• Title/Summary/Keyword: Antigen presentation

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Korean Propolis enhances both the presentation of DC and macrophage activation

  • Han, Shin-Ha;Yun, Yun-Ha;Song, Young-Cheon;Lee, Sook-Yeon;Ha, Nam-Joo;Kim, Kyung-Jae
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.202.3-203
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    • 2003
  • Calcineurin inhibitors, cyclosporine A (CsA) and tacrolimus (FK506), have been studied extensively regarding their effects on T lymphocytes, but their effects on dendritic cells (DC) are relatively unknown. DC can really capture Ag from dead and dying cells for presentation to MHC class I-restricted CTL. The main targets for the immunosuppressive calcinerin inhibitors, FK506 and CsA. have been considered to be activated T cells, but not antigen presenting cells (APCs). (omitted)

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Effects of Bifidobacterium spp. isolated from the feces of healthy adults on the enhancement of the presentation of exogenous particulate antigen in association of MHC Class I

  • Han, Shin-Ha;Yun, Yun-Ha;Song, Young-Cheon;Park, Eun-Jung;Choi, Sung-Sook;Ha, Nam-Joo;Kim, Kyung-Jae
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.205.1-205.1
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    • 2003
  • Bifidobacterium spp. is nonpathogenic. Gram-positive and anaerobic bacteria, which inhabit the intestinal tract of humans and animals. Bifidobacterium spp. plays important roles in human health. However. the influence of exogenous factors on species composition of fecal bifidobacteria is still unclear. In this study, we wished to determine whether presentation of exogenous OVA (10 $\mu\textrm{g}$/$m\ell$) could be enhanced by the culture supernatant of ten Bifidobacterium spp. (omitted)

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The Interaction between HCV-Infected huh7.5 Cells and HCV-Specific T Cells (C형 간염 바이러스 감염 간암 세포주와 T 림프구의 상호작용에 대한 연구)

  • Kang, Hyojeung;Cho, Hyosun
    • Korean Journal of Microbiology
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    • v.50 no.2
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    • pp.169-172
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    • 2014
  • Recently, Hepatitis C virus (HCV) replication system has been established using human hepatoma cells (huh cell) and a variety of HCV clones. In this study, we established an infectious HCV replication system using huh7.5 cells and J6/JFH1 clone (genotype 2a). In addition, we investigated the antigen presentation capability of HCV-infected huh7.5 cells to HCV-specific T cells. Interestingly, HCV-infected huh7.5 cells were not capable of activating HCV-specific T cells. However, huh7.5 cells stimulated by exogenous HCV peptide were able to activate HCV-specific T cells, which was shown to produce TNF-${\alpha}$ and IFN-${\gamma}$. We further examined if HCV infection has an inhibitory effect on the expression of MHC class I molecule of huh7.5 cells. We found that HCV infection did not change the expression level of MHC class I molecule on huh7.5 cells.

Expression of Antigen Presenting Function-Associated Surface Molecules on $Interferon{\gamma}$-Treated Gingival Fibroblasts and Periodontal Ligament Fibroblasts (($Interferon{\gamma}$)로 자극된 치은섬유아세포와 치주인대섬유아세 포에서 항원제시기능과 관련된 세포 표면분자의 발현)

  • Seo, Seok-Ran;Ryu, Sung-HunO;Oh, Gwi-Ok;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.30 no.4
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    • pp.895-913
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    • 2000
  • It is becoming increasingly clear that human gingival fibroblasts(HGF) may play a role in regulating immune responsiveness in inflammatory periodontal lesions. Stimulation of HGF with locally-secreted T cell cytokine $IFN_{\gamma}$ induces human leukocyte antigen class II(HLA II) expression on HGF, which is one of the characteristic feature of professional antigen presenting cells(pAPC). However, $IFN_{\gamma}$-treated HGF and other nonprofessional antigen presenting cells(npAPC) are known to be ineffective or less effective antigen presenter to resting T cells. This study, therefore, was undertaken in an effort to elucidate the differences in expression of cell surface molecules between npAPC in periodontal tissues, such as HGF and periodontal ligament fibroblasts(PDLF), and pAPC such as monocytes/macrophages. Using flow cytometry, the levels of cell surface expression of HLA-D, ICAM-1, LFA-3, and B7-1, which are involved in antigen presentation, were determined in HGF, PDLF and human myelomonocytic cell line THP-1. $IFN_{\gamma}$ clearly induced HLA-D expression on both of fibroblasts and monocytes dose dependently. However, expression level on monocytes were 4 to 5 times higher than that on fibroblasts, and induction rate was faster in monocytes than in fibroblasts. The levels of ICAM-1 expression on fibroblasts and monocytes were enhanced by $IFN_{\gamma}$ in a dose dependent manner. On the other hand, the expression of LFA-3 molecule, which could be detected in fibroblasts and monocytes without cytokine stimulation, was no more enhanced by addition of $IFN_{\gamma}$. B7-1, important costimulatory molecule in T cell activation and proliferation, was not detected on both of fibroblasts and monocytes even when stimulated with $IFN_{\gamma}$, except on monocytes fully differentiated by pretreatment of PMA and treated by $IFN_{\gamma}$. These results suggest that delayed expression of HLA-D and absence of B7-1 on $IFN_{\gamma}$ - treated fibroblasts may at least in part be involved in the ineffectiveness of fibroblasts as primary APC. And it is postulated that although periodontal fibroblasts may not serve as primary APC in normal periodontium, sustained expression of HLA II on ubiquitous fibroblasts in inflammatory lesions may perpetuate immune responses and produce chronic inflammation and tissue injury.

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Crosstalk between Adipocytes and Immune Cells in Adipose Tissue Inflammation and Metabolic Dysregulation in Obesity

  • Huh, Jin Young;Park, Yoon Jeong;Ham, Mira;Kim, Jae Bum
    • 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.

The Expression of Codon Optimised Hepatitis B Core Antigen (HBcAg) of Subgenotype B3 Open Reading Frame in Lactococcus lactis

  • Mustopa, Apon Zaenal;Wijaya, Sri Kartika;Ningrum, Ratih Asmana;Agustiyanti, Dian Fitria;Triratna, Lita;Alfisyahrin, Wida Nurul
    • Microbiology and Biotechnology Letters
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    • v.47 no.3
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    • pp.449-458
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    • 2019
  • Hepatitis B treatments using immune therapy are gaining interest because of the improvements in dendritic cell performance for antigen presentation, which induces an appropriate immune response and raises patient survival rates. This research aims to produce a significant amount of the HBcAg antigen, which can induce an immune response and have a curative effect on HBV infection. In this study, the HBV subgenotype B3 of the HBcAg gene was used, which is dominant in Indonesia. Further, Lactococcus lactis bacteria was used as the host because of its safety and tightly regulated protein expression. The codon usage for the HBcAg gene was optimized to improve protein expression in L. lactis, which is important because a codon is not random between species. The HBcAg gene is attached to a pNZ8148 plasmid and transformed into the L. lactis NZ3900 expression host. The results confirm that a positive protein band (21 kDa) in two fractions of purified HBcAg was recognized by both western blotting and dot blot hybridization, even if the HBcAg optimized codon has higher GC contents than that suggested for L. lactis expression. Overall, this research strengthens the broad use of L. lactis bacteria for any protein expression, including higher protein expression of codon optimized HBcAg gene compared to non-optimized genes. Furthermore, the improvement in the codon optimization of the HBcAg gene significantly increases the total protein expression by 10-20%, and the expression level of the codon optimized HBcAg increases 1.5 to 3.2-times that of the native HBcAg.

The Activation of HCV-specific CD8 T Cells by HCV Peptide Pulsed Huh7.5 Cells (Huh7.5 간암 세포주의 HCV 항원제시에 의한 HCV 특이 T 림프구의 활성에 관한 연구)

  • Cho, Hyo-Sun
    • Korean Journal of Microbiology
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    • v.47 no.4
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    • pp.342-347
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    • 2011
  • T cells play a key role in viral infection. However, in patients with chronic hepatitis C virus (HCV) infection, HCV-specific T cells are dysfunctional and impaired in the liver, which is the primary site for HCV replication. There are multiple potential mechanisms for HCV-specific T cell dysfunction including induction of immune inhibitory pathways (program death-1; PD-1, cytotoxic t lymphocyte associated antigen-4; CTLA-4) and immune tolerance induced specific for the liver. However, the interaction between hepatocytes and HCV-specific CD8 T cells has not clearly established. In this study, we confirmed huh (human hepatoma) 7.5 cells expressing HLA (human leukocyte antigen) A2 presented antigen to activate HCV-specific CD8 T cells in HLA A2-restricted manner and expression of PD-L (program death ligand) 1 on huh7.5 cells reduced HCV-specific CD8 T cell activation, suggesting an immune modulatory activity. Loss of HCV-specific tetramer responses following antigenic stimulation correlated with increased caspase-3 activity. In addition, PD-L1 on huh7.5 cells rescued HCV-specific CD8 T cells from apoptosis. Our results suggest that the interaction between PD-L1 and PD-1 can recover the function of HCV-specific CD8 T cells in the liver, which could be applied in therapy of HCV chronic infection.

Significance of a Highly Specific and Sensitive Enzyme Linked Immunosorbent Assay on Evaluation of Environmental Toxicant-Mediated Allergic Responses

  • Kim, Hyoung-Ah;Yong Heo
    • Toxicological Research
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    • v.17
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    • pp.197-199
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    • 2001
  • Enhancement of antigen-specific IgE is a hallmark of allergic hyperresponsiveness, therefore it is necessary to adopt or develop a highly sensitive and specific assay for determination of allergen-specific IgE levels in vivo. In this presentation, we introduce an ELISA (enzyme linked immunosorbent assay) system developed to measure the levels of chicken egg ovalbumin (OVA)-specific IgE in serum. The ELISA method uses a commercially available purified rat anti-mouse IgE as a capture Ab and biotinylated OVA as a detection reagent. Avidin-peroxidase with its substrate is used for color development resulting in optical density measurement at 405 nm. The ELISA system produces a highly sensitive dose-response relation-ship between optical density levels and the dilution titer of the OVA-IgE standard serum but no cross-reaction with unrelated IgE or IgG. It is believed that the system is an Efficient tool to delineate an adjuvant effect of environmental pollutants on development of asthmatic and atopic responses.

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Roles of Heat Shock Protein gp96 in the ER Quality Control: Redundant or Unique Function?

  • Yang, Yi;Li, Zihai
    • Molecules and Cells
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    • v.20 no.2
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    • pp.173-182
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    • 2005
  • Heat shock protein gp96 is an endoplasmic reticulum chaperone, belonging to the HSP90 family. The function of gp96 as a molecular chaperone was discovered more than 10 years ago, but its importance has been overshadowed by the brilliance of its role in immune responses. It is now clear that gp96 is instrumental in the initiation of both the innate and adaptive immunity. Recently, the roles of gp96 in protein homeostasis, as well as in cell differentiation and development, are beginning to draw more attention due to rapid development in the structural study of HSP90 and some surprising new discoveries from genetic studies of gp96. In this review, we focus on the aspect of gp96 as an ER molecular chaperone in protein maturation, peptide binding and the regulation of its activity.

Acute Respiratory Distress Syndrome With Alveolar Hemorrhage due to Strongyloidiasis Hyperinfection in an Older Patient

  • Kim, Eun Jin
    • Annals of Geriatric Medicine and Research
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    • v.22 no.4
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    • pp.200-203
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    • 2018
  • Strongyloides stercoralis is an intestinal nematode that occurs sporadically in temperate areas like Korea. People who are in the immunosuppressed state, over the age of 65 or under the corticosteroid therapy are at risk for developing Strongyloides hyperinfection syndrome. Acute respiratory distress syndrome (ARDS) with alveolar hemorrhage is a rare presentation of Strongyloides hyperinfection. A 78-year-old man had been irregularly injected corticosteroid on his knees, but did not have any immunosuppressive disease. He was initially diagnosed with ARDS and septic shock. Bronchoalveolar lavage (BAL) fluid was bloody and its cytology revealed helminthic larvae identified as S. stercoralis. Results of Cytomegalovirus polymerase chain reaction (PCR), Pneumocystis jirovecii PCR, and Aspergillus antigen testing of the BAL fluid were positive. The clinical progress quickly deteriorated with multiple organ failure, shock and arrhythmia, so he finally died. This is a rare case of ARDS in an older patient without any known immunosuppressive conditions, with alveolar hemorrhage and S. stercoralis being found via BAL.