OBJECTIVES/GOALS: The objective ofthis study is to use GNR technology to track immune cells infiltrating malignant brain tumors that are delivered as part of a novel immunotherapeutic strategy. We seek to implement this new platform to elucidate the underlying mechanisms of therapeutic benefit from ACT via correlation between biodistribution and efficacy. METHODS/STUDY POPULATION: Utilizing the inherent two-photon luminescent signal of GNRs, we will identify uptake and phenotype of lineage negative hematopoietic stem cells (HSCs) in vitro. HSCs will be isolated from the bone marrow of 6-week-old C57bl/6 female mice. Following isolation, HSCs will be co-cultured with varying concentrations of GNRs in DMEM w/o sodium pyruvate for 24 hours, tested for viability, and images to quantify uptake and identify phenotyping. CT contrast of our novel Iodine-capped PEGylated gold nanorods will be confirmed through microCT and biodistribution of HSCs at time points after injection will be identified via CT visualizationin vivo. RESULTS/ANTICIPATED RESULTS: We expect that increased GNR signaling 24 hours post-transplant in the tumors of glioma-bearing mice will be positively correlated with long term survival following ACT. Published data from our labs have revealed that CCR2+ lineage-negative HSCs significantly accumulate in tumor of glioma-bearing mice12. Importantly, CCR2+ lineage-negative HSCs promote differentiation to dendritic cells in the tumor, increase antitumor T cell responses mediated by cross-priming and cross-presentation, and improve efficacy of immune checkpoint inhibition12. Given that HSCs are important in mediating immunotherapy efficacy, we seek to correlate the accumulation of GNR signaling within the tumor as a marker of treatment response. DISCUSSION/SIGNIFICANCE: Adoptively transferred cells have been imaged using numerous published methods. While promising to the field of immunotherapy, these methods lack significant clinical validation. GNRs have not been used to study hematopoietic stem cells in the context of ACT and brain malignancies. Our research is poised to address this gap.