• IMMUNE NETWORK
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• v.16 no.1
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• pp.1-12
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• 2016

Th2 cell immunity is required for host defense against helminths, but it is detrimental in allergic diseases in humans. Unlike Th1 cell and Th17 cell subsets, the mechanism by which dendritic cells modulate Th2 cell responses has been obscure, in part because of the inability of dendritic cells to provide IL-4, which is indispensable for Th2 cell lineage commitment. In this regard, immune cells other than dendritic cells, such as basophils and innate lymphoid cells, have been suggested as Th2 cell inducers. More recently, multiple independent researchers have shown that specialized subsets of dendritic cells mediate Th2 cell responses. This review will discuss the current understanding related to the regulation of Th2 cell responses by dendritic cells and other immune cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.3
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• pp.548-556
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• 2006

This study was to evaluate the effect of Samjayangchin-tang (STYCT) on mouse Th1 and Th2 cells' differentiation and ovalbumin (OVA)-induced allergic inflammation. The proliferation of mouse CD4 T cells and the secretion of Th1/Th2 cytokines under the influence of STYCT extract were measured as well as the amount of ${\beta}-hexosaminidase$ in RBL-2H3 cells and the levels of $TNF-{\alpha}$ and IL-6 secretion in Raw264.7 cells. BALB/c mice were orally administered with STYCT extract and simultaneously inoculated with OVA to induce allergic reaction and measure the level of total IgE, OVA-specific IgE and the production of IFN- g, IL-4, IL-5 by the spleen cells. When mouse CD4 T cell were stimulated with anti-CO3 and anti-CD28 for 48 hours in various concentrations of STYCT extract, it decreased proliferation of CD4 cells. CD4 T cells under Th1/Th2 polarizing conditions for 3 days with STYCT resulted in mild decrease of IFN- g in Th1 cells and significant decrease of IL-4 in Th2 cells. STYCT extract had a dose-dependent inhibitory effect on antigen-induced release of ${\beta}-hexosaminidase$ in RBL-2H3 cells. Treatment of STYCT extract on LPS stimulated Raw 264.7 cells showed dose-dependent decrease in IL-6 production. Oral administration of STYCT extract on OVA-induced allergic mice showed an inhibitory effect on the levels of total serum IgE and OVA-specific IgE by 53% and 44%, respectively. Culture of spleen cells with OVA resulted in significant increase of IFN- g by 54% and significant decrease of IL-4 and IL-5 by 42%, and 29%, respectively. The results show that STYCT does not strongly induce mouse T cells to transform into Th1 or Th2 but it has an anti-allergic effect in vitro, and that it also corrects the unbalance between the reactions of Th cells in allergic diseases.

• IMMUNE NETWORK
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• v.5 no.1
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• pp.16-22
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• 2005

Background: IL-18 was originally cloned as a IFN-${\gamma}$ inducing factor in primed T cells. In synergy with IL-12, IL-18 has been shown to induce strikingly high levels of IFN-${\gamma}$ production by T cells and to enhance Th1 development. Also this cytokine exerts induction of Th2 development through IL-4 induction. Methods: Resting $CD4^+$ T cells were sorted by negative selection and activated by anti-CD3 plus anti-CD28 Ab. Expression of IL-12 binding sites, IL-18 binding sites, IL-18R ${\alpha}$, and GATA-3 mRNA were analysed by FACS and RT-PCR, respectively. Results: Resting $CD4^+$ T cells expressed IL-18R ${\alpha}$ chain but not IL-18 binding sites, suggesting a lack of IL-18R ${\beta}$ expression. IL-18R ${\alpha}$ was maintained on the Th1 and Th2 committed cells. IL-18 binding sites were induced on the Th1 but not Th2 cells. Exposure of these cells to IL-18 led to up-regulation of GATA-3 mRNA expression only in Th2 committed cells. To elucidate the relationship between IL-18R ${\alpha}$ expression and GATA-3 induction by IL-18, Th1 and Th2 committed cells were further cultured in medium with or without IL-12 for 2 days. IL-12 binding sites were maintained on the Th1 and Th2 cells regardless of IL-12 treatment, but IL-18R a expression was rapidly down-regulated on the IL12-untreated Th2 cells which did not induce GATA-3 mRNA expression followed by IL-18 stimulation. Conclusion: IL-12 supports expression of IL-18R ${\alpha}$ and GATA-3 mRNA expression was induced by IL-18 through IL-18R ${\alpha}$ without expression of IL-18 binding site in Th2 cells.

• IMMUNE NETWORK
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• v.15 no.4
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• pp.199-205
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• 2015

T-bet is a critical transcription factor that regulates differentiation of Th1 cells from $CD4^+$ precursor cells. Since T-bet directly binds to the promoter of the IFN-${\gamma}$ gene and activates its transcription, T-bet deficiency impairs IFN-${\gamma}$ production in Th1 cells. Interestingly, T-bet-deficient Th cells also display substantially augmented the production of IL-2, a T cell growth factor. Exogenous expression of T-bet in T-bet deficient Th cells rescued the IFN-${\gamma}$ production and suppressed IL-2 expression. IFN-${\gamma}$ and IL-2 reciprocally regulate Th cell proliferation following TCR stimulation. Therefore, we examined the effect of T-bet on Th cell proliferation and found that T-bet deficiency significantly enhanced Th cell proliferation under non-skewing, Th1-skewing, and Th2-skewing conditions. By using IFN-${\gamma}$-null mice to eliminate the anti-proliferative effect of IFN-${\gamma}$, T-bet deficiency still enhanced Th cell proliferation under both Th1- and Th2-skewing conditions. Since the anti-proliferative activity of T-bet may be influenced by IL-2 suppression in Th cells, we examined whether T-bet modulates IL-2-independent cell proliferation in a non-T cell population. We demonstrated that T-bet expression induced by ecdysone treatment in human embryonic kidney (HEK) cells increased IFN-${\gamma}$ promoter activity in a dose dependent manner, and sustained T-bet expression considerably decreased cell proliferation in HEK cells. Although the molecular mechanisms underlying anti-proliferative activity of T-bet remain to be elucidated, T-bet may directly suppress cell proliferation in an IFN-${\gamma}$- or an IL-2-independent manner.

• IMMUNE NETWORK
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• v.10 no.1
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• pp.1-4
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• 2010

Asthma is characterized by chronic airway inflammation with intense eosinophil and lymphocyte infiltration, mucus hyperproduction, and airway hyperresponsiveness. Accumulating evidence indicates that antigen-specific Th2 cells and their cytokines such as IL-4, IL-5, and IL-13 orchestrate these pathognomonic features of asthma. In addition, we and others have recently shown that IL-17-producing $CD4^+$ T cells (Th17 cells) and IL-23, an IL-12-related cytokine that is essential for survival and functional maturation of Th17 cells, are involved in antigen-induced airway inflammation. In this review, our current understanding of the roles of IL-23 and Th17 cells in the pathogenesis of allergic airway inflammation will be summarized.

• 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.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.416-419
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• 2011

Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-${\gamma}$ (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.567-575
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• 2014

Resveratrol is a naturally occurring stilbene which is safe and well-described compound with a potent anti-inflammatory activity. Recent studies suggested that resveratrol suppressed various inflammation mediated diseases such as asthma, chronic colitis, rheumatoid arthritis, and type 1 diabetes. These studies indicated that resveratrol might directly modulate $CD4^+$ helper T cells (Th cells)-mediated immune responses. However, it is not fully elucidated whether resveratrol directly regulates $CD4^+$ Th cell activation and differentiation. In the present study, $CD4^+$ Th cells were purified from C57BL/6 and treated with various concentrations of resveratrol. We found that resveratrol directly suppressed $CD4^+$ Th cells activation, leading to a defect in T cell proliferation. When $CD4^+$ Th cells were treated with resveratrol, cytokine production was also significantly reduced in a dose dependent manner. In accordance with these results, resveratrol even inhibited $CD4^+$ Th cells differentiation into Th1, Th2 or Th17, which produces IFN-${\gamma}$, IL-4 or IL-17 respectively. We also found that resveratrol could induce apoptosis of $CD4^+$ T cells at a high concentration. Our data demonstrated that resveratrol inhibited directly $CD4^+$ Th cells activation and differentiation. It suggests that resveratrol could be an efficient therapeutic strategy for autoimmune diseases in which $CD4^+$ Th cells play a critical role.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2359-2362
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• 2014

Background: To investigate the effects of double radiofrequency hyperthermia on Th1/Th2 cells in esophageal cancer patients treated with radiotherapy. Materials and Methods: 22 patients with esophageal cancer were divided into a radiotherapy group (10 cases) and a combined group (double radiofrequency hyperthermia combined with radiotherapy group, 12 cases). Both groups received conventional radiotherapy using a cobalt-60 therapy apparatus (TD60-66Gy/30-33F). Patients in the combined group also underwent double radiofrequency hyperthermia (2F/W, 8-10F). Before and after treatment, Th1, Th2, Tc1 and Tc2 cells in peripheral blood were determined with flow cytometry. Results: In the radiotherapy group, Th1 cell contents before and after radiotherapy were $17.5{\pm}5.26%$ and $9.69{\pm}4.86%$, respectively, with a significant difference (p<0.01). The Th1/Th2 ratio was significantly decreased from $28.2{\pm}14.3$ to $16.5{\pm}10.4 $(p<0.01). In the combined group, Th1 cell content before radiotherapy was $15.9{\pm}8.18%$, and it increased to $18.6{\pm}8.84$ after radiotherapy (p>0.05), the Th1/Th2 ratio decreasing from $38.4{\pm}36.3$ to $28.1{\pm}24.0$ (p>0.05). Changes in Th2, Tc1 and Tc2 cell levels were not significant in the two groups before and after therapy (p>0.05). Conclusions: Double radiofrequency hyperthermia can promote the conversion from Th2 to Th1 cells, and regulate the balance of Th1/Th2 cells.

• Biomolecules & Therapeutics
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• v.29 no.2
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• pp.154-165
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• 2021

This study aimed to investigate whether the antidiabetic drugs dipeptidyl peptidase 4 (DPP4) inhibitors such as evogliptin and sitagliptin affect the membrane DPP4 (mDPP4) enzymatic activity and immune function of T helper1 (Th1) cells in terms of cytokine expression and cell profiles. The mDPP4 enzymatic activity, cytokine expression, and cell profiles, including cell counts, cell viability, DNA synthesis, and apoptosis, were measured in pokeweed mitogen (PWM)-activated CD4+CD26+ H9 Th1 cells with or without the DPP4 inhibitors, evogliptin and sitagliptin. PWM treatment alone strongly stimulated the expression of mDPP4 and cytokines such as interleukin (IL)-2, IL-10, tumor necrosis factor-alpha, interferon-gamma, IL-13, and granulocyte-macrophage colony stimulating factor in the CD4+CD26+ H9 Th1 cells. Evogliptin or sitagliptin treatment potently inhibited mDPP4 activity in a dose-dependent manner but did not affect either the cytokine profile or cell viability in PWM-activated CD4+CD26+ H9 Th1 cells. These results suggest that, following immune stimulation, Th1 cell signaling pathways for cytokine expression function normally after treatment with evogliptin or sitagliptin, which efficiently inhibit mDPP4 enzymatic activity in Th1 cells.