Suitability of an automated nucleic acid extractor (easyMAG) for use with hepatitis C virus and human immunodeficiency virus type 1 nucleic acid amplification testing.

Serological screening assays have greatly reduced, but not eliminated, the risk of transmission of viral infections by transfusion of blood and blood products. In addition, the 1999 regulation of the European Agency for the Evaluation of Medicinal Products requiring all plasma for fractionation to have tested negative for hepatitis C virus (HCV) RNA (CPMP/BWP/390/97, 1998) led many blood transfusion services to introduce nucleic acid amplification technology (NAT) to screen blood donations for HCV, and in some services for human immunodeficiency virus (HIV) and hepatitis B virus (HBV). BioMérieux's second-generation system, the NucliSENS easyMAG, was evaluated as a suitable platform for the automated extraction of nucleic acids for use with the existing SNBTS NAT assays.

Vaccination with an inactivated virulent feline immunodeficiency virus engineered to express high levels of Env.

An inactivated virus vaccine was prepared from a pathogenic isolate of feline immunodeficiency virus containing a mutation that eliminated an endocytic sorting signal in the envelope glycoprotein, increasing its expression on virions. Cats immunized with inactivated preparations of this modified virus exhibited strong titers of antibody to Env by enzyme-linked immunosorbent assay. Evidence of protection following challenge demonstrated the potential of this approach to lentiviral vaccination.

Evolution of replication efficiency following infection with a molecularly cloned feline immunodeficiency virus of low virulence.

The development of an effective vaccine against human immunodeficiency virus is considered to be the most practicable means of controlling the advancing global AIDS epidemic. Studies with the domestic cat have demonstrated that vaccinal immunity to infection can be induced against feline immunodeficiency virus (FIV); however, protection is largely restricted to laboratory strains of FIV and does not extend to primary strains of the virus. We compared the pathogenicity of two prototypic vaccine challenge strains of FIV derived from molecular clones; the laboratory strain PET(F14) and the primary strain GL8(414).

Demonstration of biological activity of CD40 ligand (CD154) in the domestic cat.

The interaction between CD40L (CD154) on T cells and CD40 on antigen-presenting cells induces expression of accessory molecules that facilitate immune activation. Therefore, CD40L may have utility as an adjuvant for the development of potent antigen-specific immune responses following vaccination. As there was no information about the feline homologue of CD40L or its function, we generated stable cell lines expressing cDNAs encoding the feline CD40L homologue.

Vaccination with inactivated virus but not viral DNA reduces virus load following challenge with a heterologous and virulent isolate of feline immunodeficiency virus.

It has been shown that cats can be protected against infection with the prototypic Petaluma strain of feline immunodeficiency virus (FIV(PET)) using vaccines based on either inactivated virus particles or replication-defective proviral DNA. However, the utility of such vaccines in the field is uncertain, given the absence of consistent protection against antigenically distinct strains and the concern that the Petaluma strain may be an unrepresentative, attenuated isolate. Since reduction of viral pathogenicity and dissemination may be useful outcomes of vaccination, even in the absence of complete protection, we tested whether either of these vaccine strategies ameliorates the early course of infection following challenge with heterologous and more virulent isolates.