Researchers have identified specific HIV reservoir clones that can persist for life despite treatment, posing the primary obstacle to an HIV cure. These "authentic reservoir clones" (ARCs) harbor rebound-competent virus within long-lived CD4+ T cells. A small fraction of cells within these clones express viral proteins, limiting immune system detection. Conventional immune activation is insufficient to eliminate these reservoirs.
However, sustained, high-quality CD8+ cytotoxic T lymphocyte (CTL) pressure can progressively deplete these resilient ARCs, though the process is slow. Laboratory-optimized CTLs show greater effectiveness than ex vivo measurements, highlighting the challenge of boosting natural immunity to shrink the reservoir under treatment.
Regulatory T-cell-derived ARCs exhibit intrinsic resistance to CTL killing due to lower oxidative stress. This resistance can be reversed using deferoxamine, a drug that induces hypoxic stress, making reservoir cells more susceptible to attack. Targeting these intrinsic resistance pathways, such as cellular stress responses, could enhance immune-based cure strategies by sensitizing reservoir cells to killing.