Spoerl, Silvia

Rationale: Oral squamous cell carcinoma (OSCC) carries a poor prognosis despite advances in multimodal therapy. Nanomedicine represents a compelling strategy to enhance targeted drug delivery and improve therapeutic outcomes. Here, we investigated sEV-mediated delivery of curcumin as a novel therapeutic approach for OSCC. Methods: Small extracellular vesicles (sEVs) were isolated from Jurkat cells by size-exclusion chromatography and loaded with curcumin via sonication to generate JCsEV. Functional effects were assessed in vitro using wound healing, transwell invasion, and metabolic activity assays across multiple cancer cell lines. Therapeutic efficacy in vivo was evaluated in the 4-nitroquinoline 1-oxide (4-NQO) immunocompetent murine model of oral carcinogenesis. Female C57BL/6J mice received intraperitoneal treatment for four weeks with PBS, free curcumin, unloaded JsEV, or JCsEV. Tumor number, tumor burden, and body weight changes were assessed at the experimental endpoint. Results: In vitro, JCsEV significantly inhibited tumor cell migration, invasion, and metabolic activity compared with controls (p < 0.05). In vivo, treatment with JCsEV significantly reduced tumor number and tumor burden in the 4-NQO model (p < 0.01). In addition, body weight loss was reduced in JCsEV-treated mice compared with controls. Conclusion: sEV-mediated delivery of curcumin effectively suppresses tumor progression in experimental OSCC. These findings establish proof-of-concept for sEV-based nanomedicine as a therapeutic strategy for OSCC and provide a compelling rationale for further translational investigation of sEVs as drug delivery platforms.

Giant cell arteritis (GCA) is a granulomatous and occlusive vasculitis that causes blindness, stroke, and aortic aneurysm. CD4+ T cells are selectively activated in the adventitia of affected arteries. In human GCA artery–severe combined immunodeficiency (SCID) mouse chimeras, depletion of CD83+ dendritic cells (DCs) abrogated vasculitis, suggesting that DCs are critical antigen-presenting cells in GCA. Healthy medium-size arteries possessed an indigenous population of DCs at the adventitia–media border. Adoptive T cell transfer into temporal artery–SCID mouse chimeras demonstrated that DCs in healthy arteries were functionally immature, but gained T cell stimulatory capacity after injection of lipopolysaccharide. In patients with polymyalgia rheumatica (PMR), a subclinical variant of GCA, adventitial DCs were mature and produced the chemokines CCL19 and CCL21, but vasculitic infiltrates were lacking. Human histocompatibility leukocyte antigen class II–matched healthy arteries, PMR arteries, and GCA arteries were coimplanted into SCID mice. Immature DCs in healthy arteries failed to stimulate T cells, but DCs in PMR arteries could attract, retain, and activate T cells that originated from the GCA lesions. We propose that in situ maturation of DCs in the adventitia is an early event in the pathogenesis of GCA. Activation of adventitial DCs initiates and maintains T cell responses in the artery and breaks tissue tolerance in the perivascular space.