EFFECTS OF INFECTION WITH RECOMBINANT ADENOVIRUS ON HUMAN VASCULAR ENDOTHELIAL AND SMOOTH-MUSCLE CELLS

The plasminogen activation (PA) system is involved in vascular remodel ling, Modulating its activity in vascular cells might be a way to inte rfere in processes such as angiogenesis and restenosis. Adenoviral vec tors have become a favourable tool for direct gene transfer into vascu lar cells. In the interest of using adenoviral vectors to modulate pla sminogen activator activity and endothelial and smooth muscle cell mig ration, we studied the effects of endothelial and smooth muscle cell t ransduction in vitro and in the umbilical vein ex vivo with a replicat ion-defective adenoviral vector containing the P-galactosidase gene (A dCMVLacZ). Segments of the umbilical vein were infected with AdCMVLacZ (10(9)-10(10)pfu/ml). After 48 h strong beta-galactosidase expression could be observed in the vessel wall, which was restricted to the end othelial layer. Although some heterogeneity in the transduction throug hout the vessel could be seen, P-galactosidase expression was detectab le for 21 days in explant. Infection of human vascular endothelial cel ls (HUVEC) with recombinant adenoviral vectors is a dose and time depe ndent process. To achieve 100% infection of cultured HUVEC after a 30 min infection period, adenovirus concentrations ranging from 10(10) to 5-10(10) pfu/ml are required. To achieve a similar infection of HUVSM C a concentration of 2-10(9) to 10(10) is sufficient. Expression of be ta-galactosidase can be detected for at least 14 days. Effects of tran sduction of HUVEC with AdCMVLacZ on proliferation, morphology and mono layer integrity were also studied. At high virus concentrations (> 10( 10) pfu/ml) an inhibitory effect on cell proliferation was detected an d cell morphology displayed many giant cells, often polynuclear, in th ese cultures. Infection of confluent HUVEC monolayers had, apart from a rapid transient effect during the infection procedure, little effect on the permeability of these monolayers, Only when the monolayers wer e infected using concentrations of 10(10) pfu/ml or more, an increase in permeability of these monolayers could be observed.