Impact of reactive oxygen species (ROS) on the control of parasite loads and inflammation in Leishmania amazonensis infection

Roma, Eric Henrique; Pereira de Macêdo, Juan; Goes, Grazielle Ribeiro; Gonçalves, Juliana Lauar; Castro, Waldionê de; Cisalpino, Daniel; Vieira, Leda Quercia (2016). Impact of reactive oxygen species (ROS) on the control of parasite loads and inflammation in Leishmania amazonensis infection. Parasites & Vectors, 9(1), p. 193. BioMed Central 10.1186/s13071-016-1472-y

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Background: Reactive oxygen species (ROS) protect the host against a large number of pathogenic microorganisms. ROS have different effects on parasites of the genus Leishmania: some parasites are susceptible to their action, while others seem to be resistant. The role of ROS in L. amazonensis infection in vivo has not been addressed to date. Methods: In this study, C57BL/6 wild-type mice (WT) and mice genetically deficient in ROS production by phagocytes (gp91phox−/− ) were infected with metacyclic promastigotes of L. amazonensis to address the effect of ROS in parasite control. Inflammatory cytokines, parasite loads and myeloperoxidase (MPO) activity were evaluated. In parallel, in vitro infection of peritoneal macrophages was assessed to determine parasite killing, cytokine, NO and ROS production. Results: In vitro results show induction of ROS production by infected peritoneal macrophages, but no effect in parasite killing. Also, ROS do not seem to be important to parasite killing in vivo, but they control lesion sizes at early stages of infection. IFN-γ, TNF-α and IL-10 production did not differ among mouse strains. Myeloperoxidase assay showed augmented neutrophils influx 6 h and 72 h post - infection in gp91phox−/− mice, indicating a larger inflammatory response in gp91phox−/− even at early time points. At later time points, neutrophil numbers in lesions correlated with lesion size: larger lesions in gp91phox−/− at earlier times of infection corresponded to larger neutrophil infiltrates, while larger lesions in WT mice at the later points of infection also displayed larger numbers of neutrophils. Conclusion: ROS do not seem to be important in L. amazonensis killing, but they regulate the inflammatory response probably by controlling neutrophils numbers in lesions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Molecular Plant Physiology
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Pereira de Macêdo, Juan

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

1756-3305

Publisher:

BioMed Central

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

18 May 2016 16:36

Last Modified:

18 May 2017 08:47

Publisher DOI:

10.1186/s13071-016-1472-y

PubMed ID:

27056545

Uncontrolled Keywords:

Leishmania amazonensis, ROS, NOX2, Neutrophils, Inflammation

BORIS DOI:

10.7892/boris.82030

URI:

https://boris.unibe.ch/id/eprint/82030

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