Lipids in the viral envelope - Anti-phospholipid chimeric antibodies

Tarvacin (now known Bavituximab) is a chimeric (human-mouse) monoclonal antibody against phosphatidyl serine. In normal cells, the outer layer of the plasma membrane contains choline phospholipids while the inner monolayer contains amino phospholipids (phosphatidyl serine and phosphatidyl ethanolamine) (figure 26). Viruses lack the ability to maintain this asymmetry and phosphatidyl serine appears on the surface of the virus membrane. Thus, this phospholipid can bind antibodies leading to opsonization and complement-mediated lysis of the virus membrane (figure 1). In animal protection experiments, Tarvacin provided significant protection against lethal viral loads of pichinde virus (a model of lassa fever) with 50% of the drug-treated animals and none of the animals receiving control treatment surviving. This drug is in phase I trials for hepatitis C patients and may be useful against HIV and many other enveloped viruses.

Figure 1
Targeting of flipped phospholipids