HLA-DPB1 and infection: Initially, thawed PBMCs from 6 subjects at baseline and 4 subjects on day 10 after infection were stained with class II–associated invariant peptide tetramers (CLIP negative control) and G-DDF/DPB1*04:01 tetramers using optimized conditions (Figure 8A and Supplemental Figure 8A for gating strategy).