Figure 3.

Different strategies for the generation and administration of DC-based vaccines in AML. (1) (A) Leukemia-derived DCs can be directly generated by isolation and differentiation from AML blasts in vitro. (B) CD14⁺ monocytes from patients or healthy donors are differentiated into monocyte-derived DCs (mDCs). These mDCs are cultured together with (C) AML cell lysates or immunogenic apoptotic/necrotic AML cells (185) or (D) are electroporated with mRNA from AML cells (191) to ensure leukemia antigen loading. (E) As an additional in vitro approach, AML blast-mDC cell-fusion hybrids are artificially generated (196). (F) The DCs are then injected s.c. or i.v. into AML patients. (2) DCs can also be loaded and activated in vivo (188). DCs express the endocytosis receptor SIGLEC. Intravenous administration of an αSIGLEC H mAb conjugated to a leukemia antigen in the presence of CpG results in DC activation, antigen uptake and presentation. (3) Plasmacytoid DCs isolated from AML patients are activated and loaded with leukemia antigens ex vivo and are re-injected intralymphatically into lymph nodes (201). Ab, antibody; Ag, antigen; i.v. intravenously; pDCs, plasmacytoid DCs. s.c., subcutaneously.