The DARC conspiracy--virus invasion tactics.

Is there a "conspiracy" at work among viral pathogens? Apparently, yes. Rabies virus, lenti- and retroviruses, and herpesviruses, the "co-conspirators", target select members of the tumor necrosis factor (TNF) receptor superfamily to invade the cells of their host. The intrigue deepens, as several reports have revealed that the viral envelope proteins interact with the cellular TNF receptor in a highly conserved region of previously unknown function. Targeting of this region by diverse pathogens suggests that a selective advantage is acquired. This advantage might involve regulation of the immune response, because recent investigations of the herpesvirus entry receptor demonstrated that this conserved region engages an inhibitory co-receptor governing T-cell activation.