on the history of antigen encounter and the stage of T cell activation.РРРРРNaive T cellsРEffector T cellsРMemory T cellsРMigrationРPreferentially to peripheral lymphoid tissuesРPreferentially to inflamed tissuesРPreferentially to inflamed tissues, mucosal tissuesРFrequency of cells responsive to particular antigenРVery lowРHighРLowРEffector functionsРNoneРCytokine secretion; cytotoxic activityРNoneРCell cyclingРNoРYesР+/-РSurface protein expressionРРРРHigh-affinity IL-2 receptorРLowРHighРLowРPeripheral lymph node homing receptor (L-selectin, CD62L)РHighРLowРLow or variableРAdhesion molecules: integrins, CD44РLowРHighРHighРChemokine receptor: CCR7РHighРLowРVariableРMajor CD45 isoform (humans only)РCD45RAРCD45ROРCD45RO; variableРMorphologyРSmall; scant cytoplasmРLarge; more cytoplasmРSmall