Figure 8-1.5: Gene Therapy using autologous cells: Cells are used, i.e. cells are removed from the patient, cultured in vitro, before being returned to the patient's body. In this figure in vivo and ex vivo gene therapy is diagrammatically explained.

(Source: http://www.ncbi.nlm.nih.gov/books/NBK7569/figure/A2897/?report=objectonly )

8-1.5.1 Ex vivo gene therapy

• In this mode of gene therapy genes are transferred to the cells grown in culture, transformed cells are selected, multiplied and then introduced into the patient.
  
  
• The use of autologous cells avoids immune system rejection of the introduced cells.
  
  
• The cells are sourced initially from the patient to be treated and grown in culture before being reintroduced into the same individual.
  
  
• This approach can be applied to the tissues like hematopoietic cells and skin cells which can be removed from the body, genetically corrected outside the body and reintroduced into the patient body where they become engrafted and survive for a long period of time.
  
  
• Figure 8-1.5.1 shows a self explanatory schematic diagram for ex vivo gene transfer.