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Quantification of Intracellular Growth Inside Macrophages is a Fast and Reliable Method for Assessing the Virulence of Leishmania Parasites
Published on: March 16, 2018
Expression of Network Medicine-Predicted Genes in Human Macrophages Infected with Leishmania major
Felipe Caixeta1, Vinicius Dantas Martins2,3, Amanda Braga Figueiredo4,5
1Programa Interunidades de Pós-Graduação em Bioinformática, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil.
Abstract:
Leishmania spp. commonly infects phagocytic cells of the immune system, particularly macrophages, employing various immune evasion strategies that enable their survival by altering the intracellular environment. In mammals, these parasites establish persistent infections by modulating gene expression in macrophages, thus interfering with immune signaling and response pathways, ultimately creating a favorable environment for the parasite's survival and reproduction. In this study, our objective was to use data mining and subsequent filtering techniques to identify the genes that play a crucial role in the infection process of Leishmania spp. We aimed to pinpoint genes that have the potential to influence the progression of Leishmania infection. To achieve this, we exploited prior, curated knowledge from major databases and constructed 16 datasets of human molecular information consisting of coding genes and corresponding proteins. We obtained over 400 proteins, identifying approximately 200 genes. The proteins coded by these genes were subsequently used to build a network of protein-protein interactions, which enabled the identification of key players; we named this set Predicted Genes. Then, we selected approximately 10% of Predicted Genes for biological validation. THP-1 cells, a line of human macrophages, were infected with Leishmania major in vitro for the validation process. We observed that L. major has the capacity to impact crucial genes involved in the immune response, resulting in macrophage inactivation and creating a conducive environment for the survival of Leishmania parasites.
Insights
This study identifies key genes involved in Leishmania parasite infection by analyzing protein interactions in macrophages. These findings reveal how Leishmania manipulates host immune cells for survival.
Area of Science:
- Immunology
- Parasitology
- Genetics
Background:
- Leishmania parasites infect macrophages, evading immune responses.
- Persistent infections are established by modulating host gene expression.
- Understanding parasite-host interactions is crucial for developing treatments.
Purpose of the Study:
- Identify genes critical for Leishmania spp. infection.
- Determine genes influencing Leishmania infection progression.
- Investigate parasite-host molecular mechanisms.
Main Methods:
- Data mining of curated databases.
- Construction of human molecular information datasets.
- Protein-protein interaction network analysis.
- In vitro infection of THP-1 macrophage cells with Leishmania major.
Main Results:
- Identified approximately 200 key genes (Predicted Genes) involved in Leishmania infection.
- Protein-protein interaction network analysis pinpointed crucial players.
- Biological validation confirmed Leishmania major impacts immune response genes in macrophages.
- Macrophage inactivation observed, favoring parasite survival.
Conclusions:
- Leishmania parasites actively manipulate host macrophage gene expression.
- Identified genes offer potential targets for therapeutic intervention.
- Understanding these molecular interactions is key to combating Leishmania infections.

