Udono Heiichiro
Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Acta Med Okayama. 2012;66(1):1-6. doi: 10.18926/AMO/48075.
Dendritic cells (DCs) take up soluble- or cell-associated antigens and digest them, delivering fragments to the MHC class I pathway to display antigenic peptides to CD8(+) T cells, a process known as cross-presentation. The pathway requires that, in order to be degraded by proteosomes, the extracellular antigens must have access to the cytosol across the endosomal membranes. Although the cross-presentation phenomena was first identified in the 1970s, the molecular mechanism responsible for the translocation is still not fully understood. In this context, we have recently found that cytosolic heat shock protein (HSP)90 translocates internalized antigen to the cytosol in DCs. Our results revealed the important role that cytosolic HSP90 plays in cross-presentation by pulling out endosomal antigen to the cytosol.
树突状细胞（DCs）摄取可溶性或细胞相关抗原并将其消化，将片段递送至MHC I类途径以向CD8(+) T细胞展示抗原肽，这一过程称为交叉呈递。该途径要求，为了被蛋白酶体降解，细胞外抗原必须穿过内体膜进入细胞质。尽管交叉呈递现象在20世纪70年代首次被发现，但其负责转运的分子机制仍未完全被理解。在此背景下，我们最近发现细胞质热休克蛋白（HSP）90将内化抗原转运至DCs的细胞质中。我们的结果揭示了细胞质HSP90通过将内体抗原拉至细胞质在交叉呈递中所起的重要作用。
