Activated T cells in patients with autoimmune diseases, cancer or viral infections expose large amounts of B7H6 on their surface. Co-culture experiments in the culture dish have shown that Natural Killer (NK) cells recognize activated T cells by their B7H6 expression. In contrast, T cells whose B7H6 gene was knocked out with CRISPR-Cas were protected from lethal NK cell attack. B7H6 can now be classified as another inhibitory immune checkpoint on T cells. Researchers have thus discovered that NK cells can thus alter the effect of cancer therapies using immune checkpoint inhibitors (ICIs). They may also be responsible for the rapid decline of therapeutic CAR-T cells. Interventions in this mechanism could potentially improve the efficacy of these cellular cancer immunotherapies.
