• IMMUNE NETWORK
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• v.8 no.1
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• pp.21-28
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• 2008

Background: A co-inhibitory molecule, B7-H4, is believed to negatively regulate T cell immunity by suppressing T cell proliferation and inhibiting cytokine production. However, the mechanism behind B7-H4-mediated tolerance remains unclear. Methods: Balb/c $(H-2^d)$ mice were fed with dendritic cell line, DC2.4 $(H-2^d)$ every day for 10 days. Meantime, mice were hydrodynamically injected with recombinant plasmid expressing B7-H4 fusion protein (B7-H4.hFc) or hFc via tail vein. One day after last feeding, mice were immunized with allogeneic B6 spleen cells. 14 days following immunization, mice were challenged with B6 spleen cells to ear back and the ear swelling was determined the next day. Subsequently, a mixed lymphocyte reaction (MLR) was also performed and cytokines profiles from the reaction were examined by sandwich ELISA. Frequency of immunosuppressive cell population was assayed with flow cytometry and mRNA for FoxP3 was determined by RT-PCR. Results: Tolerant mice given plasmid expressing B7-H4.hFc showed a significant reduction in ear swelling compared to control mice. In addition, T cells from mice given B7-H4.hFc plasmid revealed a significant hyporesponsiveness of T cells against allogeneic spleen cells and showed a significant decrease in Th1 and Th2 cytokines such as IFN-${\gamma}$, IL-5, and TNF-${\alpha}$. Interestingly, flow cytometric analysis showed that the frequency of CD4+CD25+FoxP3+ Tregs in spleen was increased in tolerant mice given recombinant B7-H4.hFc plasmid compared to control group. Conclusion: Our results demonstrate that B7-H4 synergistically potentiates oral tolerance induced by allogeneic cells by increasing the frequency of FoxP3+ CD4+CD25+ Treg and reducing Th1 and Th2 cytokine production.

• Journal of Life Science
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• v.28 no.1
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• pp.17-25
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• 2018

In this study, we examined the efficacy of the immune regulation of ${\beta}$-1,3/1,6-glucan and Lactobacillus plantarum LM1004 on atopic dermatitis models. The oral administration of ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 on mice significantly decreased the amount of scratching, leakage to evans blue, and concentrations of serum immunoglobulin E (IgE) and histamine compared with the atopic dermatitis - induced group. When atopic dermatitis was induced, the transcription factors (GATA-3, retinoic acid-related orphan receptor ${\gamma}$ T [$ROR{\gamma}T$]) and cytokines (interleukin-4 [IL-4], IL-17) of Th2 and Th17 cells were overexpressed at the transcriptional level, and they significantly decreased with oral administration of ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004. In addition, ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 were shown to modulate the immune balance by increasing the expression of Th1 and Treg transcription (T-bet, forkhead box p3 [Foxp3]) and cytokines (interferon-${\gamma}$ [IFN-${\gamma}$], transforming growth factor-${\beta}$ [TGF-${\beta}$]). Galectin-9 and filaggrin were significantly lower in the atopic dermatitis - induced group and significantly higher in the ${\beta}$-1,3/1,6-glucan-treated group. In contrast, thymic stromal lymphopoietin (TSLP) was highest in the atopic dermatitis-induced group, while mice that were orally administered ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 showed similar TSLP levels to the control group. These results indicate that ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 have immunomodulatory effects and atopic dermatitis improvement effects in an animal model of atopic dermatitis. Therefore, it is expected that ${\beta}$-1,3/1,6-glucan and L. plantarum LM1004 can be used as natural materials in the treatment of atopic dermatitis.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.439-444
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• 2017

The ability of nematodes to manipulate the immune system of their host towards a Th2 and T regulatory responses has been proposed to suppress the inflammatory response. Clinical trials have proposed a useful effect of helminth infections on improvement of inflammatory disorders. In this study, we investigated the immunomodulatory effect of Syphacia obvelata infection to induce intestinal tolerance in C57BL/6 mice. Mice were infected through the cagemates with self-infected BALB/c mice. Four weeks post-infection, expression levels of $IFN-{\gamma}$, $TNF-{\alpha}$, IL-17, and IL-10 were assessed in the supernatant of mesenteric lymph node (MLN) culture. $Foxp3^+Treg$ were measured in MLN cells by flow cytometry. In the S. obvelata-infected group, the percentage of Tregs ($5.2{\pm}0.4$) was significantly higher than the control ($3.6{\pm}0.5$) (P<0.05). The levels of IL-10 ($55.3{\pm}2.2$ vs $35.2{\pm}3.2$), IL-17 ($52.9{\pm}3.8$ vs $41{\pm}1.8$), $IFN-{\gamma}$ ($44.8{\pm}4.8$ vs $22.3{\pm}2.3$) and $TNF-{\alpha}$ ($71.1{\pm}5.8$ vs $60.1{\pm}3.3$) were significantly increased in infected mice compared to the control group (P<0.05). The above results showed the potential effects of S. obvelata to induce intestinal tolerance. Therefore, it seems that S. obvelata may increase the immunological suppressive function in the intestinal tract.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.141-152
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• 2016

The demand to develop more safe and efficient methods for treating allergic patient is now continuously growing due to the increasing prevalence of allergic diseases. Probiotics are endogenous microbial flora that gives health benefits within hosts. Probiotics are now considered as one of solutions to treat allergic patients since recent evidence shows that some of probiotics have immunomodulatory function. Also, the treatment of probiotics to patients is relatively safer than other anti-inflammatory agents. In this review, we summarized on immunomodulatory function of some probiotics which show preventive or therapeutic effects on major allergic diseases such as atopic dermatitis, allergic rhinitis, asthma, or food allergy. Based on previous literature, the treatment of probiotics can alleviate the symptoms of allergic diseases via balancing $Th_1/Th_2$ response or increasing the number of regulatory T ($T_{reg}$) cells.

• Food Science and Industry
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• v.52 no.3
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• pp.261-271
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• 2019

Gut microbiome have recently provided evidence that the gut microbiota are capable of greatly influencing all aspects of physiology and immunology. Although a number of recent studies have shown that probiotics can modulate gut microbiota structure, the mechanism underlying this effect remains to be elucidated. In a disease state, the relative abundances of beneficial gut bacteria are generally reduced, which is restored by constant probiotic supplementation. Oral administration of probiotics improved the disease state by (1) inducing differentiation and function of regulatory T cells, (2) reducing inflammatory response, (3) modulating the gut environment, and (4) increasing the proportions of short-chain fatty acid- or beneficial metabolite-producing gut microbiota including the genera Bifidobacterium, Faecalibacterium, Akkermansia, etc. In this review, current knowledge on how probiotics can influence host's health by altering gut microbiota structure and on how probiotics and beneficial gut bacteria can be applied as next-generation probiotics will be discussed.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.482-489
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• 2021

Background: Asthma is an incurable hyper-responsive disease of the pulmonary system that is caused by various allergens, including indoor and outdoor stimulators. According to the Global Asthma Network, 339 million people suffered from asthma in 2018, with particularly severe forms in children. Numerous treatments for asthma are available; however, they are frequently associated with adverse effects such as growth retardation, neurological disorders (e.g., catatonia, poor concentration, and insomnia), and physiological disorders (e.g., immunosuppression, hypertension, hyperglycemia, and osteoporosis). Methods: Korean Red Ginseng has long been used to treat numerous diseases in many countries, and we investigated the anti-asthmatic effects and mechanisms of action of Korean Red Ginseng. Eighty-four BALB/c mice were assigned to 6 treatment groups: control, ovalbumin-induced asthma group, dexamethasone treatment group, and 3 groups treated with Korean Red Ginseng water extract (KRGWE) at 5, 25, or 50 mg/kg/day for 5 days. Anti-asthmatic effects of KRGWE were assessed based on biological changes, such as white blood cell counts and differential counts in the bronchoalveolar lavage fluid, serum IgE levels, and histopathological changes in the lungs, and by examining anti-asthmatic mechanisms, such as the cytokines associated with Th1, Th2, and Treg cells and inflammation pathways. Results: KRGWE affected ovalbumin-induced changes, such as increased white blood cell counts, increased IgE levels, and morphological changes (mucous hypersecretion, epithelial cell hyperplasia, inflammatory cell infiltration) by downregulating cytokines such as IL-12, IL-4, and IL-6 via GATA-3 inactivation and suppression of inflammation via NF-κB/COX-2 and PGE₂ pathways. Conclusion: KRGWE is a promising drug for asthma treatment.

• Food Science and Industry
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• v.55 no.3
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• pp.276-283
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• 2022

Vitamin D is a fat-soluble vitamin helps to retain calcium and phosphorus but also has shown to affect immune regulation and homeostasis. In humans, vitamin D3 and vitamin D2 and their metabolite has intensively studied in both innate and adaptive immune system that they are important to regulate overwhelmed inflammation. The vitamin D receptor is a nuclear hormone receptor which regulate various downstream target gene expressions as a transcription factor related to metabolism, immune regulation, etc. Vitamin D deficiency is a high-risk factor for inflammatory diseases like autoimmune disease and allergy. In addition, reduced vitamin D seem to correlate with susceptibility to the virus infection such as HIV and COVID-19. In this review, we will summarize up-to-date vitamin D's role in various immune cells, immune regulatory functions during autoimmune, allergic, and infectious diseases. We will also discuss about vitamin D supplement effects in human trial studies for COVID-19.