General Characteristics of DTH An exaggerated interaction between antigen and normal CMI-mechanisms Requires prior priming to antigen Memory T-cells recognize antigen together with class II MHC molecules on antigen-presenting cells Blast transformation and proliferation Stimulated T-cells release soluble factors (cytokines) Cytokines attract and activate macrophages and/or eosinophils help cytotoxic T-cells become killer cells,which cause tissue damage General Characteristics of DTH ◼ An exaggerated interaction between antigen and normal CMI-mechanisms ◼ Requires prior priming to antigen ◼ Memory T-cells recognize antigen together with class II MHC molecules on antigen-presenting cells ◼ Blast transformation and proliferation ◼ Stimulated T-cells release soluble factors (cytokines) ◼ Cytokines ◼ attract and activate macrophages and/or eosinophils ◼ help cytotoxic T-cells become killer cells, which cause tissue damage