EDF1 accelerates ganglioside GD3 accumulation to boost CD52-mediated CD8+ T cell dysfunction in neuroblastoma.

Background: Heterogeneous clinical features and prognosis in neuroblastoma (NB) children are frequently dominated by immune elements. Dysfunction and apoptosis in immune cells result from the exposure to continuous tumor-related antigen stimulation and coinhibitory signals. To date, key factors pointing to the restriction of NB-specific CD8⁺ T cells remain elusive.

Methods: We performed bulk-RNA sequencing and lipidomic analyses of children with mediastinal NB. Bioinformatics analysis and biological validation were applied to uncover the underlying mechanism.

Results: Three subtypes were identified using nonnegative matrix factorization (NMF), among which we highlighted an apoptotic status of infiltrated CD8⁺ T cells, along with the highest CD52 and EDF1 expression in Cluster3 (C3) subtypes. It was verified that high EDF1 expression in NB cells led to Lactosylceramide (LacCer) accumulation, as well as downstream ganglioside-GD3, which subsequently increased the expression of CD52 and immune checkpoint genes, chemotaxis, and apoptosis-related events in activated CD8⁺T cells. Mechanistically, EDF1 was recruited as a coactivator to form the NF-κB/RelA/EDF1 complex, which further prevented the promoter region methylation of ST8SIA1, to elevate its transcription.

Conclusion: These findings characterize abundant GD3 in NB cells, which regulated by the EDF1/RelA/ST8SIA1 axis, is responsible for CD8⁺ T cell dysfunction. Inhibition of EDF1 may reduce suppressive factors and prevent immune escape of NB cells. Modulating NB-associated GD3 levels through metabolic intervention is beneficial for tuning the depth and duration of responses to current NB therapies. The integration of transcriptomic and lipidomic data offers a more comprehensive understanding of the interaction between LacCer metabolites and the immune status in NB.