Inverse targeting of retroviral vectors : Selective gene transfer in a mixed population of hematopoietic and nonhematopoietic cells

• Published in: Blood Vol. 91; no. 5; pp. 1802 - 1809
• Main Authors: FIELDING, A. K, MAURICE, M, MORLING, F.-L, COSSET, F.-L, RUSSELL, S. J
• Format: Journal Article
• Language: English
• Published: Washington, DC The Americain Society of Hematology 01.03.1998
• Subjects: 3T3 Cells; Animals; Biological and medical sciences; Biotechnology; Cell Line; Epidermal Growth Factor - genetics; Epidermal Growth Factor - metabolism; ErbB Receptors - metabolism; Factor Xa - metabolism; Fundamental and applied biological sciences. Psychology; Gene Targeting; Gene Transfer Techniques; Genetic engineering; Genetic technics; Genetic Vectors; Hematopoietic Stem Cells - metabolism; Humans; Methods. Procedures. Technologies; Mice; Neoplasms - metabolism; Proto-Oncogene Proteins c-kit - analysis; Proto-Oncogene Proteins c-kit - metabolism; Recombinant Fusion Proteins; Retroviridae - genetics; Stem Cell Factor - genetics; Vectors (cloning, transfer, expression). Insertion sequences and transposons; Human; Targeting; Enzyme; Stem cell; Cytokine; Rodentia; Hematopoietic cell; Retroviridae; Inversion; Genetic transfer; Virus; Vertebrata; Mammalia; Mouse; Glycosidases; Animal; Hydrolases; Genetic engineering; Transduction; Mast cell growth factor; O-Glycosidases; Vector; β-Galactosidase; Growth factor
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V91.5.1802

We previously reported that retroviral vectors displaying epidermal growth factor (EGF) as part of a chimeric envelope glycoprotein are sequestered upon binding to EGF receptor (EGFR)-positive target cells, leading to loss of infectivity. In the current study, we have displayed stem cell factor (SCF) on beta-galactosidase-transducing ecotropic and amphotropic retroviral vector particles as a factor Xa protease-cleavable N-terminal extension of the envelope glycoprotein. Viral incorporation of the SCF chimeric envelopes was demonstrated by immunoblotting of pelleted virions and their specific attachment to Kit receptors was demonstrated by flow cytometry. Gene transfer studies showed that when SCF was displayed on an amphotropic envelope, the infectivity of the SCF-displaying vectors was selectively inhibited on Kit-expressing cells, but could be restored by adding soluble SCF to block the Kit receptors or by cleaving the displayed SCF domain from the vector particles with factor Xa protease. The host range properties of EGF-displaying and SCF-displaying vectors were then compared in cell mixing experiments. When EGFR-positive cancer cells and Kit-positive hematopoietic cells were mixed and exposed to the different engineered vector particles, the cancer cells were selectively transduced by the SCF-displaying vector and the hematopoietic cells were selectively transduced by the EGF-displaying vector. Retroviral display of polypeptide growth factors can therefore provide the basis for a novel inverse targeting strategy with potential use for selective transduction of hematopoietic or nonhematopoietic cells (eg, cancer cells) in a mixed cell population.