Browsing by Author "Rafii, Shahin"

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    A Common Origin for B-1a and B-2 Lymphocytes in Clonal Pre- Hematopoietic Stem Cells
    (Elsevier, 2017-06-06) Hadland, Brandon K.; Varnum-Finney, Barbara; Mandal, Pankaj K.; Rossi, Derrick J.; Poulos, Michael G.; Butler, Jason M.; Rafii, Shahin; Yoder, Mervin C.; Yoshimoto, Momoko; Bernstein, Irwin D.; Pediatrics, School of Medicine
    Recent evidence points to the embryonic emergence of some tissue-resident innate immune cells, such as B-1a lymphocytes, prior to and independently of hematopoietic stem cells (HSCs). However, whether the full hematopoietic repertoire of embryonic HSCs initially includes these unique lineages of innate immune cells has been difficult to assess due to lack of clonal assays that identify and assess HSC precursor (pre-HSC) potential. Here, by combining index sorting of single embryonic hemogenic precursors with in vitro HSC maturation and transplantation assays, we analyze emerging pre-HSCs at the single-cell level, revealing their unique stage-specific properties and clonal lineage potential. Remarkably, clonal pre-HSCs detected between E9.5 and E11.5 contribute to the complete B cell repertoire, including B-1a lymphocytes, revealing a previously unappreciated common precursor for all B cell lineages at the pre-HSC stage and a second embryonic origin for B-1a lymphocytes.
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    Differentiation of human pluripotent stem cells to cells similar to cord-blood endothelial colony-forming cells
    (Nature Publishing Group, 2014-11) Prasain, Nutan; Lee, Man Ryul; Vemula, Sasidhar; Meador, Jonathan Luke; Yoshimoto, Momoko; Ferkowicz, Michael J.; Fett, Alexa; Gupta, Manav; Rapp, Brian M.; Saadatzadeh, Mohammad Reza; Ginsberg, Michael; Elemento, Olivier; Lee, Younghee; Voytik-Harbin, Sherry L.; Chung, Hyung Min; Hong, Ki Sung; Reid, Emma; O'Neill, Christina L.; Medina, Reinhold J.; Stitt, Alan W.; Murphy, Michael P.; Rafii, Shahin; Broxmeyer, Hal E.; Yoder, Mervin C.; Department of Pediatrics, IU School of Medicine
    The ability to differentiate human pluripotent stem cells into endothelial cells with properties of cord-blood endothelial colony-forming cells (CB-ECFCs) may enable the derivation of clinically relevant numbers of highly proliferative blood vessel-forming cells to restore endothelial function in patients with vascular disease. We describe a protocol to convert human induced pluripotent stem cells (hiPSCs) or embryonic stem cells (hESCs) into cells similar to CB-ECFCs at an efficiency of >10(8) ECFCs produced from each starting pluripotent stem cell. The CB-ECFC-like cells display a stable endothelial phenotype with high clonal proliferative potential and the capacity to form human vessels in mice and to repair the ischemic mouse retina and limb, and they lack teratoma formation potential. We identify Neuropilin-1 (NRP-1)-mediated activation of KDR signaling through VEGF165 as a critical mechanism for the emergence and maintenance of CB-ECFC-like cells.