Utilizing a Reconfigured Hdl Particle to Target and Deliver Sirna to Mantle Cell Lymphoma Cells

We have reconfigured the biological high-density lipoprotein (HDL) particle such that it has a high preference for binding and delivering siRNA to a subclass of B-cell lymphoma, mantle cell lymphoma (MCL) cells. We utilize a chimeric protein comprised of a CD20 specific single-chain variable fragment antibody fused to apolipoprotein A-1, in our HDL reconstitution (chimeric-rHDL). The amphipathic apoA-1 component of the chimera is proposed to circumscribe the edge of a discoidal lipid bilayer (see figure). The size and function of the chimeric-rHDL particle has been evaluated by biophysical and biochemical techniques. Fluorescence-activated cell sorting studies showed that the chimeric-rHDL exhibits much higher binding towards MCL cells compared to apoA-1-rHDL particles. Interestingly, immunoblot studies show that the protein cyclinD1, that is responsible for the G1→S transition in MCL cells, is efficiently knocked down when incubated with cholesterol-linked-siRNA (specific for cyclinD1) incorporated into chimeric-rHDL particles (see figure). The results suggest chimeric rHDL carrying siRNA tethered via covalent linkage to cholesterol, provides a means to deliver siRNA specifically to CD20 expressing cells.View Large Image | View Hi-Res Image | Download PowerPoint Slide