ABSTRACT
Objective To perform prokaryotic expression and preliminary characterization of the recombinant poly-epitope vaccine EgG1Y162-2 (4) against cystic echinococcosis. Methods The recombinant poly-epitope vaccine EgG1Y162-2 (4) against Echinococcus granulosus based on the linker GSGGSG was subjected to structural three-dimensional (3D) modeling using immunoinformatics to analyze the structural changes and evaluate the antigenicity of the vaccine. The pET30a-EgG1Y162-2 (4) recombinant plasmid was generated using double digestion with EcoR I and Sal I, and then transformed into competent cells. Following protein induction with isopropyl-β-D-thiogalactoside (IPTG), the prokaryotic expression proteins were characterized using Western blotting, and the antigenicity of the recombinant protein was analyzed using sera from cystic echinococcosis patients and health volunteers. Results The four EgG1Y162-2 proteins coupled by the 3D structure of the recombinant vaccine EgG1Y162-2 (4) presented independent and effective expression and good antigenicity. The highest protein expression was detected in the supernatant following induction of the recombinant plasmid pET30a-EgG1Y162-2 (4) by 0.2 mmol/L IPTG at 37 °C for 4 h, and a pure protein component was seen following elution with 60 mmol/L imidazole. Western blotting analysis of the recombinant multiepitope protein HIS-EgG1Y162-2 (4) showed a band at approximately 39 kDa, and this band was recognized by sera from cystic echinococcosis patients. Conclusion A recombinant poly-epitope vaccine EgG1Y162-2 (4) against cystic echinococcosis has been successfully constructed, which provides a preliminary basis for researches on recombinant multi-epitope vaccine against cystic echinococcosis.
ABSTRACT
Objective To observe the changes of serum S100B and MBP in rats with liquid petroleum gas poisoning. Methods Fifty-four healthy adult male SD rats were randomized into normal control group (n=6), 20% LPG poisoning group (n=24) and 50% LPG poisoning group (n=24). Rat models of liquid petroleum gas poisoning were established in the later 2 groups, and controls were given the same volume of air. The rats of each group(n=6) were scored with neurological severity scale (NSS) and the blood serum was collected on the 1st, 2nd, 3nd and 7th d of poisoning, respectively. The levels of S100B and MBP were detected by euzymelinked immunosorbent assay (ELISA).Results As compared with the scores of NSS in the normal control group, those on the 1st d of poisoning in the 20% LPG poisoning group and those on the 1st and 2nd d of poisoning in the 50% LPG poisoning group were significantly higher (P＜0.05). The levels of Sl00B and MBP in 20% and 50% LPG poisoning groups were higher than those in the control group on the 1st and 2nd d of poisoning (P＜0.05); the levels of S100B and MBP in 50% LPG poisoning group were higher than those in 20% LPG poisoning group on the 1st and 2nd d of poisoning (P＜0.05). The levels of S 100B and MBP in 50% LPG poisoning group were higher than those in 20% LPG poisoning group and normal control group on the 3rd of poisoning (P＜0.05). The NSS scores and the levels of S100B and MBP in rats with LPG poisoning enjoyed the highest scores or levels on the 1st d of poisoning and those decreased after that. Conclusion The levels of S100B and MBP of rats with LPG poisoning increase, indicating that gliocytes participate in the mechanism of nervous system injury in rats with liquid petroleum gas poisoning.
ABSTRACT
Objective The potential of all central nervous system synapses to exhibit long term potentiation (LTP) or long term depression (LTD) is subject to modulation by prior synaptic activity, a higher-order form of plasticity that has been termed metaplasticity. This study is designed to examine the plasticity and metaplasticity in the lateral perforant path of rat. Methods Field potential was measured with different priming and conditioning stimulation protocols. Results Ten-hertz priming, which does not affect basal synaptic transmission, caused a dramatic reduction in subsequent LTP at lateral perforant path synapses in vitro, and the reduced LTP lasted for at least 2 h. The LTD was unaffected. The reduction of LTP in the lateral perforant path was also readily induced by applying priming antidromically at the mossy fibers. Conclusion Priming with 10 Hz, which is within a frequency range observed during physiological activity, can cause potent, long-lasting inhibition of LTP, but not LTD. This form of metaplasticity adds a layer of complexity to the activity-dependent modification of synapses within the dentate gyrus.