bioRxiv Science⌕ Search

Biology subjects

Mitnacht, M.

Publications and source records attributed to Mitnacht, M..

2 recordsLinked to original sources

Quantitative proteomics of infected macrophages reveals novel Leishmania virulence factors

Leishmaniasis is a major public health problem, causing diseases ranging from self-healing skin lesions to life-threatening chronic infections. Understanding how Leishmania parasites evade the host defense system is crucial for understanding the different manifestations of the disease and for improving diagnostic tools and drug development. We performed high-resolution proteome profiling of Leishmania spp. across three species during macrophage infection and identified distinct temporal expression patterns. Clustering analysis revealed unique protein expression profiles for each Leishmania species, whereas pairwise enrichment analysis revealed specific up- and downregulation patterns at different infection stages. Our results confirmed known virulence factors and highlighted new ones, demonstrating the utility of our dataset. We validated the dataset by showing that deletion of putative L. mexicana virulence factors resulted in reduced stage differentiation capacity and infectivity. This novel Leishmania infectome database (LInfDB) is available online for further exploration (https://butterlab.imb-mainz.de/LInfDB), providing a valuable resource for future research.

microbiology↗

The histone methyltransferase DOT1B is dispensable for stage differentiation and macrophage infection in Leishmania mexicana

Conserved histone methyltransferases of the DOT1 family are involved in replication regulation, cell cycle progression, stage differentiation and gene regulation in trypanosomatids. However, the specific functions of these enzymes depend on the host evasion strategies of the parasites. In his study, we investigated the role of DOT1B in Leishmania mexicana, focusing on life cycle progression and infectivity. In contrast to Trypanosoma brucei, in which DOT1B is essential for the differentiation of mammal-infective bloodstream forms to insect procyclic forms, L. mexicana DOT1B (LmxDOT1B) is not critical for the differentiation of promastigotes to amastigotes in vitro. Additionally, there are no significant differences in the ability to infect or differentiate in macrophages or sand fly vectors between the LmxDOT1B-depleted and control strains. These findings highlight the divergency of the function of DOT1B in these related parasites, suggesting genus-specific adaptations in the use of histone modifications for life cycle progression and host adaptation processes.

microbiology↗