Biology subjects

Jarrell, J. A.

Publications and source records attributed to Jarrell, J. A..

2 recordsLinked to original sources

bioRxiv2026

Onsite fixation preserves phosphoprotein profile in human whole blood

Phospho-flow cytometry is increasingly used as a pharmacodynamic readout of kinase-pathway activity, including in JAK inhibitor trials. Phosphoprotein states are intrinsically labile ex vivo and are further altered by conventional workflows, which typically involve PBMC isolation, cryopreservation, and transit times of hours to days before measurement. Here, we fix whole blood at collection and quantify six phosphoproteins by mass cytometry, benchmarked against matched cryopreserved PBMCs. Unlike PBMCs, whole blood retained neutrophils, ~75-80% of which were pSTAT3-positive at baseline. Basal pSTAT3 was also markedly higher in whole blood monocytes (~41% positive vs. ~9% in PBMCs), whereas T, B, and NK cells differed by less than 1 percentage point. Stimulation produced subset-specific phosphorylation patterns that were retained after 6 weeks of storage. Because fixation does not require centrifugation and retains neutrophils, samples can be fixed at collection sites without on-site processing laboratories and analyzed centrally in batches.

immunology↗

bioRxiv2020

Numerical optimization of microfluidic vortex shedding for genome editing human primary T cells using machine learning

Microfluidic vortex shedding (VS) can rapidly deliver mRNA to T cells with high yield. The mechanistic underpinning of VS intracellular delivery remains undefined and VS-Cas9 genome editing requires further studies. Herein, we evaluated a series of VS devices containing splitter plates to attenuate vortex shedding and understand the contribution of computed force and frequency on efficiency and viability. We then selected a VS design to knockout the expression of the endogenous T cell receptor in primary human T cells via delivery of CRISPR-Cas9 ribonucleoprotein (RNP) with and without brief exposure to an electric field (eVS). VS alone resulted in an equivalent yield of genome-edited T cells relative to electroporation with improved cell quality. A 1.8-fold increase in editing efficiency was demonstrated with eVS with negligible impact on cell viability. Cumulatively, these results demonstrate the utility of VS and eVS for genome editing human primary T cells with Cas9 RNPs.

immunology↗