Single-Cell Transcriptome Profiling of PBMCs in Response to Diverse Immune Adjuvant Stimuli

Immune adjuvants are agents that enhance the immunogenicity of vaccines when co-administered with antigens. While their primary mode of action involves activation of innate immune pathways in antigen-presenting cells such as myeloid cells—leading to cellular maturation and enhanced antigen presentation—how adjuvants affect other hematopoietic cell types remains largely unclear. To address this, we performed single-cell RNA sequencing of human PBMCs treated with various immune adjuvants, aiming to characterize cell type–specific transcriptional responses at single-cell resolution. Overall design: Human PBMCs were treated for 24 hours with saline, ARNAX-120 (10 µg/mL), poly(I:C) (10 µg/mL), Alum (500 µg/mL), or miR-192-LNP (200 pmol/mL). Following treatment, cells were cryopreserved in CELLBANKER 1(Takara) at –80 °C. For multiplex analysis, cells were barcoded using BioLegend Hashtag DNA. Single-cell capture and reverse transcription were performed using the BD Rhapsody system, and cDNA amplification was carried out using the Terminator-assisted solid-phase cDNA amplification sequencing (TAS-Seq) method (Shichino et al., Commun. Biol., 2022), in collaboration with ImmunoGeneTeqs Inc. The correspondence between samples and tags is as follows: Control (Saline): A0955, ARNAX-120: A0962, poly(I:C): A0963, Alum: A0964, and miR-192-LNP: A0965.