# Pathogenic and protective roles of strain-specific P. acnes hyaluronidases in acne

> **NIH NIH R01** · CEDARS-SINAI MEDICAL CENTER · 2022 · $491,254

## Abstract

Abstract
Acne is an important skin disorder believed to be caused by skin commensal P. acnes, although how P. acnes
contributes to acne is unclear. We have identified two types of hyaluronidase enzymes, made by different
strains of P. acnes, that are either pro- or anti-inflammatory. Importantly, skin colonization by P. acnes strains
that encode the pro-inflammatory hyaluronidase is associated with development of acne, whereas colonization
with P. acnes strains that express the anti-inflammatory hyaluronidase is associated with healthy skin. In
preliminary experiments, we have shown that the pro- or anti-inflammatory property of the hyaluronidases is
related to the size of hyaluronan fragments generated by the enzymes. Therefore, we hypothesize that
hyaluronidases influence the acne-genic potential of P. acnes by degrading hyaluronan to different sizes. To
address our hypothesis, 1) we propose to investigate the structural basis of hyaluronan degradation by P.
acnes hyaluronidases, binding of hyaluronan fragments to TLR2/4 and host immune responses to the
hyaluronan fragments. 2) We propose to determine the contribution of both hyaluronidases to acne by testing
well characterized clinical strains of P. acnes and mutant strains of P. acnes that do not express hyaluronidase,
in a new mouse acne model. 3) We will also investigate hyaluronidase-based strategies for preventing or
treating acne.

## Key facts

- **NIH application ID:** 10440422
- **Project number:** 5R01AI141401-04
- **Recipient organization:** CEDARS-SINAI MEDICAL CENTER
- **Principal Investigator:** George Y Liu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $491,254
- **Award type:** 5
- **Project period:** 2019-07-18 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10440422

## Citation

> US National Institutes of Health, RePORTER application 10440422, Pathogenic and protective roles of strain-specific P. acnes hyaluronidases in acne (5R01AI141401-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10440422. Licensed CC0.

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