Methylation patterns were examined in IL-13 promoter sequences from −280 to +58. (A) The IL-13 promoter contains 7 CpG sites at the positions indicated, between −280 and +58 relative to the transcription start site. Genomic DNA was harvested from L428 cells, BJAB cells, primary uninfected B cells, and 11 LCLs, and CpG methylation was analyzed by bisulfite sequencing. Numbers (1-7) under the sequence represents the CpG position; [□], nonmethylated CpG; [■], methylated CpG. (B) In total, 6 LCLs cells were infected with pSIN-Zta or pSIN-vector lentivirus at an MOI of 4. Genomic DNA was extracted, and CpG methylation was analyzed by bisulfite sequencing after 7 days. (C) L428 cells, BJAB cells, and a total of 10 LCLs were treated with or without 2.5 μM 5-azacytidine for 5 days. Cultured supernatants were harvested, and IL-13 expression was measured by ELISA.