Biology subjects

Raghuram, S.

Publications and source records attributed to Raghuram, S..

3 recordsLinked to original sources

bioRxiv2026

Targeting NF-κB epigenetic activation and DNA repair deficiency in G34-mutant pediatric diffuse hemispheric glioma with nanoparticles combining PARP inhibition and immune stimulation mediated by CpG dinucleotides

Diffuse hemispheric gliomas (DHGs) are highly aggressive and infiltrative CNS tumors that are refringent to treatment, and with a 5-year overall survival of around 20%. A fraction of DHGs is driven by mutations in the histones H3.1 and H3.3. In this study, we demonstrate that the expression of histone H3.3 glycine 34 to arginine mutations (H3.3-G34R) result in the epigenetic and transcriptional activation of the NF-{kappa}B signaling pathway in DHG. To target this vulnerability, we designed high density lipoprotein (HDL) nanoparticles loaded with unmethylated CpG dinucleotides, which mimic the immune stimulatory activity of bacterial DNA. CpG are recognized by Toll-like receptor 9 (TLR9), activating the NF-{kappa}B signaling. The CpG-mediated NF-{kappa}B activation results in the release of immuno-stimulating cytokines that promote an antitumoral response. As we previously established that G34-mutant DHGs are characterized by DNA repair impairment, we combined CpG dinucleotides with a PARP (poly (ADP-ribose) polymerase) inhibitor, olaparib, in the HDL nanoparticles.

cancer biology↗

bioRxiv2025

Reprogramming the Immune Suppressive Tumor Microenvironment in Glioma Enhances the Efficacy of Immune-Mediated Gene Therapy

Gliomas account for ~80% of primary malignant brain tumors. Many CNS WHO grade 2-3 and some grade 4 gliomas harbor mutant isocitrate dehydrogenase 1 (mIDH1), which causes a gain of function mutation (IDH1 R132H) leading to the production of 2-hydroxyglutarate (2HG). Mutant IDH1-induced 2HG, through epigenetic reprogramming elicits an immune-permissive tumor microenvironment (TME). An immunosuppressive mechanism in the glioma TME involves adenosine production via the ectoenzyme CD73. This study investigates mIDH1s influence on CD73 expression and adenosine levels. We demonstrate that mIDH1 glioma cells exhibit reduced CD73 expression, driven by DNA hypermethylation, leading to reduced adenosine levels. Since wtIDH1 gliomas have high CD73 expression, we evaluated CD73 blockade as an immunotherapy target. We show that CD73 inhibition used as monotherapy, did not improve survival in wtIDH1 glioma-bearing mice. However, when combined with immune-stimulatory Ad-TK (adenoviral vectors encoding herpes simplex virus thymidine kinase) and Ad-Flt3L (adenoviral vectors encoding FMS-like tyrosine kinase 3 ligand) gene therapy, CD73 blockade significantly enhanced therapeutic efficacy and increased anti-glioma effector T cell activity. These findings reveal that CD73 inhibition used in combination with immune stimulatory Ad-TK/Ad-Flt3L gene therapy may be an effective treatment for wtIDH1 gliomas, which could be readily translated to the clinical arena.

cancer biology↗

bioRxiv2025

Human Dermal Fibroblast-derived Spheroids Demonstrate Efficacious Immune Modulation in a Psoriasis Mouse Model

BackgroundPsoriasis is a chronic inflammatory disease associated with high morbidity and few cases of sustained remission. Innovative immunomodulatory therapies, including fibroblast-based cell therapies, offer promising alternatives. This study investigates the therapeutic potential of human dermal fibroblasts (HDFs) organized into three-dimensional (3D) spheroids in a mouse model of imiquimod (IMQ)-induced psoriasis. MethodsHDF spheroids were cultured using Elplasia(R) microcavity plates, and their size, viability, and phenotype were compared with single cells in 2D monolayer cultures. Cellular responses in whole blood and acute inflammatory responses were evaluated at various time points following intravenous injection of HDFs. The therapeutic efficacy of HDF spheroids was assessed using an IMQ-induced psoriasis mouse model, with disease severity scored using the Psoriasis Area and Severity Index (PASI). Optimized HDF spheroids ([~]150 {micro}m, 1x106 cells/mouse) were administered intravenously in a single dose for mild psoriasis or multiple doses for moderate-to-severe psoriasis. The efficacy of HDF spheroids was compared to a pre-clinical monoclonal antibody targeting interleukin 23 (anti-IL-23). ResultsSpheroid cultures of HDFs showed reduced cell size, enhanced viability, and distinct phenotypic changes compared to monolayer cultures. Intravenous injection of HDF spheroids resulted in less thrombocytopenia and reduced acute inflammatory responses compared to single-cell injection. A single dose of HDF spheroids reduced the severity of mild psoriasis by 35%, while repeated doses resulted in a 36% reduction in moderate-to-severe psoriasis. Single-dose administration normalized blood cell counts, alleviated spleen enlargement, and improved cytokine dysregulation. Although HDF spheroids and anti-IL-23 reduced epidermal thickening and immune cell infiltration, HDF spheroids uniquely inhibited monocyte production and infiltration, a benefit not observed with anti-IL-23. No acute or chronic toxicity was observed. ConclusionsHDF spheroids offer comparable therapeutic efficacy to anti-IL-23 in treating psoriasis, with a distinct mechanism involving inhibiting monocyte production and infiltration. Their safety profile and broader immunomodulatory potential support their development as a novel therapeutic strategy for psoriasis and other inflammatory diseases.

immunology↗