IFN Administration Research Articles

In vivotreatment with interferon causes augmentation of IL-2 induced lymphokine-activated killer cells in the organs of mice

Interferon-alpha (IFN-alpha) has been shown to synergize with IL-2 in the regression of a variety of established murine tumours and studies are underway to explore this combination in patients with advanced cancers as well. To understand the mechanism of synergy we have studied lymphokine-activated killer (LAK) cell activity in various compartments of mice in response to IFN-alpha and IL-2 administration. The effects of IFN-gamma, TNF-alpha and IL-4 were also examined. C57BL/6 mice were injected intraperitoneally with HBSS, IL-2 alone, IFN-alpha alone or both, two times a day for 7 days. On days 4 and 8, LAK activity was tested in a 4-h chromium release in cells obtained from lungs, spleen, and liver using fresh MCA-102 tumour cells as targets. The cells from control mice failed to lyse the MCA-102 target. IL-2 caused the generation of LAK activity and an increase in total cell yield in all the organs after 3 days of injection. IFN-alpha failed to generate LAK activity but when administered along with IL-2, caused synergistic enhancement of LAK lysis of MCA-102 target cells. Cell yield in this group was lower as compared with the IL-2-treated group. LAK activity tested after 7 days of IL-2 therapy was significantly decreased compared with that observed after 3 days. However, activity remained at as high a level after 7 days of therapy as after 3 days of therapy in animals treated with IFN-alpha and IL-2. FACS analysis revealed that asialo GM-1+ (ASGM-1) and NK1.1+ cells were increased in number in IL-2 and IL-2 plus IFN-alpha-treated spleen; however, the number of these cells was similar in both groups. In the liver, ASGM-1+ cells were higher in the IL-2 plus IFN-alpha group than in the group treated with IL-2 alone. By in vitro depletion utilizing antibody and Rbc' experiments, it was clear that both ASGM-1+ and NK1.1+ cells from the spleen mediated most of the cytotoxicity of MCA-102 targets. Pre-treatment irradiation (5 Gy) of mice completely abrogated the capability of IL-2 or IL-2 plus IFN-alpha to generate LAK activity. IFN-gamma also had a stimulatory effect on IL-2 induction of LAK activity. Tumour necrosis factor-alpha (TNF-alpha) and IL-4 failed to generate LAK activity and, in combination with IL-2, no additional stimulatory effect was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of sublingual administration of interferon-α on the immune response to influenza vaccination in institutionalized elderly individuals

A randomized double-blind placebo-controlled study was conducted to determine the effect of sublingual administration of IFNα on the immune response to influenza vaccination in elderly institutionalized individuals. Sublingual administration of 10 million IU of IFNα immediately prior to vaccination, reduced the geometric mean haemagglutination inhibitory (HAI) and IgG2 circulating antibody titers, and the secretory IgA (sIgA) response in saliva, to the New York strain of influenza A virus, 21 days post-vaccination, without detectable drug-related local or systemic toxicity. IFN treatment did not inhibit the immune response to the other components of the vaccine; the New Caledonia strain of influenza A virus, or the Jiangsu strain of influenza B virus. At the dose tested sublingual administration of IFNα reduces the immune response to influenza vaccination in elderly institutionalized individuals.

Combining tumor-targeted superantigens with interferon-alpha results in synergistic anti-tumor effects

In this study we explored the possibility of improving the anti-tumor potency of tumor-targeted superantigens (TTS) by combination treatment with interferon-alpha (IFN-α). TTS utilizes the powerful T cell activating property of the superantigen staphylococcal enterotoxin A (SEA) in fusion with an anti-tumor Fab-fragment to target this T cell activity against tumor cells. TTS fusion proteins have shown anti-tumor efficacy in a number of experimental tumor models including the B16 mouse melanoma transfected with a human tumor-associated antigen recognized by the C215 monoclonal antibody. IFN-α is approved for the treatment of solid tumors such as renal cell carcinoma and malignant melanoma and exerts immunomodulatory effects, which make it an appropriate candidate to combine with immunotherapy against cancer. Here we report that daily administration of IFN-α (20 000 U i.p.) enhances and sustains CD8 + T cell activation induced by the TTS C215Fab-SEA (10 μg i.v.) in C57Bl/6 mice, as reflected by increased and prolonged cell-mediated cytotoxicity against tumor cells ex vivo as well as by augmented serum IFN-γ levels. C215Fab-SEA synergized with IFN-α in reducing the number of lung tumors in B16-C215 melanoma bearing mice as compared to mono therapy. In a long term tumor survival experiment, the prolonged median survival time of the combination treatment was 3.5 and 7.7 times the prolonged median survival times of C215Fab-SEA and IFN-α monotherapies, respectively. Hence, the combination treatment provoked synergistic anti-tumor effects as measured by the number of lung tumors and markedly prolonged survival. The enhanced therapeutic efficacy correlated with a striking and sustained increase of CD8- and perforin-expressing tumor-infiltrating cells. These results suggest significant potential of combining TTS with IFN-α for human cancer therapy.

Inflammation Activates the Interferon Signaling Pathways in Taste Bud Cells

Patients with viral and bacterial infections or other inflammatory illnesses often experience taste dysfunctions. The agents responsible for these taste disorders are thought to be related to infection-induced inflammation, but the mechanisms are not known. As a first step in characterizing the possible role of inflammation in taste disorders, we report here evidence for the presence of interferon (IFN)-mediated signaling pathways in taste bud cells. IFN receptors, particularly the IFN-gamma receptor IFNGR1, are coexpressed with the taste cell-type markers neuronal cell adhesion molecule and alpha-gustducin, suggesting that both the taste receptor cells and synapse-forming cells in the taste bud can be stimulated by IFN. Incubation of taste bud-containing lingual epithelia with recombinant IFN-alpha and IFN-gamma triggered the IFN-mediated signaling cascades, resulting in the phosphorylation of the downstream STAT1 (signal transducer and activator of transcription protein 1) transcription factor. Intraperitoneal injection of lipopolysaccharide or polyinosinic:polycytidylic acid into mice, mimicking bacterial and viral infections, respectively, altered gene expression patterns in taste bud cells. Furthermore, the systemic administration of either IFN-alpha or IFN-gamma significantly increased the number of taste bud cells undergoing programmed cell death. These findings suggest that bacterial and viral infection-induced IFNs can act directly on taste bud cells, affecting their cellular function in taste transduction, and that IFN-induced apoptosis in taste buds may cause abnormal cell turnover and skew the representation of different taste bud cell types, leading to the development of taste disorders. To our knowledge, this is the first study providing direct evidence that inflammation can affect taste buds through cytokine signaling pathways.

Treatment of Patients Infected with Hepatitis C Virus and Presenting Extrahepatic Manifestations

Antiviral treatment should be performed with the samemedications (standard or pegylated interferon alpha (PEG-IFN-α, with or without ribavirin) and similar regimens, untiladditional controlled studies provide further information onthe treatment of mixed cryoglobulinemia (MC) related toinfection with the hepatitis C virus (HCV).Data regarding antiviral treatment of MC (Table 1) showthat this therapeutic approach should be the first choice dueto the antiproliferative and immunomodulatory effects of IFNand the usefulness of antiviral treatment, as demonstrated inmost studies. In addition, the strict correlation betweenvirological and clinical response, as well as the positive effectof inhibiting viral replication in the expanded B-cell clones,which is considered the pathogenic basis of MC, are reasonsto make this choice. However, IFN- α can also trigger or worsenautoimmune diseases [6,7].Renal insufficiency and neuropathies can occur or beworsened, and ulcer cicatrization may be prolonged. Therefore,treatment with IFN-α should be restricted to symptomaticpatients, with or without renal involvement, after the carefulevaluation of clinical and laboratory characteristics regardingautoimmunity during this period.In comparison with the antiviral treatment of chronichepatitis C, the antiviral treatment of MC is more complex dueto various reasons, such as the lack of standardized treatmentprotocols, the higher incidence of recurrence and thecontraindications to antiviral treatment (old age, severe hepaticdisease, acute nephritis and disseminated vasculitis). Inaddition, the interpretation of laboratory findings seems to bemore complex than in chronic HCV infection. In fact,biochemical markers of MC response (cryocrit, rheumatoidfactor or complement activity) can be more independent ofthe virological response than are alanine aminotransferase(ALT) levels.At the moment, antiviral treatment is suggested as thetreatment of choice for this condition, even when there is noindication of hepatic pathology. Patients with apparentlybenign manifestations of the disease (palpable purpura,arthralgia and mild fatigue) should not be treated or can besymptomatically treated with nonsteroidal anti-inflammatorydrugs. Special attention must be given to the treatment ofpatients with severe MC (with acute nephritis anddisseminated vasculitis).For these cases, the data areinsufficient to guarantee the safety of IFN administration, andwe therefore strongly suggest a cautious approach. It ispreferable to use an alternative therapeutic approach to allpatients for whom antiviral treatment is contraindicated ornot tolerated, as well as for those who did not respond toprevious treatment. Possible alternatives include the use ofcorticosteroids, immunosuppressants, plasmapheresis and ahypo-antigenic, or low-antigen-content, diet [8].Treatment should be individualized for each patientaccording to the severity of clinical symptoms, consideringother factors involved (age, comorbidities, etc.) and for alimited period of time (weeks or months) until the remission ofsymptoms. Any therapeutic approach must be avoided forclinically asymptomatic patients.

IFN-α Finds Its SOCS

One of the treatments for patients with metastatic malignant melanoma is interferon-α (IFN-α); however, the success rate is only 10 to 15%. Previous studies suggest that IFN-α treatment of T cell lines leads to increased production of members of the suppressor of cytokine signaling (SOCS) family of proteins, which are well characterized in their ability to inhibit cytokine signaling. SOCS1 and SOCS3 inhibit IFN-α-mediated signal transduction. Zimmerer et al. investigated the effect of IFN-α treatment on the abundance of SOCS mRNAs and proteins in primary cells from healthy donors and patients with metastatic melanoma. Real-time polymerase chain reaction analysis revealed that peripheral blood mononuclear cells (PBMCs) from healthy donors treated in vitro with IFN-α had increased amounts of mRNAs for SOCS1, SOCS2, SOCS3, and the SOCS family member, cytokine-inducible Src homology 2 (SH2)-containing protein (CIS). Western blot analysis of immunoprecipitates from PBMCs showed that the abundance of these SOCS family members was also increased after IFN-α treatment. Further cell-specific analyses demonstrated that the strongest effect of IFN-α treatment was found within T cells. Analysis of PBMCs from patients with metastatic melanoma 1 hour after intravenous administration of IFN-α showed increased amounts of the mRNAs for some SOCS family members analyzed in healthy donors. Treatment of SOCS1-deficient mice (in a mouse model of malignant melanoma) with IFN-α reduced tumors in 70% of mice, without side effects, whereas all of the IFN-α-treated wild-type mice died. These data suggest that modulating SOCS activity in the context of cytokine treatment may improve clinical outcome. J. M. Zimmerer, G. B. Lesinski, S. V. Kondadasula, V. I. Karpa, A. Lehman, A. RayChaudhury, B. Becknell, W. E. Carson III, IFN-α-induced signal transduction, gene expression, and antitumor activity of immune effector cells are negatively regulated by suppressor of cytokine signaling proteins. J. Immunol. 178 , 4832-4845 (2007). [PubMed]

Interferon Therapy for HCV-Associated Glomerulonephritis: Meta-Analysis of Controlled Trials

A relationship between hepatitis C virus (HCV) infection and chronic glomerulonephritis (GN) has been asserted on the grounds of epidemiological and experimental data. Although this suggests a role for an antiviral approach to HCV-associated GN instead of the more conventional immunosuppressive (or supportive) therapy, the optimal management of HCV related glomerulonephritis remains controversial. To compare antiviral with immunosuppressive therapy for HCV-associated GN. Meta-analysis of controlled clinical trials (CCTs) of the two treatments (antiviral versus immunosuppressive) of HCV-associated GN. We used the fixed or random effects model of DerSimonian and Laird, with heterogeneity and sensitivity analyses. The rate of proteinuria and serum creatinine decrease after therapy for HCV-associated GN were regarded as the most reliable outcome end-points. We identified six studies involving 145 unique patients with HCV-associated GN. Pooling of study results demonstrated that proteinuria decreased more commonly after IFN than corticosteroid therapy (OR 1.92 (95% CI, 0.39; 9.57), NS), P-test for heterogeneity, 0.06 (I2=52.9%). In a sensitivity analysis including only CCTs using standard IFN-doses, OR was 3.86 (95% CI, 1.44; 10.33, (P=0.007)), P-test for heterogeneity, 0.18 (I2=35.9%). No improvement of serum creatinine after IFN compared to immunosuppressive therapy was noted (OR, 0.59 (95% CI, 0.21; 1.65), NS), P-test for heterogeneity, 0.76 (I2=0%). Only three CCTs gave information on the rate of proteinuria decrease over follow-up (OR, 5.08 (95% CI, 0.69; 37.31), NS). A few major side effects were noted after IFN administration. Our meta-analysis indicates that standard IFN-doses were more effective than immunosuppressive therapy in lowering proteinuria of patients with HCV-related glomerulonephritis. However, no significant improvement in serum creatinine was seen by IFN or steroid therapy across the studies. Also, information on proteinuria recurrence after the completion of antiviral therapy was not sufficient. Prospective, randomized trials based on combined antiviral therapy (pegylated IFN plus ribavirin) with adequate dose and follow-up are required to assess the efficacy and safety of antiviral treatment of HCV-associated glomerulonephritis.

Leptin restores plasma cholesterol, glucose and weight loss induced by IFNα treatment

Leptin, an adipokine, a major regulator of food intake, was recently suggested to play a role in immune response. We previously showed that weight reduction following IFNα therapy is due, at least in part, to direct induction of adipose tissue apoptosis. We now studied the effect of leptin on IFNα treated adipocytes in vitro and in vivo. Diet induced obese C57/B6 mice were treated continually with recombinant (r) IFNαA/D + leptin (100 U/g body weight + 10 μg/day, respectably) or leptin (10 μg/day) alone for 8 days. Co-administration of IFNαA/D + leptin significantly reduced plasma cholesterol ( P < 0.001), glucose ( P < 0.007) and pro-apoptotic protein levels ( P < 0.05). Additionally, co-administration prevented loss of body weight due to adipocyte apoptosis. Thus, leptin co-administration with IFNαA/D decreases some of the side effects of IFNα administration such as weight loss, cholesterol and glucose levels.

Protection from lethal influenza virus challenge by oral type 1 interferon

The persistence of highly pathogenic avian influenza within wild bird populations has forged interest in control measures to limit a possible human pandemic. We therefore investigated the efficacy of low dose oral administration of IFN-α as a potential therapy against influenza infection in a murine model. We have identified an optimal low oral dose of IFN-α that when delivered daily as prophylactic therapy protects C57BL/6J mice from a lethal challenge with mouse adapted human influenza virus A/PR/8/34 (H1N1). These results provide strong support for the application of low dose type 1 IFN pretreatment to human influenza control.

Interferon-α: A Key Factor in Autoimmune Disease?

Interferon (IFN)-alpha is an effective drug for treatment of uveitis in Behçet's disease. This study was undertaken to investigate the mechanism of action of IFN-alpha in the treatment of various types of noninfectious sight-threatening uveitis. Eleven patients with refractory uveitis, and 13 healthy individuals were enrolled. The number of circulating plasmacytoid dendritic cells (pDCs) and their capacity to produce IFN-alpha in culture on stimulation with synthetic oligodinucleotides containing the CpG-motif were studied. Peripheral blood CD4+ T-cell phenotype and activation status were evaluated by flow cytometry at 0, 2, and 8 weeks after treatment for expression of CD69, CD62L, chemokine receptors (CCR4, CXCR3, and CCR5), and intracellular cytokines (TNF-alpha, IFN-gamma, and IL-10). All patients experienced a positive clinical response to IFN-alpha treatment. There was no significant difference between patients and control subjects in the number of circulating pDCs, but there was a significant decrease in the capability of patients' pDCs to produce IFN-alpha in response to CpG (P < 0.001). Peripheral blood CD4+ T cells expressed reduced levels of surface CD62L (P < 0.005) as a measure of activation and higher levels of chemokine receptors CXCR3, CCR4, and CCR5 (P < 0.005, P < 0.05, and P < 0.05, respectively); in addition, intracellular T-cell IL-10 levels were increased once the treatment was initiated (P < 0.01). The data suggest that IFN-alpha may control uveitis by promoting induction of IL-10-producing T-cells, possibly T-regulatory cells. Dysregulation of the T-cell population in patients with uveitis may be associated with a defect in the pDCs' ability to produce IFN-alpha, which can be circumvented with administration of exogenous IFN-alpha.

Interferon α and CPG oligodeoxynucleotides elicit additive immunostimulatory and antitumor effects

We hypothesized that interferon alpha (IFN-alpha) and unmethylated cytosine-phosphothioate-guanine (CpG)-rich oligodexoynucleotides (CpG ODNs) would elicit potent antitumor activity due to the ability of this treatment combination to activate complimentary signal transduction intermediates. Peripheral blood mononuclear cells treated with CpG ODNs, IFN-alpha, or both agents combined were evaluated for cytotoxicity against human melanoma cells, Jak-STAT signal transduction by flow cytometry, and ISG-15 gene expression by real-time polymerase chain reaction. The effects of CpG ODNs and IFN-alpha were evaluated in murine models of melanoma in wild-type, IFN-gamma-deficient, and STAT1-deficient mice. Negative controls in all experiments included treatment with control ODN or phosphate-buffered saline. Treatment of peripheral blood mononuclear cells with a combination of CpG ODNs and IFN-alpha resulted in enhanced cytotoxicity, activation of natural killer cells, IFN-alpha-induced STAT1 phosphorylation, and transcription levels of ISG-15. These immunostimulatory effects of CpG ODNs were associated with increased expression of STAT1 and STAT2 proteins. Administration of CpG ODNs plus IFN-alpha elicited superior antitumor activity in a murine model of B16 melanoma compared with either agent alone. The antitumor properties of CpG ODNs were dependent on STAT1-mediated signal transduction within the host but independent of endogenously produced IFN-gamma. CpG ODNs represent potent immune stimulants that elicit antitumor effects through STAT1-mediated signal transduction.

Suppression of Cell Proliferation by Interferon-Alpha through Interleukin-1 Production in Adult Rat Dentate Gyrus

The therapeutic use of interferon-alpha (IFN-alpha), a proinflammatory cytokine, is known to cause various neuropsychiatric adverse effects. In particular, depression occurs in 30-45% of patients, frequently interrupting treatment. IFN-alpha-treated animals also show depression-like behaviors. However, mechanisms underlying the depression caused by IFN-alpha remain to be defined. Recently, a decrease in adult hippocampal neurogenesis was revealed as a possible neuropathological mechanism of depression. Therefore, we investigated the effect of subchronic IFN-alpha treatment on neurogenesis in the adult rat dentate gyrus (DG). Immediately after the administration of IFN-alpha for 1 week, a decrease in the number of 5-bromo-deoxyuridine-labeled proliferating cells was observed in the DG; however, no effect was detected on the expression of mature neuronal phenotype in the newly formed cells 3 weeks later. Also, an increase in the level of interleukin-1beta (IL-1beta), a major proinflammatory cytokine, was observed in the hippocampus following the administration of IFN-alpha. Furthermore, coadministration of an IL-1 receptor antagonist completely blocked the IFN-alpha-induced suppression of the cell-proliferative activity in the DG. Our results indicate that IFN-alpha suppresses neurogenesis in the DG, and that IL-1beta plays an essential role in the suppression. The decreased cell proliferation caused by IFN-alpha-induced IL-1beta may be responsible, at least in part, for IFN-alpha-induced depression.

Autologous tumor cell vaccination with PF-3512676 (CPG 7909) and GM-CSF followed by subcutaneous PF-3512676 and IFN-alpha for patients with metastatic renal cell carcinoma

2530 Background: Metastatic renal cell carcinoma (RCC) has a poor prognosis with a 5-year survival of less than 10%. Non-specific immunotherapy, e.g. IL-2 and IFN-α achieves responses in 10–30% of patients at the cost of relatively high toxicity. Tumor vaccination has shown great promise in a variety of cancers, particularly in the adjuvant setting. Studies in metastatic setting are suitable to identify the best adjuvants and to optimize vaccination schedules. CpGs are synthetic oligonucleotides that have been shown to have superior immunogenicity in animal and human vaccination studies (Hepatitis B). Besides its positive effect on the specific immune response, CpGs also stimulate the innate immune system. We initiated a phase I/II trial to investigate the potentials of CpG in the treatment of metastatic RCC. Methods: Nephrectomized patients with progressive metastatic RCC were vaccinated with autologous tumor cells (ATC) derived from the primary tumor or metastases. Vaccines consisted of irradiated ATC, PF-3512676 and GM-CSF. The first three induction vaccinations were given weekly followed by subcutaneous administration of IFN-α (6 MIU, TIW) and PF-3512676 (8 mg bi-weekly). After 3 months tumor evaluation was performed and in case of a remission or stable disease patients continued with 3 monthly vaccinations and PF-3512676 /IFN-α. Blood was collected for immunomonitoring and DTH responses against ATC were measured before and after vaccination. Results: Preparation of vaccines was successful in 88% of the patients. Twelve patients were included and treated according to the protocol. Treatment was well tolerated. At the vaccination site we observed erythema and induration. Some patients experienced flu-like symptoms, including fever and fatigue. In all patients we observed only after vaccination a DTH response (&gt; 10 mm) against ATC, suggestive for a specific antitumor response. Three patients (25%) achieved a partial response (durations 6, 4+, 4+ months) and 2 patients (17%) stable disease (3 months). Conclusions: This new combined immunotherapy is tolerable, safe, and immunogenic. Moreover, it can produce tumor responses in advanced RCC. No significant financial relationships to disclose.

Perioperative immunomodulation with interferon-alpha in patients with renal cell carcinoma: Early results of a controlled phase II trial

14525 Background: Complex perioperative immunodysfunction occurs in patients with renal cell carcinoma undergoing surgery. Earlier, we presented evidence of a survival benefit in patients, who received perioperative immunomodulation with interleukin-2 (JCO 23 (16S):4601, 2005). Here, we report on the effect of interferon-alpha (IFN-α). Methods: Fifty-four consecutive patients, who underwent tumor nephrectomy, were enrolled into this prospective one stage phase II trial from June 2003 to May 2005. Patients were alternately assigned to the two study groups: 27 received immunomodulation with IFN-α (4 doses 9 million IU s.c a week before operation, followed by a daily dose of 3 million IU until a day before the operation), 27 did not. Parameters of immunity (differential blood count, CD3, CD4, CD8, CD16, CD19, CD28, CD56, HLA-DR, VEGF, IL-10) were measured in venous blood before and during IFN-α, one day before and immediately after the operation, and on the 1., 3., 5., and 10. postoperative day. The primary endpoint was tumor-specific survival. T-test, χ2-test and the log-rank test were used for statistical analysis. Results: The study groups did not differ with respect to age, sex, tumor stage and grade, histological type, operation time and technique. IFN-α related toxicity was WHO grade 0 (11%), 1 (59%), 2 (26%), and 3 (4%). During IFN-α administration leukocytes, CD19, HLA-DR and VEGF dropped significantly, while no difference was observed in T-cell and NK-cell markers, and IL-10. All patients showed postoperatively elevated leukocyte counts. T-cell and activation markers decreased, but CD3, CD4 and CD28 alterations were significantly less accentuated in patients who had been treated with IFN-α. Median follow-up was 14 months. The 1- and 2-year rates (±SE) of tumor-specific survival were 96% (±4%) and 83% (±12%) in the IFN-α group and 85% (±7%) and 85% (±7%) in the control group, respectively (p = 0.52). Also, no difference was seen in progression-free survival (p = 0.32). Conclusions: In this study with limited follow-up, perioperative IFN-α medication was not associated with a survival benefit, but was well tolerated. Interestingly, the decline in VEGF during administration suggests a role of IFN-α in the inhibition of angiogenesis. No significant financial relationships to disclose.

Dynamics of CD81 expression on lymphocyte subsets during interferon-α-based antiviral treatment of patients with chronic hepatitis C

CD81 is a hepatitis C virus (HCV) coreceptor with important functions in lymphocytes. During treatment, CD81 expression may be changed directly by the antiviral therapy or indirectly by reduction of the HCV serum level. The regulation of CD81 on lymphocyte subtypes has not been investigated so far and may be relevant for the control of viral infection and treatment response. CD81 was analyzed by flow cytometry in CD8(+), CD4(+), CD19(+), and CD56(+) lymphocyte subtypes from 20 patients with chronic hepatitis C before, during, and after antiviral treatment with pegylated interferon-alpha (IFN-alpha) and ribavirin. A sustained virologic response (SVR) was achieved in 11 patients. Dynamics of CD81 were investigated in correlation with HCV-RNA dynamics and the outcome of therapy. During treatment, the following typical patterns of CD81 regulation were observed: down-regulation on CD8(+) T cells (P = 0.022) and most significantly, on CD56(+) natural killer cells (P < 0.001), transient up-regulation on CD19(+) B cells (P = 0.006), and weak and late down-regulation on CD4(+) T cells (P = 0.028). During treatment, CD81 expression was not associated with the HCV-RNA serum level on all lymphocyte subtypes. After end of treatment, CD81 increased again in CD8(+) and CD56(+) cells (P = 0.001, P = 0.002). On CD8(+) T cells post-treatment, CD81 remained lower in patients who achieved a SVR compared with patients who failed to eliminate HCV after treatment (P = 0.033). Lymphocyte subsets show different patterns of CD81 response before and during antiviral treatment, which are associated with administration of IFN-alpha and antiviral response.

Treatment of interferon-α for chronic hepatitis C

Combination therapy with polyethylene glycosylated IFN-α2a or IFN-α2b and ribavirin is currently the standard therapy for chronic hepatitis C. However, even with this therapy, hepatitis C virus cannot be eradicated in 50% of patients with refractory chronic hepatitis C. In addition, withdrawal or dose reduction occurs in ∼ 40% of patients due to adverse effects. This treatment is also a contraindication in some patients, such as in patients with coexisting diseases or in elderly patients. For these patients, standard IFN-α monotherapy is even safer and more effective. In patients with chronic hepatitis C, IFN-α monotherapy results in a significant increase in the cumulative survival rate by suppressing the progression to hepatocellular carcinoma or liver failure. In addition, other efficacious therapeutic regimens have been employed, such as prolonged administration of standard IFN-α in elderly patients; prolonged low-dose continuous administration in patients with decompensated cirrhosis or hepatocellular carcinoma postoperative patients; and combination therapy with 5-fluorouracil and standard IFN-α for advanced hepatocellular carcinoma. Monotherapy with standard IFN-α should thus be recognised as one of the important therapeutic strategies for chronic hepatitis C.

Biodefense Shield and Avian Influenza

To the Editor: In defending against avian influenza virus H5N1, the possibility of adopting treatments being developed for biodefense should not be overlooked. Biodefense medicine primarily concerns respiratory infections because bioweapons in their deadliest form disperse Bacillus anthracis and Yersinia pestis, the causes of anthrax and plague, and highly contagious viruses like smallpox, Ebola, and Marburg as aerosols. The National Institutes of Health and Department of Defense have funded developing novel biodefense medications designed to stimulate innate mucosal immunity by using interferons (IFNs) and interferon inducers. We suggest that studies begin immediately to explore the potential of IFNs to prevent infections and reduce deaths caused by avian influenza viruses in animal models and humans. Modulating innate mucosal immunity is promising as a rapid-acting, broad-spectrum approach to combat bioterrorism (1). Innate immunity, the initial response to a pathogen, is potentially capable of eradicating infection. Even when the innate immune response cannot eliminate a virus, it may substantially reduce viral load, reduce pathology, facilitate clearing of the virus by the adaptive immune response, and slow the spread of infection (1). As biodefense medications, IFNs and IFN-inducers are under development for aerosolized delivery to the lungs (2,3). Conventional IFN administration by injection often results in low concentrations at target sites and high concentrations in circulation, which may cause serious side effects. Aerosolized delivery minimizes side effects and produces more rapid clinical responses. Inhaled IFNs have proven to be well tolerated and beneficial for rhinovirus infection (4) and pulmonary tuberculosis (5). Medications being developed to prevent infections caused by viral bioweapons and other diseases include 1) Oral IFN-α or Alferon low dose oral (LDO) (Hemispherx Biopharma, Inc., Philadelphia, PA, USA); 2) inhalable IFN-γ (InterMune, Brisbane, CA, USA); 3) dsRNA [Poly (ICLC)] or Ampligen (Hemispherx Biopharma, Inc.); 4) ssRNA (Aldara and Resiquimod from 3M Pharmaceuticals, St. Paul, MN, USA); and 5) CpG7909 and {type:entrez-protein,attrs:{text:CpG10101,term_id:899319225,term_text:CPG10101}}CpG10101 oligonucleotides (Coley Pharmaceutical Group, Wellesley, MA, USA) (2). These drugs have either been approved by the Food and Drug Administration (FDA) (Aldara), are in clinical trials (Alferon LDO, inhalable IFN-γ, Resiquimod, CPG7909, and {type:entrez-protein,attrs:{text:CpG10101,term_id:899319225,term_text:CPG10101}}CpG10101), or at a preclinical stage of development (Ampligen). Aldara is approved for genital warts, actinic keratoses, and basal cell carcinoma. Others drugs are being tested for aerosolized delivery to modulate mucosal immunity of the respiratory tract. All could be expeditiously tested with inhalational or intranasal administration in H5N1 models with mice, ferrets, pigs, and monkeys. IFN-α and IFN-γ work by binding their receptors and activating downstream antiviral pathways involving the dsRNA-dependent protein kinase (PKR), the 2´, 5´ oligoadenylate synthetase/RNase L, or the MxA protein. dsRNA, ssRNA, and CpG oligonucleotides are ligands for toll-like receptors (TLRs) and modulate antiviral immunity through TLR signaling pathways and IFN induction (2). At the cellular level inside the lungs, these drugs will enhance phagocytotic and cytolytic activity in alveolar macrophages. Once infection is established, H5N1 resists the antiviral effects of IFNs and tumor necrosis factor-α (6). Resistance is associated with the nonstructural gene of H5N1 and may be 1 mechanism for H5N1's extraordinary virulence. Therefore, prophylactic use of IFNs and IFN-inducers is critical to combat H5N1. They may also be effective if administered immediately after infection. IFN resistance also exists for other viral infections. For instance, poxviruses including vaccinia virus encode 2 proteins that interfere with RNaseL and PKR pathways and 2 soluble IFN receptors that interfere with IFN-induced antiviral pathways. Nevertheless, at least in animal models, pre-infection administration of exogenous IFN can reduce deaths and poxvirus viral load. In mice, intranasal administration of IFN-α and IFN-γ prevents lethal vaccinia infection (3). IFN-α, IFN-γ, and an IFN inducer, Poly (ICLC), protect mice infected with H1N1 influenza virus (7). Hence, we suggest that anti-H5N1 prophylaxis by IFN-stimulated innate mucosal immunity is a promising therapy worth immediate investigation in animal models. A second mechanism proposed to explain H5N1 virulence is also IFN related. This is the storm, as shown by elevated levels of proinflammatory cytokines including IFNs found in 2 patients who died of H5N1 infections (8). Cytokine storms can result in autoimmune reactions, tissue damage, or septic shock. High IFN doses for long periods may exacerbate autoimmunity. However, despite similar cytokine storms (9), some severe acute respiratory syndrome patients respond well to IFN therapy (10). Optimal formulation and regimen of IFN administration could be crucial to effective anti-H5N1 prophylaxis. In the interests of safety, we propose that initial prophylaxis studies use relatively low IFN doses for short periods (≈1–2 weeks). It is unlikely that all of these drugs will effectively protect against H5N1. And a drug that is effective might not work for everyone; genetic polymorphism influences IFN response. However, FDA approval of even one of them might save many lives.

Alterations of leptin during IFN-α therapy in patients with chronic viral hepatitis

Leptin has a particular profibrogenic role in the liver. We investigated whether IFN-alpha influences leptin production in patients with chronic hepatitis B (CHB) and C (CHC). Leptin was determined in serial samples from 63 CHB and 42 CHC IFN-alpha treated patients. Furthermore, we evaluated whether leptin alterations were associated with patients' characteristics. Sera were investigated at serial time-points using an enzyme-linked-immunosorbent-assay. Controls consisted of 36 patients with autoimmune liver diseases and 44 healthy patients. Leptin levels before IFN-alpha administration were higher in CHB and CHC compared to healthy (P<0.004) and diseased controls (P=0.0001). In CHB patients, we observed a significant reduction of leptin during IFN-alpha treatment and lasting for up to 6 months after the end of treatment, followed by an increase reaching pretreatment levels at 1.5 years after stopping therapy. The pattern of leptin alterations was similar in CHC patients where leptin's decrease was more pronounced at 6 months after the end of treatment. Biochemical or virological response to treatment was not associated with leptin reduction in both groups. This study provides information on leptin kinetics during IFN-alpha treatment and follow-up in CHB and CHC patients and suggests IFN-alpha as a potential inhibitor of leptin production.

Psychiatric Symptoms Induced by??Antiviral Therapy in Chronic??Hepatitis C

Interferon-alpha treatment is associated with a large number of adverse effects. Depressive symptoms are not unexpected, and potentially dangerous psychiatric adverse effects can induce life-threatening conditions. We compared the incidence of depressive symptoms in patients with chronic hepatitis C during treatment with pegylated interferon-alpha-2a (IFNalpha-2a) and pegylated interferon-alpha-2b (IFNalpha-2b). We randomly divided 186 subjects with chronic hepatitis C into two treatment groups: group A, treated with IFNalpha-2a, and group B, treated with IFNalpha-2b. Treatment was continued for up to 48 weeks. Liver biopsy and hepatitis C virus RNA assay were carried out in all patients. Depressive symptoms and the prevalence of psychiatric adverse effects during treatment with IFN were evaluated using the Hamilton Depression Rating Scale, the Zung Self-Rating Depression Scale, and the Structured Clinical Interview for Diagnostic and Statistic Manual-IV axis disorders. At baseline 53% of subjects in group A and 57% of subjects in group B presented with depressive symptoms; at 12 weeks we found a high incidence of depressive symptoms in both groups (group A 61% and group B 65%) and three cases of life-threatening psychiatric symptoms (i.e. psychosis and delirium requiring discontinuation of antiviral therapy and admission to a psychiatric unit) in group A. Long-term administration of IFN can be associated with serious psychiatric adverse effects. It is very important that psychiatric symptoms are diagnosed early in IFN treatment so to improve treatment compliance and prevent fatal and/or life-threatening adverse events, as were documented in some subjects treated with IFNalpha-2a in our study.

Histone deacetylase inhibitors modulate renal cell carcinoma sensitivity to TRAIL/Apo-2L-induced apoptosis by enhancing TRAIL-R2 expression

Every year, 12,000 people in the U.S. die from renal cell carcinoma. Current therapies include partial or complete nephrectomy or treatments such as administration of IFN-? and/or interleukins that are moderately effective, at best. Moreover, the current therapies are invasive and inefficient and new therapies are needed. Histone deacetylase (HDAC) inhibitors have recently been found to sensitize cells to apoptosis-inducing agents, although the mechanism of this action is largely unknown. The current study has investigated the potential of using five different histone deacetylase inhibitors (HDACI) (depsipeptide, MS-275, oxamflatin, sodium butyrate, and trichostatin A) to sensitize TNF-related apoptosis-inducing ligand (TRAIL)/Apo-2L-resistant renal cell carcinoma cells to TRAIL/Apo-2L-induced apoptosis. Sodium butyrate and trichostatin A each enhanced TRAIL/Apo-2L-mediated tumor cell death to a greater extent than the other HDACI. Annexin V staining and caspase activity demonstrated the mechanism of cell death was apoptosis. Both sodium butyrate and trichostatin A treatment also increased mRNA and surface expression of TRAIL receptor 2 that was dependent on the transcription factor Sp1, thus providing a possible mechanism behind the increased sensitivity to TRAIL/Apo-2L. These results indicate that combination therapy of HDACI, such as sodium butyrate and trichostatin A, and TRAIL/Apo-2L has great potential for an efficient alternative therapy for renal cell carcinoma.