Efeito de lectinas vegetais de pisum arvense, Bauhinia variegata, Arum maculatum e Helianthus tuberosus, na migração de neutrófilos e interação com células inflamatórias

Abstract

Lectins are a group of carbohydrate-binding proteins of nonimmune origin. Studies demonstrate that these proteins possess important biological activities in the recognition of cancerous cells, stimulation of the immune system, also serving as study tools, for identification of carbohydrates, or insecticide, among others. Following this line the objectives of this work was to investigate the pro-inflammatory activity of the lectins from Pisum arvense (PAL), Bauhinia variegata (BVL), Arum maculatum (AMA) and Helianthus tuberosus (HTA), and their interactions with immune system cells. In the study of pro-inflammatory activity of lectins, experiments, in vivo (rats), of neutrophil migration (MN) has been performed, using the peritonitis model and, in vitro, MN was evaluated in Boyden's chamber. In the experiments of MN, in vivo, the role of resident cells, in induction of migration had been evaluated by lavage of the peritoneal cavities of the rats, as well as treatments with tioglicolato (Tg) 3%, 48/80 compound and injection of supernatant from macrophages culture stimulated by lectins. In all experiments, the MN was evaluated 4h afterthe injection of stimuli, and these stimuli had been injected always after the treatments or procedures of lavage. The evaluation of lectin effects was even performed blocking the carbohydrate-binding site with their specific sugars previously to the stimulus. For lectin-cell interaction analysis, lectins were marked with FITC, incubated for 30 min at 4°C to the macrophages (Mo) and mast cells (MC) from rats, and to human neutrophil and monocytes. After incubation, differences of fluorescence intensity (IF) of cells were examined by flow cytometry. The results had shown that the four lectins had significant effect on MN. The depletion of resident cells (lavage), did not inhibit the induced MN by PAL, AMA, HTA, but inhibited the BVL effect. The treatment with Tg enhanced the MN induced by PAL, AMA and BVL, but it did not modify the MN induced by HTA. The depletion of MC by 48/80 enhanced the MN induced by PAL, HTA and BVL, but it did not modify the AMA-effect. The injection of the supernatant of macrophages culture, stimulated by PAL, AMA and BVL, but not by HTA, induced MN. In vitro, PAL, BVL, AMA and HTA have induced significantly MN. Incubation FITC-lectins to Mo, MC, neutrophils and monocytes, increased the IF in a magnitude as higheras 238, 363, 792 and 453% respectively, for PAL; 479, 136, 213 and 281% respectively for BVL; 625, 279, 213 and 486% respectively for AMA and 89, 187, 243, 94% respectively for HTA. In conclusion: The PAL, BVL, AMA and HTA are pro- inflammatory and bind significantly to Mo, MC, neutrophils and monocytes. However, the mechanisms of induction of MN and interactions to cells are differently, depending on the studied lectin.