A model of the role of natural killer cells in immune surveillance--II.

The functioning of natural killer (NK) cells as immune surveillance effector cells against tumors is explored. In part I (J. Math. Biol. 12, 363-373 (1981], it was predicted that susceptible tumors would be eliminated if they have parameter lambda 0 value negative. They would not be eliminated if lambda 0 greater than 0. As the lambda 0 less than 0 result was local, one expected either that tumors of all sizes with lambda 0 less than 0 will be eliminated (global stability) or that tumor population will go to zero if in a domain of attraction of the critical point which is not all of the positive orthant. In this paper, the second is shown to be true. The general results are illustrated by a specific model.