Human iPSC-Derived Natural Killer Cells Engineered with Chimeric Antigen Receptors Enhance Anti-tumor Activity

Abstract

<p id="P3">Chimeric antigen receptors (CARs) significantly enhance anti-tumor activity of immune effector cells. While most studies have evaluated CAR-expression in T cells, here we evaluate different CAR constructs that improve natural killer (NK) cell-mediated killing. We identified a CAR containing the transmembrane domain of NKG2D, the 2B4 co-stimulatory domain, and the CD3ζ signaling domain to mediate strong antigen-specific NK cell signaling. NK cells derived from human iPSCs that express this CAR (NK-CAR-iPSC-NK cells) have a typical NK cell phenotype and demonstrate improved anti-tumor activity compared to T-CAR expressing iPSC-derived NK cells (T-CAR-iPSC-NK cells) and non-CAR expressing cells. Using an ovarian cancer xenograft model, NK-CAR-iPSC-NK cells significantly inhibited tumor growth and prolonged survival compared to PB-NK cells, iPSC-NK cells, or T-CAR-iPSC-NK cells. Additionally, NK-CAR-iPSC-NK cells demonstrate similar in vivo activity as T-CAR-expressing T cells, though with less toxicity. These NK-CAR-iPSC-NK cells now provide standardized, targeted “off the shelf” lymphocytes for anti-cancer immunotherapy. </p><p id="P4">Natural killer (NK) cells are a key part of the immune system’s ability to mediate anti-cancer activity. Kaufman and colleagues utilize human iPSCs to produce NK cells with novel chimeric antigen receptors that specifically target cancer cells in an antigen-specific manner to improve survival in an ovarian cancer xenograft model. </p><p id="P5"> <div class="figure-container so-text-align-c"> <img alt="" class="figure" src="/document_file/d7a0c5a8-43f4-4245-8cdf-b4eeb8d66f2c/PubMedCentral/image/nihms976001u1.jpg"/> </div> </p>