CD105 is a surface marker for receptor-targeted gene transfer into human long-term repopulating hematopoietic stem cells

Stem Cells Dev. 2015 Mar 15;24(6):714-23. doi: 10.1089/scd.2014.0455. Epub 2015 Jan 20.

Abstract

Hematopoietic stem cells (HSCs) are an important target cell population for gene therapy since they can reconstitute the entire hematopoietic system. HSC-enriched cell populations can be recognized based on cell surface marker expression, such as CD34, which is broadly expressed on immature and partially differentiated cells. In mice, co-expression of CD34 and CD105 was previously shown to be relatively more specific for the most immature, long-term repopulating HSCs. Here, we evaluated whether CD105, which is expressed on 30%-80% of CD34(+) cells, is a marker also for human long-term repopulating HSCs. Therefore, we tracked the mature progeny of CD34(+) cells transduced with the CD105-targeted lentiviral vector CD105-LV in xenotolerant mice. Transduction was blocked with soluble CD105 protein confirming specificity. Importantly, CD105-LV transduced human CD34(+) cells engrafted in NOD-scid IL2Rγ(-/-) mice with up to 20% reporter gene-positive cells detected long term in all human hematopoietic lineages in bone marrow (BM), spleen, and blood. In addition, competitive repopulation experiments in mice showed a superior engraftment of CD105-LV transduced CD34(+) cells in BM and spleen compared with cells transduced with a conventional nontargeted lentiviral vector. Thus, human CD34(+)/CD105(+) cells are enriched for early HSCs with high repopulating capacity. Targeting this cell population with CD105-LV offers a novel gene transfer strategy to reach high engraftment rates of transduced cells and highlights the applicability of receptor-targeted vectors to trace cell subsets offering an alternative to prospective isolation by surface markers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD / genetics
  • Antigens, CD / metabolism*
  • Antigens, CD34 / genetics
  • Antigens, CD34 / metabolism
  • Cell Differentiation
  • Endoglin
  • Gene Targeting
  • Hematopoietic Stem Cells / cytology
  • Hematopoietic Stem Cells / metabolism*
  • Humans
  • Interleukin Receptor Common gamma Subunit / genetics
  • Interleukin Receptor Common gamma Subunit / metabolism
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Stem Cell Transplantation / methods*

Substances

  • Antigens, CD
  • Antigens, CD34
  • ENG protein, human
  • Endoglin
  • Interleukin Receptor Common gamma Subunit
  • Receptors, Cell Surface