Migration of peripheral ASCs on day 6 after TT vaccination. On day 6 after immunization with TT, PBMCs of 6 different donors were tested for their chemotactic responsiveness to CXCL9 (dark gray bars) and CXCL12 (light gray bars). Frequencies of IgG ASCs and TT-specific IgG ASCs attracted by the chemokines were determined in transwell migration assays and were read out by ELISPOT. Frequencies of IgG ASCs (B) and TT-specific IgG ASCs (A) that migrated to the lower chambers of the transwells are shown in relation to input. Mean ± SD of duplicate measurements are indicated.