Objective:To construct three photosensitive fusion proteins between protein G C3 domain and Avitag for site-spe-cific biotinylation of goat IgG.Methods:DNA sequences of protein G C3 domain with amber codon mutation and C-terminal containing 1,2,3 Avitag were obtained by chemical synthesis,respectively,and sub-cloned into pTXB1 plasmid to construct three fusion pro-tein expression vectors.Three plasmids and pEVOL-pBpF plasmid were co-transformed into competent bacterium E.coli BL21,respec-tively.Target fusion proteins CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 were prepared using genetic codon extension technology,and were purified by His Trap Chelating HP column,then biotinylated by Avitag/BirA system.Photo-conjugation efficiency,crosslink site and antigen-binding activity of photo-conjugates were investigated by SDS-PAGE,control experiment,and competitive ELISA.Results:Three expression vectors were successfully constructed,and three designed photoactivatable fusion proteins CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 were successfully expressed with molecular weights consistent with their theoretical values.Heavy-chain conjugation efficiencies of biotinylated fusion protein with goat IgG were 85%with Fc-specific conjugation,and conjugates maintained its antigen-binding activity after photo-conjugation.Conclusion:CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 fusion proteins are successfully prepared,and mediates by those photosensitive fusion proteins,biotins molecules are conjugated to Fc fragment of goat IgG,results site-specific biotinylation of goat IgG.

Objective:To construct three photosensitive fusion proteins between protein G C3 domain and Avitag for site-spe-cific biotinylation of goat IgG.Methods:DNA sequences of protein G C3 domain with amber codon mutation and C-terminal containing 1,2,3 Avitag were obtained by chemical synthesis,respectively,and sub-cloned into pTXB1 plasmid to construct three fusion pro-tein expression vectors.Three plasmids and pEVOL-pBpF plasmid were co-transformed into competent bacterium E.coli BL21,respec-tively.Target fusion proteins CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 were prepared using genetic codon extension technology,and were purified by His Trap Chelating HP column,then biotinylated by Avitag/BirA system.Photo-conjugation efficiency,crosslink site and antigen-binding activity of photo-conjugates were investigated by SDS-PAGE,control experiment,and competitive ELISA.Results:Three expression vectors were successfully constructed,and three designed photoactivatable fusion proteins CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 were successfully expressed with molecular weights consistent with their theoretical values.Heavy-chain conjugation efficiencies of biotinylated fusion protein with goat IgG were 85%with Fc-specific conjugation,and conjugates maintained its antigen-binding activity after photo-conjugation.Conclusion:CBpa-Avitag,CBpa-(Avitag)2 and CBpa-(Avitag)3 fusion proteins are successfully prepared,and mediates by those photosensitive fusion proteins,biotins molecules are conjugated to Fc fragment of goat IgG,results site-specific biotinylation of goat IgG.

Objective To investigate the effect of cinobufacini on inhibiting colorectal cancer metastasis by regula-ting the polarization of M2 macrophages.Methods THP-1 was induced into M0 type macrophages.The condi-tioned medium of HCT116 cells was collected to stimulate M0 type macrophages.The polarization of M2 type mac-rophages was observed by flow cytometry,real-time quantitative PCR and ELISA experiments.The conditioned me-dium of M0 type macrophages and HCT116-Mφ cells was collected to stimulate HCT116 cells.The ability of migra-tion and invasion was observed by wound healing assay and Transwell assay.The effect of cinobufacini on the via-bility of HCT116 cells was detected by CCK-8 assay.The conditioned medium of HCT116 and HCT116+cinobufa-cini was collected to stimulate M0 type macrophages.The polarization of M2 type macrophages was observed by flow cytometry,real-time quantitative PCR and ELISA experiments.The conditioned media of HCT116-Mφ cells and(HCT116+cinobufacini)-Mφ cells were collected to stimulate HCT116 cells.The changes of migration and inva-sion ability were observed by wound healing assay and Transwell assay.Results After stimulation of M0 type mac-rophages in HCT116 cell conditioned medium,the morphology of M0 macrophages turned into fusiform cells,the proportion of CD11b+CD206+cells increased,and the expression of M2 macrophage markers IL-10 and TGF-β in-creased.The migration and invasion ability of HCT116 cells were significantly enhanced after stimulation in the conditioned medium of HCT1 16-Mφ cells.After the addition of cinobufacini,not only the polarization proportion of M2 macrophages decreased,but also the metastatic effect mediated by M2 macrophages was inhibited.Conclusion HCT116 cells can induce the polarization of M2 macrophages,while cinobufacini can inhibit the tumor metastasis mediated by M2 macrophages by inhibiting the polarization of M2 macrophages.

Objective To investigate the role of bufalin(BU)in inhibiting M2-type macrophage-mediated colorec-tal cancer metastasis.Methods Human acute leukemia mononuclear cells(THP-1)were differentiated into M0 macrophages using phorbol ester induction(PMA)for 48 hours.The M0 macrophages were then treated with IL-4 and IL-13 medium.Surface markers and morphological changes were observed through ELISA,morphology,and RT-qPCR experiments.RT-PCR and ELISA experiments were conducted to detect the surface markers TGF-β and IL-10 of M2 macrophages.The secretion level of IL-6 in the supernatant of M2 macrophages and colorectal cancer cells HCT116 was compared using ELISA.Additionally,the effect of conditioned medium on colorectal cancer cell HCT116 was assessed through Transwell,Wound healing,RT-qPCR,and Western blot experiments.Subsequent-ly,bufalin was added to the conditioned medium and the changes in AKT/PI3K protein,migration,and epithelial-mesenchymal transition ability in HCT116 were observed using Western blot,Transwell,Wound healing and RT-qPCR experiments.Results THP-1 were successfully differentiated into M2 macrophages.The activation of AKT/PI3K protein in HCT116 cells was induced by the secretion of IL-6 from M2 macrophages,which in turn promoted the migration and epithelial-mesenchymal transition ability of the HCT116 cells.The migration and epithelial-mes-enchymal transition mediated by M2 macrophages in HCT116 cells were effectively inhibited by Bufalin.Conclu-sion The release of IL-6 from M2 macrophages activates the AKT/PI3K signaling pathway in colorectal cancer cells,thereby promoting their migration and epithelial-mesenchymal transition capacity.Moreover,bufalin exhibits inhibitory effects on this effect.

Colorectal cancer(CRC)is a common malignant tumor of the digestive system.The main treatments for CRC currently include surgical resection,chemotherapy,radiotherapy,and immunotherapy.Immunogenic cell death(ICD)is an important method ofanti-tumortherapy.ICD is a specific type of cell death that involves the release of damage-associated molecular patterns(DAMPs).These DAMPs can be effectively taken up by dendritic cells(DCs),neutrophils,and macrophages,thereby stimulating adaptive immune responses in the body.However,colorectal cancer is considered a"cold tumor"with relatively low immunogenicity,resulting in a low response rate to immunotherapy.Inducing ICD can potentially enhance the immunogenicity of colorectal cancer,leading to long-term tumor control.This review aims to explore the impact of ICD development in colorectal cancer treatment and investigate the potential of ICD inducers in colorectal cancer immunotherapy.

Objective To investigate the effect of Liu-Shen-Wan on transplanted tumors in mice with colon cancer based on the polarization of M2 macrophages in the tumor microenvironment. Methods We established a subcutaneous transplantation tumor model of mice with CT26 colon cancer. Mice were randomly divided into vehicle, oxaliplatin, and oxaliplatin combined with Liu-Shen-Wan groups. Treatment was administered for three weeks, and tumor volume was measured. All mice were weighed during the administration. After the end of the treatment, the mice were dissected and tumors were photographed and weighed. Spleen index was calculated. The expression levels of IFN-γ and IL-12P40 in serum and related blood biochemical indices were measured. The expression levels of M2 macrophage polarization indices, namely, IL-10 and TGF-β, in serum and tumor tissues were detected. The infiltration degree of M2 macrophages in each group was observed by immunohistochemical experiments. Results The tumor volume and mouse weight in the oxaliplatin combined with Liu-Shen-Wan group significantly decreased compared with those in the vehicle group. The spleen index increased, and the expression levels of IFN-γ and IL-12P40 in serum also significantly increased. The mice had no obvious side effects after the drug treatment. In addition, the expression levels of IL-10 and TGF-β in the serum and tissues of mice in the oxaliplatin combined with Liu-Shen-Wan group significantly decreased. The expression levels of CD68 and CD206 in tumor tissues also decreased. Conclusion The anti-tumor effect of Liu-Shen-Wan on the transplanted tumors of mice with colon cancer is related to the inhibition of M2 macrophage polarization in the tumor microenvironment.

Objective To compare expression of Toll?like receptors 7 and 9(TLR7, TLR9)as well as their regulatory molecules myeloid differentiation factor 88(MyD88)and nuclear factor?κB(NF?κB)in peripheral blood mononuclear cells(PBMCs)between patients with vitiligo and healthy individuals, and to explore their significance. Methods Flow cytometry was performed to measure expression of TLR7 and TLR9 in PBMCs among 36 patients with vitiligo and 22 healthy controls, and real?time fluorescence?based quantitative PCR(RT?PCR)was conducted to determine mRNA expression of MyD88 and NF?κB in the above blood samples. Results Compared with healthy controls, patients with vitiligo showed higher expression of TLR7 and mRNA expression of MyD88 and NF?κB, but lower expression of TLR9. However, significant differences were only observed in the mRNA expression of NF?κB(t=2.814, P=0.008), but not in the expression of TLR7 and TLR9 or the mRNA expression of MyD88 between patients and controls (t = 1.477, 1.761, 0.058, all P > 0.05). Conclusion NF?κB, as a key signaling molecule of TLR7 and TLR9 regulation pathways, increases obviously in patients with vitiligo, suggesting that NF?κB may be involved in the pathogenesis of vitiligo.

Objective To prepare quercetin ( QUE) loaded chitosan nanoparticles ( CS-NPs), evaluate its physicochemical properties and antioxidation activity in vitro.Methods Quercetin chitosan nanoparticles were prepared by ionic crosslinking method and self-assembly method.The preparation method was optimized using entrapment efficiency (EE), drug loading (DL) and size as indexes.The best formulation and preparation conditions were optimized by orthogonal test based on single-factor test, evaluation indicator as particle size and EE.The physicochemical properties of the obtained QUE-CS-NPs were characterized by the following methods: the transmission electron microscope (TEM), dynamic light scattering (DLS) analysis for morphology, size distribution and Zeta potential.In vitro release behavior in 0.5% SDS solution was evaluated by dialysis tube method.In vitro antioxidant activity assays were performed by evaluating the abilities of the microspheres for hydroxide radicals and superoxide anions .Results TEM results revealed QUE-CS-NPs with round and uniform.Particle-size analysis showed that the diameters and Zeta potential of the QUE-CS-NPs were (282.9 ±20) nm and (30.5 ±2) mV, with uniform distribution (polydispersity below 0.185).DL and EE of QUE-CS-NPs were (8.81 ±0.65) %and (80.02 ±1.04) %, respectively.QUE-CS-NPs showed extended administration times with 66.2% cumulative release within 72 h.QUE-CS-NPs showed pronounced antioxidant activity and a concentration dependent, even more substantial than that of pure QUE.Conclusion QUE-CS-NPs show a good size, sustain release effect and pronounce antioxidant activity.

Objective:To prepare the site-specific biotinylation of enhanced green fluorescence protein with double biotin molecules using Avi-tag technology.Methods:The EGFP gene was prepared by PCR and cloned into pdi-Avitag resulting the vector pEGFP-( Avitag) 2.The fusion protein EGFP-( Avitag ) 2 was expressed in E.coli DH5αand purified by employing IMAC.The site-specific biotinylation was implemented by BirA enzyme in vitro, and then was identified by competitive ELISA and Western blot.Results:The recombinant prokaryotic expression vector pEGFP-(Avitag)2 was correctly constructed,and EGFP-(Avitag)2 fusion was successfully expressed in E.coli DH5α.The results of competitive ELISA and Western blot showed that the EGFP-( Avitag) 2 could be site-specific biotinylation with double biotin molecules based on Avi-tag technology.Conclusion: The site-specific biotinylation of EGFP with double biotin molecules is successfully prepared,and we anticipate that can be used for BAS to improve the sensitivity and specificity of immunosensors.

Objective:To construct and express the fusion protein between ZZ affinity peptide and alkaline phosphatase and examine its biological activities.Methods:The alkaline phosphatase gene was cloned into pEZZ 18 vector containing ZZ peptide gene resulted in the pEZZ-AP recombinant vector.Then the vector was transformed and expressed in E.coli DH5α.And HisTrap affinity chromatography was employed to separate and purify the target protein.After analyzed by Western blot , ZZ-AP fusion protein was applied to immunocytochemistry as an alterative second antibody.Results:The result of SDS-PAGE showed that the fusion protein with a relative molecular weight was consistent with the theoretical values (62 kD).The fusion protein has rabbit IgG-binding ability and en-zymatic activity of alkaline phosphatase ,those were validated in Western blot;and it produced a good signal that was comparable in its staining pattern to that generated with goat anti-rabbit IgG-AP in immunocytochemistry.Conclusion: The ZZ-AP fusion protein was constructed successfully ,it has rabbit IgG-binding ability and enzymatic activity of alkaline phosphatase.We anticipate that the ZZ-AP fusion protein has a potential application in immunoassay field.