Single cell analysis informs efficient reprogramming of human somatic cells to dendritic cells type 1

ABSTRACT: Type-1 dendritic cells (DC1s) are critical cellular mediators of anti-tumor immunity, as their ability to prime CD8+ T-cells is crucial for response to checkpoint blockade and adoptive T-cell transfer. Vaccination strategies to harness this unique DC subset for immunotherapy have been limited by their rarity in peripheral blood and lack of homogeneous alternative cell sources. We have previously identified PU.1, IRF8 and BATF3 transcription factors (TF) as sufficient to induce DC1 program in mouse fibroblasts but reprogramming efficiency in human cells was low. Here, we investigated single-cell transcriptional dynamics during human DC1 reprogramming. Human induced DC1s (hiDC1s) generated from embryonic fibroblasts acquire global DC1 transcriptional profile and activate antigen presentation signatures. Interestingly, other DC subsets are not induced at the single cell level. We extracted gene modules associated with successful reprogramming and identified inflammatory signaling and the DC1 reprogramming TF network as key drivers of the process. Combining inflammatory cytokine signaling with TF constitutive overexpression lead to improved reprogramming efficiency by 190-fold. HiDC1s acquire the ability to uptake dead cells, respond to stimuli, secrete inflammatory cytokines and perform antigen presentation. Remarkably, intra-tumoral vaccination in mouse models increased infiltration of antigen-specific CD8+ T-cells, promoted a T-cell cytotoxic profile and conferred protection against tumor growth. Finally, we demonstrated efficient hiDC1 generation from human adult somatic cells including dermal fibroblasts and mesenchymal stem cells with a xeno-free protocol. These findings provide insights into human DC1 specification and reprogramming and represent a platform for generating patient-specific DC1s, a long-sought DC subset for cancer immunotherapy.

ORGANISM(S): Homo sapiens

PROVIDER: GSE189612 | GEO | 2022/03/08

REPOSITORIES: GEO