• IMMUNE NETWORK
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• v.22 no.1
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• pp.6.1-6.19
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• 2022

Chimeric antigen receptor (CAR) T cells, which express a synthetic receptor engineered to target specific antigens, have demonstrated remarkable potential to treat haematological malignancies. However, their transition beyond haematological malignancy has so far been unsatisfactory. Here, we discuss recent challenges and improvements for CAR T cell therapy against solid tumors: Antigen heterogeneity which provides an effective escape mechanism against conventional mono-antigen-specific CAR T cells; and the immunosuppressive tumor microenvironment which provides physical and molecular barriers that respectively prevent T cell infiltration and drive T cell dysfunction and hypoproliferation. Further, we discuss the application of CAR T cells in infectious disease and autoimmunity.

• IMMUNE NETWORK
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• v.16 no.2
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• pp.134-139
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• 2016

Programmed death-1 (PD-1) is a strong negative regulator of T lymphocytes in tumor-microenvironment. By engaging PD-1 ligand (PD-L1) on tumor cells, PD-1 on T cell surface inhibits anti-tumor reactivity of tumor-infiltrating T cells. Systemic blockade of PD-1 function using blocking antibodies has shown significant therapeutic efficacy in clinical trials. However, approximately 10 to 15% of treated patients exhibited serious autoimmune responses due to the activation of self-reactive lymphocytes. To achieve selective activation of tumor-specific T cells, we generated T cells expressing a dominant-negative deletion mutant of PD-1 (PD-1 decoy) via retroviral transduction. PD-1 decoy increased IFN-γ secretion of antigen-specific T cells in response to tumor cells expressing the cognate antigen. Adoptive transfer of PD-1 decoy-expressing T cells into tumor-bearing mice potentiated T cell-mediated tumor regression. Thus, T cell-specific blockade of PD-1 could be a useful strategy for enhancing both efficacy and safety of anti-tumor T cell therapy.

• International Journal of Oral Biology
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• v.49 no.2
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• pp.34-41
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• 2024

Extracellular traps (ETs), primarily composed of DNA and antibacterial peptides, are mainly secreted by neutrophils to inhibit pathogen spread and eliminate microorganisms. Recent reports suggest that microglia can also secrete ETs, and these microglial ETs are associated with various neurological conditions, including nerve injury, tumor microenvironment, and ischemic stroke. However, the components and functions of microglial ETs remain underexplored. Secretagogin (Scgn), a calcium-sensor protein, plays a crucial role in the release of peptide hormones, such as insulin, in endocrine cells; however, its function in immune cells, including microglia, is not well understood. Our study demonstrated that Scgn deficiency can lead to the formation of abnormal ETs. We hypothesized that this may involve the c-Jun N-terminal kinase-myeloperoxidase pathway and autophagy.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.2
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• pp.113-119
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• 2019

During tumor progression various immunosuppressive cells are recruited to a tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are particularly abundant in TME. Based on their function, macrophages are categorized into two phenotypes: tumoricidal M1 and tumor-supportive M2. Generally, TAMs closely resemble M2-macrophages and lead to tumor growth. However, their phenotype can be changed by immune activator from M2 to M1 and thus promote tumor immunotherapy. Ginseng extracts are well known for its anti-tumor and anti-inflammatory effects from numerous reported studies. However, the mechanism of their effects is still not clear. Recently, some studies suggested that ginseng extracts induced immune activation as well as anti-tumor activities by a repolarization of activated macrophage from M2 phenotype to M1 phenotype. But, further verification about the mechanism as to how ginseng extracts can stimulate the immune response is still needed. In this study, we investigated whether ginseng extracts can alter the phenotype from M2 macrophages to M1 macrophages in mice by using a radiolabeled liposome. And we also evaluated the potential of radiolabeled liposome as a nuclear imaging agent to monitor the transition of phenotype of TAMs. In conclusion, the ginseng extracts seem to change the phenotype of macrophages from M2 to M1 like as lipopolysaccharide (LPS) in mice.

• Journal of Genetic Medicine
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• v.20 no.2
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• pp.52-59
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• 2023

Purpose: Colorectal cancer (CRC) is a common malignancy worldwide and the second leading cause of cancer-related deaths. In addition, lymph node metastasis in CRC is considered an important prognostic factor for predicting disease recurrence and patient survival. Recent studies demonstrated that the microbiome makes substantial contributions to tumor progression, however, there is still unknown about the microbiome associated with lymph node metastasis of CRC. Here, we first reported the microbial and tumor-infiltrating immune cell differences in CRC according to the lymph node metastasis status. Materials and Methods: Using Next Generation Sequencing data acquired from 368 individuals diagnosed with CRC (N0, 266; N1, 102), we applied the LEfSe to elucidate microbial differences. Subsequent utilization of the Kaplan-Meier survival analysis enabled the identification of particular genera exerting significant influence on patient survival outcomes. Results: We found 18 genera in the N1 group and 3 genera in the N0 group according to CRC lymph node metastasis stages. In addition, we found that the genera Crenobacter (P=0.046), Maricaulis (P=0.093), and Arsenicicoccus (P=0.035) in the N0 group and Cecembia (P=0.08) and Asanoa (P=0.088) in the N1 group were significantly associated with patient survival according to CRC lymph node metastasis stages. Further, Cecembia is highly correlated to tumor-infiltrating immune cells in lymph node metastasized CRC. Concolusion: Our study highlights that tumor-infiltrating immune cells and intratumoral microbe diversity are associated with CRC. Also, this potential microbiome-based oncology diagnostic tool warrants further exploration.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5909-5913
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• 2012

Aims: We aimed to analyze the phenotype of tumor-infiltrating lymphocytes (TILs) and non-tumor infiltrating lymphocytes (NILs) in HCC and non-tumor tissues, and evaluate relationships between changes in these cells and the prognosis of HCC. Methods: Lymphocytes were isolated from HCC and corresponding non-tumor tissues and tested by flow cytometry. For comparison, clinical parameters were analyzed. Results: Compared with the non-tumor tissue, tumor tissue had a lower intensity of NK, NKT andCD8+T cell infiltration. TILs had higher intensity of CD4+CD25+Foxp3+regulatory T cell (Treg cells) infiltration compared with that in NILs. The prevalence of Treg cells was associated with fewer CD8 + T lymphocytes in the HCC immune microenvironment. The frequencies of NK cells and CD8+T cells in TILs of HCC patients with metastasis less than 12 months were lower than those without metastasis. However, the frequency of Treg cells was higher than those without metastasis. Conclusion: These results suggest that the frequencies of CD8+T, NK and NKT cells as well as Treg cells in the tumor tissue of HCC are significantly associated with patient survival, and could be applied as predictive indicators for HCC prognosis.

• IMMUNE NETWORK
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• v.14 no.6
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• pp.296-306
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• 2014

There is growing evidence that crosstalk between mantle cell lymphoma (MCL) cells and stromal microenvironments, such as bone marrow and secondary lymphoid tissues, promotes tumor progression by enhancing survival and growth as well as drug resistance of MCL cells. Recent advances in the understanding of lymphoma microenvironment have led to the identification of crucial factors involved in the crosstalk and subsequent generation of their targeted agents. In the present study, we evaluated the combinatory effect of blocking antibodies (Ab) targeting CXCR4 and VLA-4, both of which were known to play significant roles in the induction of environment-mediated drug resistance (EMDR) in MCL cell line, Jeko-1. Simultaneous treatment with anti-CXCR4 and anti-VLA-4 Ab not only reduced the migration of Jeko-1 cells into the protective stromal cells, but also enhanced sensitivity of Jeko-1 to a chemotherapeutic agent to a greater degree than with either Ab alone. These combinatorial effects were associated with decreased phosphorylation of ERK1/2, AKT and NF-${\kappa}B$. Importantly, drug resistance could not be overcome once the adhesion of Jeko-1 to the stromal occurred despite the combined use of Abs, suggesting that the efforts to mitigate migration of MCLs should be attempted as much as possible. Our results provide a basis for a future development of therapeutic strategies targeting both CXCR4 and VLA-4, such as Ab combinations or bispecific antibodies, to improve treatment outcomes of MCL with grave prognosis.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.463-468
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• 2012

Type 1 diabetes (T1D) is caused by dysregulation of the immune system in the pancreatic islets, which eventually leads to insulin-producing pancreatic ${\beta}$-cell death and destabilization of glucose homeostasis. One of the major characteristics of T1D pathogenesis is the production of inflammatory mediators by macrophages that result in destruction or damage of pancreatic ${\beta}$-cells. In this study the inflammatory microenvironment of T1D was simulated with RAW264.7 cells and MIN6 cells, acting as macrophages and pancreatic ${\beta}$-cells respectably. In this setting, peroxiredoxin-1, an anti-oxidant enzyme was knocked down to observe its functions in the pathogenesis of T1D. RAW264.7 cells were primed with lipopolysaccharide and co-cultured with MIN6 cells while PRX-1 was knocked down in one or both cell types. Our results suggest that hindrance of PRX-1 activity or the deficiency of this enzyme in inflammatory conditions negatively affects pancreatic ${\beta}$-cell survival. The observed decrease in viability of MIN6 cells seems to be caused by nitric oxide production. Additionally, it seems that PRX-1 affects previously reported protective activity of IL-6 in pancreatic ${\beta}$ cells as well. These results signify new, undiscovered roles for PRX-1 in inflammatory conditions and may contribute toward our understanding of autoimmunity.

• Molecules and Cells
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• v.43 no.9
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• pp.763-773
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• 2020

Recently, tumor microenvironment (TME) and its stromal constituents have provided profound insights into understanding alterations in tumor behavior. After each identification regarding the unique roles of TME compartments, non-malignant stromal cells are found to provide a sufficient tumorigenic niche for cancer cells. Of these TME constituents, adipocytes represent a dynamic population mediating endocrine effects to facilitate the crosstalk between cancer cells and distant organs, as well as the interplay with nearby tumor cells. To date, the prevalence of obesity has emphasized the significance of metabolic homeostasis along with adipose tissue (AT) inflammation, cancer incidence, and multiple pathological disorders. In this review, we summarized distinct characteristics of hypertrophic adipocytes and cancer to highlight the importance of an individual's metabolic health during cancer therapy. As AT undergoes inflammatory alterations inducing tissue remodeling, immune cell infiltration, and vascularization, these features directly influence the TME by favoring tumor progression. A comparison between inflammatory AT and progressing cancer could potentially provide crucial insights into delineating the complex communication network between uncontrolled hyperplastic tumors and their microenvironmental components. In turn, the comparison will unravel the underlying properties of dynamic tumor behavior, advocating possible therapeutic targets within TME constituents.

• Biomolecules & Therapeutics
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• v.27 no.1
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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.