Mouse Type-I Interferon-Mannosylated Albumin Fusion Protein for the Treatment of Chronic Hepatitis.

Although a lot of effort has been put into creating drugs and combination therapies against chronic hepatitis, no effective treatment has been established. Type-I interferon is a promising therapeutic for chronic hepatitis due to its excellent anti-inflammatory effects through interferon receptors on hepatic macrophages. To develop a type-I IFN equipped with the ability to target hepatic macrophages through the macrophage mannose receptor, the present study designed a mouse type-I interferon-mannosylated albumin fusion protein using site-specific mutagenesis and albumin fusion technology. This fusion protein exhibited the induction of anti-inflammatory molecules, such as IL-10, IL-1Ra, and PD-1, in RAW264.7 cells, or hepatoprotective effects on carbon tetrachloride-induced chronic hepatitis mice. As expected, such biological and hepatoprotective actions were significantly superior to those of human fusion proteins. Furthermore, the repeated administration of mouse fusion protein to carbon tetrachloride-induced chronic hepatitis mice clearly suppressed the area of liver fibrosis and hepatic hydroxyproline contents, not only with a reduction in the levels of inflammatory cytokine (TNF-α) and fibrosis-related genes (TGF-ß, Fibronectin, Snail, and Collagen 1α2), but also with a shift in the hepatic macrophage phenotype from inflammatory to anti-inflammatory. Therefore, type-I interferon-mannosylated albumin fusion protein has the potential as a new therapeutic agent for chronic hepatitis.

Development of Kupffer cell targeting type-I interferon for the treatment of hepatitis via inducing anti-inflammatory and immunomodulatory actions.

Because of its multifaceted anti-inflammatory and immunomodulatory effects, delivering type-I interferon to Kupffer cells has the potential to function as a novel type of therapy for the treatment of various types of hepatitis. We report herein on the preparation of a Kupffer cell targeting type-I interferon, an albumin-IFNα2b fusion protein that contains highly mannosylated N-linked oligosaccharide chains, Man-HSA(D494N)-IFNα2b, attached by combining albumin fusion technology and site-directed mutagenesis. The presence of this unique oligosaccharide permits the protein to be efficiently, rapidly and preferentially distributed to Kupffer cells. Likewise IFNα2b, Man-HSA(D494N)-IFNα2b caused a significant induction in the mRNA levels of IL-10, IL-1Ra, PD-L1 in RAW264.7 cells and mouse isolated Kupffer cells, and these inductions were largely inhibited by blocking the interferon receptor. These data indicate that Man-HSA(D494N)-IFNα2b retained the biological activities of type-I interferon. Man-HSA(D494N)-IFNα2b significantly inhibited liver injury in Concanavalin A (Con-A)-induced hepatitis model mice, and consequently improved their survival rate. Moreover, the post-administration of Man-HSA(D494N)-IFNα2b at 2 h after the Con-A challenge also exerted hepato-protective effects. In conclusion, this proof-of-concept study demonstrates the therapeutic effectiveness and utility of Kupffer cell targeting type-I interferon against hepatitis via its anti-inflammatory and immunomodulatory actions.

Design and tuning of a cell-penetrating albumin derivative as a versatile nanovehicle for intracellular drug delivery.

Human serum albumin (HSA) is a superior carrier for delivering extracellular drugs. However, the development of a cell-penetrating HSA remains a great challenge due to its low membrane permeability. We report herein on the design of a series of palmitoyl-poly-arginine peptides (CPPs) and an evaluation of their cell-penetrating effects after forming a complex with HSA for use in intracellular drug delivery. The palmitoyl CPPs forms a stable complex with HSA by anchoring itself to the high affinity palmitate binding sites of HSA. Among the CPPs evaluated, a cyclic polypeptide composed of D-dodecaarginines, palmitoyl-cyclic-(D-Arg)12 was the most effective for facilitating the cellular uptake of HSA by HeLa cells. Such a superior cell-penetrating capability is primarily mediated by macropinocytosis. The effect of the CPP on pharmacological activity was examined using three drugs loaded in HSA via three different methods: a) an HSA-paclitaxel complex, b) an HSA-doxorubicin covalent conjugate and c) an HSA-thioredoxin fusion protein. The results showed that cell-penetrating efficiency was increased with a corresponding and significant enhancement in pharmacological activity. In conclusion, palmitoyl-cyclic-(D-Arg)12/HSA is a versatile cell-penetrating drug delivery system with great potential for use as a nano-carrier for a wide diversity of pharmaceutical applications.

Changing paradigm of prophylaxis with longer acting factor concentrates.

Beginning in the 1960s the care of persons with haemophilia began to improve dramatically through a series of transformative improvements in care: development of lyophilized factor concentrates, home care programmes, prophylaxis and (due to the tragedy of HIV/hepatitis) the development of virally safer plasma-derived and recombinant factor concentrates. Prophylaxis, if commenced early and given in sufficient dose/frequency has been shown to allow persons with haemophilia to maintain excellent joints and lead normal lives. Yet the relatively short half-lives of factor (F) VIII and IX concentrates leads to the need for frequent venous access. This remains a significant burden for patients with haemophilia on prophylaxis causing in many cases reduced patient adherence to prophylaxis and negative longterm outcomes. The last 5 years have witnessed a flourish of new bioengineered longer acting FVIII and IX concentrates manufactured using different technologies (pegylation or fusion to Fc/albumin). These products (especially the longer acting FIX concentrates) are likely to have profound implications on prophylaxis. With these longer acting factor concentrates prophylaxis regimens will almost certainly change. This will involve changes in what trough levels are targeted and how frequently factor is administered. It is hoped that these changes may improve patients' adherence to prophylaxis and their quality of life. These long-acting factor concentrates will undoubtedly have cost repercussions and will raise important questions regarding how decisions about choosing one longer acting concentrate over another, and whether these products are interchangeable, are made. This article will review what changes may ensue with the advent of these new longer acting factor concentrates.

Challenges for new haemophilia products from a manufacturer's perspective.

The development of new and improved therapeutic options for the management of haemophilia is a great challenge for both physicians and manufacturers. After factor VIII concentrates became widely available, progress in medicine and advances in biotechnology led to the development of virus-inactivated, plasma-derived products of high purity and recombinant products, which are currently further improved regarding an extended half-life, potentially allowing for effective prophylaxis with reduced dosing frequency and hopefully less immunogenicity. This article describes some of the challenges that were experienced by the manufacturer during the development of the high-purity, plasma-derived factor VIII concentrate, Beriate® P, which, after implementation of a nanofiltration step in its manufacture, is now designated as Beriate®; it also outlines the challenges and achievements to date with half-life extended products such as the recombinant fusion proteins linking coagulation factor VIIa (rVIIa-FP) and factor IX (rIX-FP) with albumin.