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- Hildebrandt, Franziska, 1994-, et al.
(author)
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scDual-Seq of Toxoplasma gondii-infected mouse BMDCs reveals heterogeneity and differential infection dynamics
- 2023
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In: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 14
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Journal article (peer-reviewed)abstract
- Dendritic cells and macrophages are integral parts of the innate immune system and gatekeepers against infection. The protozoan pathogen, Toxoplasma gondii, is known to hijack host immune cells and modulate their immune response, making it a compelling model to study host-pathogen interactions. Here we utilize single cell Dual RNA-seq to parse out heterogeneous transcription of mouse bone marrow-derived dendritic cells (BMDCs) infected with two distinct genotypes of T. gondii parasites, over multiple time points post infection. We show that the BMDCs elicit differential responses towards T. gondii infection and that the two parasite lineages distinctly manipulate subpopulations of infected BMDCs. Co-expression networks define host and parasite genes, with implications for modulation of host immunity. Integrative analysis validates previously established immune pathways and additionally, suggests novel candidate genes involved in host-pathogen interactions. Altogether, this study provides a comprehensive resource for characterizing host-pathogen interplay at high-resolution.
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| 2. |
- Khalili, Dilan, 1988-, et al.
(author)
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Single-cell sequencing of tumor-associated macrophages in a Drosophila model
- 2023
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In: Frontiers in Immunology. - 1664-3224. ; 14
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Journal article (peer-reviewed)abstract
- Introduction: Tumor-associated macrophages may act to either limit or promote tumor growth, yet the molecular basis for either path is poorly characterized.Methods: We use a larval Drosophila model that expresses a dominant-active version of the Ras-oncogene (RasV12) to study dysplastic growth during early tumor progression. We performed single-cell RNA-sequencing of macrophage-like hemocytes to characterize these cells in tumor- compared to wild-type larvae. Hemocytes included manually extracted tumor-associated- and circulating cells.Results and discussion: We identified five distinct hemocyte clusters. In addition to RasV12 larvae, we included a tumor model where the activation of effector caspases was inhibited, mimicking an apoptosis-resistant setting. Circulating hemocytes from both tumor models differ qualitatively from control wild-type cells—they display an enrichment for genes involved in cell division, which was confirmed using proliferation assays. Split analysis of the tumor models further reveals that proliferation is strongest in the caspase-deficient setting. Similarly, depending on the tumor model, hemocytes that attach to tumors activate different sets of immune effectors—antimicrobial peptides dominate the response against the tumor alone, while caspase inhibition induces a shift toward members of proteolytic cascades. Finally, we provide evidence for transcript transfer between hemocytes and possibly other tissues. Taken together, our data support the usefulness of Drosophila to study the response against tumors at the organismic level.
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| 3. |
- Mohammed, Mubasher, Msc, et al.
(author)
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Single-cell transcriptomics reveals transcriptional programs underlying male and female cell fate during Plasmodium falciparum gametocytogenesis
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Other publication (other academic/artistic)abstract
- The Apicomplexa constitute a large phylum of parasitic protozoa with complex life cycles that typically include meiotic sex. The life cycle of the malaria parasite, Plasmodium falciparum, includes obligate transition and stage development between a human and mosquito host. Asexual parasite replication in the human erythrocytes is followed by differentiation which leads to the formation of a precursor gamete stage, referred to as gametocytes. The gametocyte stage is solely responsible for malaria transmission into the mosquito vector where gamete fusion followed by meiosis occurs. How the parasite differentiates into male and female gametocytes in the absence of sex chromosomes largely remains an open question. Here we combine FACS-based cell enrichment of a gametocyte reporter line followed by single-cell RNA-seq, to enable targeted characterization of the entire gametocyte developmental stage. Our data defines differential transcriptional programs during male and female gametocyte development and highlights a bifurcation point for sexual cell fate. We perform prediction analyses of novel candidate driver genes underlying P. falciparum male and female lineage development. Our data indicate that a large panel of genes linked to the inner membrane complex, known to be involved in morphological life cycle changes, appears to be uniquely expressed in the female gametocyte lineage. Additionally, we delineate the timing of expression of members of the ApiAP2 family of transcription factors and predict their specificity in male and female P. falciparum gametocyte development. A motif-driven gene regulatory network analysis indicates a major role for AP2-G5 in downstream gene regulation along the male lineage developmental trajectory. In total, we anticipate that this study provides the malaria community with an important resource for the development of transmission-blocking intervention strategies.
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| 4. |
- Mohammed, Mubasher, Msc, et al.
(author)
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Single-Cell Transcriptomics To Define Plasmodium falciparum Stage Transition in the Mosquito Midgut
- 2023
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In: Microbiology Spectrum. - : American Society for Microbiology. - 2165-0497. ; 11:2
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Journal article (peer-reviewed)abstract
- Malaria inflicts the highest rate of morbidity and mortality among the vector-borne diseases. The dramatic bottleneck of parasite numbers that occurs in the gut of the obligatory mosquito vector provides a promising target for novel control strategies. Using single-cell transcriptomics, we analyzed Plasmodium falciparum development in the mosquito gut, from unfertilized female gametes through the first 20 h after blood feeding, including the zygote and ookinete stages. This study revealed the temporal gene expression of the ApiAP2 family of transcription factors and of parasite stress genes in response to the harsh environment of the mosquito midgut. Further, employing structural protein prediction analyses, we found several upregulated genes predicted to encode intrinsically disordered proteins (IDPs), a category of proteins known for their importance in regulation of transcription, translation, and protein-protein interactions. IDPs are known for their antigenic properties and may serve as suitable targets for antibody- or peptide-based transmission suppression strategies. In total, this study uncovers the P. falciparum transcriptome from early to late parasite development in the mosquito midgut, inside its natural vector, which provides an important resource for future malaria transmission-blocking initiatives.
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