This invention relates to the field of therapeutics. Most specifically, the invention provides methods of generating conditionally expressing vectors for one or more immunomodulators or therapeutic proteins under the control of a gene expression modulation system in the presence of activating ligand and uses for therapeutic purposes in animals. These vector may be provided to treat a variety of disorders, e.g., neoplastic disorders, infectious diseases, ocular diseases, lysosomal storage diseases, or liver diseases, through direct injection or through in vitro engineered cells, such as dendritic cells.本發明關於治療劑之領域。最具體而言,本發明提供產製條件性表現載體之方法及在動物體內供治療目的之用途,該等載體在活化配體存在之基因表現調節系統之控制下表現一或多種免疫調節劑或治療性蛋白質。該等載體可經由直接注射或經由活體外工程化細胞(諸如樹突細胞)提供以治療各種疾病,例如腫瘤疾病、感染性疾病、眼疾病、溶酶體貯積病或肝疾病。