Leishmania (Viannia) braziliensis Thor strain and subpopulations Thor03, Thor10, and Thor22 have differences in the surface membrane proteases activity profile

The Leishmania (Viannia) braziliensis Thor strain is composed of subpopulations with distinct biological features, as differences of the virulence profile in vitro and in vivo in murine model. As the surface of these parasites is the first contact with the host, this study assesses comparative approaches of surface membrane proteases of promastigotes and axenic amastigotes of L. (V.) braziliensis Thor strain and Thor03, Thor10, and Thor22 subpopulations, accessing differential profiles among these parasites. Here is explored the phospholipase C (PLC) property as a pivotal tool to selectively recover surface proteases of these parasites. The treatment of parasites with PLC yielded protein fractions with metalloprotease, cysteine protease, and serine protease activities, which were detectable by gelatin-SDS-PAGE and fluorogenic substrates and specific inhibitors, showing distinct profiles from both promastigotes and axenic amastigotes of the Thor strain, Thor03, Thor10, and Thor22 subpopulations. Data of protease activity quantitative in solution show metalloprotease as the highest activity, followed by cysteine protease and serine protease onto the surface of promastigotes and axenic amastigotes. The biological significance of these findings points to the potential of the Thor strain, helped by respective subpopulations, to adapt to hosts, as well as reinforcing the importance of this class of enzyme in the first hours of infection.