Project description:Here we present high-resolution mass spectrometry analysis of changes to the phosphoproteome of cytotoxic T lymphocytes (CTL) induced by the cytokine, Interleukin 12 (IL-12). We treated CTL with a short and long IL-12 stimulation and mapped the changes to the phosphoproteome using quantitative SILAC-based phosphoproteomics.
Project description:CD8+ cytotoxic T lymphocytes (CTLs) play a major role in defense against intracellular pathogens, and their functions are specified by antigen recognition and innate cytokines. While effector CTLs eliminate the infection, a small population of memory cells are retained that yields more rapid and robust response upon re-infection. Antigen presenting cells secrete an array of innate cytokines including IL-12 and IFN-α after recognition of pathogens. Both IL-12 and IFN-α have been shown to act as the third signal regulating the development of CTLs. We have shown that these two cytokines have a non-redundant effect in generation of human effector CTL. IL-12 alone is sufficient for effector CTL genesis marked by IFN-γ and TNF-α production, as well as increased cytolytic activity. Even in the presence of IFN-α, IL-12 programs CTLs that express the chemokine receptor CXCR3 and effector cytokines. Using microarray analysis we have investigated how IL-12 and IFN-α differentially regulate the genetic programming pathways that give rise to effector CTLs among multiple human donors. We have also analyzed the gene expression patterns of cells sorted from healthy human peripheral blood that display surface markers of effector memory CTL (designated as ex vivo) samples.
