scholarly journals Adult Drosophila Lack Hematopoiesis but Rely on a Blood Cell Reservoir at the Respiratory Epithelia to Relay Infection Signals to Surrounding Tissues

2019 ◽  
Vol 51 (6) ◽  
pp. 787-803.e5 ◽  
Author(s):  
Pablo Sanchez Bosch ◽  
Kalpana Makhijani ◽  
Leire Herboso ◽  
Katrina S. Gold ◽  
Rowan Baginsky ◽  
...  
Keyword(s):  
Blood Cell ◽  
Respiratory Epithelia ◽  
Adult Drosophila

scholarly journals Blood cells of adult Drosophila do not expand, but control survival after bacterial infection by induction of Drosocin around their reservoir at the respiratory epithelia

2019 ◽  
Author(s):  
Pablo Sanchez Bosch ◽  
Kalpana Makhijani ◽  
Leire Herboso ◽  
Katrina S Gold ◽  
Rowan Baginsky ◽  
...  
Keyword(s):  
Blood Cell ◽  
Bacterial Infection ◽  
Blood Cells ◽  
Fat Body ◽  
Cell System ◽  
Respiratory Epithelia ◽  
Vertebrate Tissue ◽  
Peptide Gene ◽  
Control Survival ◽  
Adult Drosophila

SummaryDrosophila melanogaster has been an excellent model for innate immunity, but the role and regulation of adult blood cells and organismal immunity have remained incompletely understood. Here we address these questions in a comprehensive investigation of the blood cell system in adult Drosophila. As a central finding, we reveal the largest reservoir of blood cells (hemocytes) at the respiratory epithelia (tracheal air sacs) and fat body of the thorax and head. We show that most hemocytes of adult Drosophila are phagocytic macrophages (plasmatocytes), derived by more than 60% from the embryonic lineage that parallels vertebrate tissue macrophages. Surprisingly, in contrast to hemocytes at the larval stage, we find no capacity of the adult blood cell system to expand. Instead, we demonstrate its central role in relaying an innate immune response to tissues surrounding the blood cell reservoir: Hemocytes, through Imd signaling and the Jak/Stat pathway ligand Upd3, act as sentinels of bacterial infection that induce expression of the antimicrobial peptide gene Drosocin in the respiratory epithelia and colocalizing domains of the fat body. We demonstrate that endogenous Drosocin expression in these tissues promotes animal survival after bacterial infection. Our work identifies the first molecular step in a new relay of organismal immunity, establishing adult Drosophila as model to dissect mechanisms of inter-organ immunity.

Methods for making stereoslides and -prints, with freeze-etched olfactory epithelium as example

1984 ◽  
Vol 42 ◽  
pp. 704-705
Author(s):  
Bert Ph. M. Menco ◽  
Ido F. Menco ◽  
Frans L.T. Verdonk
Keyword(s):  
Electron Microscope ◽  
Olfactory Epithelium ◽  
Three Dimensional ◽  
Supporting Cell ◽  
Structural Features ◽  
Extensive Study ◽  
Sprague Dawley ◽  
Freezing Method ◽  
Respiratory Epithelia ◽  
Three Dimensional Presentation

Previously we presented an extensive study of the distributions of intramembranous particles of structures in apical surfaces of nasal olfactory and respiratory epithelia of the Sprague-Dawley rat. For the same structures these distributions were compared in samples which were i) chemically fixed and cryo-protected with glycerol before cryo-fixation, after excision, and ii)ultra-rapidly frozen by means of the slam-freezing method. Since a three-dimensional presentation markedly improves visualization of structural features micrographs were presented as stereopairs. Two exposures were made by tiling the sample stage of the electron microscope 6° in either direction with an eucentric goniometer. The negatives (Agfa Pan 25 Professional) were reversed with Kodak Technical Pan Film 2415 developed in D76 1:1. The prints were made from these reversed negatives. As an example tight-junctional features of an olfactory supporting cell in a region where this cell conjoined with two other cells are presented (Fig. 1).

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