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Objective:To investigate the effect of tripartite motif-containing 23 (Trim23) on the differentiation and maturation of dendritic cells and the possible mechanism.Methods:Mouse bone marrow-derived dendritic cells (BMDCs) were prepared from bone marrow cells of C57BL/6 mice with the presence of Flt3L. Real-time quantitative PCR and Western blot were used to detect the expression of Trim23 in BMDCs after LPS stimulation. An overexpression vector for full-length Trim23 (Trim23 OE) was constructed and transfected into BMDCs, and the pcDNA3.1 empty vector was used as control. Flow cytometry was used to detect the expression of CD80, CD86, CD40 and MHCⅡ on the surface of vector-transfected BMDCs after LPS stimulation and ELISA was used to detect the secretion of IL-12p40, TNF-α, IL-6 and IL-10 by these cells. CD8 + and CD4 + T cells were isolated from spleen and lymph nodes of OT-Ⅰ and OT-Ⅱ mice by magnetic beads and co-cultured with LPS-treated BMDCs in the presence of ovalbumin (OVA). Flow cytometry was used to detect the proliferation and differentiation of CD8 + and CD4 + T cells. Western blot was performed to analyze the phosphorylation of p38, ERK1/2 and AKT in BMDCs. Two overexpression vectors for Trim23 mutants lacking RING or ARF domain (Trim23 ΔRING and Trim23 ΔARF) were constructed and transfected into BMDCs. Then flow cytometry and ELISA were used to detect the expression of surface molecules and cytokines. Results:The expression of Trim23 in BMDCs was significantly down-regulated after LPS stimulation. The expression of MHCⅡ, CD86 and CD80 and the secretion of TNF-α and IL-6 decreased significantly in BMDCs overexpressing Trim23. Furthermore, overexpression of Trim23 inhibited the ability of BMDCs to induce the proliferation and differentiation of CD4 + T cells and the proliferation of CD8 + T cells. Western blot showed that the phosphorylation of p38 and ERK1/2 decreased significantly in Trim23-overexpressing BMDCs. Compared with wildtype Trim23, overexpression of Trim23 ΔRING had no significant influence on the expression of surface molecules (MHCⅡ and CD86) and the secretion of cytokines (TNF-α and IL-6) in BMDCs stimulated by LPS. Conclusions:Trim23 overexpression inhibited the maturation and immune activation of BMDCs via MAPK signal pathway and its RING domain. This study provided reference for targeting Trim23 to improve the immune response of dendritic cell-based tumor vaccines.
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Nonribosomal peptide synthetases (NRPS) catalyze the synthesis of nonribosomal peptide (NRP) compounds with structural and functional diversities, including more than 20 marketed drugs. This review focuses on the recent advances in the functional domains of NRPS and their mechanisms of action, as well as the unconventional assembly patterns such as iterative NRPS, module skipping, in trans aminoacylation and tandem adenylation domains. This review provides the theoretical basis for exploring new nonribosomal peptide compounds and the development of new drugs.
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Objective@#To construct the mutants of ARID1A gene, which is an important component in human chromosomal remodeling complex Switch/Sucrose Non Fermentable (SWI/SNF), and identify their overexpression in liver cancer HepG2 cells.@*Methods@#Overlap PCR was used to construct domain truncated mutantss pcDNA6-ARID1A/ΔARID and pcDNA6-ARID1A/ΔD UF3518 based on wild type plasmids pcDNA6-ARID1A. Lipofectionmethod was used to transfect the wild type and mutants into HepG2. Real-time PCR and western blotting were used to confirm the overexpression of ARID1A and the mutants.@*Results@#SDS-PAGE and sequencingresult confirmed the successful construction of pcDNA6-ARID1A/ΔARID and pcDNA6-ARID1A/ΔDUF3518. Real-time PCR and western blottingresult confirmed the overexpression of both mRNA and protein of wild type ARID1A and ARID1A/ΔARID. The mRNA levels indicated that ARID1A/Δ DUF3518 were overexpressed, but the protein levels were quite low.@*Conclusions@#Functional domain truncated mutants of ARID1A were successfully constructed. Overexpression of wild type ARID1A and ARID1A/ΔARID in liver cancer HepG2 cells was successful. Loss of ARID1A/ΔDUF3518 protein suggest that DUF3518 may contribute to the protein structure stability.
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Nuclear proteins often form punctiform structures, but the precise mechanism for this process is unknown. As a preliminary study, we investigated the aggregation of an HSV-1 immediate-early protein,infected-cell protein 22 (ICP22), in the nucleus by observing the localization of ICP22-EGFP fusion protein.Results showed that, in high-level expression conditions, ICP22-EGFP gradually concentrates in the nucleus,persists throughout the cell cycle without disaggregation even in the cell division phase, and is finally distributed to daughter cells. We subsequently constructed a mammalian cell expression system, which had tetracyclinedependent transcriptional regulators. Consequently, the location of ICP22-EGFP in the nucleus changed with distinct induction conditions. This suggests that the cellular location of ICP22 is also influenced by promoter regulation, in addition to its own structure. Our findings provide new clues for the investigation of transcriptional regulation of viral genes. In addition, the non-protease reporter system we constructed could be utilized to evaluate the role of internal ribosome entry sites (IRES) on transcriptional regulation.