Evaluation of Chitosan Derivatives Modified Mesoporous Silica Nanoparticles as Delivery Carrier.

Chitosan is a non-toxic biological material, but chitosan is insoluble in water, which hinders the development and utilization of chitosan. Chitosan derivatives -2-Hydroxypropyl trimethyl ammonium chloride (-2-HACC) and carboxymethyl chitosan (CMCS) with good water solubility were synthesized by our laboratory. In this study, we synthesized mesoporous SiO nanoparticles by the emulsion, and then the mesoporous SiO nanoparticles were modified with γ-aminopropyltriethoxysilane to synthesize aminated mesoporous SiO nanoparticles; CMCS and -2-HACC was used to cross-link the aminated mesoporous SiO nanoparticles to construct SiO@CMCS--2-HACC nanoparticles.

Adjuvants and delivery systems based on polymeric nanoparticles for mucosal vaccines.

Most pathogens enter the body through mucosal surfaces. Therefore, vaccination through the mucosal route can greatly enhance the mucosal immune response. Vaccination via the mucosal surface is the most effective way to trigger a protective mucosal immune response, but the vast majority of vaccines used are administered by injection.

Sex determination by SRY PCR and sequencing of Tasmanian devil facial tumour cell lines reveals non-allograft transmission.

Devil facial tumour disease (DFTD) is an infectious tumour disease and was hypothesised to be transmitted by allograft during biting based on two cytogenetic findings of DFTD tumours in 2006. It was then believed that DFTD tumours were originally from a female devil. In this study the devil sex-determining region Y (SRY) gene was PCR amplified and sequenced, and six pairs of devil SRY PCR primers were used for detection of devil SRY gene fragments in purified DFTD tumour cell lines.

Effects of reticuloendotheliosis virus infection on cytokine production in SPF chickens.

Infection with reticuloendotheliosis virus (REV), a gammaretrovirus in the Retroviridae family, can result in immunosuppression and subsequent increased susceptibility to secondary infections. The effects of REV infection on expression of mRNA for cytokine genes in chickens have not been completely elucidated. In this study, using multiplex branched DNA (bDNA) technology, we identified molecular mediators that participated in the regulation of the immune response during REV infection in chickens.

Complete genome sequence of the first Chinese virulent infectious laryngotracheitis virus.

Infectious laryngotracheitis (ILT) is an acute respiratory disease caused by infectious laryngotracheitis virus (ILTV). The complete genome sequences of five attenuated ILTV vaccine strains and six virulent ILTV strains as well as two Australian ILTV field strains have been published in Australia and the USA so far. To provide the complete genome sequence information of ILTVs from different geographic regions, the whole genome of ILTV LJS09 isolated in China was sequenced.

Detection of infectious laryngotracheitis virus by real-time PCR in naturally and experimentally infected chickens.

Infectious laryngotracheitis (ILT) is an acute, highly contagious upper-respiratory infectious disease of chickens. In this study, a real-time PCR method was developed for fast and accurate detection and quantitation of ILTV DNA of chickens experimentally infected with ILTV strain LJS09 and naturally infected chickens. The detection lower limit of the assay was 10 copies of DNA.

Avirulent Marek's disease virus type 1 strain 814 vectored vaccine expressing avian influenza (AI) virus H5 haemagglutinin induced better protection than turkey herpesvirus vectored AI vaccine.

Background: Herpesvirus of turkey (HVT) as a vector to express the haemagglutinin (HA) of avian influenza virus (AIV) H5 was developed and its protection against lethal Marek's disease virus (MDV) and highly pathogenic AIV (HPAIV) challenges was evaluated previously. It is well-known that avirulemt MDV type 1 vaccines are more effective than HVT in prevention of lethal MDV infection. To further increase protective efficacy against HPAIV and lethal MDV, a recombinant MDV type 1 strain 814 was developed to express HA gene of HPAIV H5N1.

Preparation and efficacy of a live newcastle disease virus vaccine encapsulated in chitosan nanoparticles.

Background: Newcastle disease (ND) is a highly contagious viral disease of poultry caused by pathogenic strains of the Newcastle disease virus (NDV). Live NDV vaccines are administered by drinking water, eyedrops or coarse aerosol spray. To further enhance mucosal immune responses, chitosan nanoparticles were developed for the mucosal delivery of a live NDV vaccine.

Identification of a conserved B-cell epitope on reticuloendotheliosis virus envelope protein by screening a phage-displayed random peptide library.

Background: The gp90 protein of avian reticuloendotheliosis-associated virus (REV-A) is an important envelope glycoprotein, which is responsible for inducing protective antibody immune responses in animals. B-cell epitopes on the gp90 protein of REV have not been well studied and reported.

Methods And Results: This study describes the identification of a linear B-cell epitope on the gp90 protein by screening a phage-displayed 12-mer random peptide library with the neutralizing monoclonal antibody (mAb) A9E8 directed against the gp90.

Expression of HA of HPAI H5N1 virus at US2 gene insertion site of turkey herpesvirus induced better protection than that at US10 gene insertion site.

Herpesvirus of turkey (HVT) is being widely used as a vector for development of recombinant vaccines and US2 and US10 genes are often chosen as insertion sites for targeted gene expression. However, the different effects of the two genes for generation of recombinant HVT vaccines were unknown. In order to compare the effects of inserted genes in the two sites on the efficacy of the recombinant vaccines, host-protective haemagglutinin (HA) gene of the highly pathogenic avian influenza virus (HPAIV) H5N1 was inserted into either US2 or US10 gene locus of the HVT.

Humoral immune responses in brushtail possums (Trichosurus vulpecula) induced by bacterial ghosts expressing possum zona pellucida 3 protein.

The introduced common brushtail possum (Trichosurus vulpecula) is a major pest in New Zealand and immunocontraceptive vaccines are being developed for biocontrol of possum populations, with bacterial ghosts (BGs) being evaluated as a means of oral delivery. Recombinant BGs expressing possum zona pellucida 3 protein (ZP3) as an L' membrane-anchored protein (ZP3-L') or as an S-layer SbsA-fusion protein (MBP-SbsA-ZP3) were produced by the expression of the cloned bacteriophage phiX174 lysis gene E in E. coli NM522.

Identification and evaluation of an infertility-associated ZP3 epitope from the marsupial brushtail possum (Trichosurus vulpecula).

Immunologically based fertility control vaccines against zona pellucida (ZP) proteins are being developed in New Zealand for biocontrol of the brushtail possum (Trichosurus vulpecula), an introduced Australian marsupial pest. We have shown that immunization of female possums with recombinant possum ZP3 protein (rZP3) reduced fertility by 79%. To enhance the specificity of possum immunocontraceptive vaccines, B-cell epitopes on possum ZP3 protein were mapped using sera of female possums immunized with possum rZP3 and subjected to a fertility trial.

Bacterial ghosts as a delivery system for zona pellucida-2 fertility control vaccines for brushtail possums (Trichosurus vulpecula).

The introduced brushtail possum is a serious pest in New Zealand and there is much interest in the development of an immunocontraceptive vaccine for population control. Immunisation of female possums against recombinant possum zona pellucida protein-2 (ZP2) is known to reduce embryo production by 72-75% but successful development of fertility control will depend on a delivery system that is effective for field use. Bacterial ghost vaccine technology is a promising system to formulate a non-living vaccine for bait or aerosol delivery.

Immunogenicity and contraceptive potential of three infertility-relevant zona pellucida 2 epitopes in the marsupial brushtail possum (Trichosurus vulpecula).

In a previous study, three infertility-relevant epitopes of possum ZP2 (Pep12 (amino acids 111-125), Pep31 (amino acids 301-315), and Pep44 (amino acids 431-445)) were identified using sera from possums (Trichosurus vulpecula) immunized with recombinant possum zona pellucida 2 (ZP2) constructs, and a synthetic peptide library of possum ZP2 protein. In this study, the three peptides were conjugated to keyhole limpet hemocyanin and 300 mug of each conjugated peptide were administered subcutaneously to female possums (n = 20 per peptide) in complete Freund's adjuvant. Immunogen doses were repeated 3 and 6 weeks later using incomplete Freund's adjuvant.

Mapping of B cell epitopes on the zona pellucida 2 protein of a marsupial, the brushtail possum (Trichosurus vulpecula).

Immunocontraceptive vaccines against zona pellucida (ZP) proteins are being developed for brushtail possum (Trichosurus vulpecula) management in New Zealand. Mapping of B cell epitopes on the ZP2 protein of possums was undertaken in this study to define the antigenic regions that may be crucial to sperm-egg binding. The amino acid sequence of the full-length possum ZP2 protein (712 amino acids) was used to synthesize a complete set of 71 (15-mer) biotinylated peptides with an offset of five amino acids.

Mapping of conformational epitopes on capsid protein VP2 of infectious bursal disease virus by fd-tet phage display.

Conformational epitopes on VP2 protein of infectious bursal disease virus (IBDV) were mapped using fd-tet phage display. A gene-targeted phage display library was made using DNA fragments ranging approximately from 80 to 400 bp of the hypervariable region of the VP2 gene of IBDV strain 002-73, as neutralizing monoclonal antibodies against the VP2 protein recognize VP2 conformation-dependent epitopes within the hypervariable region. The phages were selected using immobilized monoclonal antibodies.

Identification of crucial residues of conformational epitopes on VP2 protein of infectious bursal disease virus by phage display.

A new method for identifying epitopes in viral proteins expressed by filamentous phage has been developed. Filamentous phage fUSE 1 containing the variable region of the VP2 gene of infectious bursal disease virus (IBDV) strain 002-73 was constructed. Neutralizing monoclonal antibodies 17-82 and 33-10 raised against VP2 protein were used to bind phage containing the original variable region of VP2.