3-Dimensional organization and dynamics of the microsporidian polar tube invasion machinery
Year: 2020
Type: article
Abstract: Microsporidia, a divergent group of single-celled eukaryotic parasites, harness a specialized harpoon-like invasion apparatus called the polar tube (PT) to gain entry into host cells.The PT is tightly coiled within the transmissible extracellular spore, and is about 20 times the length of the spore.Once triggered, the PT is rapidly ejected and is thought to penetrate the host cell, acting as a conduit for the transfer of infectious cargo into the host.The organization of this specialized infection apparatus in the spore, how it is deployed, and how the nucleus and other large cargo are transported through the narrow PT are not well understood.Here we use serial block-face scanning electron microscopy to reveal the 3-dimensional architecture of the PT and its relative spatial orientation to other organelles within the spore.Using high-speed optical microscopy, we also capture and quantify the entire PT germination process of three human-infecting microsporidian species in vitro: Anncaliia algerae, Encephalitozoon hellem and E. intestinalis.Our results show that the emerging PT experiences very high accelerating forces to reach velocities exceeding 300 μm�s -1 , and that firing kinetics differ markedly between species.Live-cell imaging reveals that the nucleus, which is at least 7 times larger than the diameter of the PT, undergoes extreme deformation to fit through the narrow tube, and moves at speeds comparable to PT extension.Our study sheds new light on the 3-dimensional organization, dynamics, and mechanism of PT extrusion, and shows how infectious cargo moves through the tube to initiate infection. Author summaryMicrosporidia infect a wide range of hosts: from economically important invertebrates such as silkworms and honey bees, to vertebrates including humans, where infection in immunocompromised patients can be fatal.In order to infect the host, microsporidia utilize a unique harpoon-like invasion organelle called the polar tube (PT), which serves as a
Source: PLoS Pathogens
Authors: Pattana Jaroenlak, Michael Cammer, Alina Davydov, Joseph Sall, Mahrukh Usmani, Feng-Xia Liang, Damian C. Ekiert, Gira Bhabha
Institutions: New York University, NYU Langone Health
Language: English
Subfield: Parasitology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,500
Awards: Ultrastructure and mechanism of the harpoon-like invasion machinery in microsporidian parasites, G3584301129, PD-1 Function, Signaling, and Regulation During Viral Infection, Scanning Electron Microscope with 3View, G4601239455, Structural basis of the polar tube invasion machinery from microsporidia parasites, G7680026891, Cancer Center Support Grant, Structure and function of MCE systems in bacteria
OpenAlex ID: W3087402952