Detection of ST2L message in Th2s. RNA from a panel of four each of different Th1 (Dorris, X4, X9, and X17) and Th2 (D10, D2.2, D2.3, and X12) clones (resting cells, two wk after antigen stimulation) were extracted and compared by DD-PCR. (a) Two representative patterns comparing the PCR products from Dorris (Th1) and D10 (Th2) cells, using two different primer pairs (lanes 1 and 2, H-T11A/H-AP34; lanes 3 and 4, H-T11G/H-AP34). Arrowhead, the ST2L band. (b) Nucleotide sequence of one cDNA present in Th2s, but not in Th1s. This has complete homology with the 3′ terminus of ST2L cDNA. (Data are available from EMBL/GenBank/DDBJ under accession number D13695.) The primer (H-T11A/H-AP34) binding sites are underlined. (c) Northern blot analysis detected ST2L in D10, but not in Dorris cells. Similar results were obtained for the other three Th1 and Th2 clones (not shown). (d) Reverse transcriptase PCR Southern demonstrates the presence of ST2L message in Th2, but not in Th1, clones. c and d are representative of three experiments.