As two of the most widely used adjuvants, aluminum hydroxide and the oil-in-water emulsion MF59 have their intrinsic limitations: classical aluminum gel induces only weak cellular immune responses while MF59 cannot be used as an antigen delivery system due to its poor physical interaction with antigen molecules. Herein, we combined these two adjuvants and constructed a novel nano-vaccine delivery system by inserting aluminum hydroxide into the surface of a modified MF59 nano-emulsion (AlNEs). A model antigen ovalbumin (OVA) and an immune potentiator CpG were adsorbed on the surface of AlNEs (hereinafter AlNEs-OVA-CpG) through a facile mixing step. After subcutaneous injection, AlNEs-OVA-CpG effectively drained to lymph nodes, delivered both cargos into lymph node-resident antigen presenting cells (APCs), and escaped from lysosomes into the cytoplasm, resulting in enhanced antigen cross-presentation. Finally, AlNEs-OVA-CpG induced potent antigen-specific humoral and cellular immune responses, which significantly inhibited tumor growth and prolonged mice survival in a EG7-OVA tumor model. In sum, our results suggested that AlNEs have a great prospect to induce CD8⁺ T cell responses for subunit antigens.

作为最广泛使用的两种佐剂，氢氧化铝和水包油乳剂 MF59 有其固有的局限性：经典的铝凝胶仅诱导微弱的细胞免疫反应，而 MF59 由于其较差的物理相互作用而不能用作抗原递送系统与抗原分子。在此，我们将这两种佐剂结合起来，通过将氢氧化铝插入改性的 MF59 纳米乳液 (AlNEs) 的表面，构建了一种新型的纳米疫苗递送系统。通过简单的混合步骤，模型抗原卵白蛋白（OVA）和免疫增强剂CpG被吸附在AlNEs（以下称为AlNEs-OVA-CpG）的表面。皮下注射后，AlNEs-OVA-CpG 有效地引流到淋巴结，将两种货物输送到淋巴结驻留抗原呈递细胞 (APC)，并从溶酶体逃逸到细胞质中，导致抗原交叉呈递增强。最后，AlNEs-OVA-CpG 诱导有效的抗原特异性体液和细胞免疫反应，在 EG7-OVA 肿瘤模型中显着抑制肿瘤生长并延长小鼠存活时间。总之，我们的结果表明，AlNEs 在诱导 CD8 方面具有很大的前景。⁺ T 细胞对亚单位抗原的反应。