# Local regulation and deletion of T cells to induce tolerance and establish long-term survival of high-risk corneal transplants

> **NIH NIH R01** · UNIVERSITY OF MIAMI SCHOOL OF MEDICINE · 2021 · $397,443

## Abstract

Immunological rejection is the most common cause of corneal allo-transplant failure particularly when the
recipient has a high risk vascularized (HRV) corneal bed. In fact, of the 40,000 patients per year receiving a
CT for vision rehabilitation, 4-6,000 are considered HRV and the success rate is dismal (<30%). Induction of
immune tolerance for these transplants is a critical and unmet medical need according to the NEI.
(https://nei.nih.gov/news/scienceadvances/advances/corneal_transplantation). The studies proposed in this
application will develop a unique combinatorial strategy never tested in a solid organ transplant to induce long-
term tolerance in recipients of high-risk vascularized corneal transplants (HRVCT) through sequential: a)
cyclophosphamide (Cy) deletion of antigen (Ag) specific effector T cells (Aim 1), b) immune suppression via
marked in vivo Treg expansion (Aim 2) and c) inflammatory gene epigenetic regulation via bromodomain
inhibitors BETi (Aim 3). Our preliminary data demonstrate that the use of brief, low dose cyclophosphamide
(Cy) administered post-CT can dramatically prolong allograft survival by deleting effector T cells and
diminishing corneal neovascularization. Our novel two-pathway strategy additionally targeting the TNF receptor
super family 25 (TNFRSF25) using a fusion protein (TL1A-Ig) induces marked expansion of CD4+FoxP3+
Tregs systemically and within the ocular compartment. Importantly, these Tregs exhibit highly potent effector /
suppressive activity. Preliminary data demonstrates that epigenetic regulation using a bromodomain inhibitor
(BETi) can diminish pro-inflammatory cytokine production in vivo while simultaneously not interfering with Treg
expansion and function. Excitingly in the context of this proposal, BETi significantly diminished clinical changes
to the cornea when locally administered. We posit high-risk cornea is the ideal tissue to test this hypothesis
because there is opportunity to locally modulate immunity and inflammation and we will apply elegant in vivo
models to study, monitor and isolate antigen specific effector T cells and antigen specific Tregs using our
newly developed B6-Nur77GFPFoxP3RFP mice. The studies proposed in this application will provide a unique
opportunity to develop and test a 3-step combinatorial mechanism (CT-Cy, Treg, and BETi) for the
establishment of allograft tolerance to maintain permanent HRVCT. Significantly, because HRVCT behave
similarly to other vascularized organ transplants, work here can be applied to other tissues to induce transplant
acceptance. Therefore, we will begin to test our approach through Treg manipulation in skin transplants first,
using orthotopic mouse grafts and then continue by testing our strategy for translational application in humans
by using human skin allografts in an immunodeficient mouse model and utilizing novel human reagents (mAb
PTX-35) to manipulate human Treg cells. In total, this unique and powerful approach will bring toge...

## Key facts

- **NIH application ID:** 10133670
- **Project number:** 5R01EY030283-02
- **Recipient organization:** UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
- **Principal Investigator:** Robert Benjamin Levy
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $397,443
- **Award type:** 5
- **Project period:** 2020-04-01 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10133670

## Citation

> US National Institutes of Health, RePORTER application 10133670, Local regulation and deletion of T cells to induce tolerance and establish long-term survival of high-risk corneal transplants (5R01EY030283-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10133670. Licensed CC0.

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