BK Virus, a papovavirus which is highly prevalent in the human population, is related to and shares some antigenic and biochemical properties with the better characterized simian virus SV40. Infection with BKV leads to the production of tumor or T-antigens, which in the case of SV40, have been shown to play a central role in the oncogenicity of the virus. Whilst the ability of BKV to infect human cells, to transform a variety of cells in culture and to induce tumors in hamsters is well documented, the molecular basis of these activities remains poorly understood, more importantly it is not established whether BKV is involved directly in human neoplasia. In this contract, the contractor will generate a series of polyclonal and monoclonal antibodies specific to both the BKV large-T and small-t antigens. They propose to achieve specificity by raising antibodies to peptides corresponding to the unique carboxy-terminal portions of the proteins. By raising monoclonal antibodies, they expect to be able to select antibodies of high affinity. The contractor plans to use the antibodies to study the biochemical and biological properties of the BKV T-antigens and their possible role in human neoplasia.