Cathelicidin antimicrobial peptide LL-37 augments interferon-ß expression and antiviral activity induced by double-stranded RNA in keratinocytes.

BACKGROUND: Cathelicidin antimicrobial peptide LL-37 has the capacity to kill a wide range of microbes and to modify host immunity. Recently, our group observed that the activation of keratinocytes by LL-37 and DNA greatly increases interferon (IFN)-ß through Toll-like receptor (TLR)9. However, the effect of LL-37 on the induction of IFN-ß through TLR3, a sensor of double-stranded (ds) RNA, in keratinocytes is not well known. OBJECTIVES: To investigate whether LL-37 could affect TLR3 signalling and antiviral activity in normal human epidermal keratinocytes (NHEKs). METHODS: We investigated the production of IFN-ß in NHEKs stimulated with a TLR3 ligand, poly (I:C), in the presence of LL-37. To examine the effect of LL-37 and poly (I:C) on antiviral activity, a virus plaque assay using herpes simplex (HS) virus type-1 was carried out. The uptake of poly (I:C) conjugated with fluorescein isothiocyanate (FITC) into the keratinocytes was observed in the presence of LL-37. Immunostaining for TLR3 and LL-37 was performed using skin samples from HS. RESULTS: LL-37 and poly (I:C) synergistically induced the expression of IFN-ß in NHEKs. Furthermore, co-stimulation with LL-37 and poly (I:C) significantly decreased the viral plaque numbers compared with poly (I:C) or LL-37 alone. LL-37 enhanced the uptake of FITC-conjugated poly (I:C) into cells. Immunohistochemical analysis demonstrated that the expression of TLR3 and LL-37 is upregulated in HS lesions. CONCLUSIONS: Our findings suggest that LL-37 augments the antiviral activity induced by dsRNA in keratinocytes, which may contribute to the innate immune response to cutaneous viral infections such as HS.

CD27 costimulation contributes substantially to the expansion of functional memory CD8(+) T cells after peptide immunization.

Naive T cells require signals from multiple costimulatory receptors to acquire full effector function and differentiate to long-lived memory cells. The costimulatory receptor, CD27, is essential for optimal T-cell priming and memory differentiation in a variety of settings, although whether CD27 is similarly required during memory CD8(+) T-cell reactivation remains controversial. We have used OVA and anti-CD40 to establish a memory CD8(+) T-cell population and report here that their secondary expansion, driven by peptide and anti-CD40, polyI:C, or LPS, requires CD27. Furthermore, antigenic peptide and a soluble form of the CD27 ligand, CD70 (soluble recombinant CD70 (sCD70)), is sufficient for secondary memory CD8(+) T-cell accumulation at multiple anatomical sites, dependent on CD80/86. Prior to boost, resting effector- and central-memory CD8(+) T cells both expressed CD27 with greater expression on central memory cells. Nonetheless, both populations upregulated CD27 after TCR engagement and accumulated in proportion after boosting with Ag and sCD70. Mechanistically, sCD70 increased the frequency of divided and cytolytic memory T cells, conferred resistance to apoptosis and enabled retardation of tumor growth in vivo. These data demonstrate the central role played by CD27/70 during secondary CD8(+) T-cell activation to a peptide Ag, and identify sCD70 as an immunotherapeutic adjuvant for antitumor immunity.

[Cycloferon: mechanism of action, functions and application].

In recent years, both interferons and inductors of endogenous interferon production find increasing use in clinical practice. The latter agents are characterized by high antiviral and immunomodulatory activity in the absence of serious side effects, which makes it possible to prescribe long courses if necessary. One of the most frequently used interferon inductors is cycloferon. Diverse effects of cycloferon on biochemical and cellular cascades (including induction of alpha- and beta-interferon, inhibition ofproapoptotic factors such as tumor necrosis factor and interleukin 1-beta) suggest that it also takes active part in the regulation of apoptosis, one of the most important processes of cell activity that opens up new prospects for the therapeutic use of cycloferon.

[Influence of сycloferon on the сytokine blood profile and production of proinflammatory сytokines in the cultures of mononucleares of peripheral blood of the patients with chronic tonsillitis].

The 88 patients with chronic tonsillitis (CT) was investigated. The 46 patients (basic group) got the modern immunoactive preparation cycloferon and 42 patients (comparison group) - only the generally accepted therapy. During immunological researches on a background clinical manifestation of СT the increase proinflammatory cytokines (CK) (TNFα, IL-1Β) in the serum, and also increase the level of spontaneous products of these CK in the cultures mononucleares of periferal blood was detected. At general accepted treatment took place increase level proinflammatory CK at serum on background decline stimulated product of CK at mononucleares cultures. Aрplication of cycloferon at the treatment of CT provided to normalization cytokines profile of the blood and production of CK in the cultures mononucleares.

[Dose-dependent interferon-induction activity and pharmacokinetics of cycloferon in healthy humans].

Dose-dependent interferonogenic activity and pharmacokinetics of cycloferon--a low-molecular inductor of interferon--have been studied in a group of 35 healthy volunteers. It is established that cycloferon induces the production of early alpha-IFN within 24 h from the moment of drug introduction. In a dose of 500 mg, the drug induces production of gamma-IFN by leukocytes in vitro within 24 h from the moment of introduction, with retention of the titer for 48 h. This proves the need for differentiated approach to a choice of the dose of cycloferon, depending on diseases in which complex treatment involving interferon inductors is required. After the introduction of cycloferon (500 mg) in healthy volunteers, the peak of drug concentration in the blood is observed in 40 min, with the subsequent considerable decrease within 2 h. Variation of the cycloferon concentration in the blood correlates with its content in urine, which is evidence for the drug elimination from organism through kidneys.

Discovery of a highly potent series of TLR7 agonists.

The discovery of a series of highly potent and novel TLR7 agonist interferon inducers is described. Structure-activity relationships are presented, along with pharmacokinetic studies of a lead molecule from this series of N9-pyridylmethyl-8-oxo-3-deazapurine analogues. A rationale for the very high potency observed is offered. An investigation of the clearance mechanism of this class of compounds in rat was carried out, resulting in aldehyde oxidase mediated oxidation being identified as a key component of the high clearance observed. A possible solution to this problem is discussed.

Randomised clinical trial: anti-viral activity of ANA773, an oral inducer of endogenous interferons acting via TLR7, in chronic HCV.

BACKGROUND: The ANA773 is an oral prodrug of a small-molecule toll-like receptor (TLR)7 agonist. Preclinical and healthy volunteer clinical studies with ANA773 have demonstrated induction of endogenous interferon-α (IFN-α) of multiple subtypes, which supports the potential utility in the treatment of chronic hepatitis C virus (HCV) infection. AIM: To examine safety, tolerability, pharmacodynamics, pharmacokinetics and anti-viral activity of ANA773. METHODS: The ANA773 was investigated in a double-blind, placebo-controlled study in 34 patients chronically infected with HCV of any genotype. Patients were treatment-naïve or had relapsed following previous interferon-based treatment. This dose escalation study was composed of four dose groups (800, 1200, 1600 and 2000mg). In each group, six to eight patients received ANA773 and two received placebo. Patients were dosed with ANA773 every-other-day for either 28 days (800, 1200 or 1600mg) or 10days (2000mg). RESULTS: Mild to moderate adverse events were reported, with an increase in frequency and intensity with increasing dose. No serious AEs were reported and there were no early discontinuations. There were dose-related increases in various markers of IFN-α response. The mean maximum change in serum HCV RNA level from baseline was -0.34, -0.29, -0.40, -0.97 and -1.26log(10) in the placebo, 800, 1200, 1600 and 2000mg cohorts, respectively. At the 2000mg dose, ANA773 significantly (P=0.037) reduced serum HCV RNA levels (range: 0.14 to -3.10log(10) ). CONCLUSION: The ANA773 was generally well tolerated and resulted in a dose-related IFN-dependent response leading to a significant decrease in serum HCV RNA levels in the 2000mg dose group.

Pharmacokinetics and safety of imiquimod 5% cream in the treatment of molluscum contagiosum in children.

Imiquimod cream 5%, a toll-like receptor 7 agonist, induces alpha-interferon upon topical application, prompting off-label usage to treat children with molluscum contagiosum. We conducted an open-label study to measure serum drug concentration in children aged 2-12 years with extensive molluscum contagiosum (> or = 10% total body surface area). Dependent on extent of subject disease and weight, one to three packets (12.5 mg imiquimod per packet) were applied per dose, three times per week for 4 weeks. Serum imiquimod and metabolite concentrations were measured at pre dose and 2, 4, and 8 hours postdose 1 and dose 12. Thirty children were screened; 22 children (64% boys; 91% white; mean age 6.2 +/- 2.87 years; median involved body area treated 13.5%) were enrolled. Peak serum imiquimod concentrations following single and multiple dosing were low (< 10 ng/mL). Imiquimod concentrations increased 2- to 3.5-fold with multiple dosing. After single and multiple dosing, peak serum imiquimod (Pearson correlation r = 0.4989 and 0.7219, p < 0.05 both, respectively) and area under the serum concentration-time curve values (r = 0.4989 and 0.7219, p < 0.05 both, respectively) correlated with dose normalized for body weight (mg/kg). Systemic drug levels were low after single and multiple doses of imiquimod 5% cream in children.

Determination of arbidol in human plasma by LC-ESI-MS.

A sensitive, specific and accurate method for determination of arbidol in human plasma was developed. Arbidol and internal standard were extracted from plasma samples by liquid-liquid extraction with diethyl ether. The chromatographic separation was accomplished on a Shiseido C18 3 microm analytical column (100 mm x 2.0 mm i.d.) at a flow rate of 0.3 mL/min isocratically. Detection was performed on a single quadrupole mass spectrometer by selected ion monitoring (SIM) mode via electrospray ionization (ESI) source. The method had a chromatographic run time of 6 min and a good linear relationship over the range 1-1000 ng/mL. The limit of quantitation for arbidol in plasma was 1 ng/mL. The intra-day and inter-day precision (R.S.D.%) was lower than 7% and accuracy ranged from 95 to 105%. The proposed method enables unambiguous identification and quantification of arbidol in vivo and has been successfully applied to study the pharmacokinetics of arbidol in healthy male Chinese volunteers.

Pharmacokinetics of a synthetic interferon inducer amixin in mice.

Pharmacokinetics of amixin, a synthetic interferon inducer, has been studied in mice under intravenous and oral routes of administration. Following oral administration, 80% of the drug was eliminated in the unchanged form. Its absolute biological availability comprised 0.7. In comparison to oral administration, after intravenous injection concentrations of amixin and its radioactive metabolites were higher during the first 5-120 min of the experiment in all organs and tissues. During the first 4-24 h, we observed an increase in the total radioactive material that was similar for both modes of administration. Low drug elimination rate was noted under both conditions. A novel integral model-independent method for estimation of equilibrium tissue-to-plasma partition ratios (K(p) has been proposed. The suggested integral parameter K(p) does not depend on the structure of the kinetic scheme and, most importantly, could be used for analysis of incomplete kinetic curves. We also propose a combined model that could help determine parameters of irreversible xenobiotic binding, the extent of the absorption from the intestine and relative efficacy of the hepatic excretion, in particular presystemic drug elimination.

Use of magnetic resonance imaging to assess blood-brain/blood-glioma barrier opening during conformal radiotherapy.

PURPOSE: For chemotherapy to act synergistically and safely with radiation against high-grade gliomas, drugs must pass the endothelial junctions of the blood-tumor barrier (BTB) to reach all tumor cells, and should not pass the blood-brain barrier (BBB) to cause toxicity to normal brain. The objective of this study was to assess BBB/BTB status using magnetic resonance imaging (MRI) during a course of radiotherapy of high-grade gliomas. PATIENTS AND METHODS: Sixteen patients with grade 3 or 4 supratentorial malignant glioma receiving conformal radiotherapy (RT) underwent contrast-enhanced MRI before, during, and after completion of RT. A gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) uptake index was analyzed with respect to the tumor and RT dose received. RESULTS: In the nonenhanced tumor region, contrast uptake increased significantly after the receipt of approximately 10 Gy (P < .01), and reached a maximum after the receipt of approximately 30 Gy. In the initially contrast-enhanced tumor region, contrast uptake decreased over the course of RT and became significant after completion of RT in patients without progressive disease. The healthy brain showed only nonsignificant changes during and after irradiation. CONCLUSION: Contrast MRI reveals increases in Gd-DTPA uptake in the initially nonenhanced tumor region but not in the remaining brain during the course of RT, suggesting opening of the BTB. This finding suggests that the effect of conformal radiation is more selective on the BTB than the BBB, and there may be a window extending from 1 week after the initiation of radiotherapy to 1 month after the completion of treatment during which a pharmaceutical agent has maximum access to high-grade gliomas.

Prodrugs of 9-benzyl-8-hydroxy-2-(2-hydroxyethylthio)adenine: potent interferon inducing agents in monkeys.

In order to improve the oral bioavailability of 9-benzyl-8-hydroxy-2-(2-hydroxyethylthio)adenine (SM-295072), a potent interferon (IFN) inducing agent, we synthesized prodrugs of it by utilizing the hydroxy groups at the C(2)-side chain and/or the C(8)-position. The carbonate prodrug at the C(8)-position was more effective than that at the C(2)-side chain for oral absorption in rats. Among the compounds prepared, compound 6 demonstrated the most preferable prodrug properties, and the maximum plasma concentration of 6 was approximately 4-fold higher than that of SM-295072. Furthermore, compound 6 was dose-dependently absorbed in monkeys by oral administration, and exhibited a potent IFN-inducting activity that correlated well with its plasma drug concentration.

Pharmacokinetic properties, induction of interferon, and efficacy of selected 5-halo-6-phenyl pyrimidinones, bropirimine analogues, in a model of severe experimental autoimmune encephalomyelitis.

We showed previously that a 5-halo-6-phenyl-pyrimidinone, bropirimine (PNU-54461), inhibited progression of severe experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis. In the work presented here, we examined the activity of a group of chemically-related bropirimine analogues. First, the pharmacokinetic properties of the bropirimine analogues were examined in normal mice following oral dosing. After equal oral doses, both PNU-56169 and PNU-63693 were found in the blood of normal mice at equal or higher concentrations than bropirimine, but PNU-54462 and PNU-56359 were present in blood only at very low concentrations. Next, we examined the bropirimine analogues for activity in our model of severe EAE. At a dose of 400 mg/kg administered orally every second day PNU-56169 nearly completely blocked EAE progression, but was ineffective at 100 mg/kg. PNU-63693 was effective in EAE at concentrations of 200 mg/kg, 100 mg/kg, 50 mg/kg, and as low as 25 mg/kg. Histopathology was examined by observing leukocyte infiltration into the lower spinal cords of the mice. Treatment with 400 mg/kg of PNU-56169 and doses of 25, 50, 100, and 200 mg/kg of PNU-63693 significantly inhibited leukocyte infiltration into the lower spinal cord of treated mice in a dose-dependent manner. Orally administered PNU-56169 and PNU-63693 also stimulated significant concentrations of IFNalpha in the serum of treated mice, which may be related to the efficacy of the compounds in EAE. However, the correlation between IFNalpha in the blood and efficacy in treating EAE was not exact. Thus, PNU-56169 and PNU-63693 were delivered to the blood following oral dosing, induced significant concentrations of IFNalpha in the blood, and were equally or more potent than PNU-54461 in inhibiting clinical signs of EAE. The results suggest that 5-halo-6-phenyl-pyrimidinones are an interesting class of compounds to investigate for development in the treatment of multiple sclerosis.

Assay of bropirimine in rat plasma by means of robotic solid-phase extraction and high-performance liquid chromatography.

A rapid and simple high-performance liquid chromatography (HPLC) method incorporating automated solid-phase extraction (SPE) is described for the determination of bropirimine, 2-amino-5-bromo-6-phenyl-4(3H)-pyrimidinone, in plasma samples from various species. Using an automated sample processor, plasma samples were loaded onto C18 SPE columns and the drug eluted with ethanol-methylene chloride (10:90, v/v). The extracts were analyzed by reversed-phase HPLC using a C8 column with a mobile phase consisting of acetonitrile-water-trifluoroacetic acid (20:80:0.1, v/v/v). The UV absorbance of the column effluent was monitored at a wavelength of 292 nm. Linear calibration curves were obtained in the range of 0.01 to 22 micrograms/ml. Precision (< or = 4% relative standard deviation) and accuracy (< or = 5% error) were acceptable at the concentrations evaluated. Application of this method to the quantitation of bropirimine in rat plasma for a toxicokinetic/bioavailability study is reported.

[Bropirimine (U-54461S) phase I clinical studies].

Bropirimine (U-54461S), an oral interferon (IFN) inducer that has also a direct antiproliferative activity, is a novel antitumor agent. To investigate the safety and pharmacokinetics of bropirimine tablets and to measure IFN concentrations in patients with cancer, Phase I studies were conducted. In single dose study (0.25 to 3g) and multiple-dose study with one-day dosing (1 or 2g, every one or two hours, three times a day), bropirimine treatment was well tolerated by the patients with cancer. In multiple-dose study with consecutive days dosing (1 or 2g, every 2 hours, three times a day for 3 or 5 consecutive days), a regimen with a dose of 1g orally administered every two hours, three times a day for three consecutive days was considered to be tolerable to cancer patients. Adverse drug reactions frequently observed were generalized malaise, fever, nausea/vomiting, anorexia, headache/dull headache, and tachycardia. Abnormalities in laboratory tests frequently observed were leukemia, neutropenia, thrombocytopenia, and elevation in GOT/GPT. IFN was not induced in any patients in the single dose study. It was, however, induced in 3 of 16 cases (18.8%) in the one-day dosing study and in 6 of 7 cases (85.7%) in the consecutive days dosing study. As to clinical antitumor efficacy, a decrease in size of the tumor lesions and improvement in subjective/objective symptoms were noted in two cases in the one-day dosing study. With these findings, the regimen with the dose of 1g orally administered every two hours, three times a day for three consecutive days with a four-day drug-free interval per week was recommended for early phase II studies.

Pharmacokinetics of germanium after po beta-carboxyethylgermanium sesquioxide in 24 Chinese volunteers.

AIM: To compare the pharmacokinetics after po different doses of beta-carboxyethylgermanium sesquioxide (Ge-132). METHODS: An atomic absorption spectrophotometric system was used to measure germanium concentrations in plasma and urine samples after po Ge-132 1 (low dose, LD), 2.5 (medium dose, MD), and 4 (high dose, HD) g.m-2 in 24 healthy volunteers (one dose per 8 subjects). RESULTS: T1/2 alpha (LD, 1.2 +/- 0.7 h; MD, 1.1 +/- 0.6 h; HD, 1.2 +/- 0.5 h), T1/2 beta (LD, 5.2 +/- 1.2 h; MD, 5.8 +/- 2.5 h; HD, 5.5 +/- 1.4 h) and Cl/F (LD, 33 +/- 12 L.h-1; MD, 35 +/- 10 L.h-1; HD, 33 +/- 11 L.h-1) were not dose-related. Tmax was between 0.75 h and 2 h. Cmax (LD, 5.3 +/- 2.2 mg.L-1; MD, 13 +/- 5 mg.L-1; HD 18 +/- 8 mg.L-1, HD) and AUC (LD, 31 +/- 13 mg.h.L-1; MD, 60 +/- 16 mg.h.L-1; HD, 79 +/- 42 mg.h.L-1) were positive correlation to the dose of Ge-132. Urine-eliminated germanium within 24 h accounted for 11 +/- 3% of LD, 9 +/- 3% of MD, and 6 +/- 5% of HD (calculated from Ge/F) and showed a negative correlation to the dose. CONCLUSION: 1) Intracorporal process of Ge after po Ge-132 coincided with the first-order absorption and elimination with two-compartment kinetic model; 2) The amount of germanium eliminated in urine was below 11%.

[Drug kinetics in soft contact lenses. I. In vitro studies]. / Kinetika lekarstvennykh preparatov v miagkikh kontaktnykh linzakh. Soobshchenie I. Issledovanie in vitro.

The in vitro kinetics (specifically, absorption and desorption) of drugs belonging to various pharmacological groups (atropine sulfate, gentamicin sulfate, dexamethasone, lecozyme, and poludan) in soft contact lenses (low-hydrophilic with 40% aqueous content and highly hydrophilic with 74% aqueous content. 0.2 and 0.7 mm thick) was studied by radiometry, as were the effects of chemical structure of a drug, hydrophilic properties and thickness of soft contact lenses, and temperature of solution on these processes.

[Pharmacokinetics of the interferon inducer PHL-6 and interferon synthesis in target organs under various methods of drug administration]. / Farmakokinetika induktora interferona PKhL-6 i sintez interferona v organakh-misheniiakh pri razlichnykh sposobakh ego vvedeniia.

The pharmacokinetics of PHL-6 and interferon synthesis dynamic in the target organs (tissues) of mice were studied during its and intraperitoneal administration. In the experimental setting, there was a direct correlation between the interferon production in the murine organs with single PHL-6 and distribution of 14C PHL-6. The highest radioactivity with its oral administration was detected in the liver and intestine. Interferon was actively synthesized in the intestine, liver and serum, showing the levels of 20000, 1024-2048 and 512-1024 IU/ml, respectively. The prolonged action of the drug was in good agreement with the low PHL-6 excretion from the body. It was also shown that almost the whole radiation dose 1 (greater than 98%) was excreted with feces and urine after single and chronic administrations of uniformly labeled PHL-6 which proved important clinical drug use.