Objective:To highly express HIV-1p17 in E.coli and purify the protein.Methods:①Recombinant plasmid was constructed by inserting HIV-1p17 gene amplified by PCR into plasmid vector,pET28c;②The recombinant plasmid was expressed in BL21,BL21(DE3),BL21(DE3) plysS and HMS174(DE3) of E.coli separately;③The target protein were purified with Ni-NTA resin;④The purified protein was detected by western blot and ELISA.Results:The expression of the P17 protein in BL21(DE3) represented up to 32% of total protein in E.coli,which was the most amounts compared with other kinds of E.coli.The purity of the purified protein reached 95%.The purified protein was recognized by HIV-1P17McAb as well as by HIV-1 positive serum.Conclusion:The recombinant plasmid is highly expressed in BL21(DE3) of E.coli that can be proceeded to the immunocompetence and the bioactivity research.The method of Ni-NTA resin is simple with low protein losing and high purity.And the purified p17 can be employed in early detection of HIV-1 infection and prediction of the clinical progression.

ObjectiveTo reveal the molecular mechanism of Angong Niuhuangwan（AGNH） in improving traumatic brain injury（TBI） based on single cell sequencing. MethodSeventy-five male SD rats were randomly divided into the sham group， model group， piracetam group（3.6 g·kg^-1）， AGNH low- and high-dose groups（0.09， 0.27 g·kg^-1）， with 15 rats in each group. In addition to the sham group， the other 4 groups used the modified Feeney free-fall impact method to prepare TBI model， and the drugs were administered by gavage immediately after modeling， 24 hours later， the modified neurological deficit score（mNSS） was performed， and brain tissue was isolated to determine the degree of cerebral edema. Hematoxylin-eosin（HE） staining was used to observe the injury degree in the cortex， CA1 region and CA3 region of brain tissue. The expression levels of cyclooxygenase-2（COX-2）， interferon regulatory factor 1（IRF1）， Janus kinase 2（JAK2） and suppressor of cytokine signaling 3（SOCS3） were observed by immunofluorescence（IF） staining. The levels of interleukin（IL）-6， IL-18， IL-1β， IL-17A， tumor necrosis factor-α（TNF-α）， Caspase-1 and nucleotide binding oligomerization domain（NOD）-like receptor heat protein domain associated protein 3（NLRP3） inflammasome were determined by enzyme-linked immunosorbent assay（ELISA）. The regulation of AGNH on each cell population was analyzed by single cell sequencing， and differentially expressed genes were analyzed by Gene Ontology（GO） and Kyoto Encyclopedia of Genes and Genomes（KEGG）， which led to construct microglia differentially expressed gene network to search for the key targets， and validated by ELISA and IF. ResultCompared with the sham group， the mNSS and brain water content were significantly increased in the model group（P<0.01）. Compared with the model group， mNSS and brain water content in the low and high dose AGNH groups were decreased（P<0.05，P<0.01）. HE staining results showed that compared with the sham group， the cells in the cerebral cortex and hippocampus of rats in the model group were seriously lost， and the cells were arranged loosely（P<0.01）. Compared with the model group， AGNH could significantly increase the density of neurons in the CA1 and CA3 regions of the cerebral cortex and hippocampus， making the arrangement more compact， as well as improved cell morphology（P<0.05，P<0.01）. ELISA and IF staining showed that AGNH could reduce the levels of Caspase-1， IL-17A， TNF-α， NLRP3 and COX-2 in brain tissue of TBI rats（P<0.05， P<0.01）. A total of 13 cell subsets were identified by single cell sequencing， among which microglia played an important role in neuroimmunity. The results of GO enrichment analysis of differentially expressed genes in microglia showed that AGNH improved TBI in response to inflammation and TNF-α. KEGG enriched IL-17 signaling pathway， TNF signaling pathway， Toll-like receptor signaling pathway， etc. The results of network analysis showed that the key targets of AGNH in regulating TBI might be IL-6， IL-1β， JAK2， SOCS3， IRF1. IF and ELISA verification results showed that compared with the sham group， SOCS3 expression in microglia was decreased in the model group， and the expressions of IL-6， IL-1β， JAK2 and IRF1 were increased（P<0.01）. Compared with the model group， AGNH could increase the expression of SOCS3， decrease the expression of IL-6， IL-1β， JAK2， IRF1 （P<0.05， P<0.01）. ConclusionAGNH can reduce the degree of brain edema and brain injury， decrease the expression of inflammatory factors， and inhibit the expression of NLRP3 and its downstream Caspase-1 in TBI rats， which may act on the targets of IL-6， IL-1β， JAK2， IRF1 and SOCS3 in microglia.