Host membrane lipids are trafficked to membranes of intravacuolar bacterium <i>Ehrlichia chaffeensis</i>
Mingqun Lin, Giovanna Grandinetti, Lisa M. Hartnell, Donald Bliss, Sriram Subramaniam, Yasuko Rikihisa
Abstract
Significance Biological membranes are essential for life. Although bacteria and eukaryotic cells have evolved to produce membranes of different compositions, several bacterial pathogens can hijack and utilize host-synthesized membrane lipids. Here, we show that an obligatory intracellular pathogen, Ehrlichia chaffeensis , deficient in biosynthesis of cholesterol and some glycerophospholipids, actively acquires host-derived membrane components within membrane-bound inclusions (vacuoles). The trafficking of host membrane components to Ehrlichia and membrane-bound inclusions appears to occur via endocytosis and autophagy induced by a bacteria-secreted protein. Numerous intraluminal vesicles were found in Ehrlichia inclusions that may function as a membrane reserve for rapid proliferation of Ehrlichia . Our findings provide insights into host membrane assimilation by an intracellular pathogen, which can be exploited for antibacterial therapy.