To evaluate the strategy for potentially treating respiratory disorders with genetically modified T-lymphocytes, the interleukin-2 (IL-2)-dependent murine T-cell line, CTLL2, was genetically altered with the Escherichia coli β-galactosidase (β-gal) gene (lacZ) in vitro with a retroviral vector and the modified T-cells were transplanted directly to the respiratory epithelial surface of syngeneic C57Bl/6 mice. Southern and Northern analyses confirmed that the neomycin-selected modified T-cells contained and expressed the lacZ gene. The fate of the modified T-cells (CTLL2/ lacZ) was followed by flow cytometry with T-cell surface marker Thy 1.2 and fluorescent β-gal analysis. One day after transplantation (7.5 × 105 CTLL2/lacZ T-cells/g of body weight), 95 ± 3% of the Thy1.2+ T-cells recovered from respiratory epithelial lining fluid (ELF) were β-gal+. Importantly, the modified T-cells remained in the lung for some time; at 3 days, Thy 1.2+ β-gal+ T-cells represented 63 ± 12% of ELF Thy1.2+ T-cells and 59 ± 6% of Thy1.2+ T-cells recovered from the whole lung. At 7 days, 33 ± 8% of the Thy 1.2+ cells in ELF and 75 ± 6% of the Thy1.2+ cells in whole lung were Thy1.2+ β-gal+. In contrast, the proportion of the Thy1.2+ β-gal+ T-cells in the spleen, the major extrapulmonary lymphatic organ, never rose above 3 ± 1% of the total Thy1.2+ cells. The number of Thy1.2+ β-gal+ T-cells in the lung could be modified by the systemic administration of IL-2, with whole lung Thy1.2+ β-gal+ T-cells increasing 4.6-fold 3 days after transplantation, compared with non-IL-2-treated animals. These studies suggest that direct transplantation of genetically modified T-cells into the lung is feasible and represents a viable strategy for lung-specific gene transfer.
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - Sep 25 1991|