• 제목/요약/키워드: peptide-MHC complex

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

  • 강효정;조효선
    • 미생물학회지
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    • 제50권2호
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    • pp.169-172
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    • 2014
  • 최근 인간 간암세포주(human hepatoma cells)를 이용하여 C형 간염 바이러스(hepatitis C virus, HCV)의 복제가 가능한 세포배양모델(cell culture system)이 확립되었다. 본 연구에서는 인간 간암세포주 중 huh7.5 cell (human hepatoma 7.5 cells)과 C형 간염 바이러스인 J6/JFH1 clone (2a 유전자형)를 이용하여 감염 가능한 세포배양모델을 확립하였다. 또한, HCV 감염 간암세포주의 HCV 특이 T 림프구에 대한 항원제시(antigen presentation) 가능성을 살펴보았다. 외부에서 전달된 HCV 항원일 경우 간암세포주의 HCV 특이 T 림프구에 대한 항원제시로 T 림프구의 활성이 가능하였으나, HCV 감염 간암세포주의 경우 T 림프구의 활성을 억제하였다. 이러한 HCV 특이 T 림프구의 활성억제와 HCV 감염 간암세포주 항원제시능의 상관성을 알아보기 위해 HCV 감염 간암세포주의 주조직적합성복합체(major histocompatibility complex, MHC) 발현변화를 측정하였으나 HCV 감염은 간암세포주의 MHC 발현변화에 영향을 미치지 않았다.

Relationship between Condition Index Values and Expression Levels of Gene and Protein in the Adductor Muscle of Diploid and Triploid Oysters Crassostrea gigas

  • Su-Jin Park;Youn Hee Choi
    • 한국발생생물학회지:발생과생식
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    • 제26권4호
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    • pp.165-174
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    • 2022
  • Three proteins [myosin heavy chain (MHC), filamin-C fragment (FIL-C), and actin 2 (ACT2)] were identified in adductor muscle from diploid and triploid Pacific oysters (Crassostrea gigas) and the relationship between the condition index (CI) and mRNA expression of these genes was investigated, together with the mRNA expression of molluscan insulin-related peptide (MIP), C. gigas insulin receptor-related receptor (CIR), and insulin-like growth factor binding protein complex acid labile subunit (IGFBP-ALS). Monthly changes in the CI were similar to the changes in the tissue weight rate in both groups. ACT2 and MHC mRNA expression was statistically higher in the triploid than the diploid, while FIL-C mRNA expression was significantly higher in the diploid (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression of the diploid oysters were all significantly higher in July than in other months (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression in the triploid oysters was high in July, but there were no significant differences (p>0.05). Changes in the expression levels of the genes investigated in this study could be used as intrinsic indicators of the annual growth, maturity, and spawning period of cultured diploid and triploid C. gigas in Tongyeong, Korea.

Immunoinformatics studies and design of a novel multi-epitope peptide vaccine against Toxoplasma gondii based on calcium-dependent protein kinases antigens through an in-silico analysis

  • Ali Dalir Ghaffari;Fardin Rahimi
    • Clinical and Experimental Vaccine Research
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    • 제13권2호
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    • pp.146-154
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    • 2024
  • Purpose: Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5. Materials and Methods: Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted. Results: The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite. Conclusion: In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.

Effects of Mizoribine on MHC-Restricted Exogenous Antigen Presentation in Dendritic Cells

  • Song, Young-Cheon;Han, Shin-Ha;Kim, Hyun-Yul;Kim, Kwang-Hee;Kwon, Jeung-Hak;Lee, Sang-Jin;Ha, Nam-Joo;Lee, Young-Hee;Lee, Chong-Kil;Kim, Kyung-Jae
    • Archives of Pharmacal Research
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    • 제29권12호
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    • pp.1147-1153
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    • 2006
  • Mizoribine (MZR) has been shown to possess immunosuppressive activity that selectively inhibits the proliferation of lymphocytes by interfering with inosine monophosphate dehydrogenase. The efficacy of MZR is not only in patients who have had renal transplantation, but also in patients with rheumatoid arthritis (RA), lupus nephritis, and primary nephritic syndrome. Because the exact mechanism of its immunosuppressive action is not clear, the object of this study was to examine the ability of MZR to regulate the antigen presenting cells (APCs), dendritic cells (DCs). In this work, we tested whether MZR ($1{\sim}10\;{\mu}g/mL$) could inhibit the cross-presentation of DCs. DC2.4 cells ($H-2K^{b}$) or bone marrow-derived DCs (BM-DCs) generated from BM cells of C57BL/6 mouse ($H-2K^{b}$) were cultured in the presence of MZR with OVA-microspheres, and the amount of OVA peptide-class I MHC complexes was measured by a T cell hybridoma, B3Z, that recognizes OVA (257-264 : SIINFEKL)-$H-2K^{b}$ complex and expresses-galactosidase. MZR profoundly inhibited the expression of SIINFEKL-$H-2K^{b}$ complexes. This inhibitory activity of MZR appeared to affect the phagocytic activity of DCs. MZR also decreased IL-2 production when we examined the effects of MZR on $CD4^{+}$ T cells. These results provide an understanding of the mechanism of immunosuppressive activity of MZR on the inhibition of MHC-restricted antigen presentation and phagocytic activity in relation to their actions on APCs.

Generation of Tolerogenic Dendritic Cells and Their Therapeutic Applications

  • Seungbo Yoo;Sang-Jun Ha
    • IMMUNE NETWORK
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    • 제16권1호
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    • pp.52-60
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    • 2016
  • Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that bridge innate and adaptive immune responses, thereby leading to immune activation. DCs have been known to recognize pathogen-associated molecular patterns such as lipopolysaccharides (LPS) and nucleic acids via their pattern recognition receptors, which trigger signaling of their maturation and effector functions. Furthermore, DCs take up and process antigens as a form of peptide loaded on the major histocompatibility complex (MHC) and present them to T cells, which are responsible for the adaptive immune response. Conversely, DCs can also play a role in inducing immune suppression under specific circumstances. From this perspective, the role of DCs is related to tolerance rather than immunity. Immunologists refer to these special DCs as tolerogenic DCs (tolDCs). However, the definition of tolDCs is controversial, and there is limited information on their development and characteristics. In this review, we discuss the current concept of tolDCs, cutting-edge methods for generating tolDCs in vitro, and future applications of tolDCs, including clinical use.

Analysis of the Stability of HLA-A2 Molecules Expressed on the Cell Surface

  • Lim, Jong-Seok;Lee, Ki-Young;Lee, Hee-Gu;Kim, Ik-Hwan;Lee, Chong-Kil;Han, Seong-Sun;Kim, Kil-Hyoun
    • BMB Reports
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    • 제29권4호
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    • pp.286-293
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    • 1996
  • Association of antigenic peptide with class I MHC is believed to be crucial for maintaining stable conformation of class I molecules. T2 cells that are defective in TAP gene function mainly express class I molecules with an unstable conformation due to little or no association with antigenic peptides, whereas T1 cells that are normal in TAP gene function mainly express the stable form of class I molecules. In this work, attempts were made to determine the molecular stability of stable and unstable class I molecules. Dissociation of HLA-A2 molecules on T1 and T2 cells was monitored by flow cytometry using anti-HLA-A2 antibody after the cells were treated with brefeldin A to shut down the transport of newly-assembled HLA-A2. Estimated dissociation rate constants for the stable and unstable forms of HLA-A2 were 0.076 $h^{-1}$ and 0.66 $h^{-1}$, respectively. It appeared that both T1 and T2 cells express stable and unstable class I complex, but with different ratios of the two forms. Furthermore, $interferon-{\gamma}$ treatment of T1 cells appeared to induce the expression of both the stable and unstable class I molecules. These results demonstrate that class I MHC molecules can be divided into two groups in terms of structural stability and that they exist on the cell surface in both forms in a certain ratio.

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