The long term objective of this project is to understand the molecular basis of T cell recognition of tumor antigens of lung carcinoma.
The specific aims of the proposed study are 1). to characterize the genes encoding T cell antigen receptors (TCAR) from the tumor infiltrating lymphocytes; 2). to investigate whether there is a limited expression of T cell clonotypes directed against tumor cells at the site of lung tumors. A T cell clonotype is defined by TCAR, which is composed of an alpha and a beta polypeptide chain. Each alpha and beta chain consist of Variable (V) and Diversity (D), Joining (J) and Constant (C) domains. Estimated total numbers of V beta genes of the TCAR in the murine system are around twenty. Phase I efforts will include A). an analysis of the total V beta gene repertoire available in humans and B). an analysis of those V beta genes expressed in the tumor derived T cells. For these studies a CDNA library will be prepared from tumor derived T cells using a 5' beta constant region sequence as a primer and appropriate phages as vector. Comparative analysis of these tumor derived V beta DNA sequences with the complete repertoire of V beta sequences obtained from a large peripheral T cell library will be done. These DNA sequence analyses may be extended to the V alpha genes as well as D and J regions of alpha and beta genes. The molecular analysis of the tumor derived T cells may provide a rational basis for developing the T cell receptor oriented DNA probes and monoclonal antibodies for diagnosing and monitoring lung cancer patients.
