Disease-modifying therapies (DMTs) that prevent immune cell infiltration into the brain have demonstrated efficacy in multiple sclerosis (MS) treatment. However, their unpredictable adverse effects necessitate the development of safer therapeutic alternatives. The choroid plexus (ChP) functions as a crucial barrier against immune cell invasion, and previous studies have shown that preventing immune cell infiltration across the ChP reduces brain lesion in MS animal models. Understanding ChP barrier regulation is therefore essential for identifying novel therapeutic targets for MS. Here, we explored the role of Ste20-related proline/alanine-rich kinase (SPAK) in experimental autoimmune encephalomyelitis (EAE).
We examined the expression patterns of SPAK signaling in ChP using immunofluorescence in the EAE model. To investigate the roles of SPAK, matrix metalloproteinase (MMP) 2 and MMP9 in EAE pathology, we performed ChP-specific gene manipulation via intracerebroventricular (ICV) injection of recombinant adeno-associated virus 2/5 (rAAV2/5). T cell infiltration into the central nervous system (CNS) was analyzed using CD4 immunostaining and flow cytometry. We employed cell immunofluorescence, transwell assays, and rescue experiments in vitro to study SPAK's effects on ChP epithelial barrier integrity. We also evaluated the protective effects of SPAK-Na-K-2Cl cotransporter-1 (NKCC1) inhibitors (ZT-1a and bumetanide) on immune invasion and demyelination during EAE using pharmacological approaches.
Following EAE induction, we observed progressive increases in both total and phosphorylated SPAK levels in ChP epithelium. Notably, ChP-specific SPAK knockdown significantly reduced T cell invasion and ameliorated EAE pathology, while SPAK overexpression exacerbated these effects. Bulk RNA sequencing and subsequent qPCR validation revealed that SPAK knockdown decreased the expression of MMP2 and MMP9, MMPs that compromise barrier integrity by degrading tight junction proteins. In vitro studies demonstrated that SPAK overexpression impaired ChP barrier function through the activator protein-1 (AP-1)-MMP2/9-zonula occludens-1 (ZO-1) axis. Furthermore, ChP-specific knockdown of either MMP2 or MMP9 protected against EAE pathology. Additionally, we identified SPAK-NKCC1 antagonists (bumetanide and ZT-1a) as promising therapeutic candidates for MS/EAE treatment.
Our findings demonstrate that targeting ChP-SPAK signaling represents a novel therapeutic strategy for MS treatment.
© 2025. The Author(s).

Adenosine A2A receptor (A2AR) antagonists have been consistently demonstrated to protect against multiple sclerosis (MS) pathology, but A2AR knockout (A2AR-/-) mice exhibit exacerbated immune injury, raising concerns regarding the use of A2AR antagonists for MS treatment. Here, we revealed the critical involvement of A2AR-mediated interactions between Th1+ T cells and the choroid plexus (ChP) epithelium in the pathology of experimental autoimmune encephalomyelitis (EAE).
We assessed the effects of A2AR knockout on ChP gateway activity and the interferon gamma (IFN-γ)-secreting capacity of Th1+ T cells in an EAE model by immunofluorescence, qPCR and flow cytometry (FCM). We also investigated the effects of A2AR-mediated interactions between Th1+ T cells and the ChP epithelium on ChP gateway activity in vivo via intracerebroventricular (ICV) injection of Th1+ T cells and in vitro via coculture of ChP epithelial cells and splenic Th1+ T cells. We further knocked down IFN-γ receptor 1 (IFNGR1) specifically in the ChP of A2AR-/- mice via ICV injection of AAV2/5-shRNA (IFNGR1) to disrupt the interactions between Th1+ T cells and the ChP epithelium and thus assess the roles of these interactions in the development of EAE pathology.
A2AR knockout disrupted the ChP barrier and increased T-cell infiltration across the ChP in EAE model mice. Coculture of splenic Th1+ T cells and ChP epithelial cells revealed that A2AR knockout in ChP epithelial cells strengthened the ChP barrier and attenuated T-cell migration, whereas A2AR knockout in Th1+ T cells increased the accumulation of Th1+ T cells in the ChP via the secretion of IFN-γ. Consistent with the coculture results, ICV injection of activated splenic Th1+ T cells from A2AR-/- mice increased the accumulation of T cells in the ChP to a greater extent than did injection of Th1+ T cells from A2AR+/+ mice. This effect was due to the increased secretion of IFN-γ in A2AR-/- mice compared with A2AR+/+ mice. Finally, ChP-specific knockdown of IFNGR1 attenuated A2AR knockout-induced T-cell infiltration, brain inflammation and EAE pathology.
A2AR-mediated interactions between Th1+ T cells and the ChP epithelium via the secretion of IFN-γ from CD4+ T cells and the binding IFN-γ to IFNGR1 in the ChP epithelium control immune cell invasion and the development of EAE pathology in A2AR-/- mice.
© 2025. The Author(s).

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to systemic and articular bone loss by activating bone resorption and suppressing bone formation. Despite current therapeutic agents, inflammation-induced bone loss in RA continues to be a significant clinical problem due to joint deformity and lack of articular and systemic bone repair. Here, we identify the suppressor of bone formation, Schnurri-3 (SHN3), as a potential target to prevent bone loss in RA. SHN3 expression in osteoblast-lineage cells is induced by proinflammatory cytokines. Germline deletion or conditional deletion of Shn3 in osteoblasts limits articular bone erosion and systemic bone loss in mouse models of RA. Similarly, silencing of SHN3 expression in these RA models using systemic delivery of a bone-targeting recombinant adenoassociated virus protects against inflammation-induced bone loss. In osteoblasts, TNF activates SHN3 via ERK MAPK-mediated phosphorylation and, in turn, phosphorylated SHN3 inhibits WNT/β-catenin signaling and up-regulates RANKL expression. Accordingly, knock-in of a mutation in Shn3 that fails to bind ERK MAPK promotes bone formation in mice overexpressing human TNF due to augmented WNT/β-catenin signaling. Remarkably, Shn3-deficient osteoblasts are not only resistant to TNF-induced suppression of osteogenesis, but also down-regulate osteoclast development. Collectively, these findings demonstrate SHN3 inhibition as a promising approach to limit bone loss and promote bone repair in RA.

Glucose, the critical energy source in the human body, is considered a potential risk factor in various autoimmune diseases when consumed in high amounts. However, the roles of glucose at moderate doses in the regulation of autoimmune inflammatory diseases and CD4+ T cell responses are controversial. Here, we show that while glucose at a high concentration (20% w/v) promotes intestinal inflammation, it suppresses colitis at a moderate dose (6% w/v), which increases the proportion of intestinal regulatory T (Treg) cells but does not affect effector CD4+ T cells. Glucose treatment promotes Treg cell differentiation but it does not affect Treg stability. Feeding glucose alters gut microbiota compositions, which are not involved in the glucose induction of Treg cells. Glucose promotes aryl hydrocarbon receptor (AhR) activation to induce Treg polarization. These findings reveal the different effects of glucose at different doses on the intestinal immune response.
© 2022 The Author(s).

Peptides, but not whole protein, elicit an allergic reaction since food allergens should be consumed by digestion. In this study, we explored the remaining peptides after simulated digestion of cow's milk in order to search for β-lactoglobulin (BLG)-derived peptides that could play an immunomodulatory role. As a major allergen in milk, BLG-derived peptides, 109 in total, were identified both from simulated infant and adult digestion in vitro. These peptides were mainly located in four regions, and they were synthesized as five peptides, namely, BLG1-14, BLG24-35, BLG40-60, BLG82-101, and BLG123-139. Then, the effect of peptides on the Caco-2 cell's transport absorption, the co-stimulatory molecules of DC, and the T-cell phenotype was explored. The results suggested all peptides showed better transport absorption capacity with the apparent permeability coefficient higher than 2 × 10-6 cm·s-1. The ability of BLG40-60 for promoting lamina propria-derived DC cell (LPDC) maturation was observed by the increase in MHC II. Moreover, BLG1-14 and BLG40-60 directed activation of T lymphocytes towards a Th1 phenotype. This is the first report of the immunomodulatory potential of peptides in the sensitization of allergic reaction, and one peptide, BLG40-60, was regarded as an immunomodulatory peptide, one that should be further explored in an animal model in depth.