Costimulatory action of glycoinositolphospholipids from Trypanosoma cruzi: increased interleukin 2 secretion and induction of nuclear translocation of the nuclear factor of activated T cells 1

Abstract

The effects of the glycoinositolphos pholipids (GIPLs) fromTrypanosoma cruzi on T lym phocyte activation were investigated in a mouse T cell hybridoma (DO-11.10). Purified GIPLs from T. cruzi strains Y and G markedly increased IL-2 mRNA transcripts and IL-2 secretion induced by mitogenic anti-CD3 and anti-Thy1 mAbs. This costimulatory function was also revealed by the induction of IL-2 secretion after the simultaneous addition of the T. cruzi GIPLs and either the calcium ionophore A23187 or phorbol ester. The capacity of the GIPL molecule to induce an increase in cytoplasmic cal cium levels was also demonstrated. After exposure of T cell hybridoma to GIPL, the nuclear transcrip tion factor NFAT1 became partially dephosphory lated, and its nuclear localization was demonstrated both in the T cell hybridoma and in Balb/c CD31 cells. These results demonstrate that T. cruzi GIPL molecules are capable of signaling to T cells and therefore could be valuable tools for the study of T cell activation, besides playing a potential role in subverting the T lymphocyte immune response dur ing T. cruzi infection.—Bellio, M., Oliveira, A.-C. S. C., Mermelstein, C. S., Capella, M. A. M., Viola, J. P. B., Levraud, J.-P., Dosreis, G. A., Pre viato, J. O., Mendonc¸a-Previato, L. Costimulatory action of glycoinositolphospholipids from Trypano soma cruzi: increased interleukin 2 secretion and induction of nuclear translocation of the nuclear factor of activated T cells 1.