RNA-seq analysis of integrin β7hi or integrin β7lo PCs, or klf2-sufficient or -deficient PCs

We found that, among newly generated IgG plasma cells, integrin b7hi marks plasma cells prone to home to the bone marrow, whereas integrin b7lo cells remain in secondary lymphoid organs. Moreover, we also found that the differences in KLF2 expression between b7hi and b7lo populations in secondary lymphoid organs is likely to explain that only integrin b7hi plasma cells can egress. Next, to look for the functional target(s) downstream of KLF2 involved in egress of newly generated plasma cells, we carried out RNA-seq analysis of KLF2-sufficient and -deficient splenic plasma cells. Wildtype control splenic plasma cells were further divided into integrin b7hi and b7lo populations. We identified S1pr1 and Itgam as functional targets downstream of KLF2. B6 mice were transferred with splenic B cells from B1-8hi R26-creERT2 CD45.1 Klf2 +/+ or Klf2 fl/fl mice, immunized with NP-CGG in alum and then treated with tamoxifen at day 3, 4, and 5 after immunization. At day 7 after immunization, donor-derived IgG1+ PCs (CD138+ TACI+) derived from Klf2 +/+ or Klf2 fl/fl mice were sorted by using FACSAriaII. In addition, Klf2+/+ PCs were divided into Integrin b7 hi and b7 lo cells and collected as other samples.