"We have uncovered a new target that could potentially lead to new antivirals. There is certainly a need because there are no specific human papillomavirus antivirals out there at this point," said Peter Howley, the Shattuck professor of pathological anatomy at HMS.
Unlike some virusessuch as influenza, HIV, and the common cold viruswhich churn out copies within the confines of a single host cell that is then destroyed, human papillomaviruses invade proliferating epithelial cells and distribute their copies among subsequent generations. To maintain their integrity, and to ensure that the viral DNA is properly partitioned between daughter cells, human papillomaviruses have adopted the strategy of tying their genetic material, via the viral protein E2, to a protein found on the host's mitotic chromosomes. But the identity of that chromosomal protein has been elusive.
Howley, Jianxin You, HMS research fellow in pathology, and their colleagues have identified the missing chromosomal link in cells infected with a bovine form of papillomavirus. By blocking the protein, BRD4, they prevented papillomavirus-infected mouse cells from becoming cancerous. Perhaps most significant, BRD4 appears to tether human papillomavirus as well.
"This suggests that if one could come up with a small molecule or chemical that could inhibit the binding of E2 to BRD4, that could be a drug lead," said Howley. He and his colleagues are currently working with members of the Harvard University Department of Chemistry to identify such sm