Basic approach to gene therapy

Viral-based vector systems Non-viral-based vector systems 

Adeno-associated virus Direct injection of naked DNA 

CH14 NUCLEIC-ACID- AND CELL-BASED THERAPEUTICS 

The in vitro approach entails initial removal of the target cells from the body. These are then cultured in vitro and incubated with vector containing the nucleic acid to be delivered. The genetically altered cells are then reintroduced into the patient s body. This approach represents the most commonly adopted protocol to date. In order to be successful, however, the target cells must be relatively easy to remove from the body, and reintroduce into the body. Such in vitro approaches have successfully been undertaken utilizing various body cell types, including blood cells, stem cells, epithelial cells, muscle cells and hepatocytes. 

A second approach involves direct injection/administration of the nucleic-acid-containing vector to the target cell, in situ in the body. Examples of this approach have included the direct injection of vectors into a tumour mass, as well as aerosol administration of vectors (e.g. containing the cystic fibrosis gene) to respiratory tract epithelial cells. 

While less complicated than the in vitro approach, direct in situ injection of vector into the immediate vicinity of target cells is not always feasible. This would be true, for example, if the 

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Basic approach to gene therapy The basic approach to gene therapy involves (Figure 1.12) ... 

The adrenal cortex plays a key role in regulating intermediary metabolism, fluid and electrolyte balance, and the response to stress. Molecular analyses of specific disorders resulting from either the diminished or enhanced produc-tion/action of corticosteroids have led to the identification of a number of genes that play key roles in adrenal function and corticosteroid action. These genes provide potential targets for novel therapies that may revolutionize our approaches to these rare adrenal diseases. In addition, understanding the molecular causes of these diseases has provided important insights into basic adrenal functions that may translate into improved therapy of more common disorders such as hypertension and obesity. 

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