RESUMO
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.
Assuntos
Animais , Cães , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Doenças do Cão/imunologia , Imunidade Celular/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Anticorpos Antiprotozoários/imunologia , Proliferação de Células , Ensaio de Imunoadsorção Enzimática , Hipersensibilidade Tardia/imunologia , Interferon gama/sangue , Interferon gama/imunologia , Leishmania infantum , Leishmaniose Visceral/imunologia , Ativação Linfocitária/imunologia , Modelos Animais , Fatores de TempoRESUMO
Relatamos um caso de cisticercose sub-retiniana bilateral e neurocisticercose múltipla, descrevendo clínica e histopatologicamente a açäo da larvicida do praziquantel sobre os cisticercos sub-retinianos, - comparando-a com açäo larvicida da droga sobre os cisticercos do parênquina cerebral. Como a desintegraçäo por morte do parasito causa sérios danos intra-oculares, salientamos que o praziquantel näo está indicado na terapêutica da cisticercose intra-ocular