DataSheet_1_Leishmania infection-induced multinucleated giant cell formation via upregulation of ATP6V0D2 expression.pdf

Leishmaniasis is caused by infection with protozoan parasites of the genus Leishmania. In both clinical and experimental visceral leishmaniasis, macrophage multinucleation is observed in parasitized tissues. However, the feature and the mechanism of macrophage multinucleation remained unclear. Here, we report that infection of Leishmania donovani, a causative agent of visceral leishmaniasis, induces multinucleation of bone marrow-derived macrophages (BMDMs) in vitro. When these infection-induced multinucleated macrophages were compared with cytokine-induced multinucleated giant cells, the former had higher phagocytic activity on red blood cells but no apparent changes on phagocytosis of latex beads. BMDMs infected with L. donovani had increased expression of ATP6V0D2, one of the components of V-ATPase, which was also upregulated in the spleen of infected mice. Infection-induced ATP6V0D2 localized in a cytoplasmic compartment, which did not overlap with the mitochondria, endoplasmic reticulum, or lysosomes. When ATP6V0D2 expression was recombinantly induced in BMDMs, the formation of multinucleated macrophages was induced as seen in the infected macrophages. Taken together, L. donovani infection induces multinucleation of macrophages via ATP6V0D2 upregulation leading to a unique metamorphosis of the macrophages toward hemophagocytes.

利什曼病（Leishmaniasis）由利什曼原虫属（Leishmania）的原生动物寄生虫感染所引发。在临床与实验性内脏利什曼病（visceral leishmaniasis）中，感染宿主的受累组织内均可观测到巨噬细胞多核化现象，但该过程的具体特征与潜在机制迄今尚未阐明。本研究发现，作为内脏利什曼病的致病菌，杜氏利什曼原虫（Leishmania donovani）可在体外诱导骨髓来源巨噬细胞（bone marrow-derived macrophages, BMDMs）发生多核化。将该感染诱导的多核巨噬细胞与细胞因子诱导的多核巨细胞进行比对后发现，前者对红细胞（red blood cells）的吞噬活性显著更高，但对乳胶微珠（latex beads）的吞噬能力无明显变化。感染杜氏利什曼原虫的BMDMs中，V-ATP酶（V-ATPase）的组成亚基ATP6V0D2的表达水平显著上调，该基因在感染小鼠的脾脏组织中同样呈现表达上调趋势。感染诱导产生的ATP6V0D2定位于胞质区域，且不与线粒体、内质网（endoplasmic reticulum）或溶酶体（lysosomes）发生共定位。在BMDMs中通过重组手段诱导ATP6V0D2表达时，可诱导多核巨噬细胞的形成，该表型与感染状态下的巨噬细胞一致。综上，杜氏利什曼原虫感染通过上调ATP6V0D2的表达，诱导巨噬细胞发生多核化，使巨噬细胞向噬血细胞方向发生独特的表型重塑。