John M. Coffin

Retroviruses are important not only as causes of human disease, but also as valuable models for normal and pathogenic processes. My research involves understanding retroviral replication, disease induction, and evolution. Replication is characterized by a high level of genetic variation, including mutation, recombination, and acquisition of cellular genes (transduction), all important roles in the retrovirus' ability to evolve and cause disease. I have studied the connection of these processes to replication, discovering, for example, "jumping" of reverse transcriptase that can lead to high rates of recombination, as well as the likely mechanism of transduction of cellular genes and their conversion to cancer-causing oncogenes. Other studies found that a retrovirus insertion was responsible for a mutation causing some mice to lose their hair at an early age and that endogenous viruses help protect their host against retrovirus infection by encoding superantigens that affect the interaction of the virus with the immune system.