Inhibition of inositol kinase B controls acute and chronic graft-versus-host disease

T-cell activation leads to regulated increases in cytoplasmic calcium through inositol 1,4,5-triphosphate (IP3), a process balanced by phosphorylation and inactivation of IP3 by inositol 1,4,5-trisphosphate 3-kinase B (Itpkb). The investigators demonstrate that inhibition of Itpkb sustains increased intracellular Ca, leads to T-cell apoptosis, and inhibits graft-versus-host disease without impairing graft-versus-leukemia effects.