Effects of peroxisome proliferators PFOA on immune system of mice

AIM: To examine the effects of peroxisome proliferators (PP), perfluorooctanoic acid (PFOA), on mouse immune system. METHODS: Male C57B/6 mice were received the diet containing PFOA and the following parameters were examined, including weight and cell number of thymus and spleen, cell cycle of thymocytes by PI staining, cell phenotype in thymus and spleen by flow cyto metry (FCM) analysis, IgM and IgG production by the protein-A plaque and ELISA assay, and proliferation of splenocytes in response to ConA or LPS by (3)H-TdR labeling. RESULTS: Severe thymic and splenic atrophy was observed in mice administrated with potent PP, e.g., PFOA. Number of both T and B cells in spleen was decreased upon treatment. Thymocytes were decreased over 90% by treatment, among which the immature CD4(+) CD8(+) population was decreased most dramatically. The most obvious change in thymocytes occurred in the S and G2/M phases. PFOA also prevented the increase both in plaque formation by anti-IgM and -IgG and in serum level of IgM and IgG that normally evoked by immunization with horse red blood cells. Following withdrawal of PFOA from diet, the above parameters rapidly returned to normal. CONCLUSION: Potent PP significantly inhibits mouse immune system.