Enhancing antibodies in HIV infection

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• Antibody-dependent enhancement (ADE) describes how antibodies can paradoxically increase viral infection.
• Two primary forms of ADE in HIV infection are complement-mediated (C-ADE) and Fc receptor-dependent (FcR-ADE).
• Antibodies targeting specific HIV epitopes, such as gp41 for C-ADE and gp120 for FcR-ADE, are implicated.

Purpose of the Study:

• To summarize the history, mechanisms, and clinical significance of antibody-dependent enhancement (ADE) in HIV infection.
• To review hypotheses explaining ADE in vitro and discuss supporting evidence for its in vivo relevance.
• To explore the potential impact of ADE on HIV disease progression and vaccine development.

Main Methods:

• Review of existing literature on the discovery, mechanisms, and clinical significance of HIV ADE.
• Analysis of in vitro hypotheses for ADE, including increased viral adhesion and enhanced target cell stimulation.
• Examination of in vivo data from cross-sectional, longitudinal, and animal studies, including SIV infection models.

Main Results:

• C-ADE is associated with antibodies to the gp41 immunodominant region, while FcR-ADE involves antibodies to the gp120 V3 loop.
• In vitro ADE mechanisms include enhanced viral complex adhesion to immune cells and increased target cell susceptibility.
• Clinical data suggest a correlation between ADE-mediating antibodies and HIV disease progression, maternal-infant transmission, and altered outcomes in animal models.

Conclusions:

• ADE mechanisms, both C-ADE and FcR-ADE, are relevant to HIV pathogenesis and disease progression.
• ADE may play a role in enhancing HIV propagation and facilitating disease advancement in vivo.
• The development of ADE-mediating antibodies could potentially diminish the efficacy or prove harmful in HIV vaccine candidates.