Lee K D, Oh Y K, Portnoy D A, Swanson J A
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
J Biol Chem. 1996 Mar 29;271(13):7249-52.
The cytosolic space of cells is an important but relatively inaccessible target for the delivery of therapeutic macromolecules. Here we describe the efficient delivery of macromolecules into the cytosolic space of macrophages from liposomes that contain listeriolysin O (LLO), the hemolytic protein of Listeria monocytogenes that normally mediates bacterial passage from phagosomes into cytosol. LLO was purified and encapsulated inside pH-sensitive liposomes, along with other molecules to be delivered. When internalized by bone marrow-derived macrophages, these liposomes rapidly released encapsulated fluorescent dye, first into endosomes and then into the cytosol, without measurably harming the cells. Furthermore, these liposomes efficiently delivered encapsulated ovalbumin to the cytosolic pathway of antigen processing and presentation, as measured by the major histocompatibility complex (MHC) class I-restricted presentation of peptides derived from ovalbumin. Delivery was significantly better than that obtained by other currently available liposome formulations. LLO-containing liposomes should therefore provide an efficient vehicle for delivery of antigens or therapeutic molecules in vivo.
细胞的胞质空间是治疗性大分子递送的一个重要但相对难以触及的靶点。在此，我们描述了将大分子从含有溶菌酶O（LLO）的脂质体高效递送至巨噬细胞的胞质空间，LLO是单核细胞增生李斯特菌的溶血蛋白，通常介导细菌从吞噬体进入胞质溶胶。LLO被纯化并与其他待递送分子一起封装在pH敏感脂质体内。当被骨髓来源的巨噬细胞内化时，这些脂质体迅速释放封装的荧光染料，首先释放到内体中，然后释放到胞质溶胶中，且未对细胞造成可测量的损害。此外，通过主要组织相容性复合体（MHC）I类限制的源自卵清蛋白的肽的呈递来衡量，这些脂质体将封装的卵清蛋白高效递送至抗原加工和呈递的胞质途径。递送效果明显优于目前其他可用的脂质体制剂。因此，含LLO的脂质体应能为体内抗原或治疗分子的递送提供一种有效的载体。
