Highlights d Neutrophils recruited to cystic fibrosis airways undergo de novo RNA transcription d Neutrophil adaptation to CF airways leads to downregulation of their antimicrobial genes d Transcriptional blockade restores CF airway neutrophil bactericidal capacity

The majority of genetic variants affecting complex traits map to regulatory regions of genes, and typically lie in credible intervals of 100 or more SNPs. Fine mapping of the causal variant(s) at a locus depends on assays that are able to discriminate the effects of polymorphisms or mutations on gene expression. Here, we evaluated a moderate-throughput CRISPR-Cas9 mutagenesis approach, based on replicated measurement of transcript abundance in single-cell clones, by deleting candidate regulatory SNPs, affecting four genes known to be affected by large-effect expression Quantitative Trait Loci (eQTL) in leukocytes, and using Fluidigm qRT-PCR to monitor gene expression in HL60 pro-myeloid human cells. We concluded that there were multiple constraints that rendered the approach generally infeasible for fine mapping. These included the non-targetability of many regulatory SNPs, clonal variability of single-cell derivatives, and expense. Power calculations based on the measured variance attributable to major sources of experimental error indicated that typical eQTL explaining 10% of the variation in expression of a gene would usually require at least eight biological replicates of each clone. Scanning across credible intervals with this approach is not recommended.

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OBJECTIVES/GOALS: In 2020 the Georgia CTSA Clinical Research Center site at Emory University developed a highly trained, credentialed research coordinator pool with a goal to expand the pool to include clinical research coordinators from our partner institutions with the ability to work across institutional barriers in support of Georgia CTSA investigators. METHODS/STUDY POPULATION: Fall 2022, an Emory Investigator requested Georgia CTSA Biorepository samples with supporting clinical data for a NIH funded study. This provided a pilot opportunity to utilize clinical research nursing support offered by the UGA Clinical and Translational Research Unit (CTRU). De-identified samples were collected from our Biorepository while Emory’s coordinators and lab collaborated with UGA’s nursing support for data collection. Our obstacle for cross-institutional support was access to Emory Healthcare (EHC) medical records that would be needed by the UGA nurses, but partnerships created with the Georgia CTSA allowed us to overcome this, granting access to the electronic medical records (EMR) needed to complete the study. RESULTS/ANTICIPATED RESULTS: As expected, the process of credentialing and gaining access to the EHC EMR for the UGA team was the most time-consuming in the development of the pool. Discussions began in June 2021 to determine needs to allow the UGA research nurses to support the Emory coordinator pool. Requirements included acquiring an EHC network ID, completion of required Emory research training, letters of support from the Georgia CTSA outlining the collaboration between institutions, and a credentialing application. All steps were completed in May 2022 and the team began to identify studies that could benefit from this collaboration. Given that all credentialing and access needs were in place, the team was able to initiate the study and complete all study requirements, from sample identification to data collection and clean up, in five weeks. DISCUSSION/SIGNIFICANCE: Workforce shortages of experienced clinical research coordinators make it imperative to overcome barriers presented by institutional rules in order to efficiently utilize available resources to conduct high quality research. The CTSAs provide the perfect opportunity for partner institutions to develop processes to allow support across sites.

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