title: In situloading of skin dendritic cells with apoptotic bleb-derived antigens for the induction of tumor-directed immunity.
abstract: The generation and loading of dendritic cells (DC)ex-vivofor tumor vaccination purposes is laborious and costly. Direct intradermal (i.d.) administration of tumor-associated antigens could be an attractive alternative approach, provided that efficient uptake and cross-presentation by appropriately activated skin DCs can be achieved. Here, we compare the efficiency ofi.d. delivery of relatively small apoptotic blebs (diameter ∼0.1-1 μm) derived from MART-1 transduced acute myeloid leukemia (AML) HL60 cells, to that of larger apoptotic cell remnants (ACR; 2-10 μm) in a physiologically highly relevant human skin explant model. Injection of either fluorescently-labelled ACRs or blebs alone did not affect the number or distribution of migrated DC subsets from skin biopsies after 48 hours, but resulted in a general up-regulation of the co-stimulatory molecules CD83 and CD86 on skin DCs that had ingested apoptotic material. We have previously shown thati.d. administration of GM-CSF and IL-4 resulted in preferential migration of a mature and highly T cell-stimulatory CD11hiCD1a+CD14-dermal DC subset. Here, we found that co-injection of GM-CSF and IL-4 together with either ACRs or blebs resulted in uptake efficiencies within this dermal DC subset of 7.6% (±6.1%) and 19.1% (±15.9%), respectively, thus revealing a significantly higher uptake frequency of blebs (P< 0.02). Intradermal delivery of tumor-derived blebs did not affect the T-cell priming and TH-skewing abilities of migratory skin DC. Nevertheless, in contrast to i.d. administration of ACR, the injection of blebs lead to effective cross-presentation of MART-1 to specific CD8+effector T cells. We conclude that apoptotic bleb-based vaccines delivered through the skin may offer an attractive, and broadly applicable, cancer immunotherapy.
authors.affiliation: Department of Hematology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Jurjen M
authors.initials: JM
authors.lastname: Ruben
authors.affiliation: Department of Hematology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands ; Department of Pathology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Hetty J
authors.initials: HJ
authors.lastname: Bontkes
authors.affiliation: Department of Hematology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Theresia M
authors.initials: TM
authors.lastname: Westers
authors.affiliation: Department of Pathology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Hooijberg
authors.affiliation: Department of Hematology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Gert J
authors.initials: GJ
authors.lastname: Ossenkoppele
authors.affiliation: Department of Hematology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Arjan A
authors.initials: AA
authors.lastname: van de Loosdrecht
authors.affiliation: Department of Medical Oncology; VU University Medical Center; Cancer Center Amsterdam ; Amsterdam, The Netherlands.
authors.forename: Tanja D
authors.initials: TD
authors.lastname: de Gruijl
keywords: 4/GM, IL-4 and GM-CSF; ACR, apoptotic cell remnant; AML, acute myeloid leukemia; CFSE, carboxyfluorescein succinimidyl ester; DC, dendritic cell; DDC, dermal DC; GM-CSF, granulocyte-macrophage colony-stimulating factor; HLA, human leukocyte antigen; HSCT, hematopoietic stem cell transplantation; IFN, interferon; IL, interleukin; Ig, immune globulin; LC, Langerhans cell; LN, lymph node; MART-1/melan-A, melanoma antigen recognized by T cell 1; MLR, mixed leukocyte reaction; MoDC, monocyte-derived dendritic cell; TAA, tumor-associated antigen; TH, T Helper; TLR, Toll-like receptor; TNFα, tumor necrosis factor α; apoptotic cells; blebs; cross-presentation; dendritic cells; dermis; i.d., intradermal; phagocytosis; skin