Transcriptional Profiling of Macrophages Reveals Distinct Parasite Stage-driven Signatures During Early Infection by Leishmania Donovani

Abstract

Macrophages undergo swift changes in mRNA abundance upon pathogen invasion. Herein we describe early remodelling of the macrophage transcriptome during infection by amastigotes or promastigotes of Leishmania donovani. Approximately 10% - 16% of host mRNAs were differentially modulated in L. donovani-infected macrophages when compared to uninfected controls. This response was partially stage-specific as a third of changes in mRNA abundance were either exclusively driven by one of the parasite forms or significantly different between them. Gene ontology analyses identified categories associated with immune functions (e.g. antigen presentation and leukocyte activation) among significantly downregulated mRNAs while cytoprotective-related categories (e.g. DNA repair and apoptosis inhibition) were enriched in upregulated transcripts during amastigote infection. Interestingly a combination of upregulated (e.g. cellular response to IFNβ) and repressed (e.g. leukocyte activation, chemotaxis) immune-related transcripts were overrepresented in the promastigote-infected dataset. In addition, Ingenuity Pathway Analysis (IPA®) coupled specific mRNA subsets with a number of upstream transcriptional regulators predicted to be modulated in macrophages infected with L. donovani amastigotes (e.g. STAT1 inhibition) or promastigotes (e.g. NRF2, IRF3, and IRF7 activation). Overall, our results indicate that early parasite stage-driven transcriptional remodelling in macrophages contributes to orchestrate both protective and deleterious host cell responses during L. donovani infection.

Single cell profiling reveals strain-specific differences in myeloid inflammatory potential in the rat liver

“…The DA-specific TFs Nucks1, Runx1, Mitf, and Gata1 have more diverse functions 56,[58][59][60] (Figure 3E, Figure S16, Table S5). For example, Nucks1 and Runx1 are implicated in immunomodulation, while Gata1 and Mitf are associated with cell fate and differentiation [61][62][63][64] .…”