Evaluation of Hybridoma B9 cell line handling of Cadmium in the presence of Interleukin-6

Induction of metallothionein synthesis in the presence or absence of Interleukin -6 (IL-6) was one of the responses examined to identify the the mechanism by which IL-6 (at high concentration) was able to reverse cadmium inhibition of B9 cell line proliferation. Cellular metallothionein was assayed by Cd-haem method. The results revealed a Cd-induced increase in cellular metallothionein synthesis. IL-6 alone was not sufficient to induce expression of metallothionein in this cell line. The Kinetics of B9 cells handling of cadmium (using radio active ¹⁰⁹Cd as tracer) was another response examined. Cells were pre-loaded with ¹⁰⁹Cd then transferred to ¹⁰⁹Cd-free medium containing IL-6. The results shows the efflux of Cd from IL-6 stimulated B9 cells which suggest that there is no functional linkage between IL-6 stimulation and cellular handling of Cd. The efflux of cadmium out of the cells is however an important observation in that many function assays used in immunotoxicology are carried out in-vitro after cellular exposure to the chemical in-vivo. In the interpretation of such data, the ability of the cells to recover as a result of cellular efflux of the chemical should always be considered. @JASEM