title: Pyrimidinergic Receptor Activation Controls Toxoplasma gondii Infection in Macrophages.
abstract: Infection by the protozoan parasite Toxoplasma gondii is highly prevalent worldwide and may have serious clinical manifestations in immunocompromised patients. T. gondii is an obligate intracellular parasite that infects almost any cell type in mammalian hosts, including immune cells. The immune cells express purinergic P2 receptors in their membrane--subdivided into P2Y and P2X subfamilies--whose activation is important for infection control. Here, we examined the effect of treatment with UTP and UDP in mouse peritoneal macrophages infected with T. gondii tachyzoites. Treatment with these nucleotides reduced parasitic load by 90%, but did not increase the levels of the inflammatory mediators NO and ROS, nor did it modulate host cell death by apoptosis or necrosis. On the other hand, UTP and UDP treatments induced early egress of tachyzoites from infected macrophages, in a Ca2+-dependent manner, as shown by scanning electron microscopy analysis, and videomicroscopy. In subsequent infections, prematurely egressed parasites had reduced infectivity, and could neither replicate nor inhibit the fusion of lysosomes to the parasitophorous vacuole. The use of selective agonists and antagonists of the receptor subtypes P2Y2 and P2Y4 and P2Y6 showed that premature parasite egress may be mediated by the activation of these receptor subtypes. Our results suggest that the activity of P2Y host cell receptors controls T. gondii infection in macrophages, highlighting the importance of pyrimidinergic signaling for innate immune system response against infection. Finally the P2Y receptors should be considered as new target for the development of drugs against T. gondii infection.
authors.affiliation: Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Aline Cristina Abreu
authors.initials: AC
authors.lastname: Moreira-Souza
authors.affiliation: Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Ygor
authors.initials: Y
authors.lastname: Marinho
authors.affiliation: Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Gladys
authors.initials: G
authors.lastname: Correa
authors.affiliation: Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Laboratório de Inovações, Terapias, Ensino e Bioprodutos (LITEB), Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, 21.040-900, Brazil; Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Giani França
authors.initials: GF
authors.lastname: Santoro
authors.affiliation: Laboratório de Inovações, Terapias, Ensino e Bioprodutos (LITEB), Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, 21.040-900, Brazil; Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, 24020-140, Brazil.
authors.forename: Claudia Mara Lara Melo
authors.initials: CM
authors.lastname: Coutinho
authors.affiliation: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Rossiane Claudia
authors.initials: RC
authors.lastname: Vommaro
authors.affiliation: Laboratório de Imunofisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil; Instituto Nacional de Ciência e Tecnologia para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica (INPeTAm/UFRJ), Rio de Janeiro, RJ, 21941-902, Brazil.
authors.forename: Robson
authors.initials: R
authors.lastname: Coutinho-Silva
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006790:Host-Parasite Interactions / Q000187:drug effects; D008264:Macrophages / Q000378:metabolism / Q000469:parasitology* / Q000648:ultrastructure; D017737:Macrophages, Peritoneal / Q000378:metabolism / Q000469:parasitology* / Q000648:ultrastructure; D008297:Male; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009569:Nitric Oxide / Q000378:metabolism; D058912:Purinergic P2Y Receptor Agonists / Q000494:pharmacology; D058921:Purinergic P2Y Receptor Antagonists / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism; D058470:Receptors, Purinergic P2Y / Q000378:metabolism*; D013498:Suramin / Q000494:pharmacology; D014122:Toxoplasma / Q000502:physiology*; D014530:Uridine Diphosphate / Q000494:pharmacology; D014544:Uridine Triphosphate / Q000494:pharmacology
chemical_list: D058912:Purinergic P2Y Receptor Agonists; D058921:Purinergic P2Y Receptor Antagonists; D017382:Reactive Oxygen Species; D058470:Receptors, Purinergic P2Y; D009569:Nitric Oxide; D014530:Uridine Diphosphate; D013498:Suramin; D014544:Uridine Triphosphate