Decreased <i>Leishmania</i> species infection and increased leishmanicidal molecules after IL-32 overexpression in human THP-1-derived macrophages.

<p>PMA-differentiated THP-1 cells (2.5 x 10⁶ cells/800 μL) were electroporated by using Amaxa Nucleofector Technology with IL-32 plasmid (for IL-32 overexpression) and egfp plasmid (as a control). The final concentration of cells per well were 3 x 10⁵ cells/100 μL. After 24 h of transfection, cells were infected with promastigote forms (1.5 x 10⁶ parasites) in the growth stationary phase of <i>L</i>. (<i>L</i>.) <i>amazonensis</i> (<i>L</i>. <i>amaz</i>) or metacyclic promastigote forms (1.5 x 10⁶ parasites) of <i>L</i>. (<i>V</i>.) <i>braziliensis</i> (<i>L</i>. <i>braz</i>). After 4 h, non-internalized parasites were washed out and cells were incubated for 24 h or 48 h. Cells were stained and percentage of infected macrophages, number of parasites per infected cells, and infection index were evaluated. (A) infection with <i>L</i>. <i>amazonensis</i>; (B) infection with <i>L</i>. <i>braziliensis</i>. iNOS (C—left panel) and cathelidicin (D—left panel) and β-defensin 2 (E) mRNA expression were determined by quantitative real-time PCR (24 h). Nitrite production (C—right panel) and LL-37 production (D—right panel) were determined by Griess reagent and ELISA in supernatants, respectively (24 h). Values are expressed as means ± SEM of three independent experiments. *p < 0.05 (egpf plasmid vs IL-32γ plasmid).