Research objectives and content
The CD8 molecule is absent from early thymocytes (CD4-8-), it appears on the cell surface along with CD4 in the intermediate stage of double positive (CD4+8+) and its expression is extinguished in the CD4+ and retained in the CD8+ mature T cells.
In order to identify the sequences within the CD8 gene locus which regulate this complex pattern of expression the CD8alpha and beta genes have been cloned and putative regulatory DNaseI hypersensitive regions have been identified. We propose to generate transgenic mice carrying reporter genes under the control of such regulatory sequences in order to identify their role in the CD8 subset specific expression and consequently in the differentiation of mature cytotoxic cells. In parallel selected areas from these regulatory regions will be deleted (consititutively or inducibly) from the endogenous locus using homologous recombination techniques. Such a dual approach is expected to dissect the molecular mechanisms which underlie the regulation of expression of the CD8 molecule and the commitment to the cytotoxic T cell lineage.
Training content (objective, benefit and expected impact)
The candidate will be trained in a wide range of molecular biology techniques such as cloning, sequencing, DNA and RNA hybridisation, transgenic and knock-out technology. In addition, the candidate will be trained in a variety of immunological assays such as cytotoxic and proliferation assays, fluorescence activated sorting etc. The project will generate information which is central in understanding thymocyte development and lineage commitment. The identification of sequences which selectively direct the expression of genes in the CD8 compartment of the immune system will be useful in a variety of experimental systems including gene therapy protocols.
Links with industry / industrial relevance (22)