ABSTRACT
<p><b>OBJECTIVE</b>To investigate the protective effects on allografts and the possible mechanism of adeno-associated heme-oxygenase-1 (AdHO-1) gene therapy against chronic rejection injury.</p><p><b>METHODS</b>Ex vivo AdHO-1 gene therapy was performed in vascular and renal transplantation models. The structure and function, the expression of therapeutic genes and proteins, and the immune modulation were analyzed.</p><p><b>RESULTS</b>AdHO-1 gene therapy protected renal transplant against chronic rejection, but the effect was not as remarkable as that in vascular transplant. The transfected empty vehicle aggravated chronic rejection damage in renal transplantation. AdHO-1 decreased the infiltration of macrophages and CD4(+) T cells.</p><p><b>CONCLUSIONS</b>AdHO-1 gene therapy can lessen damage of chronic rejection in allografts. It plays roles by protecting transplants, down-regulating immune response and inducing immune deviation.</p>