Lentivirus Vaccine Development: Antigen presentation by Salmonella and iscom

Human immunodeficiency virus types 1 and 2 (HIV-I and HIV-2), the causative agents of acquired immune deficiency syndrome (AIDS) in humans, are members of the Lentivirinae subfamily of the Retroviridae family. The lentivirus subfamily also includes related members from other species, like monkeys (simian immunodeficiency viruses [SIV]), cats (feline immunodeficiency viruses [FIV]), and the ungulates sheep, goats, horses and cattle. Mature lentiviruses are spherical to ellipsoid particles with a diameter of approximately 100 nm consisting of a lipid envelope surrounding a cone shaped core (Gelderblom et al 1989) (Fig. I). In HIV-I the core is formed by a 24 kd capsid protein (p24). It contains two identical strands of positive-sense genomic RNA closely associated with the nucleocapsid proteins (p7 and p9) and several copies of the reverse transcriptase. A membrane associated matrix protein p 17 is situated between the core and the envelope. In the envelope a 41 kd transmembrane glycoprotein (gp41) is anchored. The transmembrane protein is non-covalently attached to the 120 kd surface glycoprotein (gpI20). The other lentiviruses have a similar structure, with slightly different molecular weights of their proteins

Construction and evaluation of an expression vector allowing the stable expression of foreign antigens in a Salmonella typhimurium vaccine strain at toxic levels.

Salmonella strains have great potential as live carriers of heterologous antigens to induce immunity against a variety of infectious diseases. However, the amount of heterologous antigen required to induce an adequate immune response may be toxic for the bacterium and result in cell death, overattenuation or loss of expression of the heterologous antigen. To solve this problem an expression vector was developed with a strong promoter located on a DNA fragment which is inverted at random. Antigen is only expressed in one particular orientation of the promoter. Thus a bacterial population harbouring the plasmid will consist o

Enhancement of feline immunodeficiency virus infection after immunization with envelope glycoprotein subunit vaccines.

Cats were immunized three times with different recombinant feline immunodeficiency virus (FIV) candidate vaccines. Recombinant vaccinia virus (rVV)-expressed envelope glycoprotein with (vGR657) or without (vGR657 x 15) the cleavage site and an FIV envelope bacterial fusion protein (beta-Galactosidase-Env) were incorporated into immune-stimulating complexes or adjuvanted with Quil A. Although all immunized cats developed antibodies against the envelope protein, only the cats vaccinated with the rVV-expressed envelope glycoproteins developed antibodies which neutralized FIV infection of Crandell feline kidney cells. These antibodies failed to neutralize infection of thymocytes with a molecularly cloned homologous FIV. After the third immunization the cats were challenged with homologous FIV. Two weeks after challenge the cell-associated viral load proved to be significantly higher in the cats immunized with vGR657 and vGR657 x 15 than in the other cats. The cats immunized with vGR657 and vGR657 x 15 also developed antibodies against the Gag proteins more rapidly than the cats immunized with beta-Galactosidase-Env or the control cats. This suggested that immunization with rVV-expressed glycoprotein of FIV results in enhanced infectivity of FIV. It was shown that the observed enhancement could be transferred to naive cats with plasma collected at the day of challenge

Induction of feline immunodeficiency virus specific antibodies in cats with an attenuated Salmonella strain expressing the Gag protein.

Salmonella typhimurium aroA strains (SL3261), expressing high levels of the Gag protein of feline immunodeficiency virus (FIV) fused with maltose binding protein (SL3261-MFG), were constructed using an invertible promoter system that allows the stable expression of heterologous antigens at levels toxic for bacteria. A SL3261 strain expressing the B subunit of cholera toxin by a similar system (SL3261-CtxB) served as a control in FIV-immunization experiments. Cats immunized once orally or intraperitoneally with SL3261-MFG or SL3261-CtxB all developed serum antibodies to SL3261 lipopolysaccharide and against maltose binding protein or the B subunit of cholera toxin, respectively. Two intraperitoneal immunizations with SL3261-MFG also resulted in the development of Gag specific serum antibodies. Two oral immunizations with SL3261-MFG primed for a Gag specific response, which was demonstrated upon FIV challenge. All challenged cats became inf

Data from: Differential immunomodulation of porcine bone marrow derived dendritic cells by E. coli Nissle 1917 and β-glucans

This in vitro study assessed the immunomodulatory properties of yeast-derived β-glucans (MacroGard®) and the Gram-negative probiotic E. coli Nissle 1917 (EcN) using fresh and cryopreserved porcine BMDCs

Dataset underlying the publication 'Optimization of Capture ELISAs for Chicken Cytokines Using Commercially Available Antibodies''

The research is about optimization and validation of capture ELISA for chicken IL-2, IL-6, IL-10, IL-12p40, and IFN-y using commercially available antibodies and recombinant cytokines. To optimize antibody concentrations, checkerboard titration was performed. Then, validation tests for capture ELISAs were performed to assess lower limit of detection (LLOD), matrix effect, parallelism, and inter-assay variation.</p

Establishment and characterization of canine parvovirus-specific murine CD4+ T cell clones and their use for the delineation of T cell epitopes.

Canine parvovirus (CPV)-specific T cell clones were generated by culturing lymph node cells from CPV-immunized BALB/c mice at limiting dilutions in the presence of CPV antigen and interleukin-2 (IL-2). All isolated T cell clones exhibited the cell surface phenotype Thy1+, CD4+, CD8- and proliferated specifically in response to CPV antigen. After stimulation with CPV antigen in culture the T cell clones produced IL-2 and proliferated in the absence of exogenous IL-2. Naive mice to which CPV-specific T cell clones had been adoptively transferred developed a CPV-specific delayed type hypersensitivity reaction upon simultaneous intracutaneous injection of CPV in their ears. The ability of recombinant viral fusion proteins, representing the VP2 capsid protein of the antigenically closely related feline panleukopenia virus and of synthetic peptides derived from the amino acid sequence of the VP2 of CPV, to stimulate these T cell clones enabled the identification of T cell epitopes