Gene delivery into the renal glomerulus by transfer of genetically engineered, autologous mesangial cells.

To obviate the problem of rejection in situations where cells are used as vectors for gene delivery, the feasibility of using autologous mesangial cells cultured from renal biopsy specimens was studied for the purpose of gene transfer into the glomerulus. Using the calcium-phosphate co-precipitation method, a reporter gene which encodes bacterial beta-galactosidase was introduced into cultured mesangial cells derived from renal biopsy tissue of rats. Stable transfectants were established in the presence of a selection drug and then transferred back into the contralateral kidneys of the same animals via renal artery injection. Among 5 rats tested, expression of beta-galactosidase was detected in the isolated glomeruli from 4 injected kidneys. One week after cell injection, 31 +/- 13% of the glomeruli showed positive X-gal (5-bromo-4-chloro-3-indolyl beta- D-galactopyranoside) staining, indicating expression of the transferred gene. The use of autologous mesangial cells from biopsy specimens is thus realistic and would be useful to obviate the risk of rejection in the mesangial cell vector system.