Generation of a parvovirus B19 vaccine candidate.

Parvovirus B19 is the causative agent of fifth disease in children, aplastic crisis in those with blood dyscrasias, and hydrops fetalis. Previous parvovirus B19 virus-like-particle (VLP) vaccine candidates were produced by co-infection of insect cells with two baculoviruses, one expressing wild-type VP1 and the other expressing VP2. In humans, the VLPs were immunogenic but reactogenic.

Induction of broad CD4+ and CD8+ T-cell responses and cross-neutralizing antibodies against hepatitis C virus by vaccination with Th1-adjuvanted polypeptides followed by defective alphaviral particles expressing envelope glycoproteins gpE1 and gpE2 and nonstructural proteins 3, 4, and 5.

Broad, multispecific CD4(+) and CD8(+) T-cell responses to the hepatitis C virus (HCV), as well as virus-cross-neutralizing antibodies, are associated with recovery from acute infection and may also be associated in chronic HCV patients with a favorable response to antiviral treatment. In order to recapitulate all of these responses in an ideal vaccine regimen, we have explored the use of recombinant HCV polypeptides combined with various Th1-type adjuvants and replication-defective alphaviral particles encoding HCV proteins in various prime/boost modalities in BALB/c mice. Defective chimeric alphaviral particles derived from the Sindbis and Venezuelan equine encephalitis viruses encoding either the HCV envelope glycoprotein gpE1/gpE2 heterodimer (E1E2) or nonstructural proteins 3, 4, and 5 (NS345) elicited strong CD8(+) T-cell responses but low CD4(+) T helper responses to these HCV gene products.

Characterization of prion protein (PrP)-derived peptides that discriminate full-length PrPSc from PrPC.

On our initial discovery that prion protein (PrP)-derived peptides were capable of capturing the pathogenic prion protein (PrP(Sc)), we have been interested in how these peptides interact with PrP(Sc). After screening peptides from the entire human PrP sequence, we found two peptides (PrP(19-30) and PrP(100-111)) capable of binding full-length PrP(Sc) in plasma, a medium containing a complex mixture of other proteins including a vast excess of the normal prion protein (PrP(C)). The limit of detection for captured PrP(Sc) was calculated to be 8 amol from a approximately 10(5)-fold dilution of 10% (wt/vol) human variant Creutzfeldt-Jakob disease brain homogenate, with >3,800-fold binding specificity to PrP(Sc) over PrP(C).

Hepatitis C virus polyprotein vaccine formulations capable of inducing broad antibody and cellular immune responses.

Although approximately 3 % of the world's population is infected with Hepatitis C virus (HCV), there is no prophylactic vaccine available. This study reports the design, cloning and purification of a single polyprotein comprising the HCV core protein and non-structural proteins NS3, NS4a, NS4b, NS5a and NS5b. The immunogenicity of this polyprotein, which was formulated in alum, oil-in-water emulsion MF59 or poly(dl-lactide co-glycolide) in the presence or absence of CpG adjuvant, was then determined in a murine model for induction of B- and T-cell responses.

Design of novel conformational and genotype-specific antigens for improving sensitivity of immunoassays for hepatitis C virus-specific antibodies.

The current commercially licensed enzyme-linked immunosorbent assays (ELISAs) for hepatitis C virus (HCV) mainly use recombinant proteins containing linear epitopes. There is evidence, however, that conformational epitopes of HCV are more immunoreactive. Thus, we have designed an HCV antibody assay that employs a conformational protein, NS3NS4a PI (with functional protease and helicase activities), and a linear fusion protein, multiple-epitope fusion antigen 7.

Assessment of the target-capture PCR hepatitis B virus (HBV) DNA quantitative assay and comparison with commercial HBV DNA quantitative assays.

Recent clinical studies suggest that hepatitis B virus (HBV) load and genotype may be independent predictors of responses to antiviral therapies. However, it is difficult for clinicians to accurately determine viral loads in patient samples because results--both the values and the units of measure--can vary greatly among different tests. Accordingly, the World Health Organization (WHO) has produced the first international standard for HBV DNA for nucleic acid amplification technology (NAT) assays.

Induction of broad and potent anti-human immunodeficiency virus immune responses in rhesus macaques by priming with a DNA vaccine and boosting with protein-adsorbed polylactide coglycolide microparticles.

Several vaccine technologies were evaluated for their abilities to induce anti-human immunodeficiency virus Gag immune responses in rhesus macaques. While no vaccine alone was able to induce broad and strong immune responses, these were achieved by priming with Gag DNA and boosting with Gag protein adsorbed to polylactide coglycolide microparticles. This regimen elicited strong antibodies, helper T cells, and cytotoxic T lymphocytes and thus holds promise as an effective vaccination scheme.