Enterocin AS-48 as Evidence for the Use of Bacteriocins as New Leishmanicidal Agents.
We report the feasibility of enterocin AS-48, a circular cationic peptide produced byEnterococcus faecalis, as a new leishmanicidal agent. AS-48 is lethal toLeishmaniapromastigotes as well as to axenic and intracellular amastigotes at low micromolar concentrations, with scarce cytotoxicity to macrophages. AS-48 induced a fast bioenergetic collapse ofL. donovanipromastigotes but only a partial permeation of their plasma membrane with limited entrance of vital dyes, even at concentrations beyond its full lethality. Fluoresceinated AS-48 was visualized inside parasites by confocal microscopy and seen to cause mitochondrial depolarization and reactive oxygen species production. Altogether, AS-48 appeared to have a mixed leishmanicidal mechanism that includes both plasma membrane permeabilization and additional intracellular targets, with mitochondrial dysfunctionality being of special relevance. This complex leishmanicidal mechanism of AS-48 persisted even for the killing of intracellular amastigotes, as evidenced by transmission electron microscopy. We demonstrated the potentiality of AS-48 as a new and safe leishmanicidal agent, expanding the growing repertoire of eukaryotic targets for bacteriocins, and our results provide a proof of mechanism for the search of new leishmanicidal bacteriocins, whose diversity constitutes an almost endless source for new structures at moderate production cost and whose safe use on food preservation is well established.
Centro de Investigaciones Biológicas (CSIC), Physico-Chemical Biology Department Unidad Asociada Interacciones, Metabolismo y Bioanálisis CSIC-CEU, Madrid, Spain.
María Ángeles
MÁ
Abengózar
Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Rubén
R
Cebrián
Centro de Investigaciones Biológicas (CSIC), Physico-Chemical Biology Department Unidad Asociada Interacciones, Metabolismo y Bioanálisis CSIC-CEU, Madrid, Spain.|Helminth Unit, Parasitology Department, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.
José María
JM
Saugar
Helminth Unit, Parasitology Department, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain.
Teresa
T
Gárate
Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Eva
E
Valdivia
Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Manuel
M
Martínez-Bueno
Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Mercedes
M
Maqueda
Centro de Investigaciones Biológicas (CSIC), Physico-Chemical Biology Department Unidad Asociada Interacciones, Metabolismo y Bioanálisis CSIC-CEU, Madrid, Spain luis.rivas@cib.csic.es.
Luis
L
Rivas
D000255:Adenosine Triphosphate / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001430:Bacteriocins / Q000302:isolation & purification / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D013293:Enterococcus faecalis / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D020128:Inhibitory Concentration 50; D007893:Leishmania donovani / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008018:Life Cycle Stages / Q000187:drug effects* / Q000502:physiology; D008264:Macrophages / Q000187:drug effects / Q000469:parasitology; D008854:Microscopy, Electron; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D013045:Species Specificity; D013194:Staining and Labeling / Q000379:methods
D000981:Antiprotozoal Agents; D001430:Bacteriocins; D005456:Fluorescent Dyes; C466236:enterocin AS-48, Enterococcus faecalis; D000255:Adenosine Triphosphate
antimicrobial peptide; bioenergetics; enterocin AS-48; intracellular parasite