Figure 7

High-dimensional analysis of YF-specific T-cell memory response in adults following 17DD-YF 1/5 fractional dose primary vaccination. T-cell memory profile was characterized upon long-term in vitro PBMC cultures carried out before [NV_(D0) = ▭, n = 15] and 30–45 days after [PV_(D30–45) = ▬, n = 15] 17DD-YF 1/5 fractional dose primary vaccination. PBMC cultures were performed in the absence (unstimulated—Control Culture) and in the presence of 17DD-YF antigen (17DD-YF stimulated—17DD-YF Culture). Immunophenotyping staining of memory phenotypes of CD4⁺ and CD8⁺ T-cell subsets (Naïve—CD45RA⁺CCCR7⁺ = ; Central Memory—CD45RA⁻CCCR7⁺ = ; Effector Memory—CD45RA⁻CCCR7⁻ =  and Terminal Effector—CD45RA⁺CCCR7⁻ = ) as well as B-cells (Naive—IgD⁺CD27⁻ = ; Double-Negative—IgD⁻CD27⁻ = ; Classical Memory—IgD⁻CD27⁺ =  and Non-Classical Memory—IgD⁺CD27⁺ = ) was carried out by mass cytometry by time-of-flight (CyTOF) as described in “Methods” section. Dimensionality reduction of Mass Cytometry data was performed using tSNE (t-distributed Stochastic Neighbor Embedding) to visualize high-dimensional data of memory T and B-cells with supervised selection strategy as described in “Methods” section. A total of 5000 iterations were carried out using CD3, CD4 or CD8, CD45RA and CCR7 parameters for T-cells and CD19, CD20, CD21, IgD and CD27 parameters for B-cells. The hyperparameters tSNE_1 and tSNE_2 were visualized as heatmaps. The number of events for each memory cell phenotype was calculated considering a total of 10,000 events for CD4⁺ T-cells, 8000 for CD8⁺ T-cells and 6200 for B-cells.