MERCURIC CHLORIDE-INDUCED PROGRAMMED CELL-DEATH OF A MURINE T-CELL HYBRIDOMA .2. OPPOSITE EFFECT OF INTERLEUKIN-2 AND INTERLEUKIN-4

In susceptible animals evidence is accumulating for a primary role for Th2 cells in the course of HgCl2-induced autoimmunity, and for a cont ribution of Th1 cells in the self-regulated phase of this disease. We have reported that incubation of 2B4.11 T cell hybridoma with HgCl2 in duced programmed cell death. This paper shows that recombinant IL-2 si gnificantly diminished HgCl2-induced 2B4.11 cell death. Although no ef fect was observed upon incubation with exogenous IL-4, we observed a s ignificant protection by adding an anti-IL-4 monoclonal antibody to th e culture. Accordingly, by RT-PCR we found the presence of IL-2 recept or-encoding mRNA, and by cytofluorometry, the expression of the protei n was detected only after exposure to HgCl2. Moreover, upon HgCl2 trea tment, 2B4.11 cells were induced to produce IL-4. Altogether these fin dings showed that cytokine environment, IL-2, IL-4 otherwise defining the Th1/Th2 dichotomy, in conjunction with a chemical may differential ly influence the fate of cell populations, death or survival. (C) 1995 Academic Press, Inc.