Freshly isolated PBMC were aliquotted for ex vivo analysis, with random assignment to HA control tests and citrulline peptide tests, where the total number of ex vivo tetramers tested was dependent on the number of PBMC available. All samples for ex vivo analysis were labeled, enriched (20 (link)) and subjected to phenotypic analysis as previously described (21 (link)). Briefly, 40 million PBMC in 200 µl of T cell culture medium were treated with dasatinib for 10 minutes at 37°C and then stained with 20 µg/ml PE-labeled tetramers at room temperature for 90 min. Cells were washed and incubated with anti-PE magnetic beads (Miltenyi Biotec) at 4°C for 20 minutes, washed again, and a 1/100th fraction saved for analysis. The other fraction was passed through a magnetic column (Miltenyi). Bound, PE-labeled cells were flushed and collected. Both enriched and non-enriched fractions were labeled with CD4 V500 (BD), CXCR3 Pacific Blue (BioLegend), CD45RO eFlour 650 NC (eBioscience), CD28 PE-Cy7 (BioLegend), CCR7 Alexa-700 (BD), CD25 APC (BD), CCR6 PerCP-Cy5.5 (BD), and CD14 (BioLegend), CD19 (BioLegend), & Annexin V (BD) conjugated in FITC. Samples were then run on a BD LSRII flow cytometer, and data was analyzed using FlowJo software version 9.6.2.