No abstract

An assay to measure avidity index (AI) was developed to diagnose incident hepatitis C virus (HCV) infections. The assay demonstrated an AI value statistically significantly lower in primary HCV infections than in chronic infections. When the assay was applied to past resolved infections, the difference in AI values was not as significant as the difference between incident and chronic infections. Lower AI values obtained in past resolved infections may be directly related to lower levels of immunoglobulin G anti-HCV in past resolved infections than in either new infections or chronic infections.

The new HEV EIA developed in the present study is a highly specific diagnostic assay for the detection of anti-HEV activity in serum specimens obtained from different epidemiologic settings.

At temperatures from (289 to 353) K, the ternary system (ethene + water + 2-propanol) is known to exhibit a region of liquid−liquid−vapor (L1L2V) equilibria at elevated pressures that is bordered by the lower ((L1 = L2)V) and upper (L1(L2 = V)) critical end point lines. This particular demixing effect is commonly known as “salting out by a supercritical gas”. In this work, the effect of adding different electrolytes on the pressure of both critical end points at (293 and 333) K is investigated.

In spite of extensive research, no effective vaccine against hepatitis C virus (HCV) has been devel oped so far. DNA immunization is a potent technique of vaccine design strongly promoting the cellular arm of immune response. The genes encoding nonstructural HCV proteins (NS2-NS5B) are promising candi dates for vaccine development. NS5A is a protein involved in viral pathogenesis, in the induction of immune response, and probably in viral resistance to interferon treatment. The objective of this study was to construct a DNA vaccine encoding NS5A protein and evaluate its immunogenicity. A plasmid encoding a full size NS5A protein was produced using the pcDNA3.1 (+) vector for eukaryotic expression system. The expression of the NS5A gene was confirmed by immunoperoxidase staining of the transfected eukaryotic cells with anti NS5A monoclonal antibodies. Triple immunization of mice with the plasmid vaccine induced a pronounced cellular immune response against a broad spectrum of NS5A epitopes as assessed by T cell proliferation and secretion of antiviral cytokines IFN γ and IL 2. In T cell stimulation in vitro experiments, NS5A derived antigens were modeled by synthetic peptides, recombinant proteins of various genotypes, and phages carrying exposed NS5A peptides. A novel immunomodulator Immunomax showed high adjuvant activity in DNA immunization. The data obtained indicate that the suggested DNA construct has a strong potential in the development of the gene vaccines against hepatitis C.