Regulation of STAT3 signaling in IFNγ and IL10 pathways and in their cross-talk

Unveiling rifampin's impact on OSCC lysate-pulsed DCs: From inflammatory to anti-inflammatory landscape

Dendritic cells (DCs) play a critical role in immune responses, being essential antigen-presenting cells (APCs) for T cell activation. In the context of cancer immunotherapy, DCs are pivotal for eliciting robust CD4+ and CD8+ T cell responses against tumor antigens. However, in oral squamous cell carcinoma (OSCC), DCs encounter challenges due to the immunosuppressive tumor microenvironment (TME). Factors like vascular endothelial growth factor (VEGF) and interleukin (IL)-6 in OSCC hinder DC function and maturation. To address this, current research has focused on enhancing DC immunogenicity to boost anti-tumor immunity. Rifampin, known for its antibacterial properties, presents immunomodulatory effects that could be beneficial in augmenting DC function in cancer therapy. This study investigates the impact of rifampin treatment on OSCC lysate-loaded-DCs. Results show that rifampin enhances the expression of key inflammatory factors while reducing anti-inflammatory mediators in DCs. Moreover, rifampin treatment enhances the immune-stimulatory capabilities of OSCC lysate-loaded-DCs, potentially improving their effectiveness in cancer immunotherapy.

Protein O-GlcNAcylation reprograms macrophage-mediated bone remodeling in medication-related osteonecrosis of the jaw

O-Linked N-acetylglucosamine (O-GlcNAcylation) is an essential nutrient-sensitive post-translational modification (PTM) that has emerged as a critical regulator bridging immunometabolic reprogramming and skeletal homeostasis. Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication of anti-resorptive therapy, with limited effective treatments available. Despite four decades of research since its discovery, the therapeutic potential of targeting O-GlcNAcylation in MRONJ remains underexplored. Macrophages orchestrate a pro-inflammatory/anti-inflammatory milieu by polarization and paracrine signaling to promote bone resorption/formation. However, during MRONJ progression, metabolic alterations reshape macrophage function, leading to immune dysregulation and impaired bone remodeling. O-GlcNAcylation serves as a metabolic sensor of nutritional status and cellular stress, influences macrophage phenotype and function, making it a potential target for therapeutic intervention. Currently, extensive research on biomaterials for bone regeneration primarily focuses on enhancing osteogenesis or inhibiting osteoclast activity, often overlooking the impact of PTMs on bone remodeling. In this review, we highlight the emerging role of O-GlcNAcylation in macrophage regulation, discuss its implications in MRONJ pathogenesis, and explore its potential applications in macrophage-targeted biomaterials and nanotherapeutics.

LPS and type I and II interferons have opposing effects on epigenetic regulation of LAIR1 expression in mouse and human macrophages

Inhibitory immune receptors are important for maintaining immune homeostasis. We identified epigenetic alterations in 2 members of this group, LAIR1 and LAIR2, in lymphoma patients with inflammatory tissue damage and susceptibility to infection. We predicted that the expression of LAIR genes is controlled by immune mediators acting on transcriptional regulatory elements. Using flow cytometry, quantitative reverse-transcription polymerase chain reaction, and RNA sequencing, we measured LAIR1 and LAIR2 in human and murine immune cell subsets at baseline and posttreatment with immune mediators, including type I and II interferons, tumor necrosis factor α, and lipopolysaccharide (LPS). We identified candidate regulatory elements using epigenome profiling and measured their regulatory activity using luciferase reporters. LAIR1 expression substantially increases during monocyte differentiation to macrophages in both species. In contrast, murine and human macrophages exhibited opposite changes in LAIR1 in response to immune stimuli: human LAIR1 increased with LPS while mouse LAIR1 increased with interferon γ. LAIR genes had distinct patterns of enhancer activity with variable responses to immune stimuli. To identify relevant transcription factors (TFs), we developed integrative bioinformatic techniques applied to TF chromatin immunoprecipitation sequencing, RNA sequencing, and luciferase activity, revealing distinct sets of TFs for each LAIR gene. Most strikingly, LAIR1 TFs include nuclear factor kappa B factors RELA and RELB, while Lair1 and LAIR2 instead include STAT3 and/or STAT5. Regulation by nuclear factor kappa B factors may therefore explain the LPS-induced increase in LAIR1 expression, in contrast to Lair1 decrease. Our findings reveal new insights into transcriptional mechanisms that control distinct expression patterns of LAIR genes in response to inflammatory stimuli in human and murine myeloid and lymphoid cells.