Taking the good out of the bad: lentiviral-based gene therapy of the hemoglobinopathies.

Sickle cell disease and beta-thalassemia are excellent candidates for gene therapy since transfer of a single gene into hematopoietic stem cells should theoretically elicit a therapeutic response. Initial attempts at gene therapy of these hemoglobinopathies have proved unsuccessful due to limitations of available gene transfer vectors. With the extensive research on human immunodeficiency virus-1 due to the acquired immune deficiency syndrome pandemic, researchers have realized that this lentivirus, engineered to be devoid of any pathogenic elements, can be an effective gene transfer vector. This review discusses the gene therapy strategy for the hemoglobinopathies and outlines why lentiviral-derived vectors are particularly suited for this type of application, keeping past failures at gene therapy of these hemoglobinopathies in mind. Development, improvement, and methods for preparation of lentiviral-derived vectors are examined. Recently published results of successful gene therapy treatment of beta-thalassemic and sickle cell diseased mice using lentiviral-derived vectors are described. Finally, criticisms and future directions of lentiviral-based biotechnology are considered.