1. Long-term hematopoietic stem cells trigger quiescence in Leishmania parasites.
- Author
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Dirkx, Laura, Van Acker, Sara, Nicolaes, Yasmine, Cunha, João Luís Reis, Ahmad, Rokaya, Hendrickx, Rik, Caljon, Ben, Imamura, Hideo, Ebo, Didier G., Jeffares, Daniel C., Sterckx, Yann G.-J., Maes, Louis, Hendrickx, Sarah, and Caljon, Guy
- Subjects
HEMATOPOIETIC stem cells ,STEM cell niches ,BONE marrow cells ,SAND flies ,PARASITES ,LEISHMANIA ,LEISHMANIA mexicana - Abstract
Addressing the challenges of quiescence and post-treatment relapse is of utmost importance in the microbiology field. This study shows that Leishmania infantum and L. donovani parasites rapidly enter into quiescence after an estimated 2–3 divisions in both human and mouse bone marrow stem cells. Interestingly, this behavior is not observed in macrophages, which are the primary host cells of the Leishmania parasite. Transcriptional comparison of the quiescent and non-quiescent metabolic states confirmed the overall decrease of gene expression as a hallmark of quiescence. Quiescent amastigotes display a reduced size and signs of a rapid evolutionary adaptation response with genetic alterations. Our study provides further evidence that this quiescent state significantly enhances resistance to treatment. Moreover, transitioning through quiescence is highly compatible with sand fly transmission and increases the potential of parasites to infect cells. Collectively, this work identified stem cells in the bone marrow as a niche where Leishmania quiescence occurs, with important implications for antiparasitic treatment and acquisition of virulence traits. Author summary: Quiescence and post-treatment relapse are crucial aspects of treatment failure across the microbiology field. This study shows that Leishmania infantum and L. donovani parasites rapidly enter into quiescence in both human and mouse bone marrow stem cells, but not in macrophages. Besides a reduced size, quiescent amastigotes show signs of a rapid evolutionary adaptation with notable genetic alterations. Transitioning through a quiescent state allows escape from treatment, efficient transmission by sand flies and the acquisition of an increased cellular infectivity. Transcriptional profiling of quiescent and non-quiescent parasites isolated from the stem cell niche confirmed a generalized transcriptional downregulation as a hallmark of quiescence. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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