. The sequence of a 1.2-kb HindIII-PstI fragment revealed a new MuIFN alpha gene which has not yet been described and which was termed MuIFN alpha 7. The coding sequence produced biologically active IFN when expressed in monkey cells under the control of an SV40 promoter. A comparison of the MuIFN alpha 7 gene with the known interferon genes in their coding and flanking sequences shows homologies between enhancer elements found in the 5' upstream region of the coding gene. The core element common to all known viral enhancers, GTGG(AAA/TTT)G is repeated four times in the MuIFN alpha 7 5'-flanking region, as in all known MuIFN alpha genes.

Segregation of restriction fragment length polymorphism in an interspecies cross of laboratory and wild mice indicates tight linkage of the murine IFN-beta gene to the murine IFN-alpha genes.

Southern blot analysis with murine (Mu) interferon (IFN)-alpha cDNA of restricted genomic DNA of three inbred strains of mice belonging to the species Mus musculus domesticus (BALB/c, C57BL/6, and DBA/2) revealed only a limited degree of polymorphism. For example, with HindIII there were only two polymorphic bands out of 14 hybridizing fragments. With Mu IFN-beta cDNA there was no polymorphism at all between BALB/c and C57BL/6 in DNA restricted with seven different enzymes. In contrast, HindIII-restricted DNA of an inbred strain of wild mice (M. spretus Lataste) hybridized with the IFN-alpha probe displayed a high degree of polymorphism compared with the three strains of laboratory mice and was also polymorphic when probed with IFN-beta cDNA. Although M. musculus domesticus and M. spretus Lataste represent different species, certain interspecies crosses are possible in the laboratory. This enabled us to follow segregation of restriction fragment length polymorphism in HindIII-restricted DNA obtained from 18 backcross progeny of a (DBA/2 X M. spretus)F1 X DBA/2 interspecies cross. There was complete coincidence between the segregation of parental (DBA/2) and (DBA/2 X M. spretus)F1-type IFN-beta and IFN-alpha restriction fragment length polymorphism, indicating tight linkage of the IFN-beta and IFN-alpha genes. In addition, in 15 of 18 progeny the segregation coincided with that of the brown locus on chromosome 4, in accord with previous results obtained with the IFN-alpha probe in strains derived from crosses between BALB/c and C57BL/6 mice. Thus, the Mu IFN-beta gene is tightly linked to the Mu IFN-alpha gene cluster on chromosome 4 near the brown locus.

Organization, structure and expression of murine interferon alpha genes.

Using a human interferon-alpha probe we have isolated recombinant phages containing murine interferon-alpha (Mu IFN-alpha) genes from a genomic library. One of these phages contained two complete Mu IFN-alpha genes and part of a third gene. The insert of a second phage held two IFN genes. This indicates that the Mu IFN-alpha genes are clustered in the genome as is the case for the analogous human genes. The nucleotide sequences of these 5 genes were determined. They show that the genes are all different, albeit highly homologous. The deduced amino acid sequences show that four of the five genes contain a putative glycosylation site. Three genes were transiently expressed in COS cells and they gave rise to protein products showing antiviral properties. The expression of the five Mu IFN-alpha genes and the Mu IFN-beta gene was studied in virus-induced mouse L cells. The individual mRNAs were visualized in a nuclease S1 experiment, using a specific probe for each gene. In RNA preparations from induced cells mRNAs for each of the five alpha genes and the beta gene were present. However, substantial differences in the amounts of the individual mRNAs were observed.

Herpes simplex virus persistence in mouse neuroblastoma (C 1300) cell cultures: role of interferon.

The Mp strain of herpes simplex virus type 1 (HSV1) induced a persistent infection in the mouse C 1300 neuronal cell line (clone N 115). C 1300 cultures infected at an MOI of 0.01 or 0.001 survived the initial infection and continued to produce infectious virus and viral antigens for 185 days and 31 days, respectively. Viral antigens were not detected in cultures no longer producing infectious virus; these "cured" cultures had comparable susceptibility to reinfection with HSV as previously uninfected C 1300 cells. While significant amounts of interferon were produced by C 1300 cells when challenged with Newcastle Disease Virus (NDV) or when treated with poly I:C, HSV-induced interferon could not be detected in either the acutely or persistently infected cell lines. The persistent state was not significantly altered by the addition of 1,000 units/ml of murine interferon alpha plus beta (MuIFN alpha + beta), nor was it affected by the addition of antibody to MuIFN. It appears that IFN does not play an important role in the establishment and/or maintenance of viral persistence in this neuronal system.

Enhanced production of murine interferon gamma by T cells generated in response to bacterial infection.

Spleen cell cultures derived from animals infected 6 d earlier with Listeria monocytogenes produced 10-20-fold more murine interferon gamma (MuIFN gamma) than spleen cells from nonimmune mice in response to stimulation with T cell mitogens. A striking temporal association was found between the enhanced synthesis of MuIFN gamma and the development of anti-Listeria immunity in that both the potential for increased MuIFN gamma production and the generation of Listeria-protective T cells developed and then decayed in unison. Treatment of spleen cells with monoclonal anti-Thy-1.2 plus complement virtually abolished the ability of cells from Listeria-immune mice to synthesize MuIFN gamma. The T cells producing MuIFN gamma were found to be more susceptible to complement-mediated lysis with monoclonal anti-Lyt-1.2 than with monoclonal anti-Lyt-2.2. The production of MuIFN gamma was not affected by treating spleen cells with anti-IgG antisera or with a monoclonal antibody directed against I-A specificities. MuIFN gamma was detected 4 h after the beginning of mitogenic stimulation of spleen cell cultures, and peak levels of MuIFN gamma were reached by 18 h. The IFN synthesized by mitogen-induced spleen cells derived from Listeria-immune mice were relatively labile at pH 2.0 and neutralized by a rabbit anti-MuIFN gamma serum but not by an antiserum having specificities for MuIFN alpha and MuIFN beta. The apparent molecular weight of the MuIFN gamma, as estimated by molecular sieving on a Bio-gel P-60 column, was estimated to be 38,000, and the isoelectric point as determined by chromatofocusing was extremely heterogeneous, ranging between pH 5.0 and pH 7.0.