GATA3-driven Th2 responses inhibit TGF-beta1-induced FOXP3 expression and the formation of regulatory T cells.

Transcription factors act in concert to induce lineage commitment towards Th1, Th2, or T regulatory (Treg) cells, and their counter-regulatory mechanisms were shown to be critical for polarization between Th1 and Th2 phenotypes. FOXP3 is an essential transcription factor for natural, thymus-derived (nTreg) and inducible Treg (iTreg) commitment; however, the mechanisms regulating its expression are as yet unknown. We describe a mechanism controlling iTreg polarization, which is overruled by the Th2 differentiation pathway. We demonstrated that interleukin 4 (IL-4) present at the time of T cell priming inhibits FOXP3. This inhibitory mechanism was also confirmed in Th2 cells and in T cells of transgenic mice overexpressing GATA-3 in T cells, which are shown to be deficient in transforming growth factor (TGF)-beta-mediated FOXP3 induction. This inhibition is mediated by direct binding of GATA3 to the FOXP3 promoter, which represses its transactivation process. Therefore, this study provides a new understanding of tolerance development, controlled by a type 2 immune response. IL-4 treatment in mice reduces iTreg cell frequency, highlighting that therapeutic approaches that target IL-4 or GATA3 might provide new preventive strategies facilitating tolerance induction particularly in Th2-mediated diseases, such as allergy

The global response to the COVID-19 pandemic: how have immunology societies contributed?

The COVID-19 pandemic is shining a spotlight on the field of immunology like never before. To appreciate the diverse ways in which immunologists have contributed, Nature Reviews Immunology invited the president of the International Union of Immunological Societies and the presidents of 15 other national immunology societies to discuss how they and their members responded following the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Erratum: Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome (J. Exp. Med. (2020) 217:6 Doi:10.1084/jem.20191804)

The authors regret that in the original version of Table S1, the column for patient 12 was mistakenly duplicated in the column for patient 8. The online Table S1 PDF has been corrected. The error appears only in PDFs downloaded before June 4, 2020

Dominant-negative mutations in human IL6ST underlie hyper-IgE syndrome

Autosomal dominant hyper-IgE syndrome (AD-HIES) is typically caused by dominant-negative (DN) STAT3 mutations. Patients suffer from cold staphylococcal lesions and mucocutaneous candidiasis, severe allergy, and skeletal abnormalities. We report 12 patients from 8 unrelated kindreds with AD-HIES due to DN IL6ST mutations. We identified seven different truncating mutations, one of which was recurrent. The mutant alleles encode GP130 receptors bearing the transmembrane domain but lacking both the recycling motif and all four STAT3-recruiting tyrosine residues. Upon overexpression, the mutant proteins accumulate at the cell surface and are loss of function and DN for cellular responses to IL-6, IL-11, LIF, and OSM. Moreover, the patients’ heterozygous leukocytes and fibroblasts respond poorly to IL-6 and IL-11. Consistently, patients with STAT3 and IL6ST mutations display infectious and allergic manifestations of IL-6R deficiency, and some of the skeletal abnormalities of IL-11R deficiency. DN STAT3 and IL6ST mutations thus appear to underlie clinical phenocopies through impairment of the IL-6 and IL-11 response pathways

Osteopontin has a crucial role in allergic airway disease through regulation of dendritic cell subsets

Osteopontin (Opn) is important for T helper type 1 (TH1) immunity and autoimmunity. However, the role of this cytokine in T H2-mediated allergic disease as well as its effects on primary versus secondary antigenic encounters remain unclear. Here we demonstrate that OPN is expressed in the lungs of asthmatic individuals and that Opn-s, the secreted form of Opn, exerts opposing effects on mouse TH2 effector responses and subsequent allergic airway disease: pro-inflammatory at primary systemic sensitization, and anti-inflammatory during secondary pulmonary antigenic challenge. These effects of Opn-s are mainly mediated by the regulation of TH2-suppressing plasmacytoid dendritic cells (DCs) during primary sensitization and TH2-promoting conventional DCs during secondary antigenic challenge. Therapeutic administration of recombinant Opn during pulmonary secondary antigenic challenge decreased established TH2 responses and protected mice from allergic disease. These effects on T H2 allergic responses suggest that Opn-s is an important therapeutic target and provide new insight into its role in immunity. © 2007 Nature Publishing Group

Consolidative dendritic cell-based immunotherapy elicits cytotoxicity against malignant mesothelioma.

Contains fulltext : 89130.pdf (publisher's version ) (Closed access)RATIONALE: We previously demonstrated that dendritic cell-based immunotherapy induced protective antitumor immunity with a prolonged survival rate in mice. However, the clinical relevance is still in question. To examine this, we designed a clinical trial using chemotherapy followed by antigen-pulsed dendritic cell vaccination in mesothelioma patients. OBJECTIVES: The aim of this study was to assess the safety and immunological response induced by the administration of tumor lysate-pulsed dendritic cells in patients with mesothelioma. METHODS: Ten patients with malignant pleural mesothelioma received three vaccinations of clinical-grade autologous dendritic cells intradermally and intravenously at 2-week intervals after chemotherapy. Each vaccine was composed of 50 x 10(6) mature dendritic cells pulsed with autologous tumor lysate and keyhole limpet hemocyanin (KLH) as surrogate marker. Delayed-type hypersensitivity activity to tumor antigens and KLH was assessed, both in vivo and in vitro. Peripheral blood mononuclear cells during the treatment were analyzed for immunological responses. MEASUREMENTS AND MAIN RESULTS: Administration of dendritic cells pulsed with autologous tumor lysate in patients with mesothelioma was safe with moderate fever as the only side effect. There were no grade 3 or 4 toxicities associated with the vaccines or any evidence of autoimmunity. Local accumulations of infiltrating T cells were found at the site of vaccination. The vaccinations induced distinct immunological responses to KLH, both in vitro and in vivo. Importantly, after three vaccinations, cytotoxic activity against autologous tumor cells was detected in a subgroup of patients. CONCLUSIONS: This study demonstrated that autologous tumor lysate-pulsed dendritic cell-based therapy is feasible, well-tolerated, and capable of inducing immunological response to tumor cells in mesothelioma patients. Clinical trial registered with www.clinicaltrials.gov (NCT00280982)

Directed antigen targeting in vivo identifies a role for CD103+ dendritic cells in both tolerogenic and immunogenic T-cell responses

The αE integrin chain CD103 identifies a subset of migratory dendritic cells (DCs) in the gut, lung, and skin. To gain further understanding of the function of CD103+ DCs in regulating adaptive immunity in vivo, we coupled ovalbumin (OVA) to the CD103 antibody M290 (M290.OVA). Intraperitoneal injection of M290.OVA induced OVA-specific CD8+ and CD4+ T-cell proliferation in lymph nodes (LNs) of wild-type but not CD103−/− mice, or in mice depleted of CD11c+ cells. In the absence of maturation stimuli, systemic antigen targeting to CD103+ DCs led to tolerance of CD8+ T cells, whereas coadministration of adjuvant induced cytotoxic T-lymphocyte (CTL) immunity and antibody production. Mucosal intratracheal application of M290.OVA also induced T-cell proliferation in mediastinal LNs, yet the functional outcome was tolerance that inhibited subsequent development of allergic airway inflammation and immunoglobulin E (IgE) responses to inhaled OVA. These findings identify antigen targeting to CD103+ DCs as a potential strategy to regulate immune responses in nonlymphoid mucosal ti