Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.

Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis for which an effective vaccine is needed. Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by T. gondii. This...

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Main Authors: Li-Tian Yin, Hai-Xia Hao, Hai-Long Wang, Jian-Hong Zhang, Xiao-Li Meng, Guo-Rong Yin
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3873923?pdf=render
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author Li-Tian Yin
Hai-Xia Hao
Hai-Long Wang
Jian-Hong Zhang
Xiao-Li Meng
Guo-Rong Yin
author_facet Li-Tian Yin
Hai-Xia Hao
Hai-Long Wang
Jian-Hong Zhang
Xiao-Li Meng
Guo-Rong Yin
author_sort Li-Tian Yin
collection DOAJ
description Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis for which an effective vaccine is needed. Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by T. gondii. This study investigated the immune responses elicited by BALB/c mice after nasal immunisation with a recombinant T. gondii actin (rTgACT) and the subsequent protection against chronic and lethal T. gondii infections. We evaluated the systemic response by proliferation, cytokine and antibody measurements, and we assessed the mucosal response by examining the levels of TgACT-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes. Parasite load was assessed in the liver and brain, and the survival of mice challenged with a virulent strain was determined. The results showed that the mice immunised with rTgACT developed high levels of specific anti-rTgACT IgG titres and a mixed IgG1/IgG2a response with a predominance of IgG2a. The systemic immune response was associated with increased production of Th1 (IFN-γ and IL-2), Th2 (IL-4) and Treg (IL-10) cytokines, indicating that not only Th1-type response was induced, but also Th2- and Treg-types responses were induced, and the splenocyte stimulation index (SI) was increased in the mice immunised with rTgACT. Nasal immunisation with rTgACT led to strong mucosal immune responses, as seen by the increased secretion of SIgA in nasal, vaginal and intestinal washes. The vaccinated mice displayed significant protection against lethal infection with the virulent RH strain (survival increased by 50%), while the mice chronically infected with RH exhibited lower liver and brain parasite loads (60.05% and 49.75%, respectively) than the controls. Our data demonstrate, for the first time, that actin triggers a strong systemic and mucosal response against T. gondii. Therefore, actin may be a promising vaccine candidate against toxoplasmosis.
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spelling doaj.art-8f9df9acaaa7471eb216e4e5410e2a6d2022-12-22T00:58:47ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-01812e8276510.1371/journal.pone.0082765Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.Li-Tian YinHai-Xia HaoHai-Long WangJian-Hong ZhangXiao-Li MengGuo-Rong YinToxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis for which an effective vaccine is needed. Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by T. gondii. This study investigated the immune responses elicited by BALB/c mice after nasal immunisation with a recombinant T. gondii actin (rTgACT) and the subsequent protection against chronic and lethal T. gondii infections. We evaluated the systemic response by proliferation, cytokine and antibody measurements, and we assessed the mucosal response by examining the levels of TgACT-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes. Parasite load was assessed in the liver and brain, and the survival of mice challenged with a virulent strain was determined. The results showed that the mice immunised with rTgACT developed high levels of specific anti-rTgACT IgG titres and a mixed IgG1/IgG2a response with a predominance of IgG2a. The systemic immune response was associated with increased production of Th1 (IFN-γ and IL-2), Th2 (IL-4) and Treg (IL-10) cytokines, indicating that not only Th1-type response was induced, but also Th2- and Treg-types responses were induced, and the splenocyte stimulation index (SI) was increased in the mice immunised with rTgACT. Nasal immunisation with rTgACT led to strong mucosal immune responses, as seen by the increased secretion of SIgA in nasal, vaginal and intestinal washes. The vaccinated mice displayed significant protection against lethal infection with the virulent RH strain (survival increased by 50%), while the mice chronically infected with RH exhibited lower liver and brain parasite loads (60.05% and 49.75%, respectively) than the controls. Our data demonstrate, for the first time, that actin triggers a strong systemic and mucosal response against T. gondii. Therefore, actin may be a promising vaccine candidate against toxoplasmosis.http://europepmc.org/articles/PMC3873923?pdf=render
spellingShingle Li-Tian Yin
Hai-Xia Hao
Hai-Long Wang
Jian-Hong Zhang
Xiao-Li Meng
Guo-Rong Yin
Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
PLoS ONE
title Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
title_full Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
title_fullStr Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
title_full_unstemmed Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
title_short Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.
title_sort intranasal immunisation with recombinant toxoplasma gondii actin partly protects mice against toxoplasmosis
url http://europepmc.org/articles/PMC3873923?pdf=render
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