25 Antibody-dependent Enhancement of Infection: A Mechanism for Indirect Virus Entry into Cells

Abstract

A review of receptor-mediated virus entry into vertebrate cells provides a provocative opportunity to consider the growing literature on an important mechanism of indirect entry of viruses into cells and a newly described phenomenon, antibody-dependent enhancement (ADE) of viral infection. To supplement this relatively brief treatment, the interested reader may wish to consult three recent reviews. The review by Halstead (1982) considers enhanced disease and/or infection in immune hosts and in vitro systems. Not all examples are mediated unequivocally by antibody. Porterfield (1986) provides a crisp summary of in vitro mechanisms in ADE, and Burke (1992) focuses his review on the burgeoning literature on in vitro ADE by the human immunodeficiency virus type 1 (HIV-1) and related retroviruses. The AIDS epidemic has brought a new urgency to studying direct and indirect mechanisms of viral infections—all the more urgent because antibodies, the most effective weapon available to prevent viral diseases, are peculiarly ineffective in containing HIV infection.

The consummate biologic importance of antibody-enhanced (or other ligand-enhanced) cellular infection by viruses or other intracellular organisms resides in the contributions of this mechanism to enhanced clinical disease in human beings or other vertebrates and to the survival and evolution of intracellular microorganisms. Since the earlier general reviews, in vitro ADE has been described in a number of new viral groups (hantaviruses [hemorrhagic fever with renal syndrome], Yao et al. 1992; nonproductive influenza A infection, Tamura et al. 1991; productive infection, Ochiai et al. 1988, 1990, 1992; nonproductive infection for the lentivirus, caprine...