Characteristics of a CCL21-gene modified dendritic cell vaccine utilized for a clinical trial in non-small cell lung cancer

Samples are from a phase I clinical trial of a vaccine consisting of monocyte-derived DCs (moDCs) modified to express the chemokine CCL21 given in combination with pembrolizumab, conducted in patients with advanced non-small cell lung cancer. Single cell RNA sequencing of pre- and post-transduced vaccines was performed to characterize the cellular composition of these vaccines and assess the trascriptional impact of the transduction process. The same vaccine production procedure was also applied to blood obtained from healthy donors to investigate the effects of donor source on DC vaccine phenotype. Overall design: Monocyte-derived dendritic cells isolated from PBMCs of patients and health donors were modified to express the chemokine CCL21. We used single-cell RNA sequencing to evaluate 1) the cellular composition and transcriptional impact of the transduction process in patient samples and 2) their deviation between patients and healthy donors upon the transduction.