267 Defining the single-cell transcriptomes of splenic adaptive Natural Killer cells in donors with latent human cytomegalovirus infection

OBJECTIVES/GOALS: The primary objective of this study was to define the transcriptomes and transcriptional regulatory network required for the development and function of adaptive Natural Killer (NK) cells in donors with latent human cytomegalovirus (HCMV) infection. METHODS/STUDY POPULATION: Eight healthy adult human spleens were obtained from four HCMV seropositive and four HCMV seronegative donors. Spleens were provided by the Versiti Organ Donor Center of Wisconsin and were processed to a single cell suspension. CD7+ CD3E- CD14- CD19- CD20- NK cells were isolated, using the BD FACSAria sorter. Following cell sorting, single-cell RNA sequencing (scRNA-seq) was performed, and cDNA libraries were constructed and sequenced via NextSeq 550. Cell Ranger was then used to algin the cDNA reads and the Seurat R package was used to analyze the transcriptional data. Cells were filtered and clustered based on the number of uniquely expressed genes. The monocle software was used for single cell trajectory analysis and the SCENIC software was used to decipher gene regulatory networks. RESULTS/ANTICIPATED RESULTS: Eight healthy spleens from four HCMV seropositive and four HCMV seronegative donors were obtained and their NK cells were sorted and captured for scRNA-seq. Donor median age was 59 [IQR 48.5-56.5], 50% (n=4) were female and all donors were not experiencing any acute or chronic symptoms. Using scRNA-seq, we observed elevated numbers of NKG2C+ adaptive NK cells in HCMV seropositive individuals when compared to HCMV seronegative individuals. In addition, we identify a set of transcription markers and regulators that are responsible for the development and function of adaptive NKG2C+ NK cells. Finally, our trajectory analysis of adaptive NKG2C+ NK cells revealed a unique developmental pathway. DISCUSSION/SIGNIFICANCE: Here, we demonstrate that HCMV infection can induce the formation of adaptive NKG2C+ NK cells that display a unique transcriptional and developmental profile. These findings have the potential to influence the future application of adaptive NK cells in cellular immunotherapies.