A Novel Agent SL-401 Targeting Interleukin-3 (IL-3)-Receptor Blocks Plasmacytoid Dendritic Cell (pDC)-induced Myeloma Cell Growth and Overcomes Drug Resistance

IL-3 Directed to IL-3 receptor SL-401 is a recombinant protein expressed in E. coli from a hybrid gene comprised of the DNA sequence of human IL-3 fused to the DNA sequence of truncated DT consisting of its catalytic and translocation, but not binding, domains. The IL-3 domain of SL-401, which replaces the binding domain of DT, targets SL-401 to cells that over-express the IL-3R.