Expression Of BATF Research Articles

BATF-Interacting Proteins Dictate Specificity in Th Subset Activity.

The basic leucine zipper (bZIP) transcription factor BATF is expressed in multiple Th subsets and cooperates with other factors to regulate gene transcription. BATF activates lineage-specific cytokines in Th subsets, activating IL-9 in Th9 cells and IL-17 in Th17 cells, but not IL-9 or IL-17 in the reciprocal subset. The mechanism for this restricted activity is unclear. In this report, we define BATF binding partners that contribute to Th subset-specific functions. Although BATF and IRF4 are expressed in greater amounts in Th9 than Th17, increased expression of both factors is not sufficient to induce IL-9 in Th17 cells. BATF also requires heterodimer formation with Jun family members to bind DNA and induce gene expression. Using primary mouse T cell culture, we observed that JunB and c-Jun, but not JunD, promote IL-9 production in Th9 cells. Ectopic expression of BATF with either JunB or c-Jun generates modest, but significant, increases in IL-9 production in Th17 cells, suggesting that the low expression of Jun family members is one factor limiting the ability of BATF to induce IL-9 in Th17 cells. We further identified that Bach2 positively regulates IL-9 production by directly binding to the Il9 gene and by increasing transcription factor expression in Th9 cells. Strikingly, cotransduction of Bach2 and BATF significantly induces IL-9 production in both Th9 and Th17 cells. Taken together, our results reveal that JunB, c-Jun, and Bach2 cooperate with BATF to contribute to the specificity of BATF-dependent cytokine induction in Th subsets.

Immunomodulatory germline variation associated with the development of multiple primary melanoma (MPM)

Multiple primary melanoma (MPM) has been associated with a higher 10-year mortality risk compared to patients with single primary melanoma (SPM). Given that 3–8% of patients with SPM develop additional primary melanomas, new markers predictive of MPM risk are needed. Based on the evidence that the immune system may regulate melanoma progression, we explored whether germline genetic variants controlling the expression of 41 immunomodulatory genes modulate the risk of MPM compared to patients with SPM or healthy controls. By genotyping these 41 variants in 977 melanoma patients, we found that rs2071304, linked to the expression of SPI1, was strongly associated with MPM risk reduction (OR = 0.60; 95% CI = 0.45–0.81; p = 0.0007) when compared to patients with SPM. Furthermore, we showed that rs6695772, a variant affecting expression of BATF3, is also associated with MPM-specific survival (HR = 3.42; 95% CI = 1.57–7.42; p = 0.0019). These findings provide evidence that the genetic variation in immunomodulatory pathways may contribute to the development of secondary primary melanomas and also associates with MPM survival. The study suggests that inherited host immunity may play an important role in MPM development.

Transcription factor networks in aged naïve CD4 T cells bias lineage differentiation.

With reduced thymic activity, the population of naïve T cells in humans is maintained by homeostatic proliferation throughout adult life. In young adults, naïve CD4 T cells have enormous proliferative potential and plasticity to differentiate into different lineages. Here, we explored whether naïve CD4 T‐cell aging is associated with a partial loss of this unbiased multipotency. We find that naïve CD4 T cells from older individuals have developed a propensity to develop into TH9 cells. Two major mechanisms contribute to this predisposition. First, responsiveness to transforming growth factor β (TGFβ) stimulation is enhanced with age due to an upregulation of the TGFβR3 receptor that results in increased expression of the transcription factor PU.1. Secondly, aged naïve CD4 T cells display altered transcription factor profiles in response to T‐cell receptor stimulation, including enhanced expression of BATF and IRF4 and reduced expression of ID3 and BCL6. These transcription factors are involved in TH9 differentiation as well as IL9 transcription suggesting that the aging‐associated changes in the transcription factor profile favor TH9 commitment.

Single-cell transcriptome analysis reveals diverse islet-infiltrating T cell subsets and a role for BATF in promoting the diabetogenic activity of CD8 T cells

Abstract T cells infiltrate pancreatic islets and directly mediate the destruction of insulin-producing β cells during the development of type 1 diabetes (T1D). However, islet-infiltrating T cell differentiation states and functional diversity have not been completely defined. We used unbiased single-cell RNA sequencing analyses to define the phenotypic complexity of islet-infiltrating T cells in non-obese diabetic (NOD) mice. In the CD4 T cell compartment, we identified naïve, memory, and regulatory T cells, as well as multiple Il21 expressing effector subsets positive for markers indicative of Th1 and Tfh cells. In the CD8 T cell compartment, we identified naïve cells and two activated subsets defined by Slamf6 or Cxcr6 expression, respectively resembling the self-renewing progenitor cells and terminally differentiated effectors found during chronic lymphocytic choriomeningitis virus (LCMV) infection. Single-cell regulatory network inference and clustering (SCENIC) analysis revealed that regulon activity of several transcription factors with known roles in effector CD8 T cell function including Batf were turned on in the Slamf6+ and Cxcr6+ cells. Previous studies have shown that IL-21 induced BATF expression in CD8 T cells is critical to sustain their effector function against chronic LCMV infection. Similarly, we found lower BATF expression in activated islet CD8 T cells from NOD. Il21+/− compared to NOD mice. We further demonstrated that overexpression of BATF in β cell autoreactive CD8 T cells eliminated their need for IL-21 to cause T1D. Our results reveal phenotypically diverse and novel islet-infiltrating T cell subsets and suggest a model in which the IL-21-BATF pathway is critical for the diabetogenic activity of CD8 T cells.

BATF-interacting proteins dictate specificity in Th subset activity

Abstract The basic leucine zipper transcription factor BATF is expressed in multiple Th subsets and cooperates with other factors to regulate gene transcription. BATF activates lineage-specific cytokines in Th subsets, activating IL-9 in Th9 cells and IL-17 in Th17 cells. The mechanism for this restricted activity is unclear. In this report we define BATF binding partners that contribute to Th subset-specific functions. Although BATF and IRF4 are expressed in greater amounts in Th9 than Th17, increased expression of both factors is not sufficient to induce IL-9 in Th17 cells. BATF also requires heterodimer formation with Jun family members to bind DNA and induce gene expression. We observed that JunB and c-Jun, but not JunD, promote IL-9 production in Th9 cells. Ectopic expression of BATF with either JunB or c-Jun generates modest but significant increases in IL-9 production in Th17 cells, suggesting that the low expression of Jun family members is one factor limiting the ability of BATF to induce IL-9 in Th17 cells. We further identified that Bach2 positively regulates IL-9 production by directly binding to the Il9 gene and by increasing transcription factor expression in Th9 cells. Strikingly, co-transduction of Bach2 and BATF significantly induces IL-9 production in both Th9 and Th17 cell. Taken together, our results reveal that JunB, c-Jun and Bach2 cooperate with BATF to contribute to the specificity of BATF-dependent cytokine induction in Th subsets.

KIAA1211 plays an oncogenic role in human non-small cell lung cancer.

One of the main causes of cancer disease and death worldwide is lung cancer. Our study focused on the function of KIAA1211 in non-small cell lung cancer (NSCLC). According to the data about NSCLC patients that from the Cancer Genome Atlas (TCGA), we found that KIAA1211 in NSCLC (P=5.06E-06) was significantly higher than the adjacent normal. Lentivirus-mediated short hairpin RNA (shRNA) was used to knockdown BATF expression in the human A549 NSCLC cell line and assessed by RT-qPCR and Western blot. Cell proliferation was evaluated by MTT assay and Celigo imaging cytometry. Cell apoptosis were detected by Annexin V staining. The test results showed that KIAA1211-shRNA A549 and SPC-A-1 cells can inhibit cell proliferation, and the apoptosis rate of KIAA1211-shRNA group was significantly higher than that of the control group. Knockdown of KIAA1211 inhibited NSCLC progression in xenograft tumor model. In conclusion, KIAA1211 could regulate NSCLC cells proliferation and apoptosis in vitro and in vivo. KIAA1211 may serve as a potent target for the treatment of NSCLC.

Circular RNA circ_0034642 elevates BATF3 expression and promotes cell proliferation and invasion through miR-1205 in glioma

Growing evidence indicates that circular RNA (circRNA) plays an important role in the regulation of tumor biological behaviors. In this study, we aimed to explore the role of a novel circRNA, circ_0034642, in glioma. qRT-PCR was conducted to evaluate the levels of circ_0034642 in glioma tissues and cells. In addition, the clinical severity and prognostic role of circ_0034642 were illustrated. Functionally, loss and gain-of function assays were performed by CCK-8, colony-forming, flow cytometric and transwell experiments in glioma cells. Moreover, luciferase reporter assay was used to detect the mechanism of circ_0034642. Circ_0034642 was upregulated in glioma tissues and cell lines. Overexpressed circ_0034642 was correlated with adverse phenotypes in the patients with glioma. In addition, circ_0034642 could be regarded as a prognostic predictor for glioma patients. Moreover, circ_0034642 could promote cell proliferation, migratory and invasive capacities and inhibit cell apoptosis. For the mechanism investigation, circ_0034642 was proved to be a sponge of miR-1205, and miR-1205 could regulate BATF3 expression via targeting 3′UTR of BATF3. Rescue assays also illustrated that the oncogenic function of circ_0034642 is partly attributed to its modulation on miR-1205/BATF3 axis. Collectively, circ_0034642/miR-1205/BATF3 pathway may play an important role in glioma.

Batf3+ DCs and type I IFN are critical for the efficacy of neoadjuvant cancer immunotherapy

ABSTRACTNew clinical trials are now evaluating the efficacy of neoadjuvant immunotherapy in the context of primary tumor surgery. Using the orthotopic 4T1.2 mouse model of spontaneously metastatic mammary cancer, we have shown that neoadjuvant immunotherapy and surgery was superior in the generation of tumor-specific CD8+ T cells and eradication of lethal metastases compared to surgery followed by adjuvant immunotherapy. However, the importance of host Batf3 and type I interferon (IFN) for long-term survival of mice following neoadjuvant immunotherapy is unknown. Here we demonstrated that loss of Batf3+ DCs or type I IFN receptor blockade in 4T1.2 tumor-bearing mice treated with neoadjuvant anti-PD-1+anti-CD137 immunotherapy reduced long-term survival with a corresponding reduction in tumor-specific CD8+ T cells producing effector cytokines in the primary tumor and in the periphery. Interestingly, we found all high-risk stage III melanoma patients relapsing after adjuvant or neoadjuvant ipilimumab+nivolumab within the OpACIN trial (NCT02437279) displayed low expression of Batf3+ DC-associated genes in pre-treatment tumor biopsies. Further focus should now be placed on validating the requirement of an intratumoral Batf3+ DC gene signature for response to neoadjuvant immunotherapy.

Targeting the HTLV-I-Regulated BATF3/IRF4 Transcriptional Network in Adult T Cell Leukemia/Lymphoma

Adult Tcell leukemia/lymphoma (ATLL) is a frequently incurable disease associated with the human lymphotropic virus type I (HTLV-I). RNAi screening of ATLL lines revealed that their proliferation depends on BATF3 and IRF4, which cooperatively drive ATLL-specific gene expression. HBZ, the only HTLV-I encoded transcription factor that is expressed in all ATLL cases, binds to an ATLL-specific BATF3 super-enhancer and thereby regulates the expression of BATF3 and its downstream targets, including MYC. Inhibitors of bromodomain-and-extra-terminal-domain (BET) chromatin proteins collapsed the transcriptional network directed by HBZ and BATF3, and were consequently toxic for ATLL cell lines, patient samples, and xenografts. Our study demonstrates that the HTLV-I oncogenic retrovirus exploits a regulatory module that can be attacked therapeutically with BET inhibitors.

Abstract 5746: CRISPR9-mediated FGL2-KO in tumor cells impairs tumor progression in brain and triggers antitumor immune memory systematically via NF-κB dependent Batf3 expression in DCs

Abstract Brain cancer is the 10th leading cause of death in United States with increasing primary tumor morbidity and secondary brain metastasis morbidity. Glioblastoma (GBM) is most lethal brain tumor with less than 5% 5 years survival rate marked by significant resistance to majority of therapies targeting tumor cells or tumor microenvironment. Here we shown one approach to convert aggressive GBM cells to immunogenic tumor cells by knockout FGL2 in GBM cells to evoke efficient anti-tumor immunosurvilliance. FGL2 is an immunosuppressive molecule and its expression level is strongly correlated with glioma grade and poor diagnosis. FGL2 from GBM cells, but not from host cells, is essential for immune evasion dependent GBM progression using both preclinical GBM and brain metastatic tumor models. Knockout FGL2 in GBM cells completely abolish tumor progression of GBM models challenged with low or high number of tumor cells in immunocompetent mice and protect mice from tumor rechallenge in periphery. This eradication effect is impaired in immune deficient mice and CD8+ T cells depleted mice, but not in FGL2KO mice, showing the necessarily of immune system to eliminate FGL2KO tumor cells and the requirement of FGL2 in tumor cells to evade immunosurvilliance. To understand how the systemic CD8+ T cell-dependent anti-tumor response and memory was induced by FGL2KO GBM cells, we studied the impact of FGL2KO tumor cells on dendritic cells (DCs) which control immune response via its critical role in the generation of effective cytotoxic T lymphocyte (CTL) responses. Knockout FGL2 in GBM cells induced CD8a+/CD103+ DCs accumulation in brain in vivo; DCs proliferation and CD103+ DCs induction in vitro. In agreement with this discovery, knockout Batf3, a key transcription factor regulating CD8a+/CD103+ DCs, reverse the impact of FGL2KO in GBM cell in vivo. By molecule analysis, a novel signaling pathway was revealed that knockout FGL2 in GBM cells induce NF-κ B activation, and this activation induced Batf3 and associated CD103 expression in DCs. Therefore, target specific molecule in GBM cells, such as knockout FGL2, can convert aggressive GBM cells to immunogenic cells, pointing to new approach for immune therapy. Citation Format: Jun Yan, Qingnan Zhao, Konrad Gabrusiewicz, Ling-Yuan Kong, Longfei Huo, Xueqing Xia, Jun Wei, Jingda Xu, Eric Davis, Amy B. Heimberger, Shulin Li. CRISPR9-mediated FGL2-KO in tumor cells impairs tumor progression in brain and triggers antitumor immune memory systematically via NF-κB dependent Batf3 expression in DCs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5746.

BATF regulates the expression of Nfil3, Wnt10a and miR155hg for efficient induction of antibody class switch recombination in mice.

BATF functions in T cells and Bcells to control the host response to antigen and promote the production of class switched immunoglobulins. In this study, we demonstrate that BATF expression increases rapidly, and transiently, following Bcell stimulation and use an inducible murine model of BATF deletion to show that this induction is necessary, and sufficient, for immunoglobulin (Ig) class switch recombination (CSR). We examine two genes (Nfil3 and miR155gh) that are positively regulated, and one gene (Wnt10a) that is negatively regulated by BATF during CSR. These genes play essential roles in CSR and each impacts the expression and/or function of the others. Our observations allow these targets of BATF regulation to be positioned in a network upstream of the activation of germline transcripts (GLT) from the IgH locus and of transcriptional activation of Aicda - the gene encoding the enzyme directing Ig gene rearrangements. This work extends the knowledge of the molecular control of CSR and, importantly,positionsthe induction and function of BATFas an early eventin this process.

Immune-modulation of two BATF3 paralogues in rainbow trout Oncorhynchus mykiss

Basic leucine zipper transcription factor ATF-like (BATF) -3 is a member of the activator protein 1 (AP‑1) family of transcription factors and is known to play a vital role in regulating differentiation of antigen-presenting cells in mammals. In this study, two BATF3 homologues (termed BATF3a and BATF3b) have been identified in rainbow trout (Oncorhynchus mykiss). Both genes were constitutively expressed in tissues, with particularly high levels of BATF3a in spleen, liver, pyloric caecae and head kidney. BATF3a was also more highly induced by PAMPs and cytokines in cultured cells, with type II IFN a particularly potent inducer. In rIL-4/13 pre-stimulated cells, the viral PAMPS polyI:C and R848 had the most pronounced effect on BATF3 expression. BATF3 expression could also be modulated in vivo, following infection with Yersinia ruckeri, a bacterial pathogen causing redmouth disease in salmonids, or with the rhabdovirus IHNV. The results suggest that BATF3 may be functionally conserved in regulating the differentiation and activation of immune cells in lower vertebrates and could be explored as a potential marker for comparative investigation of leucocyte lineage commitment across the vertebrate phyla.

IL-18 from Batf3-dependent cells licenses natural killer cell IL-10 production during Listeria monocytogenes infection

Abstract Natural killer (NK) cells are innate lymphoid cells that regulate the immune response to infection through secretion of both pro- and anti-inflammatory cytokines. The pathogen Listeria monocytogenes (Lm) capitalizes on NK cell production of the anti-inflammatory cytokine interleukin (IL)-10 during establishment of severe infection. Lm-stimulated NK cell IL-10 limits immune cell recruitment and activation, allowing for bacterial expansion. Here, we report that IL-18 from dendritic cells (DCs) promotes this IL-10 production. IL-18 acts directly on NK cells to license IL-10 secretion that is independent of IL-12 and STAT4, which co-stimulate IFNγ secretion during Lm infection and can induce NK cell IL-10 in other contexts. DC release of IL-18 is driven by the Lm p60 virulence protein and requires DC expression of nlrp3 and batf3. Mice lacking nlrp3, il18, il18R, or batf3 fail to accumulate serum IL-10 and are highly resistant to systemic Lm infection. Our data thus show that during systemic infection Lm selectively targets Baft3-dependent cells to drive IL-18 release that licenses NK cell IL-10 production. Exploiting this previously-unappreciated pathway to promote IL-10 production enables Lm to dampen inflammatory and anti-microbial host responses.

The expression change of RORγt, BATF, and IL-17 in Chinese vitiligo patients with 308 nanometers excimer laser treatment.

This study aims to explore the expression of RORγt, BATF, and IL-17 in Chinese vitiligo patients with 308 nm excimer laser treatment. One hundred and sixty-four vitiligo patients treated with 308 nm excimer laser were enrolled as Case group and 137 health examiners as Control group. Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expressions of RORγt, BATF, and IL-17. Expression of RORγt, BATF, IL-17A, and IL-17F were higher in Case group than Control group, with the diagnostic accuracy of 88.04, 87.38, 97.34, and 89.04%, respectively. Pearson correlation analysis showed a positive correlation in RORγt, BATF, IL-17A, and IL-17F mRNAs in vitiligo patients. Moreover, their expressions were higher in active vitiligo patients than stable ones. Besides, the expressions of RORγt, BATF, IL-17A, and IL-17F in vitiligo skin were significantly higher than those in non lesional skin and normal controls. After treatment, their expressions were significantly decreased. Active vitiligo and the high expressions of RORγt, BATF, and IL-17F were the independent risk factors for the ineffectiveness of 308 nm excimer laser treatment. The expressions of RORγt, BATF, IL-17 were significantly enhanced in vitiligo patients, which were correlated with the activity of vitiligo and 308 nm excimer laser therapeutic effects.

The AP-1-BATF and -BATF3 module is essential for growth, survival and TH17/ILC3 skewing of anaplastic large cell lymphoma

Transcription factor AP-1 is constitutively activated and IRF4 drives growth and survival in ALK+ and ALK– anaplastic large cell lymphoma (ALCL). Here we demonstrate high-level BATF and BATF3 expression in ALCL. Both BATFs bind classical AP-1 motifs and interact with in ALCL deregulated AP-1 factors. Together with IRF4, they co-occupy AP-1-IRF composite elements, differentiating ALCL from non-ALCL. Gene-specific inactivation of BATFs, or global AP-1 inhibition results in ALCL growth retardation and/or cell death in vitro and in vivo. Furthermore, the AP-1-BATF module establishes TH17/group 3 innate lymphoid cells (ILC3)-associated gene expression in ALCL cells, including marker genes such as AHR, IL17F, IL22, IL26, IL23R and RORγt. Elevated IL-17A and IL-17F levels were detected in a subset of children and adolescents with ALK+ ALCL. Furthermore, a comprehensive analysis of primary lymphoma data confirms TH17–, and in particular ILC3-skewing in ALCL compared with PTCL. Finally, pharmacological inhibition of RORC as single treatment leads to cell death in ALCL cell lines and, in combination with the ALK inhibitor crizotinib, enforces death induction in ALK+ ALCL. Our data highlight the crucial role of AP-1/BATFs in ALCL and lead to the concept that some ALCL might originate from ILC3.

The critical role of Bach2 in regulating type 2 chronic airway inflammation.

Although Bach2 (broad complex-tramtrack-bric a brac and Cap'n'collar homology 2) plays an important role in regulating Th2 cell differentiation and type 2 immune responses, the underlying molecular mechanisms remain unclear. Our current studies demonstrate that Bach2 associates with Batf (basic leucine zipper transcription factor ATF-like) family transcription factors and binds to the regulatory regions of the Th2 cytokine gene loci. The Bach2-Batf complex antagonizes the recruitment of the interferon regulatory factor 4 (Irf4)-containing Batf complex to activator protein 1 (AP-1) motifs in the Th2 cytokine gene locus and suppresses Th2 cytokine production and/or Th2 cell differentiation. The deletion of Batf ameliorated the spontaneous development of type 2 airway inflammation that is found in mice with Bach2 deficiency specifically in T cells. Interestingly, Bach2 regulates Batf and Batf3 expression via two distinct pathways. First, the Bach2-Batf complex directly binds to the Batf and Batf3 gene loci and reduces transcription by interfering with the Batf-Irf4 complex. Second, Bach2 suppresses interleukin 4 (IL-4)-induced augmentation of Batf and Batf3 expression through the regulation of IL-4 production. These findings suggest that IL-4 and Batf family transcription factors form a positive feedback amplification loop to induce Th2 cell differentiation and that Bach2-Batf interactions block the formation of this amplification loop. Furthermore, we found that reductions in Bach2 confer an innate immunological function on CD4 T cells to induce antigen-independent cytokine production. Some Bach2-deficient lung CD4 T cells showed characteristic features similar to pathogenic Th2 cells, including IL-33 receptor expression and IL-33-dependent Th2 cytokine production. These results suggest a critical role for Bach2 in regulating Th2 cell differentiation and the subsequent onset of chronic type 2 inflammation.

Interleukin-12 from CD103+ Batf3-Dependent Dendritic Cells Required for NK-Cell Suppression of Metastasis.

Several host factors may affect the spread of cancer to distant organs; however, the intrinsic role of dendritic cells (DC) in controlling metastasis is poorly described. Here, we show in several tumor models that although the growth of primary tumors in Batf3-deficient mice, which lack cross-presenting DCs, was not different from primary tumors in wild-type (WT) control mice, Batf3-deficient mice had increased experimental and spontaneous metastasis and poorer survival. The increased metastasis was independent of CD4+ and CD8+ T lymphocytes, but required NK cells and IFNγ. Chimeric mice in which Batf3-dependent DCs uniformly lacked the capacity to produce IL12 had metastatic burdens similar to the Batf3-deficient mice, suggesting that Batf3+ DCs were the only cell type whose IL12 production was critical for controlling metastasis. We found that IL12-YFP reporter mice, whose lungs were injected with B16F10 melanoma, had increased numbers of IL12-expressing CD103+ DCs with enhanced CD86 expression. Bone-marrow-derived DCs from WT, but not Batf3-deficient, mice activated NK cells to produce IFNγ in an IL12-dependent manner and therapeutic injection of recombinant mouse IL12 decreased metastasis in both WT and Batf3-deficient mice. Analysis of TCGA datasets revealed an association between high expression of BATF3 and IRF8 and improved survival of breast cancer patients; BATF3 expression also significantly correlated with NK-cell receptor genes, IL12, and IFNG Collectively, our findings show that IL12 from CD103+ DCs is critical for NK cell-mediated control of tumor metastasis. Cancer Immunol Res; 5(12); 1098-108. ©2017 AACR.

The transcription factor Batf3 inhibits the differentiation of regulatory T cells in the periphery

Naive CD4 T cells activated by antigen-presenting cells (APCs) undergo terminal differentiation in the periphery. Multiple mechanisms determine their fates, that is, whether they differentiate into conventional T (Tconv) cells or regulatory T (Treg) cells. The key event during Treg generation is expression of the transcription factor Foxp3, which is the lineage-determining regulator for Treg differentiation and function. Here we show that the transcription factor Batf3 acts as a fate-decision factor with respect to Tconv versus Tregs by restraining Treg differentiation. Batf3 was preferentially expressed in effector CD4 T cells but not in Treg cells, and ectopic expression of Batf3 inhibited Foxp3 induction. Batf3-deficient CD4 T cells favorably differentiated into Treg cells in vitro and in colonic lamina propria. Batf3 KO mice also showed enhanced Treg function in gut-associated immune disease models (for example, ovalbumin tolerance and inflammatory bowel disease models). Batf3 bound to the CNS1 region of the Foxp3 locus and reduced expression of the gene. Thus, Batf3 is a transcriptional suppressor of Treg differentiation.

S1PR1 drives a feedforward signalling loop to regulate BATF3 and the transcriptional programme of Hodgkin lymphoma cells

The Hodgkin/Reed–Sternberg cells of classical Hodgkin lymphoma (HL) are characterised by the aberrant activation of multiple signalling pathways. Here we show that a subset of HL displays altered expression of sphingosine-1-phosphate (S1P) receptors (S1PR)s. S1P activates phosphatidylinositide 3-kinase (PI3-K) in these cells that is mediated by the increased expression of S1PR1 and the decreased expression of S1PR2. We also showed that genes regulated by the PI3-K signalling pathway in HL cell lines significantly overlap with the transcriptional programme of primary HRS cells. Genes upregulated by the PI3-K pathway included the basic leucine zipper transcription factor, ATF-like 3 (BATF3), which is normally associated with the development of dendritic cells. Immunohistochemistry confirmed that BATF3 was expressed in HRS cells of most HL cases. In contrast, in normal lymphoid tissues, BATF3 expression was confined to a small fraction of CD30-positive immunoblasts. Knockdown of BATF3 in HL cell lines revealed that BATF3 contributed to the transcriptional programme of primary HRS cells, including the upregulation of S1PR1. Our data suggest that disruption of this potentially oncogenic feedforward S1P signalling loop could provide novel therapeutic opportunities for patients with HL.

The differentiation of ROR-\u03b3t expressing iNKT17 cells is orchestrated by Runx1

iNKT cells are a unique lineage of T cells that recognize glycolipid presented by CD1d. In the thymus, they differentiate into iNKT1, iNKT2 and iNKT17 effector subsets, characterized by preferential expression of Tbet, Gata3 and ROR-γt and production of IFN-γ, IL-4 and IL-17, respectively. We demonstrate that the transcriptional regulator Runx1 is essential for the generation of ROR-γt expressing iNKT17 cells. PLZF-cre Runx1 cKO mice lack iNKT17 cells in the thymus, spleen and liver. Runx1-deficient iNKT cells have altered expression of several genes important for iNKT17 differentiation, including decreased expression of IL-7Rα, BATF and c-Maf and increased expression of Bcl11b and Lef1. However, reduction of Lef1 expression or introduction of an IL-7Rα transgene is not sufficient to correct the defect in iNKT17 differentiation, demonstrating that Runx1 is a key regulator of several genes required for iNKT17 differentiation. Loss of Runx1 leads to a severe decrease in iNKT cell numbers in the thymus, spleen and liver. The decrease in cell number is due to a combined decrease in proliferation at Stage 1 during thymic development and increased apoptosis. Thus, we describe a novel role of Runx1 in iNKT cell development and differentiation, particularly in orchestrating iNKT17 differentiation.