Department of Physics, SUPA, University of Strathclyde, Glasgow, United Kingdom.
Wellcome Centre for Integrative Parasitology (WCIP) University of Glasgow, Glasgow, United Kingdom.
Front Cell Infect Microbiol. 2022 Jun 14;12:903957. doi: 10.3389/fcimb.2022.903957. eCollection 2022.
Human African Trypanosomiasis (HAT) is a disease caused by the extracellular parasite that affects the central nervous system (CNS) during the chronic stage of the infection, inducing neuroinflammation, coma, and death if left untreated. However, little is known about the structural change happening in the brain as result of the infection. So far, infection-induced neuroinflammation has been observed with conventional methods, such as immunohistochemistry, electron microscopy, and 2-photon microscopy only in small portions of the brain, which may not be representative of the disease. In this paper, we have used a newly-developed light-sheet illuminator to image the level of neuroinflammation in chronically infected mice and compared it to naïve controls. This system was developed for imaging in combination with the Mesolens objective lens, providing fast sub-cellular resolution for tens of mm-large imaging volumes. The mouse brain specimens were cleared using CUBIC+, followed by antibody staining to locate Glial Fibrillary Acid Protein (GFAP) expressing cells, primarily astrocytes and ependymocytes, used here as a proxy for cell reactivity and gliosis. The large capture volume allowed us to detect GFAP cells and spatially resolve the response to infection. Based on morphometric analyses and spatial distribution of GFAP cells, our data demonstrates a significant increase in cell dendrite branching around the lateral ventricle, as well as dorsal and ventral third ventricles, that are negatively correlated with the branch extension in distal sites from the circumventricular spaces. To our knowledge, this is the first report highlighting the potential of light-sheet mesoscopy to characterise the inflammatory responses of the mouse brain to parasitic infection at the cellular level in intact cleared organs, opening new avenues for the development of new mesoscale imaging techniques for the study of host-pathogen interactions.
人类非洲锥虫病（HAT）是一种由寄生虫引起的疾病，在感染的慢性阶段会影响中枢神经系统（CNS），引发神经炎症、昏迷，如果不治疗会导致死亡。然而，人们对感染导致的大脑结构变化知之甚少。到目前为止，感染诱导的神经炎症仅通过常规方法（如免疫组织化学、电子显微镜和双光子显微镜）在大脑的一小部分观察到，这可能不能代表疾病的全貌。在本文中，我们使用了一种新开发的光片照明器来对慢性感染的小鼠进行神经炎症水平成像，并将其与未感染的对照进行比较。该系统是与 Mesolens 物镜结合开发的，可提供快速的亚细胞分辨率，适用于数十毫米大的成像体积。小鼠脑标本使用 CUBIC+进行清除，然后进行抗体染色以定位胶质纤维酸性蛋白（GFAP）表达细胞，主要是星形胶质细胞和室管膜细胞，这里用作细胞反应性和神经胶质增生的替代物。大的捕获体积使我们能够检测到 GFAP 细胞，并对感染的反应进行空间分辨。基于形态计量分析和 GFAP 细胞的空间分布，我们的数据表明，在侧脑室周围以及背侧和腹侧第三脑室周围，细胞树突分支显著增加，这与从室周间隙远端部位的分支延伸呈负相关。据我们所知，这是首次报道强调光片介观显微镜在完整清除器官中以细胞水平对感染导致的小鼠大脑炎症反应进行特征描述的潜力，为开发用于宿主-病原体相互作用研究的新的介观成像技术开辟了新的途径。
