RESUMO
OBJECTIVE AND DESIGN: Paracoccin (PCN), a lectin expressed by Paracoccidioides brasiliensis (Pb), is known to exert activities on the fungal biology, as well as different immune cells of myeloid origin. The aim of this study was to investigate the direct interaction of the recombinant form of the lectin (rPCN) with neutrophils, a neglected area. MATERIALS OR SUBJECTS: Freshly isolated human neutrophils from healthy donors were used. TREATMENT: Neutrophils were incubated with rPCN in vitro. METHODS: After the treatment, the production of reactive oxygen species (ROS), DNA release, IL-8, TNF, IFN-γ, IL-10, IL-12p40, TGF-ß and IL-1ß production, fungicidal ability, apoptosis and de novo protein synthesis was determined. RESULTS: rPCN was found to induce ROS production as well as DNA release. Using the ROS inhibitor, diphenyleneiodium, both ROS production and DNA release were significantly inhibited. In addition, rPCN was found to induce IL-8 and IL1-ß production, inhibit apoptosis and induce de novo protein synthesis. Addition of cycloheximide, a protein synthesis inhibitor, drastically reversed the antiapoptotic effect of rPCN. Finally, the ability to kill Pb yeasts by human neutrophils was significantly increased after rPCN stimulation. CONCLUSIONS: rPCN can alter the biology of human neutrophils increasing their fungicidal ability. Moreover, the ability of rPCN to increase DNA release and to induce suppression of neutrophil apoptosis occurs by a ROS- and de novo protein synthesis-dependent mechanism, respectively.
Assuntos
Proteínas Fúngicas/farmacologia , Lectinas/farmacologia , Neutrófilos/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , DNA/metabolismo , Humanos , Neutrófilos/metabolismo , Paracoccidioides , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/farmacologiaRESUMO
AIMS: The aim of the present work was to study the in vitro effect of native and recombinant Bauhinia variegata var. variegata lectins in inhibiting early adhesion of Streptococcus mutans, Streptococcus sanguis and Streptococcus sobrinus to experimentally acquired pellicle. METHODS AND RESULTS: Native lectin from B. variegata (BVL) was purified by affinity chromatography of extract of seeds. The recombinant lectin (rBVL-I) was expressed in E. coli strain BL21 (DE3) from a genomic clone encoding the mature B. variegata lectin gene using the vector pAE-bvlI. Recombinant protein deposited in inclusion bodies was solubilized and subsequently purified by affinity chromatography. The rBVL-I was compared to BVL for agglutination of erythrocytes and initial adherence of oral bacteria on a saliva-coated surface. The results revealed that rBVL-I acts similarly to BVL for agglutination of erythrocytes. Both lectins showed adhesion inhibition effect on Step. sanguis, Step. mutans and Step. sobrinus. CONCLUSION: We report, for the first time, the inhibition of early adhesion of oral bacteria by a recombinant lectin. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results support the proposed biotechnological application of lectins in a strategy to reduce development of dental caries by inhibiting the initial adhesion and biofilm formation.