T-cell immunity in the induction and maintenance of a tumour dormant state.

We conclude from animal tumour model studies that T cell immunity can play an essential role in the induction and maintenance of tumour dormancy. Evidence was found in tumour dormancy situations for active control of proliferating tumour cells by CD8 memory T cells leading to a long-term balance in the bone marrow between low numbers of tumour cells and immunological memory. In breast cancer patients, too, the bone marrow may represent a privileged compartment for tumour dormancy and immunological memory. Upon restimulation with tumour antigen pulsed autologous dendritic cells, bone marrow-derived memory T cells from cancer patients could be shown to exist and to become activated into potent anti-tumour effector cells. Copyright 2001 Academic Press.