Subtractive Methods for Detecting New Retroviruses

The long-term goal of this proposal is to identify new retroviruses that play a causative role inhuman diseases. During Phase I, we propose to develop methods that will allow the identification andisolation of any exogenous retrovirus in a human diseased tissue sample, without requiring pre-existingknowledge of its primary genetic sequence. The proposed modifications of the representationaldifference analysis (RDA) method will enable us to isolate retroviral genes from any human tissue source,including fresh, forzen, or fixative preserved tissues and paraffin archival blocks, using either RNA orDNA as starting template. The development of these techniques will allow us to isolate and identifycontributing retroviruses that cannot be identified by any other existing method. Once established,during Phase II, these methods will then be applied to screen a large variety of human diseased tissueand blood samples for the presence of a new retrovirus that is exogenous to the human genome.