Structure and expression of human B cell stimulatory factor-2 (BSF-2/IL-6) gene.

Abstract

The chromosomal DNA segment of human B cell stimulatory factor‐2 (BSF‐2/IL‐6) was isolated and characterized by nucleotide sequence analysis. The human BSF‐2/IL‐6 gene consists of five exons and four introns and its organization shows a distinctive similarity to granulocyte colony‐stimulating factor gene. The two genes have the same number of exons and introns and the size of each exon is strikingly similar. The BSF‐2/IL‐6 mRNA was found to be constitutively expressed in a human T cell leukemia virus‐1 transformed T cell line, TCL‐Na1, a bladder cell carcinoma line, T24, and an amnion derived cell line, FL. The BSF‐2/IL‐6 mRNA was also found to be inducible with interleukin‐1 beta in an astrocytoma line, U373 and a glioblastoma line, SK‐MG‐4. S1 mapping and primer extension analyses showed the presence of multiple initiation sites and the preferential utilization of a different initiation site for each individual tissue tested.