# Regulatory Mechanisms Controlling TFH Responses in Lupus

> **NIH NIH R01** · HOSPITAL FOR SPECIAL SURGERY · 2020 · $387,200

## Abstract

ABSTRACT
Despite significant advances in our understanding of the pathogenic mechanisms responsible for the
development of Systemic Lupus Erythematosus (SLE) many patients with SLE continue to live with poorly
controlled disease. A major roadblock in our ability to develop novel treatments for SLE is the significant
heterogeneity that accompanies this disorder, which is partly due to the complexity of T helper and regulatory T
cell subsets. Amongst TH subsets, TFH cells play a major role in lupus pathogenesis due to their crucial role in
driving humoral responses. TFH cell development requires Bcl6 and overexpression of Bcl6 is sufficient to drive
TFH differentiation indicating that tight control of Bcl6 expression is essential to ensure proper regulation of TFH
cell numbers. Using mice lacking DEF6 and SWAP-70 (DKO mice), two members of a unique family of immune
regulators whose absence leads to the spontaneous development of lupus, we have recently uncovered a new
mechanism controlling the expression of Bcl6 and the expansion of TFH cells. Indeed DKO mice exhibit an
accumulation of TFH cells due to aberrant translation of Bcl6. Increased translation of Bcl6 in DKO TH cells is the
result of enhanced mTORC1 activation secondary to aberrant control of a pathway regulating the assembly of a
raptor-p62-TRAF6 complex. A proteomic approach demonstrated that enhanced Bcl6 translation in DKO TH
cells is accompanied by dysregulated expression of a selected number of proteins. In addition to cell-intrinsic
abnormalities in TFH cells, imbalances in the coordinated development of TFH cells and its specialized effector
Treg subset, follicular regulatory T (TFR) cells, can also promote autoimmunity. An analysis of the Treg
population in DKO mice has revealed a defective expansion of TFR cells but a robust accumulation of non-TFR
effector Tregs. In this proposal we will explore the hypothesis that an aberrant ability of TFH cells to employ
translational mechanisms coupled with defects in the TFR cell subset can lead to systemic autoimmunity. We will
also investigate the related hypothesis that while defects in TFR cells can fuel aberrant autoantibody production,
the simultaneous expansion of non-TFR effector Tregs can help limit the tissue damage promoted by these
autoAbs. Specifically we will: 1) Delineate the regulation and role of mTORC1-dependent translational
programming in TFH cells, and 2) Dissect the pathways controlling effector Treg subsets in lupus. While
transcriptional abnormalities in SLE have been extensively investigated, the impact of aberrant translational
mechanisms on the function of lupus T cells has received little attention. These studies will thus provide critical
information on a new area of investigation and potentially uncover novel targets for therapeutic intervention. A
better understanding of the involvement of different Treg subsets in lupus could furthermore provide new
insights into the heterogeneity that accompanies this disea...

## Key facts

- **NIH application ID:** 9937661
- **Project number:** 5R01AR070146-05
- **Recipient organization:** HOSPITAL FOR SPECIAL SURGERY
- **Principal Investigator:** ALESSANDRA B PERNIS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $387,200
- **Award type:** 5
- **Project period:** 2016-07-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9937661

## Citation

> US National Institutes of Health, RePORTER application 9937661, Regulatory Mechanisms Controlling TFH Responses in Lupus (5R01AR070146-05). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9937661. Licensed CC0.

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