13 research outputs found
Use of B7 costimulatory molecules as adjuvants in a prime-boost vaccination against Visna/Maedi ovine lentivirus
Modelling the Influence of Foot-and-Mouth Disease Vaccine Antigen Stability and Dose on the Bovine Immune Response
Foot and mouth disease virus causes a livestock disease of significant global socio-economic importance. Advances in its control and eradication depend critically on improvements in vaccine efficacy, which can be best achieved by better understanding the complex within-host immunodynamic response to inoculation. We present a detailed and empirically parametrised dynamical mathematical model of the hypothesised immune response in cattle, and explore its behaviour with reference to a variety of experimental observations relating to foot and mouth immunology. The model system is able to qualitatively account for the observed responses during in-vivo experiments, and we use it to gain insight into the incompletely understood effect of single and repeat inoculations of differing dosage using vaccine formulations of different structural stability
Anti-Klebsiella K30 phospholipid antibodies in systemic lupus erythematosus: Antigen cross-reactions and idiotypic sharing with antibodies to DNA andKlebsiella K30 polysaccharide
ALOPECIA UNIVERSALIS TREATED WITH ORAL CYCLOSPORINE A AND PREDNISOLONE: IMMUNOLOGIC STUDIES
Development and comparison of strain specific gag and pol real-time PCR assays for the detection of Visna/maedi virus
The aim of this study was the development of gag and pol dual labelled probe real-time PCR and RT
PCR assays to quantify the proviral load and the transcripts of the British Visna/maedi virus EV1 strain.
Primers and probes were chosen based on the consensus sequences of gag and pol clones representative
of EV1 genetic variants. Both PCRs had a detection limit of 3 copies of target gene, with a linearity over
6 orders of magnitude. The performances of the two PCRs in vivo were evaluated and compared on a
panel of DNAs extracted from blood of sheep infected experimentally with EV1. The pol assay detected in
most cases lower numbers of viral molecules than gag assay, yielding some false negative results. The gag
real-time RT PCR had a detection limit of 100 RNA molecules with a linearity over 5 orders of magnitude.
This did not result in a lower performance of the RT PCR compared to the PCR in cells permissive for
virus replication, which contain higher numbers of viral transcripts than proviral genomes. The real-time
assays developed in this study, particularly the gag assay, provide a sensitive tool which can be used to
quantify the viral load in experimental infections
Mucosal immunization against ovine lentivirus using PEI-DNA complexes and modified vaccinia Ankara encoding the gag and/or env genes
Sheep were immunized against Visna/Maedi virus (VMV) gag and/or env genes via the nasopharynxassociated
lymphoid tissue (NALT) and lung using polyethylenimine (PEI)–DNA complexes and modified
vaccinia Ankara, and challenged with live virus via the lung. env immunization enhanced humoral
responses prior to but not after VMV challenge. Systemic T cell proliferative and cytotoxic responseswere
generally low, with the responses following single gag gene immunization being significantly depressed
after challenge. A transient reduction in provirus load in the blood early after challenge was observed
following env immunization, whilst the gag gene either alone or in combination with env resulted in significantly
elevated provirus loads in lung. However, despite this, a significant reduction in lesion score
was observed in animals immunized with the single gag gene at post-mortem. Inclusion of IFN- in the
immunization mixture in general had no significant effects. The results thus showed that protective effects
against VMV-induced lesions can be induced following respiratory immunization with the single gag gene,
though this was accompanied by an increased pulmonary provirus load
Correlation of disease activity with circulating immune complexes (C1QbA) and complement breakdown products (C3D) in patients with systemic lupus erythematosus
Systemic DNA immunization against ovine lentivirus using particle-mediated epidermal delivery and modified vaccinia Ankara encoding the gag and/or env genes
To determine whether systemic immunization with plasmid DNA and virus vector against visna/maedi
virus (VMV)would induce protectiveimmuneresponses, sheepwere immunized withVMVgag and/or env
sequences using particle-mediated epidermal bombardment and injection of recombinant modified vaccinia
Ankara. The results showed that immunization induced both humoral and cell-mediated responses
prior to and after virus challenge. The vaccination protocol did not prevent infection, but immunization
with the gag gene or a combination of gag and env genes resulted in significantly reduced provirus loads
in blood and mediastinal lymph node, respectively. Provirus loads in lung and draining lymph node were
unaffected, but p25 expression was undetectable in lungs of animals immunized with a combination of
gag and env genes. Analysis of target tissues for lesions at post-mortem showed that immunization with
the env gene caused a significant increase in lesion score, while the gag gene or a combination of gag and
env genes had no effect. Inclusion of the ovine interferon- gene in the initial priming mixture had minimal
effect on immune responses, provirus load, or lesion development, although it resulted in a decreased
p25 expression in the lung. The results thus show that systemic immunization with gag or a combination
of gag and env genes reduced provirus load in blood and lymphoid tissue, respectively whereas env
immunization has no effect on provirus load but increased lesion development