IFN-κ is a recently identified type I IFN that exhibits both structural and functional homology with the other type I IFN subclasses. In this study, we have investigated the effect of IFN-κ on cells of the innate immune system by comparing cytokine release following treatment of human cells with either IFN-κ or two recombinant IFN subtypes, IFN-β and IFN-α2a. Although IFN-α2a failed to stimulate monocyte cytokine secretion, IFN-κ, like IFN-β, induced the release of several cytokines from both monocytes and dendritic cells, without the requirement of a costimulatory signal. IFN-κ was particularly effective in inhibiting inducible IL-12 release from monocytes. Unlike IFN-β, IFN-κ did not induce release of IFN-γ by PBL. Expression of the IFN-κ mRNA was observed in resting dendritic cells and monocytes, and it was up-regulated by IFN-γ stimulation in monocytes, while IFN-β mRNA was minimally detectable under the same conditions. Monocyte and dendritic cell expression of IFN-κ was also confirmed in vivo in chronic lesions of psoriasis vulgaris and atopic dermatitis. Finally, biosensor-based binding kinetic analysis revealed that IFN-κ, like IFN-β, binds strongly to heparin (Kd: 2.1 nM), suggesting that the cytokine can be retained close to the local site of production. The pattern of cytokines induced by IFN-κ in monocytes, coupled with the unique induction of IFN-κ mRNA by IFN-γ, indicates a potential role for IFN-κ in the regulation of immune cell functions.

The long half-life and stability of human serum albumin (HSA) make it an attractive candidate for fusion to short-lived therapeutic proteins. Albuferon (Human Genome Sciences [HGS], Inc., Rockville, MD) beta is a novel recombinant protein derived from a gene fusion of interferon-beta (IFN-beta ) and HSA. In vitro, Albuferon beta displays antiviral and antiproliferative activities and triggers the IFN-stimulated response element (ISRE) signal transduction pathway. Array analysis of 5694 independent genes in Daudi-treated cells revealed that Albuferon beta and IFN-beta induce the expression of an identical set of 30 genes, including 9 previously not identified. In rhesus monkeys administered a dose of 50 microg/kg intravenously (i.v.) or subcutaneously (s.c.) or 300 microg/kg s.c., Albuferon beta demonstrated favorable pharmacokinetic properties. Subcutaneous bioavailability was 87%, plasma clearance at 4.7-5.7 ml/h/kg was approximately 140-fold lower than that of IFN-beta, and the terminal half-life was 36-40 h compared with 8 h for IFN-beta. Importantly, Albuferon beta induced sustained increases in serum neopterin levels and 2',5' mRNA expression. At a molar dose equivalent to one-half the dose of IFN-beta, Albuferon beta elicited comparable neopterin responses and significantly higher 2',5'-OAS mRNA levels in rhesus monkeys. The enhanced in vivo pharmacologic properties of IFN-beta when fused to serum albumin suggest a clinical opportunity for improved IFN-beta therapy.

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A UV spectrophotometric and RP-HPLC method for the Naringenin quantification in the developed solid dispersions is described. Both the methods were validated according to ICH Q2 R (1) guidelines for linearity, accuracy, precision, limit of detection, limit of quantification, specificity and robustness. HPLC was run in isocratic mode on a reversed-phase C18 column (250 × 4.6 mm internal diameter and particle size of 5 μm) with methanol:water (70:30, v/v) as the mobile phase maintaining a flow rate of 1.0 ml/min. Naringenin showed an absorbance maximum (λ max) at 288 nm which was used for the UV spectrophotometric determinations. The calibration curve of Naringenin showed linearity in the required concentration range (R 2 > 0.999) by both the UV and HPLC methods. Both the methods were found to be precise and accurate with recovery range of 98-101% and relative standard deviation < 2%. Most importantly, the accuracy and precision achieved by the HPLC method, correlated closely with the UV method. Current study also involves detection and quantification of Naringenin released from its formulations by both the developed methods. This paper demonstrates the high correlation (R 2 ≥ 0.98) between the UV and HPLC methods when determining the release of Naringenin from various formulations. With this established correlation, we hereby suggest that, for routine analysis, UV spectroscopy can be an economic, simple, reliable and less time-consuming alternative for expensive and time-consuming chromatographic analysis.

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