Enhancement of the immunogenicity of an infectious laryngotracheitis virus DNA vaccine by a bicistronic plasmid encoding glycoprotein B and interleukin-18.

A DNA vaccine against infectious laryngotracheitis virus (ILTV) can induce specific humoral and cell-mediated immunity. However, compared to conventional vaccines, DNA vaccines usually induce poor antibody responses. To determine if co-expression of a cytokine can result in a more potent ILTV DNA vaccine, immunogenicity and protective efficacy of a monocistronic vector encoding the glycoprotein B (gB) of ILTV was compared to that of a bicistronic vector separately encoding the gB and chicken interleukin-18.

Function of PRRSV GP5 envelope protein by using pseudotyped virus.

The porcine reproductive and respiratory syndrome virus (PRRSV) is an enveloped RNA virus. Virions of PRRSV contain six membrane proteins: the major proteins GP5 and M and the minor proteins GP2, GP3, GP4, and E. The GP5 is the major envelope proteins, which was involved in the formation and infectivity of PRRSV by coaction with other membrane proteins.

[Construction of eukaryotic express vector of duck interleukin 18 gene and identification of bioactivity of its expressed protein].

Duck IL-18 gene was amplified from plasmid pGEM-DuIL-18 by PCR. The PCR product digested with Pst I and Xho I was inserted into eukaryotic express vector pcDNA3.1(+) to generate an recombinant expression plasmid pcDNA3.

[Pseudotyping of murine leukemia virus particles with porcine reproductive and respiratory syndrome virus M protein-mediated E protein].

For constructing pcDNA-ORF5, pcDNA-ORF5-ORF6, pcDNA-ORF5/6, the ORF5 and ORF6 of porcine reproductive and respiratory syndrome virus (PRRSV) were amplified by RT-PCR, and transiently transfected into 293T cells by calciumphosphate co-precipitation. After 48 h, 293T cells were collected and surveyed by flow cytometry examination. The result indicated that the expression level of the E protein that mediated by the M protein was higher than that of the E protein expressed independently.

[Characterization of murine leukemia virus recombinants bearing PRRSV GP5 glycoproteins].

The highly virulent PRRSV isolate strain HN-1/06 was cultivated on Marc-145. To study the viral entry mechanisms, the GP5 gene of PRRSV isolate was amplified by RT-PCR and cloned into pcDNA3.0 to generate the expressing plasmid pcDNA-GP5.

Cloning, in vitro expression and bioactivity of duck interleukin-18.

The encoding sequence for duck IL-18 was obtained, using reverse transcription-polymerase chain reaction, from mRNA harvested from Con A-stimulated Gushi (GS) duck splenic mononuclear cells. Recombinant duck IL-18 (rduIL-18) was produced in a prokaryotic expression system. In vitro bioactivity of rduIL-18 was determined in a lymphocyte proliferation assay and in vivo bioactivity of rduIL-18 was assessed by addition to a vaccine.

[Cloning and characterization of the promoter region of Musca domestica yolk protein-1 gene].

A partial Musca domestica genomic library was constructed. It was consisted of 1.2 x 10(5) recombinants with insert length ranging from 10 kb to 23 kb(15 kb average).