• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.47-59
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• 2023

Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4⁺ and CD8⁺ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4⁺ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8⁺ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4⁺ T-cell early priming.

• BMB Reports
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• v.30 no.6
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• pp.415-420
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• 1997

Although $CD4^+$ T cell responses to protein-derived antigen have well been understood, the epitopes recognized by hapten-specific $CD4^+$ T cells have not been fully defined. In this study, we characterized the response of a T cell hybridoma (5Di0.1B8) which is specific for a hapten. N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) restricted by MHC class II $I-A^d$. Using three different antigen presenting cells (APCs) expressing $I-A^d$, the role of class II MHC proteins in haptenic antigen presentation and subsequent activation of 5D10.1B8 has been examined. Activation of 5D10.1B8 T cells by HSAB analogs was also performed. Our results show that each APC activated T cells differentially and that interleukin-2 (IL-2) augmented antigen-presenting ability of all the APCs, suggesting that increased expression of class II MHC protein by IL-2 played an important role in HSAB presentation and T cell activation. Finally, early T cell receptor-dependent signals induced by HSAB or its analogs were examined by phosphotyrosine immunoblot analysis, and showed that tyrosine phosphorylation level of a 18-20 kD protein increased upon stimulation.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.62-64
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• 2008

A major hurdle to the development of RNA interference as therapy for HIV infection is the delivery of siRNA to T lymphocytes which are difficult cells to transfect even in vitro. We have employed a single chain antibody to the pan T cell surface antigen CD7 was conjugated to an oligo-9-arginine peptide (scFvCD7-9R) for T cell-specific siRNA delivery in NOD/SCIDIL2${\gamma}$-/- mice reconstituted with human peripheral blood lymphocytes (Hu-PBL). Using a novel delivery, we first show that scFvCD7-9R efficiently delivered CD4 siRNA into human T cells in vitro. In vivo administration to Hu-PBL mice resulted in reduced levels of surface CD4 expression on T cells. Mice infected with HIV-1 and treated on a weekly basis with scFvCD7-9R-siRNA complexes targeting a combination of viral genes and the host coreceptor molecule CCR5 successfully maintained CD4/CD3 T cell ratios up to 4 weeks after infection in contrast to control mice that displayed a marked reduction in CD4 T cell numbers. p24 antigen levels were undetectable in 3 of the 4 protected mice. scFvCD7-9R/antiviral siRNA treatment also helped maintain CD4 T cell numbers with reduced plasma viral loads in Hu-PBL mice reconstituted with PBMC from donors seropositive for HIV, indicating that this method can contain viral replication even in established HIV infections. Our results show that scFvCD7-9R could be further developed as a potential therapeutic for HIV-1 infection.

• IMMUNE NETWORK
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• v.16 no.1
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• pp.33-43
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• 2016

Cell-penetrating peptides (CPPs) are short amino acids that have been widely used to deliver macromolecules such as proteins, peptides, DNA, or RNA, to control cellular behavior for therapeutic purposes. CPPs have been used to treat immunological diseases through the delivery of immune modulatory molecules in vivo. Their intracellular delivery efficiency is highly synergistic with the cellular characteristics of the dendritic cells (DCs), which actively uptake foreign antigens. DC-based vaccines are primarily generated by pulsing DCs ex vivo with various immunomodulatory antigens. CPP conjugation to antigens would increase DC uptake as well as antigen processing and presentation on both MHC class II and MHC class I molecules, leading to antigen specific CD4⁺ and CD8⁺ T cell responses. CPP-antigen based DC vaccination is considered a promising tool for cancer immunotherapy due to the enhanced CTL response. In this review, we discuss the various applications of CPPs in immune modulation and DC vaccination, and highlight the advantages and limitations of the current CPP-based DC vaccination.

• IMMUNE NETWORK
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• v.4 no.1
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• pp.38-43
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• 2004

Backgroud: Immunotherapy using dendritic cells (DC) loaded with tumor antigens may represent a potentially effective method for inducing antitumor immunity. We evaluated the effectiveness of DC-based antitumor immune response in various conditions. Methods: DC were cultured from peripheral blood mononuclear cells (PBMNC) in myelogenous leukemia (ML) and lysates of autologous leukemic cells are used as tumor antigen. The effectiveness of interleukin-12 (IL-12) and CD40L (CD154) on the antigen presenting function of lysates-loaded DC was analyzed by proliferation, cytokine production, and cytotoxicity tests with activated PBMNC (mainly lymphocytes). For generating antigen-loaded DC, direct fusion of DC with ML was studied. Results: Antigen loaded DC induced significantly effective antitumor immune response against autologous leukemic cells. Administration of IL-12 on the DC based antitumor immune response showed higher proliferation activity, IFN-$\gamma$ production, and cytotoxic activity of PBMNC. Also, fused cell has a potent antitumor immune response. Conclusion: We conclude that lysates-loaded DC with IL-12 may be effectively utilized as inducer of antitumor immune reaction in ML and in vivo application with DC-based antitumor immunotherapy or tumor vaccination seems to be feasible.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.900-903
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• 2012

Cadmium is known to be very toxic to human health and can be relative easily translocated from soils in plants. Therefore, a rapid method for screening Cd in soils and crops has become more and more important. For this reason, we examined a rapid immunochromatograpy (ICG) test kit which uses antigen-antibody reaction based on immunoassay and chromatography. Soils and rice grains collected from mine waste-contaminated sites were determined for their Cd contents using this kit. For comparison purposes, 0.1 M HCl and ICP-OES were employed as a conventional extraction and determination method. Cadmium contents in rice grains determined using ICG technique were $0.46{\sim}2.39mg\;kg^{-1}$ and Cd contents determined using 0.1 M HCl and ICP-OES were $0.52{\sim}1.97mg\;kg^{-1}$. The correlation between these two Cd contents were statistically significant ($r^2$=0.930). The results of Cd contents in soils also showed a statistically significant relationship between these two methods ($r^2$=0.975). On the basis of these results, ICG technique can be applied to rapidly quantify Cd in crops and soils. However, further research is necessary to apply ICG technique for the field screening.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.175-180
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• 2007

To evaluate whether there is a relation between Korean red ginseng (KRG)-intake and the suppression of immune hyperactivation in HIV-1-infected patients, we measured serum soluble CD8 (sCD8) over 31-48 months in 168 patients. They were divided into four groups; HIV-1-infected control (n = 49), zidovudine (ZDV) group (n = 22), KRG group (n = 48), and combination of KRG and ZDV group (n = 49). In control, sCD8 and the ratio of sCD8/CD8+ T cells significantly increased by 33% (paired t-test, P < 0.05) and 54% over $21\;{\pm}\;13$ months (P < 0.001), respectively. In ZDV group, sCD8 decreased within first 6 months and then showed steady increase and the ratio also increased over $19\;{\pm}\;10$ months. In KRG group, sCD8 and the ratio of sCD/CD8+ T cells continuously decreased by 45% (P < 0.01) and 19% over $19\;{\pm}\;11$ months (P < 0.05), respectively. In combination group, sCD8 gradually decreased by 29% (P < 0.01). There was a clear difference in the changes in serum sCD8 over time among 4 groups. There was no rebound phenomenon in KRG group as shown in ZDV group. These results suggest that KRG-intake suppresses immune hyperactivation state by HIV antigen itself in the HIV-infected patients.

• Molecules and Cells
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• v.37 no.5
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• pp.365-371
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• 2014

Recent findings, notably on adipokines and adipose tissue inflammation, have revised the concept of adipose tissues being a mere storage depot for body energy. Instead, adipose tissues are emerging as endocrine and immunologically active organs with multiple effects on the regulation of systemic energy homeostasis. Notably, compared with other metabolic organs such as liver and muscle, various inflammatory responses are dynamically regulated in adipose tissues and most of the immune cells in adipose tissues are involved in obesity-mediated metabolic complications, including insulin resistance. Here, we summarize recent findings on the key roles of innate (neutrophils, macrophages, mast cells, eosinophils) and adaptive (regulatory T cells, type 1 helper T cells, CD8 T cells, B cells) immune cells in adipose tissue inflammation and metabolic dysregulation in obesity. In particular, the roles of natural killer T cells, one type of innate lymphocyte, in adipose tissue inflammation will be discussed. Finally, a new role of adipocytes as antigen presenting cells to modulate T cell activity and subsequent adipose tissue inflammation will be proposed.

• IMMUNE NETWORK
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• v.12 no.6
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• pp.277-283
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• 2012

Vitamin C is an essential water-soluble nutrient which primarily exerts its effect on host defense mechanisms and immune homeostasis, but the mechanism related to immune-potentiation is poorly understood. Since dendritic cells (DCs) are known as a potent antigen presenting cell (APC) that could enhance the antigen specific immune responses, we investigate the effects of vitamin C on activation of DCs and its related mechanism by using dendritic cell lines, DC-1. First, we found that there was no damage on DC-1 by 2.5 mM of vitamin C. In the presence of vitamin C, the expression of CD80, CD86, and MHC molecules was increased, but it was decreased by the pre-treatment of SB203580, p38 MAPK-specific inhibitor. We confirmed the phosphorylation of p38 MAPK was increased by the treatment of vitamin C. Taken together, these results suggest that vitamin C could enhance the activity of dendritic cells via the up-regulation of the expression of CD80, CD86, and MHC molecules and the activation of p38 MAPK is related to this process.

• Animal cells and systems
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• v.8 no.2
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• pp.125-133
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• 2004

We have extended our previous work that cross-linking CD4 molecules using specific MAb induced antigen nonspecific, MHC unrestricted killing of virally infected target cells by CD$4^+$We have extended our previous work that cross-linking CD$4^+$ molecules using specific MAb induced antigen nonspecific, MHC unrestricted killing of virally infected target cells by CD$4^+$ T cells. The killing activity of antibody activated CD$4^+$T cells was completely blocked by herbimycin A, a protein tyrosine kinase (PTK) inhibitor, but not by bisindolylamaleimide, a protein kinase C (PKC) inhibitor. Herbimycin A treated human or bovine peripheral blood CD$4^+$T cells lacked PTK activity and failed to kill virally infected target cells even after cross-linking of CD4 molecules. The CD$4^+$cross-linking failed to induce effector cell proliferation or the transcription of TNF${\beta}$ Upregulation of TNF${\beta}$ was induced by incubating the antibody activated effector cells with BHV-1 infected D17 target cells for 10 h. Anti-TNF${\beta}$ antibody partially abolished (13-44%) the direct effector cell-mediated antiviral cytotoxicity. However, this antibody neutralized 70 to 100% of antiviral activity of effector and target cell culture supernatants against BHV-1 infected D17 cells. The inhibition level of the antiviral activity by the antibody was dependent on the effector and target cell ratio. These results support the hypothesis that increased p$56^ICK enzyme activity in effector cells transduces a signal critical for effector cell recognition of viral glycoproteins expressed on the target cells. Following target cell recognition, lytic cytokines known to participate in target cell killing were produced. A better understanding of the killing activity displayed by CD$4^+$T lymphocytes following surface receptor cross-linking will provide insight into the mechanisms of cytotoxic activity directed toward virally-infected cells.T cells. The killing activity of antibody activated CD$4^+$T cells was completely blocked by herbimycin A, a protein tyrosine kinase (PTK) inhibitor, but not by bisindolylamaleimide, a protein kinase C (PKC) inhibitor. Herbimycin A treated human or bovine peripheral blood CD4T cells lacked PTK activity and failed to kill virally infected target cells even after cross-linking of CD4molecules. The CD4 cross-linking failed to induce effector cell proliferation or the transcription of TNF$\beta$. Upregulation of TNF$\beta$ was induced by incubating the antibody activated effector cells with BHV-1 infected D17 target cells for 10 h. Anti-TNF$\beta$ antibody partially abolished (13-44%) the direct effector cell-mediated antiviral cytotoxicity. However, this antibody neutralized 70 to 100% of antiviral activity of effector and target cell culture supernatants against BHV-1 infected D17 cells. The inhibition level of the antiviral activity by the antibody was dependent on the effector and target cell ratio. These results support the hypothesis that increased $56^ICK enzyme activity in effector cells transduces a signal critical for effector cell recognition of viral glycoproteins expressed on the target cells. Following target cell recognition, lytic cytokines known to participate in target cell killing were produced. A better understanding of the killing activity displayed by CD$4^+$T lymphocytes following surface receptor cross-linking will provide insight into the mechanisms of cytotoxic activity directed toward virally-infected cells.