Signal transducer and activator of transcription 3 (STAT3) triggered production of Th-17 cytokines mediates protective immunity against fungi. Mutations affecting the STAT3/interleukin 17 (IL-17) pathway cause selective susceptibility to fungal (Candida) infections, a hallmark of chronic mucocutaneous candidiasis (CMC). In patients with autosomal dominant CMC, we and others previously reported defective Th17 responses and underlying gain-of-function (GOF) STAT1 mutations, but how this affects STAT3 function leading to decreased IL-17 is unclear. We also assessed how GOF-STAT1 mutations affect STAT3 activation, DNA binding, gene expression, cytokine production, and epigenetic modifications. We excluded impaired STAT3 phosphorylation, nuclear translocation, and sequestration of STAT3 into STAT1/STAT3 heterodimers and confirm significantly reduced transcription of STAT3-inducible genes (RORC/IL-17/IL-22/IL-10/c-Fos/SOCS3/cMyc) as likely underlying mechanism. STAT binding to the high affinity sis-inducible element was intact but binding to an endogenous STAT3 DNA target was impaired. Reduced STAT3-dependent gene transcription was reversed by inhibiting STAT1 activation with fludarabine or enhancing histone, but not STAT1 or STAT3 acetylation with histone deacetylase (HDAC) inhibitors trichostatin A or ITF2357. Silencing HDAC1, HDAC2, and HDAC3 indicated a role for HDAC1 and 2. Reduced STAT3-dependent gene transcription underlies low Th-17 responses in GOF-STAT1 CMC, which can be reversed by inhibiting acetylation, offering novel targets for future therapies.Correspondence: Dr. Desa Lilic e-mail: desa.lilic@ncl.ac.uk * Both authors contributed equally to this work.C 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.eji-journal.eu Eur. J. Immunol. 2015. 45: 2834-2846 Immunity to infection 2835 Keywords: Chronic mucocutaneous candidiasis (CMC) HDAC inhibitors IL-17 STAT1 gain-of-function mutation STAT3 STAT1 inhibitorsAdditional supporting information may be found in the online version of this article at the publisher's web-site IntroductionPatients with chronic mucocutaneous candidiasis (CMC) present with recurrent or persistent infections of the skin, nails, and mucosal membranes with the fungus Candida [1]. Candida is an opportunistic yeast that does not cause disease in healthy individuals despite inhabiting bodily surfaces as it is controlled by immune mechanisms, specifically Th-17 cells and cytokines produced by them [2]. Mucosal infections with Candida species indicate an underlying T-cell deficiency, which is most often secondary to immunosuppressive and/or chemotherapy, antibiotics, biological therapies, HIV, or other permissive circumstances. However, in rare patients, these infections present as a severe syndrome coined CMC, a primary immune deficiency in which the underlying cause is a genetic mutation affecting immune pathways essential for fungal protection [3]. Research in primary immune deficiency patients with isolated CMC has documented the crucial role of the signal transducer and activator of tra...

2020) Preclinical evaluation of an affinity-enhanced MAGE-A4-specific T-cell receptor for adoptive T-cell therapy, OncoImmunology, 9:1, 1682381, ABSTRACT A substantial obstacle to the success of adoptive T cell-based cancer immunotherapy is the sub-optimal affinity of T-cell receptors (TCRs) for most tumor antigens. Genetically engineered TCRs that have enhanced affinity for specific tumor peptide-MHC complexes may overcome this barrier. However, this enhancement risks increasing weak TCR cross-reactivity to other antigens expressed by normal tissues, potentially leading to clinical toxicities. To reduce the risk of such adverse clinical outcomes, we have developed an extensive preclinical testing strategy, involving potency testing using 2D and 3D human cell cultures and primary tumor material, and safety testing using human primary cell and cell-line crossreactivity screening and molecular analysis to predict peptides recognized by the affinity-enhanced TCR. Here, we describe this strategy using a developmental T-cell therapy, ADP-A2M4, which recognizes the HLA-A2-restricted MAGE-A4 peptide GVYDGREHTV. ADP-A2M4 demonstrated potent anti-tumor activity in the absence of major off-target cross-reactivity against a range of human primary cells and cell lines. Identification and characterization of peptides recognized by the affinity-enhanced TCR also revealed no cross-reactivity. These studies demonstrated that this TCR is highly potent and without major safety concerns, and as a result, this TCR is now being investigated in two clinical trials (NCT03132922, NCT04044768). ARTICLE HISTORY

Adoptive T cell therapy with T cells expressing affinity-enhanced TCRs has shown promising results in phase 1/2 clinical trials for solid and hematological tumors. However, depth and durability of responses to adoptive T cell therapy can suffer from an inhibitory tumor microenvironment. A common immune-suppressive agent is TGF-β, which is secreted by tumor cells and cells recruited to the tumor. We investigated whether human T cells could be engineered to be resistant to inhibition by TGF-β. Truncating the intracellular signaling domain from TGF-β receptor (TGFβR) II produces a dominant-negative receptor (dnTGFβRII) that dimerizes with endogenous TGFβRI to form a receptor that can bind TGF-β but cannot signal. We previously generated specific peptide enhanced affinity receptor TCRs recognizing the HLA-A*02–restricted peptides New York esophageal squamous cell carcinoma 1 (NY-ESO-1)157–165/l-Ag family member-1A (TCR: GSK3377794, formerly NY-ESO-1c259) and melanoma Ag gene A10254–262 (TCR: ADP-A2M10, formerly melanoma Ag gene A10c796). In this article, we show that exogenous TGF-β inhibited in vitro proliferation and effector functions of human T cells expressing these first-generation high-affinity TCRs, whereas inhibition was reduced or abolished in the case of second-generation TCRs coexpressed with dnTGFβRII (e.g., GSK3845097). TGF-β isoforms and a panel of TGF-β–associated genes are overexpressed in a range of cancer indications in which NY-ESO-1 is commonly expressed, particularly in synovial sarcoma. As an example, immunohistochemistry/RNAscope identified TGF-β–positive cells close to T cells in tumor nests and stroma, which had low frequencies of cells expressing IFN-γ in a non–small cell lung cancer setting. Coexpression of dnTGFβRII may therefore improve the efficacy of TCR-transduced T cells.

Loss-of-function mutations of the Autoimmune Regulator (AIRE) gene results in organ-specific autoimmunity and disease Autoimmune Polyendocrinopathy type 1 (APS1)/Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED). The AIRE protein is crucial in the induction of central tolerance, promoting ectopic expression of tissue-specific antigens in medullary thymic epithelial cells and enabling removal of self-reactive T-cells. AIRE expression has recently been detected in myeloid dendritic cells (DC), suggesting AIRE may have a significant role in peripheral tolerance. DC stimulation of T-cells is critical in determining the initiation or lack of an immune response, depending on the pattern of costimulation and cytokine production by DCs, defining immunogenic/inflammatory (inflDC) and tolerogenic (tolDC) DC. In AIRE-deficient patients and healthy controls, we validated the role of AIRE in the generation and function of monocyte-derived inflDC and tolDCs by determining mRNA and protein expression of AIRE and comparing activation markers (HLA-DR/DP/DQ,CD83,CD86,CD274(PDL-1),TLR-2), cytokine production (IL-12p70,IL-10,IL-6,TNF-α,IFN-γ) and T-cell stimulatory capacity (mixed lymphocyte reaction) of AIRE+ and AIRE- DCs. We show for the first time that: (1) tolDCs from healthy individuals express AIRE; (2) AIRE expression is not significantly higher in tolDC compared to inflDC; (3) tolDC can be generated from APECED patient monocytes and (4) tolDCs lacking AIRE retain the same phenotype and reduced T-cell stimulatory function. Our findings suggest that AIRE does not have a role in the induction and function of monocyte-derived tolerogenic DC in humans, but these findings do not exclude a role for AIRE in peripheral tolerance mediated by other cell types.

cells in peripheral blood mononuclear cells (PBMCs) treated with gastro-sphere conditioned medium in comparison with non-gastro-sphere conditioned medium. It was also demonstrated that T cell expansion was not significantly decreased in gastro-sphere conditioned medium treatment compared with the parental (non-gastrospheres) and control group. Conclusions: We concluded that gastro-sphere-soluble factors increase the percentage of Treg and Th17 cells more than its parental soluble factors. This suggested the possible existence of differentiation factors such as key cytokines among tumor cell secretions, which contribute to T cell differentiation. While it has been shown that gastro-sphere secretions can be possibly more immunomodulator than its parental cell secretions and lead to limited T cell expansion. Legal entity responsible for the study: