• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4037-4043
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• 2012

Despite progress in elucidating mechanisms associated with colorectal cancer and improvement of treatment methods, it remains a frequent cause of death worldwide. New and more effective therapies are therefore urgently needed. Recent studies have shown that immunogenicity of whole ovarian tumor cells and subsequent T cell response were potentiated by oxidation modification with hypochlorous acid (HOCl) in vitro and ex vivo. These results prompted us to investigate the protective antitumor response with an HOCl treated CT26 colorectal cancer cell vaccine in an in vivo mouse model. Administration of HOCl modified vaccine triggered robust antitumor immunity to autologous tumor cells in mice and prolonged survival period significantly. In addition, increased necrosis and apoptosis were found in tumor tissue from the oxidation group. Interestingly, ELISPOT assays showed that specific T cell responses were not elicited in response to the immunizing cellular antigen, in contrast to raising sera antibody titer and antibody binding activity shown by ELISA assay and flow cytometry. Further evaluation of the mechanisms underlying HOCl modified vaccine mediated humoral immunity highlighted the role of antibody-dependent cell-mediated cytotoxicity. These results combined with previous studies suggest that HOCl oxidation modified whole cell vaccine has wide applicability as a cancer vaccine because it can target both T cell- and B cell-specific responses. It may thus represent a promising approach for the immunotherapy of colorectal cancer.

• International Journal of Oral Biology
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• v.42 no.2
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• pp.63-70
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• 2017

Selecting an appropriate antigen with optimal immunogenicity and physicochemical properties is a pivotal factor to develop a protein based subunit vaccine. Despite rapid progress in modern molecular cloning and recombinant protein technology, there remains a huge challenge for purifying and using protein antigens rich in hydrophobic domains, such as membrane associated proteins. To overcome current limitations using hydrophobic proteins as vaccine antigens, we adopted in silico analyses which included bioinformatic prediction and sequence-based protein 3D structure modeling, to develop a novel periodontitis subunit vaccine against the outer membrane protein FomA of Fusobacterium nucleatum. To generate an optimal antigen candidate, we predicted hydrophilicity and B cell epitope parameter by querying to web-based databases, and designed a truncated FomA (tFomA) candidate with better solubility and preserved B cell epitopes. The truncated recombinant protein was engineered to expose epitopes on the surface through simulating amino acid sequence-based 3D folding in aqueous environment. The recombinant tFomA was further expressed and purified, and its immunological properties were evaluated. In the mice intranasal vaccination study, tFomA significantly induced antigen-specific IgG and sIgA responses in both systemic and oral-mucosal compartments, respectively. Our results testify that intelligent in silico designing of antigens provide amenable vaccine epitopes from hard-to-manufacture hydrophobic domain rich microbial antigens.

• IMMUNE NETWORK
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• v.4 no.1
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• pp.31-37
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• 2004

Background: 1-8D gene is a member of human 1-8 interferon inducible gene family and is shown to be overexpressed in fresh colon cancer tissues. Three peptides 1-6, 3-5 and 3-7 derived from 1-8D gene were shown to have immunogenicity against colon cancer. Methods: To study tumor immunotherapy of these peptides we established an adoptive transfer model. $D^{b-/-}{\times}{\beta}2$ microglobulin (${\beta}2m$) null mice transgenic for a chimeric HLA-A2.1/$D^b-{\beta}2m$ single chain (HHD mice) were immunized with irradiated peptide-loaded RMA-S/HHD/B7.1 transfectants. Spleens were removed after last immunization, and splenocytes were re-stimulated in vitro. Lymphocytes from vaccinated HHD mice were transferred together with IL-2 to the tumor bearing nude mice that were challenged S.C. with the HCT/HHD/B7 colon carcinoma cell line that was found to grow in these mice. Results: Peptide 3-5 was found to be highly effective in CTL activity. Adoptively transferred anti-peptide 3-5 cytolytic T lymphocytes caused significant retardation in tumor growth. Conclusion: This study shows that peptide 3-5 can be the most effective candidate for the vaccine of adoptive immunotherapy against colon cancer.

• Biomedical Science Letters
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• v.23 no.3
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• pp.175-184
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• 2017

Cholera toxin (CT) is an ADP-ribosylating bacterial exotoxin that has been used as an adjuvant in animal studies of oral immunization. The mechanisms of mucosal immunogenicity and adjuvanticity of CT remain to be established. In this study, we investigated the role of indoleamine 2,3-dioxygenase (IDO), which participates in the induction of immune tolerance, in CT-mediated breakdown of oral tolerance. When IDO-deficient ($IDO^{-/-}$) mice and their littermates were given oral ovalbumin, significant changes in antibody responses, footpad swelling and $CD4^+$ T cell proliferation were not observed in $IDO^{-/-}$ mice. Feeding of CT decreased IDO expression in mesenteric lymph nodes (MLN) and Peyer's patch (PP). CT-induced downregulation of IDO expression was reversed by inhibitors of nuclear factor-kappa B (NF-${\kappa}B$), pyrrolidine dithiocarbamate and p50 small interfering RNA. IDO expression was downregulated by the NF-${\kappa}B$ inducers lipopolysaccharide and tumor necrosis factor-${\alpha}$. CT dampened IDO activity and mRNA expression in dendritic cells from MLN and PP. These data indicate that CT disrupts oral tolerance by activating NF-${\kappa}B$, which in turn downregulates IDO expression. This study betters the understanding of the molecular mechanism underlying CT-mediated abrogation of oral tolerance.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.9-15
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• 2017

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a ${\beta}-lactamase$ secretion system. This was then transformed into ${\Delta}asd$ ${\Delta}crp$ Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1173-1181
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• 1996

The causes of degenerative changes in allograft cardiac valves are not well known to this day. Today's preserved allografts possess highly viable endothelial cells and degeneration of allografts can be facilitated by immune reaction which may be mediated by these viable cells. To test the antigenicity of endothelial cells, pieces from aortic wall were obtained from fresh and cryo-preserved rat allograft. Timings of sampling were prior to sterilization, after sterilization, after 1, 2, 7, 14 days of fresh preservation and cryopreservation. Endothelial cells were tested by immunohistochemical methods using monoclonal antibodies to MHC class I(MRC OX-18), class II(MRC OX-6) and ICAM-1 antigens. After transplantation of each group of aortic allograft at the subcutaneous layers of rats, population of CD4$^{+}$ T cell and CD8$^{+}$ T cell were analyzed with monoclonal antibodies after 1, 2, 3, 4, 6 and 8 weeks. MHC class I expression was 23.95% before preservation and increased to 35.53~48.08% after preservation(p=0.0183). MHC Class II expression was 9.72% before preservation and 10.13~13.39% after preservation(P=0.1599). ICAM-1 expression was 15.02% before preservation and increased to 19.85~35.33% after preservation(P=0.001). The proportion of CD4$^{+}$ T-cell was 42.13% before transplantation. And this was 49.23~36.8% after transplantation in No treat group (p=0.955), decreased to 29.56~32.80% in other group(p=0.0001~0.008). In all the groups, the proportion of CD8$^{+}$ T-cell increased from 25.57% before transplantation to 42.32~58.92% after transplantation(p=0.000l~0.0002). The CD4$^{+}$/CD8$^{+}$ ratio decreased from 1.22~2.28 at first week to 0.47~0.95 at eighth week(p=0.0001). The results revealed that the expression of MHC class I and ICAM-1 in aortic allograft endothelium were increased but that of MHC class II were not changed, despite the different method of preservation. During 8 weeks after transplantation of aortic allograft, the subpopulations of CD4$^{+}$ T cell were not changed or only slightly decreased but those of CD8$^{+}$ T cell were progressively increased.ely increased.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.23-27
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• 2012

Porcine circovirus type 2 (PCV2) is a single-stranded circular DNA virus associated with Postweaning multisystemic wasting syndrome (PMWS), which is considered to be an important infectious swine viral disease. PCV2 capsid protein encoded by ORF2 is a structural protein and expected as the high immunogenicity protein. In this study, we generated recombinant baculovirus containing ORF2 of PCV2 and analyzed the optimal conditions for the production of capsid protein in insect cell. Production and status of recombinant capsid protein in insect cell were confirmed by SDS-PAGE and Western blot analysis using His tag antibody and anti-PCV2 serum. The yield of recombinant capsid protein was high like as shown visible on SDS-PAGE. Optimal multiplicity of infection (MOI) and infection time of recombinant virus were determined as 5 MOI and 4 days, respectively. ORF2 is known to have N-linked glycosylation site, but we couldn't detect the glycosylation of recombinant protein in insect cells.

• IMMUNE NETWORK
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• v.7 no.3
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• pp.109-116
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• 2007

Background: Human papillomavirus (HPV) infection is responsible for cervical cancer, a common cancer in women. Since HPV infection and cancer development are controlled by the host immune system, immunotherapy against HPV can be helpful in preventing or treating HPV-associated cervical cancer. Two oncoproteins of HPV16, E6 and E7, are promising targets for immunotherapy against cervical cancer, because they are constitutively expressed in cervical cancer. Methods: Since cellular vaccines using B cells as well as dendritic cells offer an efficient approach to cancer immunotherapy, we opted to use B cells. We evaluated the immunogenicity and anti-tumor effects of a B cell vaccine transduced with HPV16 E6/E7-expressing adenovirus. Results: Vaccination with HPV16 E6/E7-transduced B cells induced E6/E7-specific $CD8^+$ T cell-dependent immune responses and generated anti-tumor effects against E6/E7-expressing TC-1 tumor. The anti-tumor effect induced by this B cell vaccine was similar to that elicited by DC vaccine, showing that B cells can be used as an alternative to dendritic cells for cellular vaccines. Conclusion: Thisstudy has shown the feasibility of using B cells as immunogenic APCs and the potential for developing prophylactic and therapeutic vaccines against HPV-associated cervical cancer using a B cell vaccine transduced with adenovirus expressing HPV16 E6/E7.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.157-164
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• 2018

Francisella tularensis (FT), a highly infectious pathogen, is considered to be a potential biological weapon owing to the current lack of a human vaccine against it. Tul4 and FopA, both outer membrane proteins of FT, play an important role in the bacterium's immunogenicity. In the present study, we evaluated the immune response of mice - humanized with human CD34+ cells (hu-mice) - to a cocktail of recombinant Tul4 and FopA (rTul4 and rFopA), which were codon-optimized and expressed in Escherichia coli. Not only did the cocktail-immunized hu-mice produce a significant human immunoglobulin response, they also exhibited prolonged survival against an attenuated live vaccine strain as well as human T cells in the spleen. These results suggest that the cocktail of rTul4 and rFopA had successfully induced an immune response in the hu-mice, demonstrating the potential of this mouse model for use in the evaluation of FT vaccine candidates.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.358-363
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• 2011

Background: Traditionally, interferon-${\gamma}$ (IFN-${\gamma}$) was regarded as a pro-inflammatory cytokine, however, recent reports suggested role of IFN-${\gamma}$ in immune tolerance. In our previous report, we could induce tolerance to male antigen (HY) just by male islet transplantation in wild type C57BL/6 mice without any immunological intervention. We tried to investigate the influence of IFN-${\gamma}$ deficiency on tolerance induction by male islet transplantation. Methods: To examine the immunogenicity of male tissue in the absence of IFN-${\gamma}$, we transplanted male IFN-${\gamma}$ knock-out (KO) skin to female IFN-${\gamma}$ KO mice. Next, we analyzed male IFN-${\gamma}$ KO islet to streptozotocin-induced diabetic female IFN-${\gamma}$ KO mice. And, we checked the functionality of grafted islet by graft removal and insulin staining. Results: As our previous results in wild type C57BL/6 mice, female IFN-${\gamma}$ KO mice rejected male IFN-${\gamma}$ KO skin within 29 days, and did not reject male IFN-${\gamma}$ KO islet. The maintenance of normal blood glucose level was dependent on the presence of grafted male islet. And the male islet recipient did not reject 2nd challenge of male islet graft also. Conclusion: Deficiency of IFN-${\gamma}$ does not have influence on the result of male skin graft and male islet transplantation. Conclusively, male islet transplantation induced T cell tolerance is not dependent on the presence of IFN-${\gamma}$.