Gain-of-function IKBKB mutation causes human combined immune deficiency.

Abstract

Genetic mutations account for many devastating early onset immune deficiencies. In contrast, less severe and later onset immune diseases, including in patients with no prior family history, remain poorly understood. Whole exome sequencing in two cohorts of such patients identified a novel heterozygous de novo IKBKB missense mutation (c.607G>A) in two separate kindreds in whom probands presented with immune dysregulation, combined T and B cell deficiency, inflammation, and epithelial defects. IKBKB encodes IKK2, which activates NF-κB signaling. IKK2V203I results in enhanced NF-κB signaling, as well as T and B cell functional defects. IKK2V203 is a highly conserved residue, and to prove causation, we generated an accurate mouse model by introducing the precise orthologous codon change in Ikbkb using CRISPR/Cas9. Mice and humans carrying this missense mutation exhibit remarkably similar cellular and biochemical phenotypes. Accurate mouse models engineered by CRISPR/Cas9 can help characterize novel syndromes arising from de novo germline mutations and yield insight into pathogenesis.

• Authors: Chelisa Cardinez, Bahar Miraghazadeh, Kay Tanita, Elizabeth da Silva, Akihiro Hoshino, Satoshi Okada, Rochna Chand, Takaki Asano, Miyuki Tsumura, Kenichi Yoshida, Hidenori Ohnishi, Zenichiro Kato, Masahide Yamazaki, Yusuke Okuno, Satoru Miyano, Seiji Kojima, Seishi Ogawa, T Daniel Andrews, Matthew A Field, Gaetan Burgio, Tomohiro Morio, Carola G Vinuesa, Hirokazu Kanegane, Matthew C Cook
• Journal: The Journal of experimental medicine (J Exp Med) Vol. 215 Issue 11 Pg. 2715-2724 (11 05 2018) ISSN: 1540-9538 [Electronic] United States
• PMID: 30337470 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 Crown copyright. The government of Australia, Canada, or the UK ("the Crown") owns the copyright interests of authors who are government employees. The Crown Copyright is not transferable.

Chemical References

• I-kappa B Kinase
• IKBKB protein, human
• Ikbkb protein, mouse

Topics

• Amino Acid Substitution
• Animals
• Cohort Studies
• Female
• Gain of Function Mutation
• Heterozygote
• Humans
• I-kappa B Kinase (genetics, immunology)
• Immunologic Deficiency Syndromes (genetics, immunology)
• Male
• Mice
• Mice, Mutant Strains
• Whole Genome Sequencing