Biology subjects

Ifergan, I.

Publications and source records attributed to Ifergan, I..

7 recordsLinked to original sources

bioRxiv2026

Poly(lactic-co-glycolic acid) immunomodulatory nanoparticles attenuate neuroinflammation and Alzheimer's disease-related pathology in 5xFAD mice

Alzheimers disease is characterized by progressive cognitive decline, amyloid-{beta} deposition, neuroinflammation, and neurodegeneration, yet effective and well-tolerated therapies remain limited. Because dysregulated myeloid responses are increasingly recognized as important drivers of disease progression, we investigated the therapeutic potential of poly(lactic-co-glycolic acid) immunomodulatory nanoparticles in the 5xFAD mouse model of amyloid-driven neurodegeneration. Poly(lactic-co-glycolic acid) immunomodulatory nanoparticles and fluorescently labeled particles displayed the expected size range and negative surface charge. After intraperitoneal administration, fluorescent particles were preferentially associated with myeloid cells in the blood, spleen, and brain, with greater uptake by brain myeloid populations in 5xFAD mice than in wild-type controls. Therapeutic treatment of 6.5-month-old 5xFAD mice, a stage at which behavioral abnormalities are already established, resulted in significant improvement in elevated plus maze behavior and a more modest improvement in Barnes maze performance. Flow cytometric analysis performed 9 weeks after the final treatment demonstrated persistent changes in brain immune composition, with the most prominent effects observed in P2RY12+ microglial populations, particularly the CD11c+ subset, and comparatively limited sustained effects in CD11b+P2RY12- myeloid cells. These changes were accompanied by reduced expression of activation- and disease-associated markers and lower pro-inflammatory cytokine production within microglial populations. Histological analysis further showed reduced cortical amyloid plaque burden, decreased CD68 immunoreactivity, and reduced neurodegeneration in treated 5xFAD mice. Together, these findings show that systemically administered poly(lactic-co-glycolic acid) immunomodulatory nanoparticles produce durable behavioral, immunological, and pathological benefits in 5xFAD mice and support further investigation of this biodegradable myeloid-targeted platform as a therapeutic strategy for Alzheimers disease.

neuroscience↗

bioRxiv2026

Canonical WNT Ligands Produced by Regulatory T Cells Restrain Effector CD4+ T Cell Responses

Regulatory T cells (Tregs) are essential for maintaining immune homeostasis by suppressing excessive activation of effector T cells. Although several mechanisms of Treg-mediated suppression have been described, the molecular signals that contribute to this regulation remain incompletely understood. WNT signaling, best known for its roles in development and tissue homeostasis, has recently emerged as an important regulator of immune function, but its contribution to Treg-mediated immune suppression is largely unknown. Here, we show that Tregs preferentially express multiple canonical WNT ligands, including WNT2B, WNT3, WNT7B, and WNT10B, compared with conventional CD4+ T cells. These WNT proteins were detected intracellularly in Tregs, and WNT2B and WNT3 were actively secreted into culture supernatants. Conventional CD4+ T cells expressed Frizzled receptors capable of sensing these ligands. Pharmacological inhibition of canonical WNT signaling using the antagonist mDKK-1 enhanced CD4+ T cell activation and proliferation and increased pro-inflammatory cytokine expression, while anti-inflammatory IL-10 remained unchanged. Together, these findings identify Tregs as a source of canonical WNT ligands and suggest that Treg-derived WNT signaling contributes to the suppression of effector CD4+ T cell responses. This work reveals a previously underappreciated pathway through which Tregs regulate immune activity and identifies WNT signaling as a potential target for modulating inflammatory immune responses.

immunology↗

bioRxiv2026

Dual Role of Ninjurin-1 in Myeloid Cell Adhesion and Inflammation in Relapse-Remitting EAE

Nerve Injury-Induced Protein 1 (Ninjurin-1) is an adhesion molecule implicated in inflammation and tissue injury, yet its role in neuroinflammatory diseases such as multiple sclerosis (MS) remains poorly defined. Here, we identify Ninjurin-1 as a key mediator of immune activation and CNS infiltration in relapsing-remitting experimental autoimmune encephalomyelitis (RR-EAE), a model of relapsing-remitting MS (RRMS). Using flow cytometry, gene-expression profiling, and in vivo peptide blockade, we show that Ninjurin-1 is markedly upregulated on CNS-infiltrating myeloid cells during disease progression. Ninjurin-1 myeloid cells display a dual function, as both an adhesion molecule and a marker of inflammatory activation, characterized by increased antigen presentation, cytokine production, and transcriptional enrichment for genes regulating adhesion, migration, and innate immune signaling. Importantly, therapeutic blockade of Ninjurin-1 significantly reduced clinical severity, CNS immune infiltration, and demyelination in RR-EAE. These findings uncover a previously unrecognized role for Ninjurin-1 in myeloid-driven neuroinflammation and highlight its potential as a therapeutic target for relapsing-remitting MS.

neuroscience↗

bioRxiv2025

A novel interoceptive subfornical organ to infralimbic cortex circuit relays airway inflammation effects on fear extinction

There is growing interest in the impact of internal body states on the brain and behavior. The detrimental effects of chronic lung inflammation on mental health are well recognized, however, underlying mechanisms are not known. Here, using a murine model of allergic asthma we report compromised fear extinction in mice with severe but not mild airway inflammation (AI); an effect abolished by anti-interleukin-17A (IL-17A) antibodies. Investigation of innate immune cells, microglia as-well-as transcriptomic signatures in the subfornical organ (SFO), a brain interoceptive node lacking a traditional blood-brain-barrier, revealed significant alterations in severe AI mice. IL-17 Receptor A (IL-17RA) was expressed in SFO microglia and upregulated in severe AI mice. Notably, ablation of microglial IL-17RA improved fear extinction in severe AI mice. Furthermore, we identified direct SFO projections to the infralimbic (IL) cortex, a key area regulating extinction. Importantly, chemogenetic inhibition of the SFO-IL circuit led to improved fear extinction in severe AI mice. Collectively, we report a unique body-to-brain interoceptive mechanism engaging the SFO and an SFO-to-IL circuit, through which airway inflammatory mediators compromise fear extinction. Beyond asthma, our findings are relevant to other pulmonary pathologies (e.g. bacterial pneumonia, ARDS, COVID-19) highlighting a risk for cortical dysfunction and fear pathologies such as PTSD.

neuroscience↗

bioRxiv2025

Wnt-Activated Immunoregulatory Myeloid Cells Prevent Relapse in Experimental Autoimmune Encephalomyelitis and Offer a Potential Therapeutic Strategy for Multiple Sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by recurrent inflammatory relapses and neurodegeneration. Myeloid cells play a critical role in shaping the inflammatory environment and influencing disease progression. Here, we demonstrate that activation of the Wnt signaling pathway reprograms myeloid cells into an immunoregulatory phenotype, leading to reduced neuroinflammation and disease severity. Using both experimental autoimmune encephalomyelitis (EAE) and human-derived myeloid cells, we show that Wnt agonist treatment promotes the expression of inhibitory molecules such as PD-L1 and PD-L2, suppressing pro-inflammatory responses. In the chronic and relapsing-remitting EAE models, Wnt activation significantly reduced disease severity, immune cell infiltration into the CNS, and pathogenic T cell responses. Notably, in relapsing-remitting EAE, Wnt treatment prevented new relapses in a PD-L1-dependent manner, highlighting the crucial role of myeloid cell-mediated immune regulation. These findings reveal a previously unrecognized role for Wnt signaling in myeloid cell immunoregulation and suggest that targeting this pathway could provide a novel therapeutic strategy for MS and other autoimmune diseases.

immunology↗

bioRxiv2023

Microglia-derived TGF-β1 ligand maintains microglia homeostasis via autocrine mechanism and is critical for normal cognitive function in adult mouse brain

While TGF-{beta} signaling is essential for microglial function, the cellular source of TGF-{beta} ligand and its spatial regulation remains unclear in the adult CNS. Our data support that microglia, not astrocytes or neurons, are the primary producers of TGF-{beta}1 ligands needed for microglial homeostasis. Microglia (MG)-Tgfb1 inducible knockout (iKO) leads to the activation of microglia featuring a dyshomeostatic transcriptomic profile that resembles disease-associated microglia (DAMs), injury-associated microglia, and aged microglia, suggesting that microglial self-produced TGF-{beta}1 ligands are important in the adult CNS. Interestingly, astrocytes in MG-Tgfb1 iKO mice show a transcriptome profile that closely aligns with A1-like astrocytes. Additionally, using sparse mosaic single-cell microglia iKO of TGF-{beta}1 ligand, we established an autocrine mechanism for TGF-{beta} signaling. Importantly MG-Tgfb1 iKO mice show cognitive deficits, supporting that precise spatial regulation of TGF-{beta}1 ligand derived from microglia is critical for the maintenance of brain homeostasis and normal cognitive function in the adult brain.

neuroscience↗

bioRxiv2020

CRISPR Screen in Regulatory T Cells Reveals Ubiquitination Modulators of Foxp3

Regulatory T cells (Tregs) are required to control immune responses and maintain homeostasis but are a significant barrier to anti-tumor immunity1. Conversely, Treg instability, characterized by loss of the master transcription factor Foxp3 and acquisition of pro-inflammatory properties2, can promote autoimmunity and/or facilitate more effective tumor immunity3,4. A comprehensive understanding of the pathways that regulate Foxp3 could lead to more effective Treg therapies for autoimmune disease and cancer. Despite improved functional genetic tools that now allow for systematic interrogation, dissection of the gene regulatory programs that modulate Foxp3 expression has not yet been reported. In this study, we developed a CRISPR-based pooled screening platform for phenotypes in primary mouse Tregs and applied this technology to perform a targeted loss-of-function screen of [~]490 nuclear factors to identify gene regulatory programs that promote or disrupt Foxp3 expression. We discovered several novel modulators including ubiquitin-specific peptidase 22 (Usp22), Ataxin 7 like 3 (Atxn7l3) and ring finger protein 20 (Rnf20). Members of the deubiquitination module of the SAGA chromatin modifying complex, Usp22 and Atxn7l3, were discovered to be positive regulators that stabilized Foxp3 expression; whereas the screen suggested Rnf20, an E3 ubiquitin ligase, is a negative regulator of Foxp3. Treg-specific ablation of Usp22 in mice reduced Foxp3 protein and created defects in their suppressive function that led to spontaneous autoimmunity but protected against tumor growth in multiple cancer models. Foxp3 destabilization in Usp22-deficient Tregs could be rescued by ablation of Rnf20, revealing a reciprocal ubiquitin switch in Tregs. These results reveal novel modulators of Foxp3 and demonstrate a screening method that can be broadly applied to discover new targets for Treg immunotherapies for cancer and autoimmune disease.

immunology↗