Endothelial exosome plays a functional role during rickettsial infection

Yakun Liu, Changcheng Zhou, Zhengchen Su, Qing Chang, Yuan Qiu, Jiani Bei, Angelo Gaitas, Jie Xiao, Alexandra Drelich, Kamil Khanipov, Yang Jin, Georgiy Golovko, Tais B. Saito, Bin Gong

Research output: Contribution to journalArticlepeer-review

Abstract

Spotted fever group rickettsioses (SFRs) are devastating human infections. Vascular endothelial cells (ECs) are the primary targets of rickettsial infection. Edema resulting from EC barrier dysfunction occurs in the brain and lungs in most cases of lethal SFR, but the underlying mechanisms remain unclear. The aim of the study was to explore the potential role of Rickettsia-infected, EC-derived exosomes (Exos) during infection. Using size exclusion chromatography (SEC), we purified Exos from conditioned, filtered, bacterium-free media collected from Rickettsia parkeri-infected human umbilical vein ECs (HUVECs) (R-ECExos) and plasma of Rickettsia australis-or R. parkeri-infected mice (R-plsExos). We observed that rickettsial infection increased the release of heterogeneous plsExos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Compared to normal plsExos and ECExos, both R-plsExos and R-ECExos induced dysfunction of recipient normal brain microvascular ECs (BMECs). The effect of R-plsExos on mouse recipient BMEC barrier function is dose dependent. The effect of R-ECExos on human recipient BMEC barrier function is dependent on the exosomal RNA cargo. Next-generation sequencing analysis and stem-loop quantitative reverse transcription-PCR (RT-qPCR) validation revealed that rickettsial infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which potentially target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria. IMPORTANCE Spotted fever group rickettsioses are devastating human infections. Vascular endothelial cells are the primary targets of infection. Edema resulting from endothelial barrier dysfunction occurs in the brain and lungs in most cases of lethal rickettsioses, but the underlying mechanisms remain unclear. The aim of the study was to explore the potential role of Rickettsia-infected, endothelial cell-derived exosomes during infection. We observed that rickettsial infection increased the release of heterogeneous plasma Exos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Rickettsia-infected, endothelial cell-derived exosomes induced dysfunction of human recipient normal brain microvascular endothelial cells. The effect is dependent on the exosomal RNA cargo. Next-generation sequencing analysis revealed that rickettsial infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which potentially target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria.

Original languageEnglish (US)
Article numbere00769-21
JournalmBio
Volume12
Issue number3
DOIs
StatePublished - May 1 2021

Keywords

  • Barrier function
  • Endothelial barrier function
  • Endothelial cell
  • Exosome
  • Extracellular vesicle
  • Rickettsial infection
  • Spotted fever group rickettsial infection

ASJC Scopus subject areas

  • Microbiology
  • Virology

Fingerprint Dive into the research topics of 'Endothelial exosome plays a functional role during rickettsial infection'. Together they form a unique fingerprint.

Cite this