# A Novel Human Regulatory B Cell Subset

> **NIH NIH R21** · VERSITI BLOOD HEALTH, INC. · 2020 · $208,750

## Abstract

Autoimmune diseases are the second highest cause of chronic illness and the number one cause of morbidity
in women in the United States. At least 100 chronic autoimmune diseases have been described that affect over
50 million Americans. As a class of disease, the annual health care burden for autoimmunity is estimated at
over $100 billion. Most autoimmune diseases have limited treatment options and cannot be cured. One
commonality to all autoimmune disease is the breakdown in immunological tolerance that lets the body's own
immune system attack its tissues. While many tolerance mechanisms exist, a role for CD4+Foxp3+ T regulatory
cells (Treg) in keeping self-immune responses in check is likely an essential tolerance mechanism for all
autoimmune diseases. Thus Treg are considered a strong therapeutic target for the treatment of autoimmunity.
To date there are no FDA approved adoptive Treg immunotherapies. Thus alternative approaches must be
developed to harness the therapeutic power of Treg. To that end, we have discovered a new mature B cell
subset that plays an essential role in the maintenance of Treg homeostasis. Using experimental autoimmune
encephalomyelitis (EAE), the mouse model of the human central nervous system autoimmune disease multiple
sclerosis, we have shown that in the absence of B cells, mice cannot recover from the signs of disease and
Treg numbers are significantly reduced. Upon reconstitution of B cells, Treg numbers significantly increased
and the mice recovered from EAE. These data demonstrate that a population of regulatory B cells (Breg) exists
that attenuate inflammation indirectly through Treg. Because of their IgDlow/- phenotype, we have named them
them B cell IgD Low or BDL. We will test the hypothesis: Single cell transcriptomic analysis on mouse BDL will
define a distinct cell cluster with a phenotypic and regulatory gene expression profile that can be used to
identify and track hBDL.

## Key facts

- **NIH application ID:** 9861220
- **Project number:** 5R21AI145323-02
- **Recipient organization:** VERSITI BLOOD HEALTH, INC.
- **Principal Investigator:** Bonnie N Dittel
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $208,750
- **Award type:** 5
- **Project period:** 2019-02-06 → 2022-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9861220

## Citation

> US National Institutes of Health, RePORTER application 9861220, A Novel Human Regulatory B Cell Subset (5R21AI145323-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9861220. Licensed CC0.

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