• Title/Summary/Keyword: immune tolerance,

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Oral Administration of Phosphorylated Dextran Regulates Immune Response in Ovalbumin-Immunized Mice

  • Nagasawa, Chiho;Nishimura-Uemura, Junko;Tohno, Masanori;Shimosato, Takeshi;Kawai, Yasushi;Ikegami, Shuji;Oda, Munehiro;Saito, Tadao;Kitazawa, Haruki
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.1
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    • pp.106-115
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    • 2010
  • Phosphorylated dextran (P-Dex) is an acidic polysaccharide that functions as an immune adjuvant. P-Dex is known to regulate immune response by maintaining a balance between Th1 and Th2 cells in vitro, and thus may also be important in the control of allergic reactions. In the current study, we report the optimum conditions required for the efficient phosphorylation of dextran without toxicity. We found that when dextran was heated at 160${^{\circ}C}$ for 24 h in phosphate buffer (pH 5.0), the resulting P-Dex demonstrated the highest phosphorus content (6.8%). We also report that P-Dex enhances mitogenic activity in mouse splenocytes and induces expression of CD69 and CD86 on the surface of B cells and dendritic cells (DC) in vitro. Oral administration of P-Dex to ovalubmin (OVA)-immunized mice was found to reduce antigen-induced cell proliferation and suppress the expression of CD86 on Th2-inducing DC via exogenous OVA stimulation. P-Dex was also found to increase IL-10 expression in the splenocytes of treated mice. These findings suggest that oral administration of P-Dex increases immunological tolerance and improves the specificity of immunological response to specific antigens.

Characterization of Anti-anti-idiotypic Antibodies (Ab3) Induced by Immunization of Anti-idiotypic Antibodies (Ab2) Mimicking Disialoganglioside GD2 (Disialoganglioside GD2의 Anti-idiotypic Antibody (Ab2)에 의해 유도된 Anti-anti-idiotypic Antibodies (Ab3)의 특성)

  • Park, Yoon-Sun
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.118-125
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    • 2003
  • Background: Disialoganglioside GD2 is a tumor-associated antigen that is overexpressed on tumor cells of neuroectodermal origin, such as melanoma and neuroblastoma. Anti-idiotypic antibodies that mimic GD2 may induce more effective immune responses than GD2 antigen itself, because they are protein antigens and are known to be able to break immune tolerance. In this study, to explore the potential of anti-idiotypic antibodies as tumor vaccines, the ability of anti-idiotypic antibodies (Ab2) to induce anti-anti-idiotypic antibodies (Ab3) that bind to the original antigen GD2 was investigated. Methods: Six monoclonal anti-idiotypic antibodies (1A8, 1G5, 2B6, 3A4, 3D6, 3H9) to monoclonal antibody M2058, which is a monoclonal antibody to GD2, were produced in mice. Three (1A8, 3A4, 3H9) of them were selected based on their ability to inhibit the binding of Ab1 to D142.34 (murine melanoma cell expressing GD2). These 3 different Ab2 were injected into rabbits, and rabbit Ab3 induced by each of them were characterized. Results: Ab3-containing sera from two rabbits immunized with 1A8, 3A4, or 3H9 bound significantly (P<0.05) to D142.34 but not to B78.96 (GD2-negative cell), and bound significantly (P<0.05) to isolated GD2 but not to GD1a. Ab3-containing sera from two rabbits immunized with 3A4 or 3H9 inhibited significantly (P<0.05) the binding of Ab1 M2058 to D142.34, and inhibited significantly (P<0.05) the binding of Ab1 M2058 to the Ab2. Conclusion: These results suggest that anti-idiotypic antibodies 3A4 and 3H9 have a potential to be used as vaccines against tumors expressing GD2 by inducing GD2-specific antibodies (Ab3).

Increased Frequency of Foxp3+ Regulatory T Cells in Mice with Hepatocellular Carcinoma

  • Du, Yong;Chen, Xin;Huang, Zhi-Ming;Ye, Xiao-Hua;Niu, Qing
    • 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.

Association of CD4+CD25+FoxP3+ regulatory T cells with natural course of childhood chronic immune thrombocytopenic purpura

  • Son, Bo Ra;Kim, Ji Yoon
    • Clinical and Experimental Pediatrics
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    • v.58 no.5
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    • pp.178-182
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    • 2015
  • Purpose: The purpose of this study was to determine the frequency of $CD4^+CD25^+FoxP3^+$ regulatory T cells (Treg) in the peripheral blood of patients with childhood chronic immune thrombocytopenic purpura (ITP) exhibiting thrombocytopenia and spontaneous remission. The findings of this study indicate the possibility of predicting spontaneous recovery and pathogenesis of childhood chronic ITP. Methods: Eleven children with chronic ITP (seven thrombocytopenic and four spontaneous remission cases; mean age, 8.8 years; range, 1.7-14.9 years) were enrolled in this study. Five healthy children and eight healthy adults were included as controls. The frequency of Treg was evaluated by flow cytometry in the peripheral blood. Results: In this study, four patients (36%) achieved spontaneous remission within 2.8 years (mean year; range, 1.0-4.4 years). The frequency of Treg was significantly lower in patients with persisting thrombocytopenia ($0.13%{\pm}0.09%$, P<0.05), than that in the patients with spontaneous remission ($0.30%{\pm}0.02%$), healthy adults controls ($0.55%{\pm}0.44%$), and healthy children controls ($0.46%{\pm}0.26%$). A significantly positive correlation was found between the frequency of Treg and the platelet count in children. Conclusion: These data suggest that a lower frequency of Treg contributes to the breakdown of self-tolerance, and may form the basis for future development of specific immunomodulatory therapies. Furthermore, Treg frequency has prognostic implication toward the natural course and long-term outcomes of childhood chronic ITP.

Characterization of Lactobacillus reuteri BCLR-42 and Lactobacillus plantarum BCLP-51 as novel dog probiotics with innate immune enhancing properties

  • Kim, Eun Jin;Kang, Yeong Im;Bang, Tae Il;Lee, Myoung Han;Lee, Sang Won;Choi, In Soo;Song, Chang Seon;Lee, Joong Bok;Park, Seung Yong
    • Korean Journal of Veterinary Research
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    • v.56 no.2
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    • pp.75-84
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    • 2016
  • Probiotics that are able to provide beneficial effects on animal health have become important ingredients of dog foods. This study was conducted to characterize the probiotic potentials of two strains, Lactobacillus reuteri BCLR-42 and Lactobacillus plantarum BCLP-51, that were derived from feces of healthy dogs and evaluated based on tolerance to low pH and bile acid, antimicrobial activities, enzyme profiles, sensitivity to antibiotics, and innate immune enhancing potentials. Both strains showed survival of more than 90% at pH 3 and 0.2% bile acid and exhibited broad antimicrobial activities against indicator bacteria. Moreover, both strains showed high sensitivity to antibiotics, except vancomycin, metronidazole, and gentamicin. The alkaline phosphatase was negligible (score 0), whereas they showed strong beta galactosidase activity (score range 5 or 3, respectively). The phagocytosis and oxidative burst activities of canine granulocytes were significantly enhanced in response to both strains. These results show that both strains have the capability to act as probiotics and the potential for application as ingredients in dog foods.

miR-195/miR-497 Regulate CD274 Expression of Immune Regulatory Ligands in Triple-Negative Breast Cancer

  • Yang, Lianzhou;Cai, Yuchen;Zhang, Dongsheng;Sun, Jian;Xu, Chenyu;Zhao, Wenli;Jiang, Wenqi;Pan, Chunhua
    • Journal of Breast Cancer
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    • v.21 no.4
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    • pp.371-381
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    • 2018
  • Purpose: Immune suppression is common in patients with advanced breast cancer but the mechanisms underlying this phenomenon have not been sufficiently studied. In this study, we aimed to identify B7 family members that were able to predict the immune status of patients, and which may serve as potential targets for the treatment of breast cancer. We also aimed to identify microRNAs that may regulate the expression of B7 family members. Methods: The Cancer Genome Atlas data from 1,092 patients with breast cancer, including gene expression, microRNA expression and survival data, were used for statistical and survival analyses. Polymerase chain reaction and Western blot were used to measure messenger RNA and protein expression, respectively. Luciferase assay was used to investigate direct microRNA target. Results: Bioinformatic analysis predicted that microRNA (miR)-93, miR-195, miR-497, and miR-340 are potential regulators of the immune evasion of breast cancer cells, and that they exert this function by targeting CD274, PDCD1LG2, and NCR3LG1. We chose CD274 for further investigations. We found that miR-195, miR-497, and CD274 expression levels were inversely correlated in MDA-MB-231 cells, and miR-195 and miR-497 expressions mimic inhibited CD274 expression in vitro. Mechanistic investigations demonstrated that miR-195 and miR-497 directly target CD274 3' untranslated region. Conclusion: Our data indicated that the level of B7 family members can predict the prognosis of breast cancer patients, and miR-195/miR-497 regulate CD274 expression in triple negative breast cancer. This regulation may further influence tumor progression and the immune tolerance mechanism in breast cancer and may be able to predict the effect of immunotherapy on patients.

Peripheral Generation of $CD4^+CD25^+Foxp3^+$ Regulatory T Cells

  • Kim, Byung-Seok;Park, Young-Jun;Kang, Chang-Yuil
    • IMMUNE NETWORK
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    • v.7 no.1
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    • pp.1-9
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    • 2007
  • [ $CD4^+CD25^+$ ] regulatory T cells (Tregs) expressing the lineage-specific marker Foxp3 represent an important regulatory T cell that is essential for maintaining peripheral tolerance. Although it was believed that Treg development is solely dependent on the thymus, accumulating evidence demonstrates that Tregs can also be induced in the periphery. Considering the various origins of peripherally developed $CD4^+CD25^+Foxp3^+$ regulatory T cells, it seems likely that multiple factors are involved in the peripheral generation of Tregs.

Anticonvulsant potential of some traditional medicinal plants

  • Asif, Mohammad
    • CELLMED
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    • v.4 no.1
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    • pp.1.1-1.13
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    • 2014
  • Epilepsy has now become the most serious brain disorder. A number of synthetic antiepileptic drugs are available in practice, however their effectiveness does not grip true with the entire population suffering from epilepsy. Traditional systems of medicine are popular in developing countries and most of the population relies on traditional medicines for their primary health care need. Medicinal plants to be an important source of traditional medicines. Various plants are used for the treatment of epilepsy in traditional system of medicines and various plants are yet to be scientifically investigated. Phyto-constituents have been the basis of treatment of human diseases including epilepsy. Herbal products are extensively used for the treatment of many diseases worldwide and where allopathic fails or has severe side effects. Psycho neural drugs are also have very serious side effects like physical dependence, tolerance, deterioration of cognitive function and effect on respiratory, digestive and immune system. So the treatments through herbal medicines are widely used across the world due to their wide applicability and therapeutic efficacy with least side effects, which in turn has accelerated the research regarding natural therapy. In this review we have summarized some herbal anti-epileptics.

The role of hepatic stellate cells in fibrotic liver diseases

  • Cho, Hye Jin;Jang, Jae Young;Kim, Tae Min
    • Journal of Animal Reproduction and Biotechnology
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    • v.35 no.2
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    • pp.113-118
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    • 2020
  • Hepatic stellate cells (HSCs) play essential roles in normal and pathophysiological function in liver. In steady state, HSCs contribute to retinoid storage, immune tolerance, and extracellular matrix (ECM) homeostasis. Upon liver injury, they become activated and lead to morphological and functional changes. Studies have demonstrated that activation of HSCs by various stimuli such as toxins, microbial infection, or metabolic overload can promote the fibrotic changes in liver by production of ECM. Herein, we provide current knowledge about the basic characteristics of HSCs and the mechanism by which they are activated.

Anticonvulsant potential of some medicinal plants and their beneficial properties

  • Asif, Mohammad
    • CELLMED
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    • v.3 no.4
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    • pp.27.1-27.13
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    • 2013
  • Epilepsy has now become the most serious brain disorder. A number of synthetic antiepileptic drugs are available in practice, however their effectiveness does not grip true with the entire population suffering from epilepsy. Traditional systems of medicine are popular in developing countries and most of the population relies on traditional medicines for their primary health care need. Medicinal plants to be an important source of traditional medicines. Various plants are used for the treatment of epilepsy in traditional system of medicines and various plants are yet to be scientifically investigated. Phytoconstituents have been the basis of treatment of human diseases including epilepsy. Herbal products are extensively used for the treatment of many diseases worldwide and where allopathic fails or has severe side effects. Psycho neural drugs are also have very serious side effects like physical dependence, tolerance, deterioration of cognitive function and effect on respiratory, digestive and immune system. So the treatments through herbal medicines are widely used across the world due to their wide applicability and therapeutic efficacy with least side effects, which in turn has accelerated the research regarding natural therapy. In this review we have summarized some herbal antiepileptics.