Selected Publications

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The Histone Methyltransferase Ezh2 Controls Mechanisms of Adaptive Resistance to Tumor Immunotherapy


Zingg D, Arenas-Ramirez N, Sahin D, Rosalia RA, Antunes AT, Haeusel J, Sommer L, Boyman O.
Abstract

Immunotherapy and particularly immune checkpoint inhibitors have resulted in remarkable clinical responses in patients with immunogenic tumors, although most cancers develop resistance to immunotherapy. The molecular mechanisms of tumor resistance to immunotherapy remain poorly understood. We now show that induction of the histone methyltransferase Ezh2 controls several tumor cell-intrinsic and extrinsic resistance mechanisms. Notably, T cell infiltration selectively correlated with high EZH2-PRC2 complex activity in human skin cutaneous melanoma. During anti-CTLA-4 or IL-2 immunotherapy in mice, intratumoral tumor necrosis factor-α (TNF-α) production and T cell accumulation resulted in increased Ezh2 expression in melanoma cells, which in turn silenced their own immunogenicity and antigen presentation. Ezh2 inactivation reversed this resistance and synergized with anti-CTLA-4 and IL-2 immunotherapy to suppress melanoma growth. These anti-tumor effects depended on intratumorally accumulating interferon-γ (IFN-γ)-producing PD-1low CD8+ T cells and PD-L1 downregulation on melanoma cells. Hence, Ezh2 serves as a molecular switch controlling melanoma escape during T cell-targeting immunotherapies.


Cell Rep. 2017 Jul 25;20(4):854-867.

DOI: 10.1016/j.celrep.2017.07.007

science2016

Improved cancer immunotherapy by a CD25-mimobody conferring selectivity to human interleukin-2


Arenas-Ramirez A, Zou C, Popp S, Zingg D, Brannetti B, Wirth E, Calzascia T, Kovarik J, Sommer L, Zenke G, Woytschak J, Regnier CH, Katopodis A, Boyman O.
Abstract

Interleukin-2 (IL-2) immunotherapy is an attractive approach in treating advanced cancer. However, by binding to its IL-2 receptor α (CD25) subunit, IL-2 exerts unwanted effects, including stimulation of immunosuppressive regulatory T cells (Tregs) and contribution to vascular leak syndrome. We used a rational approach to develop a monoclonal antibody to human IL-2, termed NARA1, which acts as a high-affinity CD25 mimic, thereby minimizing association of IL-2 with CD25. The structure of the IL-2–NARA1 complex revealed that NARA1 occupies the CD25 epitope of IL-2 and precisely overlaps with CD25. Association of NARA1 with IL-2 occurs with 10-fold higher affinity compared to CD25 and forms IL-2/NARA1 complexes, which, in vivo, preferentially stimulate CD8+ T cells while disfavoring CD25+ Tregs and improving the benefit–to–adverse effect ratio of IL-2. In two transplantable and one spontaneous metastatic melanoma model, IL-2/NARA1 complex immunotherapy resulted in efficient expansion of tumor-specific and polyclonal CD8+ T cells. These CD8+ T cells showed robust interferon-γ production and expressed low levels of exhaustion markers programmed cell death protein-1, lymphocyte activation gene-3, and T cell immunoglobulin and mucin domain-3. These effects resulted in potent anticancer immune responses and prolonged survival in the tumor models. Collectively, our data demonstrate that NARA1 acts as a CD25-mimobody that confers selectivity and increased potency to IL-2 and warrant further assessment of NARA1 as a therapeutic.


Science Translational Medicine. 2016 Nov 30: Vol. 8, Issue 367, pp. 367ra166.

DOI: 10.1126/scitranslmed.aag3187

immunity2016

Type 2 Interleukin-4 Receptor Signaling in Neutrophils Antagonizes Their Expansion and Migration during Infection and Inflammation


Janine W, Keller N, Krieg C, Impellizzieri D, Thompson RW, Wynn TA, Zinkernagel AS, Boyman O.
Abstract

Neutrophils are the first immune cells recruited to sites of inflammation and infection. However, patients with allergic disorders such as atopic dermatitis show a paucity of skin neutrophils and are prone to bacterial skin infections, suggesting that allergic inflammation curtails neutrophil responses. Here we have shown that the type 2 cell signature cytokine interleukin-4 (IL-4) hampers neutrophil expansion and migration by antagonizing granulocyte colony-stimulating factor (G-CSF) and chemokine receptor-mediated signals. Cutaneous bacterial infection in mice was exacerbated by IL-4 signaling and improved with IL-4 inhibition, each outcome inversely correlating with neutrophil migration to skin. Likewise, systemic bacterial infection was worsened by heightened IL-4 activity, with IL-4 restricting G-CSF-induced neutrophil expansion and migration to tissues by affecting CXCR2-CXCR4 chemokine signaling in neutrophils. These effects were dependent on IL-4 acting through type 2 IL-4 receptors on neutrophils. Thus, targeting IL-4 might be beneficial in neutropenic conditions with increased susceptibility to bacterial infections.


Immunity. 2016 July 19: Vol. 45, Issue 1, pp. 172–184.

DOI: 10.1016/j.immuni.2016.06.025

TREIMM OFC 36(12).indd

Interleukin-2: Biology, Design and Application


Arenas-Ramirez N, Woytschak J, Boyman O.
Abstract

IL-2 is crucial to T cell homeostasis, especially of CD4(+) T regulatory cells and memory CD8(+) cells, as evidenced by vigorous proliferation of these cells in vivo following injections of superagonist IL-2/anti-IL-2 antibody complexes. The mechanism of IL-2/anti-IL-2 antibody complexes is unknown owing to a lack of understanding of IL-2 homeostasis. We show that IL-2 receptor alpha (CD25) plays a crucial role in IL-2 homeostasis. Thus, prolongation of IL-2 half-life and blocking of CD25 using antibodies or CD25-deficient mice led in combination, but not alone, to vigorous IL-2-mediated T cell proliferation, similar to IL-2/anti-IL-2 antibody complexes. These data suggest an unpredicted role for CD25 in IL-2 homeostasis.


Trends Immunol. 2015 Nov 10. pii: S1471-4906(15)00248-3.

DOI: 10.1016/j.it.2015.10.003

jem2013

Epidermal IL-15Rα acts as an endogenous antagonist of psoriasiform inflammation in mouse and man


Grégory B, Gehrke S, Krieg C, Kolios A, Hafner J, Navarini AA, French LE, Boyman O.
Abstract

Stromal cells at epithelial surfaces contribute to innate immunity by sensing environmental danger signals and producing proinflammatory cytokines. However, the role of stromal cells in controlling local inflammation is unknown. We show that endogenous soluble IL-15 receptor α (IL-15Rα) derived from epidermal stroma, notably keratinocytes, protects against dendritic cell/IL-15-mediated, T cell-driven skin inflammation in vivo, and is relevant to human psoriasis. Selective lack of IL-15Rα on stromal epidermal cells exacerbated psoriasiform inflammation in animals. Epidermal IL-15Rα was shed by keratinocytes via proteolytic cleavage by matrix metalloproteinases upon stimulation with proinflammatory cytokines to counteract IL-15-induced proliferation of IL-17(+) αβ and γδ T cells and production of TNF, IL-23, IL-17, and IL-22 during skin inflammation. Notably, administration of soluble IL-15Rα was able to repress secretion of IL-1β, IL-6, and TNF by keratinocytes, dampen expansion of IL-17(+) αβ and γδ T cells in vivo, and prevent psoriasis in two mouse models, including human xenograft AGR mice. Serum levels of soluble IL-15Rα negatively correlated with disease severity, and levels rose upon successful treatment of psoriasis in patients. Thus, stressed epidermal stromal cells use soluble IL-15Rα to dampen chronic inflammatory skin disease.


JEM. 2013 Sep 9: Vol. 210 (107), 2105.

DOI: 10.1084/jem.20130291

nature2012

Exploiting a natural conformational switch to engineer an interleukin-2 ‘superkine’


Aron M. Levin, Bates DL, Ring AM, Krieg C, Lin JT, Su L, Moraga I, Raeber ME, Bowman GR, Novick P, Pande VS, Fathman CG, Boyman O & Garcia KC.
Abstract

The immunostimulatory cytokine interleukin-2 (IL-2) is a growth factor for a wide range of leukocytes, including T cells and natural killer (NK) cells1, 2, 3. Considerable effort has been invested in using IL-2 as a therapeutic agent for a variety of immune disorders ranging from AIDS to cancer. However, adverse effects have limited its use in the clinic. On activated T cells, IL-2 signals through a quaternary ‘high affinity’ receptor complex consisting of IL-2, IL-2Rα (termed CD25), IL-2Rβ and IL-2Rγ4, 5, 6, 7, 8. Naive T cells express only a low density of IL-2Rβ and IL-2Rγ, and are therefore relatively insensitive to IL-2, but acquire sensitivity after CD25 expression, which captures the cytokine and presents it to IL-2Rβ and IL-2Rγ. Here, using in vitro evolution, we eliminated the functional requirement of IL-2 for CD25 expression by engineering an IL-2 ‘superkine’ (also called super-2) with increased binding affinity for IL-2Rβ. Crystal structures of the IL-2 superkine in free and receptor-bound forms showed that the evolved mutations are principally in the core of the cytokine, and molecular dynamics simulations indicated that the evolved mutations stabilized IL-2, reducing the flexibility of a helix in the IL-2Rβ binding site, into an optimized receptor-binding conformation resembling that when bound to CD25. The evolved mutations in the IL-2 superkine recapitulated the functional role of CD25 by eliciting potent phosphorylation of STAT5 and vigorous proliferation of T cells irrespective of CD25 expression. Compared to IL-2, the IL-2 superkine induced superior expansion of cytotoxic T cells, leading to improved antitumour responses in vivo, and elicited proportionally less expansion of T regulatory cells and reduced pulmonary oedema. Collectively, we show that in vitro evolution has mimicked the functional role of CD25 in enhancing IL-2 potency and regulating target cell specificity, which has implications for immunotherapy.


Nature. 2012 April 26: Vol. 484, pp. 529–533.

DOI: 10.1038/nature10975

nature2012(b)

The role of interleukin-2 during homeostasis and activation of the immune system


Boyman O., Sprent J.
Abstract

Interleukin-2 (IL-2) signals influence various lymphocyte subsets during differentiation, immune responses and homeostasis. As discussed in this Review, stimulation with IL-2 is crucial for the maintenance of regulatory T (TReg) cells and for the differentiation of CD4+ T cells into defined effector T cell subsets following antigen-mediated activation. For CD8+ T cells, IL-2 signals optimize both effector T cell generation and differentiation into memory cells. IL-2 is presented in soluble form or bound to dendritic cells and the extracellular matrix. Use of IL-2 — either alone or in complex with particular neutralizing IL-2-specific antibodies — can amplify CD8+ T cell responses or induce the expansion of the TReg cell population, thus favouring either immune stimulation or suppression.


Nature Reviews Immunology. 2012 Mar: Vol. 12, pp. 180-190.

DOI: 10.1038/nri3156

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Improved IL-2 immunotherapy by selective stimulation of IL-2 receptors on lymphocytes and endothelial cells


Krieg C, Létourneau S, Pantaleo G, Boyman O.
Abstract

IL-2 immunotherapy is an attractive treatment option for certain metastatic cancers. However, administration of IL-2 to patients can lead, by ill-defined mechanisms, to toxic adverse effects including severe pulmonary edema. Here, we show that IL-2-induced pulmonary edema is caused by direct interaction of IL-2 with functional IL-2 receptors (IL-2R) on lung endothelial cells in vivo. Treatment of mice with high-dose IL-2 led to efficient expansion of effector immune cells expressing high levels of IL-2Rbetagamma, including CD8(+) T cells and natural killer cells, which resulted in a considerable antitumor response against s.c. and pulmonary B16 melanoma nodules. However, high-dose IL-2 treatment also affected immune cell lineage marker-negative CD31(+) pulmonary endothelial cells via binding to functional alphabetagamma IL-2Rs, expressed at low to intermediate levels on these cells, thus causing pulmonary edema. Notably, IL-2-mediated pulmonary edema was abrogated by a blocking antibody to IL-2Ralpha (CD25), genetic disruption of CD25, or the use of IL-2Rbetagamma-directed IL-2/anti-IL-2 antibody complexes, thereby interfering with IL-2 binding to IL-2Ralphabetagamma(+) pulmonary endothelial cells. Moreover, IL-2/anti-IL-2 antibody complexes led to vigorous activation of IL-2Rbetagamma(+) effector immune cells, which generated a dramatic antitumor response. Thus, IL-2/anti-IL-2 antibody complexes might improve current strategies of IL-2-based tumor immunotherapy.


Proc Natl Acad Sci U S A. 2010 Jun 29;107(26):11906-11.

DOI: 10.1073/pnas.1002569107

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IL-2/anti-IL-2 antibody complexes show strong biological activity by avoiding interaction with IL-2 receptor alpha subunit CD25


Létourneau S, van Leeuwen EM, Krieg C, Martin C, Pantaleo G, Sprent J, Surh CD, Boyman O
Abstract

IL-2 is crucial to T cell homeostasis, especially of CD4(+) T regulatory cells and memory CD8(+) cells, as evidenced by vigorous proliferation of these cells in vivo following injections of superagonist IL-2/anti-IL-2 antibody complexes. The mechanism of IL-2/anti-IL-2 antibody complexes is unknown owing to a lack of understanding of IL-2 homeostasis. We show that IL-2 receptor alpha (CD25) plays a crucial role in IL-2 homeostasis. Thus, prolongation of IL-2 half-life and blocking of CD25 using antibodies or CD25-deficient mice led in combination, but not alone, to vigorous IL-2-mediated T cell proliferation, similar to IL-2/anti-IL-2 antibody complexes. These data suggest an unpredicted role for CD25 in IL-2 homeostasis.


Proc Natl Acad Sci U S A. 2010 Feb 2;107(5):2171-6.

DOI: 10.1073/pnas.0909384107

Book Chapters

EncyclopediaofInflammatoryDiseases2015
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