# The Role of Neutrophil Mechanosensing During Oropharyngeal Candidiasis

> **NIH NIH F31** · BROWN UNIVERSITY · 2021 · $5,806

## Abstract

Project Summary / Abstract
 Neutrophils are the first responders to sites of infection and are fundamental to the anti-fungal response.
This includes conditions of oropharyngeal candidiasis, where blood neutrophils extravasate into infected tissues
and locomote to contact invading Candida. During this process, neutrophils are highly sensitive not only to the
biochemical properties of the tissue microenvironment but the physical properties as well. The oral cavity is
highly variant in the mechanical properties of its composite tissues, from the relatively soft and elastic tongue
and soft palate to structures of relatively intermediate stiffness such as the esophagus to rigid structures such
as the hard palate. The Reichner lab and others have shown that human neutrophils are highly sensitive to the
mechanical features of their microenvironment including substrate stiffness. They have reported that human
neutrophils move more slowly and with greater directionality when placed on stiff matrices as compared to soft
matrices. Quantification and mapping of tractional forces show greater force generation on stiffer matrices with
most of the force produced at the rear of the cell. A significant gap regarding these findings is that we have no
information regarding how a pathogen, or its component PAMPs, affect the mechanosensitive response of
neutrophils with regard to overall motility and the production of traction on matrices of varying stiffnesses. This
is significant because it is the pathogen that induces neutrophil entry into an infected tissue to execute
antimicrobial activity, and Candida infection is highly relevant in the oral cavity as a cause of OPC. The
overarching hypothesis to be tested in this proposal is that the presence of candida affects the mechanosensitive
properties of the human neutrophil. In Aim 1, we will use tunable elasticity hydrogels to determine how substrate
stiffness regulates the neutrophil anti-Candida effector responses and, in turn, how the candida PAMP beta-
glucan, affects the generation of traction force.
 Additionally, tissues are highly confined 3-dimensional spaces and, as such, are different than the 2D
tissue culture substrates typically used for in vitro studies. Again, citing prior work from Reichner and colleagues,
the physical property of confinement has a significant affect on neutrophil motility and traction. For example,
whereas neutrophils are known to require integrins for adhesion and migration on 2D surfaces, integrins become
dispensable for migration following entry into the highly confined 3D interstitial space. To study the sensitivity of
neutrophils to physical confinement, we developed a double hydrogel compression device and have shown that
confinement is the physical trigger for neutrophils to switch to integrin-independent migration and generation of
traction. Therefore, although prior work has shown mechanosensitive effects on neutrophil integrin engagement
in motility, nothing is known abou...

## Key facts

- **NIH application ID:** 10160640
- **Project number:** 5F31DE028745-03
- **Recipient organization:** BROWN UNIVERSITY
- **Principal Investigator:** Hadley A. Witt
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $5,806
- **Award type:** 5
- **Project period:** 2019-07-01 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10160640

## Citation

> US National Institutes of Health, RePORTER application 10160640, The Role of Neutrophil Mechanosensing During Oropharyngeal Candidiasis (5F31DE028745-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10160640. Licensed CC0.

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