How can non-specific cytokines act specifically? Only cells expressing receptors for specific cytokines can be activated by them Many cytokines have very short half-lives Only cells in close proximity will be activated High concentrations of cytokines are needed for activation Only cells in close proximity will be activated May require cell-to cell contactHow can non-specific cytokines act specifically? ◼ Only cells expressing receptors for specific cytokines can be activated by them ◼ Many cytokines have very short half-lives ◼ Only cells in close proximity will be activated ◼ High concentrations of cytokines are needed for activation ◼ Only cells in close proximity will be activated ◼ May require cell-to cell contact