Regulator T Cells带 T-helper: two signals for stimulation by ag Ag fragments presented to T cell by macrophage, dendritic, or activated B cell MHC Class Il; needed for recognition by T-cell receptor and CD4 protein on surface THl cell CD28 protein receptor on TH1 cells CD28 binds to CDgo on macrophage 2nd signal; both go into cytoplasm of TH1 cell BIOL 533 Lecture 7BIOL 533 16 Lecture 7 Regulator T Cells • T-helper: two signals for stimulation by Ag – Ag fragments presented to T cell by macrophage, dendritic, or activated B cell + MHC class II; needed for recognition by T-cell receptor and CD4 protein on surface TH1 cell – CD28 protein receptor on TH1 cells • CD28 binds to CD80 on macrophage 2nd signal; both go into cytoplasm of TH1 cell