Toxoplasma gondii Chitinase Induces Macrophage Activation

PLoS One. 2015 Dec 10;10(12):e0144507. doi: 10.1371/journal.pone.0144507.

 

Almeida F¹, Sardinha-Silva A¹, da Silva TA¹, Pessoni AM¹, Pinzan CF¹, Alegre-Maller AC¹, Cecílio NT¹, Moretti NS², Damásio AR³, Pedersoli WR⁴, Mineo JR⁵, Silva RN⁴, Roque-Barreira MC¹.

 

Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50°C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection.

PMID:

26659253

[PubMed - as supplied by publisher]