Abstract 1524: Peripheral blood mononuclear cells engineered via microfluidic Cell Squeeze® technology to generate APCs that drive mutant-KRas-specific CD8+ T cell responses

Abstract KRAS mutations are shared across multiple cancer types and are most commonly found in cancers of the lung, pancreas, and colon. While recently developed drugs blocking signaling driven by KRAS G12C mutations have shown promise in the clinic, there is a great need for therapies targeting the more common G12V and G12D mutations. We utilize our microfluidic Cell Squeeze® technology to deliver antigens directly into the cytosol of peripheral blood mononuclear cells (PBMCs) for the generation of cancer antigen-targeted cellular vaccines. This method bypasses the need for cross-presentation and directly enables efficient antigen presentation on MHC-I in multiple cell types. Murine and human in vitro studies have demonstrated that this allows SQZ PBMCs to drive CD8+ T cell activation. Here, we demonstrate the delivery of various antigens, including KRas-derived peptides containing the most common mutations (G12D and G12V) to PBMC cell subsets. In addition, we find that human PBMCs squeezed with either KRasG12V or KRasG12D peptides can specifically stimulate KRasG12V- and KRasG12D- reactive CD8+ T cell responders. When KRasG12V and KRasG12D peptides are co-delivered via microfluidic squeezing, the human PBMCs enable activation of CD8+ T cells of both specificities. This work with KRasmutant-presenting human PBMCs lays a strong foundation for developing a potentially potent cell therapy to treat KRASmutant associated cancers. Citation Format: Defne Yarar, Carolyne Smith, Amritha Ramakrishnan, Scott Loughhead, Armon Sharei, Katherine Seidl, Howard Bernstein. Peripheral blood mononuclear cells engineered via microfluidic Cell Squeeze® technology to generate APCs that drive mutant-KRas-specific CD8+ T cell responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1524.