• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3815-3819
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• 2012

The CD4+CD25+ regulatory T cell (Treg) is a special kind of T cell subset. Studies have showed that Treg cells are involved in a number of physiological processes and pathologic conditions such as autoimmune diseases, transplantation tolerance and cancer. Tregs with unique capacity for immune inhibition can impair anti-tumour immunity and help tumor cells to escape from immune surveillance. The aim of our study was to investigate whether Tregs are involved in hepatocellular carcinoma (HCC). A BABL/C mouse with HCC in situ model was established to evaluate the Treg existence in carcinoma tissues and the changes of Tregs in spleen using flow cytometry and immunohistochemistry methods. Granzyme B expression in carcinoma tissues was analyzed by immunohistochemistry to investigate the tumor local immune status.The proportion of CD4+CD25+/CD4+ spleen lymphocytes of tumor bearing mice ($18.8%{\pm}1.26%$) was found to be significantly higher than that in normal mice ($9.99%{\pm}1.90%$) (P<0.01 ). Immunohistochemistry of spleen tissue also confirmed that there was an increase in Treg in tumor-bearing mice, while in carcinomas it showed Treg cells to be present in tumor infiltrating lymphocyte areas while Granzyme B was rarely observed. Anti-tumour immunity was suppressed, and this might be associated with the increase of Tregs. Our observations suggest that the CD4+CD25+Treg/CD4+ proportion in spleen lymphocytes can be a sensitive index to evaluate the change of Tregs in hepatocellular carcinoma mice and the Treg may be a promising therapeutic target for cancer.

• BMB Reports
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• v.37 no.6
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• pp.635-641
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• 2004

Interferons regulate a number of biological functions including control of cell proliferation, generation of antiviral activities and immumodulation in human cells. Studies by several investigators have identified a number of cellular signaling cascades that are activated during engagement of interferon receptors. The activation of multiple signaling cascades by the interferon receptors appears to be critical for the generation of interferon mediated biological functions and immune surveillance. The present review summarizes the existing knowledge on the multiple signaling cascades activated by Type I interferons. Recent developments in this research area are emphasized and the implications of these new discoveries on our understanding of interferon actions are discussed.

• Journal of Cancer Prevention
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• v.22 no.4
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• pp.203-210
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• 2017

After transcription, RNAs are always associated with RNA binding proteins (RBPs) to perform biological activities. RBPs can interact with target RNAs in sequence- and structure-dependent manner through their unique RNA binding domains. In development and progression of carcinogenesis, RBPs are aberrantly dysregulated in many human cancers with various mechanisms, such as genetic alteration, epigenetic change, noncoding RNA-mediated regulation, and post-translational modifications. Upon deregulation in cancers, RBPs influence every step in the development and progression of cancer, including sustained cell proliferation, evasion of apoptosis, avoiding immune surveillance, inducing angiogenesis, and activating metastasis. To develop therapeutic strategies targeting RBPs, RNA interference-based oligonucleotides or small molecule inhibitors have been screened based on reduced RBP-RNA interaction and changed level of target RNAs. Identification of binding RNAs with high-throughput techniques and integral analysis of multiple datasets will help us develop new therapeutic drugs or prognostic biomarkers for human cancers.

• BMB Reports
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• v.54 no.7
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• pp.344-355
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• 2021

Mucins are high molecular-weight epithelial glycoproteins and are implicated in many physiological processes, including epithelial cell protection, signaling transduction, and tissue homeostasis. Abnormality of mucus expression and structure contributes to biological properties related to human cancer progression. Tumor growth sites induce inhospitable conditions. Many kinds of research suggest that mucins provide a microenvironment to avoid hypoxia, acidic, and other biological conditions that promote cancer progression. Given that the mucus layer captures growth factors or cytokines, we propose that mucin helps to ameliorate inhospitable conditions in tumor-growing sites. Additionally, the composition and structure of mucins enable them to mimic the surface of normal epithelial cells, allowing tumor cells to escape from immune surveillance. Indeed, human cancers such as mucinous carcinoma, show a higher incidence of invasion to adjacent organs and lymph node metastasis than do non-mucinous carcinoma. In this mini-review, we discuss how mucin provides a tumor-friendly environment and contributes to increased cancer malignancy in mucinous carcinoma.

• BMB Reports
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• v.54 no.6
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• pp.285-294
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• 2021

The lymphatic vasculature plays important role in regulating fluid homeostasis, intestinal lipid absorption, and immune surveillance in humans. Malfunction of lymphatic vasculature leads to several human diseases. Understanding the fundamental mechanism in lymphatic vascular development not only expand our knowledge, but also provide a new therapeutic insight. Recently, Hippo-YAP/TAZ signaling pathway, a key mechanism of organ size and tissue homeostasis, has emerged as a critical player that regulate lymphatic specification, sprouting, and maturation. In this review, we discuss the mechanistic regulation and pathophysiological significant of Hippo pathway in lymphatic vascular development.

• IMMUNE NETWORK
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• v.16 no.3
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• pp.195-199
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• 2016

Fecal samples obtained from wild boar habitats are useful for the surveillance of diseases in wild boar populations; however, it is difficult to determine the species of origin of feces collected in natural habitats. In this study, a fecal IgA ELISA was evaluated as a method for identifying the porcine species from fecal samples. Both domestic pigs (Sus scrofa domestica) and wild boars (Sus scrofa coreanus) showed significantly higher levels of fecal IgA than other animal species. Additionally, age dependent changes in the level of Ig A in wild boars and domestic pigs were identified; Titers of Ig A were highest in suckling period and lowest in weanling period.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.346-351
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• 1999

Tumor cells may alter the expression of proteins involved in antigen processing and presentation, allowing them to avoid recognition and elimination by cytotoxic T cells. In order to investigate whether the major histocompatibility complex (MHC) class I-mediated antigen processing machinery is preserved in human lung cancer cell lines, we examined the expression of multiple components of the MHC class I antigen processing pathway, including transporter associated with antigen processing (TAP), $\beta_2$-microglobulin, MHC class I molecules, and chaperones which have not been previously examined in this context. Row cytometry analysis showed that the cell surface expression of MHC class I molecules was downregulated in all of the cell lines. While some cell lines showed no detectable expression of MHC class I molecules, pulse-chase experiments showed that MHC class I molecules were synthesized in the other cell lines but not transported from the endoplasmic reticulum to the cell surface. Low or nondetectable levels of TAP1 and/or TAP2 expression were demonstrated by Western blot analysis in all of the cell lines, representing a variety of lung tissue types. In some cases, this was accompanied by loss of tapasin expression. Our findings suggest that downregulation of antigen processing may be one of the strategies used by tumors to escape immune surveillance. This study provides further information for designing the potential therapeutic applications such as immunotherapy and gene therapy against cancers.

• Natural Product Sciences
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• v.13 no.2
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• pp.123-127
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• 2007

We investigated effect of small black soybean fraction (SBSF) T cell-mediated responses for tumor surveillance and proliferation in leukemia cells in vitro. Each SBSF butanol fraction (SBSFBu) and SBSF chloroform fraction (SBSFCh) was administered p.o. once a day far 21 days in BALB/c mice and then levels of serum cytokines and subpopulation of lymphocytes were measured. Moreover, SBSF fraction was treated into the cultured various cell lines for proliferation in leukemia cell lines, NO production by RAW264.7 cells, and expression of p53 gene in U937 leukemia cells. These results showed that SBSFBu increased levels of serum IL-4but not IL-2 and IFN-${\gamma}$, and increased expression of CD4$^+$ T cells and CD8$^+$ T cells in splenocytes in vivo, while SBSFCh increased levels of serum IL-2 and IFN-${\gamma}$ but decreased IL-4, and increased CD8$^+$ T cells but not CD4$^+$ T cells. Moreover, both of SBSFBu and SBSFCh inhibited proliferation of HL60, U937, and L1210 leukemia cell lines in a dose-dependent manner, up-regulated NO production by RAW264.7 cells in a dose-dependent manner, and enhanced expression of p53 gene in U937 leukemia cells. Our findings indicate that SBSFBu and SBSFCh may enhance T cell-dependent immune responses, and that both of SBSFBu and SBSFCh may inhibit proliferation of leukemia cells by up-regulation of NO production and expression of p53 gene.

• Journal of Microbiology and Biotechnology
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• v.33 no.7
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• pp.864-874
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• 2023

Natural killer (NK) cell dysfunctions against hepatocellular carcinoma (HCC) in a hypoxic environment. Many solid tumors are present in a hypoxic condition, which changes the effector function of various immune cells. The transcription of hypoxic-inducible factors (HIFs) in cancer cells make it possible to adapt to their hypoxic environment and to escape the immune surveillance of NK cells. Recently, the correlation between the transcription of HIF-1α and pro-inflammatory cytokines has been reported. Interleukin (IL)-6 is higher in cancers with a highly invasive ability, and is closely related to the metastasis of cancers. This study showed that the expression of HIF-1α in HCC cells was associated with the presence of IL-6 in the environment of HCC-NK cells. Blocking of IL-6 by antibody in the HCC-NK interaction changed the production of several cytokines including TGF-β, IL-1, IL-18 and IL-21. Interestingly, in a co-culture of HIF-1α-expressed HCC cells and NK cells, blocking of IL-6 increased the production of IL-21 in their supernatants. In addition, the absence of IL-6 significantly enhanced the cytotoxic ability and the expression of the activating receptors (NKG2D, NKp44, and NKG2C) in NK cells to HIF-1α-expressed HCC cells. These effects might be made by the decreased expression of HIF-1α in HCC cells through the inhibited phosphorylation of STAT3. In conclusion, the absence of IL-6 in the interaction of HIF-1α-expressed HCC cells and NK cells could enhance the antitumor activity of NK cells to HCC cells.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.39.1-39.18
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• 2021

The high virulent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that emerged in China at the end of 2019 has generated novel coronavirus disease, coronavirus disease 2019 (COVID-19), causing a pandemic worldwide. Every country has made great efforts to struggle against SARS-CoV-2 infection, including massive vaccination, immunological patients' surveillance, and the utilization of convalescence plasma for COVID-19 therapy. These efforts are associated with the attempts to increase the titers of SARS-CoV-2 neutralizing Abs (nAbs) generated either after infection or vaccination that represent the body's immune status. As there is no standard therapy for COVID-19 yet, virus eradication will mainly depend on these nAbs contents in the body. Therefore, serological nAbs neutralization assays become a requirement for researchers and clinicians to measure nAbs titers. Different platforms have been developed to evaluate nAbs titers utilizing various epitopes sources, including neutralization assays based on the live virus, pseudovirus, and neutralization assays utilizing recombinant SARS-CoV-2 S glycoprotein receptor binding site, receptor-binding domain. As a standard neutralization assay, the plaque reduction neutralization test (PRNT) requires isolation and propagation of live pathogenic SARS-CoV-2 virus conducted in a BSL-3 containment. Hence, other surrogate neutralization assays relevant to the PRNT play important alternatives that offer better safety besides facilitating high throughput analyses. This review discusses the current neutralization assay platforms used to evaluate nAbs, their techniques, advantages, and limitations.