The McFadden lab studies the nature of how viruses interact with the host immune system, in particular the mechanisms that determine the host tropism of poxviruses. The lab is also developing specific poxviruses as novel virotherapy candidates for the oncolytic treatment of human cancers. The lab has investigated the molecular basis for the host and cellular tropism specificity of poxviruses, using the myxoma virus model system as a novel platform for replication-restricted vaccine vectors and as an oncolytic virus. His lab also studies how viruses in general can occasionally leap from a long-term evolutionary host species to cause zoonotic infections in humans. He is currently collaborating with U Florida researchers (Drs. Chris Cogle, Ed Scott and Gerard Madlambayan) to develop a novel strategy of using myxoma virus to selectively purge human leukemia/lymphoma cancer cells from patient bone marrow samples ex vivo, prior to engraftment, as an adjunct treatment for autologous blood and marrow transplantation (ABMT). Our lab is also investigating whether myxoma virus can selectively infect and kill primary human cancer stem cells but leave normal human stem cells untouched.