A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge.
Trypanosoma cruzi calreticulin (TcCRT) is a virulence factor that binds complement C1, thus inhibiting the activation of the classical complement pathway and generating pro-phagocytic signals that increase parasite infectivity. In a previous work, we characterized a clonal cell line lacking one TcCR...
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doaj-4b3d1566919f447997761e1ec7ba38232020-11-25T01:43:05ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352014-02-0182e269610.1371/journal.pntd.0002696A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge.Fernando J Sánchez-ValdézCecilia Pérez BrandánGalia RamírezAlejandro D UncosM Paola ZagoRubén O CiminoRubén M CardozoJorge D MarcoArturo FerreiraMiguel Ángel BasombríoTrypanosoma cruzi calreticulin (TcCRT) is a virulence factor that binds complement C1, thus inhibiting the activation of the classical complement pathway and generating pro-phagocytic signals that increase parasite infectivity. In a previous work, we characterized a clonal cell line lacking one TcCRT allele (TcCRT+/-) and another overexpressing it (TcCRT+), both derived from the attenuated TCC T. cruzi strain. The TcCRT+/- mutant was highly susceptible to killing by the complement machinery and presented a remarkable reduced propagation and differentiation rate both in vitro and in vivo. In this report, we have extended these studies to assess, in a mouse model of disease, the virulence, immunogenicity and safety of the mutant as an experimental vaccine. Balb/c mice were inoculated with TcCRT+/- parasites and followed-up during a 6-month period. Mutant parasites were not detected by sensitive techniques, even after mice immune suppression. Total anti-T. cruzi IgG levels were undetectable in TcCRT+/- inoculated mice and the genetic alteration was stable after long-term infection and it did not revert back to wild type form. Most importantly, immunization with TcCRT+/- parasites induces a highly protective response after challenge with a virulent T. cruzi strain, as evidenced by lower parasite density, mortality, spleen index and tissue inflammatory response. TcCRT+/- clones are restricted in two important properties conferred by TcCRT and indirectly by C1q: their ability to evade the host immune response and their virulence. Therefore, deletion of one copy of the TcCRT gene in the attenuated TCC strain generated a safe and irreversibly gene-deleted live attenuated parasite with high immunoprotective properties. Our results also contribute to endorse the important role of TcCRT as a T. cruzi virulence factor.http://europepmc.org/articles/PMC3923724?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Fernando J Sánchez-Valdéz Cecilia Pérez Brandán Galia Ramírez Alejandro D Uncos M Paola Zago Rubén O Cimino Rubén M Cardozo Jorge D Marco Arturo Ferreira Miguel Ángel Basombrío |
spellingShingle |
Fernando J Sánchez-Valdéz Cecilia Pérez Brandán Galia Ramírez Alejandro D Uncos M Paola Zago Rubén O Cimino Rubén M Cardozo Jorge D Marco Arturo Ferreira Miguel Ángel Basombrío A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. PLoS Neglected Tropical Diseases |
author_facet |
Fernando J Sánchez-Valdéz Cecilia Pérez Brandán Galia Ramírez Alejandro D Uncos M Paola Zago Rubén O Cimino Rubén M Cardozo Jorge D Marco Arturo Ferreira Miguel Ángel Basombrío |
author_sort |
Fernando J Sánchez-Valdéz |
title |
A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
title_short |
A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
title_full |
A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
title_fullStr |
A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
title_full_unstemmed |
A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
title_sort |
monoallelic deletion of the tccrt gene increases the attenuation of a cultured trypanosoma cruzi strain, protecting against an in vivo virulent challenge. |
publisher |
Public Library of Science (PLoS) |
series |
PLoS Neglected Tropical Diseases |
issn |
1935-2727 1935-2735 |
publishDate |
2014-02-01 |
description |
Trypanosoma cruzi calreticulin (TcCRT) is a virulence factor that binds complement C1, thus inhibiting the activation of the classical complement pathway and generating pro-phagocytic signals that increase parasite infectivity. In a previous work, we characterized a clonal cell line lacking one TcCRT allele (TcCRT+/-) and another overexpressing it (TcCRT+), both derived from the attenuated TCC T. cruzi strain. The TcCRT+/- mutant was highly susceptible to killing by the complement machinery and presented a remarkable reduced propagation and differentiation rate both in vitro and in vivo. In this report, we have extended these studies to assess, in a mouse model of disease, the virulence, immunogenicity and safety of the mutant as an experimental vaccine. Balb/c mice were inoculated with TcCRT+/- parasites and followed-up during a 6-month period. Mutant parasites were not detected by sensitive techniques, even after mice immune suppression. Total anti-T. cruzi IgG levels were undetectable in TcCRT+/- inoculated mice and the genetic alteration was stable after long-term infection and it did not revert back to wild type form. Most importantly, immunization with TcCRT+/- parasites induces a highly protective response after challenge with a virulent T. cruzi strain, as evidenced by lower parasite density, mortality, spleen index and tissue inflammatory response. TcCRT+/- clones are restricted in two important properties conferred by TcCRT and indirectly by C1q: their ability to evade the host immune response and their virulence. Therefore, deletion of one copy of the TcCRT gene in the attenuated TCC strain generated a safe and irreversibly gene-deleted live attenuated parasite with high immunoprotective properties. Our results also contribute to endorse the important role of TcCRT as a T. cruzi virulence factor. |
url |
http://europepmc.org/articles/PMC3923724?pdf=render |
work_keys_str_mv |
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