Dual transcriptome analysis reveals differential gene expression modulation influenced by Leishmania arginase and host genetic background

Abstract

The outcome of Leishmania infection is strongly influenced by the host’s genetic background. BALB/c mice are susceptible to Leishmania infection, while C57BL/6 mice show discrete resistance. Central to the fate of the infection is the availability of l-arginine and the related metabolic processes in the host and parasite. Depending on l-arginine availability, nitric oxide synthase 2 (NOS2) of the host cell produces nitric oxide (NO) controlling the parasite growth. On the other hand, Leishmania can also use host l-arginine for the production of polyamines through its own arginase activity, thus favouring parasite replication. Considering RNA-seq data, we analysed the dual modulation of host and parasite gene expression of BALB/c or C57BL/6 mouse bone marrow-derived macrophages (BMDMs) after 4 h of infection with Leishmania amazonensis wild-type (La-WT) or L. amazonensis arginase knockout (La-arg-). We identified 12 641 host transcripts and 8282 parasite transcripts by alignment analysis with the respective Mus musculus and L. mexicana genomes. The comparison of BALB/c_La-arg- versus BALB/c_La-WT revealed 233 modulated transcripts, with most related to the immune response and some related to the amino acid transporters and l-arginine metabolism. In contrast, the comparison of C57BL/6_La-arg- vs. C57BL/6_La-WT revealed only 30 modulated transcripts, including some related to the immune response but none related to amino acid transport or l-arginine metabolism. The transcriptome profiles of the intracellular amastigote revealed 94 modulated transcripts in the comparison of La-arg-_BALB/c vs. La-WT_BALB/c and 45 modulated transcripts in the comparison of La-arg-_C57BL/6 vs. La-WT_C57BL/6. Taken together, our data present new insights into the impact of parasite arginase activity on the orchestration of the host gene expression modulation, including in the immune response and amino acid transport and metabolism, mainly in susceptible BALB/c-infected macrophages. Moreover, we show how parasite arginase activity affects parasite gene expression modulation, including amino acid uptake and amastin expression.

Metabolomic Reprogramming of C57BL/6-Macrophages during Early Infection with L. amazonensis

“…It also decreases putrescine, proline, ornithine, glutamic acid, S-adenosylmethionine, cystathionine, and N-carbamylarginine levels (Table 1 and Figure 6). Despite that, in a previous study, we did not find a modulation of the transcript levels involved in these metabolic pathways in the L. amazonensis infection context, comparing macrophages infected with La-WT and La-arg − [50].…”

“…L. amazonensis infection of BALB/c-macrophages increases host Cat2 and Arg1 transcripts, parasite arginine transporter (amino acid permease 3, AAP3), and parasite arginase [23]. Despite this, C57BL/6-macrophages infected with L. amazonensis did not modulate those genes [28,50].…”

miR-294 and miR-410 Negatively Regulate Tnfa, Arginine Transporter Cat1/2, and Nos2 mRNAs in Murine Macrophages Infected with Leishmania amazonensis

“…It is well-known that L-arginine metabolism contributes to macrophage polarization to the M1 or M2 phenotype. We have already demonstrated that macrophage infection with L. amazonensis promotes alterations to this scenario, leading to an M2-like macrophage phenotype in the early stages of infection [34]. To understand the impact of miRNAs on L-arginine metabolism in C57BL/6 macrophages, we focused on the analysis of transcript levels of two arginine transporters (Slc7a1 and Slc7a2-Cationic Amino Acids 1 and 2, respectively), Arginases 1 and 2 (Arg1 and Arg2), Nitric Oxide Synthase 2 (Nos2), and Ornithine Decarboxylase 1 (Odc1).…”

Advances in Understanding Leishmania Pathobiology: What Does RNA-Seq Tell Us?

“…Nitric oxide (NO) production is a defense mechanism used by macrophages being produced by nitric oxide synthase 2 (NOS2) in the presence of the amino acid L-arginine as substrate (Cunningham, 2002). Arginase on the other hand, reduces NO production by limiting the availability of L-arginine and favoring the survival of Leishmania in the macrophage (Camargo et al, 1978;Aoki et al, 2020). Aoki et al (2017) studied gene expression differences between L. amazonensis wildtype (La-WT) and L. amazonensis arginase knockout (Laarg − ) promastigotes and axenic amastigotes.…”

“…Arginase was found to upregulate membrane markers that affect parasite recognition, autophagy-related genes implicated in parasite differentiation and amastins that impact amastigote replication and survival, while modulating oxidative-stress related genes ( Aoki et al, 2019 ). The parasite’s arginase activity also appeared to modulate gene expression in the host macrophage including in the immune response and amino acid transport and metabolism ( Aoki et al, 2020 ).…”