A method for treating a disease caused by protein retention in the endoplasmicreticulum(ER) with a sarcoplasmic/endoplasmic reticulum calcium ATPase pump inhibitorencapsulatedin a polymer nanoparticle. The polymer nanoparticle is surface-modified suchthat it is targetedto the ER. The inhibitor reduces protein retention in the ER and theencapsulation lowers sideeffects of the inhibitor, e.g., cytotoxicity, as compared to administering theinhibitor withoutencapsulation. Also disclosed is a pharmaceutical composition that can be usedfor carrying outthe method. Further provided is a transgenic mouse carrying in its genome aheterologousnucleic acid that encodes an H338Y mutant gp91phox protein. The transgenicmouse can serve asa model for human chronic granulomatous disease.
