Targeted delivery of antigen processing inhibitors to antigen presenting cells via mannose receptors.
Targeted delivery of antigen processing inhibitors to antigen presenting cells via mannose receptors.
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通过甘露糖受体将抗原加工抑制剂的靶向递送到抗原呈递细胞。
DOI：
10.1021/cb100008p
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发表时间：
2010-05-21
影响因子：
4
通讯作者：
Tabor, Alethea B.
中科院分区：
文献类型：
--
作者：
Raiber, Eun-Ang;Tulone, Calogero;Zhang, Yanjing;Martinez-Pomares, Luisa;Steed, Emily;Sponaas, Anna M.;Langhorne, Jean;Noursadeghi, Mandad;Chain, Benjamin M.;Tabor, Alethea B.
需要改进的化学抑制物来剖析特定的抗原处理酶的作用，并补充遗传模型。在这项研究中，我们探索了一类新型的天冬氨酸蛋白酶靶向抑制剂的体外和体内性质，其中胃抑素与甘露糖化白蛋白(MPC6)偶联，创建了一种具有更好的溶解性和选择性细胞亲和性的抑制剂。利用这些化合物，我们证明了MPC6是通过甘露糖受体促进的内吞作用被摄取的，导致抑制物在树突状细胞内的大内吞小泡中缓慢但持续地积累，并平行地抑制细胞内天冬氨酸蛋白酶的活性。细胞内蛋白酶活性的抑制与抗原处理活性的降低有关，但这是表位特异性的，优先抑制埋藏在紧凑的蛋白酶抗性蛋白结构域中的T细胞表位的处理。出乎意料的是，我们也证明了，使用猝灭的荧光底物，二硫键连接物在树突状细胞内发生很少或没有裂解，但这似乎不影响MPC6作为组织蛋白酶D和E的抑制物在体外和体内的活性。最后，我们发现MPC6在体内选择性地靶向于脾中的树突状细胞和巨噬细胞。在稳定状态下，接触非淋巴组织的途径非常有限，但在局部炎症部位，非淋巴组织的接触能力明显增强。因此，MPC6合成所采用的策略可能代表了一种更一般的方式，将化学抑制物输送到先天免疫系统的细胞，特别是在炎症部位。
Improved chemical inhibitors are required to dissect the role of specific antigen processing enzymes and to complement genetic models. In this study we explore the in vitro and in vivo properties of a novel class of targeted inhibitor of aspartic proteinases, in which pepstatin is coupled to mannosylated albumin (MPC6), creating an inhibitor with improved solubility and the potential for selective cell tropism. Using these compounds, we have demonstrated that MPC6 is taken up via mannose receptor facilitated endocytosis, leading to a slow but continuous accumulation of inhibitor within large endocytic vesicles within dendritic cells, and a parallel inhibition of intracellular aspartic proteinase activity. Inhibition of intracellular proteinase activity is associated with reduction in antigen processing activity, but this is epitope specific, preferentially inhibiting processing of T cell epitopes buried within compact proteinase-resistant protein domains. Unexpectedly, we have also demonstrated, using quenched fluorescent substrates, that little or no cleavage of the disulfide linker takes place within dendritic cells, but this does not appear to affect the activity of MPC6 as an inhibitor of cathepsins D and E in vitro and in vivo. Finally, we have shown that MPC6 selectively targets dendritic cells and macrophages in spleen in vivo. Access to non-lymphoid tissues is very limited in the steady state, but is strongly enhanced at local sites of inflammation. The strategy adopted for MPC6 synthesis may therefore represent a more general way to deliver chemical inhibitors to cells of the innate immune system, especially at sites of inflammation.
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影响因子：
56.9
作者：
Blander, JM;Medzhitov, R
通讯作者：
Medzhitov, R
影响因子：
15.3
作者：
Bonifaz, L;Bonnyay, D;Mahnke, K;Rivera, M;Nussenzweig, MC;Steinman, RM
通讯作者：
Steinman, RM
影响因子：
3.2
作者：
Free, P;Hurley, CA;Tabor, AB
通讯作者：
Tabor, AB
影响因子：
4.8
作者：
Frison, N;Taylor, ME;Roche, AC
通讯作者：
Roche, AC
DOI：
10.1073/pnas.0509035102
发表时间：
2005-12-13
影响因子：
11.1
作者：
Austin, CD;Wen, XH;Scales, SJ
通讯作者：
Scales, SJ