Speaker: Professor Pablo Saez, Cell Communication and Migration Laboratory, UKE, Hamburg

Title: Danger signal control of leukocyte migration
Time: 24 September 2026, 14:00-15:00
Location: Lauren 1, Medisiina D

Talk Abstract:

Danger signals are released by immune and non-immune cells, and trigger leukocyte motility at different levels. Conventional danger signals include pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide (LPS), and damage-associated molecular patterns (DAMPs), such as adenosine triphosphate (ATP), both of which are known to regulate immune cell migration. These and other migratory stimuli converge in triggering calcium (Ca2+) signals that subsequently allows reorganization of the cytoskeleton, actomyosin contractility, and gene expression. However, the crosstalk between different danger signals and the temporal kinetics of their effect are not fully understood. To study this, we used murinemodels of leukocytes (DCs, macrophages, T cells, and B cells), and combine microfluidics with live-cell to monitor cellular behaviour. We found that ATP and LPS act in a kinetic- and cell-specific fashion. In addition, we found that specific ATP receptors have opposite contributions in different leukocytes. The long-lasting Ca2+-independent activation of proteins, such as CaMKII, might contribute to persistent changes in the migratory behaviour, and -over time- changes in the expression profile of motile cells.

About the speaker:

Pablo J. Sáez is a cell biologist from Chile where he did most of his training until the PhD working in cell communication and inflammation in the lab at the Juan Sáez lab (Catholic University). Then, he did a short transition in the same university, in the lab of Marcelo Farías working in organelles, in particular in obesity-induced ER stress. Then, he came to Europe as a postdoc to work in leukocyte migration and organelle polarity in the lab of Ana-María Lennon at the Institut Curie in Paris. From there he move to the lab of Matthieu Piel at IPGG-Curie (in the group of Pablo Vargas) to continue his work in leukocyte migration and microfluidics. In 2020 he started his own group as a Full Professor at the UKE in Hamburg, and since 2022 he leads a HFSP grant team (in collaboration with Yamuna Krishnan and Nir Gov) dedicated to understand directional decision-making. He also has a keen interest in promoting diversity, mentoring, scientific communication, and SciArt, with participations as an eLife ambassador, and member of scientific advisory board of Focal Plane.