# Regulatory Cell Therapy for Sjogrens Syndrome

> **NIH NIH R56** · UNIVERSITY OF FLORIDA · 2023 · $85,026

## Abstract

ABSTRACT
 A broad-based immunotherapeutic with the capacity to stimulate regulatory cells is needed to resolve
Sjögren's syndrome (SjS). SjS impacts several million people annually in the US with women being nine times
more likely to be affected than men. To date, no vaccines or therapeutics exist to cure SjS, and patients are
dependent on lifelong therapies focused on treating only their symptoms. Our previous work has shown that when
colonization factor antigen I (CFA/I) fimbriae from enterotoxigenic E. coli are applied either nasally or orally,
resolution of autoimmune diseases is observed. To enable testing in humans, a probiotic approach is exploited,
whereby the cfaI operon was optimized for expression by Lactococcus lactis (LL-CFA/I). In the previous funding
cycle, we demonstrated LL-CFA/I's ability to restore salivary flow in a genetically defined model for SjS,
C57BL/6.NOD-Aec1Aec2 mice. Current work seeks to improve LL-CFA/I's activity and stability by generating a
LL construct bearing the optimized cfaI operon inserted into the LL chromosome, referred to as, LL 301. To better
understand the mode of action of LL-CFA/I, the tip protein from CFA/I fimbriae, CfaE, was episomally expressed
by LL, and found to exhibit potent immune regulation of experimental rheumatoid arthritis. These fimbrial proteins
are presumed to act by inducing infectious tolerance, resulting in the stimulation of antigen-specific regulatory T
cells (Tregs) and regulatory B cells (Bregs) producing IL-10 and TGF-b. Such bystander immunity does not
render global immunosuppression, and thus, the adaptive immune response capacity remains intact. When tested
in a spontaneous, genetically defined murine model for SjS, both LL 301 and LL-CfaE showed remarkable
retention in salivary flow compared to treatment with wild-type LL or LL vector. Based upon these findings, the
proposed studies will test the hypothesis that CFA/I fimbriae and CfaE elicit bystander immunity, which in turn
regulates pathogenic CD4+ and CD8+ T cells via Tregs and Bregs producing IL-10 and TGF-b. To test this
hypothesis, three Specific Aims are proposed. Studies in Specific Aim 1 will determine the efficacy of LL 301 and
LL-CfaE via Tregs during treatment of early and late stage SjS, and identify the molecular mechanisms
responsible for salivary flow preservation. Studies in Specific Aim 2 will determine the distribution and degree of
protection conferred by Bregs induced by LL 301 and LL-CfaE. Studies in Specific Aim 3 will determine whether
protection elicited by LL 301 and LL-CfaE are FcgRIIb-dependent since CFA/I fimbriae were found to bind to the
immunoregulatory FcgRIIb. These studies will provide the basis for future testing in SjS patients, and in the
development of novel FcgRIIb agonists for treating SjS.

## Key facts

- **NIH application ID:** 10898203
- **Project number:** 2R56DE026450-06A1
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** David W Pascual
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $85,026
- **Award type:** 2
- **Project period:** 2017-04-01 → 2024-03-27

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10898203

## Citation

> US National Institutes of Health, RePORTER application 10898203, Regulatory Cell Therapy for Sjogrens Syndrome (2R56DE026450-06A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10898203. Licensed CC0.

---

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