28th of May 2026 at 12:50 — 14:00
BioCity, Tykistökatu 6, 20520 Turku, Finland

Field of View research program presents a guest seminar:

Dr. Kari Vaahtomeri, University of Helsinki / Wihuri Research Institute

“Localized Exocytosis in Control of Guided Cell Migration”

Thursday, 28th of May, 13:00–14:00,  Auditorium Biologi, BioCity

Host: Guillaume Jacquemet (guillaume.jacquemet@abo.fi)

Image credits: Guillaume Jacquemet. Cell Migration Lab – Åbo Akademi University

 

We are pleased to welcome Dr. Kari Vaahtomeri from the University of Helsinki / Wihuri Research Institute, where he leads the Lymphatic Endothelial and Leukocyte Guidance group. Dr. Vaahtomeri is also affiliated with the new Centre of Excellence in Immune–Endothelial Interfaces (IMMENs). His recent work focuses on immune cell migration, lymphatic endothelial guidance cues, and mechanisms controlling leukocyte entry into lymphatic vessels.

Abstract:

Cell migration guidance is one of the most complex processes in cell biology. For example, development and immunity are critically dependent on timed and efficient arrival of cells to correct locations. In immunity, leukocyte’s function relies on continuous change of tissue compartments. In this context, one of the migration events that requires the highest accuracy is the leukocyte transmigration across the endothelium. Previous studies have shown that, for example, neutrophils prefer to transmigrate the blood endothelial multicellular vertices (i.e. the cell junction where multiple endothelial cells meet). These junctions are characterized by discontinuities in cell-cell junction proteins and increased ICAM expression, but it is not known how leukocytes are guided to these sites. To address this, we utilized chemokine CCL21-dependent antigen-presenting dendritic cell (DC) entry into the lymphatic system as a model of guided transmigration. By using in vivo, explant and primary cell co-culture assays of cell migration, together with advanced imaging methods, we have identified lymphatic endothelial multicellular vertices as sites of leukocyte entry into the lymphatics. Further, we show that the entry sites are determined by spatially confined guidance cue exocytosis, controlling dendritic cell migration to dermal lymphatic vessels. Altogether, our results exemplify how localized chemokine exocytosis is critical for cell migration guidance cue formation.

 

☕ Pulla, coffee & tea will be served at 12:50.

We look forward to seeing you at the seminar!