RESUMO
The association between the nutritional state of mongrel dogs naturally infected with Trypanosoma cruzi and their infectivity to Triatoma infestans bugs and immune response to Trypanosoma cruzi were studied in the rural village of Amamá, northwestern Argentina. All of the 97 evaluated dogs were classified into one of three categories of external clinical aspect (ECA) based on the degree of muscle development, external evidence of bone structures, state of the hair of the coat, existence of fatty deposits, and facial expression. ECA was significantly associated with two nutritional indicators, hematocrit and skin-fold thickness, but not with total serum proteins. For all dogs, hematocrit was significantly correlated with skin-fold thickness. The 2-year survival probability decreased significantly from 60.7% for dogs with good ECA to 45.9% and 31.2% for those with regular and bad ECA, respectively. The age-adjusted relative odds of infection for Triatoma infestans xeno-diagnosis nymphs that fed once on a dog seroreactive for Trypanosoma cruzi decreased significantly as ECA improved, when tested by multiple logistic regression analysis. A delayed hypersensitivity reaction was observed in all of the seroreactive dogs with good ECA but only in 45-50% of those with regular or bad ECA. Dogs with bad ECA had a 2.6 and 6.3 times greater probability of infecting triatomines after a single full blood meal than dogs with regular or good ECA, respectively. Our study shows that the reservoir competence of dogs for Trypanosoma cruzi was associated with ECA, which is a surrogate and valid index of nutritional state.
Assuntos
Doença de Chagas/veterinária , Doenças do Cão/parasitologia , Ectoparasitoses/veterinária , Distúrbios Nutricionais/veterinária , Animais , Anticorpos Antiprotozoários/sangue , Argentina/epidemiologia , Proteínas Sanguíneas/análise , Doença de Chagas/sangue , Doença de Chagas/complicações , Doença de Chagas/mortalidade , Doença de Chagas/transmissão , Estudos Transversais , Doenças do Cão/mortalidade , Cães , Ectoparasitoses/complicações , Ectoparasitoses/epidemiologia , Ectoparasitoses/transmissão , Feminino , Hematócrito/veterinária , Insetos Vetores/parasitologia , Masculino , Distúrbios Nutricionais/complicações , Distúrbios Nutricionais/mortalidade , Distúrbios Nutricionais/parasitologia , Estado Nutricional , Dobras Cutâneas , Taxa de Sobrevida , Triatoma/parasitologia , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/patogenicidadeRESUMO
Subcellular fractions of T. cruzi epimastigotes (Epi) were studied for their capability to induce protective or aggressive effects in animals. The flagellar fraction (F) showed the best immunoprotective properties without tissular aggression. Monoclonal antibodies were raised against F. Two of them, FCH-F8-1 and 4, were able to neutralize the infectivity of bloodstream forms, to mediate lysis by complement of cell culture derived[trypomastigotes (Tripo) and to recognize the surface of Tripo and Epi. FCH-F8-1 reacted with a 85 kDa protein from Tripo (assayed by immunoprecipitation) and with peptides of 43 kDa on Epi and Tripo (tested by immunoblotting). FCH-F8-4 recognized several proteins ranging from 50 to 150 kDa on Epi and two molecules of 15 and 48 kDa on Tripo. Mice immunized with antigens purified by affinity chromatography by using FCH-F8-4 were protected against the infection. Several recombinant clones were detected on a cDNA lambda gt11 expression library constructed from T. cruzi Epi (Tulahuén strain): three with FCH-F8-4 and two with FCH-F8-1. One clone recognized by each monoclonal antibody was studied gamma (FCH-F8-1) 1 and gamma (FCH-F8-4) 1. Both inserts were of 150 base pairs each; they detected a 3.5 and 5.0 kilobases Epi mRNA, respectively. Both inserts were sequenced, and the amino acid sequences were inferred. gamma (FCH-F8-4) 1 codified for a 19 aa peptide, PAFLGCSSRFSGSFSGVEP, and gamma (FCH-F8-1) 1 for a 29 aa peptide EFLERGRISCORHSYTSYTSCSDEHNVTPFC. The whole 19 aa peptide was synthesized. This peptide (SP4) inhibited the ELISA reactivity against the parasite of chronically infected and F immunized mouse sera.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Anticorpos Monoclonais , Antígenos de Protozoários/imunologia , Doença de Chagas/imunologia , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Animais , Antígenos de Protozoários/isolamento & purificação , Citotoxicidade Imunológica , Camundongos , Camundongos Endogâmicos BALB C , Fragmentos de Peptídeos/imunologia , Mapeamento de PeptídeosRESUMO
Subcellular fractions of T. cruzi epimastigotes (Epi) were studied for their capability to induce protective or aggressive effects in animals. The flagellar fraction (F) showed the best immunoprotective properties without tissular aggression. Monoclonal antibodies were raised against F. Two of them, FCH-F8-1 and 4, were able to neutralize the infectivity of bloodstream forms, to mediate lysis by complement of cell culture derived[trypomastigotes (Tripo) and to recognize the surface of Tripo and Epi. FCH-F8-1 reacted with a 85 kDa protein from Tripo (assayed by immunoprecipitation) and with peptides of 43 kDa on Epi and Tripo (tested by immunoblotting). FCH-F8-4 recognized several proteins ranging from 50 to 150 kDa on Epi and two molecules of 15 and 48 kDa on Tripo. Mice immunized with antigens purified by affinity chromatography by using FCH-F8-4 were protected against the infection. Several recombinant clones were detected on a cDNA lambda gt11 expression library constructed from T. cruzi Epi (Tulahuén strain): three with FCH-F8-4 and two with FCH-F8-1. One clone recognized by each monoclonal antibody was studied gamma (FCH-F8-1) 1 and gamma (FCH-F8-4) 1. Both inserts were of 150 base pairs each; they detected a 3.5 and 5.0 kilobases Epi mRNA, respectively. Both inserts were sequenced, and the amino acid sequences were inferred. gamma (FCH-F8-4) 1 codified for a 19 aa peptide, PAFLGCSSRFSGSFSGVEP, and gamma (FCH-F8-1) 1 for a 29 aa peptide EFLERGRISCORHSYTSYTSCSDEHNVTPFC. The whole 19 aa peptide was synthesized. This peptide (SP4) inhibited the ELISA reactivity against the parasite of chronically infected and F immunized mouse sera.(ABSTRACT TRUNCATED AT 250 WORDS)
RESUMO
Female adult rats fed with a protein-free normocaloric diet were antigenically stimulated with 1.3 x 10(-9) sheep red blood cells. Lymphoid spleen population, spleen plaque forming cells and serum haemolysins were measured in experimental as well as in control animals fed with a normal (18% protein) diet. A persistent diminution, proportionally related to the period of protein deprivation, of all parameters studied was observed; the fall was more prominent for haemolysin titre which became undetectable after 15 days of protein-free diet. Also, animals exposed to the aproteic diet during 15 days were afterwards returned to a normal diet and maintained on it during variable periods of time. A rapid restoration of the humoral response capacity, up to 60% of normal after 4 days of protein intake, and completely normal, following 6 days of refeeding, was observed. These findings suggest that protein starvation influences the production of circulating antibodies more than the antibody-forming cells. The aproteic induced impairment involved in the immunoglobulin synthesis does not appear to be irreversible, at least during the dieting period explored in the present study.
Assuntos
Formação de Anticorpos , Linfócitos B/imunologia , Deficiência de Proteína/imunologia , Animais , Dieta , Proteínas Alimentares/administração & dosagem , Feminino , Tamanho do Órgão , Ratos , Baço/anatomia & histologia , Timo/anatomia & histologia , Ensaio de Placa ViralRESUMO
Female adult rats fed with a protein-free normocaloric diet were antigenically stimulated with 1.3 x 10(-9) sheep red blood cells. Lymphoid spleen population, spleen plaque forming cells and serum haemolysins were measured in experimental as well as in control animals fed with a normal (18
protein) diet. A persistent diminution, proportionally related to the period of protein deprivation, of all parameters studied was observed; the fall was more prominent for haemolysin titre which became undetectable after 15 days of protein-free diet. Also, animals exposed to the aproteic diet during 15 days were afterwards returned to a normal diet and maintained on it during variable periods of time. A rapid restoration of the humoral response capacity, up to 60
of normal after 4 days of protein intake, and completely normal, following 6 days of refeeding, was observed. These findings suggest that protein starvation influences the production of circulating antibodies more than the antibody-forming cells. The aproteic induced impairment involved in the immunoglobulin synthesis does not appear to be irreversible, at least during the dieting period explored in the present study.
RESUMO
Female adult rats fed with a protein-free normocaloric diet were antigenically stimulated with 1.3 x 10(-9) sheep red blood cells. Lymphoid spleen population, spleen plaque forming cells and serum haemolysins were measured in experimental as well as in control animals fed with a normal (18
protein) diet. A persistent diminution, proportionally related to the period of protein deprivation, of all parameters studied was observed; the fall was more prominent for haemolysin titre which became undetectable after 15 days of protein-free diet. Also, animals exposed to the aproteic diet during 15 days were afterwards returned to a normal diet and maintained on it during variable periods of time. A rapid restoration of the humoral response capacity, up to 60
of normal after 4 days of protein intake, and completely normal, following 6 days of refeeding, was observed. These findings suggest that protein starvation influences the production of circulating antibodies more than the antibody-forming cells. The aproteic induced impairment involved in the immunoglobulin synthesis does not appear to be irreversible, at least during the dieting period explored in the present study.