Genital herpes, caused by herpes simplex virus 2 (HSV-2), remains a prevalent sexually transmitted infection with no available vaccine. Effective local immunity, mediated in part by tissue-resident memory T cells (TRM cells) and luminal antibodies, provides immediate viral control. Here, we developed bioactive enhanced adjuvant chemokine oligonucleotide nanoparticles (BEACONs) formed via electrostatic interactions between CpG oligodeoxynucleotides (CpG ODNs) and the chemokine CXCL9. This adjuvant enhances antigen-presenting cell engagement and innate immune signaling, promotes CD8 T cell recruitment, and reduces local neutrophilic inflammation relative to CpG ODNs. After intramuscular priming with HSV-2 glycoprotein-encoding messenger RNA-lipid nanoparticles, vaginal boosting with cognate recombinant glycoprotein and BEACONs improved protection against HSV-2 by increasing local CD8 TRM cell populations and mucosal antibody responses. Vaccine-mediated protection required local delivery of both antigen and adjuvant and was reduced by CD8 T cell or B cell depletion. These findings support engineered mucosal adjuvants for vaccines targeting genital herpes and other sexually transmitted infections.

Abstract Metabolic dysfunction-associated steatohepatitis (MASH) is becoming a major driver of hepatocellular carcinoma (HCC). Caspase-1 (CASP1), a central component of the inflammasome complex, has been implicated in liver disease, but its specific role in MASH-associated HCC (MASH-HCC) remains unclear. Here, we investigated the functional role of CASP1 in MASH HCC using Casp1 knockout ( Casp1 -/- ) mice in a Western diet-induced de novo tumorigenesis model and an orthotopic model. We characterized the tumor immune microenvironment (TIME) and performed mechanistic analyses using flow cytometry, single-cell RNA sequencing (scRNA seq), pharmacological inhibition, CRISPR–Cas9 gene editing and functional immune assays. Casp1-/- mice exhibited significantly enhanced MASH-HCC growth and an immunosuppressive TIME. Mechanistically, loss of CASP1 led to increased phosphorylation of TANK binding kinase 1 (TBK1), promoting ubiquitination and proteasomal degradation of peroxisome proliferator activated receptor alpha (PPARα). TBK1 activity protected HCC cells from cytokine-mediated, RIPK1-dependent cell death. Conversely, activation of PPARα suppressed TBK1 phosphorylation and sensitized HCC cells to cytokine-induced cell death. Importantly, pharmacological inhibition of TBK1 markedly suppressed tumor growth in Casp1 -/- mice and restored antitumor immunity. These findings identify a non-canonical, tumor-suppressive role for CASP1 in MASH-HCC through regulation of TBK1 and PPARα. Targeting this pathway may represent a promising 40 therapeutic strategy to suppress tumor growth and enhance antitumor immunity in this context

Fibroblasts and immune cells coordinate tissue regeneration and necessary scarring after injury. In the brain, fibroblasts are border-enriched cells whose dynamic molecular states and immune interactions after injury remain unclear1. Here we define the shared fibroblast-immune response to brain injury. Early profibrotic myofibroblasts develop from pre-existing brain fibroblasts and infiltrate brain lesions, orchestrated by fibroblast TGFβ signalling, profibrotic macrophages and microglia, and perilesional glia. Myofibroblasts transition into several late fibroblast states, including lymphocyte-interactive fibroblasts. Interruption of the early myofibroblast state exacerbated sub-acute brain injury, tissue loss and secondary neuroinflammation, with increased mortality in the transient middle cerebral artery occlusion stroke model. Disruption of late lymphocyte-fibroblast niches via selective loss of fibroblast chemokine CXCL12 led to late brain-specific innate inflammation and lymphocyte dispersal with increased IFNγ production. These data indicate the response to brain injury is coordinated by evolving temporal and spatial fibroblast states that limit functional tissue loss and chronic neuroinflammation.
© 2025. The Author(s).

Immune checkpoint blockade (ICB) has revolutionized cancer treatment. Unfortunately, the inability of lymphocytes to infiltrate the tumor nest, a phenomenon known as immune exclusion, drastically limits ICB responsiveness. Analyzing the immune landscape of matched pre- and early on-treatment biopsies of patients with melanoma undergoing ICB therapy, we observed a significant increase in cytotoxic NK cells in early on-treatment biopsies from nonresponders. Spatial multiomic analyses revealed that, although NK cells colocalized with CD8+ T cells within the tumor bed in responding lesions, they were excluded from the tumor parenchyma in nonresponding lesions. Strikingly, pharmacologic depletion of NK cells in a unique melanoma mouse model exhibiting an immune-excluded phenotype unleashed immune infiltration of the tumor core and tumor clearance upon ICB exposure. Mechanistically, we show that NK cells are actively recruited to immune-excluded areas upon ICB exposure via the chemokine receptor CX3CR1 to suppress tumor infiltration and antitumor function of CD8+ T cells.
Immune exclusion is responsible for intrinsic resistance to ICB in about half of nonresponder patients. Our unexpected observation that targeting NK cell biology unleashes the recruitment and antitumor activity of CD8+ T cells in tumors with an immune-excluded phenotype offers a potential therapeutic avenue for this large patient population. See related commentary by Galvez-Cancino et al., p. 1777 See related article by Song et al., p. 1835.
©2025 The Authors; Published by the American Association for Cancer Research.

Cannabinoid receptor 1 (CB1) has been implicated in multiple inflammatory diseases by regulating pro-inflammatory mediators or altering immune cell polarization. However, the expression and direct functional role of CB1 in T cells remain largely unexplored. Here, we demonstrate that primary murine T cells express CB1 and that its novel agonist, BI-5756, directly increases the frequencies of regulatory T cells (Tregs) in primary murine pan T cells after activation. In addition, BI-5756 exhibits an in vivo protective effect against graft-versus-host disease (GvHD), an allogeneic T cell-mediated inflammatory complication after allogeneic hematopoietic cell transplantation (allo-HCT), resulting in an improved overall survival with enhanced platelet recovery and reconstitution of bone marrow-derived B and T cells. BI-5756 also directly suppresses tumor cell growth and upregulates MHC I, MHC II, and CD80 on tumor cells, which may subsequently enhance T cell-mediated anti-tumor responses in mixed lymphocyte reaction with A20 cells. The ability of BI-5756 to increase Tregs was significantly abrogated by rimonabant, a potent and selective CB1 antagonist, suggesting that the immunomodulatory effect of BI-5756 is mediated via CB1. In summary, BI-5756, a potent CB1 agonist, increases Tregs while preserving anti-tumor responses in vitro and effectively reduces GvHD in vivo.