Recently, the possibility to use salivary proteins from sand flies as components of a vaccine candidate has been demonstrated in dogs

Recently, the possibility to use salivary proteins from sand flies as components of a vaccine candidate has been demonstrated in dogs. days after infection we observed that 31,4% of dogs did not display detectable levels of anti-antibodies Sec-O-Glucosylhamaudol but all presented different numbers of parasites in the lymph nodes. Animals with a positive xenodiagnosis had at least 3,35105 parasites in their lymph nodes. An increase of IFN- and IL-10 levels was detected during infection. Twenty two percent of dogs developed symptoms of CVL during infection. Conclusion The infection model described here shows some degree of similarity when compared with naturally infected dogs opening new perspectives for the study of CVL using an experimental model that employs the combination of parasites and sand fly saliva both present during natural transmission. Introduction Canine visceral leishmaniasis (CVL) is caused by an intracellular protozoan parasite It is endemic in the Mediterranean Basin, South America and parts of Asia [1]. Domestic dogs are the main reservoirs and different control strategies, Sec-O-Glucosylhamaudol such as the use of insecticide impregnated collars or elimination of infected dogs have not been effective to decrease human incidence of VL [2]. Development of a vaccine for CVL has been identified as a research priority by WHO/TDR [3] and mathematical models have highlighted canine vaccination as the potentially most practical and effective means of Rabbit polyclonal to DARPP-32.DARPP-32 a member of the protein phosphatase inhibitor 1 family.A dopamine-and cyclic AMP-regulated neuronal phosphoprotein. impacting disease control in humans [4]. Also, since dogs present many symptoms observed in humans, with a long period of asymptomatic infection followed by wasting, anaemia, enlarged lymph nodes, and fever, the canine model is important to study VL pathogenesis and for development of pre clinical trials related to therapy. Although an experimental canine model for VL is highly desirable previous attempts to infect dogs have used the inoculation of a high number of parasites intravenously that in some occasions did not result in disease development [5], [6], [7]. parasites are transmitted by female sand flies that co-inject parasites and different products from the vector, including saliva, in the hosts skin. Saliva of sand flies and of other blood feeding arthropods contains potent pharmacological components to facilitate the blood meal. Salivary proteins also play an important role during pathogen transmission as co-inoculation of sand fly saliva with the parasite exacerbates parasite infectivity [8], [9], [10], [11], [12], [13], [14], [15]. Although the use of vector saliva and Leishmania in different experimental models such as mice and hamsters have been employed, few studies used this experimental approach in dogs and results are divergent [16], [17] Therefore, the establishment of an experimental model of infection in dogs, using parasites and saliva, could be very important in the context of natural transmission. Such model would therefore be useful to test new approaches of vaccines against CVL and our present research line is to test potential vaccine candidates employing salivary proteins from the vector. Herein, we report that the use of stationary phase promastigotes of and salivary gland homogenate (SGH) of results in disease development in 100% of the dogs with different degrees of disease severity. Besides Sec-O-Glucosylhamaudol that, comparing experimentally and naturally infected dogs we noticed that clinical symptoms as Sec-O-Glucosylhamaudol well as inflammatory responses were very similar suggesting that the currently developed model is appropriate for our future objectives, which will test vaccine candidates using salivary proteins. Materials and Methods Animals In this study, we used 35 experimentally infected and eight naturally infected dogs. We purchased thirty-five beagles of both genders (eight to ten months old), in a non-endemic area from Brazil, from a local breeder (Canil Tads Henriques, Colombo, Paran State, Brazil). All procedures performed in experimentally infected dogs were approved and permitted by the Ethical Committee for Animals Use (CEUA) from Centro de Pesquisa Gon?alo Moniz/Bahia – FIOCRUZ/Ba, under the number 010/2009. The study was supported by the Financial Agency from Estado.