The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis

Detalhes bibliográficos
Autor(a) principal: Pinheiro,Roberta O.
Data de Publicação: 2004
Outros Autores: Pinto,Eduardo F., Benedito,Alessandra B., Lopes,Ulisses G., Rossi-Bergmann,Bartira
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Anais da Academia Brasileira de Ciências (Online)
Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300006
Resumo: Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.
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spelling The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosisLeishmaniaanergyapoptosisLeishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.Academia Brasileira de Ciências2004-09-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300006Anais da Academia Brasileira de Ciências v.76 n.3 2004reponame:Anais da Academia Brasileira de Ciências (Online)instname:Academia Brasileira de Ciências (ABC)instacron:ABC10.1590/S0001-37652004000300006info:eu-repo/semantics/openAccessPinheiro,Roberta O.Pinto,Eduardo F.Benedito,Alessandra B.Lopes,Ulisses G.Rossi-Bergmann,Bartiraeng2004-08-23T00:00:00Zoai:scielo:S0001-37652004000300006Revistahttp://www.scielo.br/aabchttps://old.scielo.br/oai/scielo-oai.php||aabc@abc.org.br1678-26900001-3765opendoar:2004-08-23T00:00Anais da Academia Brasileira de Ciências (Online) - Academia Brasileira de Ciências (ABC)false
dc.title.none.fl_str_mv The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
title The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
spellingShingle The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
Pinheiro,Roberta O.
Leishmania
anergy
apoptosis
title_short The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
title_full The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
title_fullStr The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
title_full_unstemmed The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
title_sort The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis
author Pinheiro,Roberta O.
author_facet Pinheiro,Roberta O.
Pinto,Eduardo F.
Benedito,Alessandra B.
Lopes,Ulisses G.
Rossi-Bergmann,Bartira
author_role author
author2 Pinto,Eduardo F.
Benedito,Alessandra B.
Lopes,Ulisses G.
Rossi-Bergmann,Bartira
author2_role author
author
author
author
dc.contributor.author.fl_str_mv Pinheiro,Roberta O.
Pinto,Eduardo F.
Benedito,Alessandra B.
Lopes,Ulisses G.
Rossi-Bergmann,Bartira
dc.subject.por.fl_str_mv Leishmania
anergy
apoptosis
topic Leishmania
anergy
apoptosis
description Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg) but not L. braziliensis promastigotes (LbAg) contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h) and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.
publishDate 2004
dc.date.none.fl_str_mv 2004-09-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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dc.identifier.uri.fl_str_mv http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300006
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300006
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0001-37652004000300006
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dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Academia Brasileira de Ciências
publisher.none.fl_str_mv Academia Brasileira de Ciências
dc.source.none.fl_str_mv Anais da Academia Brasileira de Ciências v.76 n.3 2004
reponame:Anais da Academia Brasileira de Ciências (Online)
instname:Academia Brasileira de Ciências (ABC)
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instname_str Academia Brasileira de Ciências (ABC)
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reponame_str Anais da Academia Brasileira de Ciências (Online)
collection Anais da Academia Brasileira de Ciências (Online)
repository.name.fl_str_mv Anais da Academia Brasileira de Ciências (Online) - Academia Brasileira de Ciências (ABC)
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