Toxoplasma gondii 70 kDa Heat Shock Protein: Increased Expression in the Brain Is Associated with Parasite Replication

PLoS One. 2014 May 6;9(5):e96527. doi: 10.1371/journal.pone.0096527. eCollection 2014.

Toxoplasma gondii 70 kDa Heat Shock Protein: Systemic Detection Is Associated with the Death of the Parasites by the Immune Response and Its Increased Expression in the Brain Is Associated with Parasite Replication

Barenco PV¹, Lourenço EV², Cunha-Júnior JP³, Almeida KC¹, Roque-Barreira MC², Silva DA⁴, Araújo EC¹, Coutinho LB¹, Oliveira MC¹, Mineo TW⁴, Mineo JR⁴, Silva NM¹.

Author information

• ¹Laboratory of Immunopathology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, MG, Brazil.
• ²Department of Cellular and Molecular Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
• ³Laboratory of Immunotechnology and Immunochemistry, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, MG, Brazil.
• ⁴Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, Uberlândia, MG, Brazil.

Abstract

The heat shock protein of Toxoplasma gondii (TgHSP70) is a parasite virulence factor that is expressed during T. gondii stage conversion. To verify the effect of dexamethasone (DXM)-induced infection reactivation in the TgHSP70-specific humoral immune response and the presence of the protein in the mouse brain, we produced recombinant TgHSP70 and anti-TgHSP70 IgY antibodies to detect the protein, the specific antibody and levels of immune complexes (ICs) systemically, as well as the protein in the brain of resistant (BALB/c) and susceptible (C57BL/6) mice. It was observed higher TgHSP70-specific antibody titers in serum samples of BALB/c compared with C57BL/6 mice. However, the susceptible mice presented the highest levels of TgHSP70 systemically and no detection of specific ICs. The DXM treatment induced increased parasitism and lower inflammatory changes in the brain of C57BL/6, but did not interfere with the cerebral parasitism in BALB/c mice. Additionally, DXM treatment decreased the serological TgHSP70 concentration in both mouse lineages. C57BL/6 mice presented high expression of TgHSP70 in the brain with the progression of infection and under DXM treatment. Taken together, these data indicate that the TgHSP70 release into the bloodstream depends on the death of the parasites mediated by the host immune response, whereas the increased TgHSP70 expression in the brain depends on the multiplication rate of the parasite.

PMID:

24801069

[PubMed - in process]