Mobilized peripheral blood CD34+ cells express more amphotropic retrovirus receptor than bone marrow CD34+ cells

Marco Bregni, Massimo Di Nicola, Salvatore Siena, Nadia Belli, Marco Milanesi, Suzy Shammah, Fernando Ravagnani, Alessandro M. Gianni

Research output: Contribution to journalArticlepeer-review

Abstract

Background and Objective. The increased susceptibility to gene transfer by amphotropic retroviral vectors of mobilized peripheral blood (PB) CD34+ cells compared to their bone marrow (BM) counterparts may depend, among other factors, on the level of expression of the amphotropic receptor on the progenitor cell. Using a previously described flow cytometry strategy, we have studied retrovirus binding to mobilized CD34+ cells, derived from cancer patients treated with high-dose chemotherapy and growth factor(s), that are efficiently transduced by N2 retro-virus vector. Design and Methods. We measured the binding of the retrovirus to the cells using a rat monoclonal antibody reactive with the gp70 envelope glycoprotein, common to all replication-defective amphotropic retroviruses. Antibody-virus-cell complexes were indirectly labeled and analyzed by flow cytometry. We compared the binding of PA317-N2 vector to CD34+ cells derived from steady-state BM, steady-state PB and mobilized PB from cancer patients treated with high-dose chemotherapy and cytokine. Results. The fluorescence intensity of mobilized CD34+ cells was approximately one log higher than that of steady-state BM or PB CD34+ cells, indicating that the expression of the amphotropic receptor was increased. Moreover, the virus binding was proportional to the gene transfer rate, as assessed by G418 resistance into mobilized PB-derived CFU- GM. The increase in fluorescence intensity appeared to be restricted to CD34+ cell subset, neither CD2+ nor CD14+ cells bound the virus in an appreciable amount. Interpretation and Conclusions. Virus binding, as assessed by indirect immunofluorescence assay, is increased in mobilized CD34+ cells. The increased binding may contribute to their high susceptibility to retrovirus vector infection.

Original languageEnglish
Pages (from-to)204-208
Number of pages5
JournalHaematologica
Volume83
Issue number3
Publication statusPublished - Mar 1998

Keywords

  • Amphotropic receptor
  • CD34
  • Gene transfer
  • Retroviruses
  • Stem cells

ASJC Scopus subject areas

  • Hematology

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