# Surfactant protein-A regions as TLR4-immunomodulators

> **NIH NIH R01** · UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR · 2021 · $362,500

## Abstract

Project Summary
Lung infections and inflammation are major causes of morbidity and mortality worldwide. Uncontrolled lung
infection and its associated inflammatory injuries lead to acute respiratory distress syndrome (ARDS), for
which no specific treatment is available. An ideal therapeutic would be one that can control pathogen burden
and suppress the inflammatory response. Using computational, immunochemical, and functional screening
approaches, a Toll-like receptor (TLR4)-interacting surfactant protein-A derived peptide called SPA4 (amino
acids: GDFRYSDGTPVNYTNWYRGE) has been identified. The SPA4 peptide binds to the TLR4, suppresses
the TLR4-induced inflammation, and yet maintains the TLR4-induced pathogen-recognition, uptake and
intracellular processing. The project hypothesis is that the SPA4 peptide will reduce the pathogen burden
and inflammatory response during lung infection and inflammation by interacting with and altering the
assembly of the TLR4 complex. The specific aims are to: (1) define the molecular basis of the pro-phagocytic
and anti-inflammatory effects of the SPA4 peptide, (2) evaluate the biological effects of SPA4 peptide in mouse
models of lung infection and inflammation, and (3) analyze the activity of SPA4 peptide on TLR4-signaling and
immune function. We will determine the amino acids and motif of SPA4 peptide that are critical for binding to
TLR4 and activity against infectious stimuli. We will investigate the TLR4-assembly with its adaptor molecules
in human cells and models using structural biology, computational, molecular, biochemical, and cellular
approaches. The bacterial uptake and clearance and inflammatory parameters will be simultaneously
assessed in primary human cells. Mouse models of Pseudomonas aeruginosa- and lipopolysaccharide-
induced lung infection and inflammation will be used to test the biological relevance of SPA4 peptide. We will
investigate the SPA4 peptide’s toxicity and immunogenicity, and efficacy of SPA4 peptide upon repeat
administration, in immunosuppressed mice, in secondary challenge model, and when administered in
combination with conventional antibiotic, surfactant, or anti-inflammatory agent. Bacterial burden, inflammatory
parameters, tissue pathology, lung function, symptoms and survival will be assessed. The binding, distribution,
pharmacokinetics, and activity of SPA4 peptide will be evaluated for modulation of TLR4-dependent
mechanisms at cellular and tissue levels in lungs of wild type and genetic mouse models of TLR4 and its
adaptors, using in vivo imaging, immunohistochemistry, flow cytometry, and confocal microscopy. It is
expected that the end-point determinants of the proposed studies and analyses will eventually help establish
the mechanism of action of the SPA4 peptide. This project uses the unique concept of developing a novel
peptide-based immunotherapeutic. We anticipate that the results of this study will facilitate the development of
SPA4 peptide as an immunotherapeu...

## Key facts

- **NIH application ID:** 10225428
- **Project number:** 5R01HL136325-05
- **Recipient organization:** UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
- **Principal Investigator:** SHANJANA AWASTHI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $362,500
- **Award type:** 5
- **Project period:** 2017-08-08 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10225428

## Citation

> US National Institutes of Health, RePORTER application 10225428, Surfactant protein-A regions as TLR4-immunomodulators (5R01HL136325-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10225428. Licensed CC0.

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