Spectral flow cytometry identifies new immune signatures that provide personalized ALS risk and progression biomarkers and therapeutic targets

University Of Michigan At Ann Arbor, Ann Arbor MI

Investigators

Abstract

ABSTRACT Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease with no cure, and although inflammation plays a significant role in the disease, gaps remain in leveraging this knowledge for personalized clinical outcome models and personalized therapeutics. Peripheral blood immune profiles—defined as the total numbers and activation states of specific peripheral immune cells—reflect overall inflammation, but methodologic gaps exist to characterize these immune profiles given limitations in conventional flow cytometry, hampering its widespread use for ALS. The long-term goal is to leverage immune profiles to identify dysregulated immune pathways that can be treated to slow or stop ALS progression. The overall objective in this proposal, being submitted in response to RFA-TS-25-036 Funding Option A, is to establish spectral flow cytometry as the state-of-the-art approach to characterize peripheral immune profiles in ALS. The central hypothesis is that spectral flow cytometry will yield rigor and reproducibility with fresh and frozen blood samples and will identify pro-inflammatory immune profiles for ALS clinical outcome prediction. The rationale is that establishing rigorous protocols for the widespread multicenter use of spectral flow cytometry in ALS will unlock the complex, but vast, potential of the immune system for improving diagnosis, prognosis, and drug development for all persons with ALS. The central hypothesis will be tested by pursuing two specific aims: 1) Utilize spectral flow cytometry to quantify inflammation in ALS peripheral blood biosamples and determine the consistency of immune markers between samples processed fresh versus frozen to inform multisite ALS studies; and 2) Determine the natural history, diagnostic, and prognostic significance of comprehensive longitudinal spectral flow cytometry immune profiles as an ALS inflammatory signature. Under the first Aim, spectral flow cytometry protocols will be optimized to characterize ALS inflammation in fresh and frozen samples, paving the way for its use in multisite ALS studies. Under the second Aim, immune profiles will be associated with important ALS clinical outcomes, such as case status and disease progression. The research proposed in this application is innovative, in the applicant’s opinion, because it moves the field in a new direction—bridging both mechanistic and knowledge gaps—by bringing the transformational potential of spectral flow cytometry to ALS, establishing the rigor needed to make the technology widely available to the ALS community, leveraging the resulting data to better understand the role of comprehensive immune profiles for ALS, and providing the foundation for future multisite studies. The proposed research is significant because peripheral blood immunophenotyping will enable improved ALS clinical outcome associations, and eventually therapeutic target identification, testing, and responder analysis.