ABSTRACT
It is known that T cells from cancer patients or tumor-bearing mice (TBM) are in a suppressed state and exhibit poor immune responses. Several different mechanisms have accounted for this suppression, in cluding downregulation of growth factors, production of immunosup pressive cytokines, and the contributions by suppressive macrophages and suppressive T cells. Recently, it has been shown that T cells from patients with advanced cancer or TBM show abnormal structure of the T-cell receptor (TCR)-CD3 complex, particularly the disappearance of the CDЗζ (1-6). The disappearance of Ο ϋ3ζ in tumor-bearing status appears to be related to the proliferative response of T cells (1), and the degree of the decrease of Ο ϋ3ζ seems to correlate with tumor progres sion in cancer patients (2-4) and TBM (5).
