# Structure-based Bioengineering of Wnt Surrogates for Intestinal Stem Cell Biology and Therapy

> **NIH NIH R01** · STANFORD UNIVERSITY · 2020 · $553,964

## Abstract

ABSTRACT
The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
has threatened global health. The severity of disease and rising number of deaths from SARS-CoV-2
have raised an urgent need for effective therapies. Besides respiratory symptoms, 20-50% of patients
exhibit gastrointestinal symptoms such as diarrhea and emesis. In addition, clinical evidence shows
that viral RNA can be found in rectal swabs, indicating that the intestine may be a critical target of
SARS-CoV-2 infection. In this proposal, we engineer novel high-affinity blocking agents for known entry
receptors of SARS-CoV-2 to prevent infection of human intestinal cells and pursue a longer-term goal
of structure-based discovery of novel receptor targets.
 Aim 1 designs blocking agents that target the known interaction of SARS-CoV-2 S protein with
its primary entry receptor ACE2 (angiotensin-converting enzyme 2), as well as with a novel co-receptor,
CD147 (accessory protein for monocarboxylate transporters), both of which are expressed in human
small intestinal and colon epithelial cells. In Aim 1 we will engineer an ACE2/CD147 bi-specific agent
that can simultaneously target both SARS-CoV-2 S protein receptors to improve the efficiency and
specificity of viral blockade. We utilize in vitro protein evolution by yeast cell surface display to generate
high-affinity ACE2 and CD147 ECDs with improved affinity for SARS-CoV-2 S protein versus the wild-
type ECDs These will be combined into a single bispecific agent containing both ACE2 and CD147
affinity-matured ECDs and assayed in human intestinal organoids. In particular, we deploy intestinal
organoids with a “flipped polarity” where the apical ACE2-expressing aspect faces outwards towards
the surrounding ECM/media instead of towards the interior lumen to better model physiologic viral
infection. In Aim 2, we will screen a CRISPRa activating library for additional human SARS-CoV-2
secretome targets. The SARS-CoV-2 secretome, i.e. virus-encoded secreted or surface-exposed
transmembrane proteins, also facilitates infection of host cells and provides novel targets for SARS-
CoV-2 therapeutics. This proposal leverages expertise of Chris Garcia (Multi-PI of the parental R01)
in protein engineering, immunotherapeutics, and structural biology with Calvin Kuo (Multi-PI of the
parental R01) expertise in organoid generation and disease modelling to design targeted therapeutics
for SARS-CoV-2. We also utilize collaboration from the Manuel Amieva and Catherine Blish groups in
organoid apical-basal polarity inversion and BSL3 SARS-CoV-2 infection, respectively.

## Key facts

- **NIH application ID:** 10176894
- **Project number:** 3R01DK115728-03S1
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Kenan Christopher GARCIA
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $553,964
- **Award type:** 3
- **Project period:** 2018-08-15 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10176894

## Citation

> US National Institutes of Health, RePORTER application 10176894, Structure-based Bioengineering of Wnt Surrogates for Intestinal Stem Cell Biology and Therapy (3R01DK115728-03S1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10176894. Licensed CC0.

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