Effect of poly(I:C) on the activation of head kidney macrophages (HKM) and peripheral blood leukocytes (PBL).

<p>(A) Flounder were treated with or without (control) different concentrations of poly(I:C); at different days post-treatment, HKM were collected from the fish and examined for respiratory burst activity. (B) PBL collected from flounder treated with or without (control) poly(I:C) were used as effector cells, while PBL collected from megalocytivirus-infected flounder were used as target cells. The effector (E) and target (T) cells were mixed at different ratios and incubated at 22°C for 24 h. The cytotoxicity of the effector cells was then determined by LDH assay. For both panels, data are presented as means ± SE (<i>N</i> = 3). <i>N</i>, the number of experimental repeat. *<i>P</i><0.05; **<i>P</i><0.01.