<it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement

<p>Abstract</p> <p>Background</p> <p>Human amoebiasis is caused by the parasitic protozoan <it>Entamoeba histolytica </it>that lives in the large intestine of hosts, where can produce asymptomatic colonization until severe invasive infections with blood diar...

Full description

Bibliographic Details
Main Authors: Gomes Maria A, Ferreira Anderson J, Nunes Álvaro C, Costa Cássia AX, Caliari Marcelo V
Format: Article
Language:English
Published: BMC 2010-03-01
Series:Parasites & Vectors
Online Access:http://www.parasitesandvectors.com/content/3/1/23
id doaj-1a23df994b3847869e74c4b31ada88c1
record_format Article
spelling doaj-1a23df994b3847869e74c4b31ada88c12020-11-25T02:30:40ZengBMCParasites & Vectors1756-33052010-03-01312310.1186/1756-3305-3-23<it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complementGomes Maria AFerreira Anderson JNunes Álvaro CCosta Cássia AXCaliari Marcelo V<p>Abstract</p> <p>Background</p> <p>Human amoebiasis is caused by the parasitic protozoan <it>Entamoeba histolytica </it>that lives in the large intestine of hosts, where can produce asymptomatic colonization until severe invasive infections with blood diarrhea and spreading to other organs. The amoebic abscesses in liver are the most frequent form of amoebiasis outside intestine and still there are doubts about the pathogenic mechanisms involved in their formation. In this study we evaluated the <it>in situ </it>binding of antibodies, C3 and C9 complement components on trophozoites, in livers of hamsters infected with <it>E. histolytica</it> or <it>E. dispar</it>. These parameters were correlated with the extension of the hepatic lesions observed in these animals and with trophozoites survivor.</p> <p>Methods</p> <p>Hamsters were inoculated intra-hepatically with 100,000 trophozoites of <it>E. histolytica </it>or <it>E. dispar </it>strain and necropsied 12, 24, 48, 72, 144 and 192 h after inoculation. Antibodies, C3 and C9 binding to trophozoites were detected by immunohistochemistry. The estimation of the necrosis area and the number of labeled trophozoites was performed using digital morphometry analysis.</p> <p>Results</p> <p>In the liver sections of animals inoculated with the amoebas, the binding of antibodies to <it>E. histolytica </it>trophozoites was significantly lower than to <it>E. dispar </it>trophozoites. Trophozoites of <it>E. dispar </it>were also more frequently vacuolated and high labeled cellular debris observed in the lesions. Positive diffuse reaction to C3 complement component was more intense in livers of animals inoculated with <it>E. histolytica </it>after 24 and 72 h of infection. C3<sup>(+) </sup>and C9<sup>(+) </sup>trophozoites were detected in the vascular lumen, granulomas and inside and in the border of necrotic areas of both infected group animals. C3<sup>(+) </sup>and C9<sup>(+) </sup>trophozoite debris immunostaining was higher in livers of <it>E. dispar </it>than in livers of <it>E. histolytica</it>. A positive correlation between necrotic areas and number of C9<sup>(+) </sup>trophozoites was observed in animals inoculated with <it>E. dispar</it>.</p> <p>Conclusion</p> <p>Morphological and immunohistochemical results suggest that antibodies and complement are able to bind and destroy some trophozoites in the liver of experimentally infected hamsters, perhaps selecting the more resistant parasites which are responsible by progression of amoebic abscesses. The findings indicate that <it>E. histolytica </it>possesses an enhanced ability <it>in vivo </it>to evade the immune responses compared to <it>E. dispar</it>, although it also causes experimental hepatic lesions.</p> http://www.parasitesandvectors.com/content/3/1/23
collection DOAJ
language English
format Article
sources DOAJ
author Gomes Maria A
Ferreira Anderson J
Nunes Álvaro C
Costa Cássia AX
Caliari Marcelo V
spellingShingle Gomes Maria A
Ferreira Anderson J
Nunes Álvaro C
Costa Cássia AX
Caliari Marcelo V
<it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
Parasites & Vectors
author_facet Gomes Maria A
Ferreira Anderson J
Nunes Álvaro C
Costa Cássia AX
Caliari Marcelo V
author_sort Gomes Maria A
title <it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
title_short <it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
title_full <it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
title_fullStr <it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
title_full_unstemmed <it>Entamoeba histolytica </it>and <it>E. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
title_sort <it>entamoeba histolytica </it>and <it>e. dispar </it>trophozoites in the liver of hamsters: in vivo binding of antibodies and complement
publisher BMC
series Parasites & Vectors
issn 1756-3305
publishDate 2010-03-01
description <p>Abstract</p> <p>Background</p> <p>Human amoebiasis is caused by the parasitic protozoan <it>Entamoeba histolytica </it>that lives in the large intestine of hosts, where can produce asymptomatic colonization until severe invasive infections with blood diarrhea and spreading to other organs. The amoebic abscesses in liver are the most frequent form of amoebiasis outside intestine and still there are doubts about the pathogenic mechanisms involved in their formation. In this study we evaluated the <it>in situ </it>binding of antibodies, C3 and C9 complement components on trophozoites, in livers of hamsters infected with <it>E. histolytica</it> or <it>E. dispar</it>. These parameters were correlated with the extension of the hepatic lesions observed in these animals and with trophozoites survivor.</p> <p>Methods</p> <p>Hamsters were inoculated intra-hepatically with 100,000 trophozoites of <it>E. histolytica </it>or <it>E. dispar </it>strain and necropsied 12, 24, 48, 72, 144 and 192 h after inoculation. Antibodies, C3 and C9 binding to trophozoites were detected by immunohistochemistry. The estimation of the necrosis area and the number of labeled trophozoites was performed using digital morphometry analysis.</p> <p>Results</p> <p>In the liver sections of animals inoculated with the amoebas, the binding of antibodies to <it>E. histolytica </it>trophozoites was significantly lower than to <it>E. dispar </it>trophozoites. Trophozoites of <it>E. dispar </it>were also more frequently vacuolated and high labeled cellular debris observed in the lesions. Positive diffuse reaction to C3 complement component was more intense in livers of animals inoculated with <it>E. histolytica </it>after 24 and 72 h of infection. C3<sup>(+) </sup>and C9<sup>(+) </sup>trophozoites were detected in the vascular lumen, granulomas and inside and in the border of necrotic areas of both infected group animals. C3<sup>(+) </sup>and C9<sup>(+) </sup>trophozoite debris immunostaining was higher in livers of <it>E. dispar </it>than in livers of <it>E. histolytica</it>. A positive correlation between necrotic areas and number of C9<sup>(+) </sup>trophozoites was observed in animals inoculated with <it>E. dispar</it>.</p> <p>Conclusion</p> <p>Morphological and immunohistochemical results suggest that antibodies and complement are able to bind and destroy some trophozoites in the liver of experimentally infected hamsters, perhaps selecting the more resistant parasites which are responsible by progression of amoebic abscesses. The findings indicate that <it>E. histolytica </it>possesses an enhanced ability <it>in vivo </it>to evade the immune responses compared to <it>E. dispar</it>, although it also causes experimental hepatic lesions.</p>
url http://www.parasitesandvectors.com/content/3/1/23
work_keys_str_mv AT gomesmariaa itentamoebahistolyticaitanditedisparittrophozoitesintheliverofhamstersinvivobindingofantibodiesandcomplement
AT ferreiraandersonj itentamoebahistolyticaitanditedisparittrophozoitesintheliverofhamstersinvivobindingofantibodiesandcomplement
AT nunesalvaroc itentamoebahistolyticaitanditedisparittrophozoitesintheliverofhamstersinvivobindingofantibodiesandcomplement
AT costacassiaax itentamoebahistolyticaitanditedisparittrophozoitesintheliverofhamstersinvivobindingofantibodiesandcomplement
AT caliarimarcelov itentamoebahistolyticaitanditedisparittrophozoitesintheliverofhamstersinvivobindingofantibodiesandcomplement
_version_ 1724828727466000384