• 한국임상약학회지
• /
• 제28권1호
• /
• pp.65-75
• /
• 2018

Objective: Over the last several years, immunotherapy has become one of the most promising therapeutic options for cancer. This study aims to summarize the updates on cancer immunotherapy focusing on immune checkpoint inhibitors, such as programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors, which have received attention as new anticancer therapeutic agents. Methods: A literature survey was carried out on PubMed to identify high-impact papers on cancer immunotherapy from 2010. The most recent data on clinical efficacy and safety have been included highlighting the response characteristics to recently approved immunotherapeutic agents. Results: In various cancers, immune checkpoints are a means for cancer cells to evade the immune system. Furthermore, CTLA-4 and PD-L1 can be overexpressed, allowing malignant cells to evade T-cells. Numerous clinical trials have been performed to seek appropriate indication of these products in various cancer types. Among them, the most conspicuous types are melanoma, non-small-cell lung cancer, and head and neck cancer. The approval of ipilimumab by Food and Drug Administration (FDA) commenced a new era of cancer immunotherapy. This was followed by the approval of nivolumab and pembrolizumab. Currently, combination therapies are being investigated for various cancer types. Conclusion: In this study, we reviewed recently reported scientific and clinical evidence for currently approved immune checkpoint inhibitors. Although these novel checkpoint inhibitors are ever evolving for cancer therapies, there exist limitations that need to be overcome, indicating the necessity for further studies aiming to improve their efficacy, toxicity, and cost.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2005년도 2005 Annual Meeting & International Symposium
• /
• pp.115-116
• /
• 2005

• IMMUNE NETWORK
• /
• 제10권4호
• /
• pp.120-125
• /
• 2010

Dysfunction of the virus-specific T cells is a cardinal feature in chronic persistent viral infections such as one caused by hepatitis C virus (HCV). In chronic HCV infection, virus-specific dysfunctional CD8 T cells often overexpress various inhibitory receptors. Programmed cell death 1 (PD-1) was the first among these inhibitory receptors that were identified to be overexpressed in functionally impaired T cells. The roles of other inhibitory receptors such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) have also been demonstrated in T-cell dysfunctions that occur in chronic HCV patients. Blocking these inhibitory receptors in vitro restores the functions of HCV-specific CD8 T cells and allows enhanced proliferation, cytolytic activity and cytokine production. Therefore, the blockade of the inhibitory receptors is considered as a novel strategy for the treatment of chronic HCV infection.

• IMMUNE NETWORK
• /
• 제14권6호
• /
• pp.265-276
• /
• 2014

The interactions between B7 molecules and CD28-family receptors are crucial in the regulation of adaptive cellular immunity. In cancer, the aberrant expression of co-inhibitory B7 molecules has been attributed to reduced anti-tumor immunity and cancer immune evasion, prompting the development of cancer therapeutics that can restore T cell function. Murine tumor models have provided significant support for the targeting of multiple immune checkpoints involving CTLA-4, PD-1, ICOS, B7-H3 and B7-H4 during tumor growth, and clinical studies investigating the therapeutic effects of CTLA-4 and PD-1 blockade have shown exceptionally promising results in patients with advanced melanoma and other cancers. The expression pattern of co-inhibitory B7 ligands in the tumor microenvironment has also been largely correlated with poor patient prognosis, and recent evidence suggests that the presence of several B7 molecules may predict the responsiveness of immunotherapies that rely on pre-existing tumor-associated immune responses. While monotherapies blocking T cell co-inhibition have beneficial effects in reducing tumor burden, combinatorial immunotherapy targeting multiple immune checkpoints involved in various stages of the anti-tumor response has led to the most substantial impact on tumor reduction. In this review, we will examine the contributions of B7- and CD28-family members in the context of cancer development, and discuss the implications of current human findings in cancer immunotherapy.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2005년도 생물공학의 동향(XVII)
• /
• pp.203-204
• /
• 2005

• Experimental and Molecular Medicine
• /
• 제50권12호
• /
• pp.10.1-10.11
• /
• 2018

Cancer growth and progression are associated with immune suppression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. Monoclonal antibodies that target immune checkpoints provided an immense breakthrough in cancer therapeutics. Among the immune checkpoint inhibitors, PD-1/PD-L1 and CTLA-4 inhibitors showed promising therapeutic outcomes, and some have been approved for certain cancer treatments, while others are under clinical trials. Recent reports have shown that patients with various malignancies benefit from immune checkpoint inhibitor treatment. However, mainstream initiation of immune checkpoint therapy to treat cancers is obstructed by the low response rate and immune-related adverse events in some cancer patients. This has given rise to the need for developing sets of biomarkers that predict the response to immune checkpoint blockade and immune-related adverse events. In this review, we discuss different predictive biomarkers for anti-PD-1/PD-L1 and anti-CTLA-4 inhibitors, including immune cells, PD-L1 overexpression, neoantigens, and genetic and epigenetic signatures. Potential approaches for further developing highly reliable predictive biomarkers should facilitate patient selection for and decision-making related to immune checkpoint inhibitor-based therapies.

• IMMUNE NETWORK
• /
• 제20권1호
• /
• pp.11.1-11.14
• /
• 2020

Most patients with hepatocellular carcinoma (HCC) are diagnosed at an advanced stage of disease. Until recently, systemic treatment options that showed survival benefits in HCC have been limited to tyrosine kinase inhibitors, antibodies targeting oncogenic signaling pathways or VEGF receptors. The HCC tumor microenvironment is characterized by a dysfunction of the immune system through multiple mechanisms, including accumulation of various immunosuppressive factors, recruitment of regulatory T cells and myeloid-derived suppressor cells, and induction of T cell exhaustion accompanied with the interaction between immune checkpoint ligands and receptors. Immune checkpoint inhibitors (ICIs) have been interfered this interaction and have altered therapeutic landscape of multiple cancer types including HCC. In this review, we discuss the use of anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies in the treatment of advanced HCC. However, ICIs as a single agent do not benefit a significant portion of patients. Therefore, various clinical trials are exploring possible synergistic effects of combinations of different ICIs (anti-PD-1/PD-L1 and anti-CTLA-4 antibodies) or ICIs and target agents. Combinations of ICIs with locoregional therapies may also improve therapeutic responses.

• 생명과학회지
• /
• 제29권4호
• /
• pp.499-508
• /
• 2019

암줄기세포는 전이와 재발의 주요한 요인이 되는 자가재생능력, 분화할 수 있는 능력, 치료에 대한 저항성 및 암 형성 능력의 특성을 가진다. WNT/${\beta}$-catenin, Hedgehog, Notch, BMI1, BMP 및 TGF-${\beta}$와 같은 암줄기세포의 특성을 획득 및 유지할 수 있는 신호기전의 연구 결과가 존재하지만, 현재까지 선택적으로 암줄기세포를 표적할 수 있는 치료 전략은 미미하다. 최근, 면역관문억제제인 CTLA-4, PD-1/PD-L1 단일클론항체는 흑색종, 폐암, 췌장암 및 혈액암에 괄목할만한 임상 시험 결과를 나타냈으며, 긴 항암지속효과와 적은 부작용은 기존 항암제보다 개선 된 모습을 보였다. 또한 두경부편평상피암, 흑색종, 유방암 줄기세포를 선택적으로 제거 하였다. 위의 결과를 종합하면, 면역관문억제제는 이전 항암제에 비해 효과적인 항암전략이며, 동시에 암줄기세포를 선택적으로 제거할 수 있는 가능성을 시사한다. 따라서 본 리뷰에서는 암줄기세포와 면역관문억제제의 이해를 통해, 면역관문억제제의 암줄기세포 표적 가능성에 대해 고찰하고자 한다.

• Parasites, Hosts and Diseases
• /
• 제54권2호
• /
• pp.163-171
• /
• 2016

As most infections by the helminth parasite elicit the recruitment of $CD4^+CD25^+Foxp3^+$ T ($T_{reg}$) cells, many scientists have suggested that these cells could be used for the treatment of immune-mediated inflammation and associated diseases. In order to investigate the distribution and alteration of activated $T_{reg}$ cells, we compared the expression levels of $T_{reg}$ cell activation markers in the ileum and gastrocnemius tissues 1, 2, and 4 weeks after infection. The number of $T_{reg}$ cells was monitored using GFP-coded Foxp3 transgenic mice. In mice at 1 week after Trichinella spiralis infection, the number of activated $T_{reg}$ cells was higher than in the control group. In mice at 2 weeks after infection, there was a significant increase in the number of cells expressing Foxp3 and CTLA-4 when compared to the control group and mice at 1 week after infection. At 4 weeks after infection, T. spiralis was easily identifiable in nurse cells in mouse muscles. In the intestine, the expression of Gzmb and Klrg1 decreased over time and that of Capg remained unchanged for the first and second week, then decreased in the 4th week. However, in the muscles, the expression of most chemokine genes was increased due to T. spiralis infection, in particular the expression levels of Gzmb, OX40, and CTLA-4 increased until week 4. In addition, increased gene expression of all chemokine receptors in muscle, CXCR3, CCR4, CCR5, CCR9, and CCR10, was observed up until the 4th week. In conclusion, various chemokine receptors showed increased expressions combined with recruitment of $T_{reg}$ cells in the muscle tissue.

• Journal of Ginseng Research
• /
• 제36권4호
• /
• pp.375-382
• /
• 2012

Ginsenoside Rp1 (G-Rp1) is a saponin derivate that provides anti-metastatic activities through inhibition of the NF-${\kappa}B$ pathway. In this study, we examined the effects of G-Rp1 on regulatory T cell (Treg) activation. After treatment of splenocytes with G-Rp1, Tregs exhibited upregulation of IL-10 expression, and along with dendritic cells (DCs), these Tregs showed increased cell number compared to other cell populations. The effect of G-Rp1 on Treg number was augmented in the presence of lipopolysaccharide (LPS), which mimics pathological changes that occur during inflammation. However, depletion of DCs prevented the increase in Treg number in the presence of G-Rp1 and/or LPS. In addition, G-Rp1 promoted the differentiation of the memory types of $CD4^+Foxp3^+CD62L^{low}$ Tregs rather than the generation of new Tregs. In vivo experiments also demonstrated that Tregs and DCs from mice that were fed G-Rp1 for 7 d and then injected with LPS exhibited increased activation compared with those from mice that were injected with LPS alone. Expression of TGF-${\beta}$ and CTLA4 in Tregs was increased, and upregulation of IL-2 and CD80/CD86 expression by DCs affected the suppressive function of Tregs through IL-2 receptors and CTLA4. These data demonstrate that G-Rp1 exerts anti-inflammatory effects by activating Tregs in vitro and in vivo.