OBJECTIVETo explore the mechanisms of a novel potassium channel gene named KCTD9 (potassium channel tetramerization domain containing 9) in model of fulminant viral hepatitis induced by murine hepatitis virus 3 (MHV-3).

METHODS78 BALB/cJ mice(6 male) were randomly and equally assigned to two groups, model group of fulminant viral hepatitis induced by MHV3 and its control. 75 C3H/HeJ female mice were done into two groups, 39 for model group of chronic hepatitis induced by MHV3, 36 for control. Various samples including spleen, liver and lymphocytes from mice of two model groups and the controls were examined for KCTD9 expression by real time quantitative PCR and Immunohistochemistry. Independent-samples T test or one-way ANOVA were carried out in different groups.

RESULTSIncreased expressions of KCTD9 mRNA was observed in livers of both model mice of fulminant viral hepatitis and chronic hepatitis. Compared with the control mice, the expressions of KCTD9 mRNA were up-regulated by 577.1-, 8.8-, 59.4- and 10.8-fold in hepatic NK cells, CD4+ T cells, CD8+ T cells and splenic NK cells respectively in model mice of fulminant viral hepatitis 48 hr post MHV-3 infection, whereas down-regulation by 43% and 69% in splenic CD4 + T cells and CD8+ T cells were found respectively. In contrast, in model mice of chronic viral hepatitis the expressions of KCTD9 mRNA were down-regulated by 71% and 51% in hepatic CD4+ T cells and NK cells, respectively. The expression of KCTD9 protein was mainly evidenced in infiltrative mononuclear cells of liver as shown by immunohistochemistry. Basal expression was also investigated and showed constitutive expression of KCTD9 in brain, thymus and other organs in BALB/cJ mice.

CONCLUSIONA novel potassium channel gene KCTD9 was highly expressed in hepatic NK cells and T cells of fulminant hepatitis mice induced by MHV-3.