Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.

Pathogens express ligands for several TLRs that may play a role in the induction or control of the inflammatory response during infection. Concerning Trypanosoma cruzi, the agent of Chagas disease, we have previously characterized glycosylphosphatidylinositol (GPI) anchored mucin-like glycoproteins...

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Main Authors: Humberto D Gravina, Lis Antonelli, Ricardo T Gazzinelli, Catherine Ropert
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3641106?pdf=render
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author Humberto D Gravina
Lis Antonelli
Ricardo T Gazzinelli
Catherine Ropert
author_facet Humberto D Gravina
Lis Antonelli
Ricardo T Gazzinelli
Catherine Ropert
author_sort Humberto D Gravina
collection DOAJ
description Pathogens express ligands for several TLRs that may play a role in the induction or control of the inflammatory response during infection. Concerning Trypanosoma cruzi, the agent of Chagas disease, we have previously characterized glycosylphosphatidylinositol (GPI) anchored mucin-like glycoproteins (tGPI-mucin) and unmethylated CpG DNA sequences as TLR2 and TLR9 agonists, respectively. Here we sought to determine how these TLRs may modulate the inflammatory response in the following cell populations: F4/80(+)CD11b(+) (macrophages), F4/80(low)CD11b(+) (monocytes) and MHCII(+)CD11c(high) (dendritic cells). For this purpose, TLR2(-/-) and TLR9(-/-) mice were infected with Y strain of T. cruzi and different immunological parameters were evaluated. According to our previous data, a crucial role of TLR9 was evidenced in the establishment of Th1 response, whereas TLR2 appeared to act as immunoregulator in the early stage of infection. More precisely, we demonstrated here that TLR2 was mainly used by F4/80(+)CD11b(+) cells for the production of TNF-α. In the absence of TLR2, an increased production of IL-12/IL-23p40 and IFN-γ was noted suggesting that TLR2 negatively controls the Th1 response. In contrast, TLR9 was committed to IL-12/IL-23p40 production by MHCII(+)CD11c(high) cells that constitute the main source of IL-12/IL-23p40 during infection. Importantly, a down-regulation of TLR9 response was observed in F4/80(+)CD11b(+) and F4/80(low)CD11b(+) populations that correlated with the decreased TLR9 expression level in these cells. Interestingly, these cells recovered their capacity to respond to TLR9 agonist when MHCII(+)CD11c(high) cells were impeded from producing IL-12/IL-23p40, thereby indicating possible cross-talk between these populations. The differential use of TLR2 and TLR9 by the immune cells during the acute phase of the infection explains why TLR9- but not TLR2-deficient mice are susceptible to T. cruzi infection.
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spelling doaj.art-7b6d44c965734cd5bb49a1731b8a0e322022-12-22T02:04:25ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0185e6310010.1371/journal.pone.0063100Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.Humberto D GravinaLis AntonelliRicardo T GazzinelliCatherine RopertPathogens express ligands for several TLRs that may play a role in the induction or control of the inflammatory response during infection. Concerning Trypanosoma cruzi, the agent of Chagas disease, we have previously characterized glycosylphosphatidylinositol (GPI) anchored mucin-like glycoproteins (tGPI-mucin) and unmethylated CpG DNA sequences as TLR2 and TLR9 agonists, respectively. Here we sought to determine how these TLRs may modulate the inflammatory response in the following cell populations: F4/80(+)CD11b(+) (macrophages), F4/80(low)CD11b(+) (monocytes) and MHCII(+)CD11c(high) (dendritic cells). For this purpose, TLR2(-/-) and TLR9(-/-) mice were infected with Y strain of T. cruzi and different immunological parameters were evaluated. According to our previous data, a crucial role of TLR9 was evidenced in the establishment of Th1 response, whereas TLR2 appeared to act as immunoregulator in the early stage of infection. More precisely, we demonstrated here that TLR2 was mainly used by F4/80(+)CD11b(+) cells for the production of TNF-α. In the absence of TLR2, an increased production of IL-12/IL-23p40 and IFN-γ was noted suggesting that TLR2 negatively controls the Th1 response. In contrast, TLR9 was committed to IL-12/IL-23p40 production by MHCII(+)CD11c(high) cells that constitute the main source of IL-12/IL-23p40 during infection. Importantly, a down-regulation of TLR9 response was observed in F4/80(+)CD11b(+) and F4/80(low)CD11b(+) populations that correlated with the decreased TLR9 expression level in these cells. Interestingly, these cells recovered their capacity to respond to TLR9 agonist when MHCII(+)CD11c(high) cells were impeded from producing IL-12/IL-23p40, thereby indicating possible cross-talk between these populations. The differential use of TLR2 and TLR9 by the immune cells during the acute phase of the infection explains why TLR9- but not TLR2-deficient mice are susceptible to T. cruzi infection.http://europepmc.org/articles/PMC3641106?pdf=render
spellingShingle Humberto D Gravina
Lis Antonelli
Ricardo T Gazzinelli
Catherine Ropert
Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
PLoS ONE
title Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
title_full Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
title_fullStr Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
title_full_unstemmed Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
title_short Differential use of TLR2 and TLR9 in the regulation of immune responses during the infection with Trypanosoma cruzi.
title_sort differential use of tlr2 and tlr9 in the regulation of immune responses during the infection with trypanosoma cruzi
url http://europepmc.org/articles/PMC3641106?pdf=render
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