title: Evasion of innate immunity by parasitic protozoa.
abstract: Parasitic protozoa are a major cause of global infectious disease. These eukaryotic pathogens have evolved with the vertebrate immune system and typically produce long-lasting chronic infections. A critical step in their host interaction is the evasion of innate immune defenses. The ability to avoid attack by humoral effector mechanisms, such as complement lysis, is of particular importance to extracellular parasites, whereas intracellular protozoa must resist killing by lysosomal enzymes and toxic metabolites. They do so by remodeling the phagosomal compartments in which they reside and by interfering with signaling pathways that lead to cellular activation. In addition, there is growing evidence that protozoan pathogens modify the antigen-presenting and immunoregulatory functions of dendritic cells, a process that facilitates their evasion of both innate and adaptive immunity.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA. dsacks@nih.gov
authors.forename: David
authors.initials: D
authors.lastname: Sacks
authors.forename: Alan
authors.initials: A
authors.lastname: Sher
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000953:Antigens, Protozoan / Q000276:immunology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000469:parasitology; D002648:Child; D003713:Dendritic Cells / Q000276:immunology; D056890:Eukaryota / Q000276:immunology / Q000502:physiology*; D006790:Host-Parasite Interactions / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D007303:Insect Vectors / Q000469:parasitology; D018664:Interleukin-12 / Q000502:physiology; D007891:Leishmania / Q000502:physiology; D051379:Mice; D010588:Phagosomes / Q000469:parasitology*; D011528:Protozoan Infections / Q000276:immunology* / Q000469:parasitology; D011529:Protozoan Infections, Animal / Q000276:immunology / Q000469:parasitology; D015398:Signal Transduction; D014122:Toxoplasma / Q000502:physiology; D014345:Trypanosoma / Q000502:physiology
chemical_list: D000953:Antigens, Protozoan; D018664:Interleukin-12