Extraction of total RNA, reverse transcription into complementary DNA, and the subsequent real-time PCR were all performed as previously described45. We used primer/probe sets of the TaqMan Gene Expression Assays for mouse CD11c, CD138, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), all obtained from Thermo Fisher Scientific (Waltham, MA). The relative amount of mRNA was calculated using the comparative Ct (∆∆Ct) method. All amplification products were normalized against GAPDH mRNA, which was amplified in the same reaction as an internal control.