title: E-ADA activity in lymphocytes of an experimental model of pythiosis treated with immunotherapy.
abstract: Pythiosis is a life-threatening disease caused by the oomycete Pythium insidiosum. Some authors have suggested the involvement of a Th2-like immune response in the infected host, which leads to extensive tissue damage. The switch from a Th2 to a Th1 response pattern is one hypothesis to explain the curative properties of immunotherapy. Taking into account the importance of immunotherapy for pythiosis treatment and the contribution of adenine nucleotides in the immunoregulation of the host, we evaluated the ecto-adenosine deaminase (E-ADA; EC 3·5.4·4) activity in lymphocytes from rabbits inoculated with P. insidiosum. Rabbits were inoculated with 1 milliliter of zoospores subcutaneously injected into the lateral thorax; after developing lesions, the rabbits received eight doses of immunotherapy. E-ADA activity was measured in lymphocytes and the adenine nucleotides and adenosine levels were quantitatively determined in serum. Rabbits with characteristic lesions of pythiosis showed a decreased E-ADA activity (82·36%), a decreased adenosine triphosphate concentration (54·04%) and a higher adenosine concentration (2·51 fold), when compared with controls, after 28 days of inoculation. However, after the immunotherapy, the rabbits showed an increase in the E-ADA activity when compared with control (78·62%), contributing for the change in the immune response. Our results reinforce the hypothesis that the change from a Th2 to a Th1 immune response with the participation of the purinergic system could be responsible for the curative properties of immunotherapy.
authors.affiliation: Centro de Ciências da Saúde, Departamento de Microbiologia e Parasitologia, Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Campus Universitário, Santa Maria, RS, Brazil.
authors.forename: Barbara Charlotte
authors.initials: BC
authors.lastname: Bach
authors.forename: Daniela Bitencourt Rosa
authors.initials: DB
authors.lastname: Leal
authors.forename: Jeandre Augusto dos Santos
authors.initials: JA
authors.lastname: Jaques
authors.forename: Viviane do Carmo Gonçalves
authors.initials: Vdo C
authors.lastname: Souza
authors.forename: Jader Betsch
authors.initials: JB
authors.lastname: Ruchel
authors.forename: Karine Bizzi
authors.initials: KB
authors.lastname: Schlemmer
authors.forename: Régis Adriel
authors.initials: RA
authors.lastname: Zanette
authors.forename: Pedro Abib
authors.initials: PA
authors.lastname: Hecktheuer
authors.forename: Patrique
authors.initials: P
authors.lastname: de Lima Pereira
authors.forename: Emerson André
authors.initials: EA
authors.lastname: Casali
authors.forename: Sydney Hartz
authors.initials: SH
authors.lastname: Alves
authors.forename: Janio Morais
authors.initials: JM
authors.lastname: Santurio
mesh_terms: D000225:Adenine / Q000378:metabolism; D000243:Adenosine Deaminase / Q000276:immunology / Q000378:metabolism*; D000255:Adenosine Triphosphate; D000818:Animals; D007113:Immunity, Innate; D007167:Immunotherapy; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D058968:Pythiosis / Q000188:drug therapy* / Q000276:immunology; D011775:Pythium / Q000276:immunology / Q000472:pathogenicity; D011817:Rabbits; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism*; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism*
chemical_list: D000255:Adenosine Triphosphate; D000243:Adenosine Deaminase; D000225:Adenine
keywords: Pythium insidiosum; adenosine; adenosine deaminase; lymphocytes; pythiosis