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Canine humoral immune responses elicited in oral infections with Neospora caninum
Abstracts / Veterinary Immunology and Immunopathology 128 (2009) 211–347
results herein obtained indicate that dogs present a protracted acute phase, with oocyst shedding being correlated to a drop in CD4+ and CD8+ T cell blood levels, and low MHC class II expression in the lymph nodes. Cytokine mRNA profile revealed that dogs present high modulatory cytokine expression till the 60th dpi, followed by a sharp increase in inflammatory cytokines, as IFN(. Based on these results, we may conclude that N. caninum modulates the dog cellular immune response during its sexual cycle. doi:10.1016/j.vetimm.2008.10.192 Canine humoral immune responses elicited in oral infections with Neospora caninum Mineo 1,∗ ,
Tiago Wilson Patriarca gela Zacarias Machado 1
Michael J.
Day 2 ,
Rosan-
1 Department of Veterinary Pathology, FCAV/UNESP, Jaboticabal, SP, Brazil 2 Division of Veterinary Pathology, Infection and Immunity, School of Clinical Veterinary Science, University of Bristol, Bristol, UK Keywords: Neospora caninum; Antibody kinetics; Delayed seroconversion; Ontogeny of immune system
Species: CanineNeospora caninum is an Apicomplexan parasite firstly described as cause of encephalomyelitis in puppies serologically negative to Toxoplasma gondii. Previous reports on the parasite’s definitive host indicate a late IgG antibody response and that clinical disease is difficult to be induced. The aim of this study was to investigate canine humoral immunity during N. caninum oral infection. For that purpose, clinically healthy dogs, serologically negative for N. caninum and correlated parasites were selected and divided into three main groups: inoculated adult dogs, inoculated puppies, and control group. Inoculated animals were submitted to oral intake of 500 g/day of fresh bovine meat, nervous tissues and offal, for three consecutive days. Blood samples were collected by vein punction at close time intervals to observe total and specific antibody kinetics for 250 days post-infection (dpi). Total antibody production was followed up by commercial ELISA kits and specific immunoenzimatic assays were standardized for IgM, IgA, IgE, IgG and subclasses (IgG1, IgG2, IgG3 and IgG4). Additionally, detection of specific IgM and IgG were realized through indirect immunofluorescence antibody tests (IFAT), and IgG antigen recognition profile was visualized through one-dimensional western blotting (WB). The results obtained indicate that dogs present a low specific antibody production during acute phase of infection, showing an unstable seroconversion pattern, with only IgG1 and IgG3 being detected in adult dogs and puppies, respectively, between the second and third months of infection. Corroborating with those results, WB analysis demonstrated absence of antigen recognition within the first 30 dpi in almost all animals. IFAT showed similar pattern, with late IgM and IgG seroconversion. During the experimental period, five IgG2 and IgE peaks were observed in an associated manner, and were also correlated
301
to lower Th1 type antibody production. Analyzing total antibody production, it could be observed that younger animals present a crescent curve in all analyzed antibodies, whereas adult animals demonstrate stable serum antibody concentrations. After 60 dpi, specific antibody levels showed an increment, especially IgG1 and IgG4 in puppies. Taken together, we may conclude that antibody production is initially impaired in dogs after oral intake of parasite contaminated tissues, and that Th1 and Th2 profile antibodies are present concomitantly after infection. Moreover, the higher susceptibility of puppies to N. caninum may be attributed to the ontogeny of the immune system. doi:10.1016/j.vetimm.2008.10.193 Frequencies of anti-Trypanosoma cruzi antibodies in dogs from southern of Rio Grande do Sul State Charlene N.S. Trindade, Fabio P.L. Leite ∗ , Nara R. Farias Departamento de Microbiologia e Parasitologia-UFPel, Brazil Keywords: Trypanosoma cruzi; Dogs; Antibodies E-mail address: fabio [email protected] (F.P.L. Leite). Species: Canine Chagas’ disease is a trypanosomiasis found in the Americas whose etiological agent is Trypanosoma cruzi. The different epidemiological and clinical manifestations of the infection and the mechanisms and/or factors that determine the development of morbidity are still unclear. Several important points remain to be clarified with regard to the natural history of Chagas’ disease. One of these is the role of domestic’s animals, principally the dog, as potential element for the transmission and maintenance of the parasite in the human population. The prevalence of infection among dogs from endemic zones, the close relationship between human and the identity of parasites infecting humans and dogs, suggest that this disease possibly involves these animals as reservoirs. The aim of this study was to characterize the frequency of antibodies antiT. cruzi in a dog population from a Chagas’ disease in an endemic area located at the south of Rio Grande do Sul state. Serum from 99 dogs was collected, in rural and urban area, and analyzed by a commercial indirect immunofluorescent test (IFI) using an anti-dog IgG labeled with FITC. The sera were diluted 1:32 and analyzed microscopically in duplicate. From the 99 sera studied 90.8% (89) were positive to T. cruzi. The majority of the positive dogs to T. cruzi live in houses with people, independently, of rural or urban area. These results suggest that the dog might play an important role in the transmission and/or maintenance of T. cruzi in endemic areas in the south of Brazil. This work is relevant to the question whether dogs act as reservoirs, disseminating the infection or are just susceptible to T. cruzi without having a major role in the spread of the disease. Thus, better diagnostics and epidemiological survey should be done in domestic’s animals in order to prevent this disease. This observations suggest that population in this areas should be alerted as well the
results herein obtained indicate that dogs present a protracted acute phase, with oocyst shedding being correlated to a drop in CD4+ and CD8+ T cell blood levels, and low MHC class II expression in the lymph nodes. Cytokine mRNA profile revealed that dogs present high modulatory cytokine expression till the 60th dpi, followed by a sharp increase in inflammatory cytokines, as IFN(. Based on these results, we may conclude that N. caninum modulates the dog cellular immune response during its sexual cycle. doi:10.1016/j.vetimm.2008.10.192 Canine humoral immune responses elicited in oral infections with Neospora caninum Mineo 1,∗ ,
Tiago Wilson Patriarca gela Zacarias Machado 1
Michael J.
Day 2 ,
Rosan-
1 Department of Veterinary Pathology, FCAV/UNESP, Jaboticabal, SP, Brazil 2 Division of Veterinary Pathology, Infection and Immunity, School of Clinical Veterinary Science, University of Bristol, Bristol, UK Keywords: Neospora caninum; Antibody kinetics; Delayed seroconversion; Ontogeny of immune system
Species: CanineNeospora caninum is an Apicomplexan parasite firstly described as cause of encephalomyelitis in puppies serologically negative to Toxoplasma gondii. Previous reports on the parasite’s definitive host indicate a late IgG antibody response and that clinical disease is difficult to be induced. The aim of this study was to investigate canine humoral immunity during N. caninum oral infection. For that purpose, clinically healthy dogs, serologically negative for N. caninum and correlated parasites were selected and divided into three main groups: inoculated adult dogs, inoculated puppies, and control group. Inoculated animals were submitted to oral intake of 500 g/day of fresh bovine meat, nervous tissues and offal, for three consecutive days. Blood samples were collected by vein punction at close time intervals to observe total and specific antibody kinetics for 250 days post-infection (dpi). Total antibody production was followed up by commercial ELISA kits and specific immunoenzimatic assays were standardized for IgM, IgA, IgE, IgG and subclasses (IgG1, IgG2, IgG3 and IgG4). Additionally, detection of specific IgM and IgG were realized through indirect immunofluorescence antibody tests (IFAT), and IgG antigen recognition profile was visualized through one-dimensional western blotting (WB). The results obtained indicate that dogs present a low specific antibody production during acute phase of infection, showing an unstable seroconversion pattern, with only IgG1 and IgG3 being detected in adult dogs and puppies, respectively, between the second and third months of infection. Corroborating with those results, WB analysis demonstrated absence of antigen recognition within the first 30 dpi in almost all animals. IFAT showed similar pattern, with late IgM and IgG seroconversion. During the experimental period, five IgG2 and IgE peaks were observed in an associated manner, and were also correlated
301
to lower Th1 type antibody production. Analyzing total antibody production, it could be observed that younger animals present a crescent curve in all analyzed antibodies, whereas adult animals demonstrate stable serum antibody concentrations. After 60 dpi, specific antibody levels showed an increment, especially IgG1 and IgG4 in puppies. Taken together, we may conclude that antibody production is initially impaired in dogs after oral intake of parasite contaminated tissues, and that Th1 and Th2 profile antibodies are present concomitantly after infection. Moreover, the higher susceptibility of puppies to N. caninum may be attributed to the ontogeny of the immune system. doi:10.1016/j.vetimm.2008.10.193 Frequencies of anti-Trypanosoma cruzi antibodies in dogs from southern of Rio Grande do Sul State Charlene N.S. Trindade, Fabio P.L. Leite ∗ , Nara R. Farias Departamento de Microbiologia e Parasitologia-UFPel, Brazil Keywords: Trypanosoma cruzi; Dogs; Antibodies E-mail address: fabio [email protected] (F.P.L. Leite). Species: Canine Chagas’ disease is a trypanosomiasis found in the Americas whose etiological agent is Trypanosoma cruzi. The different epidemiological and clinical manifestations of the infection and the mechanisms and/or factors that determine the development of morbidity are still unclear. Several important points remain to be clarified with regard to the natural history of Chagas’ disease. One of these is the role of domestic’s animals, principally the dog, as potential element for the transmission and maintenance of the parasite in the human population. The prevalence of infection among dogs from endemic zones, the close relationship between human and the identity of parasites infecting humans and dogs, suggest that this disease possibly involves these animals as reservoirs. The aim of this study was to characterize the frequency of antibodies antiT. cruzi in a dog population from a Chagas’ disease in an endemic area located at the south of Rio Grande do Sul state. Serum from 99 dogs was collected, in rural and urban area, and analyzed by a commercial indirect immunofluorescent test (IFI) using an anti-dog IgG labeled with FITC. The sera were diluted 1:32 and analyzed microscopically in duplicate. From the 99 sera studied 90.8% (89) were positive to T. cruzi. The majority of the positive dogs to T. cruzi live in houses with people, independently, of rural or urban area. These results suggest that the dog might play an important role in the transmission and/or maintenance of T. cruzi in endemic areas in the south of Brazil. This work is relevant to the question whether dogs act as reservoirs, disseminating the infection or are just susceptible to T. cruzi without having a major role in the spread of the disease. Thus, better diagnostics and epidemiological survey should be done in domestic’s animals in order to prevent this disease. This observations suggest that population in this areas should be alerted as well the