Abstract
Interleukin-18 (IL-18) is a pro-inflammatory cytokine involved in the Th1 immune response and expressed by a variety of cell types. IL-18 is a member of the IL-1 family and plays an important role in autoimmune diseases and inflammation. Using reverse transcriptase-polymerase chain reaction (RT-PCR) mRNA expression of IL-18, IL-18 receptor alpha (IL-18R alpha), and beta (IL-18R beta) were studied in tumour derived human B-cell lines. Furthermore, we investigated IL-18 protein secretion by using enzyme linked immunosorbent assay (ELISA). The results, as presented in this report, suggest that IL-18, IL-18R alpha, and IL-18R beta mRNA are constitutively and ubiquitously expressed in human B-cell lines, but secretion of the functional protein does not occur. We therefore speculate that IL-18 possibly affects B-cells through paracrine actions.