bioRxiv Science⌕ Search

Biology subjects

Solt, L.

Publications and source records attributed to Solt, L..

3 recordsLinked to original sources

REV-ERBα/β Targeting Transcriptionally Reprograms HIV-Infected CD4+ T-Cells for Increased Viral Reactivation but Limited Virion Spread

The circadian clock repressors REV-ERB/{beta} control rhythmic gene expression and inhibit HIV-1 transcription. Whether REV-ERB/{beta} modulate the HIV-1 replication cycle beyond transcription remains unknown. Here, we demonstrate that memory CD4+ T-cells predominantly express the REV-ERB{beta} isoform ex vivo and that T-cell receptor (TCR) triggering downregulates both REV-ERB/{beta} expression, with levels of REV-ERB/{beta} mRNA being lower in ART-treated people with HIV (PWH) receiving antiretroviral therapy (ART) compared to people without HIV (PWoH) before/after TCR triggering. In single-round infection, the REV-ERB/{beta} antagonist SR8278 facilitated HIV-1 reverse transcription, integration, and intracellular HIV-p24 expression, but limited virion release. Moreover, SR8278 downregulated CCR5 mRNA expression, inhibited R5-tropic HIV-1 replication in vitro, and limited viral outgrowth in CD4+ T-cells from ART-treated PWH. Finally, genome-wide RNA-sequencing and functional validations revealed HIV-1 restriction/dependency factors that represent novel putative REV-ERB/{beta} targets. Thus, pharmacological inhibition of REV-ERB/{beta} uniquely combines a latency reversal activity with the inhibition of progeny virion spread.

immunology↗

Selective Glucocorticoid Receptor Modulators of Immune Checkpoint Function

Glucocorticoids (GCs) coordinate immunity, inflammation, and metabolism through allosteric regulation of the glucocorticoid receptor (GR) transcription factor. GCs are indispensable anti-inflammatory drugs yet linking specific ligand-receptor structural states to specific biological outcomes has remained a major barrier to designing safer, more selective therapies. Using structure-based design, we developed selective glucocorticoid receptor modulators (SGRMs) of immune function by extending a steroidal scaffold from the ligand-binding pocket into an adjacent solvent channel. These SGRMs suppressed T cell pro-inflammatory cytokines and promoted differentiation of memory precursor T cells while showing minimal induction of M2 macrophage polarization or T cell checkpoint proteins PD-1 and CTLA-4, all key targets of immunotherapy. Molecular dynamics simulations revealed that solvent-channel substituents function as a lever arm to drive dynamic oscillations in the steroid core, thereby allosterically tuning GR activity states. Systematic perturbation of immune cells with a graded series of ligands enabled a ligand perturbation with machine learning (LPML) framework to map coregulated responses across cell types and identified effector T cell gene networks tightly coupled with immune checkpoint induction. This approach outlines a general strategy for decoding the logic of allosteric drug action, enabling the rational design of SGRMs with tailored immunomodulatory profiles.

systems biology↗

Negative regulation of TH17-mediated inflammation by the nuclear receptor REV-ERBβ

TH17 cells play a central role in several human autoimmune diseases. We and others reported the nuclear receptor, REV-ERB, as a cell-intrinsic repressor of TH17-mediated pathogenicity. REV-ERB{beta}, REV-ERBs closely related family member, is thought to be functionally redundant to REV-ERB, which we sought to explore in TH17-mediated immunity. Our data indicate that deletion of REV-ERB{beta} enhances TH17-mediated pro-inflammatory cytokine expression and exacerbated disease in mouse models of multiple sclerosis and colitis. RNA-sequencing indicates REV-ERB{beta} and REV-ERB do not have similar transcriptional profiles. REV-ERB{beta} does not appear to regulate gene expression through interaction with the classic co-repressor NCoR1, which is in contrast to REV-ERB in TH17 cells, nor does it utilize heme, its known endogenous ligand for its repressive functions. Our results establish that while REV-ERB{beta} also acts as a negative regulator of TH17-cell function and pathogenicity, it does so in a manner that is non-redundant, independent, and unique to REV-ERB.

immunology↗