Macrophage M1/M2 polarization induced by lipids from Leishmania braziliensis promastigotes and amastigotes

CARFAGNA I; BOTT E; LAMMEL EM; GIMENEZ G; BELAUNZARÁN ML

Congreso; World Leish6; 2017

Macrophage M1/M2 polarization induced by lipids from Leishmania braziliensis promastigotes and amastigotesCarfagna, Ivanna E; Bott, Emanuel; Lammel, Estela M; Gimenez, Guadalupe and Belaunzarán, María Laura.BackgroundInfections control depends on innate immunity activation and there is evidence of the immunomodulatory role that pathogens´ lipids display in this process where macrophages play a key role, being classified into M1 (classical) and M2 (alternative) activation phenotypes. Control of Leishmania spp infection requires a pro-inflammatory profile with M1 macrophages; though the parasite has developed strategies to evade this response.In L. braziliensis, agent of cutaneous Leishmaniasis, we found quantitative differences in the lipid profiles of promastigotes (PRO) and amastigotes (AMA), as well as after parasite disruption and incubation that generates bioactive lipids which may contribute to inflammation. We here studied the effect of total lipids from PRO and AMA (intact and post-incubation) in lipid bodies? induction, ciclooxigenase-2 (COX-2) expression and macrophage M1/M2 polarization.MethodsL. braziliensis MHOM/BR/75M2904, PRO or AMA (1-3x108/ml) were lysed by 3 cycles of N2/37°C + protease inhibitors. Lipids were extracted following Bligh & Dyer, dried under N2 to constant weight and suspended in ethanol. Parasites were also incubated for 20 h at 37°C to allow lipids hydrolysis and then extracted and processed as mentioned (PROinc and AMAinc).Murine peritoneal macrophages (1x106/well) were stimulated with 50 µg/ml of the different lipids for 24-48 h at 37ºC and 5% CO2 to determine: Lipid bodies formation (Gimenez et al, 2010), COX-2, inducible nitric oxide synthase (iNOS) and Arginase-1 expression by Immunoblot, Nitric oxide (NO) using Griess reaction (Shoda et al, 2000) and Arginase activity (Al-Mutairi MS et al, 2010).ResultsWe determined that PRO induced the highest Arginase-1 expression/activity, lower iNOS expression and NO production, suggesting an anti-inflammatory response with M2 macrophages. In contrast, AMAinc induced the highest iNOS expression and NO production and lower Arginase-1 expression/activity, suggesting a pro-inflammatory response, related to M1 macrophages. As concerns lipid bodies, all the lipids analyzed induced their generation, whereas the higher levels of COX-2 expression were obtained with AMAinc.ConclusionsThe results suggest that PRO, PROinc, AMA and AMAinc may differentially contribute to the modulation of the immune response; this could be related to their different lipid profiles, thus bioactive lipids from L. braziliensis could be good candidates for immunoprophylactic strategies. Supported by CONICET/UBA