Comparative evaluation of synthetic cytokines for enhancing production and performance of NK92 cell-based therapies

Autologous immune cell therapies are potentially curative, but cost and manufacturing complexity limit access. Off-the-shelf therapies may address these gaps, but further development is needed. The NK92 cell line has a natural killer-like phenotype, has efficacy in cancer clinical trials, and is safe after irradiation. However, NK92 lose activity post-injection, limiting efficacy. This may be addressed by engineering NK92 to express stimulatory factors, for which comparative analysis is needed. Thus, we systematically explored expression of synthetic cytokines for enhancing NK92 production and performance. All synthetic cytokines evaluated (membrane-bound IL2 and IL15, and engineered versions of Neoleukin-2/15, IL15, IL12, and decoy resistant IL18) enhanced NK92 cytotoxicity. Genetically modified cells preferentially expanded by expressing membrane-bound but not soluble synthetic cytokines, and all engineered cells remained sensitive to irradiation. Interestingly, some membrane-bound cytokines conferred cell-contact independent paracrine activity partly attributable to extracellular vesicles. Finally, we characterized interactions within consortia of differently engineered NK92.