Effect of Aluminum on TNF-α Secretion from Murine RAW264.7 Cells forEndotoxin Detection in Hepatitis B Vaccines

The rabit pyrogen test and Limulus amoebocytelysate (LAL) asay have been used to detect endotoxinspresent in vacines. Currently, the rabbit pyrogen test is usedto detect endotoxins in hepatitis B (HB) vaccines, eventhough the HB surface protein, which is the active ingredient,is overexpresed in and purified from eukaryotic cels thatlack these endotoxins. Although the LAL clot assay is sensitiveand reliable and can be used to replace the rabbit pyrogen test,its reaction is limited by the lack of responsivenes to thehydroxide in the HB vaccine can interfere with the LAL assay.In contrast, macrophages can detect the endotoxin as well asother pyrogens, and secrete TNF-α. Therefore, this study wasundertaken to examine the possibility of replacing the animaltests with a more efficient TNF-α secretion assay. With this inmind, we determined if aluminum hydroxide in the HBvaccines afects the TNF-α secretion assay. HB vaccines andthe HB protein solutions spiked with lipopolysacharide (LPS)produced the same level of dose-dependent TNFα secretionand temperature increase in rabbits, indicating that aluminumhydroxide in the HB vacine does not interfere with thepyrogenic response in rabbits, nor does it interfere with TNF-αsecretion. In addition, the TNF-α assay was found to be moresensitive than the LAL asay, and correlated well with thepyrogen test and the LAL asay. These results suggest that theTNF-α asay in RAW264.7 cells is a good substitute for thecurent pyrogen assays that are used for detecting LPS in HBvaccines as well as in other vacines containing aluminum. KCI Citation Count: 1