Dual Transcriptomics in Trophoblastic cells infected by Trypanosoma cruzi
Congenital transmission of Trypanosoma cruzi represents a significant global health challenge, driven by complex interactions between the parasite, the mother, the placenta, and the fetus. While the precise molecular mechanisms enabling T. cruzi to cross the placenta remain largely unknown, its interaction with trophoblastic cells is critical for infection. Previous studies have identified substantial gene expression changes in the placenta during infection, particularly in immune response pathways. However, specific molecular interactions remain poorly understood, especially for T. cruzi Discrete Typing Unit I (TcI), which is prevalent in Colombia and Venezuela but underexplored in congenital transmission. This study aimed to investigate the transcriptional remodeling of both the host and T. cruzi (TcI) during infection of human trophoblastic cells, shedding light on the molecular mechanisms underlying congenital Chagas disease transmission. We used two T. cruzi TcI strains— MHOM/CO/01/DA and MHOM/CO/04/MG—purified as cell-derived trypomastigotes from infected VERO cells to infect BeWo trophoblast cells. Infections were assessed through infection curves and statistical analyses. RNA was extracted at 72 and 120 hours post-infection and sequenced using Illumina NovaSeq. Differential expression analysis, gene ontology evaluation, and signaling pathway reconstruction were performed. The MG strain exhibited higher invasion, replication, and trypomastigote production compared to the DA strain. Transcriptomic analysis identified 129 downregulated and 28 upregulated genes in the parasite at both time points. Notably, alterations in multigene families encoding surface proteins—key for immune evasion and life cycle progression— were observed. In trophoblastic cells, upregulation of histones and ribonucleoproteins suggested chromatin reorganization and activation of DNA repair pathways. Conversely, downregulation of RNA splicing-related genes may impair RNA maturation and weaken host defenses. At 120 hours post-infection, upregulation of the necroptosis pathway indicated a shift toward regulated cell death  and a pro-inflammatory response. Our findings reveal that T. cruzi TcI infection induces extensive transcriptional remodeling in both the parasite and the host. These changes disrupt cellular signaling pathways, alter transcriptional regulation, and modify the genomic structure of trophoblastic cells, facilitating parasite adaptation and immune evasion. The resulting alterations in host cell function may compromise essential processes required for tissue integrity and homeostasis, potentially contributing to the pathogenesis of congenital Chagas disease.