N-glycosylation modification of heat shock protein gp96 affects its immunological function / 生物工程学报

N-glycosylation modification, one of the most common protein post-translational modifications, occurs in heat shock protein gp96. The purpose of this study is to investigate the effect of N-glycosylation modification on immunologic function of the recombinant gp96 using the mutant gp96 in N-glycosylation sites. Firstly, wild-type and mutant gp96 proteins were expressed by insect expression system and their glycosylation levels were detected. To determine the effect of N-glycosylation on gp96 antigen presentation function, the IFN-γ+ CD8+ T cells in gp96-immunized mice and secretion level of IFN-γ were examined by flow cytometry and ELISA. The ATPase activity of gp96 was further detected by the ATPase kit. Finally, the effect of N-glycosylation on adjuvant function of gp96 for influenza vaccine was investigated in immunized mice. It was found that total sugar content of mutant recombinant gp96 was reduced by 27.8%. Compared to the wild type recombinant gp96, mutations in N-glycosylation sites resulted in decreased antigen presentation ability and ATPase activity of gp96. Furthermore, influenza vaccine-specific T cell levels induced by mutant gp96 as adjuvant were dramatically reduced compared to those by wild type recombinant gp96. These results demonstrate that N-glycosylation modification is involved in regulation of ATPase activity and antigen presentation function of gp96, thereby affecting its adjuvant function. The results provide the technical bases for development of gp96- adjuvanted vaccines.

Effect of inhibition of heat shock protein Gp96 expression on alcoholic liver fibrosis in mice by CRISPR/Cas-9 technique / 解剖学报

Objective To investigate the effects of heat shock protein Gp96 on alcoholic liver fibrosis in mice. Methods A total of 220 male healthy C57BL/6 J mice were randomly divided into four groups; normal control group (n = 10), saline+alcohol induced liver fibrosis group (n = 70), the injection of CRISPR expression Gp96-sgRNA3 by tail vein+ alcohol induced liver fibrosis group (n = 70), the intraperitoneal injection of nuclear factor kappa B(NF-κB) inhibitors PDTC+alcohol induced liver fibrosis group (n = 70). The blood was got from eyeballs and the mice were killed after 8 weeks of ethanol induction. We detected the activity of serum aspartate aminotransferase (AST) in mice of different groups. The pathological changes were detected by HE staining, sirius red staining and periodic acid-Schiff (PAS) staining in the liver of mice. The expression of Gp96 and transforming growth factor βl ( TGF-βl ) were detected by Western blotting. Results Compared with the normal control group, the AST enzyme activity and liver fibrosis increased significantly, glycogen decreased significantly in other three groups (P<0.01). Compared with the saline+alcohol group, the AST enzyme activity and liver fibrosis increased more significantly, glycogen decreased more significantly, Gp96 expression decreased significantly and TGF-βl expression increased significantly in Gp96-sgRNA3+ alcohol group and NF-κB inhibitors PDTC+ alcohol group (P<0.01 or P<0.05). Conclusion The injection of CRISPR expression plasmid Gp96-sgRNA3 by tail vein significantly inhibited the Gp96 expression, promoted the degree of alcoholic liver fibrosis in mice, and NF-κB signaling pathway played a certain role in regulating the expression of Gp96.

CD133 epitope vaccine with gp96 as adjuvant elicits an antitumor T cell response against leukemia / 生物工程学报

Cancer stem cells are currently under intensive investigation due to their capabilities for tumor initiation, self-renewal, and resistance to chemotherapy. CD133 is implicated in stemness and the malignancy of tumor cells. Here, we explored heat shock protein gp96 adjuvanted CD133 epitope vaccine against leukemia. We screened and identified three H2-Kd-restricted cytotoxic T lymphocyte (CTL) epitopes derived from CD133, CD133₄₁₉₋₄₂₈, CD133₇₀₂₋₇₁₀ and CD133₇₆₀₋₇₆₉. The immunogenicity and antitumor activity of the epitope vaccine using heat shock protein gp96 as adjuvant were further determined in CD133⁺ leukemia xenograft mice. Finally, we demonstrate that adoptive transfer of epitope-specific CTLs led to suppression of leukemia growth. Our data therefore provide the basis for designing a CD133 epitope vaccine to activate specific CTLs against CD133⁺ leukemia and other cancers.

High-dose heat shock protein gp96 immunization prevents type 1 diabetes via inducing regulatory T cells / 生物工程学报

Type 1 diabetes (T1D), the most prevalent human autoimmune disease, occurs in genetically susceptible individuals. Regulatory T cells (Tregs) are defective in T1D setting. Therefore, efforts to repair or restore Tregs in T1D may prevent or reverse this autoimmune disease. Here, we studied the potential role of rgp96 in preventing T1D, using non-obese diabetic (NOD) mice as an animal model. High-dose rgp96 immunization elicited efficient protection of mice against T1D, as evidenced by stable blood glucose, decreased disease incidence. Significantly increased CD4⁺ CD25⁺ Foxp3⁺ Tregs were observed in immunized mice. In vitro co-culture experiments demonstrated that rgp96 stimulation enhanced Treg proliferation and suppressive function by up-regulation of Foxp3 and IL-10. Our work shows that activation of Tregs by high-dose rgp96 immunization protects against T1D via inducing regulatory T cells and provides preventive and therapeutic potential for the development of an rgp96-based vaccine against T1D.

Development of a novel method to evaluate sialylation of glycoproteins and analysis of gp96 sialylation in Hela, SW1990 and A549 cell lines

BACKGROUND: Glycoproteins play a critical role in the cellular activities of eukaryotes. Sialic acid is typically the outermost monosaccharide of glycolipids and glycoproteins, and is necessary for normal development. RESULTS: A strategy based on avidin-biotin affinity was established to enrich sialylated glycoproteins from HeLa cervical carcinoma, SW1990 pancreatic adenocarcinoma, and A549 lung adenocarcinoma cells. Using HPLC-MS/MS, western blot, real-time PCR, and enzyme-linked immunosorbent assay, gp96 was identified in all three cell lines. No significant difference in the protein expression of gp96 was detected at the whole cell level, but the amount of bioti-nylated gp96 in SW1990 cells was 30-40 % lower than that in A549 and HeLa cells, and the amount of sialylated gp96 in SW1990 cells was 30 % lower than that in A549 and HeLa cells. Immunoblotting results showed that the expression of sialyltransferase proteins in the total cell lysates from HeLa and A549 cells were higher than that in SW1990 cells. CONCLUSIONS: We established a new method for investigating the expression and sialylation of glycoproteins using metabolic labeling, click chemistry, and avidin-biotin affinity. We successfully used this method to purify sialylated glycoproteins from cancer cell lines. Our results showed that the levels of gp96 sialylation varied across different cancer cell lines, and this may be because of differences in sialyltransferase expression.

Future perspectives and challenges in the development of an antitumor vaccine based on heat shock protein gp96-peptide complex / 中国肿瘤临床

Tumor-derived heat shock protein-peptide complex 96 (HSPPC-96) containing tumor antigenic peptides can elicit po-tent tumor-specific and protective immunity. Autologous HSPPC-96 vaccine has been shown to effectively prolong recurrence-free sur-vival and increase the overall survival of many tumors, thereby suggesting extensive future applications. However, as an autologous tu-mor-derived individual vaccine, the development of HSPPC-96 vaccine is challenged by the lack of an adequate autologous tumor, lim-ited efficacy for advanced-stage cancer, etc. This paper summarized the progress, future perspectives, and challenges in the clinical de-velopment of HSPPC-96 vaccine immunotherapy.

Antibody detection against HPV16 E7 & GP96 fragments as biomarkers in cervical cancer patients.

Background & objectives: Cervical cancer is the second most frequent cancer among females worldwide, especially human papilloma viruses (HPV) types 16 and 18. In viral systems the identification of serological markers would facilitate the diagnosis of HPV infections and virus-related disease. The aim of the present investigation was to determine and search for serologic markers in cervical cancer patients associated with HPV. Methods: A total of 58 Iranian women with invasive cervical carcinoma including adenocarcinoma and squamous cell carcinoma (SCC) were included. Serum antibody response to HPV infections in patients was detected by Western blot and ELISA techniques based on recombinant HPV16E7 and the N-terminal and C-terminal fragments of gp96 (NT-gp96 and CT-gp96) proteins. These recombinant proteins were expressed in Escherichia coli as a His-tag protein and purified using affinity chromatography. Results: The ELISA results indicated that patients with high antibody response to HPV16E7 had significant seroreactivity to CT-gp96 fragment. In Western blot analysis, a strong association between anti-E7, anti-NT-gp96 and anti-CT-gp96 reactivity and cervical cancer was obtained using purified recombinant proteins. In adenocarcinoma cases, no significant difference was observed in seroreactivities between normal and patients. Interpretation & conclusions: The evaluation of cervical cancer patients' seroreactivities against three recombinant proteins (rE7, rNT-gp96 and rCT-gp96) showed significantly higher levels of these markers in SCC only, but not in adenocarcinoma and control groups. Also, the usage of both techniques (ELISA and Western blotting) can provide more reliable tools for diagnosis of cervical cancer.

Construction of human naive phage antibody library and primary screening of the gab antibodies against gp96 / 中国综合临床

Objective To construct a naive human Fab fragment phage display library,from which the anti-gp96 antibodies may be panned by the gp96 purified from the tissue of urothelial carcinoma in the urinary bladder and provide a basis to new therapy for the malignant tumors.Methods Peripheral blood lymphocytes were isolated from 800 ml of blood,which was obtained from four healthy blood donors.The heavy chain Fd and light chain cDNA synthesized from the total RNA of lympbocytes were amplified by PCR with variable regions 5' and 3' primers of heavy and light chain, and the amplification products were ligated into the phagemid vector pComb3, then the ligated sample was transformed into competent E.coli XL1-Blue by electroperation.The transformed cells were infected with VCSM13 helper phage to yield recombinant phage antibody Fabs.The phagemids abstracted from amplified E.coli were cut with endonucleases such as Sac Ⅰ,Xba Ⅰ,Xho Ⅰ and Spe Ⅰ, and both the phage antibody Fabs and phage-raids abstracted from amplified E.coil were amplified by PCR to monitor the insertion of the genes of light chain or heavy chain Fd fragment.The gp96 purified from the urothelial carcinoma tissue of the bladder by affinity chromatog-raphy on eoncanavalin-A sephnrose and DEAE-sephnrose ion exchange chromatography were utilized as antigens to process three rounds of panning to the original Fab antibody library.Results The quantity of total RNA and cDNA were qualified.By combination of light chain and heavy chain genes, an antibody library containing 6.6×106 clones was obtained, and both the cutting of enzymes and PCR showed that there were the genes of light chain or heavy chain Fd fragment in the phagemids.The gp96 protein was obtained from urothelial carcinoma tissue in the urinary bladder.After having been panned by gp96, the original antibody library gained enrichment by 68 times.Conclusion Utilizing the technology of phage surface display, specific antibody can be gained from the human naive Fab phage display library,which can be used for immunological therapy for tumors.

Gene expression of spleen lymphocytes induced by gp96-peptide complexes and its anti-tumor effect in vitro / 中国病理生理杂志

AIM:To study the expressing variation of TNF-? and IFN-? mRNA in mouse splenocytes induced by H22 tumor cells derived heat shock protein gp96-peptide complexes in vitro,and to observe the morphologic change of H22 tumor cells which treated with the culture supernatant.METHODS:H22 tumor cells derived HSP gp96 was obtained by the techniques for protein extraction and purification and was identified by Western blotting method.The expression values of TNF-? and IFN-? mRNA in spleen lymphocytes were detected by semi-quantitative RT-PCR.The morphologic changes of H22 tumor cells induced by the culture supernatant were observed by laser scanning confocal microscopy(LSCM)and transmission electron microscope(TEM).RESULTS:Purified heat shock protein gp96 was identified by Western blotting.The expression value of TNF-? and IFN-? mRNA in activated spleen lymphocytes induced by gp96-peptide complexes was higher than that in control groups(P

The Cytotoxic Effect of Peritoneal Elicited Macrophages Induced by HSPgp96 on Anti-Tumor in vitro / 中国肿瘤生物治疗杂志

Objective: To evaluate the cytotoxic effect of PEM? induced by HSPgp96 on anti-tumor in vitro. Methods; PEM? separated from mice induced by thioglycolate were divided into three groups randomly: Culture medium in control; LPS-induced group; HSPgp96-induced group. The production of NO, the cytotoxic effect to H22 cells and the morphologic change of PEM? were investigated separately by enzyme method, MTT assay and scanning electron microscope. Results: In vitro, HSPgp96 can increased NO production from PEM? of mice and significantly enhance the cytotoxic effect of PEM? to H22 cells as well as LPS. Conclusion: HSPgp96 can effectively induce the cytotoxic effect of PEM? on anti-tumor in which NO is one of the capital effective molecules in vitro.

Tumor-derived HSP gp96 induces T cell responses and its significance in tumor immunity / 中国免疫学杂志

Objective:To explore the availability for tumor-derived gp96 to induce specific CTL activity of splenocytes in vitro.Methods:gp96 purified by the techniques for protein extraction and identified by SDS-PAGE gel electrophoresis and Western blot method; CD8+T cell induced by gp96 and CTL activity detected by flow cytometry, immunofluorescence technic and CCK-8 assay.Results:gp96 was identified by SDS-PAGE and Western blot; Analysis with FCM showed that the number of CD8+T cells(nearly 70%) was obviously increased after pulsed with gp96-peptide complexes as compared with that of control groups(35%,26%, P