scholarly journals The lineage-defining factors T-bet and Bcl-6 collaborate to regulate Th1 gene expression patterns

2011 ◽  
Vol 208 (5) ◽  
pp. 1001-1013 ◽  
Author(s):  
Kenneth J. Oestreich ◽  
Albert C. Huang ◽  
Amy S. Weinmann

The T-box transcription factor T-bet is important for the differentiation of naive CD4+ T helper cells (Th cells) into the Th1 phenotype. Much is known about T-bet’s role as a transcriptional activator, but less is known about the mechanisms by which T-bet functionally represses alternative Th cell genetic programs. In this study, we first identify Socs1, Socs3, and Tcf7 (TCF-1) as gene targets that are negatively regulated by T-bet. Significantly, T-bet’s role in the repression of these genes is through a direct interaction with their promoters. Consistent with this, we identified two T-bet DNA-binding elements in the Socs1 promoter that are functionally used to down-regulate transcription in primary Th1 cells. Importantly, T-bet’s novel role in transcriptional repression is because of its ability to physically associate with, and functionally recruit, the transcriptional repressor Bcl-6 to a subset of promoters. Furthermore, T-bet functionally recruits Bcl-6 to the Ifng locus in late stages of Th1 differentiation to repress its activity, possibly to prevent the overproduction of IFN-γ, which could result in autoimmunity. Collectively, these data establish a novel mechanism for T-bet–mediated gene repression in which two lineage-defining transcription factors, one a classical activator and one a repressor, collaborate to promote and properly regulate Th1 development.

2002 ◽  
Vol 196 (7) ◽  
pp. 969-977 ◽  
Author(s):  
Andrea L. Wurster ◽  
Vikki L. Rodgers ◽  
Abhay R. Satoskar ◽  
Matthew J. Whitters ◽  
Deborah A. Young ◽  
...  

The cytokine potential of developing T helper (Th) cells is directly shaped both positively and negatively by the cytokines expressed by the effector Th cell subsets. Here we find that the recently identified cytokine, interleukin (IL)-21, is preferentially expressed by Th2 cells when compared with Th1 cells generated in vitro and in vivo. Exposure of naive Th precursors to IL-21 inhibits interferon (IFN)-γ production from developing Th1 cells. The repression of IFN-γ production is specific in that the expression of other Th1 and Th2 cytokines is unaffected. IL-21 decreases the IL-12 responsiveness of developing Th cells by specifically reducing both signal transducer and activator of transcription 4 protein and mRNA expression. These results suggest that Th2 cell-derived IL-21 regulates the development of IFN-γ–producing Th1 cells which could serve to amplify a Th2 response.


2004 ◽  
Vol 199 (4) ◽  
pp. 535-545 ◽  
Author(s):  
Takaaki Sugimoto ◽  
Yuriko Ishikawa ◽  
Tomohiro Yoshimoto ◽  
Nobuki Hayashi ◽  
Jiro Fujimoto ◽  
...  

Interleukin (IL)-18 was originally regarded to induce T helper cell (Th)1-related cytokines. In general, factors favoring interferon (IFN)-γ production are believed to abolish allergic diseases. Thus, we tested the role of IL-18 in regulation of bronchial asthma. To avoid a background response of host-derived T cells, we administered memory type Th1 or Th2 cells into unsensitized mice and examined their role in induction of bronchial asthma. Administration of antigen (Ag) induced both airway inflammation and airway hyperresponsiveness (AHR) in mice receiving memory Th2 cells. In contrast, the same treatment induced only airway inflammation but not AHR in mice receiving memory Th1 cells. However, these mice developed striking AHR when they were coadministered with IL-18. Furthermore, mice having received IFN-γ–expressing Th1 cells sorted from polarized Th1 cells developed severe airway inflammation and AHR after intranasal administration of Ag and IL-18. Thus, Th1 cells become harmful when they are stimulated with Ag and IL-18. Newly polarized Th1 cells and IFN-γ–expressing Th1 cells, both of which express IL-18 receptor α chain strongly, produce IFN-γ, IL-9, IL-13, granulocyte/macrophage colony-stimulating factor, tumor necrosis factor α, regulated on activation, normal T cell expressed and secreted, and macrophage inflammatory protein 1α upon stimulation with Ag, IL-2, and IL-18 in vitro. Thus, Ag and IL-18 stimulate memory Th1 cells to induce severe airway inflammation and AHR in the naive host.


1998 ◽  
Vol 188 (6) ◽  
pp. 1191-1196 ◽  
Author(s):  
Mark H. Kaplan ◽  
Andrea L. Wurster ◽  
Michael J. Grusby

The differentiation of T helper (Th) cells is regulated by members of the signal transducer and activator of transcription (STAT) family of signaling molecules. We have generated mice lacking both Stat4 and Stat6 to examine the ability of Th cells to develop in the absence of these two transcription factors. Stat4, Stat6−/− lymphocytes fail to differentiate into interleukin (IL)-4–secreting Th2 cells. However, in contrast to Stat4−/− lymphocytes, T cells from Stat4, Stat6−/− mice produce significant amounts of interferon (IFN)-γ when activated in vitro. Although Stat4, Stat6−/− lymphocytes produce less IFN-γ than IL-12–stimulated control lymphocytes, equivalent numbers of IFN-γ–secreting cells can be generated from cultures of Stat4, Stat6−/− lymphocytes activated under neutral conditions and control lymphocytes activated under Th1 cell–promoting conditions. Moreover, Stat4, Stat6−/− mice are able to mount an in vivo Th1 cell–mediated delayed-type hypersensitivity response. These results support a model of Th cell differentiation in which the generation of Th2 cells requires Stat6, whereas a Stat4-independent pathway exists for the development of Th1 cells.


2017 ◽  
Vol 44 (1) ◽  
pp. 57-63
Author(s):  
E. Krasimirova ◽  
D. Kyurkchiev

Abstract Systemic sclerosis (SSc) is a chronic progressive autoimmune disease characterized by skin and multiorgan involvement with alterations in both the innate and adaptive immunities. The hallmark of the disease is widespread fibrosis engaging the skin and multiple internal organs, as well as the musculoskeletal system. There is mounting evidence that T cells are key players in the pathogenesis of scleroderma. The current review discusses the role of the different T helper (Th) lymphocyte subsets in the processes of inflammation and fibrosis, characteristics for the pathogenesis of the disease. Cytokines produced by Th cell populations have a major effect on endothelial cells and fibroblasts in the context of favoring/inhibiting the vasculopathy and the fibrosis spread. The Th2 pro-fibrotic cytokines IL-4 and IL-13 have been shown to induce collagen synthesis by fibroblasts, whereas IFN-γ demonstrates an inhibitory effect. Increased Th17 cells are present in the scleroderma skin infiltrates. The combination of IL-17, IFN-γ and TGF-β levels in CD45RO and CD45RA cells from patients with SSc is useful to distinguish between the limited and the diffuse phenotype of the disease. There are accumulating data for functional and numerical alterations in the Tregs in SSc. High levels of TNF-α which might reduce the suppressive ability of Tregs have been described. According to some studies, the number of Tregs in scleroderma skin biopsies has been decreased against the normal absolute number of Tregs in peripheral blood of the same patients, which suggests suppressed immunomodulatory response. Other studies reported increased frequency of Tregs in peripheral blood of patients with systemic sclerosis and established a correlation with disease activity. The main immunological challenge remains the identification of the trigger of the autoimmune response in SSc, the causes for preferential Th2-type cell responses and the immunological differences between the diffuse and the limited cutaneous form of the disease.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3762-3762
Author(s):  
Guangsheng He ◽  
Xiuli Wang ◽  
De Pei Wu ◽  
Aining Sun ◽  
Zhengming Jin

Abstract Objectives To explore the subsets and function of T helper (Th) in bone marrow of the patients with immune related pancytopenia(IRP). Methods The CD4+ cells producing IFN-γ or IL-4 in cytoplasm were defined as Th1 or Th2 cells respectively. All these cells in bone marrow were measured from 16 normal controls, 25 untreated IRP patients; The mRNA expressions of IL-4, IL-10, IFN-γ and IL-2 genes in unstimulated bone marrow mononuclear cells(BMMNC)from 25 untreated IRP patients, 10 normal controls were measured by reverse transcription polymerase chain reaction (RT-PCR). Results The percentage of Th1 cells, Th2 cells and ratio of Th1/Th2 in bone marrow of normal controls was: 0.42%, 0.24%, 1.57 respectively, and the percentage of Th1 cells in untreated patients with IRP was 0.58%, which was not markedly different from the that of normal controls(t=0.903, P>0.05). But the percentage of Th2 cells of the patients with IRP was significantly higher than that of normal controls(t=4.673, P<0.01), and the balance of Th1/Th2 shifted to Th2 more significantly by comparing to that of normal controls (t=4.880, P<0.01). The mRNA expressions of IL-4 and IL-10 in the Th2 cells of the untreated IRP patients were significantly higher than those of the normal controls, however difference of the expressions of IFN-γ and IL-2 in the Th1 cells were not significantly. Conclusions The percentage of Th2 cells increased in the patients with IRP, and the balance of Th1/Th2 shifted to Th2. And the expression of Th2 type cytokines was more frequent in IRP. The imbalance of subtypes of Th lymphocytes and hyperfunction of Th2 lymphocytes might play important roles in the pathogenic mechanism of IRP, which lead to more B lymphocytes and producing autoantibodies consistenly.


1997 ◽  
Vol 185 (5) ◽  
pp. 817-824 ◽  
Author(s):  
Susanne J. Szabo ◽  
Anand S. Dighe ◽  
Ueli Gubler ◽  
Kenneth M. Murphy

The developmental commitment to a T helper 1 (Th1)- or Th2-type response can significantly influence host immunity to pathogens. Extinction of the IL-12 signaling pathway during early Th2 development provides a mechanism that allows stable phenotype commitment. In this report we demonstrate that extinction of IL-12 signaling in early Th2 cells results from a selective loss of IL-12 receptor (IL-12R) β2 subunit expression. To determine the basis for this selective loss, we examined IL-12R β2 subunit expression during Th cell development in response to T cell treatment with different cytokines. IL-12R β2 is not expressed by naive resting CD4+ T cells, but is induced upon antigen activation through the T cell receptor. Importantly, IL-4 and IFN-γ were found to significantly modify IL-12 receptor β2 expression after T cell activation. IL-4 inhibited IL-12R β2 expression leading to the loss of IL-12 signaling, providing an important point of regulation to promote commitment to the Th2 pathway. IFN-γ treatment of early developing Th2 cells maintained IL-12R β2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-γ production. Thus, IFN-γ may prevent early Th cells from premature commitment to the Th2 pathway. Controlling the expression of the IL-12R β2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.


1999 ◽  
Vol 67 (12) ◽  
pp. 6249-6256 ◽  
Author(s):  
David W. Pascual ◽  
David M. Hone ◽  
Stacy Hall ◽  
Frederik W. van Ginkel ◽  
Masafumi Yamamoto ◽  
...  

ABSTRACT Protective immunity to enterotoxigenic Escherichia coli(ETEC) is antibody (Ab) dependent; however, oral immunization with purified ETEC fimbriae fails to elicit protective immunity as a consequence of antigenic alteration by the gastrointestinal (GI) tract. Unless unaltered ETEC fimbriae can reach the inductive lymphoid tissues of the GI tract, immunity to ETEC cannot be induced. To produce immunity, live vectors, such as Salmonella typhimurium, can effectively target passenger antigens to the inductive lymphoid tissues of the GI tract. By convention, oral immunizations withSalmonella vectors induce CD4+ T helper (Th) cell responses by gamma interferon (IFN-γ)-dominated pathways both to the vector and passenger antigen, resulting in serum immunoglobulin G2a (IgG2a) and modest mucosal IgA Ab responses. In the present study, mice orally immunized with a Salmonella vector engineered to stably express ETEC colonization factor antigen I (CFA/I) showed initially elevated serum IgG1 and mucosal IgA anti-CFA/I Ab responses. As expected, mice orally immunized with an E. coli-CFA/I construct elicited poor anti-CFA/I Ab responses. In fact, the addition of cholera toxin during oral E. coli-CFA/I immunization failed to greatly enhance mucosal IgA Ab responses. Seven days after immunization with the Salmonella-CFA/I construct, cytokine-specific ELISPOT showed induction of predominant Th2-type responses in both mucosal and systemic immune compartments supporting the early IgG1 and IgA anti-CFA/I Abs. By 4 weeks, the Th cell response became Th1 cell dominant from the earlier Th2-type responses, as evidenced by increased mucosal and systemic IFN-γ-producing T cells and a concomitant elevation of serum IgG2a Ab responses. This biphasic response offers an alternative strategy for directingSalmonella vector-induced host immunity along a Th2 cell-dependent pathway, allowing for early promotion of mucosal and systemic Abs.


1997 ◽  
Vol 185 (3) ◽  
pp. 439-452 ◽  
Author(s):  
Irina M. Conboy ◽  
Rosemarie H. DeKruyff ◽  
Keri M. Tate ◽  
Zhu A. Cao ◽  
Tom A. Moore ◽  
...  

Development of T helper cell (Th)1 or Th2 cytokine responses is essential for effector and regulatory functions of T helper cells. We have compared cytokine profiles of myelin basic protein (MBP) Ac1-16 peptide-specific T helper cells from inbred mouse strains expressing identical k haplotype-derived MHC class II molecules B10.A and B10.BR. B10.BR T cell lines (TCL) produced Th1 cytokines (including high levels of TNF-α) and induced experimental autoimmune encephalomyelitis after adoptive transfer. In contrast, B10.A TCL produced Th2 cytokines (including low levels of TNF-α) and were poorly encephalitogenic. The contributions of the genetic origin of the T cells and the APC were explored. Serial restimulations of the B10.BR TCL with B10.A or (B10.A × B10.BR) F1 splenic antigen presenting cells (APC) during the establishment of TCL markedly reduced both Th1 cytokine production and encephalitogenicity. In addition, a single restimulation with B10.A splenic APC reduced IFN-γ and TNF-α production by established Th1 MBP-specific Ak-restricted B10.BR TCL and by a Th1 KLH-specific, Ek-restricted B10.BR T cell clone. These studies suggest that B10.A and B10.BR APC differ in their ability to stimulate IFN-γ and TNF-α production by mature Th1 cells and also influence their Th1/Th2 commitment in vivo. The nature of the downregulatory activity of B10.A APC on IFN-γ and TNF-α production was explored. 2-hour supernatants from antigen-activated B10.A APC/TCL cultures or from B10.A APC activated by LPS had the same inhibitory effects on IFN-γ and TNF-α production by B10.BR TCL. The downregulatory effects of B10.A APC are independent of TNF-α, IL-4, IL-10, IL-12p40, IFN-γ, IL-13, TGF-β, and PGE2. Thus, genetic difference(s) between B10.A and B10.BR APC appear(s) to control the production or activity of a novel soluble cytokine regulatory factor that influences Th1/Th2 commitment and controls production of IFN-γ and TNF-α by mature Th1 cells.


1988 ◽  
Vol 168 (2) ◽  
pp. 543-558 ◽  
Author(s):  
R Fernandez-Botran ◽  
V M Sanders ◽  
T R Mosmann ◽  
E S Vitetta

Murine Th1 and Th2 subsets differ not only in the lymphokines they produce, but also functionally. It is not clear what factors influence the preferential activation of one subset versus the other and what regulatory interactions exist between them. The purpose of this study was to examine the effect of lymphokines produced by clones of Th1 cells (IL-2 and IFN-gamma), Th2 cells (IL-4), and APC (IL-1) on the proliferative response of Th1 and Th2 cells after antigenic stimulation. Activation of both types of clones in the presence of antigen and APC resulted in the acquisition of responsiveness to the proliferative effects of both IL-2 and IL-4, although Th2 cells were more responsive to IL-4 than Th1 cells. Responsiveness of Th1 and Th2 cells to both lymphokines decreased with time after initial antigenic activation; Th1 cells lost their responsiveness to IL-4 more rapidly and to IL-2 more slowly than Th2 cells. IFN-gamma partially inhibited the IL-2 and IL-4-mediated proliferation of Th2, but not Th1 cells. Although the presence of IL-1 was not required for the response of Th1 or Th2 cells to IL-4, its presence resulted in a synergistic effect with IL-2 or IL-4 in Th2 but not in Th1 cells. Both subsets responded to a mixture of IL-2 and IL-4 in synergistic fashion. Delayed addition and wash-out experiments indicated that both IL-2 and IL-4 had to be present simultaneously in order for synergy to occur. These results suggest that Th cell subsets might regulate each other via the lymphokines that they secrete and that the pathways of IL-2 and IL-4 mediated proliferation are interrelated.


2018 ◽  
Vol 19 (10) ◽  
pp. 3120
Author(s):  
Jae Jeon ◽  
Byung-Cheol Lee ◽  
Doman Kim ◽  
Daeho Cho ◽  
Tae Kim

A flavonoid Astragalin (kaempferol-3-O-β-d-glucopyranoside, Ast) has several biological activities including anti-oxidant, anti-HIV, and anti-allergic effects. Nonetheless, its insolubility in hydrophilic solvents imposes restrictions on its therapeutic applications. In this study, we investigated the effects of water-soluble astragalin-galactoside (kaempferol-3-O-β-d-isomaltotrioside, Ast-Gal) on murine bone marrow-derived dendritic cell (DC) maturation and T helper (Th) cell-mediated immune responses. Ast-Gal significantly increased maturation and activation of DCs through the upregulation of surface markers, such as cluster of differentiation (CD)80, CD86, and Major histocompatibility complex (MHC) II in a dose-dependent manner, while Ast had little effects. Additionally, Ast-Gal-treated DCs markedly secreted immune-stimulating cytokines such as interleukin (IL)-1β, IL-6, and IL-12. Importantly, Ast-Gal strongly increased expression of IL-12, a polarizing cytokine of Th1 cells. In a co-culture system of DCs and CD4+ T cells, Ast-Gal-treated DCs preferentially differentiates naïve CD4+ T cells into Th1 cells. The addition of neutralizing IL-12 monoclonal antibody (mAb) to cultures of Ast-Gal-treated DCs and CD4+ T cells significantly decreased interferon (IFN)-γ production, thereby indicating that Ast-Gal-stimulated DCs enhance the Th1 response through IL-12 production by DCs. Injection with Ast-Gal-treated DCs in mice increased IFN-γ-secreting Th1 cell population. Collectively, these findings indicate that hydrophilically modified astragalin can enhance Th1-mediated immune responses via DCs and point to a possible application of water-soluble astragalin-galactoside as an immune adjuvant.


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