Transcriptomic analysis in human macrophages infected with therapeutic failure clinical isolates of Leishmania infantum

Leishmaniasis is one of the neglected tropical diseases with a worldwide distribution, affecting humans and animals. In the absence of an effective vaccine, current treatment is through the use of chemotherapy; however, existing treatments have frequent appearance of drug resistance and therapeutic failure (TF). The identification of factors that contribute to TF in leishmaniasis will provide the basis for a future therapeutic strategy more efficient for the control of this disease. In this manuscript, we have evaluated the transcriptomic changes in the host cells THP-1 after infection with clinical Leishmania infantum isolates from leishmaniasis patients with TF. Our results show that distinct L. infantum isolates differentially modulate host cell response, inducing phenotypic changes that probably may account for parasite survival and TF of patients. Analysis of differential expression genes (DEG), with a statistical significance threshold of a fold change > 2 and a FDR value < 0.05, revealed a different number of DEG according to the Leishmania line. Globally, there was a similar number of genes up- and downregulated in all the infected host THP-1 cells, with exception of Hi-L2221 that showed a higher number of downregulated DEG. We observed a total of 58 DEG commonly modulated in all infected host cells, including up- (log2FC > 1) and downregulated (log2FC < -1) genes. Based on the results obtained from the analysis of RNA-seq, Volcano-plot and GO enrichment analysis, we identified the most significant transcripts of relevance for their possible contribution to the TF observed in patients with leishmaniasis.