Previously frozen PBMCs from only before and 24 hours after IFN-α2b (41 (link)) were thawed, washed, and incubated with CD3-FITC (BioLegend), CD4-PE/Cy7 (BioLegend), CD8-APC (BD Biosciences), HLA-DR–PE (BioLegend), and CD38-BV421 (BioLegend) antibodies for 40 min at 4°C as per the manufacturers’ recommendation. Immediately before sorting, plasma membrane–compromised cells were labeled with propidium iodide (Sigma-Aldrich). FACS was performed on a MoFlo Legacy Sorter (Beckman Coulter) at the Johns Hopkins School of Public Health Flow Cytometry Core Facility. The population of interest was sorted directly into ≥4 volumes of Quick-RNA MicroPrep lysis buffer (Zymo Research) as per the manufacturer’s recommendation. Sorting was stopped when the number of sorted cells reached 125,000 cells, although many samples did not reach this number. Flow cytometry analysis on two randomly selected post-sort samples revealed >95% purity. Sorted samples were vortexed, incubated for 10 min at room temperature, vortexed again, and frozen at −80°C until isolation.