Antibody studies point the way to an HIV cure
21 days ago
- AIDS 2026 in Rio de Janeiro showed few new HIV vaccine or cure breakthroughs but presented two more stem-cell transplant cures and studies on less drastic, more accessible cure strategies.
- Broadly neutralising antibodies (bnAbs) enabled a significant proportion of participants in several studies to achieve prolonged ART-free remission, with higher rates than previously seen.
- Studies using bnAbs found no link between the size of the HIV reservoir and the likelihood of remission, overturning previous assumptions.
- Pre-existing autologous (self-generated) antibodies and stemlike CD8+ T cells are key to achieving post-treatment control.
- HIV-specific CD8 T cells in post-treatment controllers exhibited a stemlike memory phenotype with high TCF-1 expression, allowing them to respond to new or changed viruses.
- Post-treatment controllers developed a broad range of immune responses to numerous HIV strains, unlike elite controllers who had a narrow but effective response.
- In the RIO and MCA-1031 studies, more than half of participants remained off ART for prolonged periods, with viral 'blips' showing new HIV clones emerging and being suppressed by antibodies.
- The immune system in post-treatment controllers evolves over time, generating new autologous antibodies more effective than baseline ones.
- Nussenzweig concluded that future cure strategies should focus on increasing stemlike CD8+ T cells and autologous antibodies via therapeutic vaccination, and predicting responders using sequence-based methods.
- The studies have turned upside down several assumptions about HIV cure, including the roles of reservoir size, non-neutralising antibodies, and CD8 cell exhaustion.