• IMMUNE NETWORK
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• v.23 no.5
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• pp.36.1-36.16
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• 2023

Thymic epithelial cells (TECs) play a critical role in thymic development and thymopoiesis. As individuals age, TECs undergo various changes that impact their functions, leading to a reduction in cell numbers and impaired thymic selection. These age-related alterations have been observed in both mice and humans. However, the precise mechanisms underlying age-related TEC dysfunction remain unclear. Furthermore, there is a lack of a comprehensive study that connects mouse and human biological processes in this area. To address this gap, we conducted an extensive transcriptome analysis of young and old TECs in mice, complemented by further analysis of publicly available human TEC single-cell RNA sequencing data. Our analysis revealed alterations in both known and unknown pathways that potentially contribute to age-related TEC dysfunction. Specifically, we observed downregulation of pathways related to cell proliferation, T cell development, metabolism, and cytokine signaling in old age TECs. Conversely, TGF-β, BMP, and Wnt signaling pathways were upregulated, which have been known to be associated with age-related TEC dysfunctions or newly discovered in this study. Importantly, we found that these age-related changes in mouse TECs were consistently present in human TECs as well. This cross-species validation further strengthens the significance of our findings. In conclusion, our comprehensive analysis provides valuable insight into the biological and immunological characteristics of aged TECs in both mice and humans. These findings contribute to a better understanding of thymic involution and age-induced immune dysfunction.

• IMMUNE NETWORK
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• v.21 no.3
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• pp.18.1-18.13
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• 2021

TLR signaling is critical for broad scale immune recognition of pathogens and/or danger molecules. TLRs are particularly important for the activation and the maturation of cells comprising the innate immune response. In recent years it has become apparent that several different TLRs regulate the function of lymphocytes as well, albeit to a lesser degree compared to innate immunity. TLR2 heterodimerizes with either TLR1 or TLR6 to broadly recognize bacterial lipopeptides as well as several danger-associated molecular patterns. In general, TLR2 signaling promotes immune cell activation leading to tissue inflammation, which is advantageous for combating an infection. Conversely, inappropriate or dysfunctional TLR2 signaling leading to an overactive inflammatory response could be detrimental during sterile inflammation and autoimmune disease. This review will highlight and discuss recent research advances linking TLR2 engagement to autoimmune inflammation.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3587-3592
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• 2013

Aims: To study the CIK cell treatment effects on regulation of cellular immune function disorders in patients with lung cancer, and to analyze the time characteristics. Methods: Cellular immune function was assessed by FCM, and patients with functional disorders were randomly divided into two groups, one given CIK cell therapy within 18 months (5 courses) and the other the controls, which were followed up for 1 year with cellular immune functions tested once a month. Results: There were 5 types of cellular immunity, 4 of which are disorders; after CIK treatment, the improvement rate of the 4 groups were 79.1%, 70.8%, 76.0% and 70.0%, intergroup differences not being statistically significant (P=0.675), all significantly higher than in the control group (P=0.000). The median maintenance times for the 4 groups were 10.4 months (9.76-11.04), 8.4 months (7.86-8.94), 9.8 months (9.20-10.4) and 7.9 months (6.25-9.55), respectively. Conclusions: CIK cells were able to improve the immune functions of patients with lung cancer, the rate of improvement and maintenance time being related to the immune function before the treatment and CIK-cell-therapy courses.

• BMB Reports
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• v.54 no.1
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• pp.44-58
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• 2021

Natural killer (NK) cells, key antitumor effectors of the innate immune system, are endowed with the unique ability to spontaneously eliminate cells undergoing a neoplastic transformation. Given their broad reactivity against diverse types of cancer and close association with cancer prognosis, NK cells have gained considerable attention as a promising therapeutic target for cancer immunotherapy. NK cell-based therapies have demonstrated favorable clinical efficacies in several hematological malignancies but limited success in solid tumors, thus highlighting the need to develop new therapeutic strategies to restore and optimize anti-tumor activity while preventing tumor immune escape. The current therapeutic modalities yielding encouraging results in clinical trials include the blockade of immune checkpoint receptors to overcome the immune-evasion mechanism used by tumors and the incorporation of tumor-directed chimeric antigen receptors to enhance NK cell anti-tumor specificity and activity. These observations, together with recent advances in the understanding of NK cell activation within the tumor microenvironment, will facilitate the optimal design of NK cell-based therapy against a broad range of cancers and, more desirably, refractory cancers.

• Biomedical Science Letters
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• v.25 no.1
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• pp.66-74
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• 2019

Hyperlipidemia is defined as conditions of the accumulation of lipids such as free fatty acids (FFA), triglyceride (TG), cholesterol and/or phospholipid in the bloodstream. Hyperlipidemia can cause lipid accumulation in non-adipose tissue, which is lipid-cytotoxic effects in many tissues and mediates cell dysfunction, inflammation or programmed cell death (PCD). TG is considered to be a major cause of atherosclerosis through inflammatory necrosis of vascular endothelial cells. Recently, TG have also been shown to exhibit lipid-cytotoxicity and induce PCD. Therefore, we investigated the effect of TG on the cytotoxic effect of various cell types. When exposed to TG, the cell viability of U937 monocytes and Jurkat T lymphocytes, as well as the cell viability of MCF-7, a non-immune cell, decreased in time- and dose-dependent manner. In U937 cells and Jurkat cells, caspase-9, an intrinsic apoptotic caspase, and caspase-8, an extrinsic apoptotic caspase, were increased by exposure to TG. However, in TG-treated MCF-7 cells, caspase-8 activity increased only without caspase-9 activity. In addition, the reduction of cell viability by TG was recovered when all three cell lines were treated with pan-caspase inhibitor. These results suggest that activation of apoptotic caspases by TG causes lipotoxic effect and decreases cell viability.

• Archives of Pharmacal Research
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• v.20 no.3
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• pp.225-233
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• 1997

A murine leukemia x LM fibroblast hybrid cell line with immune augmenting properties stimulated resistance to Mycobacterium avium complex (MAC) in mouse peritoneal macrophages, and in immune deficient beige mice (C57BL/6/bgj/bgj). The proliferation of MAC in mouse peritoneal macrophages was inhibited by medium conditioned by the growth of the hybrid cells (hybrid cell-CM). Under similar circumstances, media conditioned by the growth of LM cells (LM cell-CM), a mouse fibroblast cell line used as one parent in forming the hybrid cell, was exhibited no inhibitory effect. Treatment of mouse peritoneal macrophages with hybrid cell-CM, but not with LM cell-CM, stimulated the expression of each of four previously described macrophage activation antigens, suggesting that the hybrid cells formed immunomodulators in addition to those formed by LM cells. Furthermore, the morphology of the macrophages following treatment with hybrid cell-CM was clearly distinguishable from that following exposure of the cells to LM cell-CM. The therapeutic effects of hybrid cells on the progression of MAC-infection were indicated by the prolonged survival of MAC-infected immune-deficient beige mice. One hundred percent of treated animals survived more than 60 days, while untreated animals died in approximately 22 days.

• Smart Structures and Systems
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• v.8 no.1
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• pp.69-92
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• 2011

This paper presents an emergent pattern recognition approach based on the immune network theory and hierarchical clustering algorithms. The immune network allows its components to change and learn patterns by changing the strength of connections between individual components. The presented immune-network-based approach achieves emergent pattern recognition by dynamically generating an internal image for the input data patterns. The members (feature vectors for each data pattern) of the internal image are produced by an immune network model to form a network of antibody memory cells. To classify antibody memory cells to different data patterns, hierarchical clustering algorithms are used to create an antibody memory cell clustering. In addition, evaluation graphs and L method are used to determine the best number of clusters for the antibody memory cell clustering. The presented immune-network-based emergent pattern recognition (INEPR) algorithm can automatically generate an internal image mapping to the input data patterns without the need of specifying the number of patterns in advance. The INEPR algorithm has been tested using a benchmark civil structure. The test results show that the INEPR algorithm is able to recognize new structural damage patterns.

• IMMUNE NETWORK
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• v.20 no.1
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• pp.9.1-9.21
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• 2020

Immune checkpoint inhibitors (ICIs) have been changing the paradigm of cancer treatment. However, immune-related adverse effects (irAEs) have also increased with the exponential increase in the use of ICIs. ICIs can break up the immunologic homeostasis and reduce T-cell tolerance. Therefore, inhibition of immune checkpoint can lead to the activation of autoreactive T-cells, resulting in various irAEs similar to autoimmune diseases. Gastrointestinal toxicity, endocrine toxicity, and dermatologic toxicity are common side effects. Neurotoxicity, cardiotoxicity, and pulmonary toxicity are relatively rare but can be fatal. ICI-related gastrointestinal toxicity, dermatologic toxicity, and hypophysitis are more common with anti- CTLA-4 agents. ICI-related pulmonary toxicity, thyroid dysfunction, and myasthenia gravis are more common with PD-1/PD-L1 inhibitors. Treatment with systemic steroids is the principal strategy against irAEs. The use of immune-modulatory agents should be considered in case of no response to the steroid therapy. Treatment under the supervision of multidisciplinary specialists is also essential, because the symptoms and treatments of irAEs could involve many organs. Thus, this review focuses on the mechanism, clinical presentation, incidence, and treatment of various irAEs.

• IMMUNE NETWORK
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• v.12 no.3
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• pp.89-95
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• 2012

Immune cells express toll-like receptors (TLRs) and respond to molecular patterns of various pathogens. CpG motif in bacterial DNA activates innate and acquired immune systems through binding to TLR9 of immune cells. Several studies reported that CpG can directly regulate B cell activation, differentiation, and Ig production. However, the role of CpG in B cell growth and Ig production is not fully understood. In this study, we analyzed the effect of CpG on the kinetics of mouse B cell viability, proliferation, and Igs production. Overall, CpG enhanced mouse B cell growth and production of Igs in a dose-dependent manner. Unlike LPS, 100 nM CpG (high dose) did not support TGF-${\beta}1$-induced IgA and IgG2b production. Moreover, 100 nM CpG treatment abrogated either LPS-induced IgM or LPS/TGF-${\beta}1$-induced IgA and IgG2b production, although B cell growth was enhanced by CpG under the same culture conditions. We subsequently found that 10 nM CpG (low dose) is sufficient for B cell growth. Again, 10 nM CpG did not support TGF-${\beta}1$-induced IgA production but, interestingly enough, supported RA-induced IgA production. Further, 10 nM CpG, unlike 100 nM, neither abrogated the LPS/TGF-${\beta}1$- nor the LPS/RA-induced IgA production. Taken together, these results suggest that dose of CpG is critical in B cell growth and Igs production and the optimal dose of CpG cooperates with LPS in B cell activation and differentiation toward Igs production.

• IMMUNE NETWORK
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• v.24 no.2
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• pp.14.1-14.26
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• 2024

The inflammatory response during cutaneous leishmaniasis (CL) involves immune and non-immune cell cooperation to contain and eliminate Leishmania parasites. The orchestration of these responses is coordinated primarily by CD4⁺ T cells; however, the disease outcome depends on the Th cell predominant phenotype. Although Th1 and Th2 phenotypes are the most addressed as steers for the resolution or perpetuation of the disease, Th17 cell activities, especially IL-17 release, are recognized to be vital during CL development. Th17 cells perform vital functions during both acute and chronic phases of CL. Overall, Th17 cells induce the migration of phagocytes (neutrophils, macrophages) to the infection site and CD8⁺ T cells and NK cell activation. They also provoke granzyme and perforin secretion from CD8⁺ T cells, macrophage differentiation towards an M2 phenotype, and expansion of B and Treg cells. Likewise, immune cells from the inflammatory infiltrate have modulatory activities over Th17 cells involving their differentiation from naive CD4⁺ T cells and further expansion by generating a microenvironment rich in optimal cytokines such as IL-1β, TGF-β, IL-6, and IL-21. Th17 cell activities and synergies are crucial for the resistance of the infection during the early and acute stages; however, if unchecked, Th17 cells might lead to a chronic stage. This review discusses the synergies between Th17 cells and the inflammatory infiltrate and how these interactions might destine the course of CL.