Person:
Lobbardi, Riadh

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Lobbardi

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Riadh

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Lobbardi, Riadh

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Now showing 1 - 3 of 3
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    Optimized cell transplantation using adult rag2 mutant zebrafish
    (2014) Tang, Qin; Abdelfattah, Nouran S.; Blackburn, Jessica S.; Moore, John C.; Martinez, Sarah A.; Moore, Finola E.; Lobbardi, Riadh; Tenente, Inês M.; Ignatius, Myron S.; Berman, Jason N.; Liwski, Robert S.; Houvras, Yariv; Langenau, David
    Cell transplantation into adult zebrafish has lagged behind mouse due to the lack of immune compromised models. Here, we have created homozygous rag2E450fs mutant zebrafish that have reduced numbers of functional T and B cells but are viable and fecund. Mutant fish engraft zebrafish muscle, blood stem cells, and cancers. rag2E450fs mutant zebrafish are the first immune compromised zebrafish model that permits robust, long-term engraftment of multiple tissues and cancer.
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    Single-cell imaging of normal and malignant cell engraftment into optically clear prkdc-null SCID zebrafish
    (The Rockefeller University Press, 2016) Moore, John C.; Tang, Qin; Yordán, Nora Torres; Moore, Finola E.; Garcia, Elaine; Lobbardi, Riadh; Ramakrishnan, Ashwin; Marvin, Dieuwke L.; Anselmo, Anthony; Sadreyev, Ruslan; Langenau, David
    Cell transplantation into immunodeficient mice has revolutionized our understanding of regeneration, stem cell self-renewal, and cancer; yet models for direct imaging of engrafted cells has been limited. Here, we characterize zebrafish with mutations in recombination activating gene 2 (rag2), DNA-dependent protein kinase (prkdc), and janus kinase 3 (jak3). Histology, RNA sequencing, and single-cell transcriptional profiling of blood showed that rag2 hypomorphic mutant zebrafish lack T cells, whereas prkdc deficiency results in loss of mature T and B cells and jak3 in T and putative Natural Killer cells. Although all mutant lines engraft fluorescently labeled normal and malignant cells, only the prkdc mutant fish reproduced as homozygotes and also survived injury after cell transplantation. Engraftment into optically clear casper, prkdc-mutant zebrafish facilitated dynamic live cell imaging of muscle regeneration, repopulation of muscle stem cells within their endogenous niche, and muscle fiber fusion at single-cell resolution. Serial imaging approaches also uncovered stochasticity in fluorescently labeled leukemia regrowth after competitive cell transplantation into prkdc mutant fish, providing refined models to assess clonal dominance and progression in the zebrafish. Our experiments provide an optimized and facile transplantation model, the casper, prkdc mutant zebrafish, for efficient engraftment and direct visualization of fluorescently labeled normal and malignant cells at single-cell resolution.
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    Publication
    Single-cell transcriptional analysis of normal, aberrant, and malignant hematopoiesis in zebrafish
    (The Rockefeller University Press, 2016) Moore, Finola E.; Garcia, Elaine; Lobbardi, Riadh; Jain, Esha; Tang, Qin; Moore, John C.; Cortes, Mauricio; Molodtsov, Aleksey; Kasheta, Melissa; Luo, Christina C.; Garcia, Amaris J.; Mylvaganam, Ravi; Yoder, Jeffrey A.; Blackburn, Jessica S.; Sadreyev, Ruslan; Ceol, Craig J.; North, Trista; Langenau, David
    Hematopoiesis culminates in the production of functionally heterogeneous blood cell types. In zebrafish, the lack of cell surface antibodies has compelled researchers to use fluorescent transgenic reporter lines to label specific blood cell fractions. However, these approaches are limited by the availability of transgenic lines and fluorescent protein combinations that can be distinguished. Here, we have transcriptionally profiled single hematopoietic cells from zebrafish to define erythroid, myeloid, B, and T cell lineages. We also used our approach to identify hematopoietic stem and progenitor cells and a novel NK-lysin 4+ cell type, representing a putative cytotoxic T/NK cell. Our platform also quantified hematopoietic defects in rag2E450fs mutant fish and showed that these fish have reduced T cells with a subsequent expansion of NK-lysin 4+ cells and myeloid cells. These data suggest compensatory regulation of the innate immune system in rag2E450fs mutant zebrafish. Finally, analysis of Myc-induced T cell acute lymphoblastic leukemia showed that cells are arrested at the CD4+/CD8+ cortical thymocyte stage and that a subset of leukemia cells inappropriately reexpress stem cell genes, including bmi1 and cmyb. In total, our experiments provide new tools and biological insights into single-cell heterogeneity found in zebrafish blood and leukemia.