Figure 3. (A) Principal component analysis highlights transcriptional differences between the HIV-positive older adults and all other cohorts. Principal component analysis was performed to identify age, HIV, and Dectin-1 stimulation associated differences among Inflammatory (CD14+CD16+) monocytes. Dectin-1 stimulated vs. unstimulated Inflammatory monocytes were separated with 16% variance on PC2, and monocytes from HIV older adults vs all other cohorts are separated by 53%. [HIV-Older n= 4, HIV-Young n =4, Young = 3, Young* = 4, Older = 3]. Please note that the asterisk (*) indicates the presence of co-morbidities. None = Unstimulated, WGP= Dectin-1 stimulation. (B) Heatmap of top 100 variable genes. A total of 314 (Young (Y)), 541 (Young * (Y*)), 402 (Older (O)), 860 (HIV-Young (HIV-Y)), and 156 (HIV Older (HIV-O)) unique DEG (differentially expressed genes) were noted for each of the cohorts respectively. The genes with a fold change of (FC) 1.2 and FDR < 0.1 were defined as differentially expressed genes (DEGs). This heat map notes differences in HIV Older vs. all other cohorts–the effect of stimulation is seen in the second row (Pink column). The heatmap was constructed using Pheatmap. The transcripts were normalized using variance stabilizing transformation function. The color represents relative expression of transcripts that covary across cohorts and condition.