Describe the problems that arise due to cystic fibrosis. Describe why cystic fibrosis occurs, with reference to its deficient gene. Describe the use of liposomes and viruses in treating cystic fibrosis

Describe the problems that arise due to cystic fibrosis • Produce thick, sticky mucus from epithelial cells lining certain passageways in body • Pancreatic duct becomes blocked preventing enzymes reaching duodenum • Bronchioles and alveoli of lungs become clogged, causing congestion and difficulty breathing. Mucus difficult to remove - recurrent infections Describe why cystic fibrosis occurs, with reference to its deficient gene • Cystic fibrosis trans-membrane regulator (CFTR) transports Cl- ions out of cels into mucus • Sodium ions flow out of cells, and water passes out by osmosis • So mucus is of a watery consistency • Mutation means protein is one aa different thus cannot perform function Describe the use of liposomes in treating cystic fibrosis • Gene therapy • Genes inserted into liposomes - can pass through lung epithelial cells • Aerosol inhaler delivers the liposomes • Liposome and cell surface membrane fuse, DNA released inside cell • Gene expressed Describe the use of viruses in treating cystic fibrosis • Virus rendered harmless • Virus cultured in epithelial cells along with plasmids with normal CFTR gene • Gene incorporated in viral DNA • Virus isolated and introduced to patient by inhaler • Virus injects DNA which includes normal CFTR gene into epithelial cells of lung