- EMDB-66420: IL-33 and Itepekimab fab and Tozorakimab fab ternary complex structure -
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基本情報
登録情報
データベース: EMDB / ID: EMD-66420
タイトル
IL-33 and Itepekimab fab and Tozorakimab fab ternary complex structure
マップデータ
試料
複合体: IL-33 and Itepekimab fab and Tozorakimab fab ternary complex structure
タンパク質・ペプチド: Interleukin-33 (109-270)
タンパク質・ペプチド: Tozorakimab-L chain
タンパク質・ペプチド: Tozorakimab-H chain
タンパク質・ペプチド: Itepekimab-K chain
タンパク質・ペプチド: Itepekimab-H chain
キーワード
IL33 / antibody Itepekimab fab / antibody Tozorakimab fab / CYTOKINE/IMMUNE SYSTEM / CYTOKINE-IMMUNE SYSTEM complex
機能・相同性
機能・相同性情報
interleukin-33 receptor binding / negative regulation of macrophage proliferation / positive regulation of cellular defense response / Interleukin-33 signaling / positive regulation of MHC class I biosynthetic process / negative regulation of immunoglobulin production / microglial cell activation involved in immune response / negative regulation of T-helper 1 type immune response / negative regulation of leukocyte migration / negative regulation of inflammatory response to wounding ...interleukin-33 receptor binding / negative regulation of macrophage proliferation / positive regulation of cellular defense response / Interleukin-33 signaling / positive regulation of MHC class I biosynthetic process / negative regulation of immunoglobulin production / microglial cell activation involved in immune response / negative regulation of T-helper 1 type immune response / negative regulation of leukocyte migration / negative regulation of inflammatory response to wounding / antibacterial innate immune response / positive regulation of glycoprotein biosynthetic process / microglial cell proliferation / interleukin-33-mediated signaling pathway / positive regulation of type 2 immune response / positive regulation of interleukin-5 production / positive regulation of interleukin-13 production / positive regulation of MHC class II biosynthetic process / positive regulation of macrophage activation / type 2 immune response / positive regulation of neuroinflammatory response / positive regulation of immunoglobulin production / positive regulation of interleukin-4 production / negative regulation of type II interferon production / macrophage differentiation / transport vesicle / extrinsic apoptotic signaling pathway / positive regulation of chemokine production / cytokine activity / positive regulation of cytokine production / positive regulation of interleukin-6 production / response to wounding / positive regulation of tumor necrosis factor production / protein import into nucleus / positive regulation of inflammatory response / PIP3 activates AKT signaling / positive regulation of proteasomal ubiquitin-dependent protein catabolic process / chromosome / PI5P, PP2A and IER3 Regulate PI3K/AKT Signaling / gene expression / defense response to virus / Ub-specific processing proteases / positive regulation of gene expression / negative regulation of transcription by RNA polymerase II / positive regulation of transcription by RNA polymerase II / : / extracellular region / nucleoplasm / nucleus / cytoplasm 類似検索 - 分子機能
ジャーナル: MAbs / 年: 2026 タイトル: Structures of clinical antibodies bound to IL-33 uncover two distinct epitopes underlying differential efficacy. 著者: Jing Chen / Yue Wang / Xinquan Wang / 要旨: Interleukin-33 (IL-33), an alarmin cytokine of the IL-1 family, drives type 2 inflammation through signaling via the ST2 and IL-1RAcP receptors, making it a critical therapeutic target for ...Interleukin-33 (IL-33), an alarmin cytokine of the IL-1 family, drives type 2 inflammation through signaling via the ST2 and IL-1RAcP receptors, making it a critical therapeutic target for inflammatory diseases such as asthma and chronic obstructive pulmonary disease. Current therapeutic strategies have primarily focused on antibodies that target IL-33 or ST2 to disrupt their specific interaction. However, the structural mechanisms underlying antibody-mediated neutralization of IL-33 remain poorly understood. Here, we report the structures of three antibodies in clinical trial - etokimab, itepekimab, and tozorakimab - complexed with IL-33, determined by X-ray crystallography and cryo-electron microscopy. Structural analysis reveals two distinct neutralizing epitopes on IL-33, termed Epitope 1 at IL-33/ST2 binding Site 1 and Epitope 2 at IL-33/ST2 binding Site 2. Tozorakimab, which targets Epitope 1, completely blocks ST2 engagement by sterically occluding the ST2 D1-D2 domain-binding interface. In contrast, etokimab and itepekimab, which recognize Epitope 2, interfere with IL-33 recognition of the ST2 D3 domain and thereby only partially inhibit ST2 binding. These structural and biochemical findings provide a molecular explanation for the differential efficacy of the three antibodies in inhibiting IL-33 signaling in cellular assays. Collectively, our results provide valuable insights into the molecular determinants of efficacy for existing IL-33 therapeutics and offer a structural framework for the rational design of next-generation IL-33 targeted inhibitors.