Improved biological and transcriptional activity of monopegylated interferon-α-2a isomers

Porcine interferon-α linked to the porcine IgG-Fc induces prolonged and broad-spectrum antiviral effects against foot-and-mouth disease virus

Foot-and-mouth disease (FMD) is an economically important disease, and the FMD virus (FMDV) can spread rapidly in susceptible animals. FMD is usually controlled through vaccination. However, commercial FMD vaccines are only effective 4-7 days after vaccination. Furthermore, FMDV comprises seven serotypes and various topotypes, and these aspects should be considered when selecting a vaccine. Antiviral agents could provide rapid and broad protection against FMDV. Therefore, this study aimed to develop a fusion protein of consensus porcine interferon-α and Fc portion of porcine antibody IgG (poIFN-α-Fc) using a baculovirus expression system to develop a novel antiviral agent against FMDV. We measured the antiviral effects of the poIFN-α-Fc protein against FMDV and the enhanced duration in vitro and in vivo. The broad-spectrum antiviral effects were tested against seven FMDV serotypes, porcine reproductive and respiratory syndrome virus (PRRSV), and bovine enterovirus (BEV). Furthermore, the early protective effects and neutralizing antibody levels were tested by co-injecting poIFN-α-Fc and an FMD-inactivated vaccine into mice or pigs. Sustained antiviral effects in pig sera and mice were observed, and pigs injected with a combination of the poIFN-α-Fc and an inactivated FMD vaccine were protected against FMDV in a dose-dependent manner at 2- and 4-days post-vaccination. In addition, combined with the inactivated FMD vaccine, poIFN-α-Fc increased the neutralizing antibody levels in mice. Therefore, poIFN-α-Fc is a potential broad-spectrum antiviral and adjuvant candidate that can be used with inactivated FMD vaccines to protect pigs against FMDV.

Continuous sensing of IFNα by hepatic endothelial cells shapes a vascular antimetastatic barrier

Hepatic metastases are a poor prognostic factor of colorectal carcinoma (CRC) and new strategies to reduce the risk of liver CRC colonization are highly needed. Herein, we used mouse models of hepatic metastatization to demonstrate that the continuous infusion of therapeutic doses of interferon-alpha (IFNα) controls CRC invasion by acting on hepatic endothelial cells (HECs). Mechanistically, IFNα promoted the development of a vascular antimetastatic niche characterized by liver sinusoidal endothelial cells (LSECs) defenestration extracellular matrix and glycocalyx deposition, thus strengthening the liver vascular barrier impairing CRC trans-sinusoidal migration, without requiring a direct action on tumor cells, hepatic stellate cells, hepatocytes, or liver dendritic cells (DCs), Kupffer cells (KCs) and liver capsular macrophages (LCMs). Moreover, IFNα endowed LSECs with efficient cross-priming potential that, along with the early intravascular tumor burden reduction, supported the generation of antitumor CD8+ T cells and ultimately led to the establishment of a protective long-term memory T cell response. These findings provide a rationale for the use of continuous IFNα therapy in perioperative settings to reduce CRC metastatic spreading to the liver.

Population Pharmacokinetics of Ropeginterferon Alfa-2b: A Comparison Between Healthy Caucasian and Chinese Subjects

Objective: To develop a population pharmacokinetic (PK) model for ropeginterferon alfa-2b and to compare its PK properties between Caucasian and Chinese populations.

Methods: A population PK model was developed based on data from two phase I clinical trials conducted in Caucasian and Chinese individuals, to evaluate the influence of ethnicity on the PKs of ropeginterferon alfa-2b.

Results: We included 456 observations from 30 healthy Caucasian subjects and 438 observations from 27 healthy Chinese subjects in the population PK analysis. The PKs of ropeginterferon alfa-2b were best described by a one-compartment quasi-equilibrium approximated target-mediated drug disposition model with first-order absorption and absorption lag times. The typical value (relative standard error%) of apparent clearance (CL/F) and volume of distribution of ropeginterferon alfa-2b in 70-kg subjects were 0.778 (12%) L/day and 2.32 (14%) L, respectively. Body weight was the only significant factor affecting the CL/F. There were no obvious differences in the PK properties of ropeginterferon alfa-2b, and predicted steady-state exposure was similar in the Chinese and Caucasian populations.

Conclusion: No significant ethnic differences in ropeginterferon alfa-2b PKs were observed between the Chinese and Caucasian populations.

Effect of different interferonα2 preparations on IP10 and ET-1 release from human lung cells

Background

Alfa-interferons (IFNα2a, IFNα2b, 40KDa-PEGIFNα2a and 12KDa-PEGIFNα2b) are effective treatments for chronic hepatitis C infection. However, their usage has been associated with a variety of adverse events, including interstitial pneumonitis and pulmonary arterial hypertension. Although rare, these adverse events can be severe and potentially life-threatening, emphasizing the need for simple biomarkers of IFN-induced lung toxicity.

Methods

Human lung microvascular endothelial cells (HLMVEC), human pulmonary artery smooth muscle (HPASM) cells and A549 cells were grown under standard conditions and plated into 96- or 6-well plates. Cells were stimulated with various concentrations of different IFNs in hydrocortisone-free medium. After 24 and 48 hours, IP10 and ET-1 were measured by ELISA in conditioned medium. In a second set of experiments, cells were pre-treated with tumour necrosis factor-α (TNF-α) (10 ng/mL).

Results

IFNα2a, IFNα2b, 40KDa-PEGIFNα2a and 12KDa-PEGIFNα2b, but not IFNλ, induced IP10 (CXCL10) release and increased IP10 gene induction in HLMVEC. In addition, all four IFNα preparations induced IP10 release from HPASM cells and A549 cells pre-treated with TNFα. In each of these cell types, 40KDa-PEGIFNα2a was significantly less active than the native forms of IFNα2a, IFNα2b or 12KDa-PEGIFNα2b. Similarly, IFNα2a, IFNα2b and 12KDa-PEGIFNα2b, but not 40KDa-PEGIFNα2a, induced endothelin (ET)-1 release from HPASM cells.

Conclusions

Consistent with other interstitial pulmonary diseases, both IP10 and ET1 may serve as markers to monitor IFN-induced lung toxicity in patients. In addition, both markers may also serve to help characterize the risk associated with IFNα preparations to induce lung toxicity.

Designing transient binding drugs: a new concept for drug discovery

A multitude of weak, or transient, biological interactions (dissociation constant: K(d)>microM), either working alone or in concert, occur frequently throughout biological systems. We are starting to appreciate their importance in complex biological networks. This realization has important implications to drug discovery as we can question the current paradigm of drug design to find the highest possible binders (drugs) to a given target (receptor). Development of transient drugs, defined by their binding to target, can be based on high-off-rates, multivalent approaches or multiple targets. Now, techniques are available to discover such drug candidates. The greatest problem yet to overcome is probably the mind-set of the individual researcher that weak binders are undesired and therefore of no benefit.

Antiproliferative activity of the human IFN-alpha-inducible protein IFI44

The interferon-alpha (IFN-alpha)-inducible protein IFI44 is associated with hepatitis C virus (HCV) infection, and its function is unknown. We show here in two human melanoma cell lines (ME15 and D10) that transcription starts 4 h after induction, and peak protein levels are reached 24 h after stimulation. We show by immunofluorescence, viral overexpression, and cellular fractionation that IFI44 is a cytoplasmic protein. Overexpression of IFI44 cDNA induces an antiproliferative state in vitro, even in cells that are not responsive to IFN-alpha. IFI44 contains a perfect GTP binding site but has no homology to known GTPases or G proteins. Based on these results, we propose a model in which IFI44 binds intracellular GTP, and this depletion abolishes extracellular signal-regulated kinase (ERK) signaling and results finally in cell cycle arrest.

Interferons alpha and lambda inhibit hepatitis C virus replication with distinct signal transduction and gene regulation kinetics

BACKGROUND & AIMS

Hepatitis C virus (HCV) is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma. Current therapy with pegylated interferon alpha (IFN-alpha) in combination with ribavirin is associated with adverse effects and often fails to induce a sustained response. IFN-lambdas, recently discovered IFN gene family members, exhibit antiviral and cell stimulatory activities similar to IFN-alpha. We aimed to determine whether IFN-lambda exhibits antiviral activity toward HCV and to compare the signal transduction and effector gene pathways with those of IFN-alpha.

METHODS

Using the HCV replicon system and cell culture infectious reporter virus, we compared IFN-alpha and IFN-lambda effects on HCV RNA replication and protein expression, as measured by quantitative reverse-transcriptase polymerase chain reaction, luciferase expression, and Western blot. Receptor expression and signaling pathways were explored using flow cytometry and Western blot. IFN-alpha- and IFN-lambda-mediated gene expression changes were compared using microarray analyses.

RESULTS

IFN-lambda exhibited dose- and time-dependent HCV inhibition, independent of types I and II IFN receptors. The kinetics of IFN-lambda-mediated signal transducers and activators of transcription (STAT) activation and induction of potential effector genes were distinct from those of IFN-alpha. IFN-lambda induced steady increases in levels of known interferon stimulated genes (ISGs), whereas IFN-alpha ISGs peaked early and declined rapidly. IFN-lambda inhibited replication of HCV genotypes 1 and 2 and enhanced the antiviral efficacy of subsaturating levels of IFN-alpha.

CONCLUSIONS

These results demonstrate distinct differences in IFN-lambda- and IFN-alpha-induced antiviral states. Understanding these differences may prove useful for developing new HCV treatment strategies.

Survey of the year 2003 commercial optical biosensor literature

In the year 2003 there was a 17% increase in the number of publications citing work performed using optical biosensor technology compared with the previous year. We collated the 962 total papers for 2003, identified the geographical regions where the work was performed, highlighted the instrument types on which it was carried out, and segregated the papers by biological system. In this overview, we spotlight 13 papers that should be on everyone's 'must read' list for 2003 and provide examples of how to identify and interpret high-quality biosensor data. Although we still find that the literature is replete with poorly performed experiments, over-interpreted results and a general lack of understanding of data analysis, we are optimistic that these shortcomings will be addressed as biosensor technology continues to mature.