9OD9 | pdb_00009od9

Structure of disulfide-stabilized IL-18 variant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 
    0.188 (Depositor), 0.189 (DCC) 
  • R-Value Work: 
    0.171 (Depositor), 0.171 (DCC) 
  • R-Value Observed: 
    0.171 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 9OD9

This is version 1.0 of the entry. See complete history

Literature

Engineered IL-18 variants with half-life extension and improved stability for cancer immunotherapy.

Bainbridge, T.W.Wang, L.Moskalenko, M.Herrera, R.Paluch, M.T.Sun, D.Tasneem, K.Saini, H.Sadek, M.Kwong, M.Kim, Y.M.Bhatt, J.M.Tam, C.Chan, P.P.F.Ovacik, A.M.Masureel, M.Zhao, Y.Sockolosky, J.T.Qu, Y.West, N.R.Bulutoglu, B.

(2025) J Immunother Cancer 13

  • DOI: https://doi.org/10.1136/jitc-2025-011789
  • Primary Citation Related Structures: 
    9OD7, 9OD9

  • PubMed Abstract: 

    The pro-inflammatory cytokine, interleukin-18 (IL-18), plays an instrumental role in bolstering anti-tumor immunity. However, the therapeutic application of IL-18 has been limited due to its susceptibility to neutralization by IL-18 binding protein (IL-18BP), short in vivo half-life, and unfavorable physicochemical properties. In order to overcome the poor drug-like properties of IL-18, we installed an artificial disulfide bond, removed the native, unpaired cysteines, and fused the stabilized cytokine to an IgG Fc domain. The stability, potency, pharmacokinetic and pharmacodynamic properties as well as efficacy of disulfide-stabilized IL-18 Fc-fusion (dsIL-18-Fc) were assessed via in vitro and in vivo studies. The stability and mammalian host cell production yields of dsIL-18-Fc were improved, compared to the wild-type (WT) cytokine, while maintaining its biological potency and interactions with IL-18 receptor α (IL-18Rα) and IL-18BP. Recombinant fusion of the cytokine to an IgG Fc domain provided extended half-life. Notably, despite maintaining sensitivity to IL-18BP, dsIL-18-Fc was effective at activating both T and natural killer (NK) cells, and elicited a strong anti-tumor response, either as a single agent, or in conjunction with anti-programmed cell death-ligand 1 (anti-PD-L1) therapy. We engineered IL-18 for reinforced stability, extended half-life, and improved manufacturability. The therapeutic benefit of dsIL-18-Fc, coupled with a more favorable manufacturability profile and enhanced drug-like properties, underscores the potential utility of this engineered cytokine in cancer immunotherapy.


  • Organizational Affiliation
    • Protein Sciences, Genentech Inc, South San Francisco, California, USA.

Macromolecule Content 

  • Total Structure Weight: 19.16 kDa 
  • Atom Count: 1,399 
  • Modeled Residue Count: 158 
  • Deposited Residue Count: 166 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Interleukin-18166Homo sapiensMutation(s): 0 
Gene Names: IL18IGIFIL1F4
UniProt & NIH Common Fund Data Resources
Find proteins for Q14116 (Homo sapiens)
Explore Q14116 
Go to UniProtKB:  Q14116
PHAROS:  Q14116
GTEx:  ENSG00000150782 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14116
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free:  0.188 (Depositor), 0.189 (DCC) 
  • R-Value Work:  0.171 (Depositor), 0.171 (DCC) 
  • R-Value Observed: 0.171 (Depositor) 
Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.821α = 90
b = 70.821β = 90
c = 88.66γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
autoPROCdata reduction
autoPROCdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2025-07-30
    Type: Initial release