title: Toll receptors type-2 and CR3 expression of canine monocytes and its correlation with immunohistochemistry and xenodiagnosis in visceral leishmaniasis.
abstract: The aim of the present study was to investigate TLR2 expression in peripheral blood monocytes from dogs naturally infected with Leishmania (Leishmania) infantum to determine whether it correlates with CD11b/CD18 (CR3) expression, and to evaluate the potential of dogs as sources of infection using phlebotomine xenodiagnosis. Forty eight dogs were serologically diagnosed with L. infantum infection by indirect immunofluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA). Parasitological exams from bone-marrow aspirates were positive by PCR analysis. All dogs were clinical defined as symptomatic. Ear skin tissue samples were obtained for immunohistochemistry (IHQ) analysis. The potential of these dogs as a source of infection using phlebotomine xenodiagnosis (XENO) was evaluated. Flow cytometry was carried out on peripheral blood mononuclear cells using superficial receptors including CD14, CD11b, TLR2 and MHCII. IHQ ear skin tissue parasite load and XENO where done where we found a strict correlation (r = 0.5373). Dogs with higher expression of MFI of CD11b inside CD14 monocytes were represented by dogs without parasite ear tissue load that were unable to infect phlebotomines (IHQ⁻/XENO⁻). Dogs with lower expression of MFI of CD11b inside CD14 monocytes were represented by dogs with parasite ear tissue load and able to infect phlebotomines (IHQ⁺/XENO⁺) (p = 0,0032). Comparable results were obtained for MFI of MHCII (p = 0.0054). In addition, considering the population frequency of CD11b⁺TLR2⁺ and CD11b⁺MHCII⁺, higher values were obtained from dogs with IHQ⁻/XENO⁻ than dogs with IHQ⁺/XENO⁺ (p = 0.01; p = 0.0048, respectively). These data, together with the TLR2 and NO assays results (CD11b⁺TLR2⁺ and NO with higher values for dogs with IHQ⁻/XENO⁻ than dogs with IHQ⁺/XENO⁺, led to the conclusion that IHQ⁻/XENO⁻ dogs are more resistant or could modulate the cellular immune response essential for Leishmania tissue clearance.
authors.affiliation: Departamento de Patologia Geral, Escola de Medicina, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Izabela Ferreira Gontijo de
authors.initials: IF
authors.lastname: Amorim
authors.forename: Sydnei Magno da
authors.initials: SM
authors.lastname: Silva
authors.forename: Maria Marta
authors.initials: MM
authors.lastname: Figueiredo
authors.forename: Eliane Perlatto
authors.initials: EP
authors.lastname: Moura
authors.forename: Rodrigo Soares de
authors.initials: RS
authors.lastname: Castro
authors.forename: Tatjana Keesen de Souza
authors.initials: TK
authors.lastname: Lima
authors.forename: Nelder de Figueiredo
authors.initials: Nde F
authors.lastname: Gontijo
authors.forename: Marilene Suzan Marques
authors.initials: MS
authors.lastname: Michalick
authors.forename: Kenneth John
authors.initials: KJ
authors.lastname: Gollob
authors.forename: Wagner Luiz
authors.initials: WL
authors.lastname: Tafuri
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis* / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D004285:Dogs; D005260:Female; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007700:Kinetics; D018314:Leishmania infantum; D007898:Leishmaniasis, Visceral / Q000175:diagnosis / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D016177:Macrophage-1 Antigen / Q000276:immunology*; D008297:Male; D009000:Monocytes / Q000276:immunology*; D009569:Nitric Oxide / Q000097:blood; D059208:Parasite Load; D010641:Phenotype; D012867:Skin / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D051196:Toll-Like Receptor 3 / Q000276:immunology*; D020525:Xenodiagnosis / Q000379:methods*
chemical_list: D016177:Macrophage-1 Antigen; D051196:Toll-Like Receptor 3; D009569:Nitric Oxide