Paraquat reduces natural killer cell activity via metallothionein induction. (October 2015)

• Record Type: Journal Article
• Authors: Lim, Joo Hyuk; Won, Jong Hoon; Ahn, Kyong Hoon; Back, Moon Jung; Fu, Zhicheng; Jang, Ji Min; Ha, Hae Chan; Jang, Yeo Jin; Kim, Dae Kyong
• Is Part Of: Journal of immunotoxicology. Volume 12:Number 4(2015)
• Page Start: 342
• Page End: 349
• Publication Date: 2015-10
• Subjects: Immunotoxicology -- Periodicals; Poisons -- Immunology -- Periodicals; Environmental health -- Periodicals; 616.97
• Languages: English
• ISSNs: 1547-691X

Abstract

<abstract> <title>Abstract</title> <p>Paraquat (PQ), one of the most widely used herbicides, has been used for several decades in agriculture. Some studies suggest that PQ has effects on the immune system. Moreover, previous studies have shown that PQ imparted some immunosuppressive effects. In the present study, cytotoxicity assays using splenic NK cells from mice treated for 28 days with PQ (at 0.2, 1, and 5 mg/kg) were performed to determine whether PQ altered the function of NK cells. Given that PQ was expected to induce an immunosuppressive effect, it was hypothesized that a gene involved in cellular metal ion homeostasis, metallothionein-1 (MT-1), could play an important role in this outcome. This belief was based on the fact that <italic>MT1</italic> encodes a protein responsible for zinc ion homeostasis, and that a reduction in free zinc ion levels impairs NK cell function. The results showed that PQ treatments led to increased MT expression in several organs (liver, kidneys, testes) and in splenocytes, caused a reduction of both free zinc ions in sera and in free intracellular zinc, and reduced the expression of GATA-3, a zinc-finger transcription factor important for maturation and activity of T-cells and NK cells. These results provide a basis for a new molecular mechanism to describe potential immunosuppressive effects of PQ <italic>in vivo</italic>.</p> </abstract>