EB Simplex is caused by defects in keratin genes. Keratins are filamentous proteins which are found in a number of tissues including the skin. They are important for its structural integrity and alterations in these proteins can make the cells fragile and less resilient to mechanical stress. A great deal of progress has been made in recent years in identifying the mutations (changes in DNA) which are responsible for EB Simplex and in some cases it is now possible to carry out prenatal testing for the disorder. There is still no treatment or cure.

The murine gene encoding keratin K14, a gene responsible for EB Simplex, will be cloned and fully sequenced. The human K14 promoter will also be cloned and sequenced. A murine transformed keratinocyte cell line will be produced. Chimeric U1 riozyme constructs will be produced to inactivate K14 expression in stable murine keratinocyte clones. Subsequently, K14 expression will be replaced by a transfection of a genetically modified "ribozyme immune" version of the K14 cDNA into the latter clones. A single plasmid will be engineered which will simultaneously turn off expression of endogenous K14 and replace this with modified ribozyme immune K14 in cultured murine keratinocytes and ultimately, in the skin of transgenic mice.

This study will test the ability of chimeric ribozymes to enable switching of keratins or other genes causing the dominant forms of EB, both in cultured cells and in vivo, an important step on the way to gene therapy for EB patients.

Dr McLean is an experienced and successful EB Researcher. DebRA has funded him previously when he was part of Prof Birgitt Lane's group in Dundee. Dr McLean worked with Prof Uitto in Philadelphia and is now returning to the UK. He has been awarded a Wellcome Programme Grant of £818,000 to establish a laboratory in the UK. The Wellcome Grant does not include the purchase of a Gene Sequencer. This is included in the figures below. Dr McLean is also the holder of the DebRA Princess Diana Research Fellowship.