Our immune system protects us against disease and cancer. Dendritic cells are immune cells that must travel through the body to set off a defensive response. This thesis shows that a protein called galectin-9 is essential for this movement: without it, these cells can no longer contract their rear end and become unable to migrate properly.
The thesis also reveals how cancer cells evade the immune system. Tumor cells carry a protein, PD-L1, on their surface that switches off immune attacks. We discovered that another protein, TSPAN4, acts as a brake on PD-L1, lowering its levels in melanoma. We also found that PD-L1 is not spread evenly but clustered into tiny groups, and that several factors - including the cell's internal scaffold - control this fine-scale arrangement.
Together, these findings advance our understanding of immune cell movement and cancer's escape, helping to improve immunotherapies.
Guust Franken (1996) graduated from his study Life Sciences at Utrecht University in 2019. In 2021 he started his PhD research as part of the Experimental Immunology Group at the Department of Medical BioSciences of Radboud university medical center.