Abstract: It has been discovered that reducing, inhibiting or preventing the expression of immunosuppressive cytokines or tolergenic agents in antigen presenting cells improves the ability of the antigen presenting cell to promote an immune response. One embodiment provides a genetically engineered antigen presenting cell that has reduced or no expression of IL-10. Preferred antigen presenting cells are dendritic cells. Expression of IL-10 can be inhibited or blocked by genetically engineering the antigen presenting cell to express inhibitory nucleic acids that inhibit or prevent the expression mRNA encoding immunosuppressive cytokines. Inhibitory nucleic acids include siRNA, antisense RNA, antisense DNA, microRNA, and enzymatic nucleic acids that target mRNA encoding immunosuppressive cytokines. Immunosuppressive cytokines include, but are not limited to IL-10, TGF-?, IL-27, IL-35, or combinations thereof. Tolerogenic agents include but are not limited to indoleamine 2,3-dioxygenase.