Human adenoviruses have multiple strategies to overcome host antiviral defenses.
Apoptosis is induced by the adenovirus E1A protein, a functional homolog of Bcl-2, the well known cellular protein that inhibits apoptosis. E1B-19K keeps the cell alive so that adenovirus replication can occur. ADP is the first viral protein described to have a specific cell death-promoting function that results in the release of virus from infected cells. Accordingly, ADP represents a new concept in viral pathogenesis, i.e. rapid cell lysis will limit killing of virus by cell-mediated immunity, and therefore viral spread will be enhanced. The mechansim of action of ADP is unknown, but we have evidence that ADP may directly or indirectly interact with the E1B-19K protein and abrogate its ability to inhibit cell death.