APOE and Proteomics in Chronic Inflammation

Product:

CNS Disease Panel 120

Topic:

Inflammation

Disease Area:

Alzheimer's Disease

Sample Type:

NA

Topic/Product:

CNS Disease Panel 120

Disease Area:

Alzheimer's Disease

Sample Type:

NA

Abstract

Apolipoprotein E (APOE) is a lipid transport protein encoded by a polymorphic gene with three common isoforms (ε2, ε3, and ε4). While APOE ε4 is widely recognized as the strongest genetic risk factor for late-onset Alzheimer’s disease (AD), proteomic studies have revealed broader immunobiological consequences of APOE variation across tissues and diseases. This chapter examines how current proteomic technologies, including mass spectrometry, SomaScan, Olink, and NULISA, are used to investigate the inflammatory functions of APOE, with an emphasis on platform-specific capabilities, limitations, and cross-platform comparability.

Proteomic studies across plasma, cerebrospinal fluid (CSF), brain tissue, induced pluripotent stem cell (iPSC)-derived models, and liver reveal consistent differences in immune signaling associated with APOE genotype. APOE ε4 is linked to widespread upregulation of inflammatory pathways, including cytokine signaling, interferon responses, complement activation, and MHC class I-mediated antigen presentation. These changes are detectable even in cognitively unimpaired individuals lacking classical AD biomarkers, indicating that APOE ε4 modifies baseline immune signaling prior to overt pathology. In iPSC-derived models, APOE ε4 intrinsically activates glial and neuronal inflammatory pathways, including STAT3 and TGF-β signaling, independent of amyloid-β or tau accumulation. Similar inflammatory signatures are observed in peripheral tissues such as the liver, highlighting the systemic nature of APOE ε4’s immunomodulatory effects. In contrast, APOE ε2 is associated with increased expression of neutrophil granule proteins and antimicrobial peptides, suggesting an immune profile skewed toward enhanced innate defense. These findings underscore the pleiotropic role of APOE in shaping both central and peripheral immune environments.

Taken together, these findings position APOE as a key modulator of immune network topology, acting through tissue-specific and cell-autonomous mechanisms. Current limitations, such as single-platform reliance and underrepresentation of non-AD phenotypes, highlight the need for multi-platform validation, longitudinal sampling, and integrative multi-omics approaches. A broader investigation of APOE’s immunoregulatory functions will be critical for identifying novel biomarkers and informing genotype-specific therapeutic strategies across neurodegenerative and systemic inflammatory disorders.

Authors & Affiliations

Artur Shvetcov¹² and Caitlin A. Finney¹²

¹ Neurodegeneration and Disease Modelling Lab, Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW, Australia
² School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia

Steve Williams, MD, PhD

CSO

Dr. Willams serves as the company’s Chief Scientific Officer. He was previously Chief Medical Officer at Standard Biotools and at SomaLogic where he pioneered the discipline for discovery and validation of predictive, diagnostic and prognostic models using machine-learning applied to large-plex proteomics. 20 such tests were used for drug characterization, safety and efficacy when incorporated in clinical drug trials at Pharma/Biotech and 17 different multivariate tests were validated and translated into regulated healthcare uses. Prior to SomaLogic, Dr. Williams was at Pfizer in the UK and the USA as a clinical triallist in Translational Medicine, and subsequently as VP, Global Clinical Technology. He sat on the National Advisory Council for the National Institute of Biomedical Imaging and Bioengineering, the Executive Committee for the FNIH Biomarkers Consortium, and worked with FDA and PhRMA on developing evidentiary standards for biomarker qualification. Dr. William’s medical training was in London, at Charing Cross and Westminster Medical School, followed by a PhD in medicine/physiology at the same institution and training in Radiology at the University of Newcastle Upon Tyne. Steve is co-inventor on 26 proteomics patents and author/coauthor on multiple foundational proteomics manuscripts.

Justin McAnear

CFO

Mr. McAnear serves as the company’s Chief Financial Officer. He brings over 25 years of operational and financial leadership experience across various sectors and was instrumental in taking 10x Genomics public in 2019, serving as its CFO for over five years. Mr. McAnear served for over 3 years as Tesla’s VP of Worldwide Finance and Operations, supporting landmark initiatives such as the Model X and Model 3 launches and Solar City acquisition. He also held various roles at Apple and J&J earlier in his career and served as a naval officer and aviator for over 9 years.