• 제목/요약/키워드: Antigen-presenting cell

검색결과 124건 처리시간 0.021초

수지상세포의 CD1b 분자와 포식작용의 증가 (CD1b in immature dendritic cells acquires increased phagocytotic function)

  • 류현정
    • 미생물학회지
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    • 제54권3호
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    • pp.222-227
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    • 2018
  • CD1 분자는 결핵균 유래 지질항원 발현하는 단백질이며, 특히 수지상세포(dendritic cells)가 결핵균 감염시에 발현이 점차 감소함을 관찰하였다. 이는 결핵균의 사균이나 항원만으로는 관찰되지 않는 결과였다. 2차원 전기영동(2D electrophoresis)을 통하여 CD1b 의 인산화를 관찰하였고 이러한 현상이 식세포작용과 연관됨을 확인하였다.

Emerging Co-signaling Networks in T Cell Immune Regulation

  • Jung, Keunok;Choi, Inhak
    • IMMUNE NETWORK
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    • 제13권5호
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    • pp.184-193
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    • 2013
  • Co-signaling molecules are surface glycoproteins that positively or negatively regulate the T cell response to antigen. Co-signaling ligands and receptors crosstalk between the surfaces of antigen-presenting cells (APCs) and T cells, and modulate the ultimate magnitude and quality of T cell receptor (TCR) signaling. In the past 10 years, the field of co-signaling research has been advanced by the understanding of underlying mechanisms of the immune modulation led by newly identified co-signaling molecules and the successful preclinical and clinical trials targeting co-inhibitory molecules called immune checkpoints in the treatment of autoimmune diseases and cancers. In this review, we briefly describe the characteristics of well-known B7 co-signaling family members regarding the expression, functions and therapeutic implications and to introduce newly identified B7 members such as B7-H5, B7-H6, and B7-H7.

TAGLN2-mediated actin stabilization at the immunological synapse: implication for cytotoxic T cell control of target cells

  • Na, Bo-Ra;Jun, Chang-Duk
    • BMB Reports
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    • 제48권7호
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    • pp.369-370
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    • 2015
  • Actin dynamics is critical for the formation and sustainment of the immunological synapse (IS) during T cell interaction with antigen-presenting cells (APC). Thus, many actin regulating proteins are involved in spatial and temporal actin remodeling at the IS. However, little is known whether or how actin stabilizing protein controls IS and the consequent T cell functions. TAGLN2 − an actin-binding protein predominantly expressed in T cells − displays a novel function to stabilize cortical F-actin, thereby augmenting F-actin contents at the IS, and acquiring leukocyte function-associated antigen-1 activation following T cell activation. TAGLN2 also competes with cofilin to protect F-actin in vitro and in vivo. During cytotoxic T cell interaction with cancer cells, the expression level of TAGLN2 at the IS correlates with the T cell adhesion to target cancer cells and production of lytic granules such as granzyme B and perforin, thus expressing cytotoxic T cell function. These findings identify a novel function for TAGLN2 as an actin stabilizing protein that is essential for stable immunological synapse formation, thereby regulating T cell immunity. [BMB Reports 2015; 48(7): 369-370]

피부면역계 랑게르한스세포의 TNF-$\alpha$생산에 대한 Pedunculagin의 효과 (Effect of Pedunculagin in production of TNF-$\alpha$ of Langerhans Cells)

  • 주성수;오원식;박정환;이도익
    • 약학회지
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    • 제46권6호
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    • pp.477-481
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    • 2002
  • Ellagitannins have been reported to enhance the immune system. In this study, the effects of pedunculagin on langerhans cells were examined. Pedunculagin, an ellagitannin from Alnus hirsuta var. microphylla. Betulaceae, is a novel immunomodulator. Langerhans cell are known as the potent antigen presenting cell and elicit the Contact Hypersensitivity (CHS) response by presenting Ag to trafficking Ag-specific T cells within the skin. For determining the effects af pedunculagin on murine langerhans cell, the expression of TNF-$\alpha$ mRNA was examined by RT-PCR. As a result, the expression of TNF-$\alpha$ mRNA was upregulated by pedunculagin. These results suggest that pedunculagin enhances TNF-$\alpha$ and could be used as an immunomodulator in skin immune system.

Inhibition of Major Histocompatibility Complex (MHC)-Restricted Presentation of Exogenous Antigen in Dendritic Cells by Korean Propolis Components

  • Han, Shin-Ha;Cho, Kyung-Hae;Lee, Seung-Jeong;Lee, Chong-Kil;Song, Young-Cheon;Ha, Nam-Joo;Kim, Kyung-Jae
    • IMMUNE NETWORK
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    • 제5권3호
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    • pp.150-156
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    • 2005
  • Background: Dendritic cells (DCs) playa critical role not only in the initiation of immune responses, but also in the induction of immune tolerance. In an effort to regulate immune responses through the modulation of antigen presenting cell (APC) function of DCs, we searched for and characterized APC function modulators from natural products. Methods: DCs were cultured in the presence of propolis components, WP and CP, and then examined for their ability to present exogenous antigen in association with major histocompatibility complexes (MHC). Results: WP and CP inhibited class I MHC-restricted presentation of exogenous antigen (cross-presentation) in a DC cell line, DC2.4 cells, and DCs generated from bone marrow cells with GM-CSF and IL-4. The inhibitory activity of WP and CP appeared to be due not only to inhibition of phagocytic activity of DCs, but also to suppression of expression of MHC molecules on DCs. We also examined the effects of WP and CP on T cells. Interestingly, WP and CP increased IL-2 production from T cells. Conclusion: These results demonstrate that WP and CP inhibit MHC-restricted presentation of exogenous antigen through down-regulation of phagocytic activity and suppression of expression of MHC molecules on DCs.

Tumor Cell Clone Expressing the Membrane-bound Form of IL-12p35 Subunit Stimulates Antitumor Immune Responses Dominated by $CD8^+$ T Cells

  • Lim, Hoyong;Do, Seon Ah;Park, Sang Min;Kim, Young Sang
    • IMMUNE NETWORK
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    • 제13권2호
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    • pp.63-69
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    • 2013
  • IL-12 is a secretory heterodimeric cytokine composed of p35 and p40 subunits. IL-12 p35 and p40 subunits are sometimes produced as monomers or homodimers. IL-12 is also produced as a membrane-bound form in some cases. In this study, we hypothesized that the membrane-bound form of IL-12 subunits may function as a costimulatory signal for selective activation of TAA-specific CTL through direct priming without involving antigen presenting cells and helper T cells. MethA fibrosarcoma cells were transfected with expression vectors of membrane-bound form of IL-12p35 (mbIL-12p35) or IL-12p40 subunit (mbIL-12p40) and were selected under G418-containing medium. The tumor cell clones were analyzed for the expression of mbIL-12p35 or p40 subunit and for their stimulatory effects on macrophages. The responsible T-cell subpopulation for antitumor activity of mbIL-12p35 expressing tumor clone was also analyzed in T cell subset-depleted mice. Expression of transfected membranebound form of IL-12 subunits was stable during more than 3 months of in vitro culture, and the chimeric molecules were not released into culture supernatants. Neither the mbIL-12p35-expressing tumor clones nor mbIL-12p40-expressing tumor clones activated macrophages to secrete TNF-${\alpha}$. Growth of mbIL-12p35-expressing tumor clones was more accelerated in the $CD8^+$ T cell-depleted mice than in $CD4^+$ T cell-depleted or normal mice. These results suggest that $CD8^+$ T cells could be responsible for the rejection of mbIL-12p35-expressing tumor clone, which may bypass activation of antigen presenting cells and $CD4^+$ helper T cells.

Current Development Status of Cytokines for Cancer Immunotherapy

  • Kyoung Song
    • Biomolecules & Therapeutics
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    • 제32권1호
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    • pp.13-24
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    • 2024
  • Cytokines influence the overall cancer immune cycle by triggering tumor antigen expression, antigen presenting, immune cell priming and activation, effector immune cell recruitment and infiltration to cancer, and cancer killing in the tumor microenvironment (TME). Therefore, cytokines have been considered potential anti-cancer immunotherapy, and cytokine-based anti-cancer therapies continue to be an active area of research and development in the field of cancer immunotherapy, with ongoing clinical trials exploring new strategies to improve efficacy and safety. In this review, we examine past and present clinical developments for major anticancer cytokines, including interleukins (IL-2, IL-15, IL-12, IL-21), interferons, TGF-beta, and GM-CSF. We identify the current status and changes in the technology platform being applied to cytokine-based immune anti-cancer therapeutics. Through this, we discuss the opportunities and challenges of cytokine-based immune anti-cancer treatments in the current immunotherapy market and suggest development directions to enhance the clinical use of cytokines as immuno-anticancer drugs in the future.

Dendritic Cell-based Immunotherapy for Rheumatoid Arthritis: from Bench to Bedside

  • Md. Selim Ahmed;Yong-Soo Bae
    • IMMUNE NETWORK
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    • 제16권1호
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    • pp.44-51
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    • 2016
  • Dendritic cells (DCs) are professional antigen presenting cells, and play an important role in the induction of antigen-specific adaptive immunity. However, some DC populations are involved in immune regulation and immune tolerance. These DC populations are believed to take part in the control of immune exaggeration and immune disorder, and maintain immune homeostasis in the body. Tolerogenic DCs (tolDCs) can be generated in vitro by genetic or pharmacological modification or by controlling the maturation stages of cytokine-derived DCs. These tolDCs have been investigated for the treatment of rheumatoid arthritis (RA) in experimental animal models. In the last decade, several in vitro and in vivo approaches have been translated into clinical trials. As of 2015, three tolDC trials for RA are on the list of ClinicalTrial.gov (www.clinicaltrials.gov). Other trials for RA are in progress and will be listed soon. In this review, we discuss the evolution of tolDC-based immunotherapy for RA and its limitations and future prospects.

피열연골 부위에 발생한 과립세포종 1례 (A Case of Granular Cell Tumor in the Area of Arytenoid Cartilage)

  • 선동일;황성재;김홍래;김민식
    • 대한기관식도과학회지
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    • 제11권1호
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    • pp.28-31
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    • 2005
  • Granular cell tumors are relatively uncommon benign laryngeal lesions thought to originate form Schwann cells. The granular cell tumor occurs everywhere in the body, especially in the head and neck. The larynx is relatively an uncommon location, accounting for approximately 3 to $10\%$ of all reported cases. Typically the most common presenting symptom is hoarseness, with some patients also presenting stridor, hemoptysis, dysphagia, and otlagia. But the tumor may be asymptomatic and discovered only incidentally during a routine examination. The diagnosis of granular cell honor can be confirmed by histopathologically and immunocytochemical staining fer S-100 antigen. Treatment of a granular cell tumor consists of a wide local excision by the endoscopic, transoral or laryngofissure methods. Recently, CO2 laser has been used to remove granular cell tumor with clear resection margin. This article describes one such case in a 62-year-old man, followed by a brief review of the literature on this subject.

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