• 제목/요약/키워드: checkpoint

검색결과 269건 처리시간 0.023초

Analysis of the Expression and Regulation of PD-1 Protein on the Surface of Myeloid-Derived Suppressor Cells (MDSCs)

  • Nam, Sorim;Lee, Aram;Lim, Jihyun;Lim, Jong-Seok
    • Biomolecules & Therapeutics
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    • 제27권1호
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    • pp.63-70
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    • 2019
  • Myeloid-derived suppressor cells (MDSCs) that are able to suppress T cell function are a heterogeneous cell population frequently observed in cancer, infection, and autoimmune disease. Immune checkpoint molecules, such as programmed death 1 (PD-1) expressed on T cells and its ligand (PD-L1) expressed on tumor cells or antigen-presenting cells, have received extensive attention in the past decade due to the dramatic effects of their inhibitors in patients with various types of cancer. In the present study, we investigated the expression of PD-1 on MDSCs in bone marrow, spleen, and tumor tissue derived from breast tumor-bearing mice. Our studies demonstrate that PD-1 expression is markedly increased in tumor-infiltrating MDSCs compared to expression in bone marrow and spleens and that it can be induced by LPS that is able to mediate $NF-{\kappa}B$ signaling. Moreover, expression of PD-L1 and CD80 on $PD-1^+$ MDSCs was higher than on $PD-1^-$ MDSCs and proliferation of MDSCs in a tumor microenvironment was more strongly induced in $PD-1^+$ MDSCs than in $PD-1^-$ MDSCs. Although we could not characterize the inducer of PD-1 expression derived from cancer cells, our findings indicate that the study on the mechanism of PD-1 induction in MDSCs is important and necessary for the control of MDSC activity; our results suggest that $PD-1^+$ MDSCs in a tumor microenvironment may induce tumor development and relapse through the modulation of their proliferation and suppressive molecules.

Home IoT 가전의 보안위협모델링을 통한 보안요구사항 분석에 관한 연구 (A Study on Security Requirments Analysis through Security Threat Modeling of Home IoT Appliance)

  • 윤석진;김정덕
    • 한국전자거래학회지
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    • 제24권2호
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    • pp.113-124
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    • 2019
  • 최근 많은 기업은 IoT가 적용된 제품들을 개발하여 판매하고 있으며, 외부의 위협으로부터 제품 및 사용자 정보를 보호하기 위해 기획 단계서부터 보안을 고려하고 있다. 그러나 IoT의 다양성으로 인해 제품별 보안요구사항 개발을 하기 위해 투자되는 시간과 인력의 한계가 있어 현재 낮은 수준의 보안이 적용되어 있다. IoT가 적용된 제품에서 취약점이 지속적으로 발표되고 있고, 이에 실제 Home IoT에 대한 보다 상세한 보안요구사항이 필요하게 되었다. 이를 위해 본 논문에서는 Microsoft사의 Threat Modeling Tool을 사용하여 Home IoT의 위협을 도출하였으며, 도출된 위협과 국내 외 취약점 평가 기준 및 논문 등과 비교 분석하여 실제 보안성 점검에 사용할 수 있는 항목을 개발하여 Home IoT 제품의 보안성 강화방안을 제시하였다. 또한 도출된 보안요구사항과 기존의 보안요구사항을 바탕으로 점검을 실시하여 효과성 검토를 하였으며, 그 결과 본 논문에서 도출된 보안요구사항의 취약점 발견 효과성이 대체로 높은 것으로 나타났다.

근거리 사진측량을 위한 스테레오 카메라의 안정성 분석 (Stability Analysis of a Stereo-Camera for Close-range Photogrammetry)

  • 김의명;최인하
    • 한국측량학회지
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    • 제39권3호
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    • pp.123-132
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    • 2021
  • 근거리 사진측량에서 스테레오 카메라를 이용하여 3차원 위치를 결정하기 위해 카메라의 내부표정요소뿐만 아니라 카메라 간의 상호표정요소를 결정하는 카메라 캘리브레이션이 선행되어야 한다. 카메라 캘리브레이션을 수행하고 나서 시간이 흐르면 비측량용 카메라의 경우 내부적인 불안정성이나 외부적인 요인에 의해 내부표정요소와 상호표정요소가 변할 수 있다. 본 연구에서는 스테레오 카메라 안정성을 평가하기 위해 두 대의 단일 카메라와 스테레오 카메라의 안정성을 분석뿐만 아니라 검사점을 이용하여 3차원 위치 정확도를 평가하였다. 4개월간 3회의 카메라 캘리브레이션을 수행한 실험을 통해 단일 카메라의 안정성을 평가한 결과 평균제곱근오차는 ±0.001mm로 나타났으며, 스테레오 카메라의 평균제곱근오차는 ±0.012mm ~ ±0.025mm로 나타났다. 또한, 검사점을 이용한 거리정확도를 평가한 결과 ±1mm로 나타나 다시기에 걸쳐 추정한 스테레오 카메라의 내부표정요소와 상호표정요소는 안정적인 것으로 판단되었다.

Bispecific Antibody-Bound T Cells as a Novel Anticancer Immunotherapy

  • Cho, Jaewon;Tae, Nara;Ahn, Jae-Hee;Chang, Sun-Young;Ko, Hyun-Jeong;Kim, Dae Hee
    • Biomolecules & Therapeutics
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    • 제30권5호
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    • pp.418-426
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    • 2022
  • Chimeric antigen receptor T (CAR-T) cell therapy is one of the promising anticancer treatments. It shows a high overall response rate with complete response to blood cancer. However, there is a limitation to solid tumor treatment. Additionally, this currently approved therapy exhibits side effects such as cytokine release syndrome and neurotoxicity. Alternatively, bispecific antibody is an innovative therapeutic tool that simultaneously engages specific immune cells to disease-related target cells. Since programmed death ligand 1 (PD-L1) is an immune checkpoint molecule highly expressed in some cancer cells, in the current study, we generated αCD3xαPD-L1 bispecific antibody (BiTE) which can engage T cells to PD-L1+ cancer cells. We observed that the BiTE-bound OT-1 T cells effectively killed cancer cells in vitro and in vivo. They substantially increased the recruitment of effector memory CD8+ T cells having CD8+CD44+CD62Llow phenotype in tumor. Interestingly, we also observed that BiTE-bound polyclonal T cells showed highly efficacious tumor killing activity in vivo in comparison with the direct intravenous treatment of bispecific antibody, suggesting that PD-L1-directed migration and engagement of activated T cells might increase cancer cell killing. Additionally, BiTE-bound CAR-T cells which targets human Her-2/neu exhibited enhanced killing effect on Her-2-expressing cancer cells in vivo, suggesting that this could be a novel therapeutic regimen. Collectively, our results suggested that engaging activated T cells with cancer cells using αCD3xαPD-L1 BiTE could be an innovative next generation anticancer therapy which exerts simultaneous inhibitory functions on PD-L1 as well as increasing the infiltration of activated T cells having effector memory phenotype in tumor site.

Sarcoma Immunotherapy: Confronting Present Hurdles and Unveiling Upcoming Opportunities

  • Sehan Jeong;Sharmin Afroz;Donghyun Kang;Jeonghwan Noh;Jooyeon Suh;June Hyuk Kim;Hye Jin You;Hyun Guy Kang;Yi-Jun Kim;Jin-Hong Kim
    • Molecules and Cells
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    • 제46권10호
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    • pp.579-588
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    • 2023
  • Sarcomas are rare and heterogeneous mesenchymal neoplasms originating from the bone or soft tissues, which pose significant treatment challenges. The current standard treatment for sarcomas consists of surgical resection, often combined with chemo- and radiotherapy; however, local recurrence and metastasis remain significant concerns. Although immunotherapy has demonstrated promise in improving long-term survival rates for certain cancers, sarcomas are generally considered to be relatively less immunogenic than other tumors, presenting substantial challenges for effective immunotherapy. In this review, we examine the possible opportunities for sarcoma immunotherapy, noting cancer testis antigens expressed in sarcomas. We then cover the current status of immunotherapies in sarcomas, including progress in cancer vaccines, immune checkpoint inhibitors, and adoptive cellular therapy and their potential in combating these tumors. Furthermore, we discuss the limitations of immunotherapies in sarcomas, including a low tumor mutation burden and immunosuppressive tumor microenvironment, and explore potential strategies to tackle the immunosuppressive barriers in therapeutic interventions, shedding light on the development of effective and personalized treatments for sarcomas. Overall, this review provides a comprehensive overview of the current status and potential of immunotherapies in sarcoma treatment, highlighting the challenges and opportunities for developing effective therapies to improve the outcomes of patients with these rare malignancies.

Evolution of Radiological Treatment Response Assessments for Cancer Immunotherapy: From iRECIST to Radiomics and Artificial Intelligence

  • Nari Kim;Eun Sung Lee;Sang Eun Won;Mihyun Yang;Amy Junghyun Lee;Youngbin Shin;Yousun Ko;Junhee Pyo;Hyo Jung Park;Kyung Won, Kim
    • Korean Journal of Radiology
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    • 제23권11호
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    • pp.1089-1101
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    • 2022
  • Immunotherapy has revolutionized and opened a new paradigm for cancer treatment. In the era of immunotherapy and molecular targeted therapy, precision medicine has gained emphasis, and an early response assessment is a key element of this approach. Treatment response assessment for immunotherapy is challenging for radiologists because of the rapid development of immunotherapeutic agents, from immune checkpoint inhibitors to chimeric antigen receptor-T cells, with which many radiologists may not be familiar, and the atypical responses to therapy, such as pseudoprogression and hyperprogression. Therefore, new response assessment methods such as immune response assessment, functional/molecular imaging biomarkers, and artificial intelligence (including radiomics and machine learning approaches) have been developed and investigated. Radiologists should be aware of recent trends in immunotherapy development and new response assessment methods.

Commensal Microbiota and Cancer Immunotherapy: Harnessing Commensal Bacteria for Cancer Therapy

  • Jihong Bae; Kwangcheon Park;You-Me Kim
    • IMMUNE NETWORK
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    • 제22권1호
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    • pp.3.1-3.21
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    • 2022
  • Cancer is one of the leading causes of death worldwide and the number of cancer patients is expected to continuously increase in the future. Traditional cancer therapies focus on inhibiting cancer growth while largely ignoring the contribution of the immune system in eliminating cancer cells. Recently, better understanding of immunological mechanisms pertaining to cancer progress has led to development of several immunotherapies, which revolutionized cancer treatment. Nonetheless, only a small proportion of cancer patients respond to immunotherapy and maintain a durable response. Among multiple factors contributing to the variability of immunotherapy response rates, commensal microbiota inhabiting patients have been identified as one of the most critical factors determining the success of immunotherapy. The functional diversity of microbiota differentially affects the host immune system and controls the efficacy of immunotherapy in individual cancer patients. Moreover, clinical studies have demonstrated that changing the gut microbiota composition by fecal microbiota transplantation in patients who failed a previous immunotherapy converts them to responders of the same therapy. Consequently, both academic and industrial researchers are putting extensive efforts to identify and develop specific bacteria or bacteria mixtures for cancer immunotherapy. In this review, we will summarize the immunological roles of commensal microbiota in cancer treatment and give specific examples of bacteria that show anticancer effect when administered as a monotherapy or as an adjuvant agent for immunotherapy. We will also list ongoing clinical trials testing the anticancer effect of commensal bacteria.

Immunotherapy for Non-small Cell Lung Cancer: Current Landscape and Future Perspectives

  • Sun Min Lim;Min Hee Hong;Hye Ryun Kim
    • IMMUNE NETWORK
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    • 제20권1호
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    • pp.10.1-10.14
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    • 2020
  • Immune checkpoint inhibitors (ICIs) have shown remarkable benefit in the treatment of patients with non-small-cell lung cancer (NSCLC) and have emerged as an effective treatment option even in the first-line setting. ICIs can block inhibitory pathways that restrain the immune response against cancer, restoring and sustaining antitumor immunity. Currently, there are 4 PD-1/PD-L1 blocking agents available in clinics, and immunotherapy-based regimen alone or in combination with chemotherapy is now preferred option. Combination trials assessing combination of ICIs with chemotherapy, targeted therapy and other immunotherapy are ongoing. Controversies remain regarding the use of ICIs in targetable oncogene-addicted subpopulations, but their initial treatment recommendations remained unchanged, with specific tyrosine kinase inhibitors as the choice. For the majority of patients without targetable driver oncogenes, deciding between therapeutic options can be difficult due to lack of direct cross-comparison studies. There are continuous efforts to find predictive biomarkers to find those who respond better to ICIs. PD-L1 protein expressions by immunohistochemistry and tumor mutational burden have emerged as most well-validated biomarkers in multiple clinical trials. However, there still is a need to improve patient selection, and to establish the most effective concurrent or sequential combination therapies in different NSCLC clinical settings. In this review, we will introduce currently used ICIs in NSCLC and analyze most recent trials, and finally discuss how, when and for whom ICIs can be used to provide promising avenues for lung cancer treatment.

해죽순(Nipa fruticans Wurmb) 추출물의 UVB 유도 DNA 손상 및 MMP 발현 억제 효과 (Effects of Nipa fruticans Wurmb Extract on Inhibition of UVB-Induced DNA Damage and MMP Expression)

  • 한소연;장태원;이다윤;문지선;김용신;박재호
    • 대한화장품학회지
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    • 제50권3호
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    • pp.271-278
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    • 2024
  • 인간의 피부는 물리적 요인, 화학적 요인으로부터 신체를 보호하는 기관이다. 피부는 신체 기관중 가장 크고 거대하며 표피, 진피, 및 피하조직으로 구성된다. 피부에 지속적인 자외선 노출은 DNA 손상, 단백질의 산화, 및 성인병을 유발하는 요인이 될 수 있다. Nypa fruticans Wurmb (NF)에는 풍부한 식물화학물질(폴리페놀 및 플라보노이드)이 포함되어 있기 때문에 전통적으로 호흡기 및 질환을 치료하는데 사용되어져 왔다. 본 연구에서는 UVB로 자극된 Hs68 세포에서 NF 에틸아세테이트 분획물(ENF)의 DNA damage 치유 및 주름 관련 인자억제에 대한 효과를 조사했다. Westernblotting을 통해 DNA damage 관련 단백질 인자 및 주름 관련 단백질 인자의 발현을 확인했다. 또한, wound-healing 실험을 통해 ENF의 상처 회복 능력을 확인했다. ENF는 DNA damage 관련 단백질 인산화된 H2AX (γ-H2AX), checkpoint kinase 2 (Chk2), protein53 (p53), 및 인산화된 protein53 (p-p53)의 발현을 유의하게 억제했다. 뿐만아니라, ENF는 주름 관련 단백질 matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-3 (MMP-3), 및 matrix metalloproteinase-9 (MMP-9)의 발현도 억제했다. 고농도의 ENF 처리 시 Hs68 세포의 상처치유 효과도 확인되었다. 결론적으로, ENF는 γ-H2AX, Chk2, p53, 및 p-p53의 발현을 유의하게 억제해서 DNA damage를 치유하고 MMP-1, MMP-3, 및 MMP-9의 발현을 억제 함으로써 주름 생성억제가능성이 있다고 생각된다. 이러한 결과는 ENF가 UVB로 자극된 Hs68에서 γ-H2AX, Chk2, p53 및 MMP 경로를 조절하여 UVB로 인한 피부의 손상을 억제할 수 있는 천연자원으로 이용될 수 있을 것으로 생각된다.

An engineered PD-1-based and MMP-2/9-oriented fusion protein exerts potent antitumor effects against melanoma

  • Wei, Mulan;Liu, Xujie;Cao, Chunyu;Yang, Jianlin;Lv, Yafeng;Huang, Jiaojiao;Wang, Yanlin;Qin, Ye
    • BMB Reports
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    • 제51권11호
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    • pp.572-577
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    • 2018
  • Recent studies showed that the PD-1/PD-L1 checkpoint blockade is a dramatic therapy for melanoma by enhancing antitumor immune activity. Currently, major strategies for the PD-1/PD-L1 blockade have mainly focused on the use of antibodies and compounds. Seeking an alternative approach, others employ endogenous proteins as blocking agents. The extracellular domain of PD-1 (ePD1) includes the binding site with PD-L1. Accordingly, we constructed a PD-1-based recombinantly tailored fusion protein (dFv-ePD1) that consists of bivalent variable fragments (dFv) of an MMP-2/9-targeted antibody and ePD1. The melanoma-binding intensity and antitumor activity were also investigated. We found the intense and selective binding capability of the protein dFv-ePD1 to human melanoma specimens was confirmed by a tissue microarray. In addition, dFv-ePD1 significantly suppressed the migration and invasion of mouse melanoma B16-F1 cells, and displayed cytotoxicity to cancer cells in vitro. Notably, dFv-ePD1 significantly inhibited the growth of mouse melanoma B16-F1 tumor cells in mice and in vivo fluorescence imaging showed that dFv-ePD was gradually accumulated into the B16-F1 tumor. Also the B16-F1 tumor fluorescence intensity at the tumor site was stronger than that of dFv. This study indicates that the recombinant protein dFv-ePD1 has an intensive melanoma-binding capability and exerts potent therapeutic efficacy against melanoma. The novel format of the PD-L1-blocked agent may play an active role in antitumor immunotherapy.