# Role of cannabinoid receptor 1 in lung injury and resolution

> **NIH NIH R21** · UNIVERSITY OF WASHINGTON · 2020 · $220,625

## Abstract

Abstract
The primary route for consuming marijuana, the most commonly used recreational drug, is by smoking; yet, its
effects on the lung remain largely unexplored. Two cannabinoid receptors (CBR), which bind both to
endogenous cannabinoids and to ∆9-tetrahydrocannabinol (THC – the primary active component of marijuana)
are described. Although CB1R is classically reported to be expressed in the central nervous system, recent
publications and preliminary data in this grant indicate expression in macrophages in the lung. CB2R is also
expressed on alveolar macrophages. The effect of CBR signaling in host response to infectious exposures
have primarily been limited to studying impact of endogenous cannabinoids via genetic deletion of CBRs
and/or use of pharmacologic inhibitors. Published data are inconclusive and support both beneficial and
harmful effects of CBR signaling in response to bacterial and viral infections. Furthermore, data on the effects
of exogenous cannabinoid signaling via marijuana exposure on host response to infections, including influenza
infection are lacking. This project proposes to investigate the impact of marijuana smoke exposure on the lung
using clinically relevant animal models and state-of-the-art molecular biology methods. Utilizing a smoking
chamber, we will expose normal mice and mice lacking CB1R or CBR2 to marijuana for up to 4 weeks. The
impact of marijuana smoke and CBR2 signaling on host response to influenza and macrophage phenotype will
be determined in Aim 1. Aim 2 investigates whether marijuana smoke exposure alters resolution of lung injury,
promoting fibrosis. Collectively, this project will provide new insights into the role played by marijuana use in
altering the lung’s immune state and lay the groundwork for future studies to unravel the potential
pathophysiologic consequences of chronic marijuana use. Given that studies also implicate CBR signaling in
non-infectious lung diseases such as asthma and pulmonary fibrosis, findings will have potential impact
beyond influenza infection.

## Key facts

- **NIH application ID:** 9936426
- **Project number:** 5R21AI147536-02
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** William A Altemeier
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $220,625
- **Award type:** 5
- **Project period:** 2019-06-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9936426

## Citation

> US National Institutes of Health, RePORTER application 9936426, Role of cannabinoid receptor 1 in lung injury and resolution (5R21AI147536-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9936426. Licensed CC0.

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