Masking the immunotoxicity of interleukin-12 by fusing it with a domain of its receptor via a tumour-protease-cleavable linker

Nat Biomed Eng. 2022 Jul;6(7):819-829. doi: 10.1038/s41551-022-00888-0. Epub 2022 May 9.


Immune-checkpoint inhibitors have shown modest efficacy against immunologically 'cold' tumours. Interleukin-12 (IL-12)-a cytokine that promotes the recruitment of immune cells into tumours as well as immune cell activation, also in cold tumours-can cause severe immune-related adverse events in patients. Here, by exploiting the preferential overexpression of proteases in tumours, we show that fusing a domain of the IL-12 receptor to IL-12 via a linker cleavable by tumour-associated proteases largely restricts the pro-inflammatory effects of IL-12 to tumour sites. In mouse models of subcutaneous adenocarcinoma and orthotopic melanoma, masked IL-12 delivered intravenously did not cause systemic IL-12 signalling and eliminated systemic immune-related adverse events, led to potent therapeutic effects via the remodelling of the immune-suppressive microenvironment, and rendered cold tumours responsive to immune-checkpoint inhibition. We also show that masked IL-12 is activated in tumour lysates from patients. Protease-sensitive masking of potent yet toxic cytokines may facilitate their clinical translation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytokines
  • Immunotherapy
  • Interleukin-12* / pharmacology
  • Melanoma*
  • Mice
  • Peptide Hydrolases
  • Tumor Microenvironment


  • Cytokines
  • Interleukin-12
  • Peptide Hydrolases