title: An experimental protocol for the establishment of dogs with long-term cellular immune reactions to Leishmania antigens.
abstract: Domestic dogs are considered to be the main reservoirs of zoonotic visceral leishmaniasis. In this work, we evaluated a protocol to induce Leishmania infantum/Leishmania chagasi-specific cellular and humoral immune responses in dogs, which consisted of two injections of Leishmania promastigote lysate followed by a subcutaneous inoculation of viable promastigotes. The primary objective was to establish a canine experimental model to provide positive controls for testing immune responses to Leishmania in laboratory conditions. After inoculation of viable promastigotes, specific proliferative responses of peripheral blood mononuclear cells (PBMCs) to either Leishmania lysate or recombinant proteins, the in vitro production of interferon-γ by antigen-stimulated PBMCs and a significant increase in circulating levels of anti-Leishmania antibodies were observed. The immunized dogs also displayed positive delayed-type hypersensitivity reactions to Leishmania crude antigens and to purified recombinant proteins. An important finding that supports the suitability of the dogs as positive controls is that they remained healthy for the entire observation period, i.e., more than seven years after infection. Following the Leishmania antigen lysate injections, the infection of dogs by the subcutaneous route appears to induce a sustained cellular immune response, leading to an asymptomatic infection. This provides a useful model for both the selection of immunogenic Leishmania antigens and for immunobiological studies on their possible immunoprotective activities.
authors.affiliation: Universidade Federal da Bahia, Salvador, BA, Brasil. marciat@ufba.br
authors.forename: Márcia Cristina Aquino
authors.initials: MC
authors.lastname: Teixeira
authors.forename: Geraldo Gileno de Sá
authors.initials: GG
authors.lastname: Oliveira
authors.forename: Patrícia Oliveira Meira
authors.initials: PO
authors.lastname: Santos
authors.forename: Thiago Campanharo
authors.initials: TC
authors.lastname: Bahiense
authors.forename: Virginia Maria Goes
authors.initials: VM
authors.lastname: da Silva
authors.forename: Márcio Silva
authors.initials: MS
authors.lastname: Rodrigues
authors.forename: Daniela Farias
authors.initials: DF
authors.lastname: Larangeira
authors.forename: Washington Luis Conrado
authors.initials: WL
authors.lastname: Dos-Santos
authors.forename: Lain Carlos
authors.initials: LC
authors.lastname: Pontes-de-Carvalho
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood* / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D049109:Cell Proliferation; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular / Q000276:immunology*; D007371:Interferon-gamma / Q000097:blood / Q000276:immunology; D018314:Leishmania infantum / Q000276:immunology* / Q000469:parasitology; D007898:Leishmaniasis, Visceral / Q000276:immunology / Q000662:veterinary*; D008213:Lymphocyte Activation / Q000276:immunology; D023421:Models, Animal; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007371:Interferon-gamma