During her PhD studies, Kathrine Tejlgård Jensen investigated the function of protein Cluster of Differentiation 109 (CD109). CD109 is a GPI-anchored cell surface protein expressed on various human cell types, including keratinocytes, platelets, and activated T-cells. It functions as a modulator of transforming growth factor-β (TGF-β) signaling and is a member of the α2-macroglobulin protein superfamily. CD109 is upregulated in a range of cancers and inflammatory disorders, where its elevated expression is associated with disease progression. Kathrine Tejlgård Jensen studied how CD109 functions as a protease inhibitor through a trapping mechanism unique for the members of the α2-macroglobulin protein superfamily. She also developed CD109-specific nanobodies able to antagonize its inhibition of protease.

These findings contribute to the understanding of CD109’s function in both healthy and diseased tissue and provide a potential therapeutic strategy in which nanobodies block CD109’s function as a protease inhibitor and its re-localization.

The PhD study was completed at the Department of Molecular Biology and Genetics, Faculty of Natural Sciences, Aarhus University.

This summary was prepared by the PhD student.

Time: Thursday, 12 June 2025 at 13:00.
Place: Building 1871, room 120, Lecture Theatre Nucleus, Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, 8000 Aarhus C
Title of PhD thesis: CD109: A study of its function and structure, and development of CD109-antagonist nanobodies
Contact information: Kathrine Tejlgård Jensen, e-mail: kat@mbg.au.dk, tel.: +45 28 73 71 83
Members of the assessment committee:
Professor Michael Toft Overgaard, Department of Chemistry and Bioscience, Aalborg University, Denmark
Associate Professor, Philipp Arnold, Department of Functional and Clinical Anatomy, Friedrich-Alexander University, Germany
Professor Daan van Alten (chair), Department of Molecular Biology and Genetics, Aarhus University, Denmark
Main supervisor: Professor Jan J. Enghild, Department of Molecular Biology and Genetics, Aarhus University, Denmark
Co-supervisor: Assistant Professor Seandean Lykke Harwood, Department of Molecular Biology and Genetics, Aarhus Universite, Denmark
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Natural Sciences/GSNS, Ny Munkegade 120, building 1521, 8000 Aarhus C