The role of monovalent cations in the interaction between the cytotoxic T lymphocyte and its target

Evidence is provided for the participation of monovalent cations in both the binding and lytic phases of the lytic cycle. There appears to be one sodium requirement in the cytotoxic T lymphocyte‐target binding event (effective dose₅₀ ∼ 35 mM) and possibly another sodium requirement in the delivery of the lethal hit (ED₅₀ <7 mM). Potassium can replace sodium in the binding event but antagonizes the lethal hit phase (inhibitory dose₅₀ ∼ 110 mM). Lithium antagonizes the binding event (ID₅₀ ∼ 15 mM).