CSF1R Inhibition Promotes Neuroinflammation and Behavioural Deficits during Graft-Versus-Host Disease in Mice

Chronic graft-versus-host disease (cGVHD) remains a significant complication of allogeneic hematopoietic stem cell transplantation. Central nervous system (CNS) involvement is becoming increasingly recognised, where brain-infiltrating donor MHC class II +bone marrow-derived macrophages (BMDM) are implicated mediators of pathology. Colony-stimulating factor 1 receptor (CSF1R)-dependent BMDM are established mediators of cutaneous and pulmonary cGVHD, and clinical trials assessing the efficacy of CSF1R antibody blockade to deplete macrophages are promising. We hypothesized that CSF1R antibody blockade may also be a useful strategy to prevent/treat CNS cGVHD.