Generation and characterization of antagonistic anti-human interleukin (IL)-18 monoclonal antibodies with high affinity: Two types of monoclonal antibodies against full-length IL-18 and the neoepitope of inflammatory caspase-cleaved active IL-18

Arch Biochem Biophys. 2019 Mar 15;663:71-82. doi: 10.1016/j.abb.2019.01.001. Epub 2019 Jan 4.

Abstract

Interleukin-18 (IL-18) is a pro-inflammatory cytokine that evokes both innate and acquired immune responses. IL-18 is initially synthesized as an inactive precursor and the cleavage for processing into a mature, active molecule is mediated by pro-inflammatory caspases following the activation of inflammasomes. Two types of monoclonal antibodies were raised: anti-IL-1863-68 antibodies which recognize full-length1-193 and cleaved IL-18; and anti-IL-18 neoepitope antibodies which specifically recognize the new N-terminal 37YFGKLESK44 of IL-18 cleaved by pro-inflammatory caspase-1/4. These mAbs were suitable for Western blotting, capillary Western immunoassay (WES), immunofluorescence, immunoprecipitation, and function-blocking assays. WES analysis of these mAbs allowed visualization of the IL-18 bands and provided a molecular weight corresponding to the pro-inflammatory caspase-1/4 cleaved, active form IL-1837-193, and not to the inactive precursor IL-18, in the serum of patients with adult-onset Still's disease (6/14, 42%) and hemophagocytic activation syndrome (2/6, 33%). These monoclonal antibodies will be very useful in IL-18 and inflammasome biology and for diagnostic and therapeutic strategies for inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / biosynthesis*
  • Antibodies, Monoclonal / immunology*
  • Antibody Affinity
  • Caspases / metabolism*
  • Cell Line, Tumor
  • HEK293 Cells
  • Humans
  • Inflammation Mediators / immunology*
  • Inflammation Mediators / metabolism
  • Interferon-gamma / metabolism
  • Interleukin-18 / immunology*
  • Interleukin-18 / metabolism
  • Proteolysis

Substances

  • Antibodies, Monoclonal
  • IL18 protein, human
  • Inflammation Mediators
  • Interleukin-18
  • Interferon-gamma
  • Caspases