A potent, long-lasting form of interferon alpha-2a mono-pegylated with a 40 kilodalton branched poly(ethylene glycol) was designed, synthesized, and characterized. Mono-pegylated interferon alpha-2a was comprised of four major positional isomers involving Lys31, Lys121, Lys131, and Lys134 of interferon. The in vitro anti-viral activity of pegylated interferon alpha-2a was found to be only 7% of the original activity. In contrast, the in vivo antitumor activity was severalfold enhanced compared to interferon alpha-2a. Pegylated interferon alpha-2a showed no immunogenicity in mice. After subcutaneous injection of pegylated interferon alpha-2a, a 70-fold increase in serum half-life and a 50-fold increase in mean plasma residence time concomitant with sustained serum concentrations were observed relative to interferon alpha-2a. These preclinical results suggest a significantly enhanced human pharmacological profile for pegylated interferon alpha-2a. Results of Phase II/III hepatitis C clinical trials in humans confirmed the superior efficacy of pegylated interferon alpha-2a compared to unmodified interferon alpha-2a.

Interferon stimulates the expression of a number of genes encoding enzymes with antiviral activities, including myxovirus resistance-1 (MxA), 2-5-oligoadenylate synthetase 1 (OAS-1) and double-stranded RNA-dependent protein kinase (PKR). We examined whether polymorphisms in these genes influenced the outcome of hepatitis C virus (HCV) infection. We observed a lower frequency of the GG genotype at position À88 in the MxA gene promoter in self-limiting HCV infection (OR ¼ 0.56; 95% CI: 0.35-0.8; P ¼ 0.010) and in nonresponders to therapy (OR ¼ 0.49; 95% CI: 0.25-0.95; P ¼ 0.020). This genotype predominantly influenced the outcome of treatment in patients with viral genotype 1 (OR ¼ 0.22 95% CI: 0.07-0.67; P ¼ 0.002). A polymorphism in the 3 0 -untranslated region of the OAS-1 gene was associated with outcome of infection (GG genotype less frequent in self-limiting infection: OR ¼ 0.43; 95% CI: 0.21-0.86; P ¼ 0.010). A polymorphism at position À168 in the promoter region of the PKR gene was associated with self-limiting infection (CT genotype: OR ¼ 2.75; 95% CI: 1.45-5.24; P ¼ 0.002). Further associations were found with a CGG trinucleotide repeat in the 5 0 UTR region of the PKR gene. Polymorphisms in the interferon-induced genes, MxA, OAS-1 and PKR appear thus associated with HCV outcome.

The intermediate filament proteins vimentin, desmin, and glial fibrillary acidic protein are cleaved in vitro by human immunodeficiency virus type 1 protease (HIV-1 PR). Microsequencing showed that HIV-1 PR cleaved both human and murine vimentin between leucine-422 and arginine-423 within the sequence between positions 418 and 427, Ser-SerLeu-Asn-Leu/Arg-Glu-Thr-Asn-Leu (SSLNL/RETNL). Minor cleavages at other sites were also observed. Heat-denatured vimentin was cleaved by HIV-1 PR less efficiently than native vimentin. A decapeptide containing the sequence SSLN-LRETNL was also cleaved in vitro by HIV-1 PR as predicted. The presence of a charged residue (arginine) at the primary cleavage site distinguishes this from other known naturally occurring cleavage sites. Microinjection of HIV-1 PR into cultured human fibroblasts resulted in a 9-fold increase in the percentage of cells with an altered and abnormal distribution of vimentin intermediate filaments. Most commonly, the intermediate filaments collapsed into a clump with ajuxtanuclear localization. These results support the possibility that intermediate filament proteins may serve as substrates within HIV-1-infected cells.

The results of this study provide compelling evidence for the existence of the gene or genes controlling optimal T-B-cell cooperative interactions in the designated I region of the H-2 gene complex. Previously, we have speculated that the relevant gene(s) involved may well be located in this region based on several observations from our earlier work in this area (3, 5, 6). Thus, in the preceding paper, we showed that T and B cells from B10.BR and A strain mice developed effective cooperative interactions in vitro to DNP-KLH in a system identical to the one reported herein. Since these mice differ for genes in the S and D regions of H-2 but are identical for K and I region genes, we were able to localize the critical genes to the K-end of H-2.

Persistent hepatitis B virus infection is a major risk factor for hepatocellular carcinoma, the most frequent cancer in some developing countries. Up to 95% of those infected at birth and 15% of those infected after the neonatal period fail to clear hepatitis B virus, together resulting in Ϸ350 million persistent carriers worldwide. Via a whole genome scan in Gambian families, we have identified a major susceptibility locus as a cluster of class II cytokine receptor genes on chromosome 21q22. Coding changes in two of these genes, the type I IFN receptor gene, IFN-AR2, and the IL-10RB gene that encodes a receptor chain for IL-10-related cytokines including the IFN-s, are associated with viral clearance (haplotype P value ‫؍‬ 0.0003), and in vitro assays support functional roles for these variants in receptor signaling.complex trait ͉ IL-10 ͉ interferon ͉ susceptibility ͉ virus T here are Ϸ350 million people with persistent hepatitis B virus (HBV) infection worldwide. Of these infected people, up to one-quarter will die from complications of the infection including cirrhosis and primary liver cancer. However, infection with HBV does not invariably lead to chronic hepatitis: When infection is acquired during childhood, as is normally the case in subSaharan Africa, up to 90% will eliminate the virus spontaneously. When infection is acquired during the early neonatal period from an HBV-infected mother, only 10% of children will eliminate the virus, but this situation, known as vertical transmission, is rare in Africa.Susceptibility to persistent infection is governed by a number of factors, in addition to the age at infection. Twin studies and limited genetic association study data indicate that host genetic background influences the outcome of infection (1). It is likely that genetic susceptibility to persistent HBV infection is polygenic, and that both MHC and non-MHC genes are involved (2).Current treatment for persistent HBV infection is partially effective, expensive, and impractical in developing countries where persistent HBV infection rates are at their highest (3). It is therefore crucial to identify factors that determine whether HBV becomes a self-limiting or persistent infection because these factors may reveal new therapeutic opportunities for patients with chronic HBV infection. This study was conducted to identify genetic determinants of persistent HBV infection by using a genomewide approach. ResultsTo search for major loci that might have some effect on viral persistence in a highly endemic area, 318 microsatellites were analyzed in 88 independent affected sibling pairs (ASPs) in 61 Gambian families. The most significant evidence of linkage was found on chromosome 21 [logarithm of odds (lod) ϭ 1.66; P ϭ 0.003] (Table 1, which is published as supporting information on the PNAS web site). This locus on chromosome 21 also showed evidence of linkage when a total of 31 markers (with SIBPAIR P value Ͻ0.1) were followed up in a further 106 independent ASPs in 74 families (D21S1252 screens 1 and 2 combined: ...