Insights into anti-parasitism induced by a C-type lectin from Bothrops pauloensis venom on Toxoplasma gondii.

Here we evaluate the effects of BpLec, a C-type lectin isolated from Bothrops pauloensis snake venom, on Toxoplasma gondii parasitism. BpLec (0.195-12.5 μg/mL) did not interfere with HeLa (host cell) viability by MTT assay, whereas higher doses decreased viability and changed HeLa morphology. In addition, the host cell treatment before infection did not influence adhesion and proliferation indexes. BpLec did not alter T. gondii tachyzoite viability, as carried out by trypan blue exclusion, but decreased both adhesion and parasite replication, when tachyzoites were treated before infection. Galactose (0.4 M) inhibited the BpLec effect on adhesion assays, suggesting that BpLec probably recognize some glycoconjugate from T. gondii membrane. Additionally, we performed cytokine measurements from supernatants collected from HeLa cells infected with T. gondii tachyzoites previously treated with RPMI or BpLec. MIF and IL-6 productions by HeLa cells were increased by BpLec treatment. Also, TGF-β1 secretion was diminished post-infection, although this effect was not dependent on BpLec treatment. Taken together, our results show that BpLec is capable of reducing T. gondii parasitism after tachyzoite treatment and may represent an interesting tool in the search for parasite antigens involved in these processes.