# Disordered Proteostasis as a Driver of Disease in the Aging Lung

> **NIH NIH P01** · NORTHWESTERN UNIVERSITY · 2020 · $317,542

## Abstract

Pneumonia is the leading cause of death in patients with COVID-19 infection and disproportionately affects older
individuals. In addition to the diffuse patchy alveolar infiltrates and acute hypoxemic respiratory failure typical of
viral pneumonia, patients with COVID-19 often develop hypotension requiring alpha-adrengergic agonists, very
high serum levels of IL-6 and its transcriptional target C-Reactive Protein (CRP) and display evidence of
intravascular coagulation. This is accompanied by the death of cells in multiple tissues including the kidney,
muscle, liver and occasionally the heart. This end-organ injury is an important driver of morbidity and perhaps
mortality in COVID-19 patients. These unusual clinical features suggest a virus-induced cytokine storm, but the
underlying mechanisms are unknown and these clinical features are not recapitulated in rodent or primate
models of the disease.Our early analysis of bronchoalveolar lavage fluid collected from the alveolar space of
patients with severe COVID-19 pneumonia requiring mechanical ventilation challenge the existing paradigm that
IL-6 originates in immune cells within the alveolar space. Specifically, we found that at the time of intubation, the
alveolar space in the majority of patients with severe COVID-19-induced ARDS harbors mature alveolar
macrophages and lymphocytes none of which produce IL-6. Instead, a subset of resident alveolar macrophages
produce IL-1? and appear to support replication of SARS-CoV-2.We hypothesize that disordered
proteostasis in alveolar macrophages from aged individuals prevents viral killing after uptake of SARS-
CoV-2. Replicating virus activates the inflammasome to induce IL-1? release in the lung, which in turn induces
the release of IL-6 from endothelial cells in the lung and distant organs. We will test this hypothesis in two related
experiments. Experiment 1. To determine whether activation of the inflammasome in response to COVID-
19 infection is necessary for the release of IL-6 from the lung endothelium. We will infect lung slices from
normal human donors with SARS-CoV-2 in the presence or absence of an IL-1? inhibitor that is under evaluation
as a therapy for patients with COVID-19 associate pneumonia (canakinumab). We will examine the lung slices
after infection using single cell RNA-Seq and RNAscope. Experiment 2. To determine whether endothelial
cells in tissues outside the lung express IL6 in patients with severe COVID-19. We will perform RNAscope
on fixed tissues harvested from 9 patients who have undergone autopsy after COVID-19 at Northwestern and
RNAscope plus single cell RNA-Seq on lung, kidney, spleen and lymph nodes from 5 patients who undergo post-
mortem biopsy in our ICU.

## Key facts

- **NIH application ID:** 10208506
- **Project number:** 3P01AG049665-06S1
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** GR Scott Budinger
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $317,542
- **Award type:** 3
- **Project period:** 2015-07-01 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10208506

## Citation

> US National Institutes of Health, RePORTER application 10208506, Disordered Proteostasis as a Driver of Disease in the Aging Lung (3P01AG049665-06S1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10208506. Licensed CC0.

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