• Journal of Microbiology
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• 제38권4호
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• pp.203-208
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• 2000

Cytomegalovirus (CMV), a beta-herpesvirus with worldwide distribution, exhibits host persistence, a distinguishing characteristic of all herpesviruses. This persistence is dependent upon restricted gene expression in infected cells as well as the ability of productively infected cells to escape from normal cell-mediated anti-viral immunosurveillance. Type I (IFN-$\alpha$/$\beta$) and type II (IFN-γ) interferons are major components of the innate defense system against viral infection. They are potent inducers of MHC class I and II antigens and of antigen processing proteins. Additionally, IFNS mediate direct antiviral effects through induction effector molecules that block viral infection and replications such as 2', 5-oligoadenylate synthetase (2, 5-OAS). IFNS function through activation of well-defined signal transduction pathways that involve phosphorylation of constituent proteins and ultimate formation of active transcription factors. Recent studies have shown that a number of diverse viruses, including CMV, EBV, HPV mumps and Ebola, are capable of inhibiting IFN-mediated signal transduction through a variety of mechanisms. As an example, CMV infection inhibits the ability of infected cells Is transcribe HLA class I and II antigens as well as the antiviral effector molecules 2, 5-OAS and MxA I. EMSA studies have shown that IFN-$\alpha$ and IFN-γ are unable to induce complete signal transduction in the presence of CMV infection, phenomena that are associated with specific decreases in JAKl and p48. Viral inhibition of IFN signal transduction represents a new mechanistic paradigm for increased viral survival, a paradigm predicting widespread consequences in the case of signal transduction factors common to multiple cytokine pathways.

• IMMUNE NETWORK
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• 제7권4호
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• pp.197-202
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• 2007

Background: Immunomodulators enhancing MHC-restricted antigen presentation would affect many cellular immune reactions mediated by T cells or T cell products. However, modulation of MHC-restricted antigen presentation has received little attention as a target for therapeutic immunoregulation. Here, we report that lectins isolated from mushroom Fomitella fraxinea enhance MHC-restricted exogenous antigen presentation in professional antigen presenting cells (APCs). Methods: Lectins, termed FFrL, were isolated from the carpophores of Fomitella fraxinea, and its effects on the class I and class II MHC-restricted presentation of exogenous ovalbumin (OVA) were examined in mouse dendritic cells (DCs) and mouse peritoneal macrophages. The effects of FFrL on the expression of total MHC molecules and the phagocytic activity were also examined in mouse DCs. Results: DCs cultured in the presence of FFrL overnight exhibited enhanced capacity in presenting exogenous OVA in association with class I and class II MHC molecules. FFrL increased slightly the total expression levels of both class I (H-$2K^b$) and class II (I-$A^b$) MHC molecules and the phagocytic activity of DCs. Antigen presentation-enhancing activity of FFrL was also observed in macrophages isolated from mouse peritoneum. Conclusion: Lectins isolated from the carpophores of Fomitella fraxinea increase MHC-restricted exogenous antigen presentation by enhancing intracellular processing events of phagocytosed antigens.

• 한국양식학회지
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• 제10권4호
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• pp.425-433
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• 1997

황해산 두족류 6종(참갑오징어, Sepia esculenta ; 쇠갑오징어, Sepiella japonica : 한치꼴뚜기, Loligo chinensis : 살오징어, Todarodes pacificus : 참꼴뚜기, Loligo beka : 낙지, Octopus minor)의 안구단백질을 추출하여 항원-항체 교차반응을 실시하였다. 쇠갑오징어, 살오징어와 낙지의 안구단백질로 항혈청(antiserum)을 제작하였으며 갑오징어목, 살오징어목 및 낙지목에 속하는 두족류 6종의 안구단백질을 항원(antigen)으로 사용하였다. 갑오징어목 속하는 쇠갑오징어 및 참갑오징어에서 항원-항체 반응 양상이 매우 뚜렷하였으며 종간 비교에 기준이 될 수 있고 또한 유의성있는 침강선을 볼 수 있었다. 또한 gel filtration chromatography 방법으로 살오징어의 안구단백질을 분획하여 crystallin을 분리하였으며, 주 분획을 SDS-PAGE 전기영동 방법으로 분자량을 추정해 본 결과 약 20-35 KDa 였다.

• IMMUNE NETWORK
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• 제14권6호
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• pp.328-332
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• 2014

Dexamethasone (Dex) was shown to inhibit the differentiation, maturation, and antigen-presenting function of dendritic cells (DC) when added during DC generation or maturation stages. Here, we examined the direct effects of Dex on MHC-restricted antigen processing. Macrophages were incubated with microencapsulated ovalbumin (OVA) in the presence of different concentrations of Dex for 2 h, and the efficacy of OVA peptide presentation was evaluated using OVA-specific CD8 and CD4 T cells. Dex inhibited both class I- and class II-restricted presentation of OVA to T cells; this inhibitory effect on antigen presentation was much more potent in immature macrophages than in mature macrophages. The presentation of the exogenously added OVA peptide SIINFEKL was not blocked by Dex. In addition, short-term treatment of macrophages with Dex had no discernible effects on the phagocytic activity, total expression levels of MHC molecules or co-stimulatory molecules. These results demonstrate that Dex inhibits intracellular processing events of phagocytosed antigens in macrophages.

• 한국동물위생학회지
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• 제29권3호
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• pp.365-376
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• 2006

To identify immune response of leukocytes in peripheral blood of cattle vaccinated with an attenuated live Akabane virus vaccine, leukocytes were reacted with monoclonal antibodies which are specific to bovine lymphocyte surface antigens and assayed by the flow cytometry. Serum neutralizing (SN) test was used to measure antibody titers after vaccination, SN antibody was appeared to 7 days post-vaccination (PV) and 2-8 antibody titers were observed in 14 days PV. Proportion of $CD8^-$ MHC $class II^+$ expressing cells were rapidly increased at 3 days PV. $CD8^+$ MHC $class II^-$ cells were increased at 7 days PV. $CD4^+CD8^-,\;WC^+CD4^-,\;CD4^+CD8^+,\;WC1^-CD4^+, \;WC1^-CD8^+$, and $CD4^-CD8^+$ cells were highly increased at 3, 3, 7, 7, 14, 14 days PV, respectively.

• IMMUNE NETWORK
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• 제10권3호
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• pp.92-98
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• 2010

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to relieve pain, reduce fever and inhibit inflammation. NSAIDs function mainly through inhibition of cyclooxygenase (COX). Growing evidence suggests that NSAIDs also have immunomodulatory effects on T and B cells. Here we examined the effects of NSAIDs on the antigen presenting function of dendritic cells (DCs). Methods: DCs were cultured in the presence of aspirin or ibuprofen, and then allowed to phagocytose biodegradable microspheres containing ovalbumin (OVA). After washing and fixing, the efficacy of OVA peptide presentation by DCs was evaluated using OVA-specific CD8 and CD4 T cells. Results: Aspirin and ibuprofen at high concentrations inhibited both MHC class I and class II-restricted presentation of OVA in DCs. In addition, the DCs generated in the presence of low concentrations of the drugs exhibit a profoundly suppressed capability to present MHC-restricted antigens. Aspirin and ibuprofen did not inhibit the phagocytic activity of DCs, the expression level of total MHC molecules and co-stimulatory molecules on DCs. Ibuprofen rather increased the expression level of total MHC molecules and co-stimulatory molecules on DCs. Conclusion: These results demonstrate that aspirin and ibuprofen inhibit the intracellular processing event of the phagocytosed antigen, and further suggest that prolonged administration of NSAIDs in high doses may impair the capability of DCs to present antigens in asiociation with MHC molecules.

• 통합자연과학논문집
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• 제17권2호
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• pp.59-65
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• 2024

Dendritic cells play a very important role in the immune response as antigen-presenting cells that are critical for initiating both innate and acquired immunity. They recognize, process and present foreign antigens to other key immune cells to trigger and regulate the immune response. The ability to activate these dendritic cells can be used as a treatment for various immune diseases. Maqui berry has been reported to have anticancer, antibacterial and anti-inflammatory properties. However, its effect on the activity of dendritic cells has not been studied. In this study, we investigated the efficacy of maqui berry extract in modulating dendritic cell activity. Treatment of dendritic cells with maqui berry extract induced the costimulatory molecules CD80, CD86, and MHC class I and II in a concentration-dependent manner. Furthermore, the antigen-presenting capacity of dendritic cells was inhibited, which confirms their ability to present antigens, and the production of Interleukin (IL)-12, which is important for dendritic cell activity, was increased. These results indicated that Maqui berry extract activates dendritic cells maturation by inducing the production of co-stimulatory molecules and IL-12. These results suggest that maqui berry extract may act as an effective adjuvant to enhance dendritic cell-based immune responses.

• Journal of Chest Surgery
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• 제29권11호
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• pp.1173-1181
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• 1996

동종동맥판의 보존기법이 발전하면서 상당한 정도의 생육성이 보존되며, 특히 면역반응의 주된 요인인 내피세포 생육성이 약 50%이상 보존되기 때문에 보존처리된 동종동맥판 내피세포의 면역능력을 평가하는것이 동종동맥판의 임상적변화의 원인을 규명하는데 필요할 것이다. 실험은 200~250gm의 Sprague-Dawley Rat를 사용하였다. Rat로부터 적출한 동맥벽을 현재 임상적으로 사용하고 있는 냉장보존법과 냉동보존법을 사용하여 2주일간 보존하였으며 보존처리전(No treat)과 멸균처리후(sterile),냉장 보존후 1(1day), 2(2day), 7(7day), 14일째(14day), 2주간의 냉동보존후(cryo)에 표본을 채취하여 보존시간에 따른 변화를 관찰하였다. 면역표현에 대한 연구를 위하여 혈관조직으로부터 내피세포를 분리한 뒤 면역조직화학검사(Immunohistochemical study)를 하였다. 혈관내피세포의 항원 표현정도를 정량적으로 분석하기 위하여 anti-MHC class I antibody(MRC OX-18)과 anti-MHC class II antibody(MRC OX-6), anti-ICAM antibody를 사용하였다. 처리된 내피세포를 Flow cytomwtry로 분석하여 항체가 부착된 내피세포의 비율을 알아냄으로써 내피세포의 항원성(antigenic expression)을 조사하였다. 또한 보존처리된 동종동맥판에 의한 생체내에서의 면역반응을 평가하기 위하여 위에서와 같은 방법으로 보존처리전(No treat), 멸균처리 후 2일 보존후(2 day), 7일 보존후(7 day), 14일 보존 후(14 day), 냉동보존(cryo)된 동종동맥판을 Mouse에 이식한 후 일정기간(1, 2, 3, 4, 6, 8주)이 경과된 시점에서 혈중의 CD4$^{+}$, CD8$^{+}$ T cell분포를 측정하였다. 이를 위하여 Mouse의 미정맥에서 채취한 혈액에 monoclonal antibody를 처리한 뒤 flow cytometry를 이용하여 lymphocyte중의 CD4$^{+}$, CD8$^{+}$ T cell 비율을 측정하였다. 내피세포의 MHC Class I 표현정도는 No treat에서 23.95%였고, sterile에서 48.08%로 증가한 뒤 14day 까지 36.02%로, cryo에서도 35.53% 로 증가되어 있었다(p=0.0183). MHC Class II 표현정도는 No treat에서 9.72%, sterile에서 10.13%이였고 14day 에서 10.27%, cryo 에서 13.39% 였다(P=0.1599). ICAM-1 표현정도는 No treat에서 15.02%, sterile에서 19.85%였고, 14day에서 35.33%, cryo에서 34.67% 로 증가하였다(P=0.001). 정상 Mouse에서 CD4$^{+}$, CD8$^{+}$ T-cell분포는 각각 42.13%, 25.57% 였고 CD4$^{+}$/CD8$^{+}$ ratio는 1.64였다. 동종동맥을 이식받은 Mouse의 정맥혈중 CD4$^{+}$ T-cell분포는 No treat군에서 1주에서 8주사이에 49.23% 에서 36.8%사이로 변화를 보이지 않았고(p=0.955), 2 day군에서는 30.36%로 감소하였고(p=0.0001), 7day군에서는 32.8%로 감소하였고(p=0.008), 14 day 군은 26.92%로 감소(p=0.0001), cryo군은 29.56%로 감소하였다(p=0.0018). CD8$^{+}$T-cell은 모든 군에서 1주에서 8주 사이에 42.32%에서 58.92%사이로 증가하였다(p=0.0001~0.0002). CD4$^{+}$/CD8$^{+}$ ratio는 모든 군에서 1주에 1.22 에서 2.28 사이에 있었으나 8주후에는 모든 군에서 0.47에서 0.95 사이로 감소하였다(p=0.0001). 즉, 보존처리된 동종동맥판의 내피세포는 보존처리과정의 초기에는 MHC class I과 II항원효과를 동시에 보이고, 보존기간이 길어지면서 MHC class II항원효과는 변함이 없으나 MHC class I 항원효과는 증가함을 알 수 있다. 또한 CD4$^{+}$ T-cell은 보존처리 기간 중 소폭의 변환를 보임에 반하여 CD8$^{+}$ T-cell은 보존처리된 기간에 관계없이 이식된 후 8주간에 걸쳐 지속적으로 증가함을 알 수 있다. 4$^{\circ}C$에 냉장보존한 군과 냉동보존한 군간에는 차이가 없었다. 이와같은 결과를 볼 때 동종동맥판을 체내에 이식할 경우 내피세포에 의한 MHC class I 항원효과가 지속적으로 유지되고 있음을 추측할 수 있다.

• 한국임상약학회지
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• 제29권4호
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• pp.223-230
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• 2019

Background: Small-molecule tyrosine kinase inhibitors (TKIs) have had major impacts on anticancer therapy by targeting the catalytic activities of dysregulated tyrosine kinases. TKIs have not presented traditional toxicities; however, some serious adverse effects, including hepatotoxicity, have been documented in clinical trials and post-marketing surveillance. Although TKI-induced hepatotoxicity can cause severe clinical complications in patients, the underlying mechanism is still unclear. Methods: Studies on TKI-induced hepatotoxicity were identified by Pubmed search, and relevant articles were reviewed. Results: Immunoallergic reaction, cytochrome P (CYP) 450 polymorphisms, and formation of reactive metabolites are under consideration as mechanisms of TKI-induced hepatotoxicity. Host protein-drug metabolite conjugates are recognized as antigens by class II major histocompatibility complexes and are believed to cause liver injuries. Polymorphisms in CYP, which influences TKI metabolism, can slow TKI metabolism and may induce development of hepatotoxicity. The formation of reactive metabolites during drug metabolism can induce hepatotoxicity by directly causing cytotoxicity, leading to cell dysfunction, and indirect toxicity by mediating secondary immune reactions. Concurrent use of various medications with TKI can also cause hepatotoxicity by affecting drug transporter or enzyme activities. Conclusion: Periodic monitoring of patients taking TKIs and risk/benefit reassessments though post marketing surveillance are necessary to prevent hepatotoxicity.

• 한국임상수의학회지
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• 제8권1호
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• pp.1-10
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• 1991

The B-lymphocyte differentiation from committed B-cell progenitors to antibody-secreting cells was discussed. B-cell progenitors derived from hematopoietic stem cells undergo the rearrangement of immunoglobulin(Ig) gene. The earliest cells as B-cell precursors have cytoplasmic Is(${\mu}$ chain). The entire Is molecule is expressed on the surface after synthesis of L chain. The resting B cells(Go stage) stimulated by binding antigen via Ig-receptors are activated(G$_1$ stage) and followed by proliferation(S stage), coupled with further selection(affinity maturation. class switch). The production of antibody against a particular antigen depends on the activation of B cells with surface Is capable of reacting with that antigen. This process does not occur in isolation but is controlled by helper and suppressor T cells and antigen presenting cells(APC). The mechanism of T cell-dependent B-cell response for production of antibody is largely explained by the cell to cell cooperation and soluble helper factors of T cells. 1) The antigen specific B cells and helper T cells are linked by Is-receptors, leading to the delivery of helper signals to the B cells. 2) Helper T cells recognize the processed antigen-derived peptides with the MHC class II molecules(la antigen) and is stimulated to secrete B-cell proliferation and differentiation factors which activate B cells of different antigenic specificity. The two models are shown currently 1) At low antigen concentration, only the antigen-specific B cell binds antigen and presents antigen-derived peptides with la molecules to helper T cells, which are stimulated to secrete cytokines(IL-4, IL-5, etc.) and 2) At high antigen concentration, antigen-derived peptides are presented by specific B cells, by B cells that endocytose the antigens, as well as by APC Cytokines secreted from helper T cells also lead to the activation of B cells and even bystander B cells in the on- vironmment and differentiate them into antibody-secreting plasma cells.