• YAKHAK HOEJI
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• v.52 no.6
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• pp.494-499
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• 2008

The role of antibody in the fungal infections is controversial. However, our previous reports showed a certain epitope in Candida albicans cell wall (CACW) induces protective antibody. A major problem is that the epitope isolation requires tremendous time with high cost. This aspect led us to investigate a simple way inducing protective antibodies against C. albicans. In the present study, we determined if $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glabrae Radix (a family of Leguminosae) has immunoadjuvant activity. Data displayed that the $18{\beta}$-GA suppressed proliferations of both T- and Blymphocytes at high concentrations, whereas below 20 ${\mu}M$ concentration the compound supported the proliferations. These observations indicate that $18{\beta}$-GA has immunoregulatory activity. Based on this observation, an immunoadjuvant effect was examined at the low concentration. Results from animal experiments showed that CACW combined with or without $18{\beta}$-GA produced the anti-C. albicans antiserum in mice. Nevertheless, the CACW combined with $18{\beta}$-GA formula only protected mice against disseminated candidiasis (P<0.05). These data implicate that $18{\beta}$-GA has immunoadjuvant activity, which may provoke the CACW antigen to induce protective antibody. Currently, we are investigating possible mechanism of how the $18{\beta}$-GA provokes such protective immunity against the disseminated disease.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.211-217
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• 2020

Molecular mimicry is the most common mechanism that breaches self-tolerance. We previously identified autoantibodies to aquaporin-5 (AQP5) in the sera of patients with Sjögren's syndrome and found that the aquaporin of Prevotella melaninogenica (PmAqp), an oral commensal, is highly homologous to human AQP5. This study aimed to test whether PmAqp can induce anti-AQP5 autoantibodies via molecular mimicry. From the amino acid sequence of PmAqp, an immunizing peptide; i.e., PmE-L, was designed, which contained both the B cell epitope "E" and T cell epitope. C57BL/6 and BALB/c mice were subcutaneously immunized with linear or cyclic forms of PmE-L emulsified in incomplete Freund's adjuvant. The concentrations of the antibodies in sera were measured using enzyme-linked immunosorbent assays. Both linear and cyclic PmE-L induced high levels of antibodies against not only the immunized peptides but also autoantibodies against AQP5E and antibodies against PmE, a Pm homolog of AQP5E. In C57BL/6 mice; however, the cyclic form of PmE-L was more efficient than the linear form in inducing autoantibodies against AQP5E that contained a cyclic epitope. The levels of anti-PmE antibodies and anti-AQP5E autoantibodies showed a strong positive correlation (r = 0.95, p < 0.0005), suggesting molecular mimicry. Collectively, the mice produced anti-AQP5E autoantibodies in response to a PmAqp-derived peptide. This model proved to be useful for studying the mechanisms of autoantibody production by molecular mimicry.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.468-472
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• 2003

Recently, genetic engineering techniques have been used to display various heterologous peptides and proteins (enzyme, antibody, antigen, receptor and fluorescence protein, etc.) on the yeast cell surface. Living cells displaying various enzymes on their surface could be used repeatedly as 'whole cell biocatalysts' like immobilized enzymes. We constructed a yeast based whole cell biocatalyst displaying T. reesei cellobiohydrolase I (CBH I ) on the cell surface and endowed the yeast-cells with the ability to degrade cellulose. By using a cell surface engineering system based on ${\alpha}-agglutinin,$ CBH I was displayed on the cell surface as a fusion protein containing the N-terminal leader peptide encoding a Gly-Ser linker and the $Xpress^{TM}$ epitope. Localization of the fusion protein on the cell surface was confirmed by confocal microscopy. In this study, we report on the genetic immobilization of T. reesei CBH I on the S. cerevisiae and hydrolytic activity of cell surface displayed CBH I.

• IMMUNE NETWORK
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• v.22 no.5
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• pp.42.1-42.20
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• 2022

Vaccination with tumor peptide epitopes associated with MHC class I molecules is an attractive approach directed at inducing tumor-specific CTLs. However, challenges remain in improving the therapeutic efficacy of peptide epitope vaccines, including the low immunogenicity of peptide epitopes and insufficient stimulation of innate immune components in vivo. To overcome this, we aimed to develop and test an innovative strategy that elicits potent CTL responses against tumor epitopes. The essential feature of this strategy is vaccination using tumor epitope-loaded nanoparticles (NPs) in combination with polyinosinic-polycytidylic acid (poly-IC) and anti-PD1 mAb. Carboxylated NPs were prepared using poly(lactic-co-glycolic acid) and poly(ethylene/maleic anhydride), covalently conjugated with anti-H-2K^b mAbs, and then attached to H-2K^b molecules isolated from the tumor mass (H-2^b). Native peptides associated with the H-2K^b molecules of H-2K^b-attached NPs were exchanged with tumor peptide epitopes. Tumor peptide epitope-loaded NPs efficiently induced tumor-specific CTLs when used to immunize tumor-bearing mice as well as normal mice. This activity of the NPs significantly was increased when co-administered with poly-IC. Accordingly, the NPs exerted significant anti-tumor effects in mice implanted with EG7-OVA thymoma or B16-F10 melanoma, and the anti-tumor activity of the NPs was significantly increased when applied in combination with poly-IC. The most potent anti-tumor activity was observed when the NPs were co-administered with both poly-IC and anti-PD1 mAb. Immunization with tumor epitope-loaded NPs in combination with poly-IC and anti-PD1 mAb in tumor-bearing mice can be a powerful means to induce tumor-specific CTLs with therapeutic anti-tumor activity.

• BMB Reports
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• v.47 no.7
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• pp.399-404
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• 2014

B7-H4 is a member of B7 family of co-inhibitory molecules and B7-H4 protein is found to be overexpressed in many human cancers and which is usually associated with poor survival. In this study, we developed a therapeutic vaccine made from a fusion protein composed of a tetanus toxoid (TT) T-helper cell epitope and human B7-H4IgV domain (TT-rhB7-H4IgV). We investigated the anti-tumor effect of the TT-rhB7-H4IgV vaccine in BALB/c mice and SP2/0 myeloma growth was significantly suppressed in mice. The TT-rhB7-H4IgV vaccine induced high-titer specific antibodies in mice. Further, the antibodies induced by TT-rhB7-H4IgV vaccine were capable of depleting SP2/0 cells through complement-dependent cytotoxicity (CDC) in vitro. On the other hand, the poor cellular immune response was irrelevant to the therapeutic efficacy. These results indicate that the recombinant TT-rhB7-H4IgV vaccine might be a useful candidate of immunotherapy for the treatment of some tumors associated with abnormal expression of B7-H4.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.137-143
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• 1997

Porcine transforming growth factor-$\beta$1 (TGF-$\beta$1) was expressed in Escherichia coli using cDNA of TGF-$\beta$1 and glutathione S-transferase (GST) fusion vector pGEX-1$\lambda$T. An ApoI-Tth111I fragment of cDNA which correspond to the amino acid residues from 123 to 390 of the precursor TGF-$\beta$1 was inserted into EcoRI-Tth111I digested pGEM#-l$\lambda$T and the recombined plasmid was named pGET-12. Gene products from the cloned regions of the recombinant plasmids pGET-12 was not detected in soluble fraction of cell free extract but detected in insoluble fraction. The solubilization of insoluble gene product was achieved by the treatment of N-laurylsarcosine. Molecular weight of partially purified proteins determined by electrophoresis was same as expected from cloned fragment. The ELISA test results of the purified proteins showed that immunologically detectable epitope was preserved in recombinant protein.

• IMMUNE NETWORK
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• v.3 no.3
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• pp.235-241
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• 2003

Background: The protective immunity against tuberculosis (TB) involves both CD4+ T cells and CD8+ T cells. In our previous study, we defined four Mycobacterium tuberculosis derived peptide epitopes specific for HLA-$A^*0201$ restricted CD8+ T cells ($ThyA_{30-38}$, $RpoB_{127-135}$, $85B_{15-23}$, $PstA1_{75-83}$). In this study, we investigated the immune responses induced by these peptide specific CD8+ T cells in latently and chronically infected people with TB. Methods: We characterized these peptide specific CD8+ T cell population present in PBMC of both TB patients and PPD+healthy people using IFN-${\gamma}$elispot assay, intracellular staining and HLA-A2 dimer staining. Results: The frequency of peptide specific CD8+ T cell was in the range of 1 to 25 in $1.7{\times}10^5$ PBMC based on ex vivo IFN-${\gamma}$ elispot assay, demonstrating that these peptide specific CD8+ T cell responses are induced in both TB patients and PPD+ people. Short term cell lines (STCL) specific for these peptides proliferated in vitro and secreted IFN-${\gamma}$ upon antigenic stimulation in PPD+ donors. Lastly, HLA-$A^*0201$ dimer assays indicated that $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors is heterogeneous since approximately 25~33% of $PstA1_{75-83}$ specific CD8+ T cell population in PPD+ healthy donors produced IFN-${\gamma}$ upon peptide stimulation. Conclusion: Our results suggest that MHC class I restricted CD8+ T cell mediated immune responses to M. tuberculosis infection are induced in both TB patients and PPD + people; however, the CD8+ T cell population is functionally heterogeneous.

• BMB Reports
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• v.45 no.7
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• pp.408-413
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• 2012

Almost all melanoma cells express at least one member of the MAGE-A antigen family, making the cytotoxic T cells (CTLs) epitopes with cross-immunizing potential in this family attractive candidates for the broad spectrum of anti-melanoma immunotherapy. In this study, four highly homologous peptides (P264: FLWGPRALA, P264I9: FLWGPRALI, P264V9: FLWGPRALV, and P264H8: FLWGPRAHA) from the MAGE-A antigens were selected by homologous alignment. All four peptides showed high binding affinity and stability to HLA-A$^*02:01$ molecules, and could prime CTL immune responses in human PBMCs and in HLA-A$^*02:01/K^b$ transgenic mice. CTLs elicited by the four epitope peptides could cross-lyse tumor cells expressing the mutual target antigens, except MAGE-A11 which was not tested. However, CTLs induced by P264V9 and P264I9 showed the strongest target cell lysis capabilities, suggesting both peptides may represent the common CTL epitopes shared by the eight MAGE-A antigens, which could induce more potent and broad-spectrum antitumor responses in immunotherapy.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.61-68
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• 2010

Purpose: The present study was performed to clarify the relationship between periodontal disease severity and selected immunological parameters consisting of serum IgG titer against periodontopathogenic bacteria, the expression of the helper T-cell cytokine by gingival mononuclear cells, and patients' immunoreactivity to cross-reactive heat shock protein (HSP) epitope peptide from P. gingivalis HSP60. Methods: Twenty-five patients with moderate periodontitis had their gingival connective tissue harvested of gingival mononuclear cells during an open flap debridement procedure and peripheral blood was drawn by venipuncture to collect serum. The mean level of interproximal alveolar bone was calculated to be used as an index for periodontal disease severity for a given patient. Each of selected immunologic parameters was subject to statistical management to seek their correlations with the severity of periodontal disease. Results: A significant correlation could not be identified between serum IgG titers against specific bacteria (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, and Streptococcus mutans) and the severity of periodontal disease. Expression of interleukin (IL)-10 by gingival mononuclear cells was statistically significant in the group of patients who had higher levels of alveolar bone height. However, a similar correlation could not be demonstrated in cases for IL-4 or interferon-$\gamma$. Patients' serum reactivity to cross-reactive epitope peptide showed a significant correlation with the amount of alveolar bone. Conclusions: It was concluded that expression of IL-10 by gingival mononuclear cells and patients' sero-reactivity to the cross-reactive HSP peptide of P. gingivalis HSP60 were significantly correlated with alveolar bone height.

• Reproductive and Developmental Biology
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• v.35 no.4
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• pp.511-518
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• 2011

To avoid hyperacute rejection of xenografts, ${\alpha}1,3$-galactosyltransferase knock-out (GalT KO) pigs have been produced. In this study, we examined whether Sia-containing glycoconjugates are important as an immunogenic non-Gal epitope in the pig liver with disruption of ${\alpha}1,3$-galactosyltransferase gene. The target cells were then used as donor cells for somatic cell nuclear transfer (scNT). A total of 1,800 scNT embryos were transferred to 10 recipients. One recipient developed to term and naturally delivered two piglets. Real-time RT-PCR and glycosyltransferase activity showed that ${\alpha}2,3$-sialyltransferase (${\alpha}2,3ST$) and ${\alpha}2,6$-sialyltransferase (${\alpha}2,6ST$) in the heterozygote GalT KO liver have higher expression levels and activities compared to controls, respectively. According to lectin blotting, sialic acidcontaining glycoconjugate epitopes were also increased due to the decreasing of ${\alpha}$-Gal in heterozygote GalT KO liver, whereas GalNAc-containing glycoconjugate epitopes were decreased in heterozygote GalT KO liver compare to the control. Furthermore, the heterozygote GalT KO liver showed a higher Neu5Gc content than control. Taken together, these finding suggested that the deficiency of GalT gene in pigs resulted in increased production of Neu5Gc-bounded epitopes (H-D antigen) due to increase of ${\alpha}2,6$-sialyltransferase. Thus, this finding suggested that the deletion of CMAH gene to the GalT KO background is expected to further prolong xenograft survival.