ABSTRACT
Los estudios en torno al papel patogénico del Schistosoma mansoni se enfocan en el daño hepático y la respuesta inmune en el hospedador definitivo, en contraste a la escasa información en relación a la patología intestinal. A tal fin, se evaluó el efecto del praziquantel en los receptores angiogenicos, citocinas inflamatorias y anti-inflamatorias en la esquitosomiasis intestinal murina. La respuesta inflamatoria granulomatosa intestinal se midió en secciones histológicas teñidas con H&E; la detección de TNF-α, IL-10, TGF-ß, el VEGF y sus receptores (FLK1 y FLT1) mediante inmunohistoquímica y ELISA, en suero e intestino de ratones BALB/c infectados con S. mansoni a las 8 (RI8S) y 20 semanas (RI20S), y ratones con 8 semanas de infección a los quince días de post-tratamiento, con praziquantel 40 µgr/gr (RPT). En RI8S se observaron granulomas pequeños (11304 µm2 en promedio), sin bordes definidos ni zonas marcadas dentro del granuloma, y granulomas de gran tamaño con bordes definidos (70650 µm2) sin zonas definidas dentro del granuloma, ambos con predominio de macrófagos y presencia de plasmocitos. En RI20S, los granulomas presentan una zona interna constituida por abundantes macrófagos y escasos plasmocitos, y una externa constituida solo por macrófagos (11985 µm2). En RPT no se apreciaron granulomas, solo algunos focos inflamatorios cercanos a la muscularis mucosae y las glándulas de Lieberkuhn. La Inmunolocalización en el intestino solo fue positiva en RPT para VEGF y sus receptores, TGP-ß e IL-10; Los resultados muestran una discreta respuesta en cuanto a tamaño del granuloma, celularidad y la expresión de citocinas a nivel intestinal.
The studies on the pathogenic role of the Schistosoma mansoni focus on the hepatic damage and the immune response of the final host, in constrast to the limited information regarding intestinal lesion. This work evaluates. Intestinal granulomatous inflammation was measured in histological sections the effect of praziquantel in the angiogenic receptors (FLK1 and FLT1), inflammation and inflammatory cytokines on the murine intestinal schistosomiasis stained with H&E; the detection of TNF-α, IL-10, TGF-ß, VEGF and its receptors was carried out by immunohistochemistry and ELISA, in serum and intestine sections of BALB/c mice infected with S. mansoni at 8 (RI8S) and 20 (RI20S) weeks post-infection, and mice infected for 8 weeks and evaluated 15 days post-treatment with praziquantel 40 µg/(RPT). In RI8S small granulomas (11.304 µm2 average), without sharp or marked edges within the granuloma; and large granulomas (70.650 µm2) with defined borders without defined zones within the granuloma, In both groups of mice macrophages predominated and plasma cells were present. In RI20S, granulomas have an inner zone composed by abundant macrophages and few plasma cells, and external zone constituted only by macrophages (11.985 µm2). In RPT, granulomas were not observed, only a few inflammatory foci nearby the muscularis mucosae and the Lieberkuhn glands. Localization of immune molecules in the intestine was only positive in RPT for VEGF, its receptors, TGF-ß and IL-10; the results show a discrete response over the granuloma size, cellularity and cytokine expression at intestinal level.
ABSTRACT
Schistosomiasis is a chronic parasitic disease caused by trematodes of the genus Schistosoma, endemic in tropical and subtropical regions. The hepatic pathology of this parasitic disease could develop complications, such as fibrosis and cirrhosis, which can be fatal. The Venezuelan endemic area is considered as one of low transmission, which complicates the detection of infected individuals and signals the importance of improving the sensitivity of immunodiagnostic methods. Using ELISA, an evaluation was conducted of IgM and IgG responses to soluble antigens of eggs and female worms (SEA and SFWA) and excretion-secretion products of eggs and female worms (ESPE and ESPAW) in infected Balb/c mice with different parasitic burden and infection times. A high positivity rate by IgM detection was observed for all antigen preparations in 7-week infections (100% by SEA, SFWA, ESPE, and ESPWA in high parasitic burden) as well as a reduction of this immunoglobulin in chronic infection. Positivity rate for IgG detection was higher in 20-week infections (100% by ESPE in low burden, 100% by SEA and ESPE in medium burden, and 100% by ESPE and ESPAW in high burden conditions). The potential use of combined or unique antigenic preparations associated with IgM or IgG for detection of active infection, regardless the parasitic burden, was demonstrated. Differences between immunoglobulin responses show its application for phase-specific diagnosis.
