Intracellular signaling as measured by single cell network profiling (SCNP) is stable in longtitudinal samples of peripheral blood mononuclear cells (PBMC) from healthy donors (HD) across multiple immune cell subsets (TECH1P.839)

Abstract

Abstract Biomarkers of immune function from viable cells would be of high value for many clinical applications. The immune system responds rapidly to a variety of stimuli, so identifying immune measures that are stable, robust, and relevant to clinical features/outcomes can be challenging. SCNP is a multiparametric flow cytometry assay measuring induced changes in intracellular signaling, providing a functional measure of pathway capacity in multiple cell subsets without physical separation. To assess the longitudinal stability of signaling capacity, PBMCs from 11 healthy donors (7 female, age 29 - 60) were collected at 2 time points and characterized by SCNP of 32 nodes (combinations of a modulator and an intracellular signaling readout) in 21 cell subsets. Signaling stability was assessed for each node:subset combination, calculating the ratio of the signaling variability between time points to the mean signaling level. Of 258 node:subset combinations measured: 160 (62%) had a ratio <0.1; 227 (88%) were <0.2 (i.e. the variability between time points is <20% of the average signaling). Memory B cells had the greatest, though modest, variability in signaling between sample times (median ratio 0.15, range 0.04 - 0.43); naive CD4- T cells had the least variation (median ratio 0.066, range 0.03 - 0.13). This study serves as reference for biomarker development for immune monitoring, demonstrating that signaling capacity is a stable, robust phenotype over time and within an individual.