Vectors - A Virus to deliver Genes

Herpes virus as a gene therapy vector

HSV can be further modified so that it no longer has the ability to kill cells. Such viruses can be used as delivery vehicles to introduce additional genetic material into host cells. This strategy can be used for therapeutic purposes to produce proteins which are for some reason deficient or abnormal in the disease process in question.

For example, some types of the bleeding disorder haemophilia are caused by a deficiency in the gene for a protein involved in blood clotting. Specifically, haemophilia A (also known as Factor VIII deficiency) affects men who have an abnormal copy of the gene encoding the Factor VIII blood protein. If a normal copy of this gene could be inserted into a herpes simplex virus, and then this virus used to infect cells of the liver, those infected liver cells can then produce quantities of normal Factor VIII and improve the ability of the patient's blood to clot properly. Crusade has already developed an attenuated HSV1 virus bearing the Factor VIII gene and has begun pre-clinical experiments to assess the potential of such an approach.