Knockdown of Host Antioxidant Defense Genes Enhances the Effect of Glucantime on Intracellular Leishmania braziliensis in Human Macrophages

• Published in: Antimicrobial agents and chemotherapy Vol. 61; no. 7
• Main Authors: Téllez, Jair, Romero, Ibeth, Soares, Maurilio José, Steindel, Mario, Romanha, Alvaro José
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01-07-2017
• Subjects: Leishmania braziliensis; Macrophages; Mechanisms of Resistance; Meglumine; Organometallic Compounds; Leishmania braziliensis; host-pathogen interaction; human leishmaniasis; GSS; GSTP1; ABCB5; Glucantime
• ISSN: 0066-4804; 1098-6596
• DOI: 10.1128/AAC.02099-16

Leishmaniasis is a neglected tropical disease that affects millions of people worldwide and represents a major public health problem. Information on protein expression patterns and functional roles within the context of
-infected human monocyte-derived macrophages (MDMs) under drug treatment conditions is essential for understanding the role of these cells in leishmaniasis treatment. We analyzed functional changes in the expression of human MDM genes and proteins during
infection by
and treatment with Glucantime (Sb
), using quantitative PCR (qPCR) arrays, Western blotting, confocal microscopy, and small interfering RNA (siRNA) human gene inhibition assays. Comparison of the results from gene transcription and protein expression analyses revealed that glutathione
-transferase π1 (GSTP1), glutamate-cysteine ligase modifier subunit (GCLM), glutathione reductase (GSR), glutathione synthetase (GSS), thioredoxin (TRX), and ATP-binding cassette, subfamily B, member 5 (ABCB5), were strongly upregulated at both the mRNA and protein levels in human MDMs that were infected and treated, compared to the control group. Subcellular localization studies showed a primarily phagolysosomal location for the ABCB5 transporter, indicating that this protein may be involved in the transport of Sb
By inducing a decrease in
intracellular survival in THP-1 macrophages, siRNA silencing of
,
, and
resulted in an increased leishmanicidal effect of Sb
exposure
Our results suggest that human MDMs infected with
and treated with Sb
express increased levels of genes participating in antioxidant defense, whereas our functional analyses provide evidence for the involvement of human MDMs in drug detoxification. Therefore, we conclude that GSS, GSTP1, and ABCB5 proteins represent potential targets for enhancing the leishmanicidal activity of Glucantime.