用于肿瘤疫苗接种目的的树突细胞(DC)的离体产生和装载是费力且昂贵的。直接皮内(i.d.)施用肿瘤相关抗原可能是一种有吸引力的替代方法,前提是可以实现适当活化的皮肤DC的有效摄取和交叉呈递。这里,我们比较了从MART-1转导的急性髓系白血病(AML)HL60细胞获得的相对较小的凋亡气泡(直径~0.1-1μm)的i.d.在生理高度相关的人皮肤外植体模型中,较大的凋亡细胞残留物(ACR;2-10μm)。48小时后,单独注射荧光标记的ACRs或气泡不会影响皮肤活检中迁移的DC亚群的数量或分布。但导致共刺激分子CD83和CD86在摄入凋亡物质的皮肤DC上普遍上调。我们先前已经表明,i.d.施用GM-CSF和IL-4导致成熟且高度T细胞刺激性CD11hiCD1aCD14-真皮DC亚群的优先迁移。这里,我们发现GM-CSF和IL-4与ACRs或气泡一起共同注射导致该真皮DC亚群的摄取效率为7.6%(±6.1%)和19.1%(±15.9%),分别,因此显示出明显更高的气泡摄取频率(P<0.02)。肿瘤来源的气泡的皮内递送不会影响迁移皮肤DC的T细胞引发和TH偏斜能力。然而,与ACR的i.d.给药相反,注射气泡导致MART-1有效交叉呈递至特异性CD8+效应T细胞。我们得出的结论是,通过皮肤递送的凋亡性气泡疫苗可能会提供一种有吸引力的,广泛适用,癌症免疫疗法。
The generation and loading of dendritic cells (DC) ex-vivo for 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 of i.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 that i.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.