# Contribution of Small Airways to Mucociliary Transport Dysfunction

> **NIH HL R01** · UNIVERSITY OF IOWA · 2026 · $719,078

## Abstract

PROJECT SUMMARY
The airway system is composed of asymmetric dichotomously branching tubes lined with respiratory epithelium
that form a barrier at the interface with the environment. The airways carry a simple function of conducting
oxygen rich air to the alveolar space where gas exchange with the blood occur. By doing that, pathogens and
particles enter the lungs. Mucociliary transport is a host defense mechanism that protect the lungs from
invading organisms. Defects in mucociliary transport contributes to many airway diseases such as asthma,
chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis, and primary ciliary
dyskinesia. We developed limited understanding of the mechanism of MCT in large airways by investigating
the role of submucosal gland secretions. We found that mucus strands secreted by submucosal glands are
critical to initiate movement of large particles in large airways. We also found that in CF airways, due to loss of
CFTR-mediated anion secretion, mucus strands are abnormally elastic. They fail to detach from submucosal
gland duct opening and often recoil backward while transporting on the airway surface. Small airways
constitute the majority of the surface airway of the lungs and it is suggested that may contribute to some of the
abnormalities seen in several airway diseases. The hypothesis that mucociliary defects in small airways
contribute to CF airway disease pathogenesis has largely remained untested. In addition, the characteristic
features of MCT in small airways has remained poorly understood. To understand mucociliary transport in the
small airways, we developed a positron emission based mucociliary transport assay with high spatial and
temporal resolution not achieved before. We used CF airway disease as a disease model of impaired
mucociliary transport. To realize our overarching goal of understanding the mechanism of mucociliary
transport in both small and large airways, we will test hypotheses in the f

## Key facts

- **NIH application ID:** 11289480
- **Project number:** 5R01HL167025-04
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** Mahmoud  Abou Alaiwa
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** HL
- **Fiscal year:** 2026
- **Award amount:** $719,078
- **Award type:** 5
- **Project period:** 2023-04-01T00:00:00 → 2028-02-29T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11289480

## Citation

> US National Institutes of Health, RePORTER application 11289480, Contribution of Small Airways to Mucociliary Transport Dysfunction (5R01HL167025-04). Retrieved via AI Analytics 2026-06-24 from https://api.ai-analytics.org/grant/nih/11289480. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*