Influence of the neutrophil infection upon the virulence factors of the Leishmania mexicana and Leishmania major parasites

Abstract

Neutrophils are generally the first phagocytes to migrate during infection caused by Leishmania protozoa parasites to the infectious focus. Its protective effect is directly associated with its ability to phagocyte, activate and eliminate the parasites. After ingestion, the pathogen particles are eliminated through oxidative and non-oxidative mechanisms. The oxidative mechanisms involve the production of reactive oxygen species (ROS) through the enzyme NADPH oxidase, and non-oxidative by the release of peptides, antimicrobial proteases and the expulsion of their nuclear contents to form neutrophils extracellular traps. Although neutrophils exhibit several effector functions, these cells are also exploited by Leishmania to evade the immune system and promote the parasite spreading. The mechanisms by which neutrophils interfere in the development of effector immune responses are unclear. It is known that during L. mexicana infection, the parasite is sequestered by neutrophils, there is inhibition of recruitment and effector functions of dendritic cells that affect the development of the Th1 protective immune response. As a consequence, there is the spreading of parasites and the development of chronic lesions. Thus, we propose that to survive in the hostile interior of neutrophils, Leishmaniasis sp alter their virulence factors which may influence into to the subversive function of neutrophils at the early periods of the infection, interfering and / or blocking the generation of an adaptive effector immune response and promoting the propagation of the parasite, the central objective of this project. (AU)