ABSTRACT
Complement-depleted and -non-depleted BALB/c mice were inoculated with Leishmania (Leishmania) amazonensis promastigotes into the hind footpad to study the role of the complement system in cutaneous leishmaniasis. Total serum complement activity was measured by hemolytic assay and C3 fragment deposit at the inoculation site was determined by direct immunofluorescence in the early period of infection, i.e., at 3, 24, 48 h and 7 days post-infection. The inflammatory reaction and the parasite burden were evaluated in the skin lesion at 7 and 30 days post-infection. Total serum complement activity decreased in the early phase of infection, from 3 to 24 h, in non-depleted mice compared to non-infected and non-depleted mice. C3 fragment deposit at the site of parasite inoculation was present throughout the period of infection in non-depleted mice. In contrast, no C3 fragment deposit was observed at the inoculation site in complement-depleted mice. Complement-depleted mice showed a significant decrease in the inflammatory response and a significant increase in the number of parasites (70.0 ± 5.3 vs 5.3 ± 1.5) at 7 days of infection (P < 0.05). A higher number of parasites were also present at 30 days of infection at the inoculation site of complement-depleted mice (78.5 ± 24.9 vs 6.3 ± 5.7). These experiments indicate that complement has an important role at the beginning of experimental cutaneous leishmaniasis caused by L. (L.) amazonensis by controlling the number of parasites in the lesion.
Subject(s)
Animals , Male , Mice , Complement System Proteins , Leishmania , Leishmaniasis, Cutaneous , Complement C3 , Complement Hemolytic Activity Assay , Fluorescent Antibody Technique, Direct , Leishmaniasis, Cutaneous , Lymphocyte Depletion , Mice, Inbred BALB CABSTRACT
Estudamos a susceptibilidade a Leishmania (Viannia) panamensis em linhagens de camundongos BALB/c, DBA/2J, CBA/HJ e C57BL/6. Os camundongos da linhagem C57BL/6 eram resistentes, apresentando lesoes autolimitantes na pata. Os das linhagens BALB/c e DBA/2J eram suscetiveis, apresentando edema na pata, evidente aos 20 dias pos-infeccao que progrediu para uma lesao tipo tumoral nas fases tardias. Os animais da linhagem CBA/HJ apresentaram resistencia intermediaria. Em contraste a outros modelos de leishmaniose cutanea murina, a lesao nos camundongos infectados pela L. (V.) panamensis mostrou ser restrita ao local de inoculacao na pele. Estudamos tambem o desenvolvimento de resposta celular e anticorpos anti-Leishmania nas linhagens BALB/c e C57BL/6. A resposta proliferativa de celulas do linfonodo a antigenos de L. (V.) panamensis foi bifasica em ambas as linhagens...
Subject(s)
Animals , Male , Rats , Leishmaniasis/immunology , Culture Media , Leishmaniasis/parasitology , Leishmania/isolation & purification , Sensitivity and SpecificityABSTRACT
In American man can be infected with two trypanosomes: Trypanosoma cruzi, the etiological agent of Chagas' disease and Trypanosoma rangeli, a suspected nonpathogenic parasite. In this communication are presented 4 methods in order to improve the current knowledge about the specific identification of these parasites. Using the SDS-PAGE technique it was possible to differentiate between T. rangeli. and T. cruzi based in at less 4 protein bands with a relative molecular weights of 93, 77-73, 63 and 54-52 KDa. These polypeptides were found only in T. rangeli electrophoretic profiles. An ELISA test showed that the antigenic composition found in the enzyme cisteine proteinase (cruzipain) is specific for T. cruzi epimastigotes. Antigenic analysis by Western blot assay, proved that T. rangeli and not T. cruzi present antigenic bands with a Mr of 142, 63, 54, 51, 49, 43, 39 and 24 KDa. Finally, using the Southern blot procedure, it was confirmed that SAPA, a DNA sequence originally identified in the T. cruzi, genome, is absent in T. rangeli nuclear DNA. These initial observations revealed that it is possible to identify both parasites using the described methods, however further works are required to clarify the biochemical, immunological and molecular relationship between T. rangeli and T. cruzi
Subject(s)
Animals , Trypanosoma/isolation & purification , Enzyme-Linked Immunosorbent Assay , Antigens, Protozoan/analysis , DNA, Protozoan/analysis , Electrophoresis, Gel, Two-Dimensional , Evaluation Study , Blotting, Southern , Trypanosoma/classification , Trypanosoma/genetics , Trypanosoma/immunology , Blotting, WesternABSTRACT
Se evalúan los niveles del receptor soluble de interleucina-2 (sIL-2R) en sueros de pacientes que presentaban la forma clínica aguda o crónica de la Enfermedad de Chagas. El valor promedio de sIL-2R observado en pacientes en fase aguda fue de 3282+-1715 u/ml., en pacientes en fase crónica fué de 511+-207 U/ml. y en sujetos controles fué de 366+-108 U/ml.. Al correlacionar los datos obtenidos con los niveles de anti-cuerpos específicos en estos pacientes observamos que títulos altos de sIL-2R (1000 U/ml. Se asociaron a la presencia de anticuerpos anti T. cruzi en infecciones recientes ó agudas. Esta correlación no fué estrictamente cuantitativa ó directamente proporcional. En pacientes crónicos con niveles elevados de anticuerpos específicos anti T. cruzi no mostraron correlación con la presencia de niveles séricos de sIL-2R, los cuales pueden ser bajos en casos crónicos de largo seguimiento. Consideramos que la presencia de niveles altos de receptor soluble de interleucina-2 se relaciona con la actividad del parásito y su interacción con el huésped. Finalmente, se discute la posibilidad del uso del sIL-2R como marcador de fase aguda y su importancia como indicador de riesgo de enfermedad
Subject(s)
Interleukin-2 , Chagas Disease , Leishmaniasis, VisceralABSTRACT
Se evalúan los niveles del Receptor soluble de interleucina-2 (sIL-2R) en sueros de pacientes que presentaban la forma clínica aguda o crónica de la Enfermedad de Chagas. El valor promedio de sIL-2R observado en pacientes en fase aguda fue de 511+-207 U/ml. y en sujetos controles fue de 366+-108 U/ml. Al correlacionar los datos obtenidos con los niveles de anticuerpos específicos en estos pacientes observamos que títulos altos de sIL-2R (1000 U/ml) se asociaron a la presencia de anticuerpos específicos anti-T. cruzi en infecciones recientes ó agudas. Esta correlación no fué estrictamente cuantitativa o directamente proporcional. En pacientes crónicos con niveles elevados de anticuerpos específicos anti-T. cruzi no mostraron correlación con la presencia de niveles séricos de sIL-2R, los cuales pueden ser bajos en casos crónicos de largo seguimiento. Consideramos que la presencia de niveles altos del receptor soluble de interleucina-2 se relaciona con la actividad del parásito y su interacción con el huésped. Finalmente, se discute la posibIlidad del uso del sIL-2R como marcador de fase aguda y su importancia como indicador de riesgo de enfermedad