ABSTRACT
To confirm that Beagle dogs are a good experimental model for Chagas disease, we evaluated hematological alterations during the acute and chronic phases in Beagle dogs infected with the Y, Berenice-78 (Be-78) and ABC strains of Trypanosomacruzi, correlating clinical signs with the parasitemia curve. We demonstrate that the acute phase of infection was marked by lethargy and loss of appetite. Simultaneously, we observed anemia, leukocytosis and lymphocytosis. Also,we describe hematological alterations and clinical signs that were positively correlated with the parasitemia during the experimental infection with the three strains of T.cruzi, and demonstrate that experimental infection of Beagle is a trustworthy model for Chagas disease.
Subject(s)
Chagas Disease/complications , Disease Models, Animal , Hematologic Diseases/etiology , Animals , DogsABSTRACT
To confirm that Beagle dogs are a good experimental model for Chagas disease, we evaluated hematological alterations during the acute and chronic phases in Beagle dogs infected with the Y, Berenice-78 (Be-78) and ABC strains of Trypanosoma cruzi, correlating clinical signs with the parasitemia curve. We demonstrate that the acute phase of infection was marked by lethargy and loss of appetite. Simultaneously, we observed anemia, leukocytosis and lymphocytosis. Also,we describe hematological alterations and clinical signs that were positively correlated with the parasitemia during the experimental infection with the three strains of T.cruzi, and demonstrate that experimental infection of Beagle is a trustworthy model for Chagas disease.
Para confirmar que cães Beagle são um bom modelo para doença de Chagas, foram avaliadas as alterações hematológicas durante as fases aguda e crônica em cães Beagle infectados com as cepas Y, Berenice-78 (Be-78) e ABC de Trypanosomacruzi, correlacionando os sinais clínicos com a curva de parasitemia. Foi demonstrado que a fase aguda da infecção foi marcada por letargia e perda de apetite. Simultaneamente, observou-se anemia, leucocitose e linfocitose. Ainda, foram descritas alterações hematológicas e sinais clínicos positivamente correlacionados com a parasitemia durante a infecção experimental com as três cepas de T.cruzi estudadas, demonstrando que a infecção em cães Beagle constitui um modelo fidedigno para a doença de Chagas.
Subject(s)
Animals , Dogs , Anemia , Chagas Disease , Leukocytosis , Lymphocytosis , Parasitemia , Trypanosoma cruzi/parasitology , Trypanosoma cruzi/pathogenicity , Disease Models, AnimalABSTRACT
Chemokines and chemokine receptors interaction have presented important role in leukocyte migration to specific immune reaction sites. Recently, it has been reported that chemokine receptors CXC (CXCR3) and CC (CCR5) were preferentially expressed on Th1 cells while CCR3 and CCR4 were preferentially expressed on Th2 cells. This study evaluated the mRNA expression of type 1 and type 2 chemokine and chemokine receptors in the cardiac tissue of Beagle dogs infected with distinct genetic groups of Trypanosoma cruzi (Y, Berenice-78 and ABC strains) during acute and chronic phases. To analyze the correlation between chemokine and chemokine receptors expression and the development of heart pathology, the chronic infected animals were divided into groups, according to the parasite strain and based on the degree of heart damage: cardiac and indeterminate form of Chagas disease. Our results indicated that cardiac type1/2 chemokines and their receptors were partially dependent on the genetic diversity of parasites as well as the polarization of clinical forms. Also, dogs presenting cardiac form showed lower heart tissue mRNA expression of CCL24 (type 2) and higher expression of CCL5, CCL4 and CXCR3 (type 1) when compared with those with indeterminate form of disease. Together, these data reinforce a close-relation between T. cruzi genetic population and the host specific type 1 immune response and, for the first time, we show the distribution of type 1/2 chemokines associated with the development of cardiac pathology using dogs, a well similar model to study human Chagas disease.
Subject(s)
Chagas Disease/genetics , Chagas Disease/immunology , Chemokines/genetics , Myocardium/immunology , Myocardium/pathology , Acute Disease , Animals , Base Sequence , Chagas Disease/pathology , Chemokines/classification , Chronic Disease , DNA Primers/genetics , Disease Models, Animal , Dogs , Gene Expression , Humans , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Chemokine/classification , Receptors, Chemokine/genetics , Species Specificity , Trypanosoma cruzi/classification , Trypanosoma cruzi/pathogenicityABSTRACT
An effective innate immune recognition of the intracellular protozoan parasite Trypanosoma cruzi is critical for host resistance against Chagas disease, a severe and chronic illness that affects millions of people in Latin America. In this study, we evaluated the participation of nucleotide-binding oligomerization domain (Nod)-like receptor proteins in host response to T. cruzi infection and found that Nod1-dependent, but not Nod2-dependent, responses are required for host resistance against infection. Bone marrow-derived macrophages from Nod1(-/-) mice showed an impaired induction of NF-kappaB-dependent products in response to infection and failed to restrict T. cruzi infection in presence of IFN-gamma. Despite normal cytokine production in the sera, Nod1(-/-) mice were highly susceptible to T. cruzi infection, in a similar manner to MyD88(-/-) and NO synthase 2(-/-) mice. These studies indicate that Nod1-dependent responses account for host resistance against T. cruzi infection by mechanisms independent of cytokine production.
