Fig. 5.

Repressive function of Tetraodon CD25-like⁺ cells in vitro. a In vitro depletion of Tetraodon CD25-like⁺ leucocytes. The Tetraodon leucocytes were incubated with rabbit anti-CD25-like Abs and complement, and FACs was conducted to analyze the proportion of CD25-like positive cells. A negative control using normal rabbit IgG was devised for the incubation. b, c Functional identifications of Tetraodon Treg-like cells by non-specific cytotoxic cell (NCC) (b) and mixed lymphocyte reaction (MLR) (c) activities in vitro. Figures on the abscissa indicate different effector cells: 1 total leucocytes, 2 CD25-like⁺ depleted leucocytes, 3–5 CD25-like⁺ depleted leucocytes plus CD4-2⁺CD25-like⁺ cells with a proportion of 4:1, 1:1, 1:4, respectively, 6 CD4-2⁺CD25-like⁺ cells. NCC or MLR activities of treated cells had been compared with total leucocytes, with significance indicated by *p < 0.05 and most significant differences indicated by **p < 0.01