Immune system cells communicate via cytokines 。Interleukin-1 Stimulates TH cells 。Interleukin-2 Activates TH,B,Tc,and NK cells 。Interleukin-12 Differentiation of CD4 cells 。y-Interferon Increase activity of macrophages Chemokines Cause leukocytes to move to an infection• Interleukin-1 Stimulates TH cells • Interleukin-2 Activates TH, B, TC, and NK cells • Interleukin-12 Differentiation of CD4 cells • -Interferon Increase activity of macrophages • Chemokines Cause leukocytes to move to an infection Immune system cells communicate via cytokines