Abstract Primary human myeloid cells are promising candidates for immunotherapy, yet efficient and scalable technologies for genetic engineering and screening in these cells are limited. Here we present a virus-like particle (VLP)-based toolkit that delivers diverse CRISPR genome editing modalities to human monocytes, macrophages, and dendritic cells with high efficiency while preserving viability and innate immune responsiveness. VLP-mediated delivery of ribonucleoprotein payloads supports gene knockout, base editing and epigenetic silencing, and enables site-specific integration of large DNA sequences when combined with AAV donors for homology-directed repair. Leveraging sgRNA delivery via VPX-lentivirus combined with Cas9 protein delivery via engineered virus-like particle (eVLP) treatment (SLICeVLP), we performed the first pooled loss-of-function screens in human macrophages. We uncovered regulators of TNF production and CD80 expression in human macrophages, converging on TNFAIP3 as a central regulator of inflammatory polarization. TNFAIP3 ablation promoted a pro-inflammatory cell state that is resistant to suppressive polarization, and augmented cytotoxicity of engineered HER2 CAR-macrophages. Taken together, this technology platform enables unbiased discovery and characterization of functional gene targets in primary human myeloid cells. Citation Format: Hyuncheol Jung, Pascal Devant, Carter Ching, Minetoa Ota, Jennifer Hamilton, Zachary Steinhart, Wayne Ngo, Luis Sandoval, Jae Hyung Jung, Da Xu, Merui An, Esha Urs, Peixin Amy Chen, Vincent Allain, Takuya Tada, James Nuñez, Nathaniel Landau, David Liu, Justin Eyquem, Jennifer Doudna, Alexander Marson, Julia Carnevale. Virus like particles enable targeted gene engineering and pooled CRISPR screening in primary human myeloid cells abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1580.
Jung et al. (Fri,) studied this question.