# The Role of Sleep in Innate Immune Homeostasis: Toward Mechanistic Understanding Through Genome-Wide Enhancer Analysis

> **NIH VA IK2** · VA SAN DIEGO HEALTHCARE SYSTEM · 2023 · —

## Abstract

The sleep-immune axis is highly complex, and the negative impact of inadequate sleep on immune
dysfunction is well recognized. Unfortunately, sleep disorders are highly prevalent among Veterans; as a result,
understanding how sleep influences immune regulation offers novel therapeutic strategies for inflammatory
diseases associated with poor sleep. The transcription factors (TFs) and gene regulatory programs involved in
the sleep-immune axis are not fully understood. Analysis of genome-wide changes in the activity of cis-regulatory
elements, or cistrome, offers an unbiased assessment of TF activity to identify key pathways regulating the sleep-
immune axis. The studies I propose in this CDA-2 application will identify and test TF network pathways
contributing to alterations in neutrophil function during sleep disruption. Because of my clinical practice in critical
care medicine, I am focusing on understanding the mechanistic impact of sleep on sepsis.
 Using an established murine model of sleep fragmentation, I have identified phenotypes of immune
dysfunction related to sleep disruption. Previous studies showed sleep disrupted mice had worse outcomes in
pathogen-based sepsis models. Whether the mortality is a consequence of an early hyperinflammatory response
or a sequala of poor pathogen clearance is uncertain. In this proposal, I specifically tested for the impact of sleep
on the early inflammatory response to sepsis using the pathogen-free, endotoxin-induced peritonitis model. Mice
with sleep disruption had less mortality than matched controls upon LPS-induced peritonitis, suggesting a
dampened acute inflammatory response. Consistent with this notion, peritoneal neutrophils from sleep-disrupted
septic mice have lower expression of Myeloperoxidase (Mpo), a critical enzyme in reactive oxygen species (ROS)
production. Single-cell RNA sequencing from the bone marrow of sleep-disrupted mice showed global
transcriptomic changes in mature neutrophils with activity signature of Stat3, a TF that mediates
immunosuppressive response. These findings support my hypothesis that neutrophil phenotype and function are
sensitive to sleep perturbation. Using the innovative approach of cistrome analysis, I aim to identify the
mechanistic TF pathways by which sleep disruption impacts neutrophil function. The overarching goal is
to identify pathways that could be targeted to modulate neutrophil activation to treat Veterans suffering from the
adverse consequences of sleep disruption.
 This proposal addresses the impact of sleep on neutrophil function through transcriptional regulation.
First, I will investigate whether sleep disruption reduces the fundamental capabilities of neutrophils, including
ROS production, phagocytosis, and NETosis (AIM1). I will then use cistromic tools to test whether the sleep
disruption affects the transcriptional activity of Stat3 (AIM2). Using ChIP-seq, I expect a global change in Stat3
binding in cis-regulatory elements at a genome-wid...

## Key facts

- **NIH application ID:** 10589548
- **Project number:** 1IK2BX005908-01A1
- **Recipient organization:** VA SAN DIEGO HEALTHCARE SYSTEM
- **Principal Investigator:** Michael Tun Yin Lam
- **Activity code:** IK2 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2023
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2022-10-01 → 2027-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10589548

## Citation

> US National Institutes of Health, RePORTER application 10589548, The Role of Sleep in Innate Immune Homeostasis: Toward Mechanistic Understanding Through Genome-Wide Enhancer Analysis (1IK2BX005908-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10589548. Licensed CC0.

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