Evaluation of exosome-dependent NF-κB activation in head and neck carcinoma

Introduction Head and neck squamous cell carcinoma (HNSCC) are highly immunosuppressive tumors and show increased NF-κB activation. The immunosuppressive effects are caused by inhibitory cytokines but also by tumor-derived exosomes (TEX) in the tumor microenvironment (TME). Exosomes are small extracellular vesicles that can move freely in all body fluids and mediate cell-to-cell communication. TEX contain immunomodulatory molecules influencing the function of immune cells. In this study, we investigate the influence of patient derived exosomes on the NF-κB signaling pathway in context of HNSCC.

Methods Exosomes were isolated from plasma of HNSCC patients by size-exclusion chromatography. TEX were co-incubated with primary macrophages with and without NF-κB inhibitors to assess the effect on NF-κB and its downstream signaling pathways. NF-κB activation was measured by Western Blot and nuclear Translocation-Assay. Downstream effects were evaluated by qPCR for CCL5, CXCL10, CCL22, IDO, TNFα and IFNβ, chemokine ELISA and T-cell migration assays. Results TEX were internalized by macrophages and NF-κB activation was visible after 2h of coincubation. This activation was reversible by NF-κB inhibitors especially curcurmin. In macrophages co-incubated with TEX, NF-κB-dependent downstream chemokines modulated the migration of cytotoxic CD8+ and regulatory T-cells.

Discussion Exosomes from plasma of HNSCC patients interact with macrophages and can activate the NF-κB signaling pathway. This effect is reversible by NF-κB inhibitors and therefore shows potential to be considered as a future therapeutic target.

Publication History

Article published online:
12 May 2023