Coding region structure of interleukin-8 gene of human lung giant cell carcinoma LU65C cells that produce LUCT/interleukin-8: homogeneity in interleukin-8 genes.

A 1.9-kb fragment containing an interleukin-8 (IL-8) coding region was amplified by the polymerase chain reaction (PCR) from the genomic DNA of human lung giant cell carcinoma LU65C cells that produce LUCT/IL-8 with N-terminal sequence of AVLPR. The coding region was found to consist of 4 exons and 3 introns as identical as that of the gene of MDNCF/IL-8 lacking N-terminal AVLPR. PCR using genomic DNAs from human polymorphonuclear leukocytes and mononuclear cells also provided the same 1.9-kb fragment as that from LU65C genomic DNA. Thus, it seems likely that human cells possess IL-8 genes with the homogeneous coding region so that they may first produce the same mature protein with N-terminal AVLPR (= LUCT) which was then truncated.