5'-Nucleotidase is dispensable for the growth of Salmonella Typhimurium but inhibits the bactericidal activity of macrophage extracellular traps.

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a zoonotic pathogen that causes severe gastroenteritis. The 5'-nucleotidases of pathogens can dephosphorylate adenosine phosphates, boost adenosine levels and suppress the pro-inflammatory immune response.

Identification and Characterization of the Nuclease Activity of the Extracellular Proteins from Salmonella enterica Serovar Typhimurium.

Pathogens have evolved an array of strategies to establish a productive infection. The extracellular proteins secreted by pathogens are one of unique mechanisms to evade the host innate immune response. Many secretory proteins transported by the bacterial secretion systems have been widely investigated in Salmonella.

Effect of gga-miR-155 on cell proliferation, apoptosis and invasion of Marek's disease virus (MDV) transformed cell line MSB1 by targeting RORA.

Background: Marek's disease (MD) is caused by the oncogenic Marek's disease virus (MDV), and is a highly contagious avian infection with a complex underlying pathology that involves lymphoproliferative neoplasm formation. MicroRNAs (miRNAs) act as oncogenes or tumor suppressors in most cancers. The gga-miR-155 is downregulated in the MDV-infected chicken tissues or lymphocyte lines, although its exact role in tumorigenesis remains unclear.

Identification and characterization of a Streptococcus suis immunogenic ornithine carbamoytransferase involved in bacterial adherence.

Background: Streptococcus suis (SS) is a major swine pathogen and a serious zoonotic pathogen causing septicemia and meningitis in piglets and humans. Using an immunoproteomic approach, we previously brought evidence that ornithine carbamoytransferase (OCT) may represent a vaccine candidate to protect against S. suis biofilm-related and acute infections.

[Nuclease activity of the recombinant plancitoxin-1-like proteins with mutations in the active site from Trichinella spiralis].

Although there are 125 predicted DNase Ⅱ-like family genes in the Trichinella spiralis genome, plancitoxin-1-like (Ts-Pt) contains the HKD motif, a typical conserved region of DNase Ⅱ, in N- and C-terminal. It is generally believed that histidine is the active site in DNase Ⅱ. To study the nuclease activity of recombinant Ts-Pt with mutations in the active site from T.

[Expression and adjuvant effects of the fusion peptide TBP5].

Thymopentin (TP5) and bursopentin (BP5) are both immunopotentiators. To explore whether the TP5-BP5 fusion peptide (TBP5) has adjuvant activity or not, we cloned the TBP5 gene and confirmed that the TBP5 gene in a recombinant prokaryotic expression plasmid was successfully expressed in Escherichia coli BL21. TBP5 significantly promoted the proliferation of thymic and splenic lymphocytes of mice.

[Antitumor mechanism of Bursopentin (BP5)].

Objective: Bursopentin (BP5) is a multi-functional bioactive peptide with functions of immunomodulatory, antioxidant and antitumor. However, the antitumor mechanism of BP5 is still unclear.

Methods: We constructed T7 phage cDNA library of DT40 cells, and the proteins interacted with BP5 were identified.

A eukaryotic expression plasmid carrying chicken interleukin-18 enhances the response to newcastle disease virus vaccine.

Interleukin-18 (IL-18) is an important cytokine involved in innate and acquired immunity. In this study, we cloned the full-length chicken IL-18 (ChIL-18) gene from specific-pathogen-free (SPF) chicken embryo spleen cells and provided evidence that the ChIL-18 gene in a recombinant plasmid was successfully expressed in chicken DT40 cells. ChIL-18 significantly enhanced gamma interferon (IFN-γ) mRNA expression in chicken splenocytes, which increased IFN-γ-induced nitric oxide (NO) synthesis by macrophages.

Bursin-like peptide (BLP) enhances H9N2 influenza vaccine induced humoral and cell mediated immune responses.

Vaccination with H9N2 avian influenza whole-inactivated virus (WIV) has been shown to be ineffective at eliciting sufficient humoral and cellular immunity against H9N2 avian influenza virus. This study assessed the effects of a synthetic Bursin-like epitope peptide (BLP) as adjuvant for H9N2 WIV in mice. Titers HI and avian influenza virus neutralizing antibodies, subtypes of HA antibodies, T helper (Th) cytokine levels, cytotoxic T-lymphocyte activities and changes in spleen T-cell subsets and natural killer cells were determined.

Synonymous codon usage of the VP2 gene of a very virulent infectious bursal disease virus isolate serial passaged in chicken embryos.

Three very virulent infectious bursal disease virus (vvIBDV) strains were isolated from a single farm and shown to be phylogenetically related to the vvIBDV isolate UK661. In this study, a comparative analysis of the synonymous codon usage in the hypervariable region of theVP2 (vVP2) gene of the vvIBDV strains was done on viruses serially passaged in chicken embryos. Sequencing demonstrated that codons change during the serial passage in the vVP2 gene of the viruses.

[Immunogenicity and protective efficacy of pertactin recombinants against Bordetella bronchiseptica challenge].

Objective: In this study we showed the immunogenicity and protective efficacy of five pertactin recombinants against Bordetella bronchiseptica (Bb) challenge.

Methods And Results: The complete coding sequence (2040 bp) of the prn gene (PRN) and its fragments,5'-terminal 1173 bp fragment (PN),3'-terminal 867 bp fragment (PC), two copies of region I (654 bp; PR I) in PN, and 2 copies of region II (678 bp; PR II) in PC, were separately cloned into the prokaryotic expression vector pGEX-KG, and expressed in the Eschierichia coli BL21 (DE3) using induction by isopropyl-beta-D-thiogalactopyranoside. The recombinant proteins were named GST-PRN, GST-PN, GST-PC, GST-2PR I and GST-2PR II.

[Expression and analysis of recombinant chicken IL-18 in Pichia pastoris.].

Aim: Expression and analysis of recombinant chicken IL-18 in Pichia pastoris.

Methods: Chicken IL-18 mature peptide gene was amplified from the recombinant plasmid pMD18-T-ChIL-18 by PCR, and was subcloned into Pichia pastoris expression vector pPICZalphaA to construct the recombinant plasmid pPICZalphaA-ChIL-18. After identified by restriction enzymes digestion analysis, PCR and DNA sequencing, the recombinant plasmid was transformed into Pichia pastoris X-33.

Molecular characteristic of VP2 gene of infectious bursal disease viruses isolated from a farm in two decades.

Infectious bursal disease virus (IBDV) is a double-stranded RNA virus in the Birnaviridae family. Four pathotypes, attenuated, virulent, antigenic variant, and very virulent, have been identified. In this study, we examined the phylogenetic relationship of 25 field isolates that were collected from a single farm during 1989-2008.