The I226R protein of African swine fever virus inhibits the cGAS-STING-mediated innate immune response / 生物工程学报

This study aimed to explore the mechanism of how African swine fever virus (ASFV) I226R protein inhibits the cGAS-STING signaling pathway. We observed that I226R protein (pI226R) significantly inhibited the cGAS-STING-mediated type Ⅰ interferons and the interferon-stimulated genes production by dual-luciferase reporter assay system and real-time quantitative PCR. The results of co-immunoprecipitation assay and confocal microscopy showed that pI226R interacted with cGAS. Furthermore, pI226R promoted cGAS degradation through autophagy-lysosome pathway. Moreover, we found that pI226R decreased the binding of cGAS to E3 ligase tripartite motif protein 56 (TRIM56), resulting in the weakened monoubiquitination of cGAS, thus inhibiting the activation of cGAS and cGAS-STING signaling. In conclusion, ASFV pI226R suppresses the antiviral innate immune response by antagonizing cGAS, which contributes to an in-depth understanding of the immune escape mechanism of ASFV and provides a theoretical basis for the development of vaccines.

Eukaryotic expression of GP5 and M protein of porcine reproductive and respiratory syndrome virus and immunogenicity evaluation / 生物工程学报

In order to understand the prevalence and evolution of porcine reproductive and respiratory syndrome virus (PRRSV) in China and to develop subunit vaccine against the epidemic lineage, the genetic evolution analysis of PRRSV strains isolated in China from 2001 to 2021 was performed. The representative strains of the dominant epidemic lineage were selected to optimize the membrane protein GP5 and M nucleotide sequences, which were used, with the interferon and the Fc region of immunoglobulin, to construct the eukaryotic expression plasmids pCDNA3.4-IFNα-GP5-Fc and pCDNA3.4-IFNα-M-Fc. Subsequently, the recombinant proteins IFNα-GP5-Fc and IFNα-M-Fc were expressed by HEK293T eukaryotic expression system. The two recombinant proteins were mixed with ISA206VG adjuvant to immunize weaned piglets. The humoral immunity level was evaluated by ELISA and neutralization test, and the cellular immunity level was detected by ELISPOT test. The results showed that the NADC30-like lineage was the main epidemic lineage in China in recent years, and the combination of IFNα-GP5-Fc and IFNα-M-Fc could induce high levels of antibody and cellular immunity in piglets. This study may facilitate the preparation of a safer and more effective new PRRSV subunit vaccine.

Effect of Different Penetration Enhancers on Percutaneous Absorption of Xiaoyan Runma Mucilage / 医药导报

Objective To investigate the effects of different penetration enhancers on percutaneous absorption of Xiaoyan Runma mucilage in vitro, and to improve the curative efficacy of this mucilages through selection of the effective penetration enhancers. Methods Xiaoyan Runma mucilage was prepared with different penetration enhancers. An intelligent permeability instrument was used for in vitro percutaneous absorption test of rats , with isolated mice abdomen skin serving as in vitro transdermal barrier and saline isotonic solution as receptor fluid. Then the contents of lidocaine hydrochloride in receptors were determined by HPLC.The accumulative transit dose (Q) and percutaneous permeability (J) within 12 h were calculated and compared with those of mucilage without any enhancer. Results With Q value serving as an index, different enhancers had different promote permeation effects on Xiaoyan Runma mucilage, and the effects in descending order were as follows:4% azone [(222.75±3.4) μg?(cm2)-1]>2% azone[(207.42±5.1) μg?(cm2)-1]>3% menthol [(183.38±4.9) μg?(cm2)-1]>5%menthol [(160.82±5.4) μg?(cm2)-1]>2% azone+3% menthol [(151.25±5.5) μg?(cm2)-1]>2% azone+5% isopropyl myristate [(127.26±7.1) μg?(cm2)-1]>2% oleic acid [(125.16±6.5) μg?(cm2)-1]>no enhancer [(109.82±8.2)μg?(cm2)-1].4% azone was the best penetration enhancer for the mucilage delivery in vitro, with Q and J value as [(222.75± 3.4)μg?( cm2 )-1 ] and 19. 896 μg?( cm2 )-1?h-1 , respectively, which was 2. 08 times those of mucilages without any enhancer. Conclusion Being as a transdermal absorption enhancer of Xiaoyan Runma mucilage, 4% azone has the best effect. This study can provide the optimal formulation for transdermal delivery system of Xiaoyan Runma mucilage.

Preparation of cationic dextran microspheres loaded with tetanus toxoid and study on the mechanism of protein loading / 药学学报

The aim of this study is to prepare cationic biodegradable dextran microspheres loaded with tetanus toxoid (TT) and to investigate the mechanism of protein loading. Positively charged microspheres were prepared by polymerization of hydroxylethyl methacrylate derivatized dextran (dex-HEMA) and dimethyl aminoethyl methacrylate (DMAEMA) in an aqueous two-phase system. The loading of the microspheres with TT was based on electrostatic attraction. The net positive surface charge increased with increasing amounts of DMAEMA. Confocal images showed fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) could penetrate into cationic dextran microspheres but not natural dextran microspheres. TT loading efficiency by post-loading was higher compared with by pre-loading. Even though TT is incorporated in the hydrogel network based on electrostatic interaction, still a controlled release can be achieved by varying the initial network density of the microspheres.