|Patients with corticosteroid-refractory acute graft-versus-host disease (aGVHD) have a low one-year survival rate. Identification and validation of novel targetable kinases in patients who experience corticosteroid-refractory-aGVHD may help improve outcomes. Kinase-specific proteomics of leukocytes from patients with corticosteroid-refractory-GVHD identified rho kinase type 1 (ROCK1) as the most significantly upregulated kinase. ROCK1/2 inhibition improved survival and histological GVHD severity in mice and was synergistic with JAK1/2 inhibition, without compromising graft-versus-leukemia-effects. ROCK1/2-inhibition in macrophages or dendritic cells prior to transfer reduced GVHD severity. Mechanistically, ROCK1/2 inhibition or ROCK1 knockdown interfered with CD80, CD86, MHC-II expression and IL-6, IL-1β, iNOS and TNF production in myeloid cells. This was accompanied by impaired T cell activation by dendritic cells and inhibition of cytoskeletal rearrangements, thereby reducing macrophage and DC migration. NF-κB signaling was reduced in myeloid cells following ROCK1/2 inhibition. In conclusion, ROCK1/2 inhibition interferes with immune activation at multiple levels and reduces acute GVHD while maintaining GVL-effects, including in corticosteroid-refractory settings.
|Michal Rackiewicz, Zehan Hu, Nadia El Khawanky, Sanaz Taromi, Hana Andrlova, Hemin Faraidun, Stefanie Walter, Dietmar Pfeifer, Marie Follo, Johannes Waldschmidt, Wolfgang Melchinger, Michael Rassner, Claudia Wehr, Annette Schmitt-Graeff, Sebastian Halbach, James Liao, Georg Häcker, Tilman Brummer, Joern Dengjel, Geoffroy Andrieux, Robert Grosse, Sonia Tugues, Bruce R. Blazar, Burkhard Becher, Melanie Boerries & Robert Zeiser
|Gel and Blot data was analyzed with LabImage 1D