Quantitative single-cell analysis of Leishmania major amastigote differentiation demonstrates variably extended expression of the lipophosphoglycan (LPG) virulence factor in different host cell types.
Quantitative single-cell analysis of Leishmania major amastigote differentiation demonstrates variably extended expression of the lipophosphoglycan (LPG) virulence factor in different host cell types.
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DOI：
10.1371/journal.pntd.0010893
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发表时间：
2022-10
影响因子：
3.8
通讯作者：
中科院分区：
文献类型：
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利什曼原虫通过感染的白蛉载体沉积到哺乳动物宿主中后，立即遇到各种细胞类型并被吞噬。从那里，寄生虫可以转移到其他细胞类型，主要是巨噬细胞或树突细胞，在那里它们复制并诱导病理。在此期间，利什曼原虫细胞经历了一个戏剧性的转变，从能动的非复制的元循环阶段的非能动的复制无鞭毛体阶段，一个分化的过程，可以被称为无鞭毛体。为了在单细胞水平上遵循这一点，我们确定了一套定性或定量描绘无鞭毛体发生不同阶段的实验“地标”，包括无鞭毛体特异性标记物的新用途，这些标记物在前端或后端显示出有趣的细胞定位。我们比较了腹腔和骨髓来源的巨噬细胞（PEM，BMM）或树突状细胞（BMDC）的同步感染中的无鞭毛体发生。总体而言，标记物组表达显示出感染后的有序过渡，在宿主细胞类型之间具有相似的动力学，在12小时内出现几种无鞭毛体性状，随后在24小时后进行寄生虫复制，BMM或BMDC中的寄生虫启动DNA复制更慢。脂磷酸聚糖（LPG）是利什曼原虫毒力因子，促进宿主细胞中的代谢环建立，但在无鞭毛体中下降。而感染PEM的寄生虫在48小时内失去LPG表达，而感染BMM或BMDC的寄生虫在72小时时仍有>40%的LPG表达。major可以延长LPG在不同细胞内环境中的表达，从而延长其在原位和表达该关键毒力因子的寄生虫的细胞间转移期间促进感染性的功效。利什曼病是由锥虫属原虫利什曼原虫引起的一种重要的全球性健康问题。人类在携带有鞭毛的后环前鞭毛体阶段的白蛉叮咬后被利什曼原虫感染，此后的前24-48小时对感染的结果至关重要。在此期间，寄生虫被几种宿主细胞类型吞噬，在那里它们分化成圆形无鞭毛体阶段，适应细胞内存活和增殖，伴随着代谢和毒力因子表达的变化。我们开发了一套标记物，使我们能够在单细胞水平上监测前鞭毛体到无鞭毛体的分化（无鞭毛体发生）。两个显示无鞭毛体特异性表达，并定位于前部或后部区域。我们的标记套件使我们能够绘制在不同的宿主细胞环境中的无鞭毛体形成的过程，并确定相对于寄生虫复制的开始和毒力因子脂磷酸聚糖（LPG）的表达的无鞭毛体发育的时间。我们报告说，无鞭毛体的过程如下确定的事件发生之前，寄生虫复制序列。相反，寄生虫可以通过延长LPG表达来响应不同的宿主细胞环境，从而延长其在宿主细胞目的地内或在宿主细胞目的地之间转运的促感染性功能的持续时间。
Immediately following their deposition into the mammalian host by an infected sand fly vector, Leishmania parasites encounter and are engulfed by a variety of cell types. From there, parasites may transit to other cell types, primarily macrophages or dendritic cells, where they replicate and induce pathology. During this time, Leishmania cells undergo a dramatic transformation from the motile non-replicating metacyclic stage to the non-motile replicative amastigote stage, a differentiative process that can be termed amastigogenesis. To follow this at the single cell level, we identified a suite of experimental ‘landmarks’ delineating different stages of amastigogenesis qualitatively or quantitatively, including new uses of amastigote-specific markers that showed interesting cellular localizations at the anterior or posterior ends. We compared amastigogenesis in synchronous infections of peritoneal and bone-marrow derived macrophages (PEM, BMM) or dendritic cells (BMDC). Overall, the marker suite expression showed an orderly transition post-infection with similar kinetics between host cell types, with the emergence of several amastigote traits within 12 hours, followed by parasite replication after 24 hours, with parasites in BMM or BMDC initiating DNA replication more slowly. Lipophosphoglycan (LPG) is a Leishmania virulence factor that facilitates metacyclic establishment in host cells but declines in amastigotes. Whereas LPG expression was lost by parasites within PEM by 48 hours, >40% of the parasites infecting BMM or BMDC retained metacyclic-level LPG expression at 72 hr. Thus L. major may prolong LPG expression in different intracellular environments, thereby extending its efficacy in promoting infectivity in situ and during cell-to-cell transfer of parasites expressing this key virulence factor. Leishmaniasis caused by species of the trypanosomatid protozoan parasite Leishmania is an important widespread global health problem. Humans become infected by Leishmania following the bite of sand flies bearing the flagellated metacyclic promastigote stage, and the first 24–48 hours thereafter are critical to the outcome of infection. During this time, parasites are engulfed by several host cell types, where they differentiate into the rounded amastigote stage, adapted for intracellular survival and proliferation, with concomitant changes in metabolism and virulence factor expression. We developed a suite of markers that allowed us to monitor promastigote-to-amastigote differentiation (amastigogenesis) on a single-cell level. Two showed amastigote-specific expression and localized to the anterior or posterior regions. Our marker suite allowed us to chart the course of amastigogenesis in different host cell environments and to determine the timing of amastigote development relative to the initiation of parasite replication and the expression of the virulence factor lipophosphoglycan (LPG). We report that the amastigogenesis process follows a determined sequence of events that occurs prior to parasite replication. In contrast, parasites may respond to different host cell environments by prolonging LPG expression, thereby extending the duration of its pro-infectivity functions within or in transit between host cell destinations.
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DOI：
10.1084/jem.191.12.2121
发表时间：
2000-06-19
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Bogdan C;Donhauser N;Döring R;Röllinghoff M;Diefenbach A;Rittig MG
通讯作者：
Rittig MG
影响因子：
4.6
作者：
Kleinholz CL;Riek-Burchardt M;Seiß EA;Amore J;Gintschel P;Philipsen L;Bousso P;Relja B;Schraven B;Handschuh J;Mohr J;Müller AJ
通讯作者：
Müller AJ
影响因子：
3.1
作者：
Capul, Althea A.;Hickerson, Suzanne;Beverley, Stephen M.
通讯作者：
Beverley, Stephen M.
DOI：
10.1073/pnas.0900226106
发表时间：
2009-04-21
影响因子：
11.1
作者：
Guimaraes-Costa, Anderson B.;Nascimento, Michelle T. C.;Saraiva, Elvira M.
通讯作者：
Saraiva, Elvira M.
影响因子：
1.5
作者：
Holzer, TR;McMaster, WR;Forney, JD
通讯作者：
Forney, JD