Immobilized chemokine fields and soluble chemokine gradients cooperatively shape migration patterns of dendritic cells Kathrin Schumann, Tim Lämmermann,Markus Bruckner,Daniel F. Legler, Julien Polleux, Joachim P. Spatz,Gerold Schuler, Reinhold Förster, Manfred B. Lutz, Lydia Sorokin, and Michael Sixt Marius Döring ZIB Class of 2009 paper presentation

Introduction Chemokines: chemotactic cytokines – Small 8-10 kDa – classification according to positioning of 4 cysteine residues – signal via GPCR central orchestrators of hematopoetic system – Homing & positioning of lymphocytes in secondary lymphoid organs – Integrin activation – Polarization of actomyosin cytoskeleton

Introduction Cell movement on a surface: Haptokinesis vs haptotaxis adhesion independent: chemokinesis va chemotaxis ChemotaxisHaptokinesis Haptotaxis biased by chemotactic gradient

Model system: Migration of DC depentent on CCR7 and its ligands CCL19/21 CCL19: mostly soluble due to truncated N-terminus CCL21: binds to heperansulfate Adopted from Rot et. al 2008

Results LPS matured DC on unfixed cryosection of inguinal LN DCs mirgate on LN into the T cell area along the interfollicular region

Results DCs mirgate on LN in a CCR7 & CCR7 ligand dependent manner along a soluble gradient

Results Immobilized CCL21 triggers: 1)rapid spreading 2)random migration 3)release of soluble factor to attract other DCs

Results DCs generate a truncated CCL21 upon encouter of CCL21 by cleavage from the C terminus

Results Haptokinesis (spreading, polarization & migration) of DCs is induced by interaction of CCR7 and immobilized ß2 integrin

Results Chemotactic and adhesive signals compete & those two forces lead to a directed haptotactic movement

Conclusion Mature DCs activated ß2 integrin and cytoskeletal polarization upon contact with immonilized CCL21  haptokinetic movement CCL19 did not induce adhesion but cellular polarization  chemotactic movement Combination of CCL19/21 lead to directionally biased haptokinetic migration During their mirgation DCs generated a truncated version of CCL21 – Immobiliezd CCL21 dictates the PW – Soluble factors direction of migration

The End !!!Thank you for your attention!!! ??Question??

Introduction