Ehrlichia subversion of host innate responses.
Anaplasma (formerly Ehrlichia) phagocytophilum and Ehrlichia chaffeensis, upon infection of humans, replicate in host leukocyte granulocytes and monocytes/macrophages, respectively. These unusual Gram-negative bacteria lack genes for biosynthesis of the lipopolysaccharide and peptidoglycan that activate host leukocytes. Caveolae-mediated endocytosis directs A. phagocytophilum and E. chaffeensis to an intracellular compartment secluded from oxygen-dependent and -independent killing. Furthermore, these bacteria orchestrate a remarkable series of events that culminate in suppression of NADPH oxidase, phagocyte activation and differentiation pathways, apoptosis, and interferon-gamma signaling in host leukocytes. They offer a fascinating example of how pathogens employ intricate strategies to usurp and subvert host cell function.
Rikihisa
Yasuko
Y
Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA. rikihisa.1@osu.edu
D000709:Anaplasma / Q000276:immunology / Q000472:pathogenicity*; D000712:Anaplasmosis / Q000276:immunology* / Q000382:microbiology; D017209:Apoptosis; D018469:Ehrlichia chaffeensis / Q000276:immunology / Q000472:pathogenicity*; D016873:Ehrlichiosis / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D007113:Immunity, Innate; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D008247:Lysosomes / Q000276:immunology / Q000382:microbiology; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D010587:Phagocytosis / Q000276:immunology
D019255:NADPH Oxidases