# The Function of Small Proline Rich Proteins in Cutaneous Host Defense

> **NIH NIH K08** · UT SOUTHWESTERN MEDICAL CENTER · 2020 · $159,634

## Abstract

Project Summary/Abstract: Skin and soft tissue infections are a major public health threat.
Exacerbating the problem has been the development of antibiotic resistant strains of bacteria. Like
the hide of an animal, human skin creates a physical barrier between a person and its environment. The
skin is also home to cells and molecules of the immune system that create an immunological barricade to
infection. A critical component of the skin barrier are antimicrobial proteins- evolutionarily ancient immune
effectors that maintain mutually-beneficial host-microbial relationships at multiple epithelial surfaces, such
as the skin and the intestine. Recently, we discovered that proteins in the Resistin family (human Resistin
and mouse RELMα) are antimicrobial and expressed by keratinocytes and by sebaceous glands - the oil
producing glands of the skin. In addition to RELMα, there are innumerable proteins elaborated by
sebaceous glands with unknown biochemical function. Little is understood about the role that bacteria play
in regulating the expression of these proteins. We thus wanted to identify other genes expressed by the
sebaceous gland that might, 1) play a role in host defense and 2) modulate the skin microbiome. Using
whole transcriptome sequencing (RNA-seq), we compared the expression profile of sebocytes treated with
lipopolysaccharide (LPS) to sebocytes treated with a vehicle control. We were surprised to find that 4
members of the small proline rich family (gene name SPRR) were upregulated by LPS. SPRR proteins
also have structural features similar to other described antimicrobial proteins. Our preliminary data indicate
that SPRR1A and SPRR2A proteins can kill skin commensals in vitro. In this proposal we will utilize an
array of in vitro and in vivo techniques to: (Aim 1) determine whether SPRR1A can kill bacterial pathogens,
(Aim 2) delineate how SPRR1 proteins are secreted from skin, and (Aim 3) determine the physiologic
function of SPRR2A in skin. These studies will help us understand how the sebaceous gland contributes
to cutaneous host defense.
 My long-term career goal is to develop an independent research program that investigates host
defense at the skin surface. After completing MD/PhD and Dermatology training at Johns Hopkins, I was
recruited to UT Southwestern to train as a post-doctoral fellow in the lab of Lora Hooper, Ph.D, an
internationally recognized leader in mechanistic studies of the host/microbe interface and the
characterization of antimicrobial proteins in the gastrointestinal tract. During my tenure in the Hooper lab,
I have expanded the focus of the lab to include skin. This career develop award will support my final years
in this unique training environment and give me the opportunity to gain new skills in: 1) cellular trafficking
biochemistry and 2) bacterial genomics. I have created a mentorship team of scientists to help fill these
gaps in my training, Sandra Schmid Ph.D., Heidi Kong M.D., and Julia Segre Ph.D. T...

## Key facts

- **NIH application ID:** 9871745
- **Project number:** 1K08AR076459-01
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** Tamia Alisha Harris-Tryon
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $159,634
- **Award type:** 1
- **Project period:** 2020-04-10 → 2025-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9871745

## Citation

> US National Institutes of Health, RePORTER application 9871745, The Function of Small Proline Rich Proteins in Cutaneous Host Defense (1K08AR076459-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9871745. Licensed CC0.

---

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