Progress in bacterial urease complexes and their activation mechanisms / 生物工程学报

Urease decomposes urea to ammonia, and has application potential in agriculture and medical treatment. Urease proteins include structural proteins (UreA, UreB and UreC) and accessory proteins (UreD/UreH, UreE, UreF and UreG), each of them has its own unique role in urease maturation. The structural proteins form the active center of urease, and the accessory proteins are responsible for the delivery of nickel. We review here the structure and function of bacterial urease complexes, and how each protein interacts to complete the activation process. We hope to provide theoretical basis for the regulation of urease activity and the development of urease inhibitors.

Research progress of IL-33/ST2 signaling pathway in bone metabolism / 口腔疾病防治

@#Interleukin-33(IL-33) is a new member of the interleukin-1 (IL-1) cytokine superfamily. It can activate mast cells, lymphocytes and macrophages to produce Th2 cytokines and plays a very important role in inflammation, infection, and autoimmune disease. The classical signal pathway of IL-33 includes the isotrimer of ST2 and interleukin-1 receptor accessory protein (IL-1 RAcP), which transduces signals into cells. The IL-33/ST2 signaling pathway affects bone metabolism by activating T and B lymphocytes. This article reviews the role of the IL-33/ST2 signaling pathway in bone metabolism. The results of a literature review showed that at present, scholars at home and abroad still dispute the role of IL-33 in bone metabolism. Some scholars believe that IL-33 can inhibit osteoclast formation, and IL-33 has been recently implicated in physiological bone remodeling. However, other scholars believe that IL-33 can promote osteoclast formation and differentiation, which leads to bone absorption. IL-33 and its signaling pathway are involved in bone metabolism of alveolar bone in periodontitis and periapical periodontitis. The specific mechanism remains unclear, and further studies are warranted.

Immunogenicity of DNA vaccines encoding regulatory/accessory proteins derived from three different prevalent strains in China / 中华微生物学和免疫学杂志

0bjective To determine the immunogenicities of DNA vaccines expressing tat-rev-integrase(c-half)-vif-neffusion genes(TRIVN) derived from prevalent B', B'/C and AE recombinant subtypes of HIV-1 in China. Methods Two DNA vaccines were constructed by inserting the codon optimized tat-revintegrase(c-half)-vif-nef fusion genes derived from B' and B'/C subtype of HIV-1 into mammalian expression vector pSVI. 0. DNA vaccine containing tat-rev-integrase (c-half)-vif-nef fusion gene derived from HIV-1AE2f has been constructed previously. In vitro expression efficiencies of three DNA vaccines were determined by Western blot and their immunogenicities were compared by immunizing female BALB/c mice. IFN-γ ELISPOT assay was used to read out the specific T cell immunity. Results The constructed DNA vaccines were validated by restriction enzyme digestion and DNA sequencing. Western blot assay showed three constructed DNA vaccines could be expressed at a comparable level in vitro. After vaccination, AE-TRIVN mounted T cell immune responses at (948.0 ± 330.0) SFCs/106 splenocytes, followed by the mixed DNA vaccine[ (500.0 ± 155.0) SFCs/106 splenocytes ], RL-TRIVN r[ ( 195. 1 ± 44.0) SFCs/106 splenocytes ]and CN-TRIVN [ (89.5 ± 17.0) SFCs/106 splenocytes]. Interestingly, we observed that single DNA vaccination induced specific T cell responses predominantly targeting Integrase (C-half) and Vif, whereas the mixed DNA could significantly improve T cell responses against Nef. Conclusion AE-TRIVN was the most immunogenic among the three DNA vaccines and the mixed DNA vaccination could change the immunogenic hierarchy of T cell epitopes across the fusion genes vaccine.

Immunogenicity comparison of DNA vaccines encoding HIY-1 AE2f Tat, Rev and Nef in different gene fusion formulations / 中华微生物学和免疫学杂志

Objective To construct DNA vaccine expressing HIV-1 AE2f gp145-tat-rev-nef fusion gene( AE-Gp145TRN) and to compare the immunogenicities of DNA vaccines expressing Tat, Rev and Nef in gene fusion formulations of tat-rev-integrase(c-half)-vif-nef( AE-TRIVN) and AE-Gpl45TRN. Methods DNA vaccine was constructed by inserting the codon optimized HIV-1 AE2( gp145-tat-rev-nef fusion gene into mammalian expression DNA vector. In vitro expression efficiency of the constructed DNA vaccine was determined by Western blot and the immunogenicities of AE-Gpl45TRN and AE-TRIVN were compared by immunizing female BALB/c mice. IFN-r ELISPOT assay was used to read out the specific T cell immunity. Results Western blot assay showed the constructed DNA vaccine could be expressed efficiently in vitro. After vaccination, AE-TRIVN mounted significantly higher T cell responses against Tat, Rev and Nef[(148±91)SFCs/106 splenocytes]than Gpl45TRN[(55±28) SFCs/106 splenocytes]. Specific T cell responses elicited by AE-TRIVN predominantly targeting Rev, whereas Gpl45TRN could significantly enhance T cell responses against Nef. Conclusion AE-TRIVN and Gpl45TRN induced distinct T cell response modalities, which implied different gene fusion formulations may affect the immunogenicity of specific DNA vaccines.