• IMMUNE NETWORK
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• 제8권4호
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• pp.107-123
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• 2008

It has now been well documented in a variety of models that T regulatory T cells (Treg cells) play a pivotal role in the maintenance of self-tolerance, T cell homeostasis, tumor, allergy, autoimmunity, allograft transplantation and control of microbial infection. Recently, Treg cell are isolated and can be expanded in vitro and in vivo, and their role is the subject of intensive investigation, particularly on the possible Treg cell therapy for various immune-mediated diseases. A growing body of evidence has demonstrated that Treg cells can prevent or even cure a wide range of diseases, including tumor, allergic and autoimmune diseases, transplant rejection, graft-versus-host disease. Currently, a large body of data in the literature has been emerging and provided evidence that clear understanding of Treg cell work will present definite opportunities for successful Treg cell immunotherapy for the treatment of a broad spectrum of diseases. In this Review, I briefly discuss the biology of Treg cells, and summarize efforts to exploit Treg cell therapy for autoimmune diseases. This article also explores recent observations on pharmaceutical agents that abrogate or enhance the function of Treg cells for manipulation of Treg cells for therapeutic purpose.

• IMMUNE NETWORK
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• 제13권1호
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• pp.25-29
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• 2013

Ribavirin is an antiviral drug used in combination with pegylated interferon-${\alpha}$ (IFN-${\alpha}$) for the treatment of hepatitis C virus (HCV) infection. Recently, ribavirin was reported to inhibit the suppressive activity of regulatory T (Treg) cells. In the present study, we re-evaluated the effect of ribavirin on $CD4^+$ $CD4^+$ $CD25^+$ Treg cells from normal donors. First, we examined the expression of CTLA-4 and CD39, which are known to play a role in the suppressive function of Treg cells. We found that ribavirin treatment did not modulate the expression of CTLA-4 and CD39 in Treg cells. We also studied the effect of ribavirin on Treg cells in the presence of IFN-${\alpha}$; however, the expression of CTLA-4 and CD39 in Treg cells was not changed by ribavirin in the presence of IFN-${\alpha}$. Next, we directly evaluated the effect of ribavirin on the suppressive activity of Treg cells in the standard Treg suppression assay, by co-culturing CFSE-labeled non-Treg $CD4^+$ T cells with purified Treg cells. We found that ribavirin did not attenuate the suppressive activity of Treg cells. Taken together, while ribavirin reversed Treg cell-mediated suppression of effector T cells in the previous study, we herein demonstrate that ribavirin does not impair the suppressive activity of Treg cells.

• IMMUNE NETWORK
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• 제9권6호
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• pp.209-235
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• 2009

There has been an explosion of literature focusing on the role of regulatory T (Treg) cells in cancer immunity. It is becoming increasingly clear that Treg cells play an active and significant role in the progression of cancer, and have an important role in suppressing tumor-specific immunity. Thus, there is a clear rationale for developing clinical strategies to diminish their regulatory influences, with the ultimate goal of augmenting antitimor immunity. Therefore, manipulation of Treg cells represent new strategies for cancer treatment. In this Review, I will summarize and review the explosive recent studies demonstrating that Treg cells are increased in patients with malignancies and restoration of antitumor immunity in mice and humans by depletion or reduction of Treg cells. In addition, I will discuss both the prognostic value of Treg cells in tumor progression in tumor-bearing hosts and the rationale for strategies for therapeutic vaccination and immunotherapeutic targeting of Treg cells with drugs and microRNA.

• 대한이식학회지
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• 제31권4호
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• pp.157-169
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• 2017

Regulatory T cells (Treg) naturally rein in immune attacks, and they can inhibit rejection of transplanted organs and even reverse the progression of autoimmune diseases in mice. The initial safety trials of Treg against graft-versus-host disease (GVHD) provided evidence that the adoptive transfer of Treg is safe and capable of limiting disease progression. Supported by such evidence, numerous clinical trials have been actively investigating the efficacy of Treg targeting autoimmune diseases, type I diabetes, and organ transplant rejection, including kidney and liver. The limited quantity of Treg cells harvested from peripheral blood and subsequent in vitro culture have posed a great challenge to large-scale clinical application of Treg; nevertheless, the concept of CAR (chimeric antigen receptor)-Treg has emerged as a potential resolution to the problem. Recently, two CAR-T therapies, tisagenlecleucel and axicabtagene ciloleucel, were approved by the US FDA for the treatment of refractory or recurrent acute lymhoblastic leukemia. This approval could serve as a guideline for the production protocols for other genetically engineered T cells for clinical use as well. The phase I and II clinical trials of these agents has demonstrated that genetically engineered and antigen-targeting T cells are safe and efficacious in humans. In conclusion, both the promising results of Treg cell therapy from the clinical studies and the recent FDA approval of CAR-T therapies are paving the way for CAR-Treg therapy in clinical use.

• Biomolecules & Therapeutics
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• 제25권2호
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• pp.130-139
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• 2017

$CXCR5^+$ T follicular helper (Tfh) cells are associated with aberrant autoantibody production in patients with antibody-mediated autoimmune diseases including lupus. Follicular regulatory T (Tfr) cells expressing CXCR5 and Bcl6 have been recently identified as a specialized subset of $Foxp3^+$ regulatory T (Treg) cells that control germinal center reactions. In this study, we show that retroviral transduction of CXCR5 gene in $Foxp3^+$ Treg cells induced a stable expression of functional CXCR5 on their surface. The Cxcr5-transduced Treg cells maintained the expression of Treg cell signature genes and the suppressive activity. The expression of CXCR5 as well as Foxp3 in the transduced Treg cells appeared to be stable in vivo in an adoptive transfer experiment. Moreover, Cxcr5-transduced Treg cells preferentially migrated toward the CXCL13 gradient, leading to an effective suppression of antibody production from B cells stimulated with Tfh cells. Therefore, our results demonstrate that enforced expression of CXCR5 onto Treg cells efficiently induces Tfr cell-like properties, which might be a promising cellular therapeutic approach for the treatment of antibody-mediated autoimmune diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4607-4610
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• 2013

The aim of this study was evaluated the prevalence of Treg cells in peripheral blood in patients with gastric cancer, and investigate the effect of gastric cancer cells on their differentiation. ELISA was employed to assess the concentrations of TGF-${\beta}$ and IL-10 in gastric cancer patients' serum. Then, mouse gastric cancer cells were co-cultured with T lymphocytes or T lymphocytes + anti-TGF-${\beta}$. Flow cytometric analysis and RT-PCR were then performed to detect Treg cells and TGF-${\beta}$ and IL-10 expression in gastric cancer cells. Our data showed that the expression of TGF-${\beta}$ and IL-10 in the patients with gastric cancer was increased compared to the case with healthy donors. The population of Treg cells and the expression levels of TGF-${\beta}$ and IL-10 in the co-culture group were much higher than in the control group (18.6% vs 9.5%) (P<0.05). Moreover, the population of Treg cells and the expression levels of TGF-${\beta}$ and IL-10 in the co-culture systerm were clearly decreased after addition of anti-TGF-${\beta}$ (7.7% vs 19.6%) (P<0.01). In conclusion, gastric cancer cells may induce Treg cell differentiation through TGF-${\beta}$, and further promote immunosuppression.

• IMMUNE NETWORK
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• 제11권6호
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• pp.336-341
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• 2011

T cell receptor (TCR) signaling plays a critical role in T cell development, survival and differentiation. In the thymus, quantitative and/or qualitative differences in TCR signaling determine the fate of developing thymocytes and lead to positive and negative selection. Recently, it has been suggested that self-reactive T cells, escape from negative selection, should be suppressed in the periphery by regulatory T cells (Tregs) expressing Foxp3 transcription factor. Foxp3 is a master factor that is critical for not only development and survival but also suppressive activity of Treg. However, signals that determine Treg fate are not completely understood. The availability of mutant mice which harbor mutations in TCR signaling mediators will certainly allow to delineate signaling events that control intrathymic (natural) Treg (nTreg) development. Thus, we summarize the recent progress on the role of TCR signaling cascade components in nTreg development from the studies with murine model.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1721-1724
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• 2013

Objective: To investigate the effect of epirubicin on soluble CD25 (sCD25) secretion by CD4+CD25+ regulatory T (Treg) cells isolated from diffuse large B-cell lymphoma (DLBCL) patients. Methods: Treg cells were isolated from the peripheral blood mononuclear cells isolated from the newly diagnosed DBLCL patients. The concentration of sCD25 in the supernatant was determined with a commercial sCD25 (IL-2R) enzyme-linked immunosorbent assay (ELISA) kit. The fluorescence intensity of CD25 was detected by flow cytometry. Results: Cell survival rate was significantly decreased along with the increase of epirubicin concentration after treatment for 24 h. There was also a significant difference in the concentration of sCD25 between the epirubicin group and the control group (P<0.01). A positive correlation between the Treg cells survival rate and the concentration of sCD25 was detected (r=0.993, P<0.01). When equal numbers of CD4+CD25+ Treg cells of the epirubicin group and the control group were cultured for another 24 h without epirubicin the CD25 fluorescence intensity on the surface of Treg cells was obviously higher in the epirubicin group than that in the control group (P<0.01), while the sCD25 concentration in the supernatant in the epirubicin group was significantly lower than that in the control group (P<0.05). Conclusion: Epirubicin may improve the body's immune functions by inhibiting the sCD25 secretion by Treg cells in DLBCL patients.

• 대한임상검사과학회지
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• 제50권3호
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• pp.304-312
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• 2018

본 연구에서는 면역 억제 역할을 하는 것으로 알려져 있는 조절 T 세포 (regulatory T cell, Treg)의 새로운 생리학적 기능 대하여 확인해보고자 하였다. 시험관내나 동물실험에서 조절 T 세포가 분비하는 transforming growth factor ${\beta}1$ ($TGF-{\beta}1$)에 의하여 이식 직전까지 췌장섬세포의 생존률을 향상시키면서 동시에 혈당조절 기능이 향상될 수 있을 것이라는 가설이다. 이를 증명하기 위하여 마우스를 이용한 1형 당뇨병 모델을 제작한 뒤, 180 IEQ (islet equivalents)의 췌장섬세포를 동종간 이식하였다. 췌장섬세포는 이식 수술 시행 전까지 48시간 동안 $4{\times}10^6$의 Treg 세포와 함께 배양하여 Treg 유래 $TGF-{\beta}1$에 충분히 노출시킨 뒤 사용하였다. Treg 단독군, 췌장섬세포 단독군 및 Treg/islet 동시 배양군에서 각각 $TGF-{\beta}1$, IL-6 및 인슐린 분비 수준의 변화를 측정하였다. Treg/islet 동시 배양군에서 IL-6와 인슐린 분비는 증가하였고 (P<0.0005, P<0.005), 췌장섬세포 단독군과 비교하여 생존율이 향상되었다(P<0.005). 또한, 이식 후, 동시 배양된 췌장섬세포는 1형 당뇨병 마우스 모델에서 혈당 수치를 보다 효율적으로 조절하였다. 이러한 결과는 Treg 세포가 $TGF-{\beta}1$ 분비를 통하여 췌장섬세포의 기능과 생존력을 향상시킬 수 있음을 시사한다.

• Molecules and Cells
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• 제44권5호
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• pp.318-327
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• 2021

CD4+ T helper (Th) cells play a crucial role in the modulation of innate and adaptive immune responses through the differentiation of Th precursor cells into several subsets, including Th1, Th2, Th17, and regulatory T (Treg) cells. Effector Th and Treg cells are distinguished by the production of signature cytokines and are important for eliminating intracellular and extracellular pathogens and maintaining immune homeostasis. Stimulation of naive Th cells by T cell receptor and specific cytokines activates master transcription factors and induces lineage specification during the differentiation of Th cells. The master transcription factors directly activate the transcription of signature cytokine genes and also undergo post-translational modifications to fine-tune cytokine production and maintain immune balance through cross-regulation with each other. This review highlights the post-translational modifications of master transcription factors that control the differentiation of effector Th and Treg cells and provides additional insights on the immune regulation mediated by protein argininemodifying enzymes in effector Th cells.