High expression of the classical swine fever virus (CSFV) envelope protein E2 by a single amino acid mutation and its embedded in the pseudorabies virus (PRV) vector for immunization.

Pseudorabies (PR) and classical swine fever (CSF) are economically important infectious diseases in pigs. Most pig farms in China are vaccinated against these two diseases. Gene-deleted pseudorabies virus (PRV) can be used to develop promising and economical multivalent live attenuated viral vector vaccines. It has been reported that recombinant PRV can express a truncated E2 protein (1-338 aa), but it has not been reported that recombinant PRV can express a full-length E2 protein. We constructed nine groups of E2 proteins with different expression forms and found that the E2 protein could be expressed in vitro only when the transmembrane region of E2 was removed and the signal peptide was added. Analysis of the transmembrane region of E2 revealed that the high hydrophobicity of the E2 transmembrane region was the main reason for its inability to express. By mutating an amino acid to reduce the hydrophobicity of the transmembrane region, it was found that the full-length mutant of E2 (E2FL-muta3 or E2FL-muta4) could be expressed. The expressed full-length mutant E2 could also localize to the cell membrane. Mice immunized with a PRV vector vaccine expressing E2FL-muta3 or E2FL-muta4 developed specific cellular immunity to the E2 protein and stimulated higher levels of E2 antibody than mice immunized with a PRV vector expressing truncated E2. After immunizing the rabbits, the lethal challenge by PRV-ZJ2013 and the febrile response elicited by CSFV were simultaneously prevented. These results suggest that rPRV-dTK/gE-E2FL-muta4 is a promising bivalent vaccine against CSFV and PRV infections.

Recombinant pseudorabies virus (PRV) expressing stabilized E2 of classical swine fever virus (CSFV) protects against both PRV and CSFV.

Pseudorabies (PR) and classical swine fever (CSF) are economically important infectious diseases of pigs. Most pig farms in China are immunized against these two diseases. Here, we describe a stabilized E2 protein as an immunogen inserted into the PRV genome as a bivalent live virus-vectored vaccine. The E2 protein has 48 variant sites, there are 2-5 candidate amino acids per variant site, and the relative energy contribution of each amino acid to E2 energy was calculated. Combined substitutions of amino acids at the neighbor variant site (neighbor substitution) were performed to obtain the E2 protein sequence with the lowest energy (stabilized E2). Multiple amino acid substitutions at 48 variant sites were performed, and the results were consistent with neighbor substitutions. The stabilized E2 sequence was obtained, and its energy decreased by 22 Rosetta Energy Units (REUs) compared with the original sequence. After the recombinant PRV expressing stabilized E2 of CSFV was constructed, the secretion efficiency of stabilized E2 was increased by 2.97 times, and the thermal stability was increased by 10.5 times. Immunization of mice resulted in a 2-fold increase in antibody production, and a balanced antibody level against subtype 1.1 and subtype 2.1d E2 was achieved. In rabbits immunized, the lethal challenge of PRV-ZJ and the fever response induced by CSFV could be prevented simultaneously. These findings suggest that rPRV-muta/287aaE2 is a promising bivalent vaccine against CSFV and PRV infections.

Polydatin ameliorates hepatic ischemia-reperfusion injury by modulating macrophage polarization.

BACKGROUND: Polydatin, a glucoside of resveratrol, has been shown to have protective effects against various diseases. However, little is known about its effect on hepatic ischemia-reperfusion (I/R) injury. This study aimed to elucidate whether polydatin protects liver against I/R-induced injury and to explore the underlying mechanism. METHODS: After gavage feeding polydatin once daily for a week, mice underwent a partial hepatic I/R procedure. Serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST), hematoxylin-eosin (H&E) and TdT-mediated dUTP nick-end labeling (TUNEL) staining were used to evaluate liver injury. The severity related to the inflammatory response and reactive oxygen species (ROS) production was also investigated. Furthermore, immunofluorescence and Western blotting were used to detect macrophage polarization and the NF-κB signaling pathway in macrophages. RESULTS: Compared with the I/R group, polydatin pretreatment significantly attenuated I/R-induced liver damage and apoptosis. The oxidative stress marker (dihydroethidium fluorescence, malondialdehyde, superoxide dismutase and glutathione peroxidase) and I/R related inflammatory cytokines (interleukin-1ß, interleukin-10 and tumor necrosis factor-α) were significantly suppressed after polydatin treatment. In addition, the result of immunofluorescence indicated that polydatin reduced the polarization of macrophages toward M1 macrophages both in vivo and in vitro. Western blotting showed that polydatin inhibited the pro-inflammatory function of RAW264.7 via down-regulating the NF-κB signaling pathway. CONCLUSIONS: Polydatin protects the liver from I/R injury by remodeling macrophage polarization via NF-κB signaling.

BCAT1, a key prognostic predictor of hepatocellular carcinoma, promotes cell proliferation and induces chemoresistance to cisplatin.

BACKGROUND & AIMS: BCAT1 initiates the catabolism of branched-chain amino acids. Here, we investigated the function of BCAT1 and its transcriptional regulatory mechanism in hepatocellular carcinoma (HCC). METHODS: RNASeq was used to evaluate BCAT1 mRNA levels in HCC and normal matched specimens. After the exogenous expression of BCAT1 in BEL-7404 cells and the suppression of endogenous BCAT1 expression with shRNA in HepG2 cells, the cell proliferation, clone-forming ability and cell-cycle changes were measured with MTT assay, colony-forming assay and flow cytometry respectively. A xenograft model was used to investigate the effect of BCAT1 on cancer growth in vivo. Chromatin immunoprecipitation and luciferase reporter technologies were used to confirm the transcriptional regulation of the BCAT1 gene by MYC. The expression of the BCAT1 and MYC proteins in 122 HCC tissues was determined with an immunohistochemical analysis. RESULTS: BCAT1 mRNA was clearly increased in HCC tissues and hepatomas. The ectopic expression of BCAT1 in BEL-7404 cells enhanced their proliferation, clone formation, tumourigenic properties, S-G2 /M phase transition and chemoresistance to cisplatin. The suppression of BCAT1 expression in HepG2 cells significantly inhibited their proliferation, clone formation, and S-G2 /M phase transition and caused their chemosensitization to cisplatin. MYC affected the transcriptional regulation of BCAT1. Clinical data showed that BCAT1 expression correlated with a significantly poorer prognosis. CONCLUSION: BCAT1 plays a pathogenic role in HCC by causing cell proliferation and chemoresistance. The MYC transcription factor is involved in regulating the transcriptional activity of BCAT1. BCAT1 expression has prognostic significance for the survival of patients with HCC.

Relationship between CIP2A expression, and prognosis and MDR-related proteins in patients with advanced gastric cancer.

CIP2A is highly expressed in a variety of malignancies. We determined the expression and clinical significance of CIP2A in patients with advanced gastric cancer. CIP2A protein was expressed in 25 of 37 cancer tissue specimens. There was no correlation between CIP2A and PGP, GST-π, Topo-II, and LRP expression. Survival analysis showed significant differences between the survival rate of the CIP2A protein-positive and -negative groups (χ(2)=4.509, P=0.034), but the degree of positive expression was unrelated to survival time (χ(2)=4.639, P=0.098). CIP2A expression may have no prospective value for optimizing chemotherapy regimens, but it can be an indicator for patient prognosis.