Differential contributions of the glycosylphosphatidylinositol (GPI)-anchor and GPI-anchored proteins (GPI-AP) to signalling remain poorly understood. Here we show that GPI-AP deficient murine clones produce on averag...Differential contributions of the glycosylphosphatidylinositol (GPI)-anchor and GPI-anchored proteins (GPI-AP) to signalling remain poorly understood. Here we show that GPI-AP deficient murine clones produce on average 18 and 181-fold more IL-2 mRNA and protein, respectively, upon T cell receptor (TCR) stimulation, in a cell-intrinsic fashion. This phenotype is formally attributed to a mutation within the transferase complex that predicates the initial step in GPI-anchor biosynthesis. Conditional disruption of the transferase complex enabled the generation of primary GPI-AP deficient CD4<sup>+</sup> T cells, which produce on average 10- and 23-fold more IL-2 mRNA and protein, respectively, upon TCR stimulation. Conditional disruption of the transamidase complex yields GPI-sufficient, GPI-AP deficient primary CD4<sup>+</sup> T cells. TCR stimulation of these cells yields levels of IL-2 mRNA and protein ranging from 1 - 3 and 3-fold, respectively, of controls. These results provide the first evidence of a profound impact of GPI in the regulation of TCR signalling.展开更多
基金This work was supported by National Natural Science Foun-dation of China(39779334)Ministry of Public Health Foun-dation(98-1-25)Beijing Natural Science Foundation (798203)
文摘Differential contributions of the glycosylphosphatidylinositol (GPI)-anchor and GPI-anchored proteins (GPI-AP) to signalling remain poorly understood. Here we show that GPI-AP deficient murine clones produce on average 18 and 181-fold more IL-2 mRNA and protein, respectively, upon T cell receptor (TCR) stimulation, in a cell-intrinsic fashion. This phenotype is formally attributed to a mutation within the transferase complex that predicates the initial step in GPI-anchor biosynthesis. Conditional disruption of the transferase complex enabled the generation of primary GPI-AP deficient CD4<sup>+</sup> T cells, which produce on average 10- and 23-fold more IL-2 mRNA and protein, respectively, upon TCR stimulation. Conditional disruption of the transamidase complex yields GPI-sufficient, GPI-AP deficient primary CD4<sup>+</sup> T cells. TCR stimulation of these cells yields levels of IL-2 mRNA and protein ranging from 1 - 3 and 3-fold, respectively, of controls. These results provide the first evidence of a profound impact of GPI in the regulation of TCR signalling.
