The CD4(+) regulatory T (Treg) cell lineage, defined by FOXP3 expression, comprises thymus-derived (t)Treg cells and peripherally induced (p)Treg cells. As a model for Treg cells, studies employ... Show moreThe CD4(+) regulatory T (Treg) cell lineage, defined by FOXP3 expression, comprises thymus-derived (t)Treg cells and peripherally induced (p)Treg cells. As a model for Treg cells, studies employ TGF-beta-induced (i)Treg cells generated from CD4(+) conventional T (Tconv) cells in vitro. Here, we describe how human iTreg cells relate to human blood-derived tTreg and Tconv cells according to proteomic analysis. Each of these cell populations had a unique protein expression pattern. iTreg cells had very limited overlap in protein expression with tTreg cells, regardless of cell activation status and instead shared signaling and metabolic proteins with Tconv cells. tTreg cells had a uniquely modest response to CD3/CD28-mediated stimulation. As a benchmark, we used a previously defined proteomic signature that discerns ex vivo naive and effector Treg cells from Tconv cells and includes conserved Treg cell properties. iTreg cells largely lacked this Treg cell core signature and highly expressed e.g. STAT4 and NFATC2, which may contribute to inflammatory responses. We also used a proteomic signature that distinguishes ex vivo effector Treg cells from Tconv cells and naive Treg cells. iTreg cells contained part of this effector Treg cell signature, suggesting acquisition of pTreg cell features. In conclusion, iTreg cells are distinct from tTreg cells and share limited features with ex vivo Treg cells at the proteomic level. Show less
Mensink, M.; Tran, T.N.M.; Zaal, E.A.; Schrama, E.; Berkers, C.R.; Borst, J.; Kivit, S. de 2022
CD4(+) conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases... Show moreCD4(+) conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases. The opposing activities of Tconvs and Tregs depend on the stage of the immune response and their environment, with an orchestrating role for cytokine- and costimulatory receptors. Nutrient availability also impacts T-cell functionality via metabolic and biosynthetic processes that are largely unexplored. Many data argue that costimulation by Tumor Necrosis Factor Receptor 2 (TNFR2) favors support of Treg over Tconv responses and therefore TNFR2 is a key clinical target. Here, we review the pertinent literature on this topic and highlight the newly identified role of TNFR2 as a metabolic regulator for thymus-derived (t)Tregs. We present novel transcriptomic and metabolomic data that show the differential impact of TNFR2 on Tconv and tTreg gene expression and reveal distinct metabolic impact on both cell types. Show less
Mensink, M.; Tran, T.N.M.; Zaal, E.A.; Schrama, E.; Berkers, C.R.; Borst, J.; Kivit, S. de 2022
CD4+ conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases.... Show moreCD4+ conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases. The opposing activities of Tconvs and Tregs depend on the stage of the immune response and their environment, with an orchestrating role for cytokine- and costimulatory receptors. Nutrient availability also impacts T-cell functionality via metabolic and biosynthetic processes that are largely unexplored. Many data argue that costimulation by Tumor Necrosis Factor Receptor 2 (TNFR2) favors support of Treg over Tconv responses and therefore TNFR2 is a key clinical target. Here, we review the pertinent literature on this topic and highlight the newly identified role of TNFR2 as a metabolic regulator for thymus-derived (t)Tregs. We present novel transcriptomic and metabolomic data that show the differential impact of TNFR2 on Tconv and tTreg gene expression and reveal distinct metabolic impact on both cell types. Show less
Mensink, M.; Tran, T.N.M.; Zaal, E.A.; Schrama, E.; Berkers, C.R.; Borst, J.; Kivit, S. de 2022
CD4(+) conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases... Show moreCD4(+) conventional T cells (Tconvs) mediate adaptive immune responses, whereas regulatory T cells (Tregs) suppress those responses to safeguard the body from autoimmunity and inflammatory diseases. The opposing activities of Tconvs and Tregs depend on the stage of the immune response and their environment, with an orchestrating role for cytokine- and costimulatory receptors. Nutrient availability also impacts T-cell functionality via metabolic and biosynthetic processes that are largely unexplored. Many data argue that costimulation by Tumor Necrosis Factor Receptor 2 (TNFR2) favors support of Treg over Tconv responses and therefore TNFR2 is a key clinical target. Here, we review the pertinent literature on this topic and highlight the newly identified role of TNFR2 as a metabolic regulator for thymus-derived (t)Tregs. We present novel transcriptomic and metabolomic data that show the differential impact of TNFR2 on Tconv and tTreg gene expression and reveal distinct metabolic impact on both cell types. Show less
Autotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and... Show moreAutotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis via LPAR1 and T cell motility via LPAR2, yet its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes (TILs) and circulating CD8(+) T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T cell repulsion predominantly involves G alpha(12/13)-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8(+) T cells and thereby impairs tumor regression. Moreover, single-cell data from melanoma tumors are consistent with intratumoral ATX acting as a T cell repellent. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8(+) T cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities. Show less
Kivit, S. de; Mensink, M.; Hoekstra, A.T.; Berlin, I.; Derks, R.J.E.; Both, D.; ... ; Borst, J. 2020
Following activation, conventional T (T-conv) cells undergo an mTOR-driven glycolytic switch. Regulatory T (T-reg) cells reportedly repress the mTOR pathway and avoid glycolysis. However, here we... Show moreFollowing activation, conventional T (T-conv) cells undergo an mTOR-driven glycolytic switch. Regulatory T (T-reg) cells reportedly repress the mTOR pathway and avoid glycolysis. However, here we demonstrate that human thymus-derived T-reg (tT(reg)) cells can become glycolytic in response to tumour necrosis factor receptor 2 (TNFR2) costimulation. This costimulus increases proliferation and induces a glycolytic switch in CD3-activated tT(reg) cells, but not in T-conv cells. Glycolysis in CD3-TNFR2-activated tT(reg) cells is driven by PI3-kinase-mTOR signalling and supports tT(reg) cell identity and suppressive function. In contrast to glycolytic T-conv cells, glycolytic tT(reg) cells do not show net lactate secretion and shuttle glucose-derived carbon into the tricarboxylic acid cycle. Ex vivo characterization of blood-derived TNFR2(hi)CD4(+)CD25(hi)CD127(lo) effector T cells, which were FOXP3(+)IKZF2(+), revealed an increase in glucose consumption and intracellular lactate levels, thus identifying them as glycolytic tT(reg) cells. Our study links TNFR2 costimulation in human tT(reg) cells to metabolic remodelling, providing an additional avenue for drug targeting. Show less
Opstelten, R.; Kivit, S. de; Slot, M.C.; Biggelaar, M. van den; Iwaszkiewicz-Grzes, D.; Gliwinski, M.; ... ; Amsen, D. 2020
FOXP3-expressing regulatory T (Treg) cells safeguard immunological tolerance. Treg cells can be generated during thymic development (called thymic Treg [tTreg] cells) or derived from mature... Show moreFOXP3-expressing regulatory T (Treg) cells safeguard immunological tolerance. Treg cells can be generated during thymic development (called thymic Treg [tTreg] cells) or derived from mature conventional CD4(+) T cells that underwent TGF-beta- mediated conversion in the periphery (called peripheral Treg [pTreg] cells). Murine studies have shown that tTreg cells exhibit strong lineage fidelity, whereas pTreg cells can revert into conventional CD4(+) T cells. Their stronger lineage commitment makes tTreg cells the safest cells to use in adoptive cell therapy, increasingly used to treat autoimmune and inflammatory disorders. Markers to distinguish human tTreg cells from pTreg cells have, however, not been found. Based on combined proteomic and transcriptomic approaches, we report that the Ig superfamily protein GPA33 is expressed on a subset of human Treg cells. GPA33 is acquired late during tTreg cell development but is not expressed on TGF-beta-induced Treg cells. GPA33 identifies Treg cells in human blood that lack the ability to produce effector cytokines (IL-2, IFN-gamma, IL-17), regardless of differentiation stage. GPA33(high) Treg cells universally express the transcription factor Helios that preferentially marks tTreg cells and can robustly and stably be expanded in vitro even without rapamycin. Expanded GPA33(high) Treg cells are suppressive, unable to produce proinflammatory cytokines, and exhibit the epigenetic modifications of the FOXP3 gene enhancer CNS2, necessary for indelible expression of this critical transcription factor. Our findings thus suggest that GPA33 identifies human tTreg cells and provide a strategy to isolate such cells for safer and more efficacious adoptive cell therapy. Show less
Within lymph nodes (LNs), T follicular helper (T-FH) cells help B cells to produce antibodies, which can either be protective or autoreactive. Here, we demonstrate that murine LN stromal cells ... Show moreWithin lymph nodes (LNs), T follicular helper (T-FH) cells help B cells to produce antibodies, which can either be protective or autoreactive. Here, we demonstrate that murine LN stromal cells (LNSCs) suppress the formation of autoreactive T-FH cells in an antigen-specific manner, thereby significantly reducing germinal center B cell responses directed against the same self-antigen. Mechanistically, LNSCs express and present self-antigens in major histocompatibility complex (MHC) class II, leading to the conversion of naive CD4(+) T cells into T regulatory (T-REG) cells in an interleukin-2 (IL-2)-dependent manner. Upon blockade of TREG cells, using neutralizing IL-2 antibodies, autoreactive T-FH cells are allowed to develop. We conclude that the continuous presentation of self-antigens by LNSCs is critical to generate antigen-specific TREG cells, thereby repressing the formation of T-FH cells and germinal center B cell responses. Our findings uncover the ability of LNSCs to suppress the early activation of autoreactive immune cells and maintain peripheral tolerance. Show less
