Retroviral-Mediated Gene Transfer of the Leukocyte Integrin CD18
Into Peripheral Blood CD34+ Cells Derived From a
Patient With Leukocyte Adhesion Deficiency Type 1
Thomas R. Bauer Jr,
Barbara R. Schwartz,
W. Conrad Liles,
Hans D. Ochs, and
Dennis D. Hickstein
From the Medical Research Service, VA Puget Sound Health Care System,
Seattle; and the Divisions of Oncology, Hematology, Allergy and
Infectious Diseases, Pediatrics, and Molecular Medicine, University of
Washington School of Medicine, Seattle.
Leukocyte adhesion deficiency or LAD is a congenital
immunodeficiency disease characterized by recurrent bacterial
infections in which the leukocytes from affected children fail to
adhere to endothelial cells and migrate to the site of infection due to
heterogeneous defects in the leukocyte integrin CD18 subunit. To assess
the feasibility of human gene therapy of LAD, we transduced granulocyte
colony-stimulating factor (G-CSF)-mobilized, CD34+
peripheral blood stem cells derived from a patient with the severe form
of LAD using supernatant from the retroviral vector PG13/LgCD18. The
highest transduction frequencies (31%) were found after exposure of
the cells to retroviral vector on a substrate of recombinant fibronectin fragment CH-296 in the presence of growth factors interleukin-3 (IL-3), IL-6, and stem cell factor. When the phenotype of
the transduced cells was monitored by fluorescence-activated cell
sorting following in vitro differentiation with growth
factors G-CSF and granulocyte-macrophage CSF (GM-CSF), CD11a surface
expression was detected immediately after transduction. CD11b and CD11c
were expressed at low levels immediately following transduction, but increased over 3 weeks in culture. Adhesion of the transduced cells was
nearly double that of nontransduced cells in a cell adhesion assay
using human umbilical vein endothelial cells. Transduced cells also
demonstrated the ability to undergo a respiratory burst in response to
opsonized zymosan, a CD11/CD18-dependent ligand. These experiments show
that retrovirus-mediated gene transfer of the CD18 subunit complements
the defect in LAD CD34+ cells resulting in CD11/CD18
surface expression, and that the differentiated myelomonocytic cells
derived from the transduced LAD CD34+ cells display
CD11/CD18-mediated adhesion function. These results indicate that ex
vivo gene transfer of CD18 into LAD CD34+ cells, followed
by re-infusion of the transduced cells, may represent a therapeutic
approach to LAD.
Blood, Vol. 91 No. 5 (March 1), 1998:
pp. 1520-1526
© 1998 by The American Society of Hematology.
